PROCESSING OF TWO-STAGE DOWNLINK CONTROL INFORMATION

Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a user equipment (UE) may receive first downlink control information (DCI) and second DCI that together schedule a communication of the UE, where the second DCI is received using a default beam or according to a minimum scheduling offset. The UE may transmit or receive the communication based at least in part on the first DCI and the second DCI. Numerous other aspects are provided.

FIELD OF THE DISCLOSURE

Aspects of the present disclosure generally relate to wireless communication and to techniques and apparatuses for processing of two-stage downlink control information (DCI).

BACKGROUND

SUMMARY

In some aspects, a method of wireless communication, performed by a user equipment (UE), may include receiving first downlink control information (DCI) and second DCI that together schedule a communication of the UE, wherein the second DCI is received using a default beam or according to a minimum scheduling offset; and transmitting or receiving the communication based at least in part on the first DCI and the second DCI.

In some aspects, a method of wireless communication, performed by a base station, may include transmitting first DCI and second DCI that together schedule a communication of a UE, wherein the second DCI is transmitted using a default beam or according to a minimum scheduling offset; and transmitting or receiving the communication based at least in part on the first DCI and the second DCI.

In some aspects, a UE for wireless communication may include a memory and one or more processors operatively coupled to the memory. The memory and the one or more processors may be configured to receive first DCI and second DCI that together schedule a communication of the UE, wherein the second DCI is received using a default beam or according to a minimum scheduling offset; and transmit or receive the communication based at least in part on the first DCI and the second DCI.

In some aspects, a base station for wireless communication may include a memory and one or more processors operatively coupled to the memory. The memory and the one or more processors may be configured to transmit first DCI and second DCI that together schedule a communication of a UE, wherein the second DCI is transmitted using a default beam or according to a minimum scheduling offset; and transmit or receive the communication based at least in part on the first DCI and the second DCI.

In some aspects, a non-transitory computer-readable medium may store one or more instructions for wireless communication. The one or more instructions, when executed by one or more processors of a UE, may cause the one or more processors to receive first DCI and second DCI that together schedule a communication of the UE, wherein the second DCI is received using a default beam or according to a minimum scheduling offset; and transmit or receive the communication based at least in part on the first DCI and the second DCI.

In some aspects, a non-transitory computer-readable medium may store one or more instructions for wireless communication. The one or more instructions, when executed by one or more processors of a base station, may cause the one or more processors to transmit first DCI and second DCI that together schedule a communication of a UE, wherein the second DCI is transmitted using a default beam or according to a minimum scheduling offset; and transmit or receive the communication based at least in part on the first DCI and the second DCI.

In some aspects, an apparatus for wireless communication may include means for receiving first DCI and second DCI that together schedule a communication of the apparatus, wherein the second DCI is received using a default beam or according to a minimum scheduling offset; and means for transmitting or receiving the communication based at least in part on the first DCI and the second DCI.

In some aspects, an apparatus for wireless communication may include means for transmitting first DCI and second DCI that together schedule a communication of a UE, wherein the second DCI is transmitted using a default beam or according to a minimum scheduling offset; and means for transmitting or receiving the communication based at least in part on the first DCI and the second DCI.

DETAILED DESCRIPTION

It should be noted that while aspects may be described herein using terminology commonly associated with a 5G or NR radio access technologies (RAT), aspects of the present disclosure can be applied to other RATs, such as a 3G RAT, a 4G RAT, and/or a RAT subsequent to 5G (e.g., 6G).

On the uplink, at UE120, a transmit processor264may receive and process data from a data source262and control information (e.g., for reports that include RSRP, RSSI, RSRQ, CQI, and/or the like) from controller/processor280. Transmit processor264may also generate reference symbols for one or more reference signals. The symbols from transmit processor264may be precoded by a TX MIMO processor266if applicable, further processed by modulators254athrough254r(e.g., for DFT-s-OFDM, CP-OFDM, and/or the like), and transmitted to base station110. In some aspects, the UE120includes a transceiver. The transceiver may include any combination of antenna(s)252, modulators and/or demodulators254, MIMO detector256, receive processor258, transmit processor264, and/or TX MIMO processor266. The transceiver may be used by a processor (e.g., controller/processor280) and memory282to perform aspects of any of the methods described herein, for example, as described with reference toFIGS.4A,4B,5, and6.

