Patent Description:
<NPL>) relates to HARQ-ACK feedback issues of DL SPS with respect to the support of shorter SPS periodicities and multiple SPS configurations.

The invention is set out by the independent claims. Preferable embodiments are set out by the dependent claims.

Embodiments disclosed herein generally relate to communication networks, wireless and/or wired. For example, one or more embodiments disclosed herein are related to methods and apparatus for uplink control enhancement in wireless communications.

In one embodiment, a method implemented by a wireless transmit/receive unit (WTRU) for wireless communications comprises receiving information related to a set of downlink semi-persistent scheduling (SPS) configurations, and receiving one or more downlink SPS transmissions based on the received information. The method comprises determining a payload of uplink control information (UCI) for transmission over an uplink channel, and the payload comprises a set of hybrid automatic repeat request (HARQ) feedback bits based on the received information. The method also comprises determining that at least one triggering condition for segmenting the set of HARQ feedback bits is satisfied, and determining at least a portion of the set of HARQ feedback bits based on at least a downlink SPS configuration of the set of downlink SPS configurations, wherein the determined portion of the set of HARQ feedback bits corresponds to a respective subset of the received one or more downlink SPS transmissions. The method further comprises transmitting at least the determined portion of the set of HARQ feedback bits using the uplink channel.

A more detailed understanding may be had from the detailed description below, given by way of example in conjunction with the drawings appended hereto. Figures in such drawings, like the detailed description, are examples. As such, the Figures and the detailed description are not to be considered limiting, and other equally effective examples are possible and likely. Furthermore, like reference numerals in the figures indicate like elements, and wherein:.

In the following detailed description, numerous specific details are set forth to provide a thorough understanding of embodiments and/or examples disclosed herein. However, it will be understood that such embodiments and examples may be practiced without some or all of the specific details set forth herein. In other instances, well-known methods, procedures, components and circuits have not been described in detail, so as not to obscure the following description. Further, embodiments and examples not specifically described herein may be practiced in lieu of, or in combination with, the embodiments and other examples described, disclosed or otherwise provided explicitly, implicitly and/or inherently (collectively "provided") herein. Although various embodiments are described and/or claimed herein in which an apparatus, system, device, etc. and/or any element thereof carries out an operation, process, algorithm, function, etc. and/or any portion thereof, it is to be understood that any embodiments described and/or claimed herein assume that any apparatus, system, device, etc. and/or any element thereof is configured to carry out any operation, process, algorithm, function, etc. and/or any portion thereof.

The methods, apparatuses and systems provided herein are well-suited for communications involving both wired and wireless networks. Wired networks are well-known. An overview of various types of wireless devices and infrastructure is provided with respect to <FIG>, where various elements of the network may utilize, perform, be arranged in accordance with and/or be adapted and/or configured for the methods, apparatuses and systems provided herein.

By way of example, the base stations 114a, 114b may be a base transceiver station (BTS), a Node-B, an eNode B, a Home Node B, a Home eNode B, a gNB, a New Radio (NR) NodeB, a site controller, an access point (AP), a wireless router, and the like.

Thus, in one embodiment, the base station 114a may include three transceivers, e.g., one for each sector of the cell.

In other embodiments, the base station 114a and the WTRUs 102a, 102b, 102c may implement radio technologies such as IEEE <NUM> (e.g., Wireless Fidelity (WiFi), IEEE <NUM> (e.g., Worldwide Interoperability for Microwave Access (WiMAX)), CDMA2000, CDMA2000 1X, CDMA2000 EV-DO, Interim Standard <NUM> (IS-<NUM>), Interim Standard <NUM> (IS-<NUM>), Interim Standard <NUM> (IS-<NUM>), Global System for Mobile communications (GSM), Enhanced Data rates for GSM Evolution (EDGE), GSM EDGE (GERAN), and the like.

The base station 114b in <FIG> may be a wireless router, a Home Node B, a Home eNode B, or an access point, for example, and may utilize any suitable RAT for facilitating wireless connectivity in a localized area, such as a place of business, a home, a vehicle, a campus, an industrial facility, an air corridor (e.g., for use by drones), a roadway, and the like. In yet another embodiment, the base station 114b and the WTRUs 102c, 102d may utilize a cellular-based RAT (e.g., WCDMA, CDMA2000, GSM, LTE, LTE-A, LTE-A Pro, NR, etc.) to establish a picocell or femtocell.

The full duplex radio may include an interference management unit <NUM> to reduce and or substantially eliminate self-interference via either hardware (e.g., a choke) or signal processing via a processor (e.g., a separate processor (not shown) or via processor <NUM>).

The MME <NUM> may be connected to each of the eNode-Bs 160a, 160b, 160c in the RAN <NUM> via an S1 interface and may serve as a control node.

In some representative embodiments, the other network <NUM> may be a WLAN.

For example, different network slices may be established for different use cases such as services relying on ultra-reliable low latency (URLLC) access, services relying on enhanced massive mobile broadband (eMBB) access, services for machine-type communication (MTC) access, and/or the like.

The SMF 183a, 183b may perform other functions, such as managing and allocating a WTRU or UE IP address, managing PDU sessions, controlling policy enforcement and QoS, providing downlink data notifications, and the like.

The emulation device may be directly coupled to another device for purposes of testing and/or may performing testing using over-the-air (OTA) wireless communications.

Embodiments disclosed herein generally relate to communication networks, wireless and/or wired. For example, one or more embodiments disclosed herein are related to methods and apparatus for uplink control enhancement (e.g., overhead reduction) in wireless communications.

New Radio (NR) technology may support and/or serve one or more services to one or multiple WTRUs. Such services may be varying and/or different latency and reliability requirements. Examples of the services that NR technology may support include URLLC and/or eMBB services. To better support operations with different types of services, such as URLLC and eMBB, mechanisms have been introduced for enabling reception of low latency certain for enabling reception of low latency and/or high reliable transmissions. The reliability, accuracy, and timeliness of feedback reports (e.g., CQI, and HARQ-ACK) may be needed to meet varying and/or different latency and reliability requirements of the various services.

NR supports one or more flexible transmission durations within a slot. NR supports semi-static resources for data transmissions on uplink (UL) and/or downlink (DL) directions. Configured grant (CG) type-<NUM> and configured grant (CG) type-<NUM> may be used for uplink transmissions. For CG type-<NUM>, the network may semi-statically configure an uplink grant and the WTRU may autonomously use the uplink grant without a L1 indication/activation. Configured grant (CG) type-<NUM> is similar to CG type-<NUM>, but L1 activation is needed so that a WTRU may start using the configured grant for uplink transmissions. NR supports DL semi-persistent scheduling (SPS) resources (or DL configured grants (CGs)), including those on which the WTRU may receive DL data on active DL CGs with no scheduling necessary for each DL transport block (TB).

