Patent Description:
<NPL>, relates to a contribution that discuses the potential HARQ enhancements for NR-U operation. <NPL>, relates to a discussion of UL signals and channels for NR-U.

In the following, each of the described methods, apparatuses, examples, and aspects which does not fully correspond to the invention as defined in the claims is thus not according to the invention and is, as well as the whole following description, present for illustration purposes only or to highlight specific aspects or features of the claims.

Aspects of the present disclosure provide apparatus, methods, processing systems, and computer readable mediums for data scheduling in uplink burst.

In certain systems, a user equipment (UE) can be scheduled for multiple transmission occasions. For example, a UE may be scheduled for an uplink burst. An uplink burst may correspond to uplink transmissions in multiple consecutive transmission occasions. In certain systems (e.g., Rel-<NUM><NUM> NR), data, such as high priority data, is transmitted in the earliest available grant. In some cases; however, it may be desirable to place the data in a later transmission occasion than the earliest scheduled grant. For example, the UE may not acquire the channel for the earliest scheduled grant, such as when a listen-before-talk (LBT) procedure fails.

Aspects of the present disclose provide techniques and apparatus for flexible placement of data.

The following description provides examples of data scheduling in communication systems, and is not limiting of the scope, applicability, or examples set forth in the claims.

The techniques described herein may be used for various wireless networks and radio technologies. While aspects may be described herein using terminology commonly associated with <NUM>, <NUM>, and/or new radio (e.g., <NUM> NR) wireless technologies, aspects of the present disclosure can be applied in other generation-based communication systems.

NR access may support various wireless communication services, such as enhanced mobile broadband (eMBB) targeting wide bandwidth, millimeter wave mmW, massive machine type communications MTC (mMTC) targeting non-backward compatible MTC techniques, and/or mission critical targeting ultra-reliable low-latency communications (URLLC).

The electromagnetic spectrum is often subdivided, based on frequency/wavelength, into various classes, bands, channels, etc. In <NUM> NR two initial operating bands have been identified as frequency range designations FR1 (<NUM> - <NUM>) and FR2 (<NUM> - <NUM>). Although a portion of FR1 is greater than <NUM>, FR1 is often referred to (interchangeably) as a "Sub-<NUM>" band in various documents and articles.

NR supports beamforming and beam direction may be dynamically configured.

As shown in <FIG>, the wireless communication network <NUM> may be in communication with a core network <NUM>. The core network <NUM> may in communication with one or more base station (BSs) 110110a-z (each also individually referred to herein as BS <NUM> or collectively as BSs <NUM>) and/or user equipment (UE) 120a-y (each also individually referred to herein as UE <NUM> or collectively as UEs <NUM>) in the wireless communication network <NUM> via one or more interfaces.

The BSs <NUM> communicate with UEs <NUM> in the wireless communication network <NUM>.

According to certain aspects, the BSs <NUM> and UEs <NUM> may be configured for high priority data placement in uplink bursts. As shown in <FIG>, the UE 120a includes a data placement manager <NUM>. The data placement manager <NUM> may be configured to flexibly determine one or more of the transmission occasions for transmitting data, in accordance with aspects of the present disclosure. The BS 110a has a data placement manager <NUM> that may perform complementary operations to those performed by the UE 120a.

At the BS 110a, a transmit processor <NUM> may receive data from a data source <NUM> and control information from a controller/processor <NUM>. 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), etc. The data may be for the physical downlink shared channel (PDSCH), etc. 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).

