Patent Description:
The present disclosure generally relates to communication systems, and more particularly, to feedback in the context of as part of an exchange of information related to a change of a beam for communication.

Qualcomm's document <NPL>" discloses that it is important to have a reliable beam-change command and acknowledgement. Introducing enhanced coverage of signaling can improve the beam reliability that is required for unicast performance and coverage. One example is the reliability of beam switching in FR2, through MAC CE which is carried in DL PDSCH. Enhancing UL signaling can improve the reliability of the beam switching.

In various aspects, of the present disclosure, a base station may communicate with a user equipment (UE) using beamformed communication, such as in millimeter-wave (mmW) or near-mmW system. The base station may control the beams on which the base station and the UE communicate, such as by informing the UE of the beam of the base station that is on which the base station will use for communication with the UE. Responsive to being configured with information indicating the base station beam to use, the UE may select or activate or move to a complementary beam identified during beam training as forming a pair with the base station beam.

Communication on wireless channels, however, carries with it some level of inherent risk, as the random nature of wireless channels may lead to failure of some signals from a transmitter to a receiver. Where those signals carry information configuring a beam pair that the base station will use, failure of the UE to receive those signals may result in radio link failure or loss of timing synchronization, as the UE may be unaware of the configuration change and so may continue using a stale beam. Thus, a need exists to improve the reliability of acknowledging a beam change indication.

The present disclosure provides various techniques and solutions for improving the reliability of acknowledging a beam change indication, e.g., by transmitting the beam change indication on a downlink data channel, such as a physical downlink shared channel (PDSCH). For example, the base station may include the beam change indication in a medium access control (MAC) control element (CE) carried on the PDSCH. This beam change indication on the downlink data channel may be a repetition of another beam change indication carried on a downlink control channel, such as the physical downlink control channel (PDCCH). The UE may receive the beam change indication on the downlink data channel and, in response, may transmit separate acknowledgement (ACK) feedback to the base station. Thus, reliability of acknowledging a beam change indication may be improved, e.g., as the UE may have at least two opportunities to transmit ACK feedback in response to a beam change indication.

Software shall be construed broadly to mean instructions, instruction sets, computer-executable code, code segments, program code, programs, subprograms, software components, applications, software applications, software packages, routines, subroutines, objects, executables, threads of execution, procedures, functions, etc., whether referred to as software, firmware, middleware, microcode, hardware description language, or otherwise.

Accordingly, in one or more example implementations, the functions described may be implemented in hardware, software, or any combination thereof. If implemented in software, the functions may be stored on or encoded as one or more instructions or computer-executable code on a computer-readable medium. By way of example, and not limitation, such computer-readable media can comprise a random-access memory (RAM), a read-only memory (ROM), an electrically erasable programmable ROM (EEPROM), optical disk storage, magnetic disk storage, other magnetic storage devices, combinations of the aforementioned types of computer-readable media, or any other medium that can be used to store computer-executable code in the form of instructions or data structures that can be accessed by a computer.

In an example radio access network (RAN), In various aspects, of the present disclosure, a base station may communicate with a user equipment (UE) using beamformed communication, such as in millimeter-wave (mmW) or near-mmW system. Beamforming may involve some degree of beam training, in which the base station and the UE find the best beams on which to communicate. Even though some beams identified via beam training may not be in active use at a given time, at least one of the UE and/or the base station may maintain a list of candidate beams, e.g., so that the UE and the base station may quickly respond to a blocked beam path or other interference.

The base station may control the beams on which the base station and the UE communicate, such as by informing the UE of the beam of the base station that is on which the base station will use for communication with the UE. Responsive to being configured with information indicating the base station beam to use, the UE may select or activate or move to a complementary beam identified during beam training as forming a pair with the base station beam.

The UE and the base station may then communicate using the complementary beam pair. However, channel conditions are inherently random and time-variant, and therefore, the channel quality of the beam pair on which the base station and the UE communicate may change over time, such as when blockers enter or leave the beam path, when the orientation of the UE is changed, and so forth.

As such changes have the potential to cause channel conditions to drop below acceptable threshold levels, the base station may configure the UE with a new base station beam to be paired with a new UE beam in order to form a complementary beam pair that sees an acceptable channel quality determine a new best beam to use for communication with the UE going forward.

Such a configuration of the UE by the base station may involve the transmission of some information indicative of the beam change. When the UE receives this beam change configuration information, the UE may activate or switch to a UE-side beam that is complementary to the base station-side beam, and the base station and the UE may communicate on that channel, e.g., until such time that the base station reconfigures the active beam pair.

Communication on wireless channels, however, carries with it some level of inherent risk, as the random nature of wireless channels may lead to failure of some signals from a transmitter to a receiver. Where those signals carry information configuring a beam pair that the base station will use, failure of the UE to receive those signals may result in radio link failure or loss of timing synchronization, as the UE may be unaware of the configuration change and so may continue using a stale beam.

As described herein, one solution to improve outcomes in these situations is to have the UE acknowledge reception of beam configuration information. Therefore, the UE may be configured to transmit acknowledgement (ACK) feedback to the base station in response to receiving the information indicating the beam change. The base station-side beam switch may be conditioned upon UE acknowledgement of that switch. However, the same issue arises in this direction: the potential for failure exists with the wireless communication of acknowledgement feedback the base station. Thus, a need exists to improve the reliability of acknowledging a beam change indication.

The present disclosure provides various techniques and solutions for improving the reliability of acknowledging a beam change indication, e.g., by transmitting the beam change indication on a downlink data channel, such as a physical downlink shared channel (PDSCH). For example, the base station may include the beam change indication in a medium access control (MAC) control element (CE) carried on the PDSCH. This beam change indication on the downlink data channel is, according to the invention, a repetition of another beam change indication carried on a downlink control channel, such as the physical downlink control channel (PDCCH). The UE may receive the beam change indication on the downlink data channel and, in response, may transmit separate ACK feedback to the base station. Thus, reliability of acknowledging a beam change indication may be improved, e.g., as the UE may have at least two opportunities to transmit ACK feedback in response to a beam change indication.

The wireless communications system (also referred to as a wireless wide area network (WWAN)) includes base stations <NUM>, UE <NUM>, an Evolved Packet Core (EPC) <NUM>, and another core network <NUM> (e.g., a <NUM> Core (5GC)).

The base stations <NUM> configured for <NUM> Long Term Evolution (LTE) (collectively referred to as Evolved Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access Network (E-UTRAN)) may interface with the EPC <NUM> through first backhaul links <NUM> (e.g., S1 interface). The base stations <NUM> configured for <NUM> NR, which may be collectively referred to as Next Generation RAN (NG-RAN), may interface with core network <NUM> through second backhaul links <NUM>. In addition to other functions, the base stations <NUM> may perform one or more of the following functions: transfer of user data, radio channel ciphering and deciphering, integrity protection, header compression, mobility control functions (e.g., handover, dual connectivity), inter-cell interference coordination, connection setup and release, load balancing, distribution for non-access stratum (NAS) messages, NAS node selection, synchronization, RAN sharing, Multimedia Broadcast Multicast Service (MBMS), subscriber and equipment trace, RAN information management (RIM), paging, positioning, and delivery of warning messages.