NR supports UL and DL services having different QoS requirements within a single WTRU, having traffic of varying latency and reliability requirements. NR supports time-sensitive communications and networking, including deterministic and non-deterministic time-sensitive networking (TSN) traffic patterns and flows, and these patterns and flows may be prevalent in factory automation settings using licensed and/or unlicensed spectrum.

In various embodiments, channel state information (CSI) may include one or more of the following: channel quality index (CQI), rank indicator (RI), precoding matrix index (PMI), an Layer <NUM> (L1 or PHY layer) channel measurement (e.g., reference signal received power (RSRP) such as L1-RSRP, or signal-to-interference-plus-noise ratio (SINR)), CSI-RS resource indicator (CRI), synchronization signal (SS) / physical broadcast channel (PBCH) block resource indicator (SSBRI), layer indicator (LI), and/or any other measurement quantity measured by the WTRU from configured CSI-RS and/or SS/PBCH block(s).

In various embodiments, UL control information (UCI) may include one or more of the following: CSI, Hybrid Automatic Repeat Request (HARQ) feedback for one or more HARQ processes, scheduling request (SR), link recovery request (LRR), CG-UCI, and/or other control information bits that may be transmitted on Physical Uplink Control Channel (PUCCH) or Physical Uplink Shared Channel (PUSCH).

In various embodiments, channel conditions may be or include any conditions relating to the state of a radio or a channel, and the channel conditions may be determined by a WTRU from one or more of the following: a WTRU (or UE) measurement (e.g., L1/SINR/RSRP, CQI / Modulation and Coding Scheme (MCS), channel occupancy, Received Signal Strength Indicator (RSSI), power headroom, or energy exposure headroom), L3/mobility-based measurements (e.g., RSRP, Reference Signal Received Quality (RSRQ)), an Radio Link Monitoring (RLM) state, and/or channel availability in unlicensed spectrum. Channel availability may include a determination of whether the channel being occupied based on determination of a listen-before-talk (LBT) procedure, or whether the channel being deemed to have experienced a consistent LBT failure.

There may be multiple active CGs/SPSs, multiple time-sensitive communications (TSC) traffic patterns, and/or shorter (e.g., symbol-level) SPS periodicities, and there may be plenty of HARQ feedback bits to report simultaneously, especially in time-division duplexing (TDD) mode when the DL portion is longer than the UL portion. In some cases, a WTRU may not be able to report all HARQ feedback bits (e.g., one or more pending HARQ feedback bits) in the first possible UL slot or sub-slot. Some of the HARQ processes for which the WTRU needs to report feedback may be of lower priority or tied to a service of a less stringent latency requirement. As such, uplink control enhancement such as feedback overhead reduction may be desired.

With multiple active DL SPSs, reporting UCI (e.g., ACK/NACK feedbacks) of all active configuration(s) will increase the uplink overhead. For TDD mode of operation, the amount of resources reserved for uplink transmission(s) may not be able to support high overhead for HARQ-ACK feedbacks. For example, an loT device or WTRU operating in TDD mode may be configured with multiple active DL SPSs for which a HARQ-ACK feedback should be reported. In various embodiments, a feedback overhead reduction procedure/mechanism may be applied for HARQ-ACK feedback for DL SPS transmissions and/or for dynamic scheduled TBs.

In various embodiments, a WTRU may apply feedback overhead reduction (other terms may be used or interchanged, such as UCI payload reduction, UCI overhead reduction, feedback reduction, feedback overhead reduction, or feedback overhead reduction) mechanisms based on any of the following:.

In various embodiments, a WTRU may apply one or more feedback overhead reduction mechanisms to reduce the feedback overhead. The feedback overhead reduction mechanisms may include any of UCI compression, UCI skipping, UCI splitting, and UCI delaying. In various embodiments, UCI compression may comprise HARQ-ACK codebook compression, UCI skipping may comprise HARQ-ACK bit(s) feedback skipping, and UCI delaying may comprise HARQ-ACK feedback delaying.

In various embodiments, a WTRU may apply HARQ-ACK codebook compression. In various embodiments, the HARQ-ACK codebook compression may be carried out using a compression function on a HARQ-ACK codebook having a size of N bits. In various embodiments, the compression function may include calculating an "AND" (logical AND) operation of all or a subset of one or more ACK/NACK bits that belong to the HARQ-ACK codebook. In various embodiments, a WTRU may be configured to calculate the "AND" (logical AND) operation of only a subset of the ACK/NACK bits of the HARQ-ACK codebook. For instance, a WTRU may calculate the "AND" (logical AND) operation of n<NUM> most significant bits of a HARQ-ACK codebook (n<NUM><N) and may transmit <NUM> bit (or multiple bits that less then n<NUM> bits) instead of n<NUM> bits. This mechanism may be beneficial if the detailed ACK/NACKs feedback of only the last set of transmitted PDSCHs (e.g., the last one or more PDSCHs transmitted from the network) is needed. For example, the channel conditions during the first set of PDSCHs transmissions (e.g., the first one or more PDSCHs transmitted from the network) may be similar, therefore only the detailed ACK/NACKs feedback of the last set of transmitted PDSCHs is required.

In various embodiments, a WTRU may calculate the "AND" (logical AND) operation of n<NUM> last (or least) significant bits of a HARQ-ACK codebook (n<NUM><N) and may transmit <NUM> bit (or multiple bits that less then n<NUM> bits) instead of n<NUM> bits. This mechanism may be beneficial if the detailed ACK/NACKs feedback of only the first set of transmitted PDSCHs is needed (e.g., the first one or more PDSCHs transmitted from the network). For example, the channel conditions during the last set of PDSCHs transmissions (e.g., the last one or more PDSCHs transmitted from the network) may be similar, therefore only the detailed ACK/NACKs feedback of the first set of transmitted PDSCHs is required.

In various embodiments, a WTRU may calculate an "AND" (logical AND) operation of each n<NUM> sequence of the N bits. The WTRU may compute [N/n<NUM>] bits to be reported as a HARQ-ACK codebook. In various embodiments, a WTRU may report the "AND" (logical AND) operation of all the ACK/NACK bits of a HARQ-ACK codebook. The number n<NUM> may be configured semi-statically from the network, or dynamically determined based on the number of HARQ-ACK codebook N that to be reduced (e.g., the number of HARQ bits to be reduced). In various embodiments, the number n<NUM> may be a fraction of N (e.g., n1=alpha*N), and N may be dynamically changed, as a result, n<NUM> also may be dynamically changed.

In various embodiments, a WTRU may bundle HARQ feedback for multiple TBs, e.g., based on any of an associated DL resource group and time of assignment. For example, the WTRU may generate a single feedback bit per group/set of PDSCHs or TBs that belong to the same bundle. The WTRU may generate an ACK if all TBs in the bundle were successfully decoded, or NACK if at least one of the TBs in the bundle was not successfully decoded. In various embodiments, a group or set of TBs or a bundle of PDSCHs may be determined by one or more of the following:.

