HARQ-ACK reporting with PDSCH grouping

A wireless device receives downlink control information (DCI) from a network node, determines a physical downlink shared channel (PDSCH) group based on information in the received DCI, and transmits a hybrid automatic hybrid automatic repeat request acknowledgement (HARQ-ACK) report to the network node based on the determined PDSCH group.

TECHNICAL FIELD

The disclosed subject matter relates generally to telecommunications. Certain embodiments relate more particularly to concepts such as wireless communication in unlicensed spectrum, 5G New Radio (NR), NR Unlicensed (NR-U), hybrid automatic repeat request acknowledgement (HARQ-ACK) reporting, and physical downlink shared channel (PDSCH) grouping.

BACKGROUND

NR provides flexibility in HARQ feedback timing to account for dynamic time-division duplexing (TDD) and to possibly combine several HARQ feedbacks for both lower overhead and higher reliability.

Figure (FIG. 1shows an example of HARQ feedbacks for dynamic TDD, with data transmissions illustrated by shaded boxes in the downlink (DL), and the HARQ feedbacks illustrated by shaded boxes in the uplink (UL). The slot timing or offset (hereafter, “K1”) between DL data transmission and acknowledgement is determined based on a 3-bit field in downlink control information (DCI). Radio Resource Control (RRC) signalling configures the set of eight (8) values to be indexed by K1 (possible value range is {0, 1, . . . , 15}).

HARQ codebook size in time (DL association set) is determined based on the configured set of HARQ-ACK timings K1, physical downlink control channel (PDCCH) monitoring occasions, and semi-static configured TDD pattern. For each slot, a user equipment (UE) may report a HARQ feedback bitmap of fixed size according to its carrier aggregation (CA) and transport block/codeblock group (TB/CBG) configuration (in this example 7 bit); not received TB/CBG are set to NACK.

A dynamic HARQ codebook provides the possibility to dynamically determine the set of HARQ process for which the HARQ feedback should be reported. The DCI typically includes a downlink assignment indicator (DAI) that indicates the number of HARQ process that should reported, and a PDSCH to HARQ-ACK timing that specifies time resource in which a network node (e.g. gNB) is expecting the feedback.

The UE refers to the DAI value to calculate the dynamic codebook size. For every PDSCH transmission, the DAI value in the DCI is incremented. The DAI in the DL scheduling DCI is typically stepped by one as compared to the immediate preceding DL scheduling DCI, if not, it is an indication that PDSCH transmission(s) has been missed. The difference between the two received DAI values at the UE in current and earlier DCI indicates how many PDSCH transmissions were missed.

DAI indicates the number of HARQ process that should reported. The DAI value in NR rel-15 is only 2-bits (representing 4 possible values 0,1,2,3), so after reaching the highest DAI value (i.e. 3), the DAI wraps around and starts again from the smallest value.FIG. 2shows an example of changing DAI values.

Transmissions on unlicensed bands are subject to a listen before talk (LBT) procedure, therefore there is uncertainty if the transmission will go through or not depending on the LBT outcome.

First, if HARQ feedback transmission in uplink control information (UCI) is subject to LBT, there is a risk that the UE fails to perform the transmission depending on the LBT outcome. Due to the one-to-one mapping between PDSCH and corresponding feedback in the time domain, if the UE fails to transmit the feedback on the predefined time location, the gNB will have to assume a negative acknowledgement (NACK) and retransmit all the corresponding PDSCHs. The latter can be considered as an inefficient utilization of the band, and it also causes unnecessary increase in the channel contention.

Second, even if the UE successfully transmits the HARQ feedback, there are chances that the gNB may not be able to detect it. From gNB perspective, failed LBT or missed UCI transmissions are indistinguishable. Due to the one-to-one mapping between PDSCH and corresponding feedback in the time domain, if the gNB fails to detect the feedback in the predefined time location, the gNB will have to assume NACK and retransmit all the corresponding PDSCHs.

In view of these limitations, 3GPP agreed to support mechanisms to allow retransmission of the HARQ feedback.

The following was agreed in RAN1#96bis.

