Hybrid automatic repeat request feedback retransmission

Certain aspects of the present disclosure provide techniques and apparatus for hybrid automatic repeat request (HARQ) feedback retransmission. An example method of wireless communication by a user equipment generally includes receiving signaling indicating to reschedule HARQ feedback for transmission; determining the HARQ feedback based at least in part on one or more fields of the signaling; and transmitting the HARQ feedback based on the determination.

INTRODUCTION

Aspects of the present disclosure relate to wireless communications, and more particularly, to techniques for communicating hybrid automatic repeat request (HARQ) feedback.

Wireless communication systems are widely deployed to provide various telecommunication services such as telephony, video, data, messaging, broadcasts, or other similar types of services. These wireless communication systems may employ multiple-access technologies capable of supporting communication with multiple users by sharing available system resources with those users (e.g., bandwidth, transmit power, or other resources). Multiple-access technologies can rely on any of code division, time division, frequency division orthogonal frequency division, single-carrier frequency division, or time division synchronous code division, to name a few. These and other multiple access technologies have been adopted in various telecommunication standards to provide a common protocol that enables different wireless devices to communicate on a municipal, national, regional, and even global level.

Although wireless communication systems have made great technological advancements over many years, challenges still exist. For example, complex and dynamic environments can still attenuate or block signals between wireless transmitters and wireless receivers, undermining various established wireless channel measuring and reporting mechanisms, which are used to manage and optimize the use of finite wireless channel resources. Consequently, there exists a need for further improvements in wireless communications systems to overcome various challenges.

SUMMARY

One aspect provides an example method of wireless communication by a user equipment (UE). The method generally includes receiving signaling indicating to reschedule hybrid automatic repeat request (HARQ) feedback for transmission; determining the HARQ feedback based at least in part on one or more fields of the signaling; and transmitting the HARQ feedback based on the determination.

One aspect provides an example method of wireless communication by a network entity. The method generally includes sending, to a user equipment (UE), signaling indicating to reschedule hybrid automatic repeat request (HARQ) feedback for transmission, wherein the signaling identifies the HARQ feedback based at least in part on one or more fields of the signaling; and obtaining the HARQ feedback in response to the signaling.

Other aspects provide: an apparatus operable, configured, or otherwise adapted to perform the aforementioned methods as well as those described elsewhere herein; a non-transitory, computer-readable media comprising instructions that, when executed by one or more processors of an apparatus, cause the apparatus to perform the aforementioned methods as well as those described elsewhere herein; a computer program product embodied on a computer-readable storage medium comprising code for performing the aforementioned methods as well as those described elsewhere herein; and an apparatus comprising means for performing the aforementioned methods as well as those described elsewhere herein. By way of example, an apparatus may comprise a processing system, a device with a processing system, or processing systems cooperating over one or more networks.

DETAILED DESCRIPTION

Aspects of the present disclosure provide apparatuses, methods, processing systems, and computer-readable mediums for a hybrid automatic repeat request (HARQ) feedback retransmission.

Certain wireless communication networks (e.g., 5G New Radio (NR) systems) may use radio network temporary identifiers (RNTIs) to scramble certain control signaling for a specific user equipment (UE) or a group of UEs. RNTIs may be used for scrambling control signaling for specific types of information, such as system information, transmit power controls, and/or configured scheduling, such as semi-persistent scheduling. Certain wireless communication networks (e.g., 5G NR systems) may support transmission of data with HARQ to enable forward error correction at the receiver in addition to automatic re-transmission of corrupted data at a receiver. A transmitter (e.g., a base station) may send an initial transmission of data to a receiver (e.g., a UE), and if the data is corrupted at the receiver, the transmitter may send one or more retransmissions of the data. The receiver may send, to the transmitter, HARQ feedback to indicate whether a transmission was successfully decoded.

In certain cases, control signaling (e.g., downlink control information (DCI)) may have a cyclic redundancy check (CRC) scrambled with a specific RNTI, such as a cell random network identifier (C-RNTI) or a configured scheduling RNTI (CS-RNTI). If the CRC is scrambled with a certain RNTI, a particular field in the control signaling may be designated for indicating certain information, such as a modulation and coding scheme, an indication of the HARQ feedback to retransmit, or an indication of secondary cell dormancy. In some cases, there may be ambiguity as to the meaning of the field when the control signaling triggers a retransmission of HARQ feedback with certain RNTIs.

Aspects of the present disclosure provide methods and apparatus for indicating a HARQ feedback retransmission. For example, the DCI triggering the HARQ feedback retransmission may have a CRC scrambled with a C-RNTI. In such cases, a specific field (e.g., a modulation and coding scheme field associated with transport block 1) in the triggering DCI may be interpreted as a HARQ feedback retransmission offset (as further described herein with respect toFIG.4), if the DCI indicates to transmit a HARQ feedback retransmission. In some cases, the DCI triggering the HARQ feedback retransmission may have a CRC scrambled with a CS-RNTI. In such cases, the triggering DCI may be allowed or not allowed to indicate release of semi-persistent scheduling for downlink transmission(s) or configured grant for uplink transmission.

The HARQ feedback retransmission described herein may enable improved wireless communication performance, for example, lower latencies and/or higher throughput. For example, a HARQ feedback retransmission may enable a network to prioritize other communications (e.g., URLLC) over receiving certain HARQ feedback and dynamically request the HARQ feedback retransmission.

Introduction to Wireless Communication Networks

FIG.1depicts an example of a wireless communication network100, in which aspects described herein may be implemented.

Generally, wireless communication network100includes base stations (BSs)102, user equipments (UEs)104, one or more core networks, such as an Evolved Packet Core (EPC) 160 and 5G Core (5GC) network190, which interoperate to provide wireless communications services.

BSs102may provide an access point to the EPC160and/or 5GC190for a UE104, and may perform one or more of the following functions: transfer of user data, radio channel ciphering and deciphering, integrity protection, header compression, mobility control functions (e.g., handover, dual connectivity), inter-cell interference coordination, connection setup and release, load balancing, distribution for non-access stratum (NAS) messages, NAS node selection, synchronization, radio access network (RAN) sharing, multimedia broadcast multicast service (MBMS), subscriber and equipment trace, RAN information management (RIM), paging, positioning, delivery of warning messages, among other functions. Base stations may include and/or be referred to as a gNB, NodeB, eNB, ng-eNB (e.g., an eNB that has been enhanced to provide connection to both EPC160and 5GC190), an access point, a base transceiver station, a radio base station, a radio transceiver, or a transceiver function, or a transmission reception point in various contexts.

A base station, such as BS102, may include components that are located at a single physical location or components located at various physical locations. In examples in which the base station includes components that are located at various physical locations, the various components may each perform various functions such that, collectively, the various components achieve functionality that is similar to a base station that is located at a single physical location. As such, a base station may equivalently refer to a standalone base station or a base station including components that are located at various physical locations or virtualized locations. In some implementations, a base station including components that are located at various physical locations may be referred to as or may be associated with a disaggregated radio access network (RAN) architecture, such as an Open RAN (O-RAN) or Virtualized RAN (VRAN) architecture. In some implementations, such components of a base station may include or refer to one or more of a central unit (CU), a distributed unit (DU), or a radio unit (RU).

BSs102wirelessly communicate with UEs104via communications links120. Each of BSs102may provide communication coverage for a respective geographic coverage area110, which may overlap in some cases. For example, small cell102′ (e.g., a low-power base station) may have a coverage area110′ that overlaps the coverage area110of one or more macrocells (e.g., high-power base stations).

The communication links120between BSs102and UEs104may include uplink (UL) (also referred to as reverse link) transmissions from a UE104to a BS102and/or downlink (DL) (also referred to as forward link) transmissions from a BS102to a UE104. The communication links120may use multiple-input and multiple-output (MIMO) antenna technology, including spatial multiplexing, beamforming, and/or transmit diversity in various aspects.

Examples of UEs104include a cellular phone, a smart phone, a session initiation protocol (SIP) phone, a laptop, a personal digital assistant (PDA), a satellite radio, a global positioning system, a multimedia device, a video device, a digital audio player, a camera, a game console, a tablet, a smart device, a wearable device, a vehicle, an electric meter, a gas pump, a large or small kitchen appliance, a healthcare device, an implant, a sensor/actuator, a display, or other similar devices. Some of UEs104may be internet of things (IoT) devices (e.g., parking meter, gas pump, toaster, vehicles, heart monitor, or other IoT devices), always on (AON) devices, or edge processing devices. UEs104may also be referred to more generally as a station, a mobile station, a subscriber station, a mobile unit, a subscriber unit, a wireless unit, a remote unit, a mobile device, a wireless device, a wireless communications device, a remote device, a mobile subscriber station, an access terminal, a mobile terminal, a wireless terminal, a remote terminal, a handset, a user agent, a mobile client, or a client.