In one embodiment, a WTRU may be configured to apply UCI or HARQ-ACK feedback(s) skipping. In an example, a WTRU may skip (e.g., not report) ACK/NACK bit(s) of some (e.g., one or more) of the scheduled PDSCHs. For example, a WTRU may not transmit a subset of ACK/NACK bits of a HARQ-ACK codebook corresponding to low priority transmissions or one or more HARQ processes which were retransmitted.

In one embodiment, a WTRU may be configured to apply UCI or HARQ-ACK feedback(s) delaying. In an example, a WTRU may postpone the transmission of the ACK/NACK bit of a scheduled PDSCH. The WTRU may postpone the transmission of HARQ-ACK feedback for a subset of HARQ processes, and, for example, transmit the HARQ-ACK feedback in a different slot, sub-slot, and/or a different PUCCH Resource Indication (PRI).

Referring to <FIG>, in one embodiment, a WTRU may be configured to split a HARQ-ACK codebook into multiple sub-codebooks, where some sub-codebooks may not be transmitted, or may be delayed or skipped. The WTRU may determine the HARQ-ACK codebook size for a given UCI transmission based on at least one of the following:.

In various embodiments, a WTRU may be configured to select one or more HARQ-ACK bits for which UCI payload reduction can be applied. In an example, a WTRU may have received N PDSCHs to be reported within a same HARQ-ACK codebook. Based on one or more of the triggers described above, a WTRU may enable UCI payload or HARQ feedback reduction. For example, the WTRU may be configured to apply feedback reduction if at least one PDSCH (e.g., one HARQ-ACK bit) meets any of the following feedback reduction criteria. In an example, the set of PDSCHs for which the feedback being skipped, delayed, or split/compressed may be selected based on one or more of the following:.

In various embodiments, a WTRU may be configured to transmit HARQ-ACK feedback corresponding to a set of PDSCH(s) depending on (at least) whether the UE performs a transmission for other UCI or data in the same slot or sub-slot. For example, HARQ-ACK corresponding to a single or a set of SPS PDSCH(s), or PDSCH(s) without DCI, may be transmitted in a slot or sub-slot if HARQ-ACK corresponding to at least one PDSCH scheduled by DCI is transmitted in the same slot or sub-slot, or if the WTRU transmits PUSCH, CSI, Sounding Reference Signal (SRS), or Scheduling Request (SR) in the same slot or sub-slot, or if at least one HARQ-ACK has a specific value such as NACK (or ACK). Doing this may avoid excessive overhead and interference from PUCCH when the periodicity of SPS is very low and there is no other transmission(s) that would otherwise take place.

In various embodiments, a WTRU may be configured to transmit HARQ-ACK on PUCCH in a slot or sub-slot if at least one of the following conditions is met, and otherwise may not transmit in that slot or sub-slot:.

In various embodiments, a WTRU may be configured with one or more SPS PDSCH configurations. The WTRU may receive an SPS PDSCH activation command and may expect PDSCH transmission in the resources of the SPS PDCSH. In some cases, there may not be a PDSCH transmission in an activated SPS PDSCH resource. As such, it may be beneficial for the WTRU to identify the resources in which SPS PDSCH transmission was skipped.

A WTRU may determine whether an SPS PDSCH resource was used for a transmission. The determination may be performed by at least one of:.

In one embodiment, a WTRU may receive an indication confirming whether a previous SPS PDSCH transmission occasion was used for the transmission of an SPS PDSCH or not. The WTRU may receive a DAl-like signal in each SPS PDSCH. The DAI may cycle through values, and based on the value obtained in an SPS PDSCH, the WTRU may determine if a previous SPS PDSCH transmission was skipped. This may enable the WTRU to differentiate between a skipped SPS PDSCH transmission and a mis-detected SPS PDSCH transmission. In an example, the WTRU may expect the DAI to be incremented only for each actually transmitted SPS PDSCH. For any set of received SPS PDSCH transmissions, the WTRU may determine whether one or more SPS PDSCH transmissions are missing based on the order of received DAI values. In some cases, the DAI may be received as part of the SPS PDSCH transmission or may be received in another signal in resources associated to an SPS PDSCH transmission. The WTRU may determine whether an SPS PDSCH transmission is skipped, or determine the DAI of an SPS PDSCH transmission, based on at least one of the following:.

In one embodiment, a WTRU may receive an indication (e.g., in an SPS PDSCH) of the number of preceding skipped SPS PDSCH transmission(s). In some examples, the indication may be configured to use/apply any procedures discussed herein for a DAI reception.

In one embodiment, a WTRU may receive an indication or a value in a last SPS PDSCH transmission indicating the total number of skipped and/or un-skipped (e.g., SPS PDSCH transmission occasions used for the transmission of a PDSCH) SPS PDSCH transmission(s) in a group of SPS PDSCH transmission occasions. A group of SPS PDSCH transmission occasions may include all the occasions for which the WTRU is expected to report feedback in a same resource. In an example, the indication may be received in the resources of the last un-skipped SPS PDSCH transmission. In another example, the indication may be expected to be received in a pre-determined SPS PDSCH transmission occasion. In this case, the WTRU may receive an indication in a pre-determined (e.g., the last) SPS PDSCH transmission occasion, indicating a set of (or the total number of) skipped and/or un-skipped SPS PDSCH transmission(s) for a group of SPS PDSCH transmission occasions. The WTRU may receive the indication in the pre-determined SPS PDSCH transmission occasion regardless of whether that SPS PDSCH transmission occasion is itself skipped (or un-skipped) for the transmission of an SPS PDSCH.

In various embodiments, a WTRU may receive an activation for one or more SPS PDSCH configurations, but not all the SPS PDSCH transmission occasions may be used for the transmission of an SPS PDSCH (e.g., skipped SPS PDSCH). The WTRU may determine the contents of a HARQ-ACK feedback associated with such an SPS PDSCH as a function of whether or not there are any skipped SPS PDSCH transmissions.

In one embodiment, a WTRU may determine whether to report HARQ-ACK feedback for one or more (skipped or un-skipped) SPS PDSCH transmission occasions (or HARQ Process(es)) based on (e.g., as a function of) at least one of:.

In various embodiments, a WTRU may report / feedback all, or a subset, or none of the HARQ-ACK feedback for SPS or DG PDSCH transmissions. In some cases, this may lead to different HARQ-ACK codebook sizes. To ensure the WTRU and network (e.g., gNB) have common understanding of the HARQ-ACK codebook size(s), the WTRU may receive an indication (e.g., from a gNB) of the expected codebook size prior to a feedback report.

