Patent Description:
Wireless communication systems, as are for example described in <CIT> and <CIT>, are widely deployed to provide various telecommunication services such as telephony, video, data, messaging, and broadcasts.

In some aspects, a method of wireless communication performed by a user equipment (UE) includes: receiving, from a base station, an indication that a plurality of physical downlink shared channel (PDSCH) communications are associated for purposes of demodulation reference signal (DMRS) bundling; determining whether a phase continuity is to be maintained for the plurality of PDSCH communications based at least in part on respective quasi-co-location (QCL) assumptions for the plurality of PDSCH communications; and processing the plurality of PDSCH communications based at least in part on whether the phase continuity is to be maintained.

In some aspects, a method of wireless communication performed by a base station includes: transmitting, to a UE, an indication that a plurality of PDSCH communications are associated for purposes of DMRS bundling; determining whether a phase continuity is to be maintained for the plurality of PDSCH communications based at least in part on respective QCL assumptions for the plurality of PDSCH communications; and transmitting, to the UE, the plurality of PDSCH communications based at least in part on whether the phase continuity is to be maintained.

In some aspects, a UE for wireless communication includes: a memory; and one or more processors operatively coupled to the memory, the memory and the one or more processors configured to: receive, from a base station, an indication that a plurality of PDSCH communications are associated for purposes of DMRS bundling; determine whether a phase continuity is to be maintained for the plurality of PDSCH communications based at least in part on respective QCL assumptions for the plurality of PDSCH communications; and process the plurality of PDSCH communications based at least in part on whether the phase continuity is to be maintained.

In some aspects, a base station for wireless communication includes: a memory; and one or more processors operatively coupled to the memory, the memory and the one or more processors configured to: transmit, to a UE, an indication that a plurality of PDSCH communications are associated for purposes of DMRS bundling; determine whether a phase continuity is to be maintained for the plurality of PDSCH communications based at least in part on respective QCL assumptions for the plurality of PDSCH communications; and transmit, to the UE, the plurality of PDSCH communications based at least in part on whether the phase continuity is to be maintained.

In some aspects, a non-transitory computer-readable medium storing a set of instructions for wireless communication includes: one or more instructions that, when executed by one or more processors of a UE, cause the UE to: receive, from a base station, an indication that a plurality of PDSCH communications are associated for purposes of DMRS bundling; determine whether a phase continuity is to be maintained for the plurality of PDSCH communications based at least in part on respective QCL assumptions for the plurality of PDSCH communications; and process the plurality of PDSCH communications based at least in part on whether the phase continuity is to be maintained.

In some aspects, a non-transitory computer-readable medium storing a set of instructions for wireless communication includes: one or more instructions that, when executed by one or more processors of a base station, cause the base station to: transmit, to a UE, an indication that a plurality of PDSCH communications are associated for purposes of DMRS bundling; determine whether a phase continuity is to be maintained for the plurality of PDSCH communications based at least in part on respective QCL assumptions for the plurality of PDSCH communications; and transmit, to the UE, the plurality of PDSCH communications based at least in part on whether the phase continuity is to be maintained.

In some aspects, an apparatus for wireless communication includes: means for receiving, from a base station, an indication that a plurality of PDSCH communications are associated for purposes of DMRS bundling; means for determining whether a phase continuity is to be maintained for the plurality of PDSCH communications based at least in part on respective QCL assumptions for the plurality of PDSCH communications; and means for processing the plurality of PDSCH communications based at least in part on whether the phase continuity is to be maintained.

In some aspects, an apparatus for wireless communication includes: means for transmitting, to a UE, an indication that a plurality of PDSCH communications are associated for purposes of DMRS bundling; means for determining whether a phase continuity is to be maintained for the plurality of PDSCH communications based at least in part on respective QCL assumptions for the plurality of PDSCH communications; and means for transmitting, to the UE, the plurality of PDSCH communications based at least in part on whether the phase continuity is to be maintained.

Transmit processor <NUM> may also generate reference symbols for reference signals (e.g., a cell-specific reference signal (CRS), a demodulation reference signal (DMRS), and/or the like) and synchronization signals (e.g., the primary synchronization signal (PSS) and secondary synchronization signal (SSS)).

On the uplink, at UE <NUM>, a transmit processor <NUM> may receive and process data from a data source <NUM> and control information (e.g., for reports that include RSRP, RSSI, RSRQ, CQI, and/or the like) from controller/processor <NUM>.

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 phase continuity for demodulation reference signal (DMRS) bundling, 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>, 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, program code, and/or the like) for wireless communication. For example, the one or more instructions, when executed (e.g., directly, or after compiling, converting, interpreting, and/or the like) 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>, 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, interpreting the instructions, and/or the like.

In some aspects, UE <NUM> may include means for receiving (e.g., using antenna <NUM>, DEMOD <NUM>, MIMO detector <NUM>, receive processor <NUM>, controller/processor <NUM>, and/or the like), from a base station, an indication that a plurality of PDSCH communications are associated for purposes of DMRS bundling, means for determining (e.g., using controller/processor <NUM>, memory <NUM>, and/or the like) whether a phase continuity is to be maintained for the plurality of PDSCH communications based at least in part on respective QCL assumptions for the plurality of PDSCH communications, means for processing (e.g., using controller/processor <NUM>, memory <NUM>, and/or the like) the plurality of PDSCH communications based at least in part on whether the phase continuity is to be maintained, and/or the like. In some aspects, such means may include one or more components of UE <NUM> described in connection with <FIG>, such as controller/processor <NUM>, transmit processor <NUM>, TX MIMO processor <NUM>, MOD <NUM>, antenna <NUM>, DEMOD <NUM>, MIMO detector <NUM>, receive processor <NUM>, and/or the like.