The processor <NUM> may process (e.g., encode and symbol map) the data and control information to obtain data symbols and control symbols, respectively. The transmit processor <NUM> may 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). A transmit (TX) multiple-input multiple-output (MIMO) processor <NUM> may perform spatial processing (e.g., precoding) on the data symbols, the control symbols, and/or the reference symbols, if applicable, and may provide output symbol streams to the modulators (MODs) 232a-232t. Downlink signals from modulators 232a-232t may be transmitted via the antennas 234a-234t, respectively. At the UE 120a, the antennas 252a-252r may receive the downlink signals from the BS 110a and may provide received signals to the demodulators (DEMODs) in transceivers 254a-254r, respectively. A MIMO detector <NUM> may obtain received symbols from all the demodulators 254a-254r, perform MIMO detection on the received symbols if applicable, and provide detected symbols. A receive processor <NUM> may process (e.g., demodulate, deinterleave, and decode) the detected symbols, provide decoded data for the UE 120a to a data sink <NUM>, and provide decoded control information to a controller/processor <NUM>.

On the uplink, at UE 120a, a transmit processor <NUM> may receive and process data (e.g., for the physical uplink shared channel (PUSCH)) from a data source <NUM> and control information (e.g., for the physical uplink control channel (PUCCH) from the controller/processor <NUM>. The symbols from the transmit processor <NUM> may be precoded by a TX MIMO processor <NUM> if applicable, further processed by the modulators in transceivers 254a-254r (e.g., for SC-FDM, etc.), and transmitted to the BS 110a. At the BS 110a, the uplink signals from the UE 120a may be received by the antennas <NUM>, processed by the modulators <NUM>, detected by a MIMO detector <NUM> if applicable, and further processed by a receive processor <NUM> to obtain decoded data and control information sent by the UE 120a.

Antennas <NUM>, processors <NUM>, <NUM>, <NUM>, and/or controller/processor <NUM> of the UE 120a and/or antennas <NUM>, processors <NUM>, <NUM>, <NUM>, and/or controller/processor <NUM> of the BS 110a may be used to perform the various techniques and methods described herein. As shown in <FIG>, the controller/processor <NUM> of the UE 120a has a data placement manager <NUM> that may be configured for flexible data placement, according to aspects described herein. The controller/processor <NUM> of the BS 110a may have a data placement manager <NUM> that may be configured to perform complementary operations to the operations by the UE 110a, according to aspects described herein. Although shown at the controller/processor, other components of the UE 120a and BS 110a may be used to perform the operations described herein.

Each subframe may include a variable number of slots (e.g., <NUM>, <NUM>, <NUM>, <NUM>, <NUM>,. slots) depending on the SCS. Each slot may include a variable number of symbol periods (e.g., <NUM>, <NUM>, or <NUM> symbols) depending on the SCS.

In NR, a synchronization signal block (SSB) is transmitted. In certain aspects, SSBs may be transmitted in a burst where each SSB in the burst corresponds to a different beam direction for UE-side beam management (e.g., including beam selection and/or beam refinement). The SSB includes a PSS, a SSS, and a two symbol PBCH. The SSB can be transmitted in a fixed slot location, such as the symbols <NUM>-<NUM> as shown in <FIG>. The PBCH carries some basic system information, such as downlink system bandwidth, timing information within radio frame, SS burst set periodicity, system frame number, etc. The SSBs may be organized into SS bursts to support beam sweeping. The SSB can be transmitted up to sixty-four times, for example, with up to sixty-four different beam directions for mmWave. The multiple transmissions of the SSB are referred to as a SS burst set. SSBs in an SS burst set may be transmitted in the same frequency region, while SSBs in different SS bursts sets can be transmitted at different frequency regions.

As discussed above, aspects of the disclosure relate to data placement.

In certain systems, the UE (e.g., UE 120a) is scheduled with multiple transmission occasions. For example, the UE may be scheduled with an uplink burst. The uplink burst may include multiple consecutive transmission occasions. In some examples, such as in new radio unlicensed (NR-U) systems, the UE may be scheduled by a multi-TTI (multiple transmission time interval) grant for the transmission occasions (e.g., via a single downlink control information (DCI)). In some examples, the UE may be scheduled by multiple separate DCIs (e.g., multiple uplink grants) for the transmission occasions. Each transmission occasion may have a fixed association with a HARQ (hybrid automatic repeat request) process, such as with a HARQ process ID (identifier). For example, a grant (e.g., grant-<NUM>) may be associated with a first HARQ process ID (e.g., HARQx), another grant (e.g., grant-<NUM>) may be associated with a second HAR process ID (e.g., HARQX+<NUM>), and so on.