In one embodiment, a WTRU may determine the set of HARQ Processes for which to give feedback (e.g., as per rules described herein). The WTRU may determine the size(s) and content(s) of the HARQ-ACK codebook and may indicate the determined information (e.g., the size(s) and/or content(s)) to the gNB. For example, a HARQ-ACK feedback may include a set of bits indicating the size of the codebook or the contents of the codebook (e.g., NACKs, or ACKs, or skipped PDSCH or SPS PDSCH or DG PDSCH, or any combination thereof).

In one embodiment, a WTRU may determine the number of un-skipped SPS PDSCH transmission(s). The WTRU may use a dynamic codebook (e.g., one that includes feedback for a subset of all the possible SPS PDSCH HARQ Processes), if the WTRU confirms that its determination of number of un-skipped SPS PDSCH is correct (e.g., via signaling from the gNB). The WTRU may use a semi-static codebook, if the WTRU confirms that its determination of the number of un-skipped SPS PDSCH transmission(s) is incorrect.

In various embodiments, a WTRU may be configured to (or predefined to) divide a determined total undivided codebook size (e.g., by legacy rules, for semi-static or dynamic codebook(s)). The WTRU may be configured with a segment size (e.g., n bits). In an example, the WTRU determines the total undivided codebook size (e.g., size N), and may be based on a semi-static or dynamic codebook (e.g., in case of legacy WTRU behavior).

Referring to <FIG>, in one embodiment, a WTRU may be configured to divide the total HARQ codebook into ceil(N/n) segments. In some examples, the WTRU may be configured (or predefined) with a mapping between one or more segment and one or more PRIs. For example, as shown in <FIG>, the WTRU may map the first segment to PRI x, the second segment to PRI x+<NUM>, and so on. The WTRU may transmit codebook segments on one or more PRIs that map to the segment. For example, the WTRU may send the total codebook on n PRIs. The receiver may implicitly determine which codebook segment was transmitted (e.g., the segment index) from the PRI on which the segment is received.

Referring to <FIG>, in one embodiment, a WTRU may be configured to transmit a subset of the codebook segments. The WTRU may decide to skip a subset of n segments, for example, determine not to transmit feedback for the skipped subset of codebook segments. For example, the UE may skip transmitting remaining segments, and/or configure/set the extension bit to <NUM>, if the remaining LSB HARQ-ACK bits are all ACKs or all NACKs. In another example, the WTRU may skip transmission of segments that are all NACKs or all ACKs in general, as the receiver may determine the segment index from a mapped PRI. For each segment, the WTRU may include an extension bit (or a concatenation indication bit), which indicates to the receiver whether more segments are expected or would be skipped for this codebook. The extension bit can also be understood as a termination bit by the receiver, for example, to indicate to the receiver whether the segment is the last transmitted segment or not.

In an example, the extension bit can indicate to the receiver that all previous segments were skipped (e.g., not transmitted), because all HARQ feedback bits are, for instance, all ACKs or all NACKs. In another example, the extension bit can indicate to the receiver that all other segments were skipped (e.g., because all HARQ feedback bits are all ACKs or all NACKs).

In various embodiments, the WTRU may be further configured to bundle or aggregate HARQ feedback per segment to generate a single bit per segment. For example, the WTRU may be configured to generate an ACK bit if all bits in the segment are ACKs, or a NACK bit if at least one bit in the segment is NACK. In this example, the codebook size is determined or defined as n.

In various embodiments, the WTRU may be configured with an association between one or more DL resources or HARQ processes and a physical channel (e.g., PUCCH or PUSCH) and/or certain uplink resources. The WTRU may be configured with an association between one or more DL SPS resources and one or more UL CG. In an example, the WTRU may generate HARQ feedback only on the associated UL resources for feedback reporting.

For example, the WTRU may be configured by RRC signaling with a mapping between SPS resources <NUM> and <NUM> and CG1. For an uplink slot within a TDD frame that contains both CG1 and a PUCCH resource, the WTRU generates HARQ feedback for all HARQ processes associated with DL SPS <NUM> and <NUM> as UCI on PUSCH transmitted on CG1, and generates a HARQ feedback codebook for other processes (e.g., HARQ Process IDs (PIDs) for other SPS resources or other dynamic DL assignments) for transmission on the PUCCH resource(s).

In various embodiments, the WTRU may be configured to indicate the set of transmitted or skipped HARQ-ACK feedback bits by including indices (e.g., within the codebook). In an example, an index may be used (e.g., by the WTRU) to point to a group of HARQ-ACK feedback bits (e.g., a group of HARQ processes). In this example, the granularity with which a WTRU may skip HARQ-ACK feedback bits may depend on the number of elements in each group of HARQ-ACK feedback bits.

In some examples, the HARQ-ACK groups may be configurable. The HARQ-ACK groups may be constructed by the WTRU based on a pre-defined rule. The grouping rule may be defined by at least one of:.

In some cases, the index used by the WTRU to report the HARQ-ACK feedback of a group may identify the elements in the group, and may be determined as a function of the ID(s) of the elements in the group. For example, a WTRU may be configured to provide HARQ-ACK reports only for acknowledged (ACKed) HARQ process(es). In this example, the WTRU may construct a group index as a function of the indices of the processes for which ACK is to be reported. The WTRU may need to only report such group index in the codebook. In another example, the WTRU may be configured to determine two groups, a first group for processes that are associated with ACKs and a second group for processes associated with NACKs. The WTRU may report feedback only for the group with the fewer or fewest elements. The WTRU may construct a group index as a function of the elements of the smaller group and may indicate in the codebook whether that group is for ACK(s) or for NACK(s).

Based on any method or mechanism described herein, the WTRU may not report HARQ-ACK feedback for all its active HARQ processes. As such, the UE may drop the feedback report bits and behave as though it indicated NACK to the network (e.g., gNB).

In one embodiment, the WTRU may keep the feedback report bits and transmit them at a later time. For example, The WTRU may keep the set of unreported feedback bits and may transmit them on a subsequent applicable resource (e.g., a subsequent PUCCH resource).

In another embodiment, the WTRU may create a group (e.g., a PDSCH group) for all the feedback bits that were not (or not yet) transmitted in the expected feedback resource. The WTRU may maintain such a group and may transmit the applicable feedback in a special feedback resource configured for such a group. Alternatively, the WTRU may associate such a group with a pre-configured group ID (e.g., a PDSCH group ID) and may transmit the feedback for the group when triggered by the gNB. The WTRU may expect such a trigger to provide feedback resources, and the trigger may also include the pre-configured group ID.