In some aspects, base station <NUM> may include means for transmitting (e.g., using controller/processor <NUM>, transmit processor <NUM>, TX MIMO processor <NUM>, MOD <NUM>, antenna <NUM>, and/or the like), to a UE, an indication that a plurality of PDSCH communications are associated for purposes of DMRS bundling, means for determining (e.g., using controller/processor <NUM>, memory <NUM>, and/or the like) whether a phase continuity is to be maintained for the plurality of PDSCH communications based at least in part on respective QCL assumptions for the plurality of PDSCH communications, means for transmitting (e.g., using controller/processor <NUM>, transmit processor <NUM>, TX MIMO processor <NUM>, MOD <NUM>, antenna <NUM>, and/or the like), to the UE, the plurality of PDSCH communications based at least in part on whether the phase continuity is to be maintained, and/or the like. In some aspects, such means may include one or more components of base station <NUM> described in connection with <FIG>, such as antenna <NUM>, DEMOD <NUM>, MIMO detector <NUM>, receive processor <NUM>, controller/processor <NUM>, transmit processor <NUM>, TX MIMO processor <NUM>, MOD <NUM>, antenna <NUM>, and/or the like.

<FIG> is a diagram illustrating an example <NUM> of using beams for communications between a base station and a UE, in accordance with various aspects of the present disclosure. As shown in <FIG>, a base station <NUM> and a UE <NUM> may communicate with one another.

The base station <NUM> may transmit to UEs <NUM> located within a coverage area of the base station <NUM>. The base station <NUM> and the UE <NUM> may be configured for beamformed communications, where the base station <NUM> may transmit in the direction of the UE <NUM> using a directional BS transmit beam, and the UE <NUM> may receive the transmission using a directional UE receive beam. Each BS transmit beam may have an associated beam ID, beam direction, or beam symbols, among other examples. The base station <NUM> may transmit downlink communications via one or more BS transmit beams <NUM>.

The UE <NUM> may attempt to receive downlink transmissions via one or more UE receive beams <NUM>, which may be configured using different beamforming parameters at receive circuitry of the UE <NUM>. The UE <NUM> may identify a particular BS transmit beam <NUM>, shown as BS transmit beam <NUM>-A, and a particular UE receive beam <NUM>, shown as UE receive beam <NUM>-A, that provide relatively favorable performance (for example, that have a best channel quality of the different measured combinations of BS transmit beams <NUM> and UE receive beams <NUM>). In some examples, the UE <NUM> may transmit an indication of which BS transmit beam <NUM> is identified by the UE <NUM> as a preferred BS transmit beam, which the base station <NUM> may select for transmissions to the UE <NUM>. The UE <NUM> may thus attain and maintain a beam pair link (BPL) with the base station <NUM> for downlink communications (for example, a combination of the BS transmit beam <NUM>-A and the UE receive beam <NUM>-A), which may be further refined and maintained in accordance with one or more established beam refinement procedures.

A downlink beam, such as a BS transmit beam <NUM> or a UE receive beam <NUM>, may be associated with a transmission configuration indication (TCI) state. A TCI state may indicate a directionality or a characteristic of the downlink beam, such as one or more QCL properties of the downlink beam. A QCL property may include, for example, a Doppler shift, a Doppler spread, an average delay, a delay spread, or spatial receive parameters, among other examples. In some examples, each BS transmit beam <NUM> may be associated with a synchronization signal block (SSB), and the UE <NUM> may indicate a preferred BS transmit beam <NUM> by transmitting uplink transmissions that are associated with the preferred BS transmit beam <NUM>. A particular SSB may have an associated TCI state (for example, for an antenna port or for beamforming). The base station <NUM> may, in some examples, indicate a downlink BS transmit beam <NUM> based at least in part on antenna port QCL properties that may be indicated by the TCI state. A TCI state may be associated with one downlink reference signal set (for example, an SSB and an aperiodic, periodic, or semi-persistent channel state information reference signal (CSI-RS)) for different QCL types (for example, QCL types for different combinations of Doppler shift, Doppler spread, average delay, delay spread, or spatial receive parameters, among other examples). In cases where the QCL type indicates spatial receive parameters, the QCL type may correspond to analog receive beamforming parameters of a UE receive beam <NUM> at the UE <NUM>. Thus, the UE <NUM> may select a corresponding UE receive beam <NUM> from a set of BPLs based at least in part on the base station <NUM> indicating a BS transmit beam <NUM> via a TCI indication.

A QCL type that indicates Doppler shift, Doppler spread, average delay, and delay spread may be referred to as QCL Type A (or QCL-TypeA). A QCL type that indicates Doppler shift and Doppler spread may be referred to as QCL Type B (or QCL-TypeB). A QCL type that indicates Doppler shift and average delay may be referred to as QCL Type C (or QCL-TypeC). A QCL type that indicates one or more spatial receive (RX) parameters may be referred to as QCL Type D (or QCL-TypeD).

The base station <NUM> may maintain a set of activated TCI states for downlink shared channel transmissions and a set of activated TCI states for downlink control channel transmissions. The set of activated TCI states for downlink shared channel transmissions may correspond to beams that the base station <NUM> uses for downlink transmission on a physical downlink shared channel (PDSCH). The set of activated TCI states for downlink control channel communications may correspond to beams that the base station <NUM> may use for downlink transmission on a physical downlink control channel (PDCCH) or in a control resource set (CORESET). The UE <NUM> may also maintain a set of activated TCI states for receiving the downlink shared channel transmissions and the CORESET transmissions. If a TCI state is activated for the UE <NUM>, then the UE <NUM> may have one or more antenna configurations based at least in part on the TCI state, and the UE <NUM> may not need to reconfigure antennas or antenna weighting configurations. In some examples, the set of activated TCI states (for example, activated PDSCH TCI states and activated CORESET TCI states) for the UE <NUM> may be configured by a configuration message, such as a radio resource control (RRC) message.

The UE <NUM> may use a QCL assumption to determine a beam for receiving a downlink transmission on a PDSCH. The UE <NUM> may determine the QCL assumption based at least in part on an indication in downlink control information (DCI) that schedules the PDSCH. For example, the UE <NUM> may determine the QCL assumption based at least in part on a TCI state indicated in the DCI. In other cases, the UE <NUM> may determine the QCL assumption based at least in part on a default QCL assumption. For example, the UE <NUM> may use a default QCL assumption when a scheduling DCI does not indicate a TCI state, or when a scheduling offset (e.g., a time offset) between a scheduling DCI and a PDSCH scheduled by the DCI does not satisfy a threshold value (e.g., a time duration for QCL value).