Communications using higher frequency bands may have higher path loss and a shorter range compared to lower frequency communications. Accordingly, certain base stations (e.g.,180inFIG.1) may utilize beamforming182with a UE104to improve path loss and range. For example, base station180and the UE104may each include a plurality of antennas, such as antenna elements, antenna panels, and/or antenna arrays to facilitate the beamforming.

In some cases, base station180may transmit a beamformed signal to UE104in one or more transmit directions182′. UE104may receive the beamformed signal from the base station180in one or more receive directions182″. UE104may also transmit a beamformed signal to the base station180in one or more transmit directions182″. Base station180may also receive the beamformed signal from UE104in one or more receive directions182′. Base station180and UE104may then perform beam training to determine the best receive and transmit directions for each of base station180and UE104. Notably, the transmit and receive directions for base station180may or may not be the same. Similarly, the transmit and receive directions for UE104may or may not be the same.

Wireless communication network100includes a HARQ feedback retransmission component199, which may be configured to signal an indication to reschedule HARQ feedback for retransmission and receive the HARQ feedback in response to the signaling. Wireless communication network100further includes a HARQ feedback retransmission component198, which may be configured to receive signaling indicating to reschedule HARQ feedback for retransmission and transmit the HARQ feedback.

FIG.2depicts aspects of an example BS102and a UE104. Generally, BS102includes various processors (e.g.,220,230,238, and240), antennas234a-t(collectively234), transceivers232a-t(collectively232), which include modulators and demodulators, and other aspects, which enable wireless transmission of data (e.g., data source212) and wireless reception of data (e.g., data sink239). For example, BS102may send and receive data between itself and UE104.

BS102includes controller/processor240, which may be configured to implement various functions related to wireless communications. In the depicted example, controller/processor240includes a HARQ feedback retransmission component241, which may be representative of the HARQ feedback retransmission component199ofFIG.1. Notably, while depicted as an aspect of controller/processor240, the HARQ feedback retransmission component241may be implemented additionally or alternatively in various other aspects of BS102in other implementations.

Generally, UE104includes various processors (e.g.,258,264,266, and280), antennas252a-r(collectively252), transceivers254a-r(collectively254), which include modulators and demodulators, and other aspects, which enable wireless transmission of data (e.g., data source262) and wireless reception of data (e.g., data sink260).

UE104includes controller/processor280, which may be configured to implement various functions related to wireless communications. In the depicted example, controller/processor280includes a HARQ feedback retransmission component281, which may be representative of the HARQ feedback retransmission component198ofFIG.1. Notably, while depicted as an aspect of controller/processor280, the HARQ feedback retransmission component281may be implemented additionally or alternatively in various other aspects of UE104in other implementations.

While the user equipment104is described with respect toFIGS.1and2as communicating with a base station and/or within a network, the user equipment104may be configured to communicate directly with/transmit directly to another user equipment104, or with/to another wireless device without relaying communications through a network. In some aspects, the base station102illustrated inFIG.2and described above is an example of another user equipment104, or vice versa.

FIGS.3A,3B,3C, and3Ddepict aspects of data structures for a wireless communication network, such as wireless communication network100ofFIG.1. In particular,FIG.3Ais a diagram300illustrating an example of a first subframe within a 5G (e.g., 5G NR) frame structure,FIG.3Bis a diagram330illustrating an example of DL channels within a 5G subframe,FIG.3Cis a diagram350illustrating an example of a second subframe within a 5G frame structure, andFIG.3Dis a diagram380illustrating an example of UL channels within a 5G subframe.

Further discussions regardingFIG.1,FIG.2, andFIGS.3A,3B,3C, and3Dare provided later in this disclosure.

Introduction to mmWave Wireless Communications

In wireless communications, an electromagnetic spectrum is often subdivided into various classes, bands, channels, or other features. The subdivision is often provided based on wavelength and frequency, where frequency may also be referred to as a carrier, a subcarrier, a frequency channel, a tone, or a subband.

5G networks may utilize several frequency ranges, which in some cases are defined by a standard, such as the 3GPP standards. For example, 3GPP technical standard TS 38.101 currently defines Frequency Range 1 (FR1) as including 600 MHz-6 GHz, though specific uplink and downlink allocations may fall outside of this general range. Thus, FR1 is often referred to (interchangeably) as a “Sub-6 GHz” band.

Similarly, TS 38.101 currently defines Frequency Range 2 (FR2) as including 26-41 GHz, though again specific uplink and downlink allocations may fall outside of this general range. FR2, is sometimes referred to (interchangeably) as a “millimeter wave” (“mmW” or “mmWave”) band, despite being different from the extremely high frequency (EHF) band (30 GHz-300 GHz) that is identified by the International Telecommunications Union (ITU) as a “millimeter wave” band because wavelengths at these frequencies are between 1 millimeter and 10 millimeters.

Communications using mmWave/near mmWave radio frequency band (e.g., 3 GHz-300 GHz) may have higher path loss and a shorter range compared to lower frequency communications. As described above with respect toFIG.1, a base station (e.g.,180) configured to communicate using mmWave/near mmWave radio frequency bands may utilize beamforming (e.g.,182) with a UE (e.g.,104) to improve path loss and range.

Further, as described herein, HARQ feedback may be communicated in mmWave frequency bands and/or other frequency bands.

Example HARQ Communications

Certain wireless communication networks (e.g., 5G NR systems) may support transmission of data with hybrid automatic repeat request (HARQ) to provide forward error correction at a receiver in addition to automatic re-transmission of corrupted data to the receiver. For example, a transmitter (e.g., the BS102) may send an initial transmission of data to a receiver (e.g., the UE104), and if the data is corrupted at the receiver, the transmitter may send one or more retransmissions of the data (such as a transport block (TB), codeblock group (CBG), or one or more codeblocks) until the data is successfully decoded at the receiver, or the maximum number of retransmissions of the data has occurred, or some other termination condition is encountered.

As re-transmissions are received, the receiver may combine the received transmissions (including the initial transmission and re-transmissions) to attempt to decode the data. In certain cases, the receiver may send, to the transmitter, HARQ feedback to indicate whether a transmission was successfully decoded. The HARQ feedback may include an acknowledgment (ACK) to indicate the data is decoded successfully at the receiver or a negative-ACK (NACK) to indicate the data is decoded in error or unsuccessfully at the receiver. In certain cases, HARQ feedback may also be referred to as HARQ-ACK feedback or a HARQ-ACK codebook. The transmitter may send a re-transmission of the data if a NACK is received and may terminate transmission of the data if an ACK is received. In certain cases, the transmitter may send a re-transmission if the transmitter fails to receive an ACK within a certain period of time. The transmitter may process (e.g., encode and modulate) the data with forward error correction and/or redundancy information, which may be selected such that the data can be decoded successfully with a high probability. The data may also be referred to as a TB, a codeword, a data block, etc. In certain cases, a data transmission (e.g., a transport block) may be segmented into codeblocks (CBs), and re-transmissions may be triggered on a CBG basis (e.g., a group of codeblocks). In other words, a re-transmission may include a portion of the initial transmission, such as a codeblock group of a transport block.

In aspects, HARQ feedback (e.g., an ACK or a NACK) reported by a UE may be formatted according to a codebook. For example, a codebook with respect to HARQ may define the number of HARQ bits to be reported and the order in which certain HARQ information is arranged in the bits. The codebook may define what each HARQ bit represents based on the location of the HARQ bit in the HARQ feedback. For example, a given HARQ bit may correspond to a specific CBG, a specific TB, a specific HARQ process (e.g., HARQ process identifier), a specific carrier, and a specific serving cell. The codebook provides a mapping of the HARQ bit locations in the HARQ feedback to specific HARQ transmissions based on the respective CBG, TB, HARQ process, carrier, and/or serving cell. As used herein, a carrier may refer to a component carrier.