Referring to <FIG>, in an example, a WTRU is configured with multiple DL SPS configurations, including a set of DL SPS configurations (e.g., a subset of the multiple DL SPS configurations) being activated. The WTRU may determine that the UCI payload is above a pre-configured threshold and/or the number of activated DL SPS (or the set of DL SPS configurations) is above a pre-configured threshold. The WTRU then triggers HARQ codebook segmentation. As shown in <FIG>, for a first sub-codebook, the WTRU may determine to transmit a first subset of HARQ-ACK, for example, HARQ-ACK for TBs of DL SPS(s) with high priority and/or low periodicity. For a second sub-codebook, the WTRU may determine to delay a second subset of HARQ-ACK, for example, HARQ-ACK for TBs of DL SPS(s) with low priority and/or high periodicity. For a third sub-codebook, the WTRU may determine to skip/drop a third subset of HARQ-ACK, for example, HARQ-ACK for TBs of DL SPS(s) that were not transmitted or skipped (e.g., based on condition that DM-RS is not detected).

In various embodiments, method, apparatus, and/or systems for uplink control enhancement (e.g., feedback overhead reduction) in wireless communications are disclosed. In one embodiment, a method (e.g., implemented in WTRU <NUM>) for wireless communications includes determining, by a WTRU (e.g., WTRU <NUM>), that at least one trigger for performing feedback overhead reduction has been satisfied, and performing, by the WTRU, feedback overhead reduction. In various embodiments, the method may comprise performing feedback overhead reduction which includes compressing, skipping, splitting, and/or delaying transmission of uplink control information (UCI) and/or one or more HARQ feedback bits.

In various embodiments, the trigger (or triggering condition) discussed herein may comprise any of: <NUM>) a HARQ codebook, an UCI payload, or a feedback overhead being above a pre-configured threshold; <NUM>) a number of activated DL SPS transmissions (or activated DL SPS configurations) being above a configured threshold; and/or <NUM>) one or more time-division duplexing (TDD) configurations.

In various embodiments, the trigger (or triggering condition) discussed herein may comprise any of: <NUM>) one or more allocated resources for PUCCH transmission(s) for a HARQ codebook or UCI transmission(s); <NUM>) one or more allocated resources for PUSCH transmission(s) for the HARQ codebook or UCI transmission(s); and/or <NUM>) receiving an indication/message from a network (e.g., a Base Station <NUM>, an eNode-B <NUM>, or a gNB <NUM>).

In various embodiments, the trigger (or triggering condition) discussed herein may comprise any of: <NUM>) receiving a bandwidth part (BWP) configuration; <NUM>) receiving a BWP activation message; <NUM>) receiving a BWP switch command; and/or <NUM>) receiving a Physical Downlink Shared Channel (PDSCH) associated with a different BWP than a currently active BWP.

In various embodiments, the trigger (or triggering condition) discussed herein may comprise any of: <NUM>) determining that the WTRU is reporting HARQ feedback on one or more pre-configured component carriers (CCs); or <NUM>) channel conditions reaching a pre-determined level or one or more criteria; or <NUM>) determining that at least one PDSCH or a HARQ-ACK bit meets a feedback reduction criterion; or <NUM>) determining that the WTRU has an ongoing L2 or L3 procedure.

In various embodiments, the method may include compressing the UCI or the HARQ feedback and calculating a logical "AND" operation of all (or a subset) of HARQ feedback bits that belong to a HARQ codebook having a size of N bits. In various embodiments, the method may include skipping one or more HARQ feedback bits of scheduled PDSCH or DM-RS transmissions. In various embodiments, the method may include delaying transmission of HARQ-ACK feedback for a subset of HARQ processes. In various embodiments, when delaying the UCI or the HARQ feedback, the method may further comprise transmitting the HARQ-ACK feedback in a different slot, sub-slot, and/or a different PUCCH Resource Indication (PRI).

In various embodiments, the method may include performing feedback overhead reduction including selecting one or more HARQ feedback bits for which feedback overhead reduction is to be applied.

In various embodiments, a method (e.g., implemented in WTRU <NUM>) for wireless communications may comprise receiving information related to a set of downlink SPS configurations, receiving one or more downlink SPS transmissions based on the received information. The method may also comprise determining a payload of UCI for a transmission over an uplink channel, and the payload comprises a set of HARQ feedback bits based on the received information, determining that at least a triggering condition for segmenting the set of HARQ feedback bits is satisfied, determining at least a portion of the set of HARQ feedback bits based on at least a downlink SPS configuration of the set of downlink SPS configurations, and the portion of the set of HARQ feedback bits corresponds to a portion of the received one or more downlink SPS transmissions. The method may further comprise transmitting at least the portion of the set of HARQ feedback bits using the uplink channel.

In various embodiments, the received information (e.g., received via DCI or RRC signaling) may comprise an indication to activate one or more downlink SPS transmissions (and/or downlink SPS configurations) using at least the downlink SPS configuration of the set of downlink SPS configurations.

In various embodiments, the triggering condition (or trigger) (e.g., for segmenting a set of HARQ feedback bits) discussed herein may comprise any of: <NUM>) determining that a size (e.g., a size of N bits) of the payload of UCI is greater than or equal to a first pre-configured threshold; <NUM>) determining that a number of the activated one or more downlink SPS transmissions is greater than or equal to a second pre-configured threshold; <NUM>) receiving a BWP configuration; <NUM>) receiving a BWP activation message; <NUM>) receiving a BWP switch command; or <NUM>) receiving a PDSCH or DM-RS transmission associated with a different BWP than a currently active BWP.

In various embodiments, a downlink SPS configuration discussed herein may indicate at least a priority or a periodicity of the activated one or more downlink SPS transmissions.

In various embodiments, the method may further comprise determining a first subset and a second subset of the set of HARQ feedback bits, wherein the first subset is associated with a first downlink SPS configuration of the set of downlink SPS configurations, the second subset is associated with a second downlink SPS configuration of the set of downlink SPS configurations, and the portion of the set of HARQ feedback bits comprises any of the first subset or the second subset.

In various embodiments, the method may further comprise determining a first priority associated with the first downlink SPS configuration, determining a second priority associated with the second downlink SPS configuration, and determining the portion of the set of HARQ feedback bits comprising any of the first subset or the second subset of the set of HARQ feedback bits based on at least the first priority and the second priority. In various embodiments, the method may further comprise determining the portion of the set of HARQ feedback bits comprising the first subset of the set of HARQ feedback bits on condition that the first priority is higher than the second priority.

In various embodiments, the method may further comprise delaying transmission of the second subset of the set of HARQ feedback bits on condition that the second priority is lower than the first priority.

In various embodiments, the method may further comprise determining a first periodicity associated with the first downlink SPS configuration, determining a second periodicity associated with the second downlink SPS configuration, and determining the portion of the set of HARQ feedback bits comprising any of the first subset or the second subset based on at least the first periodicity and the second periodicity. In various embodiments, the method may further comprise determining the portion of the set of HARQ feedback bits comprising the first subset on condition that the first periodicity is lower than the second periodicity.

In various embodiments, the method may further comprise delaying transmission of the second subset of the set of HARQ feedback bits on condition that the second periodicity is higher than the first periodicity.

