Patent Description:
Aspects of the present disclosure generally relate to wireless communication and to techniques and apparatuses for uplink hybrid automatic repeat request (HARQ) retransmission scheduling in a network with a large propagation delay.

The 3GPP document "<NPL>, discloses that, in order to avoid HARQ stalling in NTNs with long propagation delays, the gNB can send uplink grants with NDI toggled to a given UE, without waiting for the decoding result of a previous PUSCH transmission using the same HARQ process. In this way, the gNB can dynamically disable retransmissions in selected HARQ processes. These uplink grants arrive to the UE before the RTT from the last PUSCH transmission.

The invention is defined by the attached claims.

Controller/processor <NUM> of base station <NUM>, controller/processor <NUM> of UE <NUM>, and/or any other component(s) of <FIG> may perform one or more techniques associated with uplink hybrid automatic repeat request (HARQ) retransmission scheduling in a network with a large propagation delay, as described in more detail elsewhere herein. For example, controller/processor <NUM> of base station <NUM>, controller/processor <NUM> of UE <NUM>, and/or any other component(s) of <FIG> may perform or direct operations of, for example, process <NUM> of <FIG> and/or other processes as described herein. Memories <NUM> and <NUM> may store data and program codes for base station <NUM> and UE <NUM>, respectively. In some aspects, memory <NUM> and/or memory <NUM> may include a non-transitory computer-readable medium storing one or more instructions (e.g., code and/or program code) for wireless communication. For example, the one or more instructions, when executed (e.g., directly, or after compiling, converting, and/or interpreting) by one or more processors of the base station <NUM> and/or the UE <NUM>, may cause the one or more processors, the UE <NUM>, and/or the base station <NUM> to perform or direct operations of, for example, process <NUM> of <FIG> and/or other processes as described herein. In some aspects, executing instructions may include running the instructions, converting the instructions, compiling the instructions, and/or interpreting the instructions, among other examples.

In some aspects, the UE <NUM> includes means for transmitting, to the base station <NUM>, a first physical uplink shared channel (PUSCH) using one or more physical layer (PHY) parameters associated with a first block error rate (BLER) target performance; means for receiving, from the base station <NUM> prior to expiration of a round trip timer associated with the first PUSCH, downlink control information (DCI) scheduling a second PUSCH and configuring one or more PHY parameters associated with a second BLER target performance; and/or means for transmitting, to the base station <NUM>, the second PUSCH using the one or more PHY parameters associated with the second BLER target performance, wherein the second PUSCH includes a retransmission of the first PUSCH or a new transmission based at least in part on a HARQ process indicated in the DCI. The means for the UE <NUM> to perform operations described herein may include, for example, one or more of antenna <NUM>, demodulator <NUM>, MIMO detector <NUM>, receive processor <NUM>, transmit processor <NUM>, TX MIMO processor <NUM>, modulator <NUM>, controller/processor <NUM>, or memory <NUM>.

In some aspects, the UE <NUM> includes means for receiving, from the base station <NUM>, radio resource control (RRC) signaling indicating one or more HARQ processes to support scheduling a new PUSCH transmission prior to expiration of the round trip timer for a previous transmission; and/or means for determining that the DCI includes an uplink grant for the new transmission based at least in part on the one or more HARQ processes indicated in the RRC signaling including the HARQ process indicated in the DCI.

In some aspects, the UE <NUM> includes means for receiving, from the base station <NUM>, RRC signaling configuring the UE <NUM> to monitor a DCI format used to indicate different PHY parameters prior to expiration of the round trip timer for a previous transmission; and/or means for determining that the DCI configures the one or more PHY parameters associated with the second BLER target performance based at least in part on the DCI received from the base station <NUM> having the DCI format used to indicate different PHY parameters.

In some aspects, the UE <NUM> includes means for receiving, from the base station <NUM>, RRC signaling configuring a bit in the DCI to indicate whether one or more fields in the DCI indicate different PHY parameters prior to expiration of the round trip timer for a previous transmission; and/or means for determining that the DCI configures the one or more PHY parameters associated with the second BLER target performance based at least in part on the bit in the DCI indicating that the one or more fields in the DCI indicate different PHY parameters.

In some aspects, the UE <NUM> includes means for determining that the HARQ process indicated in the DCI received prior to the expiration of the round trip timer is associated with the first PUSCH; and/or means for determining that the DCI includes an uplink grant for the new transmission based at least in part on the base station <NUM> previously scheduling at least one retransmission of the first PUSCH or configuring at least one coverage enhancement for an original transmission of the first PUSCH.

In some aspects, the UE <NUM> includes means for determining that the HARQ process indicated in the DCI received prior to the expiration of the round trip timer is associated with the first PUSCH; and/or means for determining that the DCI includes only an uplink grant for the retransmission of the first PUSCH based at least in part on the base station <NUM> not previously scheduling at least one retransmission of the first PUSCH and not configuring at least one coverage enhancement for an original transmission of the first PUSCH.

In some aspects, the UE <NUM> includes means for determining that the one or more PHY parameters configured in the DCI represent a new set of PHY parameters for the retransmission of the first PUSCH based at least in part on receiving the DCI while the round trip timer is running or while an offset timer delaying a start of the round trip timer is running.