Restrict further discussion on HARQ codebook to the following:For dynamic HARQ codebook:PDSCH grouping by explicitly signalling a group index in DCI scheduling the PDSCHgNB can request HARQ-ACK feedback in the same PUCCH for all PDSCHs in the same groupOption 1:One PUCCH can carry HARQ-ACK feedback for one or more PDSCH groupsDCI can request HARQ-ACK feedback for one or more PDSCH groupsFFS one of the two options belowC-DAI/T-DAI can be accumulated across multiple PDSCH groups for which feedback is requested in the same PUCCHC-DAI/T-DAI is accumulated only within one PDSCH groupFFS: New ACK-Feedback Group Indicator for each PDSCH GroupThe number of HARQ-ACK bits for one PDSCH group is constant between a first HARQ-ACK feedback transmission and a HARQ-ACK feedback re-transmission, i.e. the PDSCH group cannot be enlarged after the first feedback transmissionOption 2:One PUCCH can carry HARQ-ACK feedback for a single PDSCH groupFFS: Feedback for more than one PDSCH groupDCI can request HARQ-ACK feedback for a single PDSCH groupFFS: Requests for more than one PDSCH groupC-DAI/T-DAI is accumulated within one PDSCH groupA reset indicator signals new HARQ-ACK feedback for a PDSCH groupThe number of HARQ-ACK bits for one PDSCH group may not be constant between a first HARQ-ACK feedback transmission and a HARQ-ACK feedback re-transmissionSemi-static codebook. Options FFS.If request/trigger for one-shot group HARQ ACK feedback for all configured HARQ processes is introduced (at least for non-CBG HARQ), select one or more of the following candidate schemes:The request is carried in a UE-specific DCI carrying a PUSCH grantThe request is carried in a UE-specific DCI carrying a PDSCH assignmentThe request is carried in a UE-specific DCI not scheduling PDSCH nor PUSCHThe request is carried in a UE-common DCIThe request can be used for UE configured with dynamic or semi-static HARQ codebook

SUMMARY

In certain embodiments of the disclosed subject matter, PDSCH grouping and single-shot trigger are configured and implemented for NR-U operation, or alternatively for operation in licensed spectrum and/or a combination of licensed and unlicensed spectrum.

In certain embodiments, a method of operating a wireless device comprises receiving downlink control information (DCI) from a network node, determining a physical downlink shared channel (PDSCH) group based on information in the received DCI, and transmitting a hybrid automatic hybrid automatic repeat request acknowledgement (HARQ-ACK) report to the network node based on the determined PDSCH group.

In certain related embodiments, the method further comprises receiving radio resource control (RRC) configuration information for at least one PDSCH group, wherein determining the PDSCH group comprises identifying a PDSCH group index within the DCI based on the received RRC configuration information. In some such embodiments, the RRC configuration information comprises at least one of (a) an indication of whether PDSCH grouping functionality is enabled with respect to the wireless device, (b) a maximum number of PDSCH groups, (c) a maximum number of PDSCH per PDSCH group, and (d) an indication of whether a reset indicator that signals new HARQ-ACK feedback for a PDSCH group is enabled. In some other such embodiments, the DCI comprises at least one of (a) a PDSCH group index field, and (b) a reset or request indicator that signals new HARQ-ACK feedback. The reset or request indicator could comprises, e.g. a bit map of PDSCH groups configured on a cell, with a corresponding bit mapped to each of the PDSCH groups.

In certain related embodiments, determining the PDSCH group based on the information in the received DCI comprises identifying a HARQ process identifier in the DCI; and determining the PDSCH group based on the HARQ process identifier.

In certain related embodiments, determining the PDSCH group based on the HARQ process identifier comprises associating a HARQ processes identifier with a PDSCH group based on at least one bit at least one or more predetermined positions in the HARQ process identifier.

In certain related embodiments, the method further comprises determining whether a HARQ feedback indicator is conveyed in a downlink data assignment DCI that includes a PDSCH-to-HARQ timing indicator and a physical uplink control channel (PUCCH) resource indicator for the HARQ-ACK report, and in response to the determination, jointly encoding HARQ feedback for the PDSCH group with HARQ for a PDSCH being scheduled by the downlink data assignment DCI.

In some embodiments of the disclosed subject matter, a wireless device comprises processing circuitry and transceiver circuitry collectively configured to perform a method as indicated above.

In some embodiments of the disclosed subject matter, a method of operating a wireless device comprises receiving, from a network node, a trigger for a hybrid automatic repeat request acknowledgement (HARQ-ACK) report, and in response to the trigger, transmitting, to the network node, the HARQ-ACK report, wherein the HARQ-ACK report comprises a new data indicator (NDI) value for a latest received physical downlink shared channel (PDSCH), along with HARQ feedback for the latest received PDSCH.

In certain related embodiments, the wireless device transmits the NDI and HARQ feedback for the latest PDSCH according to at least one of the following: (a) the wireless device receives a retransmission for an identified HARQ process and reports HARQ feedback for the identified HARQ process after soft combining with the latest received PDSCH, (b) the wireless device misses a retransmission for an identified HARQ process and reports HARQ feedback for the identified process based on a previous received PDSCH, (c) the wireless device receives a new PDSCH transmission for an identified HARQ process and reports HARQ-ACK feedback for the identified process based on the new PDSCH transmission, and (d) the wireless device misses a new transmission for an identified HARQ process and reports HARQ feedback for the identified process based on a previous received PDSCH.

In certain related embodiments, the trigger comprises information indicating a subset of configured HARQ processes to be reported in the HARQ-ACK report.