In various embodiments, when delaying transmission of the second subset, the method may further comprise transmitting the second subset of the set of HARQ feedback bits in a different slot, sub-slot, and/or using a different uplink channel.

In various embodiments, the method may further comprise determining a third subset of the set of HARQ feedback bits, and the third subset dose not correspond to any one of the received one or more downlink SPS transmissions. For example, the third subset of HARQ feedback bits may correspond to un-detected DL SPS transmissions such as PDSCH(s) or DM-RS(s). The method may further comprise skipping transmission of the third subset of the set of HARQ feedback bits (e.g., not transmit using allocated uplink control channel resources).

In various embodiments, the uplink channel discussed herein may be a Physical Uplink Control Channel (PUCCH) or a Physical Uplink Shared Channel (PUSCH). In various embodiments, the one or more downlink SPS transmissions discussed herein may comprise at least a Physical Downlink Shared Channel (PDSCH) transmission or a Demodulation Reference Signal (DM-RS) transmission.

In various embodiments, the method may further comprise transmitting, using the portion of the set of HARQ feedback bits, an indication indicating that transmission of another portion of the set of HARQ feedback bits is delayed or skipped. In various embodiments, the method may further comprise transmitting, using an extension bit, an indication indicating that transmission of another portion of the set of HARQ feedback bits is delayed or skipped.

In various embodiments, a method (e.g., implemented in WTRU <NUM>) for wireless communications may comprise receiving one or more downlink SPS transmissions, determining a respective HARQ process ID for each of the received one or more downlink SPS transmissions, determining a set of HARQ feedback bits to be compressed based on the determined HARQ process IDs, and the set of HARQ feedback bits corresponds to at least a portion of the received one or more downlink SPS transmissions, and compressing the set of HARQ feedback bits into one or more bits.

In various embodiments, a method (e.g., implemented in WTRU <NUM>) for wireless communications may comprise receiving information related to a set of downlink SPS configurations, and receiving one or more downlink SPS transmissions based on the received information. The method may further comprise determining a payload of UCI for transmission over an uplink channel, and the payload comprises a set of HARQ feedback bits based on the received information. The method may further comprise determining that at least one triggering condition for segmenting the set of HARQ feedback bits is satisfied, and determining at least a portion of the set of HARQ feedback bits based on at least a downlink SPS configuration of the set of downlink SPS configurations, wherein the determined portion of the set of HARQ feedback bits corresponds to a respective subset of the received one or more downlink SPS transmissions. The method may further comprise transmitting at least the determined portion of the set of HARQ feedback bits using the uplink channel.

In various embodiments, the received information comprises an indication to activate one or more downlink SPS configurations of the set of downlink SPS configurations, and the activated one or more downlink SPS configurations include at least the downlink SPS configuration of the set of downlink SPS configurations. In one embodiment, each of the activated one or more downlink SPS configurations indicates at least a respective priority or a respective periodicity associated with each respective activated downlink SPS configuration.

In various embodiments, the triggering condition (or trigger) (e.g., for segmenting a set of HARQ feedback bits) discussed herein may comprise any of: <NUM>) a determination that a size of the payload of UCI is greater than or equal to a first pre-configured threshold; or <NUM>) a determination that a number of the activated one or more downlink SPS configurations is greater than or equal to a second pre-configured threshold.

In various embodiments, the method may further comprise determining a first subset of HARQ feedback bits and a second subset of HARQ feedback bits of the set of HARQ feedback bits, the first subset is associated with the first downlink SPS configuration, the second subset is associated with a second downlink SPS configuration of the set of downlink SPS configurations, and the determined portion of the set of HARQ feedback bits includes any of the first subset of HARQ feedback bits or the second subset of HARQ feedback bits.

In various embodiments, the method may further comprise determining a first priority associated with the first downlink SPS configuration, determining a second priority associated with the second downlink SPS configuration, and selecting the first subset of HARQ feedback bits or the second subset of HARQ feedback bits to be included in the determined portion of the set of HARQ feedback bits based on any of the first priority or the second priority. In one embodiment, the method may further comprise selecting the first subset of HARQ feedback bits to be included in the determined portion of the set of HARQ feedback bits on condition that the first priority is higher than the second priority. In another embodiment, the method may further comprise transmitting the second subset of HARQ feedback bits in a subsequent transmission opportunity or using a different uplink channel on condition that the second priority is lower than the first priority.

In various embodiments, the method may further comprise determining a first periodicity associated with the first downlink SPS configuration, determining a second periodicity associated with the second downlink SPS configuration, and selecting the first subset of HARQ feedback bits or the second subset of HARQ feedback bits to be included in the determined portion of the set of HARQ feedback bits based on any of the first periodicity or the second periodicity. In one embodiment, the method may further comprise selecting the first subset of HARQ feedback bits to be included in the determined portion of the set of HARQ feedback bits on condition that the first periodicity is lower than the second periodicity. In another embodiment, the method may further comprise transmitting the second subset of HARQ feedback bits in a subsequent transmission opportunity or using a different uplink channel on condition that the second periodicity is higher than the first periodicity.

In various embodiments, the method may further comprise transmitting the first subset of HARQ feedback bits and the second subset of HARQ feedback bits in any of: different slots, different sub-slots, or using different uplink channels.

In various embodiments, the method may further comprise determining a third subset of HARQ feedback bits of the set of HARQ feedback bits, the third subset of HARQ feedback bits does not correspond to any one of the received one or more downlink SPS transmissions, and selecting the third subset of HARQ feedback bits to be included in another portion of the set of HARQ feedback bits.

In various embodiments, the method may further comprise transmitting, using the determined portion of the set of HARQ feedback bits, information to indicate that transmission of another portion of the set of HARQ feedback bits is delayed or skipped. In various embodiments, the method may further comprise transmitting, using an extension bit, information to indicate that transmission of another portion of the set of HARQ feedback bits is delayed or skipped.

In various embodiments, a WTRU (e.g., WTRU <NUM> or a UE) for wireless communications may comprise a receiver (e.g., a transceiver <NUM>, or a transmit/receive element <NUM>) configured to receive (or determine) information related to a set of downlink SPS configurations, and to receive one or more downlink SPS transmissions based on the received information. The WTRU may comprise a processor (e.g., processor <NUM>) configured to: determine a UCI payload for transmission over an uplink channel (e.g., PUCCH or PUSCH), the UCI payload comprises a set of HARQ feedback bits based on the received information; determine that at least one triggering condition for segmenting the set of HARQ feedback bits is satisfied; and determine at least a portion of the set of HARQ feedback bits based on at least a downlink SPS configuration of the set of downlink SPS configurations, the determined portion of the set of HARQ feedback bits corresponds to a respective subset of the received one or more downlink SPS transmissions. The WTRU may also comprise a transmitter (e.g., a transceiver <NUM>, or a transmit/receive element <NUM>) configured to transmit at least the determined portion of the set of HARQ feedback bits using the uplink channel.