Certain wireless communication systems (e.g., 5G NR systems) may support various HARQ codebooks, such as a Type 1 codebook, a Type 2 codebook, or a Type 3 codebook. In general, the Type 1 codebook may have a fixed size for HARQ feedback associated with a specific time window. The Type 2 codebook may have a dynamic size for HARQ feedback. The Type 3 codebook may be associated with one-shot HARQ-ACK feedback. In certain cases (Release 17 of 3GPP), the Type 3 codebook may provide an enhanced codebook with a smaller size compared to certain releases in 3GPP (e.g., Release 16). The codebook size of a single triggered enhanced Type 3 HARQ-ACK codebook may be at least determined by a radio resource control (RRC) configuration. The enhanced Type 3 HARQ-ACK codebook construction may HARQ processes as a basis (e.g., ordered according to HARQ process IDs and/or serving cells)

In certain cases, a one-shot HARQ-ACK feedback scheme may be employed for the transmitter to request HARQ-ACK feedback on a dynamic basis. For example, a receiver may be configured to refrain from reporting HARQ-ACK feedback, until the transmitter sends a request for HARQ feedback to the receiver. For example, the one-shot HARQ-ACK feedback scheme may be employed when the network is transmitting certain packets without re-transmissions (e.g., in ultra-reliable, low-latency communications (URLLC) applications), and the network may decide when to request HARQ feedback from a UE, for example, when certain network service demands and/or loads (e.g., data rates, latencies, reliability) have lessened. In response to the one-shot HARQ-ACK feedback request, the receiver may send, to the transmitter, the latest status of all of the HARQ processes configured for one or more carriers and/or serving cells. The receiver may send a snapshot of the ACK-NACK information related to the transmission(s) received at the receiver.

Certain wireless communication systems (e.g., 5G NR systems) may support a HARQ feedback retransmission, for example, due to a cancelled HARQ feedback. The network and/or UE may decide to cancel HARQ feedback, for example, in response to higher priority transmissions. In certain cases, the network may decide to cancel HARQ feedback by receiving HARQ feedback from a UE and/or by scheduling other communications in the transmission occasion of the HARQ feedback. The UE may decide to cancel HARQ feedback by performing other communications, for example, transmitting and/or receiving other signals in the transmission the HARQ feedback.

The wireless communication system may support one-shot (e.g., dynamic) triggering (e.g., via downlink control information (DCI) associated with a downlink assignment) of HARQ feedback retransmission on an uplink channel resource (e.g., physical uplink control channel (PUCCH) resource). The HARQ feedback retransmission may be associated with a Type 1 codebook, Type 2 codebook, Type 3 codebook, or an enhancement thereof. The DCI triggering (e.g., via a downlink assignment) the one-shot HARQ-ACK retransmission on a PUCCH resource may dynamically indicate the HARQ-ACK codebook(s) and/or corresponding PUCCH occasions to be re-transmitted.

FIG.4is a timing diagram illustrating an example of a HARQ feedback retransmission at a UE. In this example, the UE may be scheduled to transmit HARQ feedback402in slot n. In certain cases, the HARQ feedback402may identify ACK-NACK information associated with downlink transmissions from the network. For example, the HARQ feedback402may identify a list of one or more HARQ process identifiers (IDs)404as indications of an ACK or a NACK associated with the corresponding HARQ process. In some cases, the network may decide to schedule the HARQ feedback402for a retransmission, for example, due to the HARQ feedback402being canceled at the UE and/or network.

The UE may receive an indication406to transmit a HARQ feedback retransmission in slot m. In some cases, DCI may carry the indication406to trigger the HARQ feedback retransmission. The triggering DCI may dynamically indicate a time offset408indicative of a number of PUCCH slots/sub-slots between the triggering DCI and the PUCCH slot/sub-slot of the HARQ-ACK codebook to be re-transmitted. Such a time offset may be referred to as a HARQ feedback retransmission offset or a HARQ-ACK codebook retransmission offset. The triggering DCI may indicate to transmit the HARQ feedback retransmission in slot/sub-slot m+k and indicate the HARQ feedback retransmission offset. The PUCCH slot/sub-slot n of the HARQ feedback to be retransmitted may be determined according to the following expression:
n=m−HARQ_retx_offset
where HARQ_retx_offset is the time offset408, n is the slot associated with the HARQ feedback, and m is the slot in which the DCI triggering the HARQ feedback retransmission is received. It will be appreciated that usage of slots as a time domain resource unit is merely an example, and other suitable time domain resources units may be used, such as sub-slots, symbols, etc. In the DCI, the time offset408may be indicated as a value of a multi-bit field associated with a range of values. For example, the time offset408may have a value of −7 slots to 24 slots, which may correspond to a five-bit field, where ‘00000’ may represent the lowest value (−7) of the time offset, ‘11111’ may represent the highest value (24) of the time offset, and so on for the values between ‘00000’ and ‘11111’. It will be appreciated that a negative value for the time offset may be indicative of the HARQ feedback402being scheduled in a slot after the triggering DCI (e.g., the DCI carrying the indication406) is received. In certain cases, the range of values for the time offset408supported by a UE may be signalled to the network in a UE capability report. The UE may identify the HARQ feedback402for retransmission based on slot n matching the time position in which the HARQ feedback402was scheduled. The UE may transmit a HARQ feedback retransmission410in slot m+k, where the HARQ feedback retransmission410may carry the same HARQ feedback information as the HARQ feedback402, such as the list of HARQ process IDs404.

Aspects Related to HARQ Feedback Retransmission

Aspects of the present disclosure provide methods and apparatus for indicating a HARQ feedback retransmission. In certain cases, the DCI triggering the HARQ feedback retransmission may have a cyclic redundancy check (CRC) scrambled with a cell random network identifier (C-RNTI). In such cases, a specific field (e.g., a modulation and coding scheme (MCS) field associated with transport block 1) in the triggering DCI may be interpreted as the HARQ feedback retransmission offset, if the DCI indicates to transmit a HARQ feedback retransmission. The C-RNTI may be a UE-specific RNTI to facilitate scheduling of unicast transmissions to the UE, for example. In some cases, the DCI triggering the HARQ feedback retransmission may have a CRC scrambled with a configured scheduling RNTI (CS-RNTI). In such cases, the triggering DCI may be allowed or not allowed to indicate releasing (e.g., deactivation) of semi-persistent scheduling (SPS). The CS-RNTI may be used for activating or releasing periodic transmissions, such as SPS for downlink transmissions and/or a configured grant (CG) for uplink transmissions.

The HARQ feedback retransmission described herein may enable improved wireless communication performance, for example, lower latencies and/or higher throughput. For example, a HARQ feedback retransmission may enable a network to prioritize other communications (e.g., URLLC) over receiving certain HARQ feedback and dynamically request the HARQ feedback retransmission.

FIG.5is a signaling flow diagram illustrating example communications of a HARQ feedback retransmission. At activity502, the UE104may receive, from the BS102, signaling (e.g., DCI) scheduling one or more downlink transmissions as well as PUCCH resources for HARQ feedback associated with the downlink transmission(s).

At activity504, the UE104may receive, from the BS102, the downlink transmission(s) scheduled at activity502. For example, the UE104may receive downlink data from the BS102.

Optionally, at activity506, the UE104may transmit, to the BS102, the HARQ feedback associated with the downlink transmission(s). The HARQ feedback may indicate whether the downlink transmission(s) were successfully decoded at the UE104. As an example, the UE104may be scheduled to transmit the HARQ feedback in slot n, for example, as depicted inFIG.4.

At activity508, the UE104may receive, from the BS102, signaling scheduling a HARQ feedback retransmission associated with the downlink transmission(s). In some cases, the signaling may indicate to reschedule a HARQ feedback transmission yet to be transmitted or previously canceled. In certain cases, the signaling may indicate to retransmit a HARQ feedback transmission. The UE104may receive the signaling scheduling the HARQ feedback retransmission in slot m, for example, as depicted inFIG.4. In some cases, the BS102and/or the UE104may cancel the HARQ feedback scheduled for transmission at activity506. The BS102may decide not to receive the HARQ feedback at activity506, for example, due to other higher priority communications (e.g., URLLC). Additionally, or alternatively, the UE104may decide not to transmit the HARQ feedback at activity506, for example, due to other higher priority communications (e.g., URLLC).

At activity510, the UE104may determine the HARQ feedback for retransmission, for example, based on a time offset indicated in the signaling at activity508. For example, the signaling triggering the HARQ feedback retransmission may identify the HARQ feedback scheduled for transmission in slot n based on the time offset relative to when the signaling triggering the HARQ feedback retransmission is received (slot m), for example, as described herein with respect toFIG.4. The time offset may be indicated as a value of a multi-bit field, such as the MCS field of transport block 1 in DCI, as further described herein with respectFIG.6A.

At activity512, the UE104may transmit, to the BS102, the HARQ feedback retransmission, for example, in slot m+k as depicted inFIG.4. The HARQ feedback may include ACK-NACK states associated with one or more transmission, such as the transmissions received at activity504.