In some aspects, the UE <NUM> includes means for determining that the one or more PHY parameters configured in the DCI represent the one or more PHY parameters associated with the first BLER target performance based at least in part on receiving the DCI while a discontinuous reception retransmission timer is running.

<FIG> is a diagram illustrating an example <NUM> of a regenerative satellite deployment and an example <NUM> of a transparent satellite deployment in a non-terrestrial network.

Example <NUM> shows a regenerative satellite deployment. In example <NUM>, a UE <NUM> is served by a satellite <NUM> via a service link <NUM>. For example, the satellite <NUM> may include a BS <NUM> (e.g., BS 110a) or a gNB. In some aspects, the satellite <NUM> may be referred to as a non-terrestrial base station, a regenerative repeater, and/or an on-board processing repeater, among other examples. In some aspects, the satellite <NUM> may demodulate an uplink radio frequency signal, and may modulate a baseband signal derived from the uplink radio signal to produce a downlink radio frequency transmission. The satellite <NUM> may transmit the downlink radio frequency signal on the service link <NUM>. The satellite <NUM> may provide a cell that covers the UE <NUM>.

Example <NUM> shows a transparent satellite deployment, which may also be referred to as a bent-pipe satellite deployment. In example <NUM>, a UE <NUM> is served by a satellite <NUM> via the service link <NUM>. The satellite <NUM> may be a transparent satellite. The satellite <NUM> may relay a signal received from a gateway <NUM> via a feeder link <NUM>. For example, the satellite <NUM> may receive a radio frequency transmission from the gateway <NUM> via the feeder link <NUM>, and may relay the radio frequency transmission to the UE <NUM> via the service link <NUM> without demodulating the radio frequency transmission. Additionally, or alternatively, the satellite <NUM> may receive a radio frequency transmission from the UE <NUM> via the service link <NUM>, and may relay the radio frequency transmission to the gateway <NUM> via the feeder link <NUM> without demodulating the radio frequency transmission. In some aspects, the satellite <NUM> may frequency convert radio frequency transmissions received on the service link <NUM> to a frequency of the radio frequency transmission on the feeder link <NUM> (or vice versa), and may amplify and/or filter the relayed radio frequency transmission. In some aspects, the UEs <NUM> shown in example <NUM> and example <NUM> may be associated with a Global Navigation Satellite System (GNSS) capability or a Global Positioning System (GPS) capability, though not all UEs have such capabilities. The satellite <NUM> may provide a cell that covers the UE <NUM>.

As shown in <FIG>, the service link <NUM> may include a link between the satellite <NUM> and the UE <NUM>, and may include one or more of an uplink or a downlink. The feeder link <NUM> may include a link between the satellite <NUM> and the gateway <NUM>, and may include one or more of an uplink (e.g., from the UE <NUM> to the gateway <NUM>) or a downlink (e.g., from the gateway <NUM> to the UE <NUM>). As shown in <FIG>, an uplink of the service link <NUM> is indicated by reference number <NUM>-U and a downlink of the service link <NUM> is indicated by reference number <NUM>-D. Similarly, an uplink of the feeder link <NUM> is indicated by reference number <NUM>-U and a downlink of the feeder link <NUM> is indicated by reference number <NUM>-D.

The feeder link <NUM> and the service link <NUM> may each experience Doppler effects due to the movement of the satellites <NUM> and <NUM>, and potentially movement of a UE <NUM>. The Doppler effects may be significantly larger than in a terrestrial network. The Doppler effect on the feeder link <NUM> may be compensated for to some degree, but may still be associated with some amount of uncompensated frequency error. Furthermore, the gateway <NUM> may be associated with a residual frequency error, and/or the satellite <NUM>/<NUM> may be associated with an on-board frequency error. These sources of frequency error may cause a received downlink frequency at the UE <NUM> to drift from a target downlink frequency. Furthermore, due to the long distance between the UE <NUM> and satellite <NUM>/<NUM>, communication in a non-terrestrial network may be associated with a much longer delay (e.g., longer latency and/or round trip time) than a terrestrial network. The delay may be even greater in a transparent satellite deployment, as any communication between the UE <NUM> and the gateway <NUM> must travel over the service link <NUM> and the feeder link <NUM>, each of which may associated with a longer delay than a terrestrial network. The large propagation delay in a non-terrestrial network may pose various challenges, including how to schedule uplink HARQ retransmissions before a decoding result is known for a previous uplink transmission.

<FIG> is a diagram illustrating an example <NUM> of DCI including a new transmission grant and an example <NUM> of DCI including a retransmission grant in a network with a large propagation delay (e.g., a non-terrestrial network), in accordance with various aspects of the present disclosure.

