Sounding reference signal carrier switching

Abstract

The present disclosure generally relates to sounding reference signal (SRS)-carrier switching (CS) with uplink transmit (Tx) switching. In some implementations, a user equipment (UE) is configured to perform uplink Tx switching between a first component carrier (CC) and a second CC that is shared by a first Tx chain and a second Tx chain. The UE may also be configured to perform SRS-CS on a third CC. The UE may switch at least one of the first Tx chain or the second Tx chain to the third CC in accordance with the SRS-CS configuration. After a switching gap has elapsed, the UE may transmit at least one SRS via an SRS resource set on the third CC.

Description

Attorney Docket No. 56990-0035W01 / P68414WO1SOUNDING REFERENCE SIGNAL CARRIER SWITCHINGCROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority to U.S. Provisional Application No. 63 / 680,208, filed August 7, 2024, the entirety of which is incorporated herein by reference.TECHNICAL FIELD

[0002] This application relates generally to wireless communication, and more specifically to sounding reference signal (SRS)-carrier switching (CS) with uplink transmit (Tx) switching.BACKGROUND

[0003] Wireless communication networks provide integrated communication platforms and telecommunication services to wireless user devices. Example telecommunication services include telephony, data (e.g., voice, audio, and / or video data), messaging, and / or other services. The wireless communication networks have wireless access nodes that exchange wireless signals with the wireless user devices using wireless network protocols, such as protocols described in various telecommunication standards promulgated by the Third Generation Partnership Project (3 GPP). The wireless communication networks facilitate mobile broadband service using technologies such as orthogonal frequency-division multiple access (OFDMA) networks, multiple input multiple output (MIMO), advanced channel coding, massive MIMO, beamforming, and / or other features.

[0004] Sounding Reference Signals (SRS) are uplink reference signals transmitted by a user equipment (UE) to a base station. The base station uses SRS to perform channel quality estimation, e.g., by determining channel state information (CSI), for the uplink channel. The base station configures the UE with an SRS configuration that specifies parameters that dictate how and when the UE transmits SRS. In particular, the SRS configuration specifies SRS resources that define the resource elements that the UE is to use for SRS. SRS resources can be grouped into SRS resource sets.

[0005] One type of SRS is called SRS-Antenna Switching (SRS-AS). SRS-AS is an SRS resource set in which the UE alternately transmits SRS from different antenna ports. This allows the base station to measure (or “sound”) the uplink channel quality for the different antenna paths. The time it takes for the UE to switch between antenna ports is called an “antenna switching time,” which can be, e.g., 15 microseconds (us) or 1 symbol. The SRSAttorney Docket No. 56990-0035W01 / P68414WO1 configuration can specify that a usage for the SRS is “antennaSwitching.” The SRS configuration can also specify the number antenna ports for SRS transmission, e.g., two antenna ports.

[0006] In a time-division duplex (TDD) system, the uplink and downlink channels are similar because they share the same frequency band. This means that the channel characteristics measured for the uplink (from UE to base station) can be applied to optimize the downlink (from base station to UE). As explained, when the UE transmits SRS, the base station uses this signal to assess the uplink channel quality. Due to channel reciprocity in TDD systems, the base station can also use the uplink CSI to infer downlink CSI. Thus, in TDD bands with channel reciprocity, SRS transmission by a UE can be used by the base station to determine CSI for the downlink channel.

[0007] If the UE does not have the same number of transmit branches (also called transmit or Tx chains) as receive branches (also called receive or Rx chains), the UE can be configured with SRS-AS to sound the channel quality of the different receive branches by transmitting SRS from different antenna ports. For example, a UE with 1 transmit branch (ITx) and 2 receive branches (2Rx) can be configured to antenna switch between two antenna ports to accurately sound the channel quality for the different receive paths. This configuration is called 1T2R. Other configurations include 1T4R and 2T4R.Attorney Docket No. 56990-0035W01 / P68414WO1BRIEF DESCRIPTION OF THE FIGURES

[0008] FIG. 1 illustrates a wireless network, according to some implementations.

[0009] FIG. 2 illustrates an example specified Sounding Reference Signal (SRS)-carrier switching (CS) and transmitter (Tx) chain switching scenario, according to some implementations.

[0010] FIG. 3 illustrates example alternatives for determining whether to prioritize the uplink carrier transmission or SRS-CS, according to some implementations.