In some aspects, UE120may include means for receiving first DCI and second DCI that together schedule a communication of the UE120, where the second DCI is received using a default beam or according to a minimum scheduling offset, means for transmitting or receiving the communication based at least in part on the first DCI and the second DCI, and/or the like. In some aspects, such means may include one or more components of UE120described in connection withFIG.2, such as controller/processor280, transmit processor264, TX MIMO processor266, MOD254, antenna252, DEMOD254, MIMO detector256, receive processor258, and/or the like.

In some aspects, base station110may include means for transmitting first DCI and second DCI that together schedule a communication of a UE, where the second DCI is transmitted using a default beam or according to a minimum scheduling offset, means for transmitting or receiving the communication based at least in part on the first DCI and the second DCI, and/or the like. In some aspects, such means may include one or more components of base station110described in connection withFIG.2, such as antenna234, DEMOD232, MIMO detector236, receive processor238, controller/processor240, transmit processor220, TX MIMO processor230, MOD232, antenna234, and/or the like.

FIG.3is a diagram illustrating an example300of two-stage DCI, in accordance with various aspects of the present disclosure. As shown inFIG.3, two-stage DCI may be used to schedule a physical downlink shared channel (PDSCH) communication or physical uplink shared channel (PUSCH) communication of a UE. A PDSCH communication or a PUSCH communication may be referred to herein as a PxSCH communication.

As shown inFIG.3, a first DCI305(DCI 1) and a second DCI310(DCI 2) may together schedule a PxSCH communication315of a UE. The UE may receive the first DCI305(e.g., a first stage of the two-stage DCI) in a physical downlink control channel (PDCCH) in a control resource set (CORESET). The UE may receive the first DCI305in a first slot (Slot 1). The first DCI305may include scheduling information (e.g., time and frequency information, beam information, and/or the like) for the PxSCH communication315and/or include scheduling information for the second DCI310.

The UE may receive the second DCI310(e.g., a second stage of the two-stage DCI) in a PDSCH (e.g., according to the scheduling information for the second DCI310in the first DCI305). The UE may receive the second DCI310in the first slot (e.g., in the same slot as the first DCI305). The second DCI310also may include scheduling information for the PxSCH communication315.

Accordingly, the scheduling information of the first DCI305and the scheduling information of the second DCI310may together identify scheduling for the PxSCH communication315. The PxSCH communication315may be scheduled in a second slot (Slot 2). That is, the PxSCH communication315may be scheduled in a different slot than the slot in which the first DCI305and the second DCI310are received. Although the example300shows that the PxSCH communication315is scheduled in the second slot, a time location of the PxSCH communication315may be in another slot, such as the first slot (Slot 1).

Wireless networks generally lack support for techniques to process, schedule, or otherwise enable two-stage DCI. In particular, a UE may not be enabled to determine a default beam for receiving second DCI of two-stage DCI, to receive the second DCI according to a minimum scheduling offset, to determine a timeline for processing a PUSCH scheduled by the two-stage DCI, and/or the like. This may increase the complexity associated with processing the two-stage DCI at the UE.

Some techniques and apparatuses described herein enable processing of two-stage DCI. In some aspects, a UE may receive second DCI of two-stage DCI using a default beam or according to a minimum scheduling offset. In some aspects, the UE may process a PUSCH scheduled by two-stage DCI according to a processing timeline. In this way, two-stage DCI may be processed at the UE with reduced complexity, thereby conserving computing resources, memory resources, and/or the like.

FIGS.4A and4Bare diagrams illustrating one or more examples400associated with processing of two-stage DCI, in accordance with various aspects of the present disclosure. As shown inFIGS.4A and4B, example400includes a base station110and a UE120. Although example400shows the UE120receiving two-stage DCI from a single base station110, in some aspects, the UE120may receive the first and second stages of the two-stage DCI from different base stations110, different TRPs (e.g., co-located at the same base station110or located at different base stations110), and/or the like.