As shown in <FIG>, and by example <NUM>, a base station may dynamically disable HARQ retransmission for a first physical uplink shared channel (PUSCH) by transmitting, to a UE, DCI that includes an uplink grant to schedule a new PUSCH (e.g., a new transport block) prior to determining a decoding result for the first PUSCH. For example, the base station may initially transmit, to the UE, DCI that schedules the first PUSCH and indicates one or more physical layer (PHY) parameters to be used for the first PUSCH. The first PUSCH may be associated with a HARQ process that corresponds to a buffer in which the UE stores a corresponding transport block. As shown in <FIG>, after the UE performs an original transmission of the first PUSCH, the UE starts a round trip timer (RTT), which may be restarted if another PUSCH (e.g., a retransmission of the first PUSCH or a new transmission) is transmitted while the round trip timer is running. When the round trip timer expires, the UE may start a discontinuous reception (DRX) retransmission timer, and the UE may expect an uplink grant for a retransmission only while the DRX retransmission timer is running. In other words, the UE generally does not expect any scheduling while the round trip timer is running and prior to starting the DRX retransmission timer. However, in some cases, a wireless network may enable a base station to transmit DCI to schedule a new PUSCH transmission while the round trip timer associated with a HARQ process is running (e.g., to enable earlier transmission of a new transport block), which dynamically disables retransmission of the first PUSCH associated with the HARQ process.

Accordingly, problems may arise in cases where the base station transmits DCI to the UE to schedule a new PUSCH associated with the same HARQ process as the first PUSCH in a network with a large propagation delay, as the new PUSCH may be scheduled before the base station receives the first PUSCH and/or determines whether the first PUSCH is successfully decoded. For example, when the base station schedules the second PUSCH with the same HARQ process as the first PUSCH, retransmission of the first PUSCH is disabled because the transport block carried in the first PUSCH is flushed from the buffer corresponding to the HARQ process and replaced with the transport block to be carried in the second PUSCH. As a result, the first PUSCH would be lost in cases where the base station does not receive and/or fails to successfully decode the first PUSCH, which is particularly undesirable for high-priority uplink traffic (e.g., a radio resource control (RRC) message).

Furthermore, in cases where the base station transmits DCI that includes a retransmission grant for the first PUSCH after the DRX retransmission timer has started, the UE retransmits the second PUSCH because the transport block of the second PUSCH is stored in the buffer corresponding to the HARQ process of the retransmission grant even though the base station expects a retransmission of the first PUSCH. Additionally, or alternatively, if the DCI scheduling the original transmission of the second PUSCH is lost (e.g., not received and/or unsuccessfully decoded by the UE), a retransmission grant for the HARQ process shared by the first PUSCH and the second PUSCH may cause the UE to retransmit the first PUSCH even though the base station expects a retransmission of the second PUSCH.

Furthermore, in some cases, the base station may indicate a different physical layer (PHY) configuration for the first PUSCH and the second PUSCH when transmitting the DCI to schedule the second PUSCH as a new transmission. For example, as described above, transmitting the DCI to schedule the second PUSCH using the same HARQ process as the first PUSCH disables retransmission of the first PUSCH, which may occur in cases where one or more reliability and/or coverage enhancements are enabled for the first PUSCH (e.g., slot aggregation with multiple repetitions, frequency hopping, and/or high transmission power, among other examples). However, a different (e.g., less reliable) PHY configuration may be indicated for the second PUSCH because HARQ retransmission for the second PUSCH can be scheduled after the DRX retransmission has started. Accordingly, in some cases, a block error rate (BLER) target performance for the first PUSCH may differ from a BLER target performance for the second PUSCH, whereby the DCI used to schedule the original transmission of the second PUSCH may indicate a different PHY configuration than the first PUSCH. However, existing DCI formats generally lack a capability to indicate that a scheduling DCI for a particular HARQ process indicates a new PHY configuration.

Accordingly, in cases where the UE receives DCI scheduling a PUSCH for a new transmission associated with a HARQ process (e.g., the DCI includes an uplink grant with a new data indicator (NDI) bit toggled) before the round trip timer has expired for a previous PUSCH associated with the same HARQ process, the UE may be unable to determine whether the DCI dynamically disables retransmission of the previous PUSCH. Furthermore, in cases where the base station dynamically disables HARQ retransmission for the previous PUSCH (e.g., the base station schedules a new PUSCH transmission in a HARQ process before determining a decoding result for a previous PUSCH transmission in the same HARQ process), the base station may need to inform the UE as to whether the PHY configuration to be used for the new PUSCH transmission is different from the previous PUSCH transmission (e.g., is associated with different power control parameters such as a loop index, a different MCS table, a different DMRS configuration, a different time domain allocation, a different frequency hopping configuration, and/or a different slot aggregation configuration, among other examples). However, as mentioned above, existing signaling techniques lack a capability to indicate whether a base station intends to disable HARQ retransmission for a PUSCH transmission associated with a HARQ process before determining a decoding result for the PUSCH transmission and/or to indicate a different PHY configuration for a new PUSCH transmission when disabling HARQ retransmission for a PUSCH transmission associated with a HARQ process.