[0011] FIG. 4A and FIG. 4B each illustrate example carrier switching timelines, according to some implementations.

[0012] FIG. 5 A illustrates example alternatives for determining whether to prioritize an uplink carrier transmission or SRS-CS, according to some implementations.

[0013] FIG. 5B illustrates example alternatives for determining the order between applying uplink Tx switching and SRS-CS prioritization rules, according to some implementations.

[0014] FIG. 5C illustrates additional example alternatives for determining whether to prioritize an uplink carrier transmission or SRS-CS, according to some implementations.

[0015] FIG. 6 illustrates an example Mode 2 SRS-CS timeline, according to some implementations.

[0016] FIG. 7A and 7B each illustrate parallel SRS-CS and uplink transmission scenarios, according to some implementations.

[0017] FIGs. 8A-8E illustrate flowcharts of example methods, according to some implementations.

[0018] FIG. 9 illustrates an example user equipment (UE), according to some implementations.

[0019] FIG. 10 illustrates an example access node, according to some implementations.Attorney Docket No. 56990-0035W01 / P68414WO1DETAILED DESCRIPTION

[0020] In accordance with 3rd Generation Partnership Project (3GPP) Technical Specification (TS), Sounding Reference Signal (SRS)-carrier switching (CS) may be used to obtain downlink channel state information (CSI) on a Physical Uplink Shared Channel (PUSCH)-less component carrier (CC). This feature can be employed in scenarios where one of the carriers is configured for downlink reception only. In these scenarios, SRS-CS enables a UE to switch from a source carrier (or source cell) to a target carrier (or target cell), which is not configured for uplink transmission, to transmit SRS to the base station on the target carrier. Doing so enables the base station to derive CSI for the downlink carrier (using the principle of reciprocity described above). Although 3GPP specifications cover some aspects of SRS-CS, there are several issues related to SRS-CS that have not yet been addressed.

[0021] This disclosure describes solutions for SRS transmission on a target carrier using SRS- CS. One solution is related to a scenario where a user equipment (UE) is configured to perform SRS-CS and uplink transmit (Tx) chain switching. In this configuration, the UE performs uplink Tx chain switching between a first CC (CC1) and a second CC (CC2), and carrier switching to a PUSCH-less third CC (CC3) to transmit SRS on CC3. Another solution relates to extending uplink carrier aggregation (CA) to include SRS transmissions on a target carrier.

[0022] FIG. 1 illustrates a wireless network 100, according to some implementations. The wireless network 100 includes a UE 102 and a base station 104 connected via one or more channels 106A, 106B across an air interface 108. The UE 102 and base station 104 communicate using a system that supports controls for managing the access of the UE 102 to a network via the base station 104.

[0023] In some implementations, the wireless network 100 may be a Standalone (SA) network that incorporates Fifth Generation (5G) New Radio (NR) communication standards as defined by the Third Generation Partnership Project (3GPP) technical specifications. In some other implementations, Non- Standalone (NS A) network that incorporates both Long Term Evolution (LTE) and 5G NR. For example, the wireless network 100 may be a E-UTRA (Evolved Universal Terrestrial Radio Access)-NR Dual Connectivity (EN-DC) network, or an NR- EUTRA Dual Connectivity (NE-DC) network. Furthermore, other types of communication standards are possible, including future 3 GPP systems (e.g., Sixth Generation (6G)), Institute of Electrical and Electronics Engineers (IEEE) 802.11 technology, or the like. While aspects may be described herein using terminology commonly associated with 5G NR, aspects of theAttorney Docket No. 56990-0035W01 / P68414WO1 present disclosure can be applied to other systems, such as 4G and / or systems subsequent to 5G (e.g., 6G).

[0024] In the wireless network 100, the UE 102 and any other UE in the system may be, for example, any of laptop computers, smartphones, tablet computers, machine-type devices such as smart meters or specialized devices for healthcare, intelligent transportation systems, or any other wireless device. In network 100, the base station 104 provides the UE 102 network connectivity to a broader network (not shown). This UE 102 connectivity is provided via the air interface 108 in a base station service area provided by the base station 104. In some implementations, such a broader network may be a wide area network operated by a cellular network provider, or may be the Internet. Each base station service area associated with the base station 104 is supported by one or more antennas integrated with the base station 104. The service areas can be divided into a number of sectors associated with one or more particular antennas. Such sectors may be physically associated with one or more fixed antennas or may be assigned to a physical area with one or more tunable antennas or antenna settings adjustable in a beamforming process used to direct a signal to a particular sector.