As shown inFIG.4A, the base station110may transmit, and the UE120may receive, first DCI (DCI 1)405of two-stage DCI. The UE120may receive the first DCI405in a PDCCH in a CORESET, as described above. As further shown inFIG.4A, the base station110may transmit, and the UE120may receive, second DCI (DCI 2)410of the two-stage DCI. The UE120may receive the second DCI410in a PDSCH, as described above. In some aspects, the first DCI405may include scheduling for the second DCI410. In some aspects, the first DCI405may schedule the second DCI410with a cell radio network temporary identifier (C-RNTI), a configured scheduling RNTI (CS-RNTI), an MCS cell RNTI (MCS-C-RNTI), and/or the like.

The first DCI405and the second DCI410may each include scheduling information for a communication (e.g., a PxSCH communication) of the UE120. That is, the first DCI405and the second DCI410may together schedule the communication. The UE120may receive the second DCI410using a default beam, as illustrated by reference number415, or according to a minimum scheduling offset as illustrated by reference number420. The default beam may be associated with a transmission configuration indicator (TCI) or a quasi co-location (QCL) assumption (e.g., a QCL type D assumption) associated with a reference signal, such as synchronization signal block (SSB), a channel state information reference signal (CSI-RS), a sounding reference signal (SRS), and/or the like.

As shown by reference number415, the UE120may use the default beam to receive the second DCI410when a time offset between receiving the first DCI405and receiving the second DCI410is less than a threshold time duration425(e.g., timeDurationForQCL, as defined in the 3GPP specification). In other words, the UE120may use the default beam to receive the second DCI410during the threshold time duration425after receiving the first DCI405. Accordingly, the UE120may buffer the first DCI405for subsequent decoding after the second DCI410is received. In some aspects, the UE120may use the default beam to receive the second DCI410in a case where TCI identification in DCI is enabled (e.g., tci-PresentInDCI is enabled), or in a case where TCI identification in DCI is not configured (e.g., tci-PresentinDCI is not configured) in radio resource control (RRC) connected mode.

In some aspects, the UE120may determine the default beam that is to be used to receive the second DCI410. For example, the UE120may determine the default beam based at least in part on a QCL assumption associated with a CORESET, such as a CORESET associated with a lowest CORESET identifier (ID) of CORESETs associated with search spaces monitored by the UE120(e.g., in an active bandwidth part (BWP) for the UE120) in the current slot (e.g., the slot in which the first DCI405is received). As an example, the UE120may assume that demodulation reference signal (DM-RS) ports of the PDSCH occasion carrying the second DCI410are quasi co-located with one or more reference signals (RSs) used for PDCCH QCL indication for a CORESET (e.g., a CORESET associated with a monitored search space) associated with a lowest CORESET ID in the current slot.

As shown by reference number415, in the current slot (Slot 1), the UE120may monitor a search space associated with a first CORESET (CORESET 1) that includes the first DCI405, and monitor a search space associated with a second CORESET (CORESET 2) that includes another DCI (DCI A). Moreover, the first CORESET may be associated with a first TCI state and the second CORESET may be associated with a second TCI state. In this example, the UE120may determine that the default beam for receiving the second DCI410is associated with the first TCI state because the first CORESET (CORESET 1) has the lowest CORESET ID among the first CORESET and the second CORESET (CORESET 2).

In this way, for both the cases when tci-PresentInDCI is set to “enabled” and tci-PresentInDCI is not configured in RRC connected mode, if the offset between the reception of the first DCI and second DCI on a PDSCH occasion is less than the threshold timeDurationForQCL, the UE may assume that the DM-RS ports of the PDSCH occasion carrying the second DCI of a serving cell are quasi co-located with the RS(s) with respect to the QCL parameter(s) used for PDCCH quasi co-location indication of the CORESET associated with a monitored search space with the lowest CORESET-ID in the latest slot in which one or more CORESETs within the active BWP of the serving cell are monitored by the UE.

