Patent Description:
Aspects of the present disclosure generally relate to wireless communication and to techniques and apparatuses for uplink cross-carrier scheduling for time division multiplexing (TDM) carrier aggregation.

As the demand for mobile broadband access continues to increase, further improvements in LTE, NR, and other radio access technologies and the telecommunication standards that employ these technologies remain useful.

Prior art document <CIT> relates to transmission of (de)activation messages for carrier aggregation.

<FIG> is a diagram illustrating an example <NUM> of a base station <NUM> in communication with a UE <NUM> in a wireless network, in accordance with various aspects of the present disclosure.

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>. The transceiver may be used by a processor (e.g., controller/processor <NUM>) and memory <NUM> to perform aspects of any of the methods described herein.

The transceiver may be used by a processor (e.g., controller/processor <NUM>) and memory <NUM> to perform aspects of any of the methods described herein.

Controller/processor <NUM> of base station <NUM>, controller/processor <NUM> of UE <NUM>, and/or any other component(s) of <FIG> may perform one or more techniques associated with uplink cross-carrier scheduling for time division multiplexing (TDM) carrier aggregation (CA), 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 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, base station <NUM> may include means for configuring an uplink transmission pattern related to an uplink transmission resource on multiple component carriers, means for transmitting, to UE <NUM>, information related to activating the uplink transmission pattern in a single scheduling message, 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.

In some aspects, UE <NUM> may include means for receiving, from base station <NUM>, a single scheduling message including information related to activating an uplink transmission pattern related to an uplink transmission resource on multiple component carriers, means for transmitting information on the multiple component carriers in one or more uplink symbols based at least in part on the uplink transmission pattern, 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, "wireless communication structure" may refer to a periodic time-bounded communication unit defined by a wireless communication standard and/or protocol.

In some aspects, the base station may transmit the PSS, the SSS, and/or the PBCH in a synchronization signal block (SSB).

The available time and frequency resources may be partitioned into resource blocks.

An interlace structure may be used for each of the downlink and uplink for FDD in certain telecommunications systems (e.g., NR). For example, Q interlaces with indices of <NUM> through Q - <NUM> may be defined, where Q may be equal to <NUM>, <NUM>, <NUM>, <NUM>, or some other value. Each interlace may include slots that are spaced apart by Q frames. In particular, interlace q may include slots q, q + Q, q + 2Q, and/or the like, where q ∈ {<NUM>,. , Q - <NUM>}.

Received signal quality may be quantified by a signal-to-interference-plus-noise ratio (SINR), a signal-to-noise ratio (SNR), a reference signal received power (RSRP), a log likelihood ratio (LLR), a reference signal received quality (RSRQ), or some other metric.

New Radio (NR) may refer to radios configured to operate according to a new air interface (e.g., other than Orthogonal Frequency Divisional Multiple Access (OFDMA)-based air interfaces) or fixed transport layer (e.g., other than Internet Protocol (IP)). In some aspects, NR may utilize OFDM with a CP (herein referred to as cyclic prefix OFDM or CP-OFDM) and/or SC-FDM on the uplink, may utilize CP-OFDM on the downlink and include support for half-duplex operation using time division duplexing (TDD). In some aspects, NR may, for example, utilize OFDM with a CP (herein referred to as CP-OFDM) and/or discrete Fourier transform spread orthogonal frequency-division multiplexing (DFT-s-OFDM) on the uplink, may utilize CP-OFDM on the downlink and include support for half-duplex operation using TDD.

Each slot may indicate a link direction (e.g., downlink (DL) or uplink (UL)) for data transmission and the link direction for each slot may be dynamically switched.

<FIG> is a diagram showing an example DL-centric slot <NUM> or wireless communication structure. The DL-centric slot <NUM> may include a control portion <NUM>. The control portion <NUM> may exist in the initial or beginning portion of the DL-centric slot <NUM>. The control portion <NUM> may include various scheduling information and/or control information corresponding to various portions of the DL-centric slot <NUM>. In some aspects, the control portion <NUM> may include legacy PDCCH information, shortened PDCCH (sPDCCH) information), a control format indicator (CFI) value (e.g., carried on a physical control format indicator channel (PCFICH)), one or more grants (e.g., downlink grants, uplink grants, and/or the like), and/or the like.

The DL-centric slot <NUM> may also include a DL data portion <NUM>. The DL data portion <NUM> may sometimes be referred to as the payload of the DL-centric slot <NUM>.