[0025] The UE 102 includes control circuitry 110 coupled with transmit circuitry 112 and receive circuitry 114. The transmit circuitry 112 and receive circuitry 114 may each be coupled with one or more antennas. The control circuitry 110 may include various combinations of application-specific circuitry and baseband circuitry. The transmit circuitry 112 and receive circuitry 114 may be adapted to transmit and receive data, respectively, and may include radio frequency (RF) circuitry and / or front-end module (FEM) circuitry.

[0026] In various implementations, aspects of the transmit circuitry 112, receive circuitry 114, and control circuitry 110 may be integrated in various ways to implement the operations described herein. The control circuitry 110 may be adapted or configured to perform various operations, such as those described elsewhere in this disclosure related to a UE. The transmit circuitry 112 can perform various operations described in this specification. Additionally, the transmit circuitry 112 may transmit using a plurality of multiplexed uplink physical channels. The plurality of uplink physical channels may be multiplexed, e.g., according to time division multiplexing (TDM) or frequency division multiplexing (FDM) along with CA. The transmit circuitry 112 may be configured to receive block data from the control circuitry 110 for transmission across the air interface 108.Attorney Docket No. 56990-0035W01 / P68414WO1

[0027] The receive circuitry 114 can perform various operations described in this specification. Additionally, the receive circuitry 114 may receive a plurality of multiplexed downlink physical channels from the air interface 108 and relay the physical channels to the control circuitry 110. The plurality of downlink physical channels may be multiplexed, e.g., according to TDM or FDM along with CA. The transmit circuitry 112 and the receive circuitry 114 may transmit and receive, respectively, both control data and content data (e.g., messages, images, video, etc.) structured within data blocks that are carried by the physical channels.

[0028] FIG. 1 also illustrates the base station 104. In some implementations, the base station 104 may be a 5G radio access network (RAN), a next generation RAN, a E-UTRAN, a nonterrestrial cell, or a legacy RAN, such as a UTRAN. As used herein, the term “5G RAN” or the like may refer to the base station 104 that operates in an NR or 5G wireless network 100, and the term “E-UTRAN” or the like may refer to a base station 104 that operates in an LTE or 4G wireless network 100. The UE 102 utilizes connections (or channels) 106A, 106B, each of which includes a physical communications interface or layer.

[0029] The base station 104 circuitry may include control circuitry 116 coupled with transmit circuitry 118 and receive circuitry 120. The transmit circuitry 118 and receive circuitry 120 may each be coupled with one or more antennas that may be used to enable communications via the air interface 108. The transmit circuitry 118 and receive circuitry 120 may be adapted to transmit and receive data, respectively, to any UE connected to the base station 104. The receive circuitry 120 may receive a plurality of uplink physical channels from one or more UEs, including the UE 102.

[0030] In FIG. 1, the one or more channels 106 A, 106B are illustrated as an air interface to enable communicative coupling, and can be consistent with cellular communications protocols, such as a 3 GPP LTE protocol, an Advanced long term evolution (LTE- A) protocol, a LTE- based access to unlicensed spectrum (LTE-U), a 5G protocol, a NR protocol, an NR-based access to unlicensed spectrum (NR-U) protocol, and / or any other communications protocol(s). In implementations, the UE 102 may directly exchange communication data via a ProSe interface. The ProSe interface may alternatively be referred to as a sidelink (SL) interface and may include one or more logical channels, including but not limited to a Physical Sidelink Control Channel (PSCCH), a Physical Sidelink Discovery Channel (PSDCH), and a Physical Sidelink Broadcast Channel (PSBCH).Attorney Docket No. 56990-0035W01 / P68414WO1

[0031] In some implementations, UE 102 is configured to perform UL Tx chain switching in CA, Supplementary Uplink (SUL), or NSA (e.g., EN-DC). Tx chain switching involves UE 102 dynamically changing an uplink transmission path from one carrier to another. As an example, if UE 102 has two Tx chains (2Tx), the UE can switch at least one of the Tx chains from one carrier to another. The Tx chain switching can be Dual UL or switched UL. Dual UL allows UE 102 to simultaneously transmit uplink signals on two different carriers, utilizing separate transmission chains for each carrier. Switched UL, on the other hand, does not involve simultaneously transmission of uplink signals. Rather, UE 102 transmits on one carrier at a time.