Furthermore, the inability to indicate a different PHY configuration in DCI before a decoding result is determined for a PUSCH transmission associated with a HARQ process may cause similar problems when the base station needs to schedule a PUSCH retransmission with different PHY parameters after the round trip timer has expired for a HARQ process. For example, as shown by example <NUM>, the base station may schedule a first PUSCH transmission (PUSCH-<NUM>) and may schedule a retransmission of the first PUSCH transmission before receiving and/or decoding the original transmission of the first PUSCH. In such cases, if the base station fails to receive and successfully decode both the original transmission and the retransmission of the first PUSCH, the base station may schedule a second retransmission of the first PUSCH after the round trip timer has expired (e.g., after the DRX retransmission timer has started for the first PUSCH). In this case, the base station may need to indicate a different PHY configuration for the second retransmission relative to the first retransmission (e.g., a higher uplink power and/or a more reliable MCS, among other examples) to increase a probability of the base station receiving and decoding the first PUSCH. However, a DCI format used to schedule the first retransmission may be the same as the DCI format used to schedule the second retransmission, whereby the base station may be unable to indicate, and the UE may be unable to determine, a different PHY configuration to be used for the second retransmission (e.g., a PHY configuration to achieve a lower BLER target for the second retransmission).

Some aspects described herein relate to techniques and apparatuses to schedule, configure, or otherwise use an uplink HARQ process that supports a new HARQ transmission (e.g., a PUSCH carrying a new transport block) prior to a base station determining a decoding result for a previous PUSCH transmission in the same HARQ process. For example, as will be described in more detail below with reference to <FIG>, a UE may transmit a first PUSCH to a base station using one or more PHY parameters associated with a first BLER target performance for a HARQ process. In cases where the UE receives DCI scheduling a second PUSCH from the base station prior to expiration of a round trip timer associated with the first PUSCH, the UE may determine one or more PHY parameters associated with a second BLER target performance for the HARQ process based on the DCI. The UE may then transmit, to the base station, the second PUSCH using the PHY parameter(s) associated with the second BLER target performance, which may be the same or different than the PHY parameter(s) associated with the first BLER target performance. Furthermore, as described herein, the second PUSCH may be a retransmission of the first PUSCH associated with the HARQ process or a new transmission in the same HARQ process.

<FIG> is a diagram illustrating an example <NUM> associated with uplink HARQ retransmission scheduling in a network with a large propagation delay, in accordance with various aspects of the present disclosure. As shown in <FIG>, example <NUM> includes communication between a base station (e.g., base station <NUM>) and a UE (e.g., UE <NUM>). In some aspects, the base station and the UE may be included in a wireless network (e.g., wireless network <NUM>) with a large propagation delay, such as a non-terrestrial network. In some aspects, the base station and the UE may communicate via a wireless access link, which may include an uplink and a downlink. Additionally, or alternatively, the base station and the UE may communicate using a wireless access link and a wireless feeder link (e.g., via a transparent satellite), each of which may include an uplink and a downlink.

As shown in <FIG>, and by reference number <NUM>, the base station may transmit, and the UE may receive, RRC signaling that indicates uplink HARQ retransmission configuration information. For example, the uplink HARQ retransmission configuration information may enable the base station to transmit DCI that includes an uplink grant associated with a HARQ process before determining a decoding result for a previous PUSCH associated with the same HARQ process (e.g., to schedule a new PUSCH in the same HARQ process and thereby disable HARQ retransmission for the previous PUSCH and/or to indicate a PHY configuration for a new PUSCH and/or a retransmission of the previous PUSCH).

For example, in some aspects, the RRC signaling may indicate one or more HARQ processes that are configured to support scheduling a new PUSCH transmission before a round trip timer has expired for a previous PUSCH (e.g., the base station can transmit DCI that includes an uplink grant to schedule a new PUSCH in the one or more HARQ processes before determining a decoding result of the previous PUSCH transmission associated with the same HARQ process). For example, a wireless network may support a maximum quantity (e.g., up to eight (<NUM>)) HARQ processes that are each associated with a separate buffer, and the RRC signaling may indicate one or more of the HARQ processes that support an uplink grant to schedule a new PUSCH prior to expiration of a round trip timer for a previous PUSCH associated with the one or more HARQ processes (e.g., HARQ processes in which retransmission can be dynamically disabled by scheduling a new PUSCH before the round trip timer has expired for the previous PUSCH associated with the HARQ process). Furthermore, when the UE receives an uplink grant associated with a HARQ process that supports a new transmission uplink grant prior to expiration of a round trip timer for a previous PUSCH associated with the HARQ process, DCI carrying the uplink grant may indicate a new BLER target performance for the new transmission uplink grant. For example, in some aspects, the DCI may indicate a different PHY configuration to meet the new BLER target performance, such as different power control parameters, a different MCS table, a different DMRS configuration, a different time domain allocation, a different frequency hopping configuration, and/or a different slot aggregation configuration.