As shown by reference number420, the UE120may receive the second DCI410(e.g., using a C-RNTI, CS-RNTI, or MCS-C-RNTI) according to a minimum scheduling offset430(e.g., as an alternative to using the default beam). The minimum scheduling offset430may be a time offset between reception of the first DCI405and reception of the second DCI410. In some aspects, the UE120may receive the second DCI410according to the minimum scheduling offset430when the minimum scheduling offset430is configured (e.g., RRC configured) for the UE120, or otherwise indicated for the UE120. As an example, if the minimum scheduling offset430is configured for the UE120, then the UE120may determine that the second DCI410is not to be received until after the minimum scheduling offset430following reception of the first DCI405.

In this way, the UE120has sufficient time to decode the first DCI405in order to determine scheduling information for receiving the second DCI410. Accordingly, the first DCI405may schedule the second DCI410using a timing value (e.g., a timing value indicating a timing between a downlink grant included in the first DCI405and reception of a corresponding downlink data communication (e.g., the second DCI410), which may be referred to as a K0value) that satisfies (e.g., is greater than or equal to) the minimum scheduling offset430(which may be referred to as K0min).

In this way, when the minimum scheduling offset restriction is applied, the UE is not expected to be scheduled with a first DCI in slot n and a second DCI on a PDSCH scheduled with C-RNTI, CS-RNTI or MCS-C-RNTI with K0smaller than the applicable minimum scheduling offset restriction K0min. In some aspects, K0minand/or K0may be associated with a time granularity of a slot, an OFDM symbol duration that is determined by a subcarrier spacing, or another time unit.

As described above, the first DCI405and the second DCI410may each include scheduling information for the communication (e.g., the PxSCH communication) of the UE120. Accordingly, the UE120may decode and combine the scheduling information of the first DCI405and the second DCI410in order to determine scheduling for the communication.

As shown inFIG.4B, and by reference number435, the UE120may transmit or receive the communication (e.g., a transport block) scheduled by the first DCI405and the second DCI410. For example, the UE120may receive, from the base station110, the communication in a PDSCH scheduled by the first DCI405and the second DCI410.

As another example, the UE120may transmit, to the base station110, the communication in a PUSCH scheduled by the first DCI405and the second DCI410. In this case, the first DCI405and the second DCI410may schedule the communication after a PUSCH processing time (e.g., a single timeline constraint). In particular, the first DCI405and the second DCI410may indicate a slot offset (e.g., a timing value indicating a timing between an uplink grant indicated by the first DCI405and the second DCI410and transmission of a corresponding uplink data communication (e.g., the communication), which may be referred to as a K2 value) and a start and length indicator value (SLIV) for the communication, and the communication may be associated with a timing advance. Accordingly, the first DCI405and the second DCI410may schedule the communication (e.g., including one or more DM-RSs for the communication) to be transmitted (e.g., according to the slot offset, SLIV, and/or timing advance) starting in a symbol that is after a symbol (which may be referred to as symbol L2) associated with a PUSCH processing time.

In some aspects, as shown by reference number440, a processing time (Tproc2) may be from reception of the last symbol of the PDCCH (e.g., the end of the PDCCH) carrying the first DCI405. Accordingly, the communication may be scheduled to be transmitted starting in a symbol that is after the processing time measured from the end of the PDCCH (e.g., L2 > Tproc2). In some aspects, as shown by reference number445, a processing time (Tproc2′) may be from reception of the last symbol of the PDSCH (e.g., the end of the PDSCH) carrying the second DCI410. Accordingly, the communication may be scheduled to be transmitted starting in a symbol that is after the processing time measured from the end of the PDSCH (e.g., L2 > Tproc2′).