The DL-centric slot <NUM> may also include an uplink (UL) short burst portion <NUM>. The UL short burst portion <NUM> may sometimes be referred to as an uplink burst, an uplink burst portion, a common uplink burst, a short burst, an uplink short burst, a common uplink short burst, a common uplink short burst portion, and/or various other suitable terms. In some aspects, the UL short burst portion <NUM> may include one or more reference signals. Additionally, or alternatively, the UL short burst portion <NUM> may include feedback information corresponding to various other portions of the DL-centric slot <NUM>. For example, the UL short burst portion <NUM> may include feedback information corresponding to the control portion <NUM> and/or the DL data portion <NUM>. Non-limiting examples of information that may be included in the UL short burst portion <NUM> include an ACK signal (e.g., a physical uplink control channel (PUCCH) ACK, a physical uplink shared channel (PUSCH) ACK, an immediate ACK), a NACK signal (e.g., a PUCCH NACK, a PUSCH NACK, an immediate NACK), a scheduling request (SR), a buffer status report (BSR), a hybrid automatic repeat request (HARQ) indicator, a channel state indication (CSI), a channel quality indicator (CQI), a sounding reference signal (SRS), a demodulation reference signal (DMRS), PUSCH data, and/or various other suitable types of information. The UL short burst portion <NUM> may include additional or alternative information, such as information pertaining to random access channel (RACH) procedures, scheduling requests, and various other suitable types of information.

The foregoing is one example of a DL-centric wireless communication structure, and alternative structures having similar features may exist without deviating from the aspects described herein.

<FIG> is a diagram showing an example of an uplink (UL)-centric slot <NUM> or wireless communication structure. The UL-centric slot <NUM> may include a control portion <NUM>. The control portion <NUM> may exist in the initial or beginning portion of the UL-centric slot. The control portion <NUM> in <FIG> may be similar to the control portion <NUM> described above with reference to <FIG>. The UL-centric slot <NUM> may also include an uplink (UL) long burst portion <NUM>. The UL long burst portion <NUM> may sometimes be referred to as the payload of the UL-centric slot <NUM>. The term "UL portion" may refer to the communication resources utilized to communicate UL data from the subordinate entity (e.g., UE) to the scheduling entity (e.g., UE or BS). In some configurations, the control portion <NUM> may be a physical downlink control channel (PDCCH).

The UL-centric slot <NUM> may also include an uplink short burst portion <NUM>. The UL short burst portion <NUM> in <FIG> may be similar to the UL short burst portion <NUM> described above with reference to <FIG>, and may include any of the information described above in connection with <FIG>. The foregoing is one example of an uplink-centric wireless communication structure, and alternative structures having similar features may exist without necessarily deviating from the aspects described herein.

<FIG> is a diagram illustrating examples <NUM> of carrier aggregation, in accordance with various aspects of the present disclosure.

Carrier aggregation is a technology that enables two or more component carriers (CCs, sometimes referred to as carriers) to be combined (e.g., into a single channel) for a single UE to enhance data capacity. As shown, component carriers can be combined in the same or different frequency bands, the same or different frequency ranges, and/or the like. Additionally, or alternatively, contiguous or non-contiguous component carriers can be combined. A base station may configure carrier aggregation for a UE, such as in a radio resource control (RRC) message, downlink control information (DCI), and/or the like.

As shown by reference number <NUM>, in some aspects, carrier aggregation may be configured in an intra-band contiguous mode where the aggregated component carriers are contiguous to one another and are in the same frequency band. As shown by reference number <NUM>, in some aspects, carrier aggregation may be configured in an intra-band non-contiguous mode where the aggregated component carriers are in the same frequency band and are non-contiguous to one another. As shown by reference number <NUM>, in some aspects, carrier aggregation may be configured in an inter-band non-contiguous mode where the aggregated component carriers are non-contiguous to one another and are in different frequency bands.

In carrier aggregation, a UE and a base station may communicate via multiple carriers that may have different frequencies, which may be contiguous within a particular frequency band, non-contiguous within a particular frequency band, non-contiguous across different frequency bands within a particular frequency range, non-contiguous across different frequency bands within different frequency ranges, and/or the like. For example, in NR, frequency bands may be separated into different frequency ranges, which may include Frequency Range <NUM> (FR1) that includes frequency bands below <NUM> gigahertz (GHz) (also known as sub-<NUM>) and Frequency Range <NUM> (FR2) that includes millimeter wave (mmW) frequency bands. In general, carrier aggregation features can enable increased bandwidth, increased throughput, increased reliability, and/or the like for communications between the UE and the base station (e.g., enabling cross-carrier communication based at least in part on different spectrum usage techniques). For example, frequency division duplexing (FDD) and time division duplexing (TDD) are two spectrum usage techniques that can be used in a wireless communication system. In particular, in a frequency band that operates in FDD mode, two different component carriers (or carrier frequencies) are paired and simultaneously used for the uplink and the downlink with a guard band separating the two component carriers to ensure that the transmitter and receiver do not interfere with one another. In contrast, in a frequency band that operates in TDD mode, a single component carrier is used for both transmit and receive operations in alternating time slots.

In general, FDD mode and TDD mode may be associated with respective tradeoffs. For example, whereas FDD mode consumes substantial frequency spectrum due to requiring paired uplink and downlink spectrum and a guard band, TDD mode does not use paired spectrum and can therefore be implemented in any available spectrum without requiring any spectrum-wasteful guard bands or channel separations. Furthermore, because the proportion of time slots that are allocated to uplink and downlink traffic can be dynamically varied, TDD mode can more efficiently serve application traffic that may require asymmetric data rates (e.g., more time slots can be allocated to the downlink to support a higher data rate on the downlink). Another advantage of TDD mode is that channel propagation is the same in both the uplink and downlink directions, which enables special antenna techniques such as multiple-input multiple-output (MIMO) and beamforming that otherwise require more complex dynamic tuning circuitry in FDD mode to make antenna bandwidths broad enough to cover both sets of paired spectrum (and the intervening, unused, guard band).