In certain related embodiments, the HARQ-ACK report comprises 2*H HARQ-ACK bits for HARQ processes, and wherein a corresponding HARQ codebook corresponds to an H*2 array with entries (h, b) each corresponding to a HARQ process h and an NDI value b.

A wireless device comprising processing circuitry and transceiver circuitry collectively configured to perform a method according to any of claims10-13.

In some embodiments of the disclosed subject matter, a wireless device comprises processing circuitry and transceiver circuitry collectively configured to perform a method as indicated above.

DESCRIPTION OF EMBODIMENTS

Certain concepts may be described herein with reference to particular technology fields or standards and/or using language applicable to those fields or standards. For instance, certain embodiments may be described with reference to cells, subframes/slots, channels, etc. as understood in the context of LTE, or with reference to beams, slots/mini-slots, channels, etc. as understood in the context of 3GPP NR. Nevertheless, unless otherwise indicated, the described concepts may be more generally applicable and are not to be limited according to any such field, standard, language, etc.

InFIG. 3, network node160includes processing circuitry170, device readable medium180, interface190, auxiliary equipment184, power source186, power circuitry187, and antenna162. Although network node160illustrated in the example wireless network ofFIG. 1may represent a device that includes the illustrated combination of hardware components, other embodiments may comprise network nodes with different combinations of components. It is to be understood that a network node comprises any suitable combination of hardware and/or software needed to perform the tasks, features, functions and methods disclosed herein. Moreover, while the components of network node160are depicted as single boxes located within a larger box, or nested within multiple boxes, in practice, a network node may comprise multiple different physical components that make up a single illustrated component (e.g., device readable medium180may comprise multiple separate hard drives as well as multiple RAM modules).

Processing circuitry170may comprise a combination of one or more of a microprocessor, controller, microcontroller, central processing unit, digital signal processor, application-specific integrated circuit, field programmable gate array, or any other suitable computing device, resource, or combination of hardware, software and/or encoded logic operable to provide, either alone or in conjunction with other network node160components, such as device readable medium180, network node160functionality. For example, processing circuitry170may execute instructions stored in device readable medium180or in memory within processing circuitry170. Such functionality may include providing any of the various wireless features, functions, or benefits discussed herein. In some embodiments, processing circuitry170may include a system on a chip (SOC).

Interface190is used in the wired or wireless communication of signalling and/or data between network node160, network106, and/or WDs110. As illustrated, interface190comprises port(s)/terminal(s)194to send and receive data, for example to and from network106over a wired connection. Interface190also includes radio front end circuitry192that may be coupled to, or in certain embodiments a part of, antenna162. Radio front end circuitry192comprises filters198and amplifiers196. Radio front end circuitry192may be connected to antenna162and processing circuitry170. Radio front end circuitry may be configured to condition signals communicated between antenna162and processing circuitry170. Radio front end circuitry192may receive digital data that is to be sent out to other network nodes or WDs via a wireless connection. Radio front end circuitry192may convert the digital data into a radio signal having the appropriate channel and bandwidth parameters using a combination of filters198and/or amplifiers196. The radio signal may then be transmitted via antenna162. Similarly, when receiving data, antenna162may collect radio signals which are then converted into digital data by radio front end circuitry192. The digital data may be passed to processing circuitry170. In other embodiments, the interface may comprise different components and/or different combinations of components.

Power circuitry187may comprise, or be coupled to, power management circuitry and is configured to supply the components of network node160with power for performing the functionality described herein. Power circuitry187may receive power from power source186. Power source186and/or power circuitry187may be configured to provide power to the various components of network node160in a form suitable for the respective components (e.g., at a voltage and current level needed for each respective component). Power source186may either be included in, or external to, power circuitry187and/or network node160. For example, network node160may be connectable to an external power source (e.g., an electricity outlet) via an input circuitry or interface such as an electrical cable, whereby the external power source supplies power to power circuitry187. As a further example, power source186may comprise a source of power in the form of a battery or battery pack which is connected to, or integrated in, power circuitry187. The battery may provide backup power should the external power source fail. Other types of power sources, such as photovoltaic devices, may also be used.

Antenna111may include one or more antennas or antenna arrays, configured to send and/or receive wireless signals, and is connected to interface114. In certain alternative embodiments, antenna111may be separate from WD110and be connectable to WD110through an interface or port. Antenna111, interface114, and/or processing circuitry120may be configured to perform any receiving or transmitting operations described herein as being performed by a WD. Any information, data and/or signals may be received from a network node and/or another WD. In some embodiments, radio front end circuitry and/or antenna111may be considered an interface.