In this way, the UE may transmit the transport block in PUSCH, if the first uplink symbol in the PUSCH allocation for a transport block, including the DM-RS, as defined by the slot offset K2 and the start and length indicator SLIV of the scheduling two-stage DCI and including the effect of the timing advance, starts no earlier than at symbol L2, where L2 is defined as the next uplink symbol with its cyclic prefix (CP) starting after the end of the reception of the last symbol of the PDCCH carrying the first DCI scheduling the PUSCH, or the PDSCH carrying the second DCI scheduling the PUSCH.

In some aspects, the first DCI405and the second DCI410may schedule the communication after a first PUSCH processing time and a second PUSCH processing time (e.g., two timeline constraints). Accordingly, the first DCI405and the second DCI410may schedule the communication (e.g., including one or more DM-RSs for the communication) to be transmitted (e.g., according to the slot offset, SLIV, and/or timing advance) starting in a symbol that is after a symbol (L2) associated with a first PUSCH processing time and after a symbol (which may be referred to as symbol L1) associated with a second PUSCH processing time.

In some aspects, as shown by reference number440, a first processing time (Tproc2) may be from the last symbol of the PDCCH carrying the first DCI405. Accordingly, the communication may be scheduled to be transmitted starting in a symbol that is after the first processing time measured from the end of the PDCCH (e.g., L2 > Tproc2). In some aspects, as shown by reference number445, a second processing time (Tproc1) may be from reception of the last symbol of the PDSCH carrying the second DCI410. Accordingly, the communication also may be scheduled to be transmitted starting in a symbol that is after the second processing time measured from the end of the PDSCH (e.g., L1 > Tproc1).

In this way, the UE may transmit the transport block in PUSCH, if the first uplink symbol in the PUSCH allocation for a transport block, including the DM-RS, as defined by the slot offset K2 and the start and length indicator SLIV of the scheduling two-stage DCI and including the effect of the timing advance, starts no earlier than at symbol L2, where L2 is defined as the next uplink symbol with its CP starting after the end of the reception of the last symbol of the PDCCH carrying the first DCI scheduling the PUSCH, and starts no earlier than at symbol L1, where L1 is defined as the next uplink symbol with its CP starting after the end of the last symbol of the PDSCH carrying the second DCI scheduling the PUSCH.

As indicated above,FIGS.4A and4Bare provided as one or more examples. Other examples may differ from what is described with respect toFIGS.4A and4B.

FIG.5is a diagram illustrating an example process500performed, for example, by a UE, in accordance with various aspects of the present disclosure. Example process500is an example where the UE (e.g., UE120and/or the like) performs operations associated with processing of two-stage DCI.

As shown inFIG.5, in some aspects, process500may include receiving first DCI and second DCI that together schedule a communication of the UE, wherein the second DCI is received using a default beam or according to a minimum scheduling offset (block510). For example, the UE (e.g., using antenna252, DEMOD254, MIMO detector256, receive processor258, controller/processor280, and/or the like) may receive first DCI and second DCI that together schedule a communication of the UE, as described above. In some aspects, the second DCI is received using a default beam or according to a minimum scheduling offset.

As further shown inFIG.5, in some aspects, process500may include transmitting or receiving the communication based at least in part on the first DCI and the second DCI (block520). For example, the UE (e.g., using antenna252, DEMOD254, MIMO detector256, receive processor258, controller/processor280, transmit processor264, TX MIMO processor266, MOD254, and/or the like) may transmit or receive the communication based at least in part on the first DCI and the second DCI, as described above.

In a first aspect, the second DCI is received in a PDSCH.

In a second aspect, alone or in combination with the first aspect, the second DCI is received using the default beam when a time offset between receiving the first DCI and receiving the second DCI does not satisfy a threshold value.

In a third aspect, alone or in combination with one or more of the first and second aspects, process500includes determining the default beam based at least in part on a QCL assumption associated with a CORESET.

In a fourth aspect, alone or in combination with one or more of the first through third aspects, the CORESET is associated with a lowest CORESET identifier of CORESETs associated with search spaces monitored by the UE.

In a fifth aspect, alone or in combination with one or more of the first through fourth aspects, the second DCI is received according to the minimum scheduling offset when the minimum scheduling offset is configured for the UE.