However, because TDD mode operates based at least in part on allocated time slots, a successful TDD implementation depends on a very precise phase and/or timing synchronization to avoid interference between uplink and downlink transmissions, which means that FDD mode can potentially achieve a higher data rate than TDD mode over a similar distance because paired spectrum is used on a continuous basis in both the uplink and downlink directions. Furthermore, another advantage of FDD mode is that radio planning tends to be easier and more efficient because neighboring base stations transmit and receive in different sub-bands, component carriers, and/or the like. On the other hand, in TDD mode, spectral efficiency may be decreased because a guard time is maintained between neighboring base stations, or neighboring base stations may be synchronized to transmit and receive at the same time, which increases network complexity and cost in addition to reducing scheduling flexibility because all neighboring base stations have to use the same uplink to downlink ratio.

Accordingly, due to the respective advantages and tradeoffs associated with FDD mode and TDD mode, some inter-band carrier aggregation scenarios may involve concurrent deployment of TDD mode and FDD mode in different frequency bands, component carriers, and/or the like. For example, because TDD mode uses less spectrum than FDD mode, permits time slots to asymmetrically allocated to the uplink and the downlink based at least in part on application (e.g., quality of service) requirements, simplifies MIMO, beamforming, and other special antenna techniques due to channel reciprocity, and/or the like, NR networks are expected to use frequency bands that operate in TDD mode (e.g., the n78 band) as a primary cell (Pcell). Furthermore, some mobile network operators (MNOs) may deploy NR on frequency bands that operate in FDD mode as a secondary cell (Scell) because FDD mode potentially offers better coverage performance, lower costs, and/or the like due to low penetration compared with frequency bands that operate in TDD mode, reduced HARQ latency because the uplink is always available, and/or the like. However, there may be various challenges with concurrently deploying one or more component carriers in the Pcell and one or more component carriers in the Scell with inter-band carrier aggregation, especially with respect to uplink transmissions.

For example, inter-band carrier aggregation may be associated with a configuration in which one or more FDD component carriers in a first frequency band are combined with one or more TDD component carriers in a second frequency band, a configuration in which one or more TDD component carriers in a first frequency band are combined with one or more TDD component carriers in a second frequency band, and/or the like. In general, inter-band carrier aggregation may be implemented using time division multiplexing (TDM), meaning that a UE can perform only one uplink transmission in any given time interval (e.g., via either a Pcell or an Scell) to avoid thermal issues that may otherwise arise if a UE were to perform simultaneous transmissions via the Pcell and one or more Scells, via different Scells, and/or the like.

Furthermore, another consideration relates to scheduling efficiency for inter-band carrier aggregation implemented using TDM. For example, in some cases, one or more uplink transmission resources may be reserved to a UE, a group of UEs, and/or the like to reduce transmission latency, reduce scheduling overhead, and/or the like. In particular, in LTE networks, semi-persistent scheduling (SPS) generally enables radio resources to be semi-statically configured and allocated to a specific UE for more than one subframe, which may avoid the need for specific downlink assignment messages over a physical downlink control channel (PDCCH) for each subframe. To configure SPS, radio resource control (RRC) signaling may indicate an interval at which the radio resources are periodically assigned. PDCCH signaling may indicate specific transmission resource allocations in a time/frequency domain and further indicate one or more transmission attributes (e.g., periodicity, modulation and control scheme (MCS), time offset, transmit power, and/or the like). For uplink SPS, non-adaptive synchronous hybrid automatic repeat request (HARQ) is performed. For example, non-adaptive retransmissions may be performed on a same resource and with a same MCS as was used for a last (e.g., previous) transmission. Furthermore, to support certain service types (e.g., ultra reliable low latency communication (URLLC), enhanced mobile broadband (eMBB), massive machine-type communications (MMTC), and/or the like) that may have different requirements with respect to reliability, latency, data rates, communication range, and/or the like, NR networks may support two types of reserved uplink transmission resources to enable uplink transmissions without a grant, generally referred to as a configured grant (CG). More particularly, in a Type <NUM> configured grant, a UE can perform uplink data transmission without a grant based at least in part on an RRC (re)configuration without any L1 signaling, and in a Type <NUM> configured grant, the UE can perform uplink data transmission without a grant based at least in part on RRC (re)configuration in combination with L1 signaling to activate and/or release the Type <NUM> configured grant.