In certain aspects, DCI having a CRC scrambled with a C-RNTI may use the MCS field in transport block 1 to indicate the HARQ feedback retransmission offset or secondary cell dormancy. If the DCI indicates to transmit a HARQ feedback retransmission, the MCS field may be interpreted as indicating the HARQ feedback retransmission offset (e.g., the time offset408). For example, if the DCI field or bit indicating whether to transmit the HARQ feedback retransmission is set to a value (e.g., 1) indicating to retransmit or reschedule the HARQ feedback, the MCS field may be interpreted as indicating the HARQ feedback retransmission offset, for example, as further described herein with respect toFIG.6A. When the C-RNTI is used for CRC scrambling of the DCI triggering the one-shot HARQ feedback retransmission, the DCI field/bit used to indicate to transmit the HARQ feedback retransmission may be set to the value (e.g., 1) indicating to retransmit or reschedule the HARQ feedback to also trigger interpretation of the MCS field as the HARQ feedback retransmission offset. If the DCI field/bit indicating to transmit the HARQ feedback retransmission is set to the complementary value (e.g., 0) or not present, the MCS field may be interpreted as a bitmap indicating the secondary cell dormancy state(s).

For certain aspects, DCI having the CRC scrambled with a CS-RNTI may use the MCS field in transport block 1 to indicate SPS or CG release (or deactivation) or indicate the HARQ feedback retransmission offset. For example, the value of ‘11111’ in the MCS field may be interpreted as releasing (deactivating) SPS or CG. The value of ‘00000’ of the HARQ Process Number field may be interpreted as activating SPS or CG. In certain cases, if the DCI field or bit indicating whether to transmit the HARQ feedback retransmission is set to a value (e.g., 1) indicating to retransmit or reschedule the HARQ feedback, the MCS field may be interpreted as indicating the HARQ feedback retransmission offset and not be allowed to indicate release of SPS or CG.

In some cases, if the DCI field or bit indicating whether to transmit the HARQ feedback retransmission is set to the value (e.g., 1) indicating to retransmit or reschedule the HARQ feedback, the MCS field may be allowed to indicate release of SPS or CG. For example, the MCS value of ‘11111’ may be interpreted as releasing SPS, and the remaining values of the MCS field may be interpreted as indicating the HARQ feedback transmission offset. The UE may be configured with one value removed from the range of values for the HARQ feedback retransmission offset. For example, the UE may be configured to interpret the remaining values of the MCS field as corresponding to the values of −7 slots to 23 slots, where the value 24 is removed from the range of values for the HARQ feedback retransmission offset. In certain cases, other field(s) may be used to indicate the HARQ feedback transmission offset, for example, as further described herein with respect toFIG.6B.

FIG.6Ais a diagram illustrating an example DCI format600A, in accordance with certain aspects of the present disclosure. In this example, the DCI format600A may include a DCI format 1_1 or a DCI format 1_2 used for scheduling of one or multiple physical downlink shared channels (PDSCHs) in a cell. In certain cases, the DCI format(s) 1_1 and/or 1_2 may be used to schedule a HARQ feedback retransmission instead of a downlink transmission. The DCI format600A may include various fields, including, for example, a DCI identifier field, a frequency domain resource assignment (FDRA) field, fields for transport block 1 and/or transport block 2 (including the MCS field, a new data indicator (NDI) field, and a redundancy version field), a HARQ Process Number (HPN) field, a transmit power control (TPC) command field, a PUCCH resource indicator (PRI) field, an antenna ports field, a sounding reference signal (SRS) field, a demodulation reference signal (DMRS) sequence initialization field, and/or a HARQ feedback retransmission indicator field (which may also be referred to as a HARQ-ACK retransmission indicator). Each of the fields may be allocated a certain number of bits as illustrated.

If the CRC of the DCI format600A is scrambled with the C-RNTI, and if the HARQ feedback retransmission indicator field602is set to a certain value (e.g., 1) indicating to transmit the HARQ feedback retransmission, the MCS field604of transport block 1 may be interpreted as the HARQ feedback retransmission offset (e.g., the time offset408). For example, the value of ‘00000’ for the MCS field604may correspond to the lowest value (e.g., −7 slots) for the HARQ feedback retransmission offset, the value of ‘11111’ for the MCS field604may correspond to the largest value (e.g., 24 slots) for the HARQ feedback retransmission.

If the CRC of the DCI format600A is scrambled with the CS-RNTI, and if the HARQ feedback retransmission indicator field602is set to a certain value (e.g., 1) indicating to transmit the HARQ feedback retransmission, the MCS field604may be allowed to indicate release of SPS. For example, the value of ‘11111’ for the MCS field604may indicate release of SPS or CG; and the remaining values (‘00000’, ‘00001’, . . . , ‘11110’) for the MCS field604may be used to indicate the HARQ feedback retransmission offset. As an example, the value of ‘00000’ for the MCS field604may indicate −7 slots for the HARQ feedback transmission offset, and the value of ‘11110’ for the MCS field604may indicate 23 slots for the HARQ feedback transmission offset.

FIG.6Bis a diagram illustrating an example DCI format600B, in accordance with certain aspects of the present disclosure. In this example, the DCI format600B may include a DCI format 1_1 or a DCI format 1_2 used to schedule a HARQ feedback retransmission. If the CRC of the DCI format600B is scrambled with the CS-RNTI, and if the HARQ feedback retransmission indicator field602is set to a certain value (e.g., 1) indicating to transmit the HARQ feedback retransmission, the MCS field604may be allowed to indicate release of SPS or CG, and other field(s)606may be used to indicate the HARQ feedback retransmission offset. For example, the other field(s)606used to indicate the HARQ feedback retransmission offset may include the NDI field associated with transport block 1, the redundancy version field associated with transport block 1, the HARQ process number field, the antenna ports field, the SRS request field, the DMRS sequence initialization field, or any combination thereof. Assuming the HARQ feedback retransmission offset corresponds to a value of 32 values, any 5 bits from the other field(s)606may be used to indicate the HARQ feedback retransmission offset. In some cases, the HARQ feedback retransmission offset may correspond to other ranges of values, such as ranges represented by 1 bit, 2 bits, 3 bits, or 4 bits, for example.

FIG.7is a flow diagram illustrating example operations700for wireless communication, in accordance with certain aspects of the present disclosure. The operations700may be performed, for example, by a UE (such as the UE104in the wireless communication network100). The operations700may be implemented as software components that are executed and run on one or more processors (e.g., controller/processor280ofFIG.2). Further, the transmission and reception of signals by the UE in operations700may be enabled, for example, by one or more antennas (e.g., antennas252ofFIG.2). In certain aspects, the transmission and/or reception of signals by the UE may be implemented via a bus interface of one or more processors (e.g., controller/processor280) obtaining and/or outputting signals.

The operations700may optionally begin, at block702, where the UE may receive signaling indicating to reschedule HARQ feedback for transmission. The UE may receive the signaling from a network entity, such as the BS102. The signaling may include control signaling such as DCI, RRC signaling, medium access control (MAC) signaling, and/or system information. As an example, the signaling may include the DCI format600A and/or the DCI format600B. The DCI format may have a HARQ feedback retransmission indicator (e.g., the HARQ feedback retransmission indicator602) set to a value indicating to transmit a HARQ feedback retransmission and/or reschedule the HARQ feedback for transmission. In certain cases, the signaling may include first signaling and second signaling. The UE may be receiving the first signaling scheduling the HARQ feedback for transmission, such as DCI that schedules a downlink assignment with resources for HARQ feedback, as described herein with respect to activity502depicted inFIG.5. The UE may receive the second signaling indicating to reschedule the HARQ feedback, such as DCI that schedules the HARQ feedback retransmission, as described herein with respect to activity508depicted inFIG.5.

At block704, the UE may determine the HARQ feedback based at least in part on one or more fields of the signaling. The UE may determine the HARQ feedback for retransmission and/or rescheduling based on a time offset (e.g., the time offset408) associated with the HARQ feedback indicated in the signaling, for example, as described herein with respect toFIGS.4,6A, and6B. For example, the second signaling may identify the time offset in an MCS field associated with transport block 1 and/or other fields in a DCI format. The UE may determine the time offset associated with the HARQ feedback based on the field(s) of the second signaling. The UE may identify the HARQ feedback based on a first time position (e.g., slot n) associated with the time offset relative to when the second signaling is received (e.g., slot m) matching a second time position (e.g., slot n) associated with when the HARQ feedback was scheduled for transmission by the first signaling. The UE may identify the HARQ feedback for transmission based on n=m−HARQ_retx_offset, for example, as described herein with respect toFIG.4.

At block706, the UE may transmit the HARQ feedback based on the determination. For example, the UE may transmit the HARQ feedback to the network entity as described herein with respect toFIG.5.