Additionally, or alternatively, the RRC signaling may configure the UE to monitor a DCI format that is used to indicate that one or more fields in the DCI indicate a change to one or more PHY parameters (e.g., a different MCS table or uplink power control) for a new target BLER performance. For example, base stations that are deployed in a wireless network and/or UEs served by the base stations that are deployed in a wireless network may not universally support the DCI format used to indicate a different PHY configuration. Accordingly, in some aspects, the RRC signaling may indicate whether the UE is to monitor the DCI format for a particular HARQ process (e.g., based on whether the base station and/or the UE support the DCI format), which may indicate to the UE whether to expect an uplink grant for a new PUSCH transmission in the same HARQ process as a previous PUSCH transmission before the round trip timer has expired for the previous PUSCH transmission. Additionally, or alternatively, one or more bits in an existing DCI format may be repurposed to indicate that one or more fields in the DCI indicate a change to one or more PHY parameters. For example, in some aspects, one or more bits may be repurposed in a DCI format used for PUSCH scheduling (e.g., DCI format 0_0 or 0_1) and/or a DCI format used to indicate transmit power control commands for uplink transmissions (e.g., DCI format 2_2 or 2_3), among other examples. In this case, the RRC signaling may indicate whether one or more bits in an existing DCI format are repurposed to indicate that fields in the DCI are to be interpreted differently to determine a different PHY configuration when the DCI carries an uplink grant for a HARQ process before the round trip timer has expired for a previous PUSCH associated with the HARQ process.

As further shown in <FIG>, and by reference number <NUM>, the base station may transmit, and the UE may receive, DCI that includes an uplink grant to schedule a first PUSCH transmission for a HARQ process. For example, in some aspects, the uplink grant may indicate a PHY configuration that includes one or more PHY parameters associated with a first BLER target performance for the first PUSCH, which may be an original transport block transmission. In some aspects, the uplink grant may be provided to the UE based at least in part on a scheduling request (SR) transmitted from the UE to the base station and/or a buffer status report (BSR) that indicates that the UE has uplink data available to transmit. For example, the SR and/or BSR may indicate a logical channel group in which the UE has uplink data available to transmit, and the base station may determine the HARQ process in which to provide the uplink grant based at least in part on the logical channel group indicated by the UE. For example, the logical channel group may be associated with a quality of service (QoS) requirement, which the base station may use to determine whether to provide the uplink grant in a HARQ process that supports scheduling a new PUSCH transmission prior to expiration of a round trip timer (e.g., such that HARQ transmission of the PUSCH can be dynamically disabled) or in a different HARQ process.

As further shown in <FIG>, and by reference number <NUM>, the UE may transmit a first PUSCH using one or more PHY parameters associated with a first BLER target performance (e.g., based on the HARQ process and/or one or more fields in the scheduling DCI that indicate the PHY configuration to meet the first BLER target performance). As described in further detail above, the UE may start a round trip timer after transmitting the first PUSCH, and may monitor for one or more DCI messages that may schedule a second PUSCH in the same HARQ process (e.g., a new PUSCH or a retransmission of the first PUSCH) while the round trip timer is running.

As further shown in <FIG>, and by reference number <NUM>, the base station may transmit, and the UE may receive, another DCI message that includes an uplink grant associated with the same HARQ process as the first PUSCH. Furthermore, as described herein, the subsequent DCI message may be received prior to expiration of the round trip timer associated with the first PUSCH and may configure one or more PHY parameters associated with a second BLER target performance, which may be the same as or different from the first BLER target performance for the first PUSCH. Accordingly, as described herein, the UE may apply various rules to determine whether the uplink grant carried in the subsequent DCI is for a new (e.g., original) PUSCH or a retransmission of the earlier PUSCH for which the round trip timer has not expired and to determine the PHY parameters to be used for the PUSCH that is scheduled to be transmitted by the uplink grant carried in the DCI message.

For example, as described above, the UE may generally start a round trip timer after transmitting the first PUSCH, and may expect an uplink grant to configure a new BLER target performance prior to expiration of the round trip timer in cases where the HARQ process associated with the first PUSCH is one of the HARQ processes configured by RRC signaling to support an uplink grant that configures a new BLER target performance. Additionally, or alternatively, the UE may expect the uplink grant to configure a new BLER target performance in cases where the DCI carrying the uplink grant has a specific format associated with indicating different PHY parameters (e.g., to satisfy a particular BLER target performance) and/or one or more bits in the DCI carrying the uplink grant indicate that one or more fields in the DCI are used to indicate different PHY parameters. Furthermore, in some aspects, whether the uplink grant is interpreted as scheduling a new PUSCH (e.g., a new transport block, such that HARQ retransmission of the first PUSCH is dynamically disabled) or scheduling a retransmission of the first PUSCH may depend on the PHY configuration and/or other scheduling parameters associated with the first PUSCH transmission.

For example, when the uplink grant is received for the HARQ process associated with the first PUSCH before the round trip timer has expired for the first PUSCH, the UE may determine that the uplink grant schedules a new PUSCH only in cases where the base station has already scheduled one or more retransmissions for the first PUSCH and/or a coverage enhancement was configured for the previous PUSCH transmission (e.g., slot aggregation, multiple repetitions, frequency hopping, among other examples). For example, in cases where one or more retransmissions for the first PUSCH have already been scheduled and/or a coverage enhancement was configured for the previous PUSCH transmission, the base station is more likely to successfully receive and decode the previous PUSCH transmission and may therefore dynamically disable HARQ retransmission for the previous PUSCH transmission. Accordingly, if the UE determines that the uplink grant is received for the HARQ process associated with the first PUSCH before the round trip timer has expired for the first PUSCH, the UE may determine that the uplink grant is for a new PUSCH transmission if the base station previously scheduled one or more retransmissions for the first PUSCH and/or enabled a coverage enhancement for the previous PUSCH transmission. Otherwise, if the UE determines that one or more retransmissions have not been scheduled for the first PUSCH and that a coverage enhancement was not configured for the previous PUSCH transmission, the UE may expect an uplink grant to include only a retransmission grant for the previous PUSCH transmission associated with the HARQ process while the round trip timer is running (e.g., before the DRX retransmission timer is started) and/or may expect retransmission grants after the DRX retransmission timer is started (e.g., after the round trip timer has expired).