The UE prepares the data, for example, by generating medium access control (MAC) protocol data units (PDUs). Each of the PDUs may be for a HARQ process associated with an UL grant.

In certain systems (e.g., Rel-<NUM><NUM> NR), certain data are transmitted in the earlier grant (e.g., the earliest available grant, such as the soonest TTI of multi-TTI grant). In some examples, high priority data, such as low latency data (e.g., ultra-reliable low-latency (URLLC) data) and/or MAC control element (CE) data is transmitted in an earliest grant. In some examples, the data is placed in the earliest grant according to a logical channel prioritization procedure (e.g., such as the logical channel prioritization procedure in TS <NUM>, Section <NUM>. <NUM> of the 3GPP standards). In an illustrative example, if HARQ process=Y is scheduled earliest, then UE tries to include highest priority data in HARQ process=Y.

In some cases, however, it may be desirable to place the data in a later transmission occasion than the earliest scheduled grant (transmission occasion). For example, in certain systems (such as NR-U), the UE may first contend for access to acquire the channel to transmit the data in a transmission occasion (e.g., a slot), such as by performing a listen-before-talk (LBT) procedure. With LBT, the UE may "sense" the communication channel to find out there is no communications before transmitting on the channel. When the communication channel is a wide bandwidth unlicensed carrier, the "channel sensing" procedure may rely on detecting the energy level on subbands of the communications channel. The LBT parameters, such as type, duration, clear channel assessment (CCA) parameters, and the like, may be configured at the UE by the BS. The LBT procedure may fail for one or more of the transmission occasions and the UE cannot send the data in those transmission occasions. Thus, if the UE places the data in the earliest granted transmission occasions but the UE does not yet have access to the channel (e.g., LBT fails), then the UE may miss transmitting the data.

<FIG> is a block diagram <NUM> illustrating example missed transmission of data due to LBT failure. As shown in <FIG>, slots <NUM>-<NUM> may be scheduled (e.g., indicated by a multi-TTI grant). The UE may place data (e.g., high priority and/or MAC CE data) in the earliest available slot, slot <NUM>, and other data (e.g., "normal" priority data) in the remaining scheduled slots <NUM>-<NUM>. The UE may perform an LBT procedure to acquire the channel for transmitting data. The LBT may fail for slots <NUM> and <NUM>, and pass on slot <NUM>. Thus, the UE may miss transmission of the data in slots <NUM> and <NUM>, and initiate transmission for the slots <NUM>-<NUM>.

The network can schedule retransmission of the failed packets, but it will cause additional delay which may not be acceptable to higher priority and/or low latency packets.

Accordingly, what is needed are techniques and apparatus for flexible data placement.

Aspects of the present disclosure provide techniques and apparatus for high priority data placement in uplink bursts. According to certain aspects, a user equipment (UE) can flexibly determine where to place the data (e.g., in which transmission occasion (TO) to transmit the data). The determination may be based on whether the UE has acquired the channel. The determination may be based on a priority of the data. In some examples, the UE includes data in a latter part of an uplink burst, which may have a higher probability of successful transmission that an earlier part of the uplink burst.

<FIG> is a flow diagram illustrating example operations <NUM> for wireless communication, in accordance with certain aspects of the present disclosure. The operations <NUM> may be performed, for example, by a UE (e.g., such as a UE 120a in the wireless communication network <NUM>). Operations <NUM> may be implemented as software components that are executed and run on one or more processors (e.g., controller/processor <NUM> of <FIG>). Further, the transmission and reception of signals by the UE in operations <NUM> may be enabled, for example, by one or more antennas (e.g., antennas <NUM> of <FIG>). 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/processor <NUM>) obtaining and/or outputting signals.