In certain aspects, DCI having a CRC scrambled with a C-RNTI may use the MCS field in transport block 1 to indicate the HARQ feedback retransmission offset or secondary cell dormancy state(s). If a CRC of the signaling (e.g., the second signaling) is scrambled with a C-RNTI, the signaling may include a field (e.g., HARQ feedback retransmission indicator field602) set to a value (e.g., 1) indicating to transmit the HARQ feedback as a retransmission or rescheduled transmission. The one or more fields may include a MCS field associated with a transport block (e.g., transport block 1). If the CRC of the signaling (e.g., the second signaling) is scrambled with the C-RNTI, and if the field is set to a certain value (e.g., 1) indicating to transmit the HARQ feedback as a retransmission or rescheduled transmission, the UE may interpret the MCS field as the HARQ feedback retransmission offset (e.g., the time offset408).

For certain aspects, DCI having the CRC scrambled with a CS-RNTI may use the MCS field in transport block 1 to indicate to release SPS or indicate the HARQ feedback retransmission offset. In certain cases, if a CRC of the signaling (e.g., the second signaling) is scrambled with a CS-RNTI, the signaling may not be allowed to indicate release of SPS. If the CRC of the signaling (e.g., the second signaling) is scrambled with the CS-RNTI, and if a field (e.g., HARQ feedback retransmission indicator field602) in the signaling is set to a value (e.g., 1) indicating to transmit the HARQ feedback as a retransmission or a rescheduled transmission, the UE may interpret the MCS field associated with transport block 1 as indicating the HARQ feedback retransmission offset, and the MCS field may not be allowed to indicate release of SPS.

In certain aspects, if a CRC of the signaling is scrambled with a CS-RNTI, the signaling (e.g., the second signaling) is allowed to indicate release of SPS. In some cases, if the CRC of the signaling (e.g., the second signaling) is scrambled with the CS-RNTI, and if a field (e.g., HARQ feedback retransmission indicator field602) in the signaling is set to a value (e.g., 1) indicating to transmit the HARQ feedback as a retransmission or a rescheduled transmission, the UE may interpret the MCS field associated with transport block 1 indicating release of SPS or indicating the HARQ feedback retransmission offset. For example, the one or more fields may identify the time offset associated with the HARQ feedback or to release the SPS.

In certain cases, other field(s) may be used to indicate the HARQ feedback transmission offset, for example, as described herein with respect toFIG.6B. If the CRC of the signaling (e.g., the second signaling) is scrambled with the CS-RNTI, and if a field (e.g., HARQ feedback retransmission indicator field602) in the signaling is set to a value (e.g., 1) indicating to transmit the HARQ feedback as a retransmission or a rescheduled transmission, the UE may interpret the MCS field associated with transport block 1 indicating release of SPS and one or more other fields as indicating the HARQ feedback retransmission offset. For example, the one or more fields may include a NDI field associated with a transport block (e.g., transport block 1), a redundancy version (RV) field associated with the transport block, a DMRS sequence initialization field, a SRS request field, or any combination thereof.

For certain aspects, the UE may receive a configuration indicating how to interpret the MCS field associated with transport block 1 of certain DCI format(s) (e.g., DCI format 1_1 and/or DCI format 1_2). In some cases, the UE may receive a configuration indicating one or more values removed from a range of values associated with the time offset. For example, the UE configuration may identify that the two highest values (e.g., 23 and 24 slots) are removed from the range of values associated with the time offset. To determine the HARQ feedback, the UE may determine the HARQ feedback based at least in part on the one or more fields of the second signaling and the configuration.

In certain aspects, the HARQ feedback may identify the ACK-NACK state associated with one or transmissions. For example, the HARQ feedback may identify the ACK-NACK state associated with specific transmissions based on the respective CBG, TB, HARQ process, carrier, and/or serving cell. The HARQ feedback may include one or more ACKs and/or one or more NACKs. The HARQ feedback may include one or more HARQ process IDs, for example, as a list of HARQ process IDs. For certain aspects, the HARQ feedback retransmission may be used for specific HARQ codebook types. For example, the HARQ feedback may be associated with a Type-1 HARQ-ACK codebook, a Type-2 HARQ-ACK codebook, a Type-3 HARQ-ACK codebook, an enhancement thereof, or any combination thereof.

FIG.8is a flow diagram illustrating example operations800for wireless communication, in accordance with certain aspects of the present disclosure. The operations800may be performed, for example, by a network entity (such as the BS102in the wireless communication network100). The operations800may be complementary to the operations700performed by the UE. The operations800may be implemented as software components that are executed and run on one or more processors (e.g., controller/processor240ofFIG.2). Further, the transmission and reception of signals by the network entity in operations800may be enabled, for example, by one or more antennas (e.g., antennas234ofFIG.2). In certain aspects, the transmission and/or reception of signals by the network entity may be implemented via a bus interface of one or more processors (e.g., controller/processor240) obtaining and/or outputting signals. As used herein, a network entity may refer to a communication device in a radio access network (RAN), such as a radio unit of a base station, a base station, and/or a network controller, which may control the operations of one or more base stations and/or one or more units of a base station. A network entity may be implemented as a device or unit of a disaggregated base station or disaggregated RAN.

The operations800may optionally begin, at block802, where the network entity may send (e.g., transmit, provide, and/or output), to a UE (e.g., the UE104), signaling indicating to reschedule a HARQ feedback for transmission. The signaling may identify the HARQ feedback based at least in part on one or more fields of the signaling. The signaling may include first signaling and second signaling. The network entity may send, to the UE, first signaling scheduling the HARQ feedback for transmission, such as DCI that schedules a downlink assignment with resources for HARQ feedback, as described herein with respect to activity502depicted inFIG.5. The network entity may send, to the UE, second signaling indicating to reschedule the HARQ feedback. The second signaling may identify a time offset (e.g., the time offset408) associated with the HARQ feedback based on the one or more fields of the second signaling. A first time position (e.g., slot n) associated with the time offset relative to when the second signaling is sent (e.g., slot m) may match a second time position (e.g., slot n) associated with when the HARQ feedback was scheduled for transmission by the first signaling.

At block802, the network entity may obtain the HARQ feedback in response to the signaling. For example, the network entity may receive the HARQ feedback from the UE as described herein with respect toFIG.5.

In aspects, the signaling may be formatted as described herein with respect toFIGS.6A,6B, and7. In some cases, if a CRC of the signaling (e.g., the second signaling) is scrambled with a C-RNTI, the signaling may include a field (e.g., HARQ feedback retransmission indicator field602) set to a value (e.g., 1) indicating to transmit the HARQ feedback as a retransmission or rescheduled transmission, for example, as described herein with respect toFIG.6A. In certain cases, if a CRC of the signaling (e.g., the second signaling) is scrambled with a CS-RNTI, the signaling is not allowed to indicate release of SPS, for example, as described herein with respect toFIG.7. In some cases, if a CRC of the signaling (e.g., the second signaling) is scrambled with a CS-RNTI, the signaling is allowed to indicate release of SPS, for example, as described herein with respect toFIGS.6A,6B, and7.

For certain aspects, the network entity may send a configuration indicating how to interpret the MCS field associated with transport block 1 of certain DCI format(s) (e.g., DCI format 1_1 and/or DCI format 1_2). The network entity may send, to the UE, a configuration indicating one or more values removed from a range of values associated with the time offset, and the second signaling may identify the time offset based at least in part on the one or more fields of the second signaling and the configuration.

In certain aspects, the HARQ feedback may identify the ACK-NACK state associated with one or transmissions, for example, as described herein with respect toFIG.7. For certain aspects, the HARQ feedback retransmission may be used for specific HARQ codebook types, for example, as described herein with respect toFIG.7.

Example Wireless Communication Devices

FIG.9depicts an example communications device900that includes various components operable, configured, or adapted to perform operations for the techniques disclosed herein, such as the operations depicted and described with respect toFIGS.5-7. In some examples, communication device900may be a UE104as described, for example with respect toFIGS.1and2.

Communications device900includes a processing system902coupled to a transceiver908(e.g., a transmitter and/or a receiver). Transceiver908is configured to transmit (or send) and receive signals for the communications device900via an antenna910, such as the various signals as described herein. Processing system902may be configured to perform processing functions for communications device900, including processing signals received and/or to be transmitted by communications device900.

Processing system902includes one or more processors920coupled to a computer-readable medium/memory930via a bus906. In certain aspects, computer-readable medium/memory930is configured to store instructions (e.g., computer-executable code) that when executed by the one or more processors920, cause the one or more processors920to perform the operations illustrated inFIGS.5-7, or other operations for performing the various techniques discussed herein for retransmission or rescheduling of HARQ feedback.

In the depicted example, the one or more processors920include circuitry configured to implement the code stored in the computer-readable medium/memory930, including circuitry921for receiving, circuitry922for transmitting, and/or circuitry923for determining.