As illustrated, interface114comprises radio front end circuitry112and antenna111. Radio front end circuitry112comprise one or more filters118and amplifiers116. Radio front end circuitry114is connected to antenna111and processing circuitry120, and is configured to condition signals communicated between antenna111and processing circuitry120. Radio front end circuitry112may be coupled to or a part of antenna111. In some embodiments, WD110may not include separate radio front end circuitry112; rather, processing circuitry120may comprise radio front end circuitry and may be connected to antenna111. Similarly, in some embodiments, some or all of RF transceiver circuitry122may be considered a part of interface114. Radio front end circuitry112may receive digital data that is to be sent out to other network nodes or WDs via a wireless connection. Radio front end circuitry112may convert the digital data into a radio signal having the appropriate channel and bandwidth parameters using a combination of filters118and/or amplifiers116. The radio signal may then be transmitted via antenna111. Similarly, when receiving data, antenna111may collect radio signals which are then converted into digital data by radio front end circuitry112. The digital data may be passed to processing circuitry120. In other embodiments, the interface may comprise different components and/or different combinations of components.

As illustrated, processing circuitry120includes one or more of RF transceiver circuitry122, baseband processing circuitry124, and application processing circuitry126. In other embodiments, the processing circuitry may comprise different components and/or different combinations of components. In certain embodiments processing circuitry120of WD110may comprise a SOC. In some embodiments, RF transceiver circuitry122, baseband processing circuitry124, and application processing circuitry126may be on separate chips or sets of chips. In alternative embodiments, part or all of baseband processing circuitry124and application processing circuitry126may be combined into one chip or set of chips, and RF transceiver circuitry122may be on a separate chip or set of chips. In still alternative embodiments, part or all of RF transceiver circuitry122and baseband processing circuitry124may be on the same chip or set of chips, and application processing circuitry126may be on a separate chip or set of chips. In yet other alternative embodiments, part or all of RF transceiver circuitry122, baseband processing circuitry124, and application processing circuitry126may be combined in the same chip or set of chips. In some embodiments, RF transceiver circuitry122may be a part of interface114. RF transceiver circuitry122may condition RF signals for processing circuitry120.

Processing circuitry120may be configured to perform any determining, calculating, or similar operations (e.g., certain obtaining operations) described herein as being performed by a WD. These operations, as performed by processing circuitry120, may include processing information obtained by processing circuitry120by, for example, converting the obtained information into other information, comparing the obtained information or converted information to information stored by WD110, and/or performing one or more operations based on the obtained information or converted information, and as a result of said processing making a determination.

User interface equipment132may provide components that allow for a human user to interact with WD110. Such interaction may be of many forms, such as visual, audial, tactile, etc. User interface equipment132may be operable to produce output to the user and to allow the user to provide input to WD110. The type of interaction may vary depending on the type of user interface equipment132installed in WD110. For example, if WD110is a smart phone, the interaction may be via a touch screen; if WD110is a smart meter, the interaction may be through a screen that provides usage (e.g., the number of gallons used) or a speaker that provides an audible alert (e.g., if smoke is detected). User interface equipment132may include input interfaces, devices and circuits, and output interfaces, devices and circuits. User interface equipment132is configured to allow input of information into WD110, and is connected to processing circuitry120to allow processing circuitry120to process the input information. User interface equipment132may include, for example, a microphone, a proximity or other sensor, keys/buttons, a touch display, one or more cameras, a USB port, or other input circuitry. User interface equipment132is also configured to allow output of information from WD110, and to allow processing circuitry120to output information from WD110. User interface equipment132may include, for example, a speaker, a display, vibrating circuitry, a USB port, a headphone interface, or other output circuitry. Using one or more input and output interfaces, devices, and circuits, of user interface equipment132, WD110may communicate with end users and/or the wireless network, and allow them to benefit from the functionality described herein.

Auxiliary equipment134is operable to provide more specific functionality which may not be generally performed by WDs. This may comprise specialized sensors for doing measurements for various purposes, interfaces for additional types of communication such as wired communications etc. The inclusion and type of components of auxiliary equipment134may vary depending on the embodiment and/or scenario.

Power source136may, in some embodiments, be in the form of a battery or battery pack. Other types of power sources, such as an external power source (e.g., an electricity outlet), photovoltaic devices or power cells, may also be used. WD110may further comprise power circuitry137for delivering power from power source136to the various parts of WD110which need power from power source136to carry out any functionality described or indicated herein. Power circuitry137may in certain embodiments comprise power management circuitry. Power circuitry137may additionally or alternatively be operable to receive power from an external power source; in which case WD110may be connectable to the external power source (such as an electricity outlet) via input circuitry or an interface such as an electrical power cable. Power circuitry137may also in certain embodiments be operable to deliver power from an external power source to power source136. This may be, for example, for the charging of power source136. Power circuitry137may perform any formatting, converting, or other modification to the power from power source136to make the power suitable for the respective components of WD110to which power is supplied.