In NR networks, carrier aggregation may be supported through self-scheduling in which an Scell uplink is scheduled by the corresponding Scell downlink (e.g., the downlink spectrum paired with the uplink spectrum) and/or through cross-carrier scheduling in which the Pcell schedules both and the Scell uplink and the Scell downlink (e.g., in one or more downlink slots based at least in part on the TDD configuration). However, because the uplink is time division multiplexed (or "TDMed"), scheduling the Scell uplink may interrupt an uplink SPS configuration on the same carrier in one or more slots, which may necessitate dynamic scheduling for the interrupted slot(s). Furthermore, similar issues may arise with respect to an uplink configured grant that is reserved to UEs at a group level, a cell level, and/or the like to enable UEs to perform a fast uplink transmission. However, in addition to potentially interrupting one or more slots in which a UE can perform an uplink transmission based at least in part on the uplink configured grant, further challenges may arise because a configured grant typically supports repetition of the same symbol in subsequent consecutive slots (e.g., to improve reliability). Accordingly, in cases where a UE is assigned one or more reserved uplink resources on a particular carrier (e.g., an uplink SPS configuration, a configured grant, and/or the like), a scheduling message related to TDM carrier aggregation on another carrier may interrupt usage of the one or more reserved uplink resources, cause failure of repetition of the same symbol in subsequent consecutive slots, and/or the like.

Some aspects described herein provide techniques and apparatuses that may combine one or more uplink transmission patterns with uplink cross-carrier SPS and configured grant scheduling for TDM carrier aggregation. For example, as will be described in further detail below, the uplink transmission pattern for an uplink SPS configuration may be provided or otherwise indicated to the UE in an RRC signaling message, and a subsequent downlink control information (DCI) message can be used to activate the uplink SPS configuration. For example, the uplink transmission pattern may include a periodicity of the uplink SPS configuration in a quantity of slots, an expiration timer expressed according to a number of milliseconds, band information and a related transmission pattern, and/or the like. Additionally, or alternatively, for a band-specific configured grant, an RRC configuration may include an information element (IE) (e.g., rrc-ConfiguredUplinkGrant) to indicate a frequency and/or band, define a frequency and time resource for each frequency and/or band, indicate a user time domain offset or define a slot-level offset value, and/or the like. In this way, the UE may be informed about which reserved uplink resources may potentially be interrupted, which allows the UE to perform one or more uplink transmissions (e.g., via the Pcell, the Scell, and/or the like) to avoid the potential interruption. Furthermore, in the case of an uplink configured grant, the UE may perform repetition in consecutive slots in a manner that avoids one or more slots that are indicated to be unavailable in the RRC IE.

Furthermore, in addition to the above-mentioned challenges that relate to scheduling efficiency, enabling TDM carrier aggregation based at least in part on TDD operation in the Pcell, and FDD and/or TDD operation in one or more Scells, poses challenges with respect to compliance with limits, requirements, and/or the like that relate to a Specific Absorption Rate (SAR), which refers to a rate at which the human body absorbs energy when exposed to radio frequency (RF) signals (e.g., power absorbed per mass of tissue, which may be expressed according to watts per kilogram (W/kg)). In particular, SAR requirements generally specify that overall radiated power by a UE is to remain under a certain level for human safety. Accordingly, a UE operating at a high transmit power in the Pcell or TDD band (e.g., based at least in part on a network configuration) may have to reduce an uplink transmission duty cycle on the Scell(s) in order to adhere to or otherwise comply with an SAR requirement, which may prevent the UE from using all available uplink slots to transmit. For example, a percentage of allowed uplink transmissions on the Scell(s) may depend on the uplink transmissions on the Pcell or TDD band, which is generally configured or otherwise scheduled by a base station and the UE only needs to follow the scheduling by the base station. Accordingly, a reserved uplink resource (e.g., an uplink SPS configuration, configured grant, and/or the like) may allow a UE to exceed the SAR requirement in cases where the UE is unaware of a limit on allowed uplink transmissions. Furthermore, without knowing UE-specific allowed uplink transmission information, a base station may pessimistically configure a cell-specific value for allowed uplink transmissions based at least in part on an assumption that the UE will use all available uplink transmission slots with a maximum power to guarantee that the UE will not exceed the SAR requirement.

Accordingly, some aspects described herein provide techniques and apparatuses that may configure a UE-specific duty cycle pattern (e.g., a percentage of slots in which uplink transmissions are allowed on an Scell) to fractionally increase uplink transmission power. For example, to increase uplink transmission power, the UE-specific duty cycle pattern may have a reduced quantity of uplink transmission slots (e.g., dividing a total allowed uplink transmission power among a smaller quantity of slots may result in an increase of uplink transmission power per slot). In some aspects, in cases where TDM inter-band carrier aggregation is implemented with a combination of one or more TDD component carriers in a first frequency band and one or more FDD component carriers in a second frequency band, the Pcell may configure the duty cycle pattern such that the UE operates at a higher power in the TDD band because the higher power can support uplink MIMO to increase overall uplink throughput and because the FDD band may have a smaller bandwidth than the TDD band (e.g., <NUM> versus <NUM>), whereby operating at a relatively lower power may not cause excessive performance degradation. Accordingly, to configure the TDD band with a higher power, the UE-specific duty cycle pattern may be configured such that at least some uplink transmission slots in the FDD band are unused to satisfy the SAR requirement, and the UE may comply with the SAR requirement by following the configuration provided in the UE-specific duty cycle pattern when performing uplink transmissions.