Various components of communications device900may provide means for performing the methods described herein, including with respect toFIGS.5-7.

In some examples, means for transmitting or sending (or means for outputting for transmission) may include the transceivers254and/or antenna(s)252of the UE104illustrated inFIG.2and/or transceiver908and antenna910of the communication device900inFIG.9.

In some examples, means for receiving (or means for obtaining) may include the transceivers254and/or antenna(s)252of the UE104illustrated inFIG.2and/or transceiver908and antenna910of the communication device900inFIG.9.

In some cases, rather than actually transmitting, for example, signals and/or data, a device may have an interface to output signals and/or data for transmission (a means for outputting). For example, a processor may output signals and/or data, via a bus interface, to a radio frequency (RF) front end for transmission. Similarly, rather than actually receiving signals and/or data, a device may have an interface to obtain the signals and/or data received from another device (a means for obtaining). For example, a processor may obtain (or receive) the signals and/or data, via a bus interface, from an RF front end for reception. In various aspects, an RF front end may include various components, including transmit and receive processors, transmit and receive MIMO processors, modulators, demodulators, and the like, such as depicted in the examples inFIG.2.

In some examples, means for transmitting, means for receiving, and/or means for determining and/or identifying may include various processing system components, such as: the one or more processors920inFIG.9, or aspects of the UE104depicted inFIG.2, including receive processor258, transmit processor264, TX MIMO processor266, and/or controller/processor280(including HARQ feedback retransmission component281).

Notably,FIG.9is an example, and many other examples and configurations of communication device900are possible.

FIG.10depicts an example communications device1000that includes various components operable, configured, or adapted to perform operations for the techniques disclosed herein, such as the operations depicted and described with respect toFIGS.5,6A,6B, and8. In some examples, communication device1000may be a BS102as described, for example with respect toFIGS.1and2.

Communications device1000includes a processing system1002coupled to a transceiver1008(e.g., a transmitter and/or a receiver). Transceiver1008is configured to transmit (or send) and receive signals for the communications device1000via an antenna1010, such as the various signals as described herein. Processing system1002may be configured to perform processing functions for communications device1000, including processing signals received and/or to be transmitted by communications device1000.

Processing system1002includes one or more processors1020coupled to a computer-readable medium/memory1030via a bus1006. In certain aspects, computer-readable medium/memory1030is configured to store instructions (e.g., computer-executable code) that when executed by the one or more processors1020, cause the one or more processors1020to perform the operations illustrated inFIGS.5,6A,6B, and8, or other operations for performing the various techniques discussed herein for retransmission or rescheduling of HARQ feedback.

In the depicted example, the one or more processors1020include circuitry configured to implement the code stored in the computer-readable medium/memory1030, including circuitry1021for sending (or transmitting) and/or circuitry1022for obtaining (or receiving).

Various components of communications device1000may provide means for performing the methods described herein, including with respect toFIGS.5,6A,6B, and8.

In some examples, means for transmitting or sending (or means for outputting for transmission) may include the transceivers232and/or antenna(s)234of the BS102illustrated inFIG.2and/or transceiver1008and antenna1010of the communication device1000inFIG.10.

In some examples, means for receiving (or means for obtaining) may include the transceivers232and/or antenna(s)234of the base station illustrated inFIG.2and/or transceiver1008and antenna1010of the communication device1000inFIG.10.

In some examples, means for transmitting and/or means for receiving may include various processing system components, such as: the one or more processors1020inFIG.10, or aspects of the BS102depicted inFIG.2, including receive processor238, transmit processor220, TX MIMO processor230, and/or controller/processor240(including HARQ feedback retransmission component241).

Notably,FIG.10is an example, and many other examples and configurations of communication device1000are possible.

Example Aspects

Aspect 1: A method of wireless communication by a user equipment, comprising: receiving signaling indicating to reschedule hybrid automatic repeat request (HARQ) feedback for transmission; determining the HARQ feedback based at least in part on one or more fields of the signaling; and transmitting the HARQ feedback based on the determination.

Aspect 2: The method of Aspect 1, wherein: receiving the signaling comprises: receiving first signaling scheduling the HARQ feedback for transmission; and receiving second signaling indicating to reschedule the HARQ feedback; and determining the HARQ feedback comprises: determining a time offset associated with the HARQ feedback based on the one or more fields of the second signaling; and identifying the HARQ feedback based on a first time position associated with the time offset relative to when the second signaling is received matching a second time position associated with when the HARQ feedback was scheduled for transmission by the first signaling.

Aspect 3: The method of Aspect 1 or 2, wherein if a cyclic redundancy check (CRC) of the signaling is scrambled with a cell radio network temporary identifier (C-RNTI), the signaling includes a field set to a value indicating to transmit the HARQ feedback.

Aspect 4: The method according to any of Aspects 1-3, wherein the one or more fields includes a modulation and coding scheme field associated with a transport block.

Aspect 5: The method of Aspect 1 or 2, wherein if a CRC of the signaling is scrambled with a configured scheduling RNTI (CS-RNTI), the signaling is not allowed to indicate release of semi-persistent scheduling.

Aspect 6: The method of Aspect 2, wherein if a CRC of the signaling is scrambled with a CS-RNTI, the signaling is allowed to indicate release of semi-persistent scheduling.

Aspect 7: The method of Aspect 6, wherein the one or more fields identify the time offset associated with the HARQ feedback or to release the semi-persistent scheduling.

Aspect 8: The method of Aspect 6 or 7, further comprising: receiving a configuration indicating one or more values removed from a range of values associated with the time offset; and wherein determining the HARQ feedback comprises determining the HARQ feedback based at least in part on the one or more fields of the second signaling and the configuration.

Aspect 9: The method according to any of Aspects 6-8, wherein the one or more fields includes: a new data indicator (NDI) field associated with a transport block; a redundancy version (RV) field associated with the transport block; a demodulation reference signal (DMRS) sequence initialization field; a sounding reference signal (SRS) request field; or any combination thereof.

Aspect 10: The method according to any of Aspects 1-9, wherein the signaling includes downlink control information.

Aspect 11: The method according to any of Aspects 1-10, wherein the HARQ feedback includes one or more acknowledgements or one or more negative acknowledgments.

Aspect 12: The method according to any of Aspects 1-11, wherein the HARQ feedback includes one or more HARQ process identifiers.

Aspect 13: The method according to any of Aspects 1-12, wherein the HARQ feedback is associated with a Type-1 or a Type-2 HARQ-Acknowledgement (HARQ-ACK) codebook.

Aspect 14: A method of wireless communication by a network entity, comprising: sending, to a user equipment (UE), signaling indicating to reschedule hybrid automatic repeat request (HARQ) feedback for transmission, wherein the signaling identifies the HARQ feedback based at least in part on one or more fields of the signaling; and obtaining the HARQ feedback in response to the signaling.

Aspect 15: The method of Aspect 14, wherein sending the signaling comprises: sending, to the UE, first signaling scheduling the HARQ feedback for transmission; and sending, to the UE, second signaling indicating to reschedule the HARQ feedback, wherein the second signaling identifies a time offset associated with the HARQ feedback based on the one or more fields of the second signaling, wherein a first time position associated with the time offset relative to when the second signaling is sent matches a second time position associated with when the HARQ feedback was scheduled for transmission by the first signaling.

Aspect 16: The method of Aspect 14 or 15, wherein if a cyclic redundancy check (CRC) of the signaling is scrambled with a cell radio network temporary identifier (C-RNTI), the signaling includes a field set to a value indicating to transmit the HARQ feedback.

Aspect 17: The method according to any of Aspects 14-16, wherein the one or more fields includes a modulation and coding scheme field associated with a transport block.

Aspect 18: The method of Aspect 14 or 15, wherein if a CRC of the signaling is scrambled with a configured scheduling RNTI (CS-RNTI), the signaling is not allowed to indicate release of semi-persistent scheduling.

Aspect 19: The method of Aspect 15, wherein if a CRC of the signaling is scrambled with a CS-RNTI, the signaling is allowed to indicate release of semi-persistent scheduling.

Aspect 20: The method of Aspect 19, wherein the one or more fields identify the time offset associated with the HARQ feedback or to release the semi-persistent scheduling.

Aspect 21: The method of Aspect 19 or 20, further comprising: sending, to the UE, a configuration indicating one or more values removed from a range of values associated with the time offset; and wherein the second signaling identifies the time offset based at least in part on the one or more fields of the second signaling and the configuration.

Aspect 22: The method according to any of Aspects 19-21, wherein the one or more fields includes: a new data indicator (NDI) field associated with a transport block; a redundancy version (RV) field associated with the transport block; a demodulation reference signal (DMRS) sequence initialization field; a sounding reference signal (SRS) request field; or any combination thereof.