In a sixth aspect, alone or in combination with one or more of the first through fifth aspects, process500includes determining that the second DCI is to be received after the minimum scheduling offset following reception of the first DCI.

In a seventh aspect, alone or in combination with one or more of the first through sixth aspects, the first DCI schedules the second DCI with a timing value that satisfies the minimum scheduling offset.

In an eighth aspect, alone or in combination with one or more of the first through seventh aspects, the communication is transmitted after a processing time from an end of the first DCI.

In a ninth aspect, alone or in combination with one or more of the first through eighth aspects, the communication is transmitted after a processing time from an end of the second DCI.

In a tenth aspect, alone or in combination with one or more of the first through ninth aspects, the communication is transmitted after a first processing time from an end of the first DCI, and after a second processing time from an end of the second DCI.

FIG.6is a diagram illustrating an example process600performed, for example, by a base station, in accordance with various aspects of the present disclosure. Example process600is an example where the base station (e.g., base station110and/or the like) performs operations associated with processing of two-stage DCI.

As shown inFIG.6, in some aspects, process600may include transmitting first DCI and second DCI that together schedule a communication of a UE, wherein the second DCI is transmitted using a default beam or according to a minimum scheduling offset (block610). For example, the base station (e.g., using controller/processor240, transmit processor220, TX MIMO processor230, MOD232, antenna234, and/or the like) may transmit first DCI and second DCI that together schedule a communication of a UE, as described above. In some aspects, the second DCI is transmitted using a default beam or according to a minimum scheduling offset.

As further shown inFIG.6, in some aspects, process600may include transmitting or receiving the communication based at least in part on the first DCI and the second DCI (block620). For example, the base station (e.g., using controller/processor240, transmit processor220, TX MIMO processor230, MOD232, antenna234, DEMOD232, MIMO detector236, receive processor238, and/or the like) may transmit or receive the communication based at least in part on the first DCI and the second DCI, as described above.

In a first aspect, the second DCI is transmitted in a PDSCH.

In a second aspect, alone or in combination with the first aspect, the second DCI is transmitted using the default beam when a time offset between transmitting the first DCI and transmitting the second DCI does not satisfy a threshold value.

In a third aspect, alone or in combination with one or more of the first and second aspects, process600includes determining the default beam based at least in part on a QCL assumption, associated with a CORESET, that is to be used by the UE.

In a fourth aspect, alone or in combination with one or more of the first through third aspects, the CORESET is associated with a lowest CORESET identifier of CORESETs associated with search spaces monitored by the UE.

In a fifth aspect, alone or in combination with one or more of the first through fourth aspects, the second DCI is transmitted according to the minimum scheduling offset when the minimum scheduling offset is configured for the UE.

In a sixth aspect, alone or in combination with one or more of the first through fifth aspects, process600includes determining that the second DCI is to be transmitted after the minimum scheduling offset following transmission of the first DCI.

In a seventh aspect, alone or in combination with one or more of the first through sixth aspects, the first DCI schedules the second DCI with a timing value that satisfies the minimum scheduling offset.

In an eighth aspect, alone or in combination with one or more of the first through seventh aspects, the communication is received after a processing time from an end of the first DCI.

In a ninth aspect, alone or in combination with one or more of the first through eighth aspects, the communication is received after a processing time from an end of the second DCI.

In a tenth aspect, alone or in combination with one or more of the first through ninth aspects, the communication is received after a first processing time from an end of the first DCI, and after a second processing time from an end of the second DCI.

As used herein, the term “component” is intended to be broadly construed as hardware, firmware, and/or a combination of hardware and software. As used herein, a processor is implemented in hardware, firmware, and/or a combination of hardware and software. It will be apparent that systems and/or methods described herein may be implemented in different forms of hardware, firmware, and/or a combination of hardware and software. The actual specialized control hardware or software code used to implement these systems and/or methods is not limiting of the aspects. Thus, the operation and behavior of the systems and/or methods were described herein without reference to specific software code—it being understood that software and hardware can be designed to implement the systems and/or methods based, at least in part, on the description herein.