The operations <NUM> may begin, at <NUM>, by receiving one or more uplink grants scheduling a plurality of transmission occasions for the UE. In some examples, the plurality of transmission occasions is scheduled by one or more multiple transmission time interval (multi-TTI) grants. For example, the UE may receive a single downlink control information (DCI) scheduling multiple consecutive transmission occasions (e.g., multiple consecutive slots). In some examples, the UE may receive multiple DCIs each with an uplink grant. Each grant (and/or each transmission occasion) may be associated with a hybrid automatic repeat request (HARQ) process. For example, the uplink grants and/or transmissions occasions may be associated with a HARQ identifier (ID).

At <NUM>, the UE performs a listen-before-talk (LBT) procedure to attempt to acquire a channel for transmitting data in at least one of the plurality of transmission occasions. For example, the UE may sense the communication channel to determine whether other devices are transmitting on the channel. If other devices are communicating on the channel, the LBT procedure may "fail". When the LBT fails, the UE may not use the transmission occasion for transmission. When the UE senses that the channel is not be used by other devices, then the LBT procedure may "pass" and the UE may transmit in the transmission occasion.

At <NUM>, the UE determines one or more of the transmission occasions to transmit data (e.g., MAC CE, URLLC, high priority data, and/or other data) based, at least in part, on the LBT procedure. For example, the UE may flexibly determine the one or more transmission occasions to transmit the data based on whether the LBT procedure passes or fails for the sensed channel in the transmission occasions.

According to certain aspects, the flexibly determining the one or more transmission occasions includes determining a transmission occasion other than an earliest one of the transmission occasions for transmitting the data (e.g., for transmitting at least MAC CE and/or high priority data). In some examples, the UE can flexibly place the data in any slot associated with a new transport block (TB). For example, retransmission data may not be moved. Thus, the flexibly determining the one or more transmission occasions may include determining any of the one or more transmission occasions that is associated with an initial transmission.

In some examples, the UE can place the high priority data in the earliest transmission occasion (e.g., according to the logical channel prioritization rules), but duplicates the high priority data across different HARQ processes of the grants. For example, the UE can send a repetition of the data in one of the other grants associated with a new TB. Thus, the flexibly determining the one or more transmission occasions can include determining an earliest one of the transmission occasions for transmitting highest priority data and determining another of the transmission occasions for transmitting a repetition of the highest priority data. In some examples, when a single DCI is used to schedule multiple physical uplink shared channel (PUSCH) transmissions, the UE is allowed to map generated transport block(s) internally to different HARQ processes in case of LBT failure(s). For example, the UE may transmit a new TB on any HARQ process in the grants that have the same transport block size (TBS), the same redundancy version (RV), and the new data indicators (NDIs) indicate new transmission.

In some examples, the UE can place data, such as the high priority data, starting at the last transmission occasion in the uplink burst or the last medium access control (MAC) protocol data unit (PDU) transmitted by UE in the uplink burst which is associated with a new TB. For example, the UE can place higher priority data in the later transmission occasions (e.g., if associated with a new transmission) of the uplink burst and low priority data within the earlier portion of uplink burst. In other words, the logical channel prioritization order to process grants may be reversed. Thus, the flexibly determining the one or more transmission occasions can include determining a last one of the plurality of transmission occasions for transmitting highest priority data. The flexibly determining the one or more transmission occasions can include determining the transmission occasions for transmitting the data in ascending order of priority. As shown in an illustrative example in <FIG>, similar to the example shown in <FIG>, the UE may be scheduled in slots <NUM>-<NUM> (e.g., by a multi-TTI grant scheduling uplink transmission occasions) and a LBT procedure may fail for slot <NUM> and slot <NUM>, and the LBT may pass on slot <NUM>. As shown in <FIG>, the UE may place data (e.g., higher priority data and/or MAC CE data) in the last transmission occasion of the multi-TTI grant (e.g., slot <NUM>) and may place the remaining data (e.g., the normal priority data) in the remaining slots (slots <NUM>-<NUM>). Thus, as shown in <FIG>, although the LBT procedure failed for the slots <NUM> and <NUM>, the high priority data is still transmitted because the data was placed in the later transmission occasions.