<FIG> is a diagram illustrating an example <NUM> of uplink cross-carrier scheduling for time division multiplexing (TDM) carrier aggregation, in accordance with various aspects of the present disclosure. As shown in <FIG>, a UE <NUM> may be in communication with a base station <NUM> in a wireless network (e.g., wireless network <NUM> and/or the like). Furthermore, as described herein, the UE <NUM> and the base station <NUM> may communicate using an inter-band carrier aggregation configuration. For example, in some aspects, the inter-band carrier aggregation configuration may include one or more component carriers in a first frequency band that is configured in a TDD mode and one or more component carriers in a second frequency band that is configured in an FDD mode. Additionally, or alternatively, the inter-band carrier aggregation configuration may include one or more component carriers in a first frequency band that is configured in a TDD mode and one or more component carriers in a second frequency band that is also configured in an TDD mode.

As shown in <FIG>, and by reference number <NUM>, the base station <NUM> may configure a cross-carrier uplink transmission pattern based at least in part on one or more reserved uplink resources that are assigned to the UE <NUM>, based at least in part on an SAR requirement applicable to the UE <NUM>, and/or the like. For example, as mentioned above, the cross-carrier uplink transmission pattern may generally relate to an uplink transmission pattern to be used in a TDM carrier aggregation scenario, where the base station <NUM> may be configured to communicate with the UE <NUM> via a Pcell including one or more component carriers in a first frequency band operating in TDD mode, via one or more Scells including one or more component carriers in a second frequency band operating in FDD mode and/or TDD mode, and/or the like. In some aspects, the cross-carrier uplink transmission pattern may indicate a set of one or more slots, symbols, subframes, and/or the like associated with a TDM pattern that are available to use for the reserved uplink resource(s) assigned to the UE <NUM> across multiple frequency bands, multiple component carriers within a particular frequency band, and/or the like. For example, in some aspects, the cross-carrier uplink transmission pattern may indicate that the set of one or more slots, symbols, subframes, and/or the like can be used to perform one or more uplink transmissions, one or more repetitions of an uplink transmission, and/or the like (e.g., when one or more messages used to schedule the one or more Scells interrupt usage of the reserved uplink resource(s) assigned to the UE <NUM>).

In some aspects, the base station <NUM> may determine the cross-carrier uplink transmission pattern based at least in part on hard coded information stored in a memory of the base station (e.g., according to a cross-carrier uplink transmission pattern indicated in a 3GPP standard for the reserved uplink resource(s) assigned to the UE <NUM>, the SAR requirement applicable to the UE <NUM>, and/or the like). Additionally, or alternatively, the base station <NUM> may determine the cross-carrier uplink transmission pattern based at least in part on scheduling information derived at the base station <NUM> (e.g., based at least in part on the reserved uplink resource(s) assigned to the UE <NUM>, the SAR requirement applicable to the UE <NUM>, and/or the like). Furthermore, in some aspects, the information that the base station <NUM> uses to derive or otherwise determine the cross-carrier uplink transmission pattern (e.g., the hard coded information, the scheduling information, and/or the like) may be transparent to the UE <NUM>, which may follow the cross-carrier uplink transmission pattern as indicated in one or more scheduling messages that the base station <NUM> transmits to the UE <NUM>, as further described elsewhere herein.

In some aspects, to configure the cross-carrier uplink transmission pattern based at least in part on one or more reserved uplink resources that are assigned to the UE <NUM>, the base station <NUM> may use different approaches depending on whether the reserved uplink resources include an uplink SPS configuration, an uplink configured grant, and/or the like. For example, in cases where the reserved uplink resources include an uplink SPS configuration, the uplink transmission pattern may be configured via RRC signaling, and a subsequent DCI message may be used to activate the uplink SPS configuration. In some aspects, the uplink SPS configuration may include a periodicity of the uplink SPS configuration (e.g., a quantity of slots) and an expiration timer (e.g., a quantity of milliseconds). Furthermore, the uplink SPS configuration may include information related to one or more bands that are associated with the uplink SPS configuration and the transmission patterns to be used on the one or more bands. In this way, by configuring the transmission pattern for one particular band (e.g., the Pcell operating in TDD mode, an Scell operating in FDD mode, an Scell operating in TDD mode, and/or the like), the transmission pattern may be applied across all bands with no interruption to the uplink SPS configuration. For example, for a TDD band, the UE <NUM> may use any available uplink slots based at least in part on the applicable TDD configuration, and the UE <NUM> may similarly use any of the available uplink slots for an FDD band because the uplink is always available. In some aspects, the base station <NUM> may additionally configure the DCI message to activate the uplink SPS configuration. For example, the DCI message may include one or more resources (e.g., symbols, resource blocks (RBs), and/or the like) associated with the transmission pattern and an SPS radio network temporary identifier (SPS-RNTI) that may be included in a content of the DCI message, scrambled with a cyclic redundancy code (CRC), and/or the like. Additionally, or alternatively, the one or more resources associated with the transmission pattern may be included in the RRC signaling under information associated with each band.