Whether the UE <NUM> is to use a TCI state indicated in DCI to determine a QCL assumption for a PDSCH, or use a default QCL assumption for the PDSCH, may be based on several factors. For example, the QCL assumption that is to be used by the UE <NUM> may be based at least in part on whether QCL Type D is configured for PDSCH reception, whether a scheduling offset between reception of the DCI and the scheduled PDSCH satisfies a threshold value, or whether the CORESET that carries the DCI is configured for TCI indication in DCI (e.g., whether TCI being present in DCI is configured). Table <NUM> below indicates the QCL assumption that is to be used for a PDSCH in various scenarios when QCL Type D is configured for PDSCH reception:.

Table <NUM> below indicates the QCL assumption that is to be used for a PDSCH in various scenarios when QCL Type D is not configured for PDSCH reception:.

For uplink communications, the UE <NUM> may transmit in the direction of the base station <NUM> using a directional UE transmit beam, and the base station <NUM> may receive the transmission using a directional BS receive beam. Each UE transmit beam may have an associated beam ID, beam direction, or beam symbols, among other examples. The UE <NUM> may transmit uplink communications via one or more UE transmit beams <NUM>.

The base station <NUM> may receive uplink transmissions via one or more BS receive beams <NUM>. The base station <NUM> may identify a particular UE transmit beam <NUM>, shown as UE transmit beam <NUM>-A, and a particular BS receive beam <NUM>, shown as BS receive beam <NUM>-A, that provide relatively favorable performance (for example, that have a best channel quality of the different measured combinations of UE transmit beams <NUM> and BS receive beams <NUM>). In some examples, the base station <NUM> may transmit an indication of which UE transmit beam <NUM> is identified by the base station <NUM> as a preferred UE transmit beam, which the base station <NUM> may select for transmissions from the UE <NUM>. The UE <NUM> and the base station <NUM> may thus attain and maintain a BPL for uplink communications (for example, a combination of the UE transmit beam <NUM>-A and the BS receive beam <NUM>-A), which may be further refined and maintained in accordance with one or more established beam refinement procedures. An uplink beam, such as a UE transmit beam <NUM> or a BS receive beam <NUM>, may be associated with a spatial relation. A spatial relation may indicate a directionality or a characteristic of the uplink beam, similar to one or more QCL properties, as described above.

<FIG> is a diagram illustrating an example <NUM> of demodulation reference signal (DMRS) bundling, in accordance with various aspects of the present disclosure.

A transmitter, such as a base station, may transmit one or more DMRSs to a receiver, such as a UE. A DMRS may include a reference signal that is generated from a base sequence, such as a Zadoff-Chu sequence or a Gold sequence. The UE may perform one or more measurements of the DMRS to estimate a physical channel on which one or more communications are transmitted from the base station. In this way, the UE may determine whether a channel quality of the physical channel satisfies one or more channel quality thresholds, and may use the results from the one or more measurements to facilitate demodulation of the communications transmitted on the physical channel.

In some cases, the base station may associate or bundle a plurality of time-domain resources (e.g., DMRS symbols) for purposes of DMRS bundling. DMRS bundling permits DMRS symbols for different PDSCH occasions to be transmitted with phase coherence. In this case, the UE may assume that the same precoder is used across the DMRS symbols and that DMRS transmissions across the DMRS symbols may be coherently processed (e.g., coherently combined, coherently filtered, and/or the like) to increase the accuracy of the channel estimation (e.g., by improving a quality of the DMRS).

As shown in <FIG>, DMRS bundling may use a first mode (referred to as Mode <NUM>) or a second mode (referred to as Mode <NUM>). As an example, <FIG> shows PDSCH mapping Type B, a single-symbol DMRS, DMRS Type <NUM>, and two symbols per PDSCH slot.

As shown by reference number <NUM>, Mode <NUM> may use a periodic bundling window. In this case, all DMRS symbols in the bundling window may be bundled. The bundling window may include a configurable quantity of PDSCH occasions or a configurable quantity of slots, and thus, a DMRS bundle may include the DMRS transmissions in the DMRS symbols of the PDSCH occasions or within the slots.

As shown by reference number <NUM>, Mode <NUM> may use dynamic indication (e.g., in a PDCCH) of a DMRS bundle boundary. For example, a base station may transmit, to a UE, an indication of when a new bundle starts or when an ongoing bundle ends (e.g., boundaries of a bundle are dynamically configured). In this case, all DMRS symbols from an indicated start of a bundle boundary to an indicated end of the bundle boundary may be bundled. That is, the indicated start of the bundle boundary and the indicated end of the bundle boundary may define a bundling window. Accordingly, different bundles may include different quantities of PDSCH occasions or different quantities of slots, according to dynamically indicated bundle boundaries.

As described above, a UE may coherently process DMRS transmissions in a DMRS bundle based on an assumption that phase continuity is maintained across the DMRS bundle. However, in some cases, different PDSCH occasions used for DMRS bundling may be associated with different beams, TCI states, QCL assumptions, and/or the like. In some cases, a UE may receive one or more other channels (e.g., a PDCCH, a CSI-RS, and/or the like) in between PDSCH occasions used for DMRS bundling, and the other channels may be associated with a different beam, TCI state, QCL assumption, and/or the like, than the PDSCH occasions. In such cases, phase continuity may not be maintained across the PDSCH occasions used for DMRS bundling.

Wireless networks generally lack support for techniques to indicate, configure, and/or determine whether phase continuity is maintained across PDSCH occasions that are to be used for DMRS bundling. Some techniques and apparatuses described herein enable determination of whether phase continuity is maintained across such PDSCH occasions. In particular, some techniques and apparatuses described herein enable determination of whether phase continuity is maintained across such PDSCH occasions when a QCL assumption changes in a bundling window. In this way, a UE may identify DMRS transmissions that are to be used for DMRS bundling with greater accuracy, thereby improving channel estimation.