In some aspects, the base stations <NUM> may communicate directly or indirectly (e.g., through the EPC <NUM> or core network <NUM>) with each other over third backhaul links <NUM> (e.g., X2 interface). At least some of the base stations <NUM> may be configured for integrated access and backhaul (IAB). Accordingly, such base stations may wirelessly communicate with other such base stations. For example, at least some of the base stations <NUM> configured for IAB may have a split architecture that includes at least one of a central unit (CU), a distributed unit (DU), a radio unit (RU), a remote radio head (RRH), and/or a remote unit, some or all of which may be collocated or distributed and/or may communicate with one another. In some configurations of such a split architecture, the CU may implement some or all functionality of a radio resource control (RRC) layer, whereas the DU may implement some or all of the functionality of a radio link control (RLC) layer.

Illustratively, some of the base stations <NUM> configured for IAB may communicate through a respective CU with a DU of an IAB donor node or other parent IAB node (e.g., a base station), further, may communicate through a respective DU with child IAB nodes (e.g., other base stations) and/or one or more of the UEs <NUM>. One or more of the base stations <NUM> configured for IAB may be an IAB donor connected through a CU with at least one of the EPC <NUM> and/or the core network <NUM>. In so doing, the base station(s) <NUM> operating as an IAB donor(s) may provide a link to the one of the EPC <NUM> and/or the core network <NUM> for other IAB nodes, which may be directly or indirectly (e.g., separated from an IAB donor by more than one hop) and/or one or more of the UEs <NUM>, both of which may have communicate with a DU(s) of the IAB donor(s). In some additional aspects, one or more of the base stations <NUM> may be configured with connectivity in an open RAN (ORAN) and/or a virtualized RAN (VRAN), which may be enabled through at least one respective CU, DU, RU, RRH, and/or remote unit.

The communication links <NUM> between the base stations <NUM> and the UEs <NUM> may include uplink (also referred to as reverse link) transmissions from a UE <NUM> to a base station <NUM> and/or downlink (also referred to as forward link) transmissions from a base station <NUM> to a UE <NUM>. The base stations <NUM> / UEs <NUM> may use spectrum up to Y megahertz (MHz) (e.g., <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, etc. MHz) bandwidth per carrier allocated in a carrier aggregation of up to a total of Yx MHz (x component carriers) used for transmission in each direction. Allocation of carriers may be asymmetric with respect to downlink and uplink (e.g., more or fewer carriers may be allocated for downlink than for uplink).

The D2D communication link <NUM> may use the downlink/uplink WWAN spectrum.

The wireless communications system may further include a Wi-Fi access point (AP) <NUM> in communication with Wi-Fi stations (STAs) <NUM> via communication links <NUM>, e.g., in a <NUM> gigahertz (GHz) unlicensed frequency spectrum or the like.

A similar nomenclature issue sometimes occurs with regard to FR2, which is often referred to (interchangeably) as a "millimeter wave" (or "mmWave" or simply "mmW") band in documents and articles, despite being different from the extremely high frequency (EHF) band (<NUM> - <NUM>) which is identified by the International Telecommunications Union (ITU) as a "millimeter wave" band.

The EPC <NUM> may include a Mobility Management Entity (MME) <NUM>, other MMEs <NUM>, a Serving Gateway <NUM>, an MBMS Gateway <NUM>, a Broadcast Multicast Service Center (BM-SC) <NUM>, and a Packet Data Network (PDN) Gateway <NUM>. The IP Services <NUM> may include the Internet, an intranet, an IP Multimedia Subsystem (IMS), a Packet Switch (PS) Streaming Service, and/or other IP services.

Generally, the AMF <NUM> provides Quality of Service (QoS) flow and session management. All user IP packets are transferred through the UPF <NUM>. The IP Services <NUM> may include the Internet, an intranet, an IMS, a PS Streaming Service, and/or other IP services.

Referring again to <FIG>, in certain aspects, the UE <NUM> may be configured to receive, from the base station <NUM>/<NUM>, a downlink transmission on a downlink data channel including data and an indication of a beam switch. The UE <NUM> may transmit first ACK feedback <NUM> to the base station <NUM>/<NUM> in response to receiving the data. Further, the UE <NUM> may transmit second ACK feedback <NUM> to the base station <NUM>/<NUM> in response to receiving the indication of the beam switch, and the second ACK feedback <NUM> may be separate from the first ACK feedback <NUM>.

Various other aspects and concepts are described herein in the context improving the reliability of beam switching between a UE and a base station.

Although the present disclosure may focus on <NUM> NR, the concepts and various aspects described herein may be applicable to other similar areas, such as LTE, LTE-Advanced (LTE-A), Code Division Multiple Access (CDMA), Global System for Mobile communications (GSM), or other wireless/radio access technologies.

Correspondingly, the base station <NUM>/<NUM> may be configured to transmit, to the UE <NUM>, a downlink transmission on a downlink data channel including data and an indication of a beam switch. The base station <NUM>/<NUM> may then receive the first ACK feedback <NUM> from the UE <NUM> in response to transmitting the data. The base station <NUM>/<NUM> may further, receive the second ACK feedback <NUM> from the UE <NUM> in response to transmitting the indication of the beam switch. Again, the second ACK feedback may be separate from the first ACK feedback.

<FIG> is a diagram <NUM> illustrating an example of downlink channels within a <NUM> NR subframe. <FIG> is a diagram <NUM> illustrating an example of uplink channels within a <NUM> NR subframe. The <NUM> NR frame structure may be frequency division duplexed (FDD) in which for a particular set of subcarriers (carrier system bandwidth), subframes within the set of subcarriers are dedicated for either downlink or uplink, or may be time division duplexed (TDD) in which for a particular set of subcarriers (carrier system bandwidth), subframes within the set of subcarriers are dedicated for both downlink and uplink. In the examples provided by <FIG>, the <NUM> NR frame structure is assumed to be TDD, with subframe <NUM> being configured with slot format <NUM> (with mostly downlink), where D is downlink, U is uplink, and F is flexible for use between downlink/uplink, and subframe <NUM> being configured with slot format <NUM> (with mostly uplink). Slot formats <NUM>, <NUM> are all downlink, uplink, respectively. Other slot formats <NUM>-<NUM> include a mix of downlink, uplink, and flexible symbols. UEs are configured with the slot format (dynamically through DCI, or semi-statically/statically through RRC signaling) through a received slot format indicator (SFI).

A frame, e.g., of <NUM> milliseconds (ms), may be divided into <NUM> equally sized subframes (<NUM>). The symbols on downlink may be cyclic prefix (CP) orthogonal frequency-division multiplexing (OFDM) (CP-OFDM) symbols. The symbols on uplink may be CP-OFDM symbols (for high throughput scenarios) or discrete Fourier transform (DFT) spread OFDM (DFT-s-OFDM) symbols (also referred to as single carrier frequency-division multiple access (SC-FDMA) symbols) (for power limited scenarios; limited to a single stream transmission). For slot configuration <NUM>, different numerologies µ <NUM> to <NUM> allow for <NUM>, <NUM>, <NUM>, <NUM>, and <NUM> slots, respectively, per subframe. The subcarrier spacing may be equal to <NUM>µ * <NUM> kilohertz (kHz), where µ is the numerology <NUM> to <NUM>. <FIG> provide an example of slot configuration <NUM> with <NUM> symbols per slot and numerology µ=<NUM> with <NUM> slots per subframe. The slot duration is <NUM>, the subcarrier spacing is <NUM>, and the symbol duration is approximately <NUM> microseconds (µs). Within a set of frames, there may be one or more different bandwidth parts (BWPs) (see <FIG>) that are frequency division multiplexed. Each BWP may have a particular numerology.