RAM217may be configured to interface via bus202to processing circuitry201to provide storage or caching of data or computer instructions during the execution of software programs such as the operating system, application programs, and device drivers. ROM219may be configured to provide computer instructions or data to processing circuitry201. For example, ROM219may be configured to store invariant low-level system code or data for basic system functions such as basic input and output (I/O), startup, or reception of keystrokes from a keyboard that are stored in a non-volatile memory. Storage medium221may be configured to include memory such as RAM, ROM, programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), magnetic disks, optical disks, floppy disks, hard disks, removable cartridges, or flash drives. In one example, storage medium221may be configured to include operating system223, application program225such as a web browser application, a widget or gadget engine or another application, and data file227. Storage medium221may store, for use by UE200, any of a variety of various operating systems or combinations of operating systems.

InFIG. 4, processing circuitry201may be configured to communicate with network243busing communication subsystem231. Network243aand network243bmay be the same network or networks or different network or networks. Communication subsystem231may be configured to include one or more transceivers used to communicate with network243b. For example, communication subsystem231may be configured to include one or more transceivers used to communicate with one or more remote transceivers of another device capable of wireless communication such as another WD, UE, or base station of a radio access network (RAN) according to one or more communication protocols, such as IEEE 802.2, CDMA, WCDMA, GSM, LTE, UTRAN, WiMax, or the like. Each transceiver may include transmitter233and/or receiver235to implement transmitter or receiver functionality, respectively, appropriate to the RAN links (e.g., frequency allocations and the like). Further, transmitter233and receiver235of each transceiver may share circuit components, software or firmware, or alternatively may be implemented separately.

The functions may be implemented by one or more applications320(which may alternatively be called software instances, virtual appliances, network functions, virtual nodes, virtual network functions, etc.) operative to implement some of the features, functions, and/or benefits of some of the embodiments disclosed herein. Applications320are run in virtualization environment500which provides hardware330comprising processing circuitry360and memory390. Memory390contains instructions395executable by processing circuitry360whereby application320is operative to provide one or more of the features, benefits, and/or functions disclosed herein.

In some embodiments, some signalling can be effected with the use of control system3230which may alternatively be used for communication between the hardware nodes330and radio units3200.

Referring toFIG. 6, in accordance with an embodiment, a communication system includes telecommunication network410, such as a 3GPP-type cellular network, which comprises access network411, such as a radio access network, and core network414. Access network411comprises a plurality of base stations412a,412b,412c, such as NBs, eNBs, gNBs or other types of wireless access points, each defining a corresponding coverage area413a,413b,413c. Each base station412a,412b,412cis connectable to core network414over a wired or wireless connection415. A first UE491located in coverage area413cis configured to wirelessly connect to, or be paged by, the corresponding base station412c. A second UE492in coverage area413ais wirelessly connectable to the corresponding base station412a. While a plurality of UEs491,492are illustrated in this example, the disclosed embodiments are equally applicable to a situation where a sole UE is in the coverage area or where a sole UE is connecting to the corresponding base station412.

Communication system500further includes base station520provided in a telecommunication system and comprising hardware525enabling it to communicate with host computer510and with UE530. Hardware525may include communication interface526for setting up and maintaining a wired or wireless connection with an interface of a different communication device of communication system700, as well as radio interface527for setting up and maintaining at least wireless connection570with UE530located in a coverage area (not shown inFIG. 7) served by base station520. Communication interface526may be configured to facilitate connection560to host computer510. Connection560may be direct or it may pass through a core network (not shown inFIG. 7) of the telecommunication system and/or through one or more intermediate networks outside the telecommunication system. In the embodiment shown, hardware525of base station520further includes processing circuitry528, which may comprise one or more programmable processors, application-specific integrated circuits, field programmable gate arrays or combinations of these (not shown) adapted to execute instructions. Base station520further has software521stored internally or accessible via an external connection.

It is noted that host computer510, base station520and UE530illustrated inFIG. 7may be similar or identical to host computer430, one of base stations412a,412b,412cand one of UEs491,492ofFIG. 6, respectively. This is to say, the inner workings of these entities may be as shown inFIG. 7and independently, the surrounding network topology may be that ofFIG. 6.

Wireless connection570between UE530and base station520is in accordance with the teachings of the embodiments described throughout this disclosure. One or more of the various embodiments improve the performance of OTT services provided to UE530using OTT connection550, in which wireless connection570forms the last segment.

FIG. 11is a flowchart illustrating a method implemented in a communication system, in accordance with one embodiment. The communication system includes a host computer, a base station and a UE which may be those described with reference toFIGS. 6 and 7. For simplicity of the present disclosure, only drawing references toFIG. 11will be included in this section. In step910(which may be optional), in accordance with the teachings of the embodiments described throughout this disclosure, the base station receives user data from the UE. In step920(which may be optional), the base station initiates transmission of the received user data to the host computer. In step930(which may be optional), the host computer receives the user data carried in the transmission initiated by the base station.

FIG. 12illustrates a method1200in a wireless device according to some embodiments.

Referring toFIG. 12, the method comprises receiving downlink control information (DCI) from a network node (S1205), determining a physical downlink shared channel (PDSCH) group based on information in the received DCI (S1210), and transmitting a hybrid automatic hybrid automatic repeat request acknowledgement (HARQ-ACK) report to the network node based on the determined PDSCH group (S1215).