<FIG> is a diagram illustrating an example <NUM> associated with phase continuity for DMRS bundling, in accordance with various aspects of the present disclosure. As shown in <FIG>, a base station <NUM> and a UE <NUM> may communicate with one another. While the example <NUM> is described in terms of QCL assumptions, the example <NUM> may apply equally to other beam indications, such as TCI states.

As shown by reference number <NUM>, the base station <NUM> transmits, and the UE <NUM> receives, an indication for DMRS bundling. For example, the base station <NUM> may transmit an indication that a plurality of PDSCH communications are associated (e.g., time resources, such as DMRS symbols, in PDSCH occasions for the plurality of PDSCH communications are associated) for purposes of DMRS bundling. In some aspects, the indication may be a configuration (e.g., an RRC configuration) for Mode <NUM> DMRS bundling. In this case, the indication may identify a bundling window for DMRS bundling, and the bundling window may include the plurality of PDSCH communications. In some aspects, the indication (e.g., in DCI) may be a configuration for Mode <NUM> DMRS bundling. In this case, the indication may identify a starting boundary for DMRS bundling, and the PDSCH communications may begin at or after the starting boundary. For example, the indication may identify a time resource (e.g., a symbol) in which DMRS bundling is to be initiated or is to be reset. The time period for DMRS bundling beginning at the starting boundary may also be referred to herein as a bundling window.

In some aspects, the indication (e.g., configuration) for DMRS bundling is without regard to whether there is a change in a QCL assumption for communications received by the UE <NUM>. For example, the indication that the plurality of PDSCH communications are associated for purposes of DMRS bundling is without regard to whether there is a change in a QCL assumption (e.g., there are no restrictions on a configuration for DMRS bundling). In other words, the bundling window identified by the indication for DMRS bundling is not based on a recent change in a QCL assumption or whether a QCL assumption is to change during the bundling window. In this case, the UE <NUM> may determine whether phase continuity is maintained across the bundling window after a change in a QCL assumption (e.g., whether to reset DMRS bundling after the change in the QCL assumption) in accordance with one or more rules, as described below.

In some aspects, the indication (e.g., configuration) for DMRS bundling is with regard to whether there is a change in a QCL assumption for communications received by the UE <NUM>. For example, the indication that the plurality of PDSCH communications are associated for purposes of DMRS bundling is with regard to whether there is a change in a QCL assumption (e.g., there are restrictions on a configuration for DMRS bundling). In other words, the bundling window identified by the indication for DMRS bundling is aligned with a recent change in a QCL assumption. For example, the indication for DMRS bundling (e.g., indicating a start of a new bundling window) may coincide with a change in a QCL assumption (e.g., according to a change to a TCI state). That is, the indication for DMRS bundling may indicate a reset in DMRS bundling based at least in part on a change in a QCL assumption. Accordingly, the UE <NUM> may not expect a change in a QCL assumption to occur within a bundling window, but may expect a change in a QCL assumption to occur at the beginning of a bundling window. In this case, the UE <NUM> may determine that phase continuity is maintained across a bundling window that is reset after a change in a QCL assumption.

In some aspects, the base station <NUM> may transmit one or more other indications in addition to the indication for DMRS bundling (e.g., before the indication for DMRS bundling or after the indication for DMRS bundling). For example, the base station <NUM> may transmit, and the UE <NUM> may receive, an indication of whether a QCL type associated with a spatial receive parameter (e.g., QCL Type D) is enabled for PDSCH reception. For example, the base station <NUM> may transmit a PDSCH configuration that indicates whether QCL Type D is configured for PDSCH reception.

As shown by reference number <NUM>, the base station <NUM> transmits, and the UE <NUM> receives, the plurality of PDSCH communications. For example, the base station <NUM> may transmit the plurality of PDSCH communications over a bundling window. As described above in connection with <FIG>, a PDSCH communication may include a DMRS transmission in one or more symbols, and the plurality of PDSCH communications, over the bundling window, may include DMRS transmissions that are to be bundled. A PDSCH communication may also include data in one or more symbols (one or more of which may be shared with DMRSs).

In some aspects, the plurality of PDSCH communications may be dynamically scheduled by the base station in resources (e.g., PDSCH occasions) of the bundling window. For example, the base station may transmit separate DCIs that schedule each of the plurality of PDSCH communications. In this case, a DCI may indicate a TCI state for a PDSCH communication, or the PDSCH communication may use a default QCL assumption. In some aspects, the default QCL assumption for a PDSCH communication may be based at least in part on a QCL assumption for a preceding (e.g., immediately preceding) PDSCH communication (e.g., rather than the default QCL assumption being adopted by the base station and based on a CORESET). However, the default QCL assumption for a first PDSCH communication in a bundling window may be based at least in part on a CORESET (e.g., as indicated above in Tables <NUM> and <NUM>).

In some aspects, the plurality of PDSCH communications may be PDSCH repetitions. In this case, the base station may transmit a single DCI that schedules the repetitions of the same PDSCH payload. The single DCI may indicate a TCI state for all of the repetitions, or the repetitions may use a default QCL assumption. In some aspects, the plurality of PDSCH communications may be scheduled by semi-persistent scheduling (SPS). In this case, the base station may transmit DCI that activates the SPS. The DCI may indicate a QCL assumption (e.g., QCL properties) for the PDSCH occasions of the SPS, or the PDSCH occasions of the SPS may use a default QCL assumption. In some aspects, the bundling window may correspond to a duration of the repetitions or a duration of the SPS (e.g., the bundling window may be implicit, and may not be identified in the indication for DMRS bundling, as described above).

As shown by reference number <NUM>, the UE <NUM> determines whether phase continuity is maintained for the plurality of PDSCH communications in the bundling window. For example, the UE <NUM> may determine whether phase continuity is maintained based at least in part on respective QCL assumptions (e.g., respective QCL properties) for the plurality of PDSCH communications. In some aspects, the UE <NUM> may determine whether phase continuity is maintained based at least in part on respective beam indications, respective TCI states, respective beams, and/or the like, for the plurality of PDSCH communications, in a manner similar to that described below.