As illustrated in <FIG>, some of the REs carry at least one pilot and/or reference signal (RS) for the UE. In some configurations, an RS may include at least one demodulation RS (DM-RS) (indicated as Rx for one particular configuration, where 100x is the port number, but other DM-RS configurations are possible) and/or at least one channel state information (CSI) RS (CSI-RS) for channel estimation at the UE. In some other configurations, an RS may additionally or alternatively include at least one beam measurement (or management) RS (BRS), at least one beam refinement RS (BRRS), and/or at least one phase tracking RS (PT-RS).

<FIG> illustrates an example of various downlink channels within a subframe of a frame. The PDCCH carries DCI within one or more control channel elements (CCEs), each CCE including nine RE groups (REGs), each REG including four consecutive REs in an OFDM symbol. A PDCCH within one BWP may be referred to as a control resource set (CORESET). Additional BWPs may be located at greater and/or lower frequencies across the channel bandwidth. The physical broadcast channel (PBCH), which carries a master information block (MIB), may be logically grouped with the PSS and SSS to form a synchronization signal (SS)/PBCH block (also referred to as SS block (SSB)). The PDSCH carries user data, broadcast system information not transmitted through the PBCH such as system information blocks (SIBs), and paging messages.

The SRS may be used by a base station for channel quality estimation to enable frequency-dependent scheduling on the uplink.

<FIG> illustrates an example of various uplink channels within a subframe of a frame. The PUCCH carries uplink control information (UCI), such as scheduling requests (SRs), a channel quality indicator (CQI), a precoding matrix indicator (PMI), a rank indicator (RI), and hybrid automatic repeat request (HARQ) ACK / non-acknowledgement (NACK) feedback.

In the downlink, IP packets from the EPC <NUM> may be provided to a controller/processor <NUM>. The controller/processor <NUM> implements Layer <NUM> (L2) and Layer <NUM> (L3) functionality. L3 includes an RRC layer, and L2 includes a service data adaptation protocol (SDAP) layer, a packet data convergence protocol (PDCP) layer, an RLC layer, and a MAC layer.

The transmit (TX) processor <NUM> and the receive (RX) processor <NUM> implement Layer <NUM> (L1) functionality associated with various signal processing functions. L1, which includes a physical (PHY) layer, may include error detection on the transport channels, forward error correction (FEC) coding/decoding of the transport channels, interleaving, rate matching, mapping onto physical channels, modulation/demodulation of physical channels, and MIMO antenna processing. Each transmitter 318TX may modulate a radio frequency (RF) carrier with a respective spatial stream for transmission.

The TX processor <NUM> and the RX processor <NUM> implement L1 functionality associated with various signal processing functions. The data and control signals are then provided to the controller/processor <NUM>, which implements L3 and L2 functionality.

In the uplink, the controller/processor <NUM> provides demultiplexing between transport and logical channels, packet reassembly, deciphering, header decompression, and control signal processing to recover IP packets from the EPC <NUM>.

Similar to the functionality described in connection with the downlink transmission by the base station <NUM>, the controller/processor <NUM> provides RRC layer functionality associated with system information (e.g., MIB, SIBs) acquisition, RRC connections, and measurement reporting; PDCP layer functionality associated with header compression / decompression, and security (ciphering, deciphering, integrity protection, integrity verification); RLC layer functionality associated with the transfer of upper layer PDUs, error correction through ARQ, concatenation, segmentation, and reassembly of RLC SDUs, re-segmentation of RLC data PDUs, and reordering of RLC data PDUs; and MAC layer functionality associated with mapping between logical channels and transport channels, multiplexing of MAC SDUs onto TBs, demultiplexing of MAC SDUs from TBs, scheduling information reporting, error correction through HARQ, priority handling, and logical channel prioritization.

The uplink transmission is processed at the base station <NUM> in a manner similar to that described in connection with the receiver function at the UE <NUM>.

In the uplink, the controller/processor <NUM> provides demultiplexing between transport and logical channels, packet reassembly, deciphering, header decompression, control signal processing to recover IP packets from the UE <NUM>.

In some aspects, at least one of the TX processor <NUM>, the RX processor <NUM>, and the controller/processor <NUM> may be configured to perform aspects in connection with at least one of the data feedback <NUM> and/or the beam switch feedback <NUM> of <FIG>.

In some other aspects, at least one of the TX processor <NUM>, the RX processor <NUM>, and the controller/processor <NUM> may be configured to perform aspects in connection with at least one of the data feedback <NUM> or the beam switch feedback <NUM> of <FIG>.

With reference now to <FIG>, a diagram illustrates example operations in an access network <NUM>. In the access network <NUM>, a base station <NUM> may be configured to communicate with a UE <NUM> using beamforming in a mmW or near-mmW system, such as FR2 of a <NUM> NR RAN. Accordingly, the base station <NUM> may generate or activate a set of beams <NUM>, which may be TX beams used to transmit signaling to the UE <NUM>. For example, the base station <NUM> may apply a spatial transmit filter. Similarly, the UE <NUM> may generate a set of beams <NUM>, which may be RX beams used to receive signaling from the base station <NUM>. For example, the UE <NUM> may apply a spatial receive filter.

In some aspects, the base station <NUM> may configure a set of available beams for the UE <NUM>. For example, the base station <NUM> may transmit a set of transmission configuration indication (TCI) states to the UE <NUM>, and each TCI state may correspond to a TX beam <NUM> that the base station <NUM> may use to transmit downlink signals to the UE <NUM>. The UE <NUM> may pair at least one of the RX beams <NUM> with each of the available beams indicated by the base station <NUM>, e.g., based on reference signals and/or SSBs respectively transmitted using one of the TX beams <NUM> and received using one of the RX beams <NUM>.

The base station <NUM> may select one of the TX beams <NUM> as the "best" beam for communication with the UE <NUM>. For example, the base station <NUM> may determine that a first TX beam 412a is the best beam to be used to transmit to the UE <NUM>, e.g., based on CSI reporting and/or other feedback indicative of channel quality received from the UE <NUM>. The UE <NUM> may use a corresponding first RX beam 414a to receive signaling transmitted by the base station <NUM> using the first TX beam 412a - that is, the UE <NUM> may pair the first RX beam 414a with the first TX beam 412a.

As conditions may change over time, the first TX beam 412a may no longer be the best beam for communication with the UE <NUM> at some point in the future. For example, the base station <NUM> may receive CSI reporting and/or other channel quality feedback that indicates the channel conditions (e.g., RSRP, SINR, etc.) associated with the first TX beam 412a are deteriorating. However, the base station <NUM> may additionally receive CSI reporting and/or other channel quality feedback that indicates the channel conditions associated with a second TX beam 412b are improving. Thus, the base station <NUM> may determine that downlink communication with the UE <NUM> should be switched to the second TX beam 412b, e.g., as the second TX beam 412b has become or is becoming the best beam.

In order to switch between the TX beams <NUM> used by the base station <NUM>, the base station <NUM> should inform the UE <NUM> of the beam change to the second TX beam 412b. Further, the UE <NUM> should acknowledge the beam change to the base station <NUM> so that the base station <NUM> is aware that the UE <NUM> will be able to receive downlink transmissions after the beam switch. Thus, the base station <NUM> may be configured to transmit an indication of the beam change to the UE <NUM> and, correspondingly, the UE <NUM> may be configured to transmit ACK feedback that acknowledges the beam change.