Furthermore, in cases where the reserved uplink resources include an uplink configured grant, the uplink transmission pattern may be a band-specific configuration that is configured via RRC signaling. For example, an RRC message may include an information element (IE) related to the uplink configured grant, such as a ConfiguredGrantConfig IE. In some aspects, the IE related to the uplink configured grant may include one or more fields or elements to indicate a list of one or more frequencies and/or bands associated with the uplink configured grant and one or more fields or elements to define one or more frequency resources, one or more time resources, and/or the like for each frequency and/or band. In this way, the base station <NUM> can configure the list of frequencies and/or bands associated with the uplink configured grant and the frequency and/or time resources to define the uplink transmission pattern to be used for each frequency and/or band (e.g., slots that are available for uplink transmission, slots that are unavailable for uplink transmission, and/or the like). Furthermore, in some aspects, the IE related to the uplink configured grant may include a user time domain offset (e.g., related to a single frequency network (SFN)) and/or one or more fields or elements to define a slot-level offset (e.g., to account for cases in which a frame structure may exceed a maximum value of the time domain offset). In this way, the UE <NUM> may know which slots are available and which slots are unavailable for uplink transmission, and may thereby repeat one or more transmissions and/or avoid repeating one or more transmissions in consecutive slots based at least in part on the slot(s) availability indicated by the above information in the RRC IE.

Furthermore, to ensure compliance with the SAR requirement applicable to the UE <NUM>, the base station <NUM> may configure the cross-carrier uplink transmission pattern based at least in part on an overall fraction of transmission slots that the UE <NUM> is allowed to use for an FDD uplink. In this case, the base station <NUM> may be aware of a quantity of TDD slots that the UE <NUM> is using to transmit at a high power and derive a quantity of uplink slots that the UE <NUM> is permitted to use in an FDD band based at least in part on the quantity of TDD slots that the UE <NUM> is using to transmit at a high power. Furthermore, in cases where the UE <NUM> is assigned a reserved uplink transmission resource that allows the UE <NUM> to transmit without having to first provide an uplink scheduling request (e.g., an uplink SPS configuration, an uplink configured grant, and/or the like), the UE <NUM> could potentially exceed the SAR requirement if the UE <NUM> does not know how many slots can be used for FDD uplink transmissions. Accordingly, the base station <NUM> may configure the cross-carrier uplink transmission pattern based at least in part on a maximum quantity of slots that can be used for FDD uplink transmissions, which can then be indicated to the UE <NUM> to ensure short-term and long-term compliance with the SAR requirement. In some aspects, the base station <NUM> may determine the maximum quantity of slots that can be used for FDD uplink transmissions without violating the SAR requirement based at least in part on UE-specific information, which avoids a need to pessimistically configure the maximum quantity of slots based on the (potentially incorrect) assumption that the UE <NUM> will use a maximum transmit power in all available uplink TDD slot(s).

For example, in some aspects, the base station <NUM> may configure a DCI message to indicate an allowed uplink transmission pattern that may be designed to guarantee short-term (e.g., substantially real-time) compliance with the SAR requirement. In some aspects, the DCI message may be dynamically configured to guarantee short-term compliance with the SAR requirement within a few slots, a single slot, a portion of a single slot, and/or the like. For example, in some aspects, the base station <NUM> may configure the DCI message to include one or more elements related to an uplink grant to indicate, to the UE <NUM>, the allowed uplink transmission pattern to be in effect until a next scheduling message (e.g., a UE-specific duty cycle indicating a percentage or quantity of allowed slots for FDD uplink transmission). In some aspects, the allowed uplink transmission pattern may include a quantity of slots and/or symbols available for FDD uplink transmission, which the base station <NUM> may derive based at least in part on an actual transmit power used by the UE <NUM> in one or more scheduled symbols associated with the uplink grant (e.g., an amount of energy the UE <NUM> is already using during the one or more scheduled symbols associated with the uplink grant). Additionally, or alternatively, in some aspects, the allowed uplink transmission pattern may include a maximum allowed transmit power that the UE <NUM> can use before the next scheduling message (e.g., <NUM> dBm). For example, if the UE <NUM> is located relatively close to the base station <NUM>, the UE <NUM> may not need to use a maximum available transmit power. In such cases, the UE <NUM> can use a lower transmit power to increase the quantity of slots or symbols that are available for uplink transmissions. In this way, configuring the DCI message to indicate the maximum allowed transmit power until the next scheduling message may provide the UE <NUM> with more flexibility to self-determine how to allocate available transmit power, increase or decrease the quantity of symbols or slots available for uplink transmissions, and/or the like while adhering to an overall SAR energy limit.

Additionally, or alternatively, in some aspects, the base station <NUM> may configure an RRC message to indicate an allowed uplink transmission pattern that may be designed to guarantee long-term compliance with the SAR requirement over a particular period (e.g., a few milliseconds). For example, while the UE <NUM> is in an RRC connected state, the base station <NUM> may configure an RRC IE that includes a quantity of slots and/or symbols available for FDD uplink transmission over the particular period, a maximum allowed transmit power that the UE <NUM> can use during the particular period, and/or the like. In this way, configuring the RRC message may guarantee long-term compliance with the SAR requirement over a longer period with less configuration overhead than the DCI message, which may conserve resources that the base station <NUM> would otherwise consume configuring and transmitting multiple DCI messages, network resources that would otherwise be consumed to transport or otherwise communicate the multiple DCI messages, resources that the UE <NUM> would otherwise consume receiving, decoding, and acting on the multiple DCI messages, and/or the like.