In certain related embodiments, corresponding operations may be performed in a network node (e.g. a gNB), such as assigning or determining PDSCH groups, transmitting the DCI, and receiving and processing HARQ-ACK report accordingly.

FIG. 13illustrates a method1300in a wireless device according to some other embodiments.

Referring toFIG. 13, the method comprises receiving, from a network node, a trigger for a hybrid automatic repeat request acknowledgement (HARQ-ACK) report (S1305), and in response to the trigger, transmitting, to the network node, the HARQ-ACK report, wherein the HARQ-ACK report comprises a new data indicator (NDI) value for a latest received physical downlink shared channel (PDSCH), along with HARQ feedback for the latest received PDSCH (S1310).

In certain related embodiments, corresponding operations may be performed in a network node (e.g. a gNB), such as assigning or determining PDSCH groups, transmitting the trigger, and receiving and processing HARQ-ACK report accordingly.

In the description that follows, certain embodiments are described in relation to PDSCH groups or PDSCH grouping functionality. In general, a PDSCH group is a set of PDSCHs that for which HARQ feedback is transmitted in some joint form, typically in the same PUCCH resource or slot. Similarly, PDSCH grouping is any process or act that results in multiple PDSCHs being assigned or identified in relation to different PDSCH groups. For instance, PDSCH grouping may be performed by signalling that assigns or identifies different PDSCHs to the same or different PDSCH groups. Such signalling may include, for instance, DCI that schedules or otherwise identifies a PUSCH and allocates and/or identifies a PUCCH resources to carry HARQ feedback for the PUSCH. The same DCI can also associate the PUSCH with a PDSCH group, or the PUSCH may become part of a PDSCH group through assignment to the same PUCCH resource as other PUSCHs. The HARQ feedback for a PDSCH group may be transmitted to a network node as a group or collection of bits, where different bits in the group or collection correspond to HARQ feedback for different PUSCHs. The group or collection of bits may be referred to as a HARQ codebook. The use of PDSCH grouping may provide certain potential benefits, such as allowing a wireless device or network node to perform certain actions in relation to an entire group, such as requesting feedback or performing some analysis for an entire group.

In general, the described embodiments may be performed, in whole or in part, in either licensed or unlicensed spectrum. For instance, any of the described control and/or data signalling may be performed in either uplink licensed or unlicensed spectrum, and uplink and/or downlink signalling may be performed in either uplink licensed or unlicensed spectrum. Certain embodiments, for instance, may be implemented in a standalone NR-U system in which communication is performed without accessing licensed spectrum.

In certain embodiments, explicit PDSCH grouping functionality is enabled or disabled via RRC. In such embodiments, the presence or absence of a PDSCH group index field in DCI may depend on an RRC configuration. The RRC configuration may indicate, e.g., one or more of the following:If the PDSCH grouping functionality is enabled or notMaximum number of PDSCH groups.The maximum number of PDSCH per groupIf reset indicator that signals new HARQ-ACK feedback for a PDSCH group is enabled or not

If PDSCH grouping is enabled via RRC, the DCI may include one or more of the following:PDSCH group index field: x bits where x=ceil[log 2(Maximum number of PDSCH groups)].Reset or request indicator that signals new HARQ-ACK feedback. One of the following options is usedA bit map of PDSCH groups configured on that cell with a corresponding bit mapped to each group. Number of bits=Maximum number of PDSCH groups.For instance,a bit corresponding to a certain HARQ process group set to specific value (0 or 1) indicates to the UE to retransmit/reset the HARQ feedback of the associated group. The bitmap may also encompass the PDSCH groups configured on multiple DL cells.a bit corresponding to a certain HARQ process group set toggled to indicate to the UE that the HARQ feedback of the associated group was correctly received. The bitmap may also encompass the PDSCH groups configured on multiple DL cells.A bit corresponding to the PDSCH group indicated in the DCI.

If the Maximum number of PDSCH groups is set to one, a PDSCH group index field may be omitted or not indicated in the DCI. The Reset/request indicator field typically comprises a single bit.

In certain embodiments, the number of HARQ feedback groups is configured via higher layer signalling, e.g. RRC layer configuration. In some of these embodiments, the size of each HARQ feedback group is fixed via higher layer signalling. One potential benefit of this grouping is the fixed group size. If the UE had previously missed one or more scheduling PDCCH, the HARQ-ACK feedback group size according to the present teaching will not be affected or miscalculated. Also in some of these embodiments, no additional group index is added to the DCI.