In various embodiments, a WTRU (e.g., WTRU <NUM> or a UE) may comprise a processor (e.g., processor <NUM>), a transceiver (e.g., transceiver <NUM>, or a receiver and a transmitter, or a transmit/receive element <NUM>) and memory (e.g., non-removable memory <NUM>, and/or removable memory <NUM>) implementing any of the methods disclosed herein. The WTRU may also comprise any of: a speaker/microphone <NUM>, a keypad <NUM>, a display/touchpad <NUM>, , a power source <NUM>, a global positioning system (GPS) chipset <NUM>, and/or other peripherals <NUM>, among others.

Although features and elements are described above in particular combinations, one of ordinary skill in the art will appreciate that each feature or element can be used alone or in any combination with the other features and elements. In addition, the methods described herein may be implemented in a computer program, software, or firmware incorporated in a computer readable medium for execution by a computer or processor. Examples of non-transitory computer-readable storage media include, but are not limited to, a read only memory (ROM), random access memory (RAM), a register, cache memory, semiconductor memory devices, magnetic media such as internal hard disks and removable disks, magneto-optical media, and optical media such as CD-ROM disks, and digital versatile disks (DVDs). A processor in association with software may be used to implement a radio frequency transceiver for use in a WTRU <NUM>, UE, terminal, base station, RNC, or any host computer.

Moreover, in the embodiments described above, processing platforms, computing systems, controllers, and other devices containing processors are noted. These devices may contain at least one Central Processing Unit ("CPU") and memory. In accordance with the practices of persons skilled in the art of computer programming, reference to acts and symbolic representations of operations or instructions may be performed by the various CPUs and memories. Such acts and operations or instructions may be referred to as being "executed," "computer executed" or "CPU executed.

One of ordinary skill in the art will appreciate that the acts and symbolically represented operations or instructions include the manipulation of electrical signals by the CPU. An electrical system represents data bits that can cause a resulting transformation or reduction of the electrical signals and the maintenance of data bits at memory locations in a memory system to thereby reconfigure or otherwise alter the CPU's operation, as well as other processing of signals. The memory locations where data bits are maintained are physical locations that have particular electrical, magnetic, optical, or organic properties corresponding to or representative of the data bits. It should be understood that the representative embodiments are not limited to the above-mentioned platforms or CPUs and that other platforms and CPUs may support the provided methods.

There is little distinction left between hardware and software implementations of aspects of systems. The use of hardware or software is generally (e.g., but not always, in that in certain contexts the choice between hardware and software may become significant) a design choice representing cost vs. efficiency tradeoffs. There may be various vehicles by which processes and/or systems and/or other technologies described herein may be affected (e.g., hardware, software, and/or firmware), and the preferred vehicle may vary with the context in which the processes and/or systems and/or other technologies are deployed. For example, if an implementer determines that speed and accuracy are paramount, the implementer may opt for a mainly hardware and/or firmware vehicle. If flexibility is paramount, the implementer may opt for a mainly software implementation. Alternatively, the implementer may opt for some combination of hardware, software, and/or firmware.

Although features and elements are provided above in particular combinations, one of ordinary skill in the art will appreciate that each feature or element can be used alone or in any combination with the other features and elements. The present disclosure is not to be limited in terms of the particular embodiments described in this application, which are intended as illustrations of various aspects. Many modifications and variations may be made without departing from its scope, as will be apparent to those skilled in the art. No element, act, or instruction used in the description of the present application should be construed as critical or essential to the invention unless explicitly provided as such. The present disclosure is to be limited only by the terms of the appended claim It is to be understood that this disclosure is not limited to particular methods or systems.

It is also to be understood that the terminology used herein is for the purpose of describing particular embodiments only, and is not intended to be limiting. As used herein, when referred to herein, the terms "station" and its abbreviation "STA", "user equipment" and its abbreviation "UE" may mean (i) a wireless transmit and/or receive unit (WTRU), such as described infra; (ii) any of a number of embodiments of a WTRU, such as described infra; (iii) a wireless-capable and/or wired-capable (e.g., tetherable) device configured with, inter alia, some or all structures and functionality of a WTRU, such as described infra; (iii) a wireless-capable and/or wired-capable device configured with less than all structures and functionality of a WTRU, such as described infra; or (iv) the like. Details of an example WTRU, which may be representative of (or interchangeable with) any UE recited herein, are provided below with respect to <FIG>.

In certain representative embodiments, several portions of the subject matter described herein may be implemented via Application Specific Integrated Circuits (ASICs), Field Programmable Gate Arrays (FPGAs), digital signal processors (DSPs), and/or other integrated formats. However, those skilled in the art will recognize that some aspects of the embodiments disclosed herein, in whole or in part, may be equivalently implemented in integrated circuits, as one or more computer programs running on one or more computers (e.g., as one or more programs running on one or more computer systems), as one or more programs running on one or more processors (e.g., as one or more programs running on one or more microprocessors), as firmware, or as virtually any combination thereof, and that designing the circuitry and/or writing the code for the software and or firmware would be well within the skill of one of skill in the art in light of this disclosure. In addition, those skilled in the art will appreciate that the mechanisms of the subject matter described herein may be distributed as a program product in a variety of forms, and that an illustrative embodiment of the subject matter described herein applies regardless of the particular type of signal bearing medium used to actually carry out the distribution. Examples of a signal bearing medium include, but are not limited to, the following: a recordable type medium such as a floppy disk, a hard disk drive, a CD, a DVD, a digital tape, a computer memory, etc., and a transmission type medium such as a digital and/or an analog communication medium (e.g., a fiber optic cable, a waveguide, a wired communications link, a wireless communication link, etc.).

The herein described subject matter sometimes illustrates different components contained within, or connected with, different other components. It is to be understood that such depicted architectures are merely examples, and that in fact many other architectures may be implemented which achieve the same functionality. In a conceptual sense, any arrangement of components to achieve the same functionality is effectively "associated" such that the desired functionality may be achieved. Hence, any two components herein combined to achieve a particular functionality may be seen as "associated with" each other such that the desired functionality is achieved, irrespective of architectures or intermediate components. Likewise, any two components so associated may also be viewed as being "operably connected", or "operably coupled", to each other to achieve the desired functionality, and any two components capable of being so associated may also be viewed as being "operably couplable" to each other to achieve the desired functionality.