In some aspects, the respective QCL assumptions for the plurality of PDSCH communications in the bundling window are the same QCL assumption. For example, the bundling of PDSCH communications may be per TCI state. In some aspects, phase continuity is maintained for multiple PDSCH communications, of the plurality of PDSCH communications, if the QCL assumptions for the multiple PDSCH communications are the same QCL assumption (e.g., if respective TCI states for the multiple PDSCH communications are the same TCI state).

In some aspects, the UE <NUM> may be capable of using only a single TCI state for communications, and phase continuity is maintained for multiple PDSCH communications, of the plurality of PDSCH communications, if a TCI state used by the UE <NUM> is not changed during a duration of the multiple PDSCH communications (e.g., provided the UE <NUM> does not receive a synchronization signal block (SSB) or another initial access communication during a duration of the multiple PDSCH communications). In some aspects, the phase continuity is maintained, provided the TCI state is not changed, even if the UE <NUM> receives another communication, such as a PDCCH communication, a CSI-RS communication, and/or the like, during a duration of the multiple PDSCH communications (e.g., because the UE <NUM> will receive the other communication using the single TCI state).

Accordingly, as shown by reference number 515a, the UE <NUM> may determine that the phase continuity is maintained for multiple PDSCH communications, of the plurality of PDSCH communications, based at least in part on a determination that the QCL assumptions for the multiple PDSCH communications are the same (e.g., based at least in part on a determination that the TCI states for the multiple PDSCH communications are the same).

In some aspects, phase continuity is not maintained for the plurality of PDSCH communications in the bundling window if at least a first and a second PDSCH communication, of the plurality of PDSCH communications, are associated with different QCL assumptions (e.g., associated with different TCI states). In other words, if a QCL assumption (e.g., associated with QCL Type A, QCL Type B, QCL Type C, and/or QCL Type D) changes at a PDSCH communication in the bundling window phase continuity is lost. Accordingly, as shown by reference number 515b, the UE <NUM> may determine that the phase continuity is not maintained between one or more first PDSCH communications and one or more second PDSCH communications, of the plurality of PDSCH communications in the bundling window, associated with different QCL assumptions.

In some aspects, the base station <NUM> may transmit, and the UE <NUM> may receive, one or more other communications (which may be referred to herein as intervening communications) in the bundling window between first and second PDSCH communications, of the plurality of PDSCH communications, and the one or more other communications may be associated with a different QCL assumption than the first and second PDSCH communications. This may be referred to herein as an intervening QCL change scenario. In some aspects, in an intervening QCL change scenario, whether phase continuity is maintained between the first and second PDSCH communications may be based at least in part on whether phase continuity is maintained at the base station <NUM> when transmitting the first and second PDSCH communications and maintained at the UE <NUM> when receiving the first and second PDSCH communications. For example, phase continuity can be maintained if communication hardware (e.g., antenna panels) used to transmit/receive the first and second PDSCH communications is different from communication hardware used to transmit/receive an intervening communication.

In some aspects, the one or more other communications are one or more of a PDCCH communication, a CSI-RS communication, an additional PDSCH communication, or another non-SSB communication. In some aspects, in an intervening QCL change scenario involving a PDCCH, a CSI-RS, and/or an additional PDSCH, phase continuity is maintained between the first and second PDSCH communications if a QCL type associated with a spatial receive parameter (e.g., QCL Type D) is not configured for the UE <NUM> for PDSCH reception. That is, the phase continuity is maintained even if an intervening PDCCH, CSI-RS, and/or other PDSCH, between the first and second PDSCH communications, has a different QCL assumption (e.g., associated with QCL Type A, QCL Type B, or QCL Type C) than the first and second PDSCH communications. Accordingly, as shown by reference number 515c, in an intervening QCL change scenario involving a PDCCH, a CSI-RS, and/or an additional PDSCH, the UE <NUM> may determine that the phase continuity is maintained between the first and second PDSCH communications based at least in part on a determination that a QCL type associated with a spatial receive parameter (e.g., QCL Type D) is not configured for the UE <NUM> for PDSCH reception.

In some aspects, in an intervening QCL change scenario involving a PDCCH, a CSI-RS, and/or an additional PDSCH, phase continuity is not maintained between the first and second PDSCH communications if a QCL type associated with a spatial receive parameter (e.g., QCL Type D) is configured for the UE <NUM> for PDSCH reception. That is, the phase continuity is not maintained when an intervening PDCCH, CSI-RS, and/or other PDSCH, between the first and second PDSCH communications, has a different QCL assumption than the first and second PDSCH communications. In this case, the different QCL assumption may be associated with QCL Type D, or may be associated with QCL Type A, QCL Type B, or QCL Type C (e.g., provided that QCL properties associated with QCL Type A, QCL Type B, and QCL Type C change when a spatial receive parameter changes). Accordingly, as shown by reference number 515d, in an intervening QCL change scenario involving a PDCCH, a CSI-RS, and/or an additional PDSCH, the UE <NUM> may determine that the phase continuity is not maintained between the first and second PDSCH communications based at least in part on a determination that a QCL type associated with a spatial receive parameter (e.g., QCL Type D) is configured for the UE <NUM> for PDSCH reception.

In some aspects, the one or more other communications are one or more SSB communications. In some aspects, in an intervening QCL change scenario involving an SSB, phase continuity is maintained between the first and second PDSCH communications if a QCL type associated with a spatial receive parameter (e.g., QCL Type D) is not configured for the UE <NUM> for PDSCH reception. That is, the phase continuity is maintained even if an intervening SSB, between the first and second PDSCH communications, has a different QCL assumption (e.g., associated with QCL Type A, QCL Type B, or QCL Type C) than the first and second PDSCH communications. Accordingly, as shown by reference number 515e, in an intervening QCL change scenario involving an SSB, the UE <NUM> may determine that the phase continuity is maintained between the first and second PDSCH communications based at least in part on a determination that a QCL type associated with a spatial receive parameter (e.g., QCL Type D) is not configured for the UE <NUM> for PDSCH reception.