In some aspects, the base station <NUM> may transmit one beam change indication <NUM> to the UE <NUM> on a downlink control channel (e.g., PDCCH), such as in reserved bits of DCI. The UE <NUM> may receive the beam change indication <NUM> or, potentially, may fail to receive the beam change indication <NUM> on the downlink control channel. When the UE <NUM> does receive the beam change indication <NUM> on the downlink control channel, the UE <NUM> may transmit ACK feedback <NUM> to the base station <NUM> in response to the beam change indication <NUM>. For example, the UE <NUM> may transmit the ACK feedback <NUM> on an uplink control channel, such as a PUCCH.

However, the base station <NUM> may fail to receive the ACK feedback <NUM> responsive to the beam change indication <NUM> on the downlink control channel, e.g., due to poor channel conditions, blockers in the beam path, the UE <NUM> being nearly out of coverage, etc. Thus, the base station <NUM> may also be configured to transmit a beam change indication on a downlink data channel, such as a PDSCH. In some aspects, the beam change indication on the downlink data channel may be the same as the beam change indication <NUM> on the downlink control channel - that is, both beam change indications may indicate the same beam to which the base station <NUM> intends to switch.

In some aspects, the UE <NUM> may not always expect to receive a beam change indication on the downlink data channel. Therefore, the UE <NUM> may be configured with a set of parameters and/or the beam change on the downlink data channel may be activated at the UE <NUM>. For example, the UE <NUM> may determine a set of parameters associated with a beam change indication on the downlink data channel and/or associated with acknowledging a beam change indication on the downlink data channel.

In some aspects, the UE <NUM> may determine the set of parameters based on information that is preconfigured at the UE <NUM>. For example, the set of parameters may be stored in memory of the UE <NUM> according to one or more standards and/or specifications set by one or more standards organizations (e.g., 3GPP). In some other aspects, the UE <NUM> may determine the set of parameters based on information received from the base station <NUM>. That is, the base station <NUM> may transmit information indicating the set of parameters to the UE <NUM>, which may configure the UE <NUM> to receive and/or acknowledge a beam change indication on the downlink data channel.

By way of example, the set of parameters may indicate a configuration associated with repeated transmissions of ACK feedback responsive to receiving a beam change indication on the downlink data channel, such as a number of times the UE <NUM> is to transmit ACK feedback responsive to receiving a beam change indication on the downlink data channel. In another example, the set of parameters may indicate a set of resource on an uplink channel (e.g., PUCCH) on which the UE <NUM> is to transmit ACK feedback responsive to a beam change indication carried on the downlink data channel. In a further example, the set of parameters may indicate a format of an uplink control channel (e.g., PUCCH) on which the UE <NUM> is to transmit ACK feedback responsive to a beam change indication carried on the downlink data channel.

In addition, the UE <NUM> may determine that a beam change indication carried on the downlink data channel is active, and based thereon, the UE <NUM> may identify the beam change indication and respond accordingly. In some aspects, the base station <NUM> may transmit information activating the beam change indication on the downlink data channel to the UE <NUM>. Thus, when the UE <NUM> receives such information from the base station <NUM>, the UE <NUM> may be configured to identify the beam change indication and respond accordingly.

In the example access network <NUM>, the beam change indication on the downlink data channel may be activated for the UE <NUM>. Thus, when the base station <NUM> determines that the TX beam used for communication with the UE <NUM> should be switched from the first TX beam 412a to the second TX beam 412b, the base station <NUM> may generate a beam change indication <NUM>, which may indicate the switch to the second TX beam 412b. For example, the beam change indication <NUM> may include information identifying the second TX beam 412b, such as a TCI state corresponding to the second TX beam 412b.

According to various aspects, the base station <NUM> may include the beam change indication <NUM> in a MAC control element (CE). The base station <NUM> may transmit a downlink transmission <NUM> to the UE <NUM> on the downlink data channel using the first TX beam 412a, and the downlink transmission <NUM> may include data and the MAC CE including the beam change indication <NUM>.

The UE <NUM> may receive the downlink transmission <NUM> on the downlink data channel using the first RX beam 414a. Thus, the UE <NUM> may decode the data in the downlink transmission <NUM> and, further, may decode the beam change indication <NUM> included (in the MAC CE) on the downlink data channel. The UE <NUM> may then generate first ACK feedback 424a responsive to the data and may generate second ACK feedback 424b responsive to the beam change indication <NUM>. For example, the UE <NUM> may generate information indicating a respective hybrid automatic repeat request (HARQ) ACK when the UE <NUM> successfully decodes the data and the beam change indication <NUM>, or the UE <NUM> may generate a respective HARQ negative ACK (NACK) when the UE <NUM> fails to successfully decode the data and the beam change indication <NUM>. Thus, in some aspects, each of the first and second ACK feedback 424a-b may indicate either an ACK or a NACK, depending upon whether the data and the beam change indication <NUM>, respectively, is successfully decoded.

The UE <NUM> may subsequently transmit the first ACK feedback 424a to the base station <NUM> in response to receiving the data in the downlink transmission <NUM> on the downlink data channel. Further, the UE <NUM> may transmit the second ACK feedback 424b to the base station <NUM> in response to receiving the beam change indication <NUM> in the downlink transmission <NUM> on the downlink data channel. According to various aspects, the second ACK feedback 424b may be separate from the first ACK feedback 424a.

In one example, the second ACK feedback 424b may be separate from the first ACK feedback 424a in that the second ACK feedback 424b may be transmitted on a second set of resources that is different from a first set of resources on which the first ACK feedback 424a is transmitted. In another example, the second ACK feedback 424b may be separate from the first ACK feedback 424a in that the second ACK feedback 424b may be transmitted in a second format (e.g., PUCCH format) that is different from a first format in which the first ACK feedback 424a is transmitted.

In a further example, the second ACK feedback 424b may be separate from the first ACK feedback 424a in that the second ACK feedback 424b may be transmitted as a second type that is different from a first type as the first ACK feedback 424a is transmitted. Illustratively, the type with which the first and/or second ACK feedback 424a-b may be transmitted may include a set of sequences and/or mapping that may be associated with the uplink control channel (e.g., associated with the PUCCH and/or a format of the PUCCH) on which the first and/or second ACK feedback 424a-b may be transmitted.

In still another example, the second ACK feedback 424b may be separate from the first ACK feedback 424a in that the second ACK feedback 424b may be transmitted using a second transmission method different from a first transmission method used for transmitting the first ACK feedback 424a. Illustratively, the transmission method may refer to transmission of the first ACK feedback 424a and/or second ACK feedback 424b with or without repetition. In some aspects, the transmission method may refer to application of beam diversity (e.g., by using different beams) for transmission of the first ACK feedback 424a and/or second ACK feedback 424b, such as application of beam diversity to different repetitions of the second ACK feedback 424b. In some other aspects, the transmission method may refer to application of frequency diversity for transmission of the first ACK feedback 424a and/or second ACK feedback 424b, such as by using frequency hopping on repetitions of transmissions of the first ACK feedback 424a and/or the second ACK feedback 424b.

Responsive to receiving the beam change indication <NUM> (and/or the beam change indication <NUM> on the downlink control channel), the UE <NUM> may be configured to switch <NUM> to another one of the beams <NUM> that corresponds to the beam indicated by the beam change indication <NUM>. For example, the UE <NUM> may identify the one of the beams <NUM> that corresponds (e.g., is paired with) the one of the base station beams <NUM> indicated by the beam change indication <NUM>, such as by determining an index of one of the beams <NUM> that corresponds to a TCI state of one of the base station beams <NUM> indicated by the beam change indication <NUM>. Illustratively, the UE <NUM> may determine that the second RX beam 414b corresponds to the second TX beam 412b that is identified in the beam change indication <NUM>. The UE <NUM> may then switch to the second RX beam 414b in order to begin receiving downlink transmissions from the base station <NUM> using the second TX beam 412b.