[0032] In some implementations, UE 102 receives an indication from base station 104 instructing the UE to perform Tx chain switching between (carrier 1, carrier2), where carrier2 supports 2 Tx chains (by default). In this arrangement, the UE 102 can switch one of the two Tx chains from CC2 to CC1 to transmit on CC1. When both Tx chains are assigned to CC2, the state of the Tx chain switching is 0Tx+2Tx, i.e., both Tx chains are with the source carrier. And when one of the Tx chains is assigned to CC1, the state of the Tx chain switching is ITx+lTx, i.e., one chain is with the source carrier and another chain is with a switched carrier. The indication from base station 104 can also include uplinkTxSwitchingPeriod, which is a parameter that specifies the time for switching the Tx chain from carrier to another. The uplinkTxSwitchingPeriod, which can have units of microseconds (us), can be one of {n35us, nl40us, n210us}. Note that the network can configure which carrier, by default, is assigned or allocated 2 Tx chains and which carrier borrows a Tx chain.

[0033] In some implementations, UE 102 is configured to perform UL Tx chain switching and SRS-CS. In these implementations, UE 102 also receives an indication e.g., SRS- Carrier Switching, from base station 104 instructing the UE to perform SRS-CS for a PUSCH- less third carrier (carriers). In some examples, there are two modes for SRS-CS and Tx chain switching. In the first mode, called “Mode 1 SRS-CS” or “CC2-to-CC3 Switching,” the SRS- CS is configured between CC2 and CC3. In this mode, to transmit SRS on CC3, UE 102 switches one or more Tx chains from CC2 (source carrier) to CC3 (target carrier). In the second mode, called “Mode 2 SRS-CS” or “CCl-to-CC3 Switching,” the SRS-CS is configured between CC1 and CC3. In this mode, to transmit SRS on CC3, UE 102 switches one or more Tx chains from CC1 (source carrier) to CC3 (target carrier).Attorney Docket No. 56990-0035W01 / P68414WO1

[0034] In line with the discussion above, this disclosure describes solutions for SRS-CS and Tx chain switching. Among other things, this disclosure describes prioritization rules not only between the source carrier (e.g., CC2 or CC1) and the target carrier (e.g., CC3), but also between the other carrier(s) in the Tx chain switching configuration (e.g., the other one of CC2 or CC1). Additionally, this disclosure describes timelines, including required gaps, to achieve SRS-CS and Tx chain switching. Note that this disclosure describes solutions for both SRS-CS modes: Mode 1 SRS-CS and Mode 2 SRS-CS. Also note that for the purposes of this disclosure, CC2 and CC1 are also referred to as uplink carriers and CC3 is also referred to as a downlink carrier.

[0035] FIG. 2 illustrates an example SRS-CS and Tx chain switching scenario 200, according to some implementations. In scenario 200, UE 102 (not illustrated) is indicated to perform Tx chain switching between carrier2 (C2) and carrierl (Cl), where carrier2 is assigned two Tx chains. To do so, UE 102 switches one of C2’s Tx chains to Cl to transmit uplink messages on Cl. In scenario 200, the starting or current state of Tx chain switching is ITx+lTx because UE 102 has switched one Tx chain to Cl to transmit a 1 antenna port physical uplink control channel (PUCCH) 202.

[0036] Additionally, UE 102 is indicated to perform SRS-CS using Mode 1 SRS-CS to transmit SRS on PUSCH-less C3 (i.e., DL only carrier). In this mode, UE 102 switches one or more Tx chains from C2 to C3 to transmit SRS on C3. UE 102 is also configured with SRS- SwitchingTimeNR, which specifies the interruption time on DL / UL reception within a band pair during the RF retuning for switching between a carrier on one band and another (PUSCH- less) carrier on the other band to transmit SRS. The SRS-SwitchingTimeNR can be one of {nOus, n30us, nlOOus, nl40us, n200us, n300us, n500us, n900us}. In scenario 200, SRS 204 is 2 port SRS- AS, and therefore, UE 102 needs to switch both Tx chains to C3 to transmit the SRS.