Aspect 23: The method according to any of Aspects 14-22, wherein the signaling includes downlink control information.

Aspect 24: The method according to any of Aspects 14-23, wherein the HARQ feedback includes one or more acknowledgements or one or more negative acknowledgments.

Aspect 25: The method according to any of Aspects 14-24, wherein the HARQ feedback includes one or more HARQ process identifiers.

Aspect 26: The method according to any of Aspects 14-25, wherein the HARQ feedback is associated with a Type-1 or a Type-2 HARQ-Acknowledgement (HARQ-ACK) codebook.

Aspect 27: An apparatus for wireless communication, comprising: a memory; and a processor coupled to the memory, the processor being configured to: receive signaling indicating to reschedule hybrid automatic repeat request (HARQ) feedback for transmission, determine the HARQ feedback based at least in part on one or more fields of the signaling, and transmit the HARQ feedback based on the determination.

Aspect 28: The apparatus of Aspect 27, wherein: to receive the signaling, the processor is further configured to receive first signaling scheduling the HARQ feedback for transmission; and receive second signaling indicating to reschedule the HARQ feedback; and to determine the HARQ feedback, the processor is further configured to determine a time offset associated with the HARQ feedback based on the one or more fields of the second signaling; and identify the HARQ feedback based on a first time position associated with the time offset relative to when the second signaling is received matching a second time position associated with when the HARQ feedback was scheduled for transmission by the first signaling.

Aspect 29: The apparatus of Aspect 27 or 28, wherein if a cyclic redundancy check (CRC) of the signaling is scrambled with a cell radio network temporary identifier (C-RNTI), the signaling includes a field set to a value indicating to transmit the HARQ feedback.

Aspect 30: The apparatus according to any of Aspects 27-29, wherein the one or more fields includes a modulation and coding scheme field associated with a transport block.

Aspect 31: The apparatus of Aspect 27 or 28, wherein if a CRC of the signaling is scrambled with a configured scheduling RNTI (CS-RNTI), the signaling is not allowed to indicate release of semi-persistent scheduling.

Aspect 32: The apparatus of Aspect 28, wherein if a CRC of the signaling is scrambled with a CS-RNTI, the signaling is allowed to indicate release of semi-persistent scheduling.

Aspect 33: The apparatus of Aspect 32, wherein the one or more fields identify the time offset associated with the HARQ feedback or to release the semi-persistent scheduling.

Aspect 34: The apparatus of Aspect 32 or 33, wherein: the processor is further configured to receive a configuration indicating one or more values removed from a range of values associated with the time offset; and to determine the HARQ feedback, the processor is further configured to determine the HARQ feedback based at least in part on the one or more fields of the second signaling and the configuration.

Aspect 35: The apparatus according to any of Aspects 32-34, wherein the one or more fields includes: a new data indicator (NDI) field associated with a transport block; a redundancy version (RV) field associated with the transport block; a demodulation reference signal (DMRS) sequence initialization field; a sounding reference signal (SRS) request field; or any combination thereof.

Aspect 36: The apparatus according to any of Aspects 27-35, wherein the signaling includes downlink control information.

Aspect 37: The apparatus according to any of Aspects 27-36, wherein the HARQ feedback includes one or more acknowledgements or one or more negative acknowledgments.

Aspect 38: The apparatus according to any of Aspects 27-37, wherein the HARQ feedback includes one or more HARQ process identifiers.

Aspect 39: The apparatus according to any of Aspects 27-38, wherein the HARQ feedback is associated with a Type-1 or a Type-2 HARQ-Acknowledgement (HARQ-ACK) codebook.

Aspect 40: An apparatus for wireless communication, comprising: a memory; and a processor coupled to the memory, the processor being configured to: send, to a user equipment (UE), signaling indicating to reschedule hybrid automatic repeat request (HARQ) feedback for transmission, wherein the signaling identifies the HARQ feedback based at least in part on one or more fields of the signaling, and obtain the HARQ feedback in response to the signaling.

Aspect 41: The apparatus of Aspect 40, wherein to send the signaling, the processor is configured to: send, to the UE, first signaling scheduling the HARQ feedback for transmission; and send, to the UE, second signaling indicating to reschedule the HARQ feedback, wherein the second signaling identifies a time offset associated with the HARQ feedback based on the one or more fields of the second signaling, wherein a first time position associated with the time offset relative to when the second signaling is sent matches a second time position associated with when the HARQ feedback was scheduled for transmission by the first signaling.

Aspect 42: The apparatus of Aspect 40 or 41, wherein if a cyclic redundancy check (CRC) of the signaling is scrambled with a cell radio network temporary identifier (C-RNTI), the signaling includes a field set to a value indicating to transmit the HARQ feedback.

Aspect 43: The apparatus according to any of Aspects 40-42, wherein the one or more fields includes a modulation and coding scheme field associated with a transport block.

Aspect 44: The apparatus of Aspect 40 or 41, wherein if a CRC of the signaling is scrambled with a configured scheduling RNTI (CS-RNTI), the signaling is not allowed to indicate release of semi-persistent scheduling.

Aspect 45: The apparatus of Aspect 41, wherein if a CRC of the signaling is scrambled with a CS-RNTI, the signaling is allowed to indicate release of semi-persistent scheduling.

Aspect 46: The apparatus of Aspect 45, wherein the one or more fields identify the time offset associated with the HARQ feedback or to release the semi-persistent scheduling.

Aspect 47: The apparatus of Aspect 45 or 46, wherein the processor is further configured to: send, to the UE, a configuration indicating one or more values removed from a range of values associated with the time offset; and wherein the second signaling identifies the time offset based at least in part on the one or more fields of the second signaling and the configuration.

Aspect 48: The apparatus according to any of Aspects 45-47, wherein the one or more fields includes: a new data indicator (NDI) field associated with a transport block; a redundancy version (RV) field associated with the transport block; a demodulation reference signal (DMRS) sequence initialization field; a sounding reference signal (SRS) request field; or any combination thereof.

Aspect 49: The apparatus according to any of Aspects 40-48, wherein the signaling includes downlink control information.

Aspect 50: The apparatus according to any of Aspects 40-49, wherein the HARQ feedback includes one or more acknowledgements or one or more negative acknowledgments.

Aspect 51: The apparatus according to any of Aspects 40-50, wherein the HARQ feedback includes one or more HARQ process identifiers.

Aspect 52: The apparatus according to any of Aspects 40-51, wherein the HARQ feedback is associated with a Type-1 or a Type-2 HARQ-Acknowledgement (HARQ-ACK) codebook.

Aspect 53: An apparatus, comprising: a memory comprising computer-executable instructions; one or more processors configured to execute the computer-executable instructions and cause the apparatus to perform a method in accordance with any of Aspects 1-26.

Aspect 54: An apparatus, comprising means for performing a method in accordance with any of Aspects 1-26.

Aspect 56: A computer program product embodied on a computer-readable storage medium comprising code for performing a method in accordance with any of Aspects 1-26.

Additional Wireless Communication Network Considerations

The techniques and methods described herein may be used for various wireless communications networks (or wireless wide area network (WWAN)) and radio access technologies (RATs). While aspects may be described herein using terminology commonly associated with 3G, 4G, and/or 5G (e.g., 5G new radio (NR)) wireless technologies, aspects of the present disclosure may likewise be applicable to other communication systems and standards not explicitly mentioned herein.

5G wireless communication networks may support various advanced wireless communication services, such as enhanced mobile broadband (eMBB), millimeter wave (mmWave), machine type communications (MTC), and/or mission critical targeting ultra-reliable, low-latency communications (URLLC). These services, and others, may include latency and reliability requirements.

Returning toFIG.1, various aspects of the present disclosure may be performed within the example wireless communication network100.

In 3GPP, the term “cell” can refer to a coverage area of a NodeB and/or a narrowband subsystem serving this coverage area, depending on the context in which the term is used. In NR systems, the term “cell” and BS, next generation NodeB (gNB or gNodeB), access point (AP), distributed unit (DU), carrier, or transmission reception point may be used interchangeably. A BS may provide communication coverage for a macro cell, a pico cell, a femto cell, and/or other types of cells.

A macro cell may generally cover a relatively large geographic area (e.g., several kilometers in radius) and may allow unrestricted access by UEs with service subscription. A pico cell may cover a relatively small geographic area (e.g., a sports stadium) and may allow unrestricted access by UEs with service subscription. A femto cell may cover a relatively small geographic area (e.g., a home) and may allow restricted access by UEs having an association with the femto cell (e.g., UEs in a Closed Subscriber Group (CSG) and UEs for users in the home). A BS for a macro cell may be referred to as a macro BS. A BS for a pico cell may be referred to as a pico BS. A BS for a femto cell may be referred to as a femto BS, home BS, or a home NodeB.