In some aspects, the UE <NUM> may transmit a plurality of repetitions of the second ACK feedback 424b. Potentially, the UE <NUM> may transmit one or more repetitions of the second ACK feedback 424b by applying one of beam diversity (e.g., transmitting different repetitions using different TX beams of the UE <NUM>) and/or frequency diversity (e.g., frequency hopping among repetitions of the second ACK feedback 424b). The UE <NUM> may determine the number of repetitions (as well as other information, such as beam diversity and/or frequency diversity) for transmission of the second ACK feedback 424b based on the determined set of parameters.

In some aspects, the UE <NUM> may delay transmission of at least the second ACK feedback 424b, e.g., by a delay period <NUM>. In so doing, the UE <NUM> may be allotted a sufficient duration to switch <NUM> to the second RX beam 414b. In some aspects, the base station <NUM> may transmit information indicating the delay period <NUM> to the UE <NUM>. In some other aspects, the delay period <NUM> may be preconfigured at the UE <NUM> - e.g., the delay period <NUM> may be stored in memory of the UE <NUM> according to one or more standards and/or specifications set by one or more standards organizations (e.g., 3GPP). The UE <NUM> may initiate a timer for the delay period <NUM> at the end of the downlink transmission <NUM> (e.g., when no more resources are carrying data for the UE <NUM> on the downlink data channel), and the UE <NUM> may then transmit at least the second ACK feedback 424b after the timer reaches the delay period <NUM> or the timer set to the delay period <NUM> elapses.

Correspondingly, the base station <NUM> may receive the first ACK feedback 424a responsive to the data of the downlink transmission <NUM> and the second ACK feedback 424b responsive to the beam change indication <NUM> (included in the MAC CE) of the downlink transmission <NUM> on the downlink data channel. The base station <NUM> may switch <NUM> to the second TX beam 412b in response to receiving the second ACK feedback 424b. As the UE <NUM> may delay transmission of the second ACK feedback 424b for the delay period <NUM>, the base station <NUM> may be configured to refrain from switching to the second TX beam 412b until after the second ACK feedback 424b is received following the delay period <NUM>.

After the base station <NUM> switches <NUM> to the second TX beam 412b and the UE <NUM> switches <NUM> to the second RX beam 414b, the base station <NUM> may use the second TX beam 412b as the "current" beam and/or the "control" beam. For example, the base station <NUM> may transmit another downlink transmission <NUM> to the UE <NUM> using the second TX beam 412b, and the UE <NUM> may receive the other downlink transmission <NUM> using the second RX beam 414b.

<FIG> is a flowchart of a method <NUM> of wireless communication. The method <NUM> may be performed by a UE (e.g., at least one of the UEs <NUM>, <NUM>, <NUM>) and/or another apparatus (e.g., the apparatus <NUM>). According to different aspects, one or more operations of the method <NUM> may be transposed, omitted, and/or contemporaneously performed.

At <NUM>, the UE may determine a set of parameters associated with an indication of a beam change on a downlink data channel. For example, referring to <FIG>, the UE <NUM> may determine a set of parameters associated with the second ACK feedback 424b responsive to the beam change indication <NUM> on the downlink data channel.

In some aspects, the UE may determine the set of parameters based on information that is preconfigured at the UE. For example, the set of parameters may be stored in memory of the UE according to one or more standards and/or specifications set by one or more standards organizations (e.g., 3GPP). The UE may determine the set of parameters by, determining whether the UE is configured to report ACK feedback for beam configuration or beam change information separately from ACK feedback. If the UE is configured for such separate ACK feedback reporting, the UE may access a set of data structures stored in memory of the UE and may load the data structures for use in communicating with a base station.

In some other aspects, the UE may determine the set of parameters based on information received from a base station. That is, the UE may receive, from the base station, information indicating the set of parameters, which may configure the UE to receive and/or acknowledge a beam change indication on the downlink data channel. The UE may receive the information indicating the set of parameters from the base station via RRC signaling or via the indication of the beam change when received on the downlink data channel.

By way of example, the set of parameters may indicate a configuration associated with repeated transmissions of ACK feedback responsive to receiving a beam change indication on the downlink data channel, such as a number of times the UE is to transmit ACK feedback responsive to receiving a beam change indication on the downlink data channel. In another example, the set of parameters may indicate a set of resources on an uplink channel (e.g., PUCCH) on which the UE is to transmit ACK feedback responsive to a beam change indication carried on the downlink data channel. In a further example, the set of parameters may indicate a format of an uplink control channel (e.g., PUCCH) on which the UE is to transmit ACK feedback responsive to a beam change indication carried on the downlink data channel.

At <NUM>, the UE may receive, from the base station, information activating the indication of the beam change on the downlink data channel. Thus, when the UE receives such information from the base station, the UE may be configured to identify the beam change indication on the downlink data channel and respond accordingly. The UE may receive the information activating the beam change indication on the downlink data channel in DCI, which may be specific to the UE or common to a group of UEs. For example, referring to <FIG>, the UE <NUM> may receive, from the base station <NUM>, information activating the beam change indication on the downlink data channel to the UE <NUM>.

At <NUM>, the UE receive, from the base station, a downlink transmission on a downlink data channel including data and the indication of the beam switch. For example, the downlink data channel may be a PDSCH, and the indication of the beam switch may be included in a MAC CE on the PDSCH. In some aspects, the UE may receive the indication of the beam switch in the downlink transmission based on the information activating the beam change indication on the downlink data channel received from the base station. For example, referring to <FIG>, the UE <NUM> may receive, from the base station <NUM>, the downlink transmission <NUM> on the downlink data channel using the first RX beam 414a, and the downlink transmission <NUM> may include data and a MAC CE including the beam change indication <NUM>.

At <NUM>, the UE may transmit first ACK feedback to the base station in response to receiving the data on the downlink data channel. For example, referring to <FIG>, the UE <NUM> may transmit, to the base station <NUM>, the first ACK feedback 424a in response to receiving data of the downlink transmission <NUM> on the downlink data channel.

At <NUM>, the UE may transmit second ACK feedback to the base station in response to receiving the indication of the beam switch. The second ACK feedback may be separate from the first ACK feedback. For example, the second ACK feedback may be included in a different message than the first ACK feedback. According to various aspects, the second ACK feedback may be transmitted on a second set of resources that is different from a first set of resources on which the first ACK feedback is transmitted, the second ACK feedback may be transmitted in a second format (e.g., PUCCH format) that is different from a first format in which the first ACK feedback is transmitted, the second ACK feedback may be transmitted as a second type that is different from a first type as the first ACK feedback is transmitted, and/or the second ACK feedback may be transmitted using a second transmission method different from a first transmission method used for transmitting the first ACK feedback.

According to various other aspects, the UE may transmit the second ACK feedback based on the determined set of parameters. For example, the UE may transmit the second ACK feedback more than once based on a number of repetitions indicated in the second ACK feedback, the UE may transmit the second ACK feedback on a set of resources (e.g., PUCCH resources) indicated by the set of parameters, and/or the UE may transmit the second ACK feedback using a format of an uplink control channel (e.g., PUCCH) indicated by the set of parameters.

According to some further aspects, the UE may transmit the second ACK feedback to the base station after a first time period that follows the downlink transmission on the downlink data channel. The first time period may be received from the base station, or the first time period may be preconfigured at the UE.

For example, referring to <FIG>, the UE <NUM> may transmit the second ACK feedback 424b to the base station <NUM> in response to receiving the beam change indication <NUM> on the downlink data channel.