Furthermore, in cases where the uplink grant schedules a retransmission of the first PUSCH, the base station may configure the UE to interpret the PHY configuration indicated in the DCI depending on whether the round trip timer or an offset timer used to delay a start of the round trip timer is running. For example, in cases where the DCI includes an uplink grant to schedule a retransmission of the first PUSCH (e.g., the NDI bit is not toggled), the UE may interpret the PHY configuration indicated in the DCI as representing a new set of PHY parameters to satisfy a different BLER target performance if the DCI is received while the round trip timer or offset timer is running. Otherwise, if the DCI includes an uplink grant to schedule a retransmission of the first PUSCH (e.g., the NDI bit is not toggled) and the round trip timer or offset timer is not running, the UE may interpret the PHY configuration indicated in the DCI as representing an existing set of values for the PHY parameters.

Accordingly, as further shown in <FIG>, and by reference number <NUM>, the UE may transmit a second PUSCH using the PHY configuration indicated in the subsequent DCI. For example, as described above, the DCI may include an uplink grant to schedule the second PUSCH in the same HARQ process as the first PUSCH, and the UE may determine whether the second PUSCH is to be configured as a retransmission of the first PUSCH or a new transmission (e.g., flushing the transport block of the first PUSCH from the HARQ process buffer) based on a PHY configuration for the first PUSCH and/or a time when the DCI is received. Additionally, or alternatively, the second PUSCH may be associated with a second BLER target performance, which may be the same as or different from the first BLER target performance associated with the first PUSCH. In either case, the UE may determine one or more PHY parameters for the second PUSCH to satisfy the second BLER target performance (e.g., based on the HARQ process associated with the first and second PUSCH, one or more fields in the DCI scheduling the second PUSCH, and/or a status of a round trip timer or offset timer that is started after the UE transmits the first PUSCH).

Furthermore, in cases where the base station dynamically disables HARQ retransmission for the first PUSCH by scheduling the second PUSCH as a new transmission before the round trip timer has expired for the first PUSCH, the base station may enable one or more features to enable a quick recovery from a HARQ transmission loss (e.g., failure to receive and/or decode the first PUSCH for which HARQ retransmission was disabled). For example, in cases where HARQ retransmission is disabled, any retransmission needs to be handled at a radio link control (RLC) level. Accordingly, to enable a quick recovery from uplink HARQ transmission failure, the base station may transmit an RLC status report to the UE on a downlink when no retransmission is scheduled or HARQ retransmission is otherwise disabled for a PUSCH that the base station fails to receive and/or decode. In this case, the RLC status report may cause the UE to immediately retransmit the PUSCH that the base station failed to receive and/or decode (e.g., before the transport block is flushed from the buffer associated with the HARQ process). Similarly, for a downlink HARQ transmission failure, the base station may signal the UE to trigger an RLC status report, and the signal to trigger the RLC status report may be piggybacked in the DCI scheduling the PUSCH to cause the UE to transmit the RLC status report.

<FIG> is a diagram illustrating an example process <NUM> performed, for example, by a UE, in accordance with various aspects of the present disclosure. Example process <NUM> is an example where the UE (e.g., UE <NUM>) performs operations associated with uplink HARQ retransmission scheduling in a network with a large propagation delay.

As shown in <FIG>, in some aspects, process <NUM> may include transmitting, to a base station, a first PUSCH using one or more PHY parameters associated with a first BLER target performance (block <NUM>). For example, the UE (e.g., using transmission component <NUM>, depicted in <FIG>) may transmit, to a base station, a first PUSCH using one or more PHY parameters associated with a first BLER target performance, as described above.

As further shown in <FIG>, in some aspects, process <NUM> may include receiving, from the base station prior to expiration of a round trip timer associated with the first PUSCH, DCI scheduling a second PUSCH and configuring one or more PHY parameters associated with a second BLER target performance (block <NUM>). For example, the UE (e.g., using reception component <NUM>, depicted in <FIG>) may receive, from the base station prior to expiration of a round trip timer associated with the first PUSCH, DCI scheduling a second PUSCH and configuring one or more PHY parameters associated with a second BLER target performance, as described above.