Some base stations, such as BS180(e.g., gNB) may operate in a traditional sub-6 GHz spectrum, in millimeter wave (mmWave) frequencies, and/or near mmWave frequencies in communication with the UE104. When the BS180operates in mmWave or near mmWave frequencies, the BS180may be referred to as an mmWave base station.

The communication links120between BSs102and, for example, UEs104, may be through one or more carriers. For example, BSs102and UEs104may use spectrum up to YMHz (e.g., 5, 10, 15, 20, 100, 400, and other MHz) bandwidth per carrier allocated in a carrier aggregation of up to a total of Yx MHz (x component carriers) used for transmission in each direction. The carriers may or may not be adjacent to each other. Allocation of carriers may be asymmetric with respect to DL and UL (e.g., more or fewer carriers may be allocated for DL than for UL). The component carriers may include a primary component carrier and one or more secondary component carriers. A primary component carrier may be referred to as a primary cell (PCell) and a secondary component carrier may be referred to as a secondary cell (SCell).

Wireless communication network100further includes a Wi-Fi access point (AP)150in communication with Wi-Fi stations (STAs)152via communication links154in, for example, a 2.4 GHz and/or 5 GHz unlicensed frequency spectrum. When communicating in an unlicensed frequency spectrum, the STAs152/AP150may perform a clear channel assessment (CCA) prior to communicating in order to determine whether the channel is available.

EPC160may include a Mobility Management Entity (MME)162, other MMES164, a Serving Gateway166, a Multimedia Broadcast Multicast Service (MBMS) Gateway168, a Broadcast Multicast Service Center (BM-SC)170, and a Packet Data Network (PDN) Gateway172. MME162may be in communication with a Home Subscriber Server (HSS)174. MME162is the control node that processes the signaling between the UEs104and the EPC160. Generally, MME162provides bearer and connection management.

5GC190may include an Access and Mobility Management Function (AMF)192, other AMFs193, a Session Management Function (SMF)194, and a User Plane Function (UPF)195. AMF192may be in communication with a Unified Data Management (UDM)196.

AMF192is generally the control node that processes the signaling between UEs104and 5GC190. Generally, AMF192provides QoS flow and session management.

All user Internet protocol (IP) packets are transferred through UPF195, which is connected to the IP Services197, and which provides UE IP address allocation as well as other functions for 5GC190. IP Services197may include, for example, the Internet, an intranet, an IP Multimedia Subsystem (IMS), a PS Streaming Service, and/or other IP services.

Returning toFIG.2, various example components of BS102and UE104(e.g., the wireless communication network100ofFIG.1) are depicted, which may be used to implement aspects of the present disclosure.

At BS102, a transmit processor220may receive data from a data source212and control information from a controller/processor240. The control information may be for the physical broadcast channel (PBCH), physical control format indicator channel (PCFICH), physical hybrid ARQ indicator channel (PHICH), physical downlink control channel (PDCCH), group common PDCCH (GC PDCCH), and others. The data may be for the physical downlink shared channel (PDSCH), in some examples.

A medium access control (MAC)-control element (MAC-CE) is a MAC layer communication structure that may be used for control command exchange between wireless nodes. The MAC-CE may be carried in a shared channel such as a physical downlink shared channel (PDSCH), a physical uplink shared channel (PUSCH), or a physical sidelink shared channel (PSSCH).

Transmit processor220may process (e.g., encode and symbol map) the data and control information to obtain data symbols and control symbols, respectively. Transmit processor220may also generate reference symbols, such as for the primary synchronization signal (PSS), secondary synchronization signal (SSS), PBCH demodulation reference signal (DMRS), and channel state information reference signal (CSI-RS).

At UE104, antennas252a-252rmay receive the downlink signals from the BS102and may provide received signals to the demodulators (DEMODs) in transceivers254a-254r, respectively. Each demodulator in transceivers254a-254rmay condition (e.g., filter, amplify, downconvert, and digitize) a respective received signal to obtain input samples. Each demodulator may further process the input samples (e.g., for OFDM) to obtain received symbols.

MIMO detector256may obtain received symbols from all the demodulators in transceivers254a-254r, perform MIMO detection on the received symbols if applicable, and provide detected symbols. Receive processor258may process (e.g., demodulate, deinterleave, and decode) the detected symbols, provide decoded data for the UE104to a data sink260, and provide decoded control information to a controller/processor280.

On the uplink, at UE104, transmit processor264may receive and process data (e.g., for the physical uplink shared channel (PUSCH)) from a data source262and control information (e.g., for the physical uplink control channel (PUCCH) from the controller/processor280. Transmit processor264may also generate reference symbols for a reference signal (e.g., for the sounding reference signal (SRS)). The symbols from the transmit processor264may be precoded by a TX MIMO processor266if applicable, further processed by the modulators in transceivers254a-254r(e.g., for SC-FDM), and transmitted to BS102.

At BS102, the uplink signals from UE104may be received by antennas234a-t, processed by the demodulators in transceivers232a-232t, detected by a MIMO detector236if applicable, and further processed by a receive processor238to obtain decoded data and control information sent by UE104. Receive processor238may provide the decoded data to a data sink239and the decoded control information to the controller/processor240.

Memories242and282may store data and program codes for BS102and UE104, respectively.

Scheduler244may schedule UEs for data transmission on the downlink and/or uplink.

As above,FIGS.3A,3B,3C, and3Ddepict various example aspects of data structures for a wireless communication network, such as wireless communication network100ofFIG.1.

In various aspects, the 5G frame structure may be frequency division duplex (FDD), in which for a particular set of subcarriers (carrier system bandwidth), subframes within the set of subcarriers are dedicated for either DL or UL. 5G frame structures may also be time division duplex (TDD), in which for a particular set of subcarriers (carrier system bandwidth), subframes within the set of subcarriers are dedicated for both DL and UL. In the examples provided byFIGS.3A and3C, the 5G frame structure is assumed to be TDD, with subframe 4 being configured with slot format 28 (with mostly DL), where D is DL, U is UL, and X is flexible for use between DL/UL, and subframe 3 being configured with slot format 34 (with mostly UL). While subframes 3, 4 are shown with slot formats 34, 28, respectively, any particular subframe may be configured with any of the various available slot formats 0-61. Slot formats 0, 1 are all DL, UL, respectively. Other slot formats 2-61 include a mix of DL, UL, and flexible symbols. UEs are configured with the slot format (dynamically through DL control information (DCI), or semi-statically/statically through radio resource control (RRC) signaling) through a received slot format indicator (SFI). Note that the description below applies also to a 5G frame structure that is TDD.

Other wireless communication technologies may have a different frame structure and/or different channels. A frame (10 ms) may be divided into 10 equally sized subframes (1 ms). Each subframe may include one or more time slots. Subframes may also include mini-slots, which may include 7, 4, or 2 symbols. In some examples, each slot may include 7 or 14 symbols, depending on the slot configuration.

For example, for slot configuration 0, each slot may include 14 symbols, and for slot configuration 1, each slot may include 7 symbols. The symbols on DL may be cyclic prefix (CP) OFDM (CP-OFDM) symbols. The symbols on UL may be CP-OFDM symbols (for high throughput scenarios) or discrete Fourier transform (DFT) spread OFDM (DFT-s-OFDM) symbols (also referred to as single carrier frequency-division multiple access (SC-FDMA) symbols) (for power limited scenarios; limited to a single stream transmission).

As illustrated inFIG.3A, some of the REs carry reference (pilot) signals (RS) for a UE (e.g., UE104ofFIGS.1and2). The RS may include demodulation RS (DM-RS) (indicated as Rx for one particular configuration, where 100× is the port number, but other DM-RS configurations are possible) and channel state information reference signals (CSI-RS) for channel estimation at the UE. The RS may also include beam measurement RS (BRS), beam refinement RS (BRRS), and phase tracking RS (PT-RS).

FIG.3Billustrates an example of various DL channels within a subframe of a frame. The physical downlink control channel (PDCCH) carries DCI within one or more control channel elements (CCEs), each CCE including nine RE groups (REGs), each REG including four consecutive REs in an OFDM symbol.

A primary synchronization signal (PSS) may be within symbol2of particular subframes of a frame. The PSS is used by a UE (e.g.,104ofFIGS.1and2) to determine subframe/symbol timing and a physical layer identity.

A secondary synchronization signal (SSS) may be within symbol4of particular subframes of a frame. The SSS is used by a UE to determine a physical layer cell identity group number and radio frame timing.

Additional Considerations