<FIG> is a flowchart of a method <NUM> of wireless communication. The method <NUM> may be performed by a base station (e.g., at least one of the base stations <NUM>/<NUM>, <NUM>, <NUM>) and/or another apparatus (e.g., the apparatus <NUM>). According to different aspects, one or more operations of the method <NUM> may be transposed, omitted, and/or contemporaneously performed.

At <NUM>, the base station may transmit, to a UE, a set of parameters associated with an indication of a beam change on a downlink data channel. According to different aspects, the base station may transmit the set of parameters to the UE via one of RRC signaling or the indication of the beam change on the downlink data channel. For example, referring to <FIG>, the base station <NUM> may transmit, to the UE <NUM>, a set of parameters associated with the second ACK feedback 424b responsive to the beam change indication <NUM> on the downlink data channel.

By way of example, the set of parameters may indicate a configuration associated with repeated transmissions of ACK feedback responsive to receiving a beam change indication on the downlink data channel, such as a number of times the UE is to transmit ACK feedback responsive to receiving a beam change indication on the downlink data channel. In another example, the set of parameters may indicate a set of resources on an uplink channel (e.g., PUCCH) on which the UE is to transmit ACK feedback responsive to a beam change indication on the downlink data channel. In a further example, the set of parameters may indicate a format of an uplink control channel (e.g., PUCCH) on which the UE is to transmit ACK feedback responsive to a beam change indication on the downlink data channel.

At <NUM>, the base station may transmit, to the UE, information activating the indication of the beam change on the downlink data channel. Thus, when the UE receives such information from the base station, the UE may be configured to identify the beam change indication on the downlink data channel and respond accordingly. The base station may transmit, to the UE, the information activating the beam change indication on the downlink data channel in DCI, which may be specific to the UE or common to a group of UEs. For example, referring to <FIG>, the base station <NUM> may transmit, to the UE <NUM>, information activating the beam change indication on the downlink data channel to the UE <NUM>.

At <NUM>, the base station may transmit, to the UE, a downlink transmission on a downlink data channel including data and the indication of the beam switch. For example, the downlink data channel may be a PDSCH, and the indication of the beam switch may be included in a MAC CE on the PDSCH. In some aspects, the base station may transmit the indication of the beam change in the downlink transmission based on the information activating the beam change indication on the downlink data channel, which may have been earlier transmitted to the UE. For example, referring to <FIG>, the base station <NUM> may transmit, to the UE <NUM>, the downlink transmission <NUM> on the downlink data channel using the first TX beam 412a, and the downlink transmission <NUM> may include data and a MAC CE including the beam change indication <NUM>.

At <NUM>, the base station may receive first ACK feedback from the UE in response to transmitting the data on the downlink data channel. For example, referring to <FIG>, the base station <NUM> may receive, from the UE <NUM>, the first ACK feedback 424a in response to transmitting data of the downlink transmission <NUM> on the downlink data channel.

At <NUM>, the base station may receive second ACK feedback from the UE in response to transmitting the indication of the beam switch. The second ACK feedback may be separate from the first ACK feedback. For example, the second ACK feedback may be included in a different message than the first ACK feedback. According to various aspects, the second ACK feedback may be received on a second set of resources that is different from a first set of resources on which the first ACK feedback is received, the second ACK feedback may be received in a second format (e.g., PUCCH format) that is different from a first format in which the first ACK feedback is received, the second ACK feedback may be received as a second type that is different from a first type as the first ACK feedback is received, and/or the second ACK feedback may be received using a second transmission method different from a first transmission method used for transmitting the first ACK feedback.

According to various other aspects, the base station may receive the second ACK feedback from the UE based on the set of parameters. For example, the base station may receive the second ACK feedback more than once based on a number of repetitions indicated in the second ACK feedback, the base station may receive the second ACK feedback on a set of resources (e.g., PUCCH resources) indicated by the set of parameters, and/or the base station may receive the second ACK feedback according to a format of an uplink control channel (e.g., PUCCH) indicated by the set of parameters.

According to some further aspects, the base station may receive the second ACK feedback from the UE after a first time period that follows the downlink transmission on the downlink data channel. The first time period may be transmitted to the UE by the base station, or the first time period may be preconfigured at the UE.

For example, referring to <FIG>, the base station <NUM> may receive the second ACK feedback 424b from the UE <NUM> in response to transmitting the beam change indication <NUM> on the downlink data channel.

The cellular baseband processor <NUM> communicates through the cellular RF transceiver <NUM> with the UE <NUM> and/or base station <NUM>/<NUM>.

In the context of <FIG>, the cellular baseband processor <NUM> may be a component of the UE <NUM> and may include the memory <NUM> and/or at least one of the TX processor <NUM>, the RX processor <NUM>, and the controller/processor <NUM>. In one configuration, the apparatus <NUM> may be a modem chip and include just the baseband processor <NUM>, and in another configuration, the apparatus <NUM> may be the entire UE (e.g., the UE <NUM> of <FIG>) and include the aforediscussed additional modules of the apparatus <NUM>. In one configuration, the cellular RF transceiver <NUM> may be implemented as at least one of the transmitter 354TX and/or the receiver 354RX.

The apparatus <NUM> may be configured to communicate signaling with a base station <NUM>/<NUM>. To that end, the apparatus <NUM> may include a reception component <NUM> via which the apparatus <NUM> may receive signals, e.g., over the air on a wireless channel with the base station <NUM>/<NUM>. The reception component <NUM> may provide data and/or control information from such received signals to the communication manager <NUM>, which may be configured with a set of components that operate as further described infra.

In addition, the set of components with which the communication manager <NUM> is configured may generate some data and/or control information, as further described infra. The communication manager <NUM> may be operable to provide some or all of the data and/or control information to the transmission component <NUM>, e.g., for transmission over the air to the base station <NUM>/<NUM>. Specifically, the communication manager <NUM> may further include a parameterization component <NUM>, an activation component <NUM>, and an acknowledgement component <NUM>.

The parameterization component <NUM> may be configured to determine a set of parameters associated with an indication of a beam change on a downlink data channel, e.g., as described in connection with <NUM> of <FIG>. For example, the parameterization component <NUM> may determine the set of parameters based on information that is preconfigured at the apparatus <NUM>. The parameterization component <NUM> may access a set of parameters stored in memory of the apparatus <NUM> according to one or more standards and/or specifications set by one or more standards organizations (e.g., 3GPP). The parameterization component <NUM> may determine the set of parameters by, determining whether the separate reporting is configured for ACK feedback for beam configuration or beam change information separately from ACK feedback. If configured for such separate ACK feedback reporting, the parameterization component <NUM> may access a set of data structures stored in memory of the apparatus <NUM> and may load the data structures for use in communicating with the base station <NUM>/<NUM>, such as by providing the some or all determined parameters to the acknowledgement component <NUM>.

In some other aspects, the parameterization component <NUM> may determine the set of parameters based on information received from the base station <NUM>/<NUM>. That is, the parameterization component <NUM> may receive, from the base station <NUM>/<NUM> through the reception component <NUM>, information indicating the set of parameters, which may the parameterization component <NUM> may use to configure the apparatus <NUM> to receive and/or acknowledge a beam change indication on a downlink data channel. The parameterization component <NUM> may receive the information indicating the set of parameters from the base station <NUM>/<NUM> via RRC signaling or via the indication of the beam change when received on the downlink data channel.