In some examples, the UE can place data in a transmission occasion (e.g., if associated with new transmission) after the UE acquires the channel (e.g., after LBT success). The UE may also have a processing time (e.g., N transmission occasions or slots) to prepare the data (e.g., to prepare the MAC PDU) after acquiring the channel. The physical layer (PHY) at the UE can indicate in which transmission occasion the MAC layer at the UE should include a MAC CE. The PHY may indicate the transmission occasion where the channel is acquired (e.g., LBT succeeded). Thus, the flexibly determining the one or more transmission occasions can include determining an earliest one of the transmission occasions, after acquiring a channel, for transmitting data. The flexibly determining the one or more transmission occasions can include determining an earliest one of the transmission occasions, after acquiring a channel and after a processing time to prepare the data for transmission, for transmitting data. As shown in an illustrative example in <FIG>, similar to the examples shown in <FIG> and <FIG>, the UE may be scheduled in slots <NUM>-<NUM> (e.g., by a multi-TTI grant scheduling uplink transmission occasions) and a LBT procedure may fail for slot <NUM> and slot <NUM>, and the LBT may pass on slot <NUM>. In the example shown in <FIG>, the UE may have a UE MAC PDU processing time of two slots. As shown in <FIG>, the UE may place data (e.g., higher priority data and/or MAC CE data) in the first transmission occasion of the multi-TTI grant (e.g., slot <NUM>) that occurs two slots (e.g., the MAC PDU processing time) after LBT procedure passes (in slot <NUM>).

As mentioned above, in some cases, the uplink burst is scheduled when the UE is provided with multiple grants that schedule consecutive (e.g., contiguous/sequential/back-to-back) transmission occasions independently. For example, a DCI-<NUM> may schedule slot-<NUM>, DCI-<NUM> schedules slot-<NUM>, and DCI-<NUM> schedules slot-<NUM>, such that UL grants are contiguous. However, in some cases the UE may have prepared the data (e.g., the MAC PDU) before it processes one or more (e.g., a subset) of the DCI/UL grants. For example, the UE may have prepared the MAC PDU after receiving DCI-<NUM> and DCI-<NUM>, but after preparing the MAC PDU the UE processes DCI-<NUM>.

According to certain aspects, the UE may not consider (e.g., can ignore) uplink grants received after data preparation for including high priority data. In the above example, the UE only places high priority data based on grants received from DCI-<NUM> and DCI-<NUM>, but will not consider the grant received from DCI-<NUM> for placing the high priority data. Thus, the flexibly determining the one or more transmission occasions can include ignoring transmission occasions scheduled by the one or more of the DCI received after the data was prepared for transmission.

According to certain aspects, the UE can deconstruct the data (e.g., MAC PDU) already prepared and reconsider high priority data placement based on all the received grants. In the above example, after receiving DCI-<NUM>, the UE will deconstruct the MAC PDU prepared and will again prepare the MAC PDU with high priority data considering grants provided in DCI-<NUM>, DCI-<NUM>, DCI-<NUM>. This deconstruction may not be done if the UE has already gained access to channel and high priority data can be transmitted using the currently prepared MAC PDU. Thus, the flexibly determining the one or more transmission occasions can include deconstructing the prepared data and determining any of the transmission occasions scheduled by any of the DCI for transmission of the data.

In the case of a MAC CE, if the MAC CE is placed at a later transmission occasion in the uplink burst, the MAC CE contents should be prepared according to the transmission occasion used for MAC CE transmission. For example, the buffer status report should not report data corresponding to TBs which have been attempted at earlier transmission occasions of the uplink burst. Thus, a MAC CE transmitted in the determined transmission occasion may include a buffer status report excluding data that was attempted in an earlier of the transmission occasions.