It will be understood by those within the art that, in general, terms used herein, and especially in the appended claims (e.g., bodies of the appended claims) are generally intended as "open" terms (e.g., the term "including" should be interpreted as "including but not limited to," the term "having" should be interpreted as "having at least," the term "includes" should be interpreted as "includes but is not limited to," etc.). It will be further understood by those within the art that if a specific number of an introduced claim recitation is intended, such an intent will be explicitly recited in the claim, and in the absence of such recitation no such intent is present. For example, where only one item is intended, the term "single" or similar language may be used. As an aid to understanding, the following appended claims and/or the descriptions herein may contain usage of the introductory phrases "at least one" and "one or more" to introduce claim recitations. However, the use of such phrases should not be construed to imply that the introduction of a claim recitation by the indefinite articles "a" or "an" limits any particular claim containing such introduced claim recitation to embodiments containing only one such recitation, even when the same claim includes the introductory phrases "one or more" or "at least one" and indefinite articles such as "a" or "an" (e.g., "a" and/or "an" should be interpreted to mean "at least one" or "one or more"). The same holds true for the use of definite articles used to introduce claim recitations. In addition, even if a specific number of an introduced claim recitation is explicitly recited, those skilled in the art will recognize that such recitation should be interpreted to mean at least the recited number (e.g., the bare recitation of "two recitations," without other modifiers, means at least two recitations, or two or more recitations).

Furthermore, in those instances where a convention analogous to "at least one of A, B, and C, etc." is used, in general such a construction is intended in the sense one having skill in the art would understand the convention (e.g., "a system having at least one of A, B, and C" would include but not be limited to systems that have A alone, B alone, C alone, A and B together, A and C together, B and C together, and/or A, B, and C together, etc.). In those instances where a convention analogous to "at least one of A, B, or C, etc." is used, in general such a construction is intended in the sense one having skill in the art would understand the convention (e.g., "a system having at least one of A, B, or C" would include but not be limited to systems that have A alone, B alone, C alone, A and B together, A and C together, B and C together, and/or A, B, and C together, etc.). It will be further understood by those within the art that virtually any disjunctive word and/or phrase presenting two or more alternative terms, whether in the description, claims, or drawings, should be understood to contemplate the possibilities of including one of the terms, either of the terms, or both terms. " Further, the terms "any of" followed by a listing of a plurality of items and/or a plurality of categories of items, as used herein, are intended to include "any of," "any combination of," "any multiple of," and/or "any combination of multiples of" the items and/or the categories of items, individually or in conjunction with other items and/or other categories of items. Moreover, as used herein, the term "set" or "group" is intended to include any number of items, including zero. Additionally, as used herein, the term "number" is intended to include any number, including zero.

As will be understood by one skilled in the art, for any and all purposes, such as in terms of providing a written description, all ranges disclosed herein also encompass any and all possible subranges and combinations of subranges thereof. Any listed range can be easily recognized as sufficiently describing and enabling the same range being broken down into at least equal halves, thirds, quarters, fifths, tenths, etc. As a non-limiting example, each range discussed herein may be readily broken down into a lower third, middle third and upper third, etc. As will also be understood by one skilled in the art all language such as "up to," "at least," "greater than," "less than," and the like includes the number recited and refers to ranges which can be subsequently broken down into subranges as discussed above. Finally, as will be understood by one skilled in the art, a range includes each individual member. Thus, for example, a group having <NUM>-<NUM> cells refers to groups having <NUM>, <NUM>, or <NUM> cells. Similarly, a group having <NUM>-<NUM> cells refers to groups having <NUM>, <NUM>, <NUM>, <NUM>, or <NUM> cells, and so forth.

A processor in association with software may be used to implement a radio frequency transceiver for use in a wireless transmit receive unit (WTRU), user equipment (UE), terminal, base station, Mobility Management Entity (MME) or Evolved Packet Core (EPC), or any host computer. The WTRU may be used m conjunction with modules, implemented in hardware and/or software including a Software Defined Radio (SDR), and other components such as a camera, a video camera module, a videophone, a speakerphone, a vibration device, a speaker, a microphone, a television transceiver, a hands free headset, a keyboard, a Bluetooth® module, a frequency modulated (FM) radio unit, a Near Field Communication (NFC) Module, a liquid crystal display (LCD) display unit, an organic light-emitting diode (OLED) display unit, a digital music player, a media player, a video game player module, an Internet browser, and/or any Wireless Local Area Network (WLAN) or Ultra Wide Band (UWB) module.

Although the invention has been described in terms of communication systems, it is contemplated that the systems may be implemented in software on microprocessors/general purpose computers (not shown). In certain embodiments, one or more of the functions of the various components may be implemented in software that controls a general-purpose computer.

In addition, although the invention is illustrated and described herein with reference to specific embodiments, the invention is not intended to be limited to the details shown. Rather, various modifications may be made in the details within the scope of the claims and without departing from the invention.

Throughout the disclosure, one of skill understands that certain representative embodiments may be used in the alternative or in combination with other representative embodiments.

Although features and elements are described above in particular combinations, one of ordinary skill in the art will appreciate that each feature or element can be used alone or in any combination with the other features and elements. In addition, the methods described herein may be implemented in a computer program, software, or firmware incorporated in a computer readable medium for execution by a computer or processor. Examples of non-transitory computer-readable storage media include, but are not limited to, a read only memory (ROM), random access memory (RAM), a register, cache memory, semiconductor memory devices, magnetic media such as internal hard disks and removable disks, magneto-optical media, and optical media such as CD-ROM disks, and digital versatile disks (DVDs). A processor in association with software may be used to implement a radio frequency transceiver for use in a WRTU, UE, terminal, base station, RNC, or any host computer.

One of ordinary skill in the art will appreciate that the acts and symbolically represented operations or instructions include the manipulation of electrical signals by the CPU. An electrical system represents data bits that can cause a resulting transformation or reduction of the electrical signals and the maintenance of data bits at memory locations in a memory system to thereby reconfigure or otherwise alter the CPU's operation, as well as other processing of signals. The memory locations where data bits are maintained are physical locations that have particular electrical, magnetic, optical, or organic properties corresponding to or representative of the data bits.

The data bits may also be maintained on a computer readable medium including magnetic disks, optical disks, and any other volatile (e.g., Random Access Memory ("RAM")) or non-volatile ("e.g., Read-Only Memory ("ROM")) mass storage system readable by the CPU.

Claim 1:
A method implemented by a wireless transmit/receive unit, WTRU, for wireless communications, the method comprising:
receiving configuration information comprising an indication to activate one or more downlink semi-persistent scheduling, SPS, configurations of a set of downlink SPS configurations;
determining a payload size of uplink control information, UCI, for an uplink transmission, wherein the UCI indicates a set of hybrid automatic repeat request, HARQ, feedback bits associated with one or more downlink transmissions;
determining at least a portion of the set of HARQ feedback bits to be transmitted based on at least one of the payload size of the UCI being greater than or equal to a first threshold or a number of the activated downlink SPS configurations being greater than or equal to a second threshold, wherein at least the portion of the set of HARQ feedback bits is associated with at least one activated downlink SPS configuration and corresponds to a subset of the one or more downlink transmissions; and
transmitting at least the portion of the set of HARQ feedback bits using the uplink transmission.