As further shown in <FIG>, and by reference number <NUM>, the base station <NUM> may transmit, and the UE <NUM> may receive, a single scheduling message related to activating the uplink transmission pattern configured by the base station <NUM>. For example, in some aspects, the single scheduling message may include an RRC message related to uplink SPS scheduling, a DCI message to activate an uplink transmission pattern indicated in a previous RRC message, and/or the like. For example, the RRC message may indicate a scheduling periodicity, an expiration timer, a resource configuration, and/or the like for each band, carrier, and/or the like associated with the uplink SPS scheduling. Additionally, or alternatively, in cases where the single scheduling message is a DCI message to activate an uplink transmission pattern indicated in a previous RRC message, the previous RRC message may indicate the scheduling periodicity and expiration timer for each band, carrier, and/or the like, and the DCI message may indicate the resource configuration for each band, carrier, and/or the like. Furthermore, in some aspects, the DCI message may include an SPS-RNTI that is included in the content of the DCI message, scrambled with a CRC associated with the DCI message, and/or the like.

Additionally, or alternatively, the single scheduling message that is transmitted by the base station <NUM> and received by the UE <NUM> may include an RRC message with a specific IE related to an uplink configured grant. For example, as described elsewhere herein, the IE included in the RRC message may include a list of frequencies, bands, carriers, and/or the like associated with the uplink configured grant, a resource configuration and slot-level time offset for each frequency, band, and/or carrier, and/or the like (e.g., slots that are available and/or unavailable for uplink transmissions, and/or the like).

Additionally, or alternatively, the single scheduling message that is transmitted by the base station <NUM> and received by the UE <NUM> may include a DCI message that indicates an allowed uplink transmission pattern to be in effect until a next scheduling message to guarantee short-term compliance with an SAR requirement, an RRC message that indicates an allowed uplink transmission pattern to be in effect for a particular period to guarantee long-term compliance with the SAR requirement, and/or the like. For example, as described elsewhere herein, the allowed uplink transmission pattern may include information to indicate a quantity of slots and/or symbols that are available for uplink transmissions, a maximum allowed transmit power, and/or the like.

As further shown in <FIG>, and by reference number <NUM>, the UE <NUM> may transmit information in one or more available uplink symbols that are identified based at least in part on the cross-carrier uplink transmission pattern indicated in the single scheduling message. For example, when a DCI message is received to activate an uplink SPS configuration, the UE <NUM> may identify the SPS-RNTI that is included in the DCI content, scrambled with the CRC, and/or the like to identify the resources (e.g., symbols, RBs, and/or the like) to be used for uplink transmissions via the Pcell operating in the TDD mode, the Scell(s) operating in the FDD and/or TDD mode, and/or the like.

Additionally, or alternatively, when an RRC message is received to provide a band-specific uplink configured grant IE, the UE <NUM> may identify the frequencies and/or bands, the frequency and time resources for each frequency and/or band, slot-level offset, and/or the like based at least in part on one or more fields or elements included in the IE, as described elsewhere herein. Furthermore, the UE <NUM> may perform one or more repetitions of the transmissions in one or more consecutive slots that are indicated as available in the uplink configured grant IE, avoid performing repetitions of the transmissions in one or more slots that are indicated as unavailable in the uplink configured grant IE, and/or the like.

Additionally, or alternatively, when a DCI scheduling message, an RRC scheduling message, and/or the like is received to indicate an allowed uplink transmission pattern designed to guarantee short-term and/or long-term compliance with an SAR requirement, the UE <NUM> may derive a pattern (e.g., quantity) of slots or symbols that are available for uplink transmissions based at least in part on the values indicated in the scheduling message. Furthermore, in some aspects, the UE <NUM> may prioritize certain channels when deriving the slots or symbols. For example, in some aspects, the UE <NUM> may prioritize a physical uplink control channel (PUCCH), a physical random access channel (PRACH), a sounding reference signal (SRS) channel, and/or the like, which the UE <NUM> may prioritize over a data channel when deriving the pattern of slots or symbols that are available for uplink transmissions.

<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 a base station (e.g., base station <NUM> and/or the like) performs operations associated with uplink cross-carrier scheduling for TDM carrier aggregation.

As shown in <FIG>, in some aspects, process <NUM> may include configuring an uplink transmission pattern related to an uplink transmission resource on multiple component carriers (block <NUM>). For example, the base station (e.g., using controller/processor <NUM>, memory <NUM>, and/or the like) may configure an uplink transmission pattern related to an uplink transmission resource on multiple component carriers, as described above.

As further shown in <FIG>, in some aspects, process <NUM> may include transmitting, to a UE, information related to activating the uplink transmission pattern in a single scheduling message (block <NUM>). For example, the base station (e.g., using controller/processor <NUM>, memory <NUM>, transmit processor <NUM>, TX MIMO processor <NUM>, MOD <NUM>, antenna <NUM>, and/or the like) may transmit, to a UE, information related to activating the uplink transmission pattern in a single scheduling message, as described above.