By way of example, the set of parameters may indicate a configuration associated with repeated transmissions of ACK feedback responsive to receiving a beam change indication on the downlink data channel, such as a number of times the acknowledgement component <NUM> is to transmit ACK feedback responsive to receiving a beam change indication on the downlink data channel. In another example, the set of parameters may indicate a set of resources on an uplink channel (e.g., PUCCH) on which the acknowledgement component <NUM> (e.g., through the transmission component <NUM>) is to transmit ACK feedback responsive to a beam change indication carried on the downlink data channel. In a further example, the set of parameters may indicate a format of an uplink control channel (e.g., PUCCH) on which the acknowledgement component <NUM> (e.g., through the transmission component <NUM>) is to transmit ACK feedback responsive to a beam change indication carried on the downlink data channel.

The activation component <NUM> may be configured to receive, through the reception component <NUM> from the base station <NUM>/<NUM>, information activating the indication of the beam change on the downlink data channel, e.g., as described in connection with <NUM> of <FIG>. Thus, when the acknowledgement component <NUM> receives (e.g., through the reception component <NUM>) such information from the base station <NUM>/<NUM>, the acknowledgement component <NUM> may be configured to identify the beam change indication on the downlink data channel and respond accordingly. The acknowledgement component <NUM> may receive the information activating the beam change indication on the downlink data channel in DCI, which may be specific to the apparatus <NUM> or common to a group of apparatuses.

The acknowledgement component <NUM> may be configured to receive (e.g., through the reception component <NUM>), from the base station <NUM>/<NUM>, a downlink transmission on a downlink data channel including data and the indication of the beam switch, e.g., as described in connection with <NUM> of <FIG>. For example, the downlink data channel may be a PDSCH, and the indication of the beam switch may be included in a MAC CE on the PDSCH. In some aspects, the acknowledgement component <NUM> may receive the indication of the beam switch in the downlink transmission based on the information activating the beam change indication on the downlink data channel received from the base station <NUM>/<NUM>.

The acknowledgement component <NUM> may be further configured to transmit (e.g., using the transmission component <NUM>) first ACK feedback to the base station <NUM>/<NUM> in response to receiving the data on the downlink data channel, e.g., as described in connection with <NUM> of <FIG>.

The acknowledgement component <NUM> may be further configured to transmit (e.g., using the transmission component <NUM>) second ACK feedback to the base station <NUM>/<NUM> in response to receiving the indication of the beam switch, e.g., as described in connection with <NUM> of <FIG>. The second ACK feedback may be separate from the first ACK feedback. For example, the second ACK feedback may be included in a different message than the first ACK feedback. According to various aspects, the second ACK feedback may be transmitted on a second set of resources that is different from a first set of resources on which the first ACK feedback is transmitted, the second ACK feedback may be transmitted in a second format (e.g., PUCCH format) that is different from a first format in which the first ACK feedback is transmitted, the second ACK feedback may be transmitted as a second type that is different from a first type as the first ACK feedback is transmitted, and/or the second ACK feedback may be transmitted using a second transmission method different from a first transmission method used for transmitting the first ACK feedback.

According to various other aspects, the acknowledgement component <NUM> may transmit (e.g., using the transmission component <NUM>) the second ACK feedback based on the determined set of parameters. For example, the acknowledgement component <NUM> may transmit the second ACK feedback more than once based on a number of repetitions indicated in the second ACK feedback, the acknowledgement component <NUM> may transmit the second ACK feedback on a set of resources (e.g., PUCCH resources) indicated by the set of parameters, and/or the acknowledgement component <NUM> may transmit the second ACK feedback using a format of an uplink control channel (e.g., PUCCH) indicated by the set of parameters.

According to some further aspects, the acknowledgement component <NUM> may transmit the second ACK feedback to the base station <NUM>/<NUM> after a first time period that follows the downlink transmission on the downlink data channel. The first time period may be received from the base station <NUM>/<NUM>, or the first time period may be preconfigured at the apparatus <NUM>.

The apparatus <NUM> may include additional components that perform some or all of the blocks, operations, signaling, etc. of the algorithm(s) in the aforementioned flowchart of <FIG>. As such, some or all of the blocks, operations, signaling, etc. in the aforementioned flowchart of <FIG> may be performed by a component and the apparatus <NUM> may include one or more of those components.

In one configuration, the apparatus <NUM>, and in particular the cellular baseband processor <NUM>, includes means for receiving, from a base station, a downlink transmission on a downlink data channel including data and an indication of a beam switch; means for transmitting first ACK feedback to the base station in response to receiving the data; and means for transmitting second ACK feedback to the base station in response to receiving the indication of the beam switch, the second ACK feedback being separate from the first ACK feedback.

In one configuration, the downlink transmission includes a MAC CE that includes the indication of the beam switch.

In one configuration, the means for transmitting second ACK feedback to the base station in response to receiving the indication of the beam switch is configured to: transmit second ACK feedback to the base station in response to receiving the indication of the beam switch after a first time period following the downlink transmission on the downlink data channel.

In one configuration, the first time period is one of received from the base station or preconfigured at the UE.

In one configuration, the second ACK feedback is at least one of transmitted on a second set of resources different from a first set of resources on which the first ACK feedback is transmitted, transmitted in a second format different from a first format in which the first ACK feedback is transmitted, transmitted as a second type different from a first type as the first ACK feedback is transmitted, or transmitted using a second transmission apparatus different from a first transmission apparatus used for transmitting the first ACK feedback.

In one configuration, the second ACK feedback is transmitted based on a set of parameters that includes at least one of a configuration associated with repeated transmissions of the second ACK feedback, a set of resources on an uplink control channel that carries the second ACK feedback, or a format of the uplink control channel that carries the second ACK feedback.

In one configuration, the set of parameters is preconfigured at the apparatus <NUM>.

In one configuration, the apparatus <NUM>, and in particular the cellular baseband processor <NUM>, includes means for receiving, from the base station, information indicating the set of parameters.

In one configuration, the information indicating the set of parameters is received via one of RRC signaling or the indication of the beam change.

In one configuration, the apparatus <NUM>, and in particular the cellular baseband processor <NUM>, includes means for receiving, from the base station, information activating the indication of the beam change on the downlink data channel.

In one configuration, the information activating the indication of the beam change on the downlink data channel is received via DCI that is one of specific to the UE or common to a group of UEs.

The aforementioned means may be one or more of the aforementioned components of the apparatus <NUM> configured to perform the functions recited by the aforementioned means. As described supra, the apparatus <NUM> may include the TX Processor <NUM>, the RX Processor <NUM>, and the controller/processor <NUM>.

The apparatus <NUM> may be a base station that includes a baseband unit <NUM>. The baseband unit <NUM> may communicate through a cellular RF transceiver with the UE <NUM>. The baseband unit <NUM> may include a computer-readable medium / memory. The baseband unit <NUM> is responsible for general processing, including the execution of software stored on the computer-readable medium / memory. The software, when executed by the baseband unit <NUM>, causes the baseband unit <NUM> to perform the various functions described supra. The computer-readable medium / memory may also be used for storing data that is manipulated by the baseband unit <NUM> when executing software. The baseband unit <NUM> further includes a reception component <NUM>, a communication manager <NUM>, and a transmission component <NUM>. The components within the communication manager <NUM> may be stored in the computer-readable medium / memory and/or configured as hardware within the baseband unit <NUM>. The baseband unit <NUM> may be a component of the base station <NUM> and may include the memory <NUM> and/or at least one of the TX processor <NUM>, the RX processor <NUM>, and the controller/processor <NUM>.