In some aspects, in an intervening QCL change scenario involving an SSB, phase continuity is maintained between the first and second PDSCH communications if a QCL type associated with a spatial receive parameter (e.g., QCL Type D) is configured for the UE <NUM> for PDSCH reception, and if the SSB is the QCL source (e.g., the direct QCL source, such as when a TCI state indicates SSB as the QCL source) for the first and/or second PDSCH communications. That is, the phase continuity is maintained even if an intervening SSB, between the first and second PDSCH communications, has a different QCL assumption than the first and second PDSCH communications. Accordingly, as also shown by reference number 515e, in an intervening QCL change scenario involving an SSB, the UE <NUM> may determine that the phase continuity is maintained between the first and second PDSCH communications based at least in part on a determination that a QCL type associated with a spatial receive parameter (e.g., QCL Type D) is configured for the UE <NUM> for PDSCH reception, and that the SSB is the QCL source for the first and/or second PDSCH communications.

In some aspects, in an intervening QCL change scenario involving an SSB, phase continuity is not maintained between the first and second PDSCH communications if a QCL type associated with a spatial receive parameter (e.g., QCL Type D) is configured for the UE <NUM> for PDSCH reception, and if the SSB is not the QCL source (e.g., the direct QCL source) for the first and second PDSCH communications. That is, the phase continuity is not maintained when an intervening SSB, between the first and second PDSCH communications, has a different QCL assumption than the first and second PDSCH communications. Accordingly, as shown by reference number 515f, in an intervening QCL change scenario involving an SSB, the UE <NUM> may determine that the phase continuity is not maintained between the first and second PDSCH communications based at least in part on a determination that a QCL type associated with a spatial receive parameter (e.g., QCL Type D) is configured for the UE <NUM> for PDSCH reception, and that the SSB is not the QCL source for the first and second PDSCH communications.

As described above, the plurality of PDSCH communications may be periodic communications, such as repetitions, SPS communications, and/or the like. In some aspects, phase continuity is maintained for the plurality of PDSCH communications (e.g., periodic communications) if the UE <NUM> does not receive, from the base station <NUM>, another communication (e.g., another channel, such as an SSB, PDCCH, CSI-RS, and/or the like) during a duration of the plurality of PDSCH communications. Accordingly, the UE <NUM> may determine that phase continuity is maintained between one or more first PDSCH communications and one or more second PDSCH communications, of the plurality of PDSCH communications (e.g., periodic communications), based at least in part on a determination that another communication is not received between the one or more first PDSCH communications and the one or more second PDSCH communications.

In some aspects, phase continuity is maintained for the plurality of PDSCH communication (e.g., periodic communications) if the UE <NUM> receives, from the base station <NUM>, another communication (e.g., another channel, such as an SSB, PDCCH, CSI-RS, and/or the like) during a duration of the plurality of PDSCH communications, and the other communication has the same QCL assumption as the plurality of PDSCH communications. Accordingly, the UE <NUM> may determine that phase continuity is maintained between one or more first PDSCH communications and one or more second PDSCH communications, of the plurality of PDSCH communications (e.g., periodic communications), based at least in part on a determination that another communication, associated with a same QCL assumption as the plurality of PDSCH communications, is received between the one or more first PDSCH communications and the one or more second PDSCH communications. If the other communication has a different QCL assumption than the plurality of PDSCH communications, then the UE <NUM> may determine whether phase continuity is maintained as described above (e.g., in an intervening QCL change scenario).

In some aspects, the UE <NUM> may determine whether phase continuity is maintained based at least in part on signaling between the base station <NUM> and the UE <NUM>. In some aspects, the base station <NUM> may transmit (e.g., in an RRC message, a medium access control control element (MAC-CE) message, a PDCCH message, and/or the like), and the UE <NUM> may receive, an indication of whether phase continuity is to be maintained following a change in a QCL assumption during a duration of the plurality of PDSCH communications (e.g., in an intervening QCL change scenario). In some aspects, the UE <NUM> may transmit (e.g., in a UE capability message, a UE assistance information message, and/or the like), and the base station <NUM> may receive, an indication of whether phase continuity is to be maintained following a change in a QCL assumption during a duration of the plurality of PDSCH communications. For example, the base station <NUM> and the UE <NUM> may communicate information that indicates the situations in which a change in a QCL assumption is to result in a loss of downlink phase continuity at the base station <NUM> and/or at the UE <NUM>.

In some aspects, the base station <NUM> and/or the UE <NUM> may transmit an indication of whether phase continuity is to be maintained in an intervening QCL change scenario, involving a PDCCH, a CSI-RS, or an additional PDSCH, for a change in a QCL assumption associated with QCL Type A, QCL Type B, and/or QCL Type C. In some aspects, the base station <NUM> and/or the UE <NUM> may transmit an indication of whether phase continuity is to be maintained in an intervening QCL change scenario, involving a PDCCH, a CSI-RS, or an additional PDSCH, for a change in a QCL assumption associated with QCL Type D.

In some aspects, the base station <NUM> may determine whether phase continuity is maintained for the plurality of PDSCH communications in the bundling window in a manner similar to that described above for the UE <NUM>. In some aspects, the base station <NUM> may transmit the plurality of PDSCH communications based at least in part on determining whether the phase continuity is maintained.

As shown by reference number <NUM>, the UE <NUM> processes the plurality of PDSCH communications based at least in part on determining whether phase continuity is maintained for the plurality of PDSCH communications. In some aspects, the UE <NUM> determines to bundle DMRSs from multiple PDSCH communications for which phase continuity was determined to be maintained. In this case, the UE <NUM> coherently processes the DMRSs from the multiple PDSCH communications for which phase continuity was determined to be maintained. In some aspects, the UE <NUM> determines not to bundle DMRSs from multiple PDSCH communications for which phase continuity was determined not to be maintained. In this case, the UE <NUM> does not coherently process (e.g., the UE <NUM> may individually process) the DMRSs from multiple PDSCH communications for which phase continuity was determined not to be maintained. In this way, a UE may identify DMRS transmissions that are to be used for DMRS bundling with greater accuracy, thereby improving channel estimation.

<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 phase continuity for DMRS bundling.