As further shown in <FIG>, in some aspects, process <NUM> may include transmitting, to the base station, the second PUSCH using the one or more PHY parameters associated with the second BLER target performance, wherein the second PUSCH includes a retransmission of the first PUSCH or a new transmission based at least in part on a HARQ process indicated in the DCI (block <NUM>). For example, the UE (e.g., using transmission component <NUM>, depicted in <FIG>) may transmit, to the base station, the second PUSCH using the one or more PHY parameters associated with the second BLER target performance, wherein the second PUSCH includes a retransmission of the first PUSCH or a new transmission based at least in part on a HARQ process indicated in the DCI, as described above.

In a first aspect, process <NUM> includes receiving, from the base station, RRC signaling indicating one or more HARQ processes to support scheduling a new PUSCH transmission prior to expiration of the round trip timer for a previous transmission, and determining that the DCI includes an uplink grant for the new transmission based at least in part on the one or more HARQ processes indicated in the RRC signaling including the HARQ process indicated in the DCI.

In a second aspect, alone or in combination with the first aspect, process <NUM> includes receiving, from the base station, RRC signaling configuring the UE to monitor a DCI format used to indicate different PHY parameters prior to expiration of the round trip timer for a previous transmission, and determining that the DCI configures the one or more PHY parameters associated with the second BLER target performance based at least in part on the DCI received from the base station having the DCI format used to indicate different PHY parameters.

In a third aspect, alone or in combination with one or more of the first and second aspects, process <NUM> includes receiving, from the base station, RRC signaling configuring a bit in the DCI to indicate whether one or more fields in the DCI indicate different PHY parameters prior to expiration of the round trip timer for a previous transmission, and determining that the DCI configures the one or more PHY parameters associated with the second BLER target performance based at least in part on the bit in the DCI indicating that the one or more fields in the DCI indicate different PHY parameters.

In a fourth aspect, alone or in combination with one or more of the first through third aspects, process <NUM> includes determining that the HARQ process indicated in the DCI received prior to the expiration of the round trip timer is associated with the first PUSCH, and determining that the DCI includes an uplink grant for the new transmission based at least in part on the base station previously scheduling at least one retransmission of the first PUSCH or configuring at least one coverage enhancement for an original transmission of the first PUSCH.

In a fifth aspect, alone or in combination with one or more of the first through fourth aspects, process <NUM> includes determining that the HARQ process indicated in the DCI received prior to the expiration of the round trip timer is associated with the first PUSCH, and determining that the DCI includes only an uplink grant for the retransmission of the first PUSCH based at least in part on the base station not previously scheduling at least one retransmission of the first PUSCH and not configuring at least one coverage enhancement for an original transmission of the first PUSCH.

In a sixth aspect, alone or in combination with one or more of the first through fifth aspects, process <NUM> includes determining that the one or more PHY parameters configured in the DCI represent a new set of PHY parameters for the retransmission of the first PUSCH based at least in part on receiving the DCI while the round trip timer is running or while an offset timer delaying a start of the round trip timer is running.

In a seventh aspect, alone or in combination with one or more of the first through sixth aspects, process <NUM> includes determining that the one or more PHY parameters configured in the DCI represent the one or more PHY parameters associated with the first BLER target performance based at least in part on receiving the DCI while a DRX retransmission timer is running.

In an eighth aspect, alone or in combination with one or more of the first through seventh aspects, the first BLER target performance is the same as the second BLER target performance.

<FIG> is a block diagram of an example apparatus <NUM> for wireless communication. The apparatus <NUM> may be a UE, or a UE may include the apparatus <NUM>. In some aspects, the apparatus <NUM> includes a reception component <NUM> and a transmission component <NUM>, which may be in communication with one another (for example, via one or more buses and/or one or more other components). As shown, the apparatus <NUM> may communicate with another apparatus <NUM> (such as a UE, a base station, or another wireless communication device) using the reception component <NUM> and the transmission component <NUM>. As further shown, the apparatus <NUM> may include a determination component <NUM>, among other examples.

In some aspects, the apparatus <NUM> may be configured to perform one or more operations described herein in connection with <FIG>. Additionally, or alternatively, the apparatus <NUM> may be configured to perform one or more processes described herein, such as process <NUM> of <FIG>. In some aspects, the apparatus <NUM> and/or one or more components shown in <FIG> may include one or more components of the UE described above in connection with <FIG>. Additionally, or alternatively, one or more components shown in <FIG> may be implemented within one or more components described above in connection with <FIG>. Additionally, or alternatively, one or more components of the set of components may be implemented at least in part as software stored in a memory. For example, a component (or a portion of a component) may be implemented as instructions or code stored in a non-transitory computer-readable medium and executable by a controller or a processor to perform the functions or operations of the component.

The transmission component <NUM> may transmit, to a base station, a first PUSCH using one or more PHY parameters associated with a first BLER target performance. The reception component <NUM> may receive, from the base station prior to expiration of a round trip timer associated with the first PUSCH, DCI scheduling a second PUSCH and configuring one or more PHY parameters associated with a second BLER target performance. The transmission component <NUM> may transmit, to the base station, the second PUSCH using the one or more PHY parameters associated with the second BLER target performance, wherein the second PUSCH includes a retransmission of the first PUSCH or a new transmission based at least in part on a HARQ process indicated in the DCI.