The apparatus <NUM> may be configured to communicate signaling with a UE <NUM>. To that end, the apparatus <NUM> may include a reception component <NUM> via which the apparatus <NUM> may receive signals, e.g., over the air on a wireless channel with the UE <NUM>. The reception component <NUM> may provide data and/or control information from such received signals to the communication manager <NUM>, which may be configured with a set of components that operate as further described infra.

In addition, the set of components with which the communication manager <NUM> is configured may generate some data and/or control information, as further described infra. The communication manager <NUM> may be operable to provide some or all of the data and/or control information to the transmission component <NUM>, e.g., for transmission over the air to the UE <NUM>. Specifically, the communication manager <NUM> may further include a configuration component <NUM>, a switching component <NUM>, and a feedback component <NUM>.

The configuration component <NUM> may be configured to transmit (e.g., through the transmission component <NUM>), to the UE <NUM>, a set of parameters associated with an indication of a beam change on a downlink data channel, e.g., as described in connection with <NUM> of <FIG>. According to different aspects, the configuration component <NUM> may transmit the set of parameters to the UE <NUM> via one of RRC signaling or the indication of the beam change on the downlink data channel.

By way of example, the set of parameters may indicate a configuration associated with repeated transmissions of ACK feedback responsive to receiving a beam change indication on the downlink data channel, such as a number of times the UE <NUM> is to transmit ACK feedback responsive to receiving a beam change indication on the downlink data channel. In another example, the set of parameters may indicate a set of resources on an uplink channel (e.g., PUCCH) on which the UE <NUM> is to transmit ACK feedback responsive to a beam change indication on the downlink data channel. In a further example, the set of parameters may indicate a format of an uplink control channel (e.g., PUCCH) on which the UE <NUM> is to transmit ACK feedback responsive to a beam change indication on the downlink data channel.

The configuration component <NUM> may be configured to transmit (e.g., through the transmission component <NUM>), to the UE <NUM>, information activating the indication of the beam change on the downlink data channel, e.g., as described in connection with <NUM> of <FIG>. Thus, when the UE <NUM> receives such information from the apparatus <NUM>, the UE <NUM> may be configured to identify the beam change indication on the downlink data channel and respond accordingly. The configuration component <NUM> may transmit, to the UE <NUM>, the information activating the beam change indication on the downlink data channel in DCI, which may be specific to the UE <NUM> or common to a group of UE <NUM>.

The switching component <NUM> may be configured to transmit (e.g., through the transmission component <NUM>), to the UE <NUM>, a downlink transmission on a downlink data channel including data and the indication of the beam switch, e.g., as described in connection with <NUM> of <FIG>. For example, the downlink data channel may be a PDSCH, and the indication of the beam switch may be included in a MAC CE on the PDSCH. In some aspects, the switching component <NUM> may transmit the indication of the beam change in the downlink transmission based on the information activating the beam change indication on the downlink data channel, which may have been earlier transmitted to the UE <NUM>.

The feedback component <NUM> may be configured to receive (e.g., through the reception component <NUM>), first ACK feedback from the UE <NUM> in response to transmitting the data on the downlink data channel, e.g., as described in connection with <NUM> of <FIG>.

The feedback component <NUM> may be configured to receive (e.g., through the reception component <NUM>), second ACK feedback from the UE <NUM> in response to transmitting the indication of the beam switch, e.g., as described in connection with <NUM> of <FIG>. The second ACK feedback may be separate from the first ACK feedback. For example, the second ACK feedback may be included in a different message than the first ACK feedback. According to various aspects, the second ACK feedback may be received on a second set of resources that is different from a first set of resources on which the first ACK feedback is received, the second ACK feedback may be received in a second format (e.g., PUCCH format) that is different from a first format in which the first ACK feedback is received, the second ACK feedback may be received as a second type that is different from a first type as the first ACK feedback is received, and/or the second ACK feedback may be received using a second transmission method different from a first transmission method used for transmitting the first ACK feedback.

According to various other aspects, the feedback component <NUM> may receive the second ACK feedback from the UE <NUM> based on the set of parameters. For example, the feedback component <NUM> may receive the second ACK feedback more than once based on a number of repetitions indicated in the second ACK feedback, the feedback component <NUM> may receive the second ACK feedback on a set of resources (e.g., PUCCH resources) indicated by the set of parameters, and/or the feedback component <NUM> may receive the second ACK feedback according to a format of an uplink control channel (e.g., PUCCH) indicated by the set of parameters.

According to some further aspects, the feedback component <NUM> may receive the second ACK feedback from the UE <NUM> after a first time period that follows the downlink transmission on the downlink data channel. The first time period may be transmitted to the UE <NUM> by the configuration component <NUM>, or the first time period may be preconfigured at the UE <NUM>.

The apparatus <NUM> may include additional components that perform some or all of the blocks, operations, signaling, etc. of the algorithm(s) in the aforementioned flowchart of <FIG>. As such, some or all of the blocks, operations, signaling, etc. in the aforementioned flowchart(s) of <FIG> may be performed by a component and the apparatus <NUM> may include one or more of those components.

In one configuration, the apparatus <NUM>, and in particular the baseband unit <NUM>, includes means for transmitting, to a UE, a downlink transmission on a downlink data channel including data and an indication of a beam switch; means for receiving first ACK feedback from the UE in response to transmitting the data; and means for receiving second ACK feedback from the UE in response to transmitting the indication of the beam switch, the second ACK feedback being separate from the first ACK feedback.

wherein the downlink transmission includes a MAC CE that includes the indication of the beam switch.

In one configuration, the means for receiving the second ACK feedback from the UE in response to transmitting the indication of the beam switch is configured to: receive second ACK feedback from the UE in response to transmitting the indication of the beam switch after a first time period following the downlink transmission on the downlink data channel.

In one configuration, the first time period is one of transmitted to the UE or preconfigured at the UE.

In one configuration, the second ACK feedback is at least one of: received on a second set of resources different from a first set of resources on which the first ACK feedback is received, received in a second format different from a first format in which the first ACK feedback is received, received as a second type different from a first type as the first ACK feedback is received, or received according to a second transmission apparatus different from a first transmission apparatus used for transmitting the first ACK feedback.

In one configuration, the second ACK feedback is received based on a set of parameters that includes at least one of a configuration associated with repeated transmissions of the second ACK feedback, a set of resources on an uplink control channel that carries the second ACK feedback, or a format of the uplink control channel that carries the second ACK feedback.

In one configuration, the apparatus <NUM>, and in particular the baseband unit <NUM>, includes means for transmitting, to the UE, information indicating the set of parameters.

In one configuration, the information indicating the set of parameters is transmitted via one of RRC signaling or the indication of the beam change.

In one configuration, the apparatus <NUM>, and in particular the baseband unit <NUM>, includes means for transmitting, to the UE, information activating the indication of the beam change on the downlink data channel.

In one configuration, the information activating the indication of the beam change on the downlink data channel is transmitted via DCI that is one of specific to the UE or common to a group of UEs.

Claim 1:
A method (<NUM>) of wireless communication at a user equipment, UE, comprising:
receiving (<NUM>), from a base station, a downlink transmission on a downlink data channel, the downlink transmission including data and an indication of a beam switch, the indication of a beam switch being a repetition of another beam change indication carried on a downlink control channel;
transmitting (<NUM>) first acknowledgement, ACK, feedback to the base station in response to receiving the data; and
transmitting (<NUM>) second ACK feedback to the base station in response to receiving the indication of the beam switch, the second ACK feedback being separate from the first ACK feedback.