According to certain aspects, the number of transmission occasions that transmission of the data (e.g., of high priority data) can be delayed may be restricted (e.g., capped/limited). For example, if five contiguous slots are available for UL transmission, then the UE may only be able to (e.g., may be restricted/limited to) insert (e.g., place) data up to slot-<NUM>. Delaying the data too long may decrease the quality-of-service (QoS). Thus, the UE may be configured with a maximum number of transmission occasions or slots or time duration that it can delay transmission of data with respect to an earliest of the transmission occasions. Such restriction can be imposed (e.g., configured or signaled) by network. In some examples, the BS can indicate to the UE how many slots can be delayed to transmit a MAC CE and/or a high priority logical channel data. In some examples, the UE decides on its own to limit the acceptable delay in transmission of the data.

In some cases, transmission occasions may be punctured. If the high priority data is placed in the earliest transmission occasion of the uplink burst, but the transmission occasion is punctured, then the network may not be able to successfully decode the data. Instead, the network may only be able to decode the data after the UE performs a HARQ retransmission, which can lead to delay for reception of the data.

According to certain aspects, if puncturing is performed on the transmission occasion where the UE performs transmission, then UE may not include the data (e.g., high priority data) in the punctured transmission occasion. Instead, the UE can include the data in one of later slots based on its processing timeline. Thus, determining the one or more transmission occasions can include ignoring the punctured transmission occasion for transmitting data. According to certain aspects, the UE can place the data in the punctured earliest transmission occasion (e.g., according to the logical channel prioritization rules) and repeat the data in another transmission occasion. This may be done for grants where the HARQ process ID selection is up to the UE. Thus, determining the one or more transmission occasions can include at least one punctured transmission occasion for transmitting data and determining another of the transmission occasions for transmitting a repetition of the data. In some examples, the UE may perform the above procedures-for placing the data in an unpunctured transmission occasion and/or for repeating the data in another transmission occasion-when a threshold number of symbols are punctured in the transmission occasion.

The processing system <NUM> includes a processor <NUM> coupled to a computer-readable medium/memory <NUM> via a bus <NUM>. In certain aspects, the computer-readable medium/memory <NUM> is configured to store instructions (e.g., computer-executable code) that when executed by the processor <NUM>, cause the processor <NUM> to perform the operations illustrated in <FIG>, or other operations for performing the various techniques discussed herein for data scheduling in uplink bursts. In certain aspects, computer-readable medium/memory <NUM> stores code <NUM> for receiving one or more uplink grants scheduling a plurality of transmission occasions for the UE; code <NUM> for performing a LBT procedure to attempt to acquire a channel for transmitting data in at least one of the plurality of transmission occasions; and code <NUM> for determining one or more of the plurality of transmission occasions to transmit data based, at least in part, on the LBT procedure, in accordance with aspects of the present disclosure. In certain aspects, the processor <NUM> has circuitry configured to implement the code stored in the computer-readable medium/memory <NUM>. The processor <NUM> includes circuitry <NUM> for receiving one or more uplink grants scheduling a plurality of transmission occasions for the UE; circuitry <NUM> for performing a LBT procedure to attempt to acquire a channel for transmitting data in at least one of the plurality of transmission occasions; and circuitry <NUM> for determining one or more of the plurality of transmission occasions to transmit data based, at least in part, on the LBT procedure, in accordance with aspects of the present disclosure.

BSs are not the only entities that may function as a scheduling entity.

Claim 1:
A method (<NUM>) for wireless communication by a user equipment, UE, the method (<NUM>) comprising:
receiving (<NUM>) one or more uplink grants scheduling a plurality of transmission occasions for the UE;
performing (<NUM>) a listen-before-talk, LBT, procedure to attempt to acquire a channel for transmitting in at least one of the plurality of transmission occasions;
determining (<NUM>) one or more of the plurality of transmission occasions to transmit data based, at least in part, on the LBT procedure, characterized in that said determining comprising one of:
determining a last one of the plurality of transmission occasions to transmit highest priority data; or
determining transmission occasions to transmit the data in ascending order of a priority of the data, wherein lower priority data is transmitted in earlier transmission occasions than higher priority data.