As shown in <FIG>, proces <NUM> includes receiving, from a base station, an indication that a plurality of PDSCH communications are associated for purposes of DMRS bundling (block <NUM>). For example, the UE (e.g., using antenna <NUM>, demodulator <NUM>, MIMO detector <NUM>, receive processor <NUM>, controller/processor <NUM>, and/or memory <NUM>) may receive, from a base station, an indication that a plurality of PDSCH communications are associated for purposes of DMRS bundling, as described above.

As further shown in <FIG>, process <NUM> includes determining whether a phase continuity is to be maintained for the plurality of PDSCH communications based at least in part on respective QCL assumptions for the plurality of PDSCH communications (block <NUM>). For example, the UE (e.g., using controller/processor <NUM>, memory <NUM>, and/or the like) may determine whether a phase continuity is to be maintained for the plurality of PDSCH communications based at least in part on respective QCL assumptions for the plurality of PDSCH communications, as described above.

As further shown in <FIG>, process <NUM> includes processing the plurality of PDSCH communications based at least in part on whether the phase continuity is to be maintained (block <NUM>). For example, the UE (e.g., using controller/processor <NUM>, memory <NUM>, and/or the like) may process the plurality of PDSCH communications based at least in part on whether the phase continuity is to be maintained, as described above.

In a first aspect, the phase continuity is determined to be maintained for the plurality of PDSCH communications based at least in part on a determination that the respective QCL assumptions are the same.

In a second aspect, alone or in combination with the first aspect, the phase continuity is determined not to be maintained between one or more first PDSCH communications and one or more second PDSCH communications, of the plurality of PDSCH communications, associated with different QCL assumptions.

In a third aspect, alone or in combination with one or more of the first and second aspects, the phase continuity is determined to be maintained for the plurality of PDSCH communications based at least in part on a determination that respective TCI states, for the plurality of PDSCH communications, are the same.

In a fourth aspect, alone or in combination with one or more of the first through third aspects, the UE is capable of using a single TCI state for communication, and the phase continuity is determined to be maintained for the plurality of PDSCH communications based at least in part on a determination that the single TCI state is not changed during a duration of the plurality of PDSCH communications.

In a fifth aspect, alone or in combination with one or more of the first through fourth aspects, process <NUM> includes receiving (e.g., using antenna <NUM>, DEMOD <NUM>, MIMO detector <NUM>, receive processor <NUM>, controller/processor <NUM>, and/or the like) a communication between one or more first PDSCH communications and one or more second PDSCH communications of the plurality of PDSCH communications, and the communication is associated with a QCL assumption that is different from the respective QCL assumptions for the plurality of PDSCH communications.

In a sixth aspect, alone or in combination with one or more of the first through fifth aspects, the communication is a PDCCH, a CSI-RS communication, or an additional PDSCH communication.

In a seventh aspect, alone or in combination with one or more of the first through sixth aspects, the phase continuity is determined to be maintained between the one or more first PDSCH communications and the one or more second PDSCH communications based at least in part on a determination that a QCL type associated with a spatial receive parameter is not configured for PDSCH reception.

In an eighth aspect, alone or in combination with one or more of the first through seventh aspects, the phase continuity is determined not to be maintained between the one or more first PDSCH communications and the one or more second PDSCH communications based at least in part on a determination that a QCL type associated with a spatial receive parameter is configured for PDSCH reception.

In a ninth aspect, alone or in combination with one or more of the first through eighth aspects, the communication is an SSB communication.

In a tenth aspect, alone or in combination with one or more of the first through ninth aspects, the phase continuity is determined to be maintained between the one or more first PDSCH communications and the one or more second PDSCH communications based at least in part on a determination that a QCL type associated with a spatial receive parameter is not configured for PDSCH reception.

In an eleventh aspect, alone or in combination with one or more of the first through tenth aspects, the phase continuity is determined to be maintained between the one or more first PDSCH communications and the one or more second PDSCH communications based at least in part on a determination that a QCL type associated with a spatial receive parameter is configured for PDSCH reception, and that the SSB is a QCL source for the one or more first PDSCH communications and the one or more second PDSCH communications.

In a twelfth aspect, alone or in combination with one or more of the first through eleventh aspects, the phase continuity is determined not to be maintained between the one or more first PDSCH communications and the one or more second PDSCH communications based at least in part on a determination that a QCL type associated with a spatial receive parameter is configured for PDSCH reception, and that the SSB is not a QCL source for the one or more first PDSCH communications and the one or more second PDSCH communications.

In a thirteenth aspect, alone or in combination with one or more of the first through twelfth aspects, the plurality of PDSCH communications are repetitions or are scheduled by SPS.

In a fourteenth aspect, alone or in combination with one or more of the first through thirteenth aspects, the phase continuity is determined to be maintained between one or more first PDSCH communications and one or more second PDSCH communications, of the plurality of PDSCH communications, based at least in part on a determination that another communication is not received between the one or more first PDSCH communications and the one or more second PDSCH communications.

In a fifteenth aspect, alone or in combination with one or more of the first through fourteenth aspects, the phase continuity is determined to be maintained between one or more first PDSCH communications and one or more second PDSCH communications, of the plurality of PDSCH communications, based at least in part on a determination that another communication, associated with a same QCL assumption as the respective QCL assumptions of the plurality of PDSCH communications, is received between the one or more first PDSCH communications and the one or more second PDSCH communications.

In a sixteenth aspect, alone or in combination with one or more of the first through fifteenth aspects, a bundling window for the DMRS bundling corresponds to a duration of the repetitions or a duration of the SPS.

In a seventeenth aspect, alone or in combination with one or more of the first through sixteenth aspects, process <NUM> includes transmitting (e.g., using controller/processor <NUM>, transmit processor <NUM>, TX MIMO processor <NUM>, MOD <NUM>, antenna <NUM>, and/or the like) or receiving (e.g., using antenna <NUM>, DEMOD <NUM>, MIMO detector <NUM>, receive processor <NUM>, controller/processor <NUM>, and/or the like) an indication of whether phase continuity is to be maintained following a change in a QCL assumption during a duration of the plurality of PDSCH communications.

In an eighteenth aspect, alone or in combination with one or more of the first through seventeenth aspects, the indication that the plurality of PDSCH communications are associated for purposes of DMRS bundling is without regard to whether there is a change in a QCL assumption for communications received by the UE.