In some embodiments, the group is determined by a prefix of the HARQ process ID that is already present in the current DCI. As an example, if the UE is configured by the network to use two HARQ-ACK feedback groups, the HARQ processes with IDs that has 0 in the first bit belong to HARQ-ACK feedback group 0 and those with IDs that has 1 in the first bit belong to HARQ-ACK feedback group 1. More explicitly, if there are 16 HARQ processes, HARQ-ACK feedback group 0 contains HARQ processes #0, #1, . . . , #7, and HARQ-ACK feedback group 1 contains HARQ processes #8, #9, . . . , #15. As another example, if the UE is configured by the network to use four HARQ-ACK feedback groups, the HARQ processes are separated into four HARQ-ACK feedback groups based on the first two bits in the HARQ process IDs.

In some other embodiments, the group is determined by a postfix of the HARQ process ID that is already present in the current DCI. That is, the grouping of HARQ processes is based on the last few bits of the HARQ process IDs.

In still other embodiments, the higher layer signalling directly enumerates the HARQ process IDs for each HARQ-ACK feedback group. For example, the higher layer signalling can configure three HARQ-ACK feedback groups as: group 0 contains five HARQ processes with ID #0, #1, . . . , #4; group 1 contains five HARQ processes with #5, #6, . . . , #9; group 2 contains six HARQ processes with ID #10, #11, . . . , #15.

The higher layer signalling may also configure HARQ-ACK feedback groups with different numbers of HARQ processes in different groups, e.g. configuring group 0 to contain HARQ processes 0, 1 and 2 and group 1 to contain HARQ processes 3 and 4, or configuring group 0 to contain HARQ processes 0, 1 and 2 and group 1 to contain HARQ processes 3, 4, 5, 6 and 7. In cases where the number of HARQ processes is not evenly divisible by the number of HARQ-ACK feedback groups, a procedural rule could be specified to indicate a default number of HARQ processes in each HARQ-ACK feedback group. For instance, as first step, the sizes of all HARQ-ACK feedback groups are set to nrofHARQ-Processes //nrOfHARQ-ACK-feedbackGroups, where “II” indicates integer division (an equivalent denotation is “floor(nrofHARQ-Processes/nrOfHARQ-ACK-feedbackGroups)”). Then, in a second step, 1 is added sequentially to the size of HARQ-ACK feedback group 0, 1, 2 etc., until the sum of the sizes of the HARQ-ACK feedback group equals the number of HARQ processes.

In certain alternative embodiments, in response to a HARQ feedback request, the UE generates and reports the HARQ feedback for the specified PDSCH group(s).

If the HARQ feedback indicator is conveyed in a DL data assignment DCI which includes a PDSCH-to-HARQ-timing-indicator and a PUCCH resource indicator for the HARQ feedback transmission for the PDSCH being scheduled, the requested HARQ feedback for the specified PDSCH group(s) can be jointly encoded together with the HARQ feedback for the new PDSCH being scheduled and transmitted with specified timing and PUCCH resource.

If the HARQ feedback indicator is conveyed in a UL data grant DCI which schedules a PUSCH to be transmitted shortly afterwards, the requested HARQ feedback for the specified PDSCH group(s) can be multiplexed with the UL-SCH data and transmitted in the PUSCH transmission by means of UCI on PUSCH.

If the HARQ feedback indicator is conveyed in a DCI that doesn't schedule any PDSCH or PUSCH transmission, then the timing and resource for the request HARQ feedback transmission is expected to be included in the DCI, and the request HARQ feedback should be transmitted with that timing and resource.

The following description presents certain embodiments in which HARQ-ACK reports are generated in response to a one-shot trigger. In the description that follows, the term “all processes” or “every process” refers to certain HARQ processes that the network requests of the UE. For instance, where no specific HARQ-ACK feedback group is configured, “all processes” refers to all available HARQ processes. Alternatively, where at least one HARQ-ACK feedback group is requested by the network, “all processes” refers to all the HARQ processes belonging to said at least one HARQ-ACK feedback group.

In some embodiments, in response to a UE receiving a trigger for a HARQ-ACK report, for every HARQ process to be reported, the UE reports the corresponding latest NDI value for a latest received PDSCH for that HARQ process along with the corresponding HARQ-ACK for the received PDSCH.

In some embodiments, HARQ-ACK reporting may be performed as follows when a UE reports the latest NDI and HARQ-ACK for a HARQ process ID.If the UE receives a retransmission of HARQ process h, it will reportHARQ-ACK for process h after soft combining with latest PDSCHIf the UE misses a retransmission of HARQ process h, it will reportHARQ-ACK for process h based on previous received PDSCH(s)If a UE receives a new transmission of HARQ process h, it will reportHARQ-ACK for process h based on this PDSCHIf a UE misses a new transmission of HARQ process h, it will reportHARQ-ACK for process h based on previous received PDSCH(s)

If the NDI value matches the last transmitted value, the gNB assumes that the reported HARQ-ACK feedback correctly corresponds to process h. Otherwise, the gNB discards the reported HARQ-ACK feedback and assumes HARQ-ACK for process h is NACK.