In a first aspect, the single scheduling message is a DCI message or an RRC message.

In a second aspect, alone or in combination with the first aspect, the single scheduling message is an RRC message that includes at least a scheduling periodicity and information related to an expiration timer for each of the multiple component carriers based at least in part on the uplink transmission resource relating to an uplink SPS configuration.

In a third aspect, alone or in combination with one or more of the first and second aspects, the RRC message further includes information related to a resource configuration for each of the multiple component carriers.

In a fourth aspect, alone or in combination with one or more of the first through third aspects, the base station transmits, to the UE, a DCI message that includes information related to a resource configuration for each of the multiple component carriers.

In a fifth aspect, alone or in combination with one or more of the first through fourth aspects, the DCI message is associated with an SPS-RNTI that is included in content of the DCI message or used to scramble a CRC associated with the DCI message.

In a sixth aspect, alone or in combination with one or more of the first through fifth aspects, the single scheduling message is an RRC IE that includes information related to one or more of the multiple component carriers, a resource configuration for each of the multiple component carriers, or a slot-level time offset for each of the multiple component carriers based at least in part on the uplink transmission resource relating to an uplink configured grant configuration.

In a seventh aspect, alone or in combination with one or more of the first through sixth aspects, the RRC IE indicates one or more slots that are unavailable for uplink transmission using the uplink transmission resource.

In an eighth aspect, alone or in combination with one or more of the first through seventh aspects, the single scheduling message is a DCI message comprising information related to a limit on a SAR that is effective until a next scheduling message.

In a ninth aspect, alone or in combination with one or more of the first through eighth aspects, the DCI message includes at least one element to notify the UE that the uplink transmission pattern is to be in effect until the next scheduling message.

In a tenth aspect, alone or in combination with one or more of the first through ninth aspects, the at least one element in the DCI message identifies one or more slots or symbols that are available for uplink transmissions and a maximum allowed uplink transmit power until the next scheduling message.

In an eleventh aspect, alone or in combination with one or more of the first through tenth aspects, the single scheduling message is an RRC message comprising information related to a limit on an SAR when the UE is in an RRC connected state.

In a twelfth aspect, alone or in combination with one or more of the first through eleventh aspects, the RRC message includes at least one IE to identify one or more slots or symbols available for uplink transmissions and a maximum allowed uplink transmit power over a time period.

In a thirteenth aspect, alone or in combination with one or more of the first through twelfth aspects, the information related to activating the uplink transmission pattern enables the UE to derive one or more symbols that are available for uplink transmissions on the multiple component carriers.

In a fourteenth aspect, alone or in combination with one or more of the first through thirteenth aspects, the uplink transmission pattern is based at least in part on hard coded information stored in a memory of the base station or scheduling information that is determined by the base station and transparent to the UE.

<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 a UE (e.g., UE <NUM> and/or the like) performs operations associated with uplink cross-carrier scheduling for time division multiplexing carrier aggregation.

As shown in <FIG>, in some aspects, process <NUM> may include receiving, from a base station, a single scheduling message including information related to activating an uplink transmission pattern related to an uplink transmission resource on multiple component carriers (block <NUM>). For example, the UE (e.g., using antenna <NUM>, DEMOD <NUM>, MIMO detector <NUM>, receive processor <NUM>, controller/processor <NUM>, memory <NUM>, and/or the like) may receive, from a base station, a single scheduling message including information related to activating an uplink transmission pattern related to an uplink transmission resource on multiple component carriers, as described above.

As further shown in <FIG>, in some aspects, process <NUM> may include transmitting information on the multiple component carriers in one or more uplink symbols based at least in part on the uplink transmission pattern (block <NUM>). For example, the UE (e.g., using controller/processor <NUM>, memory <NUM>, transmit processor <NUM>, TX MIMO processor <NUM>, MOD <NUM>, antenna <NUM>, and/or the like) may transmit information on the multiple component carriers in one or more uplink symbols based at least in part on the uplink transmission pattern, as described above.

In a fourth aspect, alone or in combination with one or more of the first through third aspects, the UE receives, from the base station, a DCI message that includes information related to a resource configuration for each of the multiple component carriers.

In an eighth aspect, alone or in combination with one or more of the first through seventh aspects, the single scheduling message is a DCI message comprising information related to a limit on an SAR that is effective until a next scheduling message.

Claim 1:
A method of wireless communication performed by a base station (<NUM>), comprising:
configuring (<NUM>) an uplink transmission pattern related to an uplink transmission resource on multiple component carriers; and
transmitting (<NUM>), to a user equipment, UE (<NUM>), information related to activating the uplink transmission pattern in a single scheduling message,
characterized in that
the single scheduling message is a downlink control information, DCI, message comprising information related to a limit on a specific absorption rate that is effective until a next scheduling message or a radio resource control, RRC, message and comprises information related to a limit on a specific absorption rate when the UE (<NUM>) is in an RRC connected state; and receiving information on the multiple component carriers in one or more uplink symbols based at least in part on the uplink transmission pattern complying with the limit on the specific absorption rate.