In a nineteenth aspect, alone or in combination with one or more of the first through eighteenth aspects, determining whether the phase continuity is maintained for the plurality of PDSCH communications is based at least in part on one or more rules.

In a twentieth aspect, alone or in combination with one or more of the first through nineteenth aspects, the indication that the plurality of PDSCH communications are associated for purposes of DMRS bundling is with regard to whether there is a change in a QCL assumption for communications received by the UE.

In a twenty-first aspect, alone or in combination with one or more of the first through twentieth aspects, the indication indicates a reset for associating the plurality of PDSCH communications for purposes of the DMRS bundling when there is a change in a QCL assumption for communications received by the UE.

In a twenty-second aspect, alone or in combination with one or more of the first through twenty-first aspects, a first PDSCH communication, of the plurality of PDSCH communications, is associated with a change in a QCL assumption relative to a previous communication.

In a twenty-third aspect, alone or in combination with one or more of the first through twenty-second aspects, a default QCL assumption for a PDSCH communication, of the plurality of PDSCH communications, is based at least in part on a QCL assumption for a preceding PDSCH communication of the plurality of PDSCH communications.

<FIG> is a diagram illustrating an example process <NUM> performed, for example, by a base station, in accordance with various aspects of the present disclosure. Example process <NUM> is an example where the base station (e.g., base station <NUM>) performs operations associated with phase continuity for DMRS bundling.

As shown in <FIG>, in some aspects, process <NUM> may include transmitting, to a UE, an indication that a plurality of PDSCH communications are associated for purposes of DMRS bundling (block <NUM>). For example, the base station (e.g., using transmit processor <NUM>, TX MIMO processor <NUM>, modulator <NUM>, antenna <NUM>, controller/processor <NUM>, memory <NUM>, and/or scheduler <NUM>) may transmit, to a UE, an indication that a plurality of PDSCH communications are associated for purposes of DMRS bundling, as described above.

As further shown in <FIG>, in some aspects, process <NUM> may include determining whether a phase continuity is to be maintained for the plurality of PDSCH communications based at least in part on respective QCL assumptions for the plurality of PDSCH communications (block <NUM>). For example, the base station (e.g., using controller/processor <NUM>, memory <NUM>, and/or the like) may determine whether a phase continuity is to be maintained for the plurality of PDSCH communications based at least in part on respective QCL assumptions for the plurality of PDSCH communications, as described above.

As further shown in <FIG>, in some aspects, process <NUM> may include transmitting, to the UE, the plurality of PDSCH communications based at least in part on whether the phase continuity is to be maintained (block <NUM>). For example, the base station (e.g., using transmit processor <NUM>, TX MIMO processor <NUM>, modulator <NUM>, antenna <NUM>, controller/processor <NUM>, memory <NUM>, and/or scheduler <NUM>) may transmit, to the UE, the plurality of PDSCH communications based at least in part on whether the phase continuity is to be maintained, as described above.

In a fifth aspect, alone or in combination with one or more of the first through fourth aspects, process <NUM> includes transmitting (e.g., using controller/processor <NUM>, transmit processor <NUM>, TX MIMO processor <NUM>, MOD <NUM>, antenna <NUM>, and/or the like) a communication between one or more first PDSCH communications and one or more second PDSCH communications of the plurality of PDSCH communications, and the communication is associated with a QCL assumption that is different from the respective QCL assumptions for the plurality of PDSCH communications.

In a sixth aspect, alone or in combination with one or more of the first through fifth aspects, the communication is a PDCCH communication, a CSI-RS communication, or an additional PDSCH communication.

In a fourteenth aspect, alone or in combination with one or more of the first through thirteenth aspects, the phase continuity is determined to be maintained between one or more first PDSCH communications and one or more second PDSCH communications, of the plurality of PDSCH communications, based at least in part on a determination that another communication is not transmitted between the one or more first PDSCH communications and the one or more second PDSCH communications.

In a fifteenth aspect, alone or in combination with one or more of the first through fourteenth aspects, the phase continuity is determined to be maintained between one or more first PDSCH communications and one or more second PDSCH communications, of the plurality of PDSCH communications, based at least in part on a determination that another communication, associated with a same QCL assumption as the respective QCL assumptions of the plurality of PDSCH communications, is transmitted between the one or more first PDSCH communications and the one or more second PDSCH communications.

In a sixteenth aspect, alone or in combination with one or more of the first through fifteenth aspects, a bundling window for the DMRS bundling corresponds to a duration of the repetitions or a duration of the semi-persistent scheduling.

In an eighteenth aspect, alone or in combination with one or more of the first through seventeenth aspects, the indication that the plurality of PDSCH communications are associated for purposes of DMRS bundling is without regard to whether there is a change in a QCL assumption for communications transmitted to the UE.

In a twentieth aspect, alone or in combination with one or more of the first through nineteenth aspects, the indication that the plurality of PDSCH communications are associated for purposes of DMRS bundling is with regard to whether there is a change in a QCL assumption for communications transmitted to the UE.

In a twenty-first aspect, alone or in combination with one or more of the first through twentieth aspects, the indication indicates a reset for associating the plurality of PDSCH communications for purposes of the DMRS bundling when there is a change in a QCL assumption for communications transmitted to the UE.

Claim 1:
A method (<NUM>) of wireless communication performed by a user equipment, UE, (<NUM>), comprising:
receiving (<NUM>), from a base station, an indication that a plurality of physical downlink shared channel, PDSCH, communications are associated for purposes of demodulation reference signal, DMRS, bundling; characterized in that it further comprises:
determining (<NUM>) whether a phase continuity is maintained for the plurality of PDSCH communications based at least on respective quasi-co-location, QCL, assumptions for the plurality of PDSCH communications; and
processing (<NUM>) the plurality of PDSCH communications based at least on whether the phase continuity is maintained, wherein the processing (<NUM>) comprises:
coherently processing DMRSs from the plurality of PDSCH communication for which phase continuity is determined to be maintained, and
non-coherently processing DMRSs from the plurality of PDSCH communication for which phase continuity is determined not to be maintained.