The reception component <NUM> may receive, from the base station, RRC signaling indicating one or more HARQ processes to support scheduling a new PUSCH transmission prior to expiration of the round trip timer for a previous transmission. The determination component <NUM> may determine that the DCI includes an uplink grant for the new transmission based at least in part on the one or more HARQ processes indicated in the RRC signaling including the HARQ process indicated in the DCI.

The reception component <NUM> may receive, from the base station, RRC signaling configuring the UE to monitor a DCI format used to indicate different PHY parameters prior to expiration of the round trip timer for a previous transmission. The determination component <NUM> may determine that the DCI configures the one or more PHY parameters associated with the second BLER target performance based at least in part on the DCI received from the base station having the DCI format used to indicate different PHY parameters.

The reception component <NUM> may receive, from the base station, RRC signaling configuring a bit in the DCI to indicate whether one or more fields in the DCI indicate different PHY parameters prior to expiration of the round trip timer for a previous transmission. The determination component <NUM> may determine that the DCI configures the one or more PHY parameters associated with the second BLER target performance based at least in part on the bit in the DCI indicating that the one or more fields in the DCI indicate different PHY parameters.

The determination component <NUM> may determine that the HARQ process indicated in the DCI received prior to the expiration of the round trip timer is associated with the first PUSCH, and the determination component <NUM> may determine that the DCI includes only an uplink grant for the new transmission based at least in part on the base station previously scheduling at least one retransmission of the first PUSCH or configuring at least one coverage enhancement for an original transmission of the first PUSCH.

The determination component <NUM> may determine that the HARQ process indicated in the DCI received prior to the expiration of the round trip timer is a HARQ process associated with the first PUSCH, and the determination component <NUM> may determine that the DCI includes an uplink grant for the retransmission of the first PUSCH based at least in part on the base station not previously scheduling at least one retransmission of the first PUSCH and not configuring at least one coverage enhancement for an original transmission of the first PUSCH.

The determination component <NUM> may determine that the one or more PHY parameters configured in the DCI represent a new set of PHY parameters for the retransmission of the first PUSCH based at least in part on receiving the DCI while the round trip timer is running or while an offset timer delaying a start of the round trip timer is running.

The determination component <NUM> may determine that the one or more PHY parameters configured in the DCI represent the one or more PHY parameters associated with the first BLER target performance based at least in part on receiving the DCI while a DRX retransmission timer is running.

<FIG> is a block diagram of an example apparatus <NUM> for wireless communication. The apparatus <NUM> may be a base station, or a base station may include the apparatus <NUM>. In some aspects, the apparatus <NUM> includes a reception component <NUM> and a transmission component <NUM>, which may be in communication with one another (for example, via one or more buses and/or one or more other components). As shown, the apparatus <NUM> may communicate with another apparatus <NUM> (such as a UE, a base station, or another wireless communication device) using the reception component <NUM> and the transmission component <NUM>.

In some aspects, the apparatus <NUM> may be configured to perform one or more operations described herein in connection with <FIG>. In some aspects, the apparatus <NUM> and/or one or more components shown in <FIG> may include one or more components of the base station described above in connection with <FIG>. Additionally, or alternatively, one or more components shown in <FIG> may be implemented within one or more components described above in connection with <FIG>. Additionally, or alternatively, one or more components of the set of components may be implemented at least in part as software stored in a memory. For example, a component (or a portion of a component) may be implemented as instructions or code stored in a non-transitory computer-readable medium and executable by a controller or a processor to perform the functions or operations of the component.

In some aspects, the reception component <NUM> may include one or more antennas, a demodulator, a MIMO detector, a receive processor, a controller/processor, a memory, or a combination thereof, of the base station described above in connection with <FIG>.

In some aspects, the transmission component <NUM> may include one or more antennas, a modulator, a transmit MIMO processor, a transmit processor, a controller/processor, a memory, or a combination thereof, of the base station described above in connection with <FIG>.

As an example, "at least one of a, b, or c" is intended to cover a, b, c, a-b, a-c, b-c, and a-b-c, as well as any combination with multiples of the same element (e.g., a-a, a-a-a, a-a-b, a-a-c, a-b-b, a-c-c, b-b, b-b-b, b-b-c, c-c, and c-c-c or any other ordering of a, b, and c).

Claim 1:
A user equipment ,UE,(<NUM>) for wireless communication, comprising:
a memory (<NUM>); and
one or more processors (<NUM>) operatively coupled to the memory, the memory and the one or more processors configured to:
transmit, to a base station (110a), a first physical uplink shared channel, PUSCH, using one or more physical layer, PHY, parameters associated with a first block error rate, BLER, target performance;
receive, from the base station prior to expiration of a round trip timer associated with the first PUSCH, downlink control information, DCI, scheduling a second PUSCH and configuring one or more PHY parameters associated with a second BLER target performance; and
transmit, to the base station, the second PUSCH using the one or more PHY parameters associated with the second BLER target performance, wherein the second PUSCH includes a retransmission of the first PUSCH or a new transmission based at least in part on a hybrid automatic repeat request, HARQ, process indicated in the DCI, wherein the DCI scheduling the second PUSCH refers to the same HARQ process as the first PUSCH.