In certain embodiments, the trigger indicates a subset of the HARQ processes to be reported. The report for any HARQ process in this set includes the corresponding latest NDI value for a latest received PDSCH for that HARQ process along with the corresponding HARQ-ACK for the received PDSCH.

In some embodiments, HARQ-ACK reporting may be performed as follows when a UE reports the latest NDI and HARQ-ACK for a HARQ process ID.

If the NDI value matches the last received value, the UE reports:If the UE received a retransmission of HARQ process h, it will reportHARQ-ACK for process h after soft combining with PDSCH(s) scheduled using the same NDI value.If the UE misses a retransmission of HARQ process h, it will reportHARQ-ACK for process h based on previous received PDSCH(s)If a UE receives a new transmission of HARQ process h, it will reportHARQ-ACK for process h based on this PDSCHIf a UE misses a new transmission of HARQ process h, it will reportHARQ-ACK for process h based on previous received PDSCH(s)

If the NDI value does not match the latest received value, the UE discard the pending HARQ-ACK for process h (if there is any) and sends a NACK.

The UE reports 2*H HARQ-ACK bits for the H HARQ processes. The codebook is composed of H×2 array with entry (h, b) corresponding to HARQ process h and NDI value b, where h=0, 1, . . . , H−1 and b=0, 1.For a HARQ process h with the NDI value of b in the last received scheduling PDCCH, the UEreports the HARQ-ACK for process h in entry (h, b);and sets the entry (h, 1−b) to NACK.

In certain alternative embodiments, after correctly receiving the feedback in response of one-shot trigger, a network node (e.g., gNB) updates the reset or request indicator for all reported PDSCH groups.

The DAI value for PDSCH groups with a received report for their corresponding HARQ process IDs, are reset to the corresponding initial value in addition to counting the PDSCH of that group that were not reported due to feedback timing that does not meet the required processing time.

In certain alternative embodiments, the timing and resources for a one-shot report have certain characteristics as described below. The UE may include the latest HARQ-ACK status for all received HARQ processes irrespective of the PDSCH-to-HARQ-timing-indicator indicated in the PDSCH scheduling grant as long as the processing time requirements are met.

The timing indication in the one-shot trigger (t1) overrides the one indicated in the PDSCH-to-HARQ-timing-indicator of the PDSCH scheduling DCI (t2), if the absolute timing corresponding to t2 is larger than the absolute timing corresponding to t1, under the condition that the processing time requirements are met.

The one-shot trigger can be included in a DL grant, for example in DCI format 1_0 or 1_1. In this case, the one shot-report is carried by a PUCCH resource in a slot. The slot for transmission of the PUCCH carrying the report, is determined by the PDSCH-to-HARQ-timing-indicator field in the DCI similarly to Rel-15. In one example, the size of the report i.e. the number of NDI and HARQ-ACK bits, determines the PUCCH resource set and the PUCCH resource indicator field in the DCI determines the PUCCH resource to be used for transmission in that set similar to Rel-15. In another example, a UE can be configured by higher layer with a PUCCH resource for one-shot reporting.

The one-shot trigger can be included in a UL grant, for example in DCI format 0_0 or 0_1. In one example, for PUSCH with UL-SCH, the multiplexing procedures for HARQ-ACK on PUSCH similar to those in Rel-15 are used to multiplex the report with UL-SCH on PUSCH. In case of PUSCH without UL-SCH (with or without CSI), the report is considered as HARQ-ACK UCI and multiplexed on PUSCH where in absence of CSI, only the report containing HARQ-ACK information is transmitted on PUSCH, following the mapping rules for HARQ-ACK transmission on PUSCH.

In certain alternative embodiments, the following concepts may apply to encoding a one-shot trigger for all or subset of the HARQ processes in the fallback DCI format.

In one alternative, DCI format 1_0 is used to schedule PDSCH and for sending user plane data is scrambled by C-RNTI or CS-RNTI or MCS-C-RNTI. In this embodiment, a one-shot trigger for all or subset of the HARQ processes is included in DCI format 1_0 without increasing the size of DCI format 1_0. To achieve this, the UL/SUL indicator is used to indicate the one-shot trigger since the use of the UL/SUL indicator is not envisioned to be needed in many scenarios where the one-shot trigger would be useful. The UE is configured with this bit as a one-shot trigger by higher layers in ServingCellConfig when the configuration for the cell is received by the UE.

In another alternative, one of the reserved bits in DCI format 1_0 is used to indicate the one-shot trigger.

In yet another alternative, DCI format 1_0 is used to signal one-shot trigger by setting some of the fields to a special value (i.e. validation bits). The DCI format 1_0 is used to trigger one-shot trigger feedback without scheduling PDSCH.

In the above embodiments, certain communications may be performed in part or in whole in unlicensed spectrum, e.g.,

While the disclosed subject matter has been presented above with reference to various embodiments, it will be understood that various changes in form and details may be made to the described embodiments without departing from the overall scope of the disclosed subject matter.