[0037] In some implementations, a switching gap 206 between the end of an UL transmission on Cl or C2 (e.g., 1 port PUCCH 202) and the SRS-CS transmission on C3 (e.g., 2 port SRS 204) is specified. The length of the switching gap 206 can be determined using one of two alternatives. In a first alternative, the switching gap 206 is at least uplinkTxSwitchingPeriod + SRS-SwitchingTimeNR. This alternative is applicable in scenarios where UE 102 is configured to first return the Tx chain to C2 and then switch both Tx chains to C3. In a second alternative, the switching gap 206 is at least SRS-SwitchingTimeNR. This alternative is applicable in scenarios where UE 102 is configured to directly and / or in parallel switch Tx chains fromAttorney Docket No. 56990-0035W01 / P68414WO1C1 / C2 to C3. Because the switching gap 206 is dependent on whether UE 102 is configured to first return the Tx chain to C2 or to directly and / or in parallel switch Tx chains from C1 / C2, the alternative that the UE applies in a particular scenario is subject to UE capability.

[0038] As represented by arrow 208, after the SRS 204 transmission is complete, UE 102 switches the Tx chains back to Cl and / or C2. In some implementations, UE 102 is configured with one or more alternatives that specify how the UE returns the Tx chains to the uplink carriers (e.g., Cl and / or C2). In a first alternative, UE 102 switches the Tx chains back to the source carrier (C2 in scenario 200). In this alternative, an RF tuning time 210 to switch from C3 to C2 is SRS-SwitchingTimeNR, and the new state in the Tx chain switching is 0Tx+2Tx. In a second alternative, UE 102 switches the Tx chains back to the arrangement before the SRS-CS transmission on C3. In scenario 200, UE 102 switches 1 Tx chain back to Cl and the other Tx chain back to C2. Thus, the new state in the Tx chain switching is ITx+lTx, which was the state before the SRS-CS transmission. The RF tuning time 210 for this alternative depends on the new state, and can be uplinkTxSwitchingPeriod + SRS-SwitchingTimeNR or SRS-SwitchingTimeNR.

[0039] In some implementations, an overall timeline for transmitting SRS-AS resources within an SRS resource set on a target carrier is specified. In these implementations, an uplink channel transmission on Cl or C2 is considered to be overlapping with the SRS-AS transmission if the uplink transmission overlaps with any portion, e.g., symbol, of the SRS-AS timeline. In some examples, the SRS-AS timeline includes: (i) a gap to switch the Tx chains (from the uplink carriers) to the target (downlink) carrier, e.g., the switching gap 206; (ii) a number of symbols for each SRS resource transmission; (iii) an SRS antenna switching gap between two SRS resources within an SRS resource set, e.g., as given by Table 6.2.1.2-1 in TS 38.214; and / or (iv) a gap to switch the Tx chains to the uplink carriers, e.g., RF tuning time 210.

[0040] In some scenarios, UE 102 may be scheduled for an uplink transmission on an uplink carrier (Cl or C2) that overlaps with SRS-CS on the target carrier (C3). In these scenarios, if the SRS resource set on the target carrier is configured with 2 antenna ports, then UE 102 cannot send the uplink transmission (e.g., PUCCH on Cl) and SRS-AS on C3 (including any RF retuning time) in parallel. Conversely, if the SRS resource set on the target carrier is configured with 1 antenna port, then UE 102 can send the uplink transmission (e.g., PUCCH on Cl) and SRS-AS on C3 (including any RF retuning time) in parallel, subject to certain conditions (described in more detail below).Attorney Docket No. 56990-0035W01 / P68414WO1

[0041] As stated, if the SRS on the target carrier is 2 port SRS-AS, then UE 102 cannot send an uplink transmission on an uplink carrier and SRS-CS on the target carrier in parallel. In some implementations, UE 102 is configured with at least one of several alternatives for determining whether to prioritize the uplink carrier transmission or SRS-CS. In a first alternative, UE 102 prioritizes the uplink carrier transmission (on Cl and / or C2) and drops the overlapping SRS-CS. In a second alternative, UE 102 deprioritizes the uplink carrier transmission (on Cl and / or C2) and transmits the overlapping SRS-CS. In a third alternative, UE 102 applies prioritization rules to determine whether to prioritize uplink carrier transmission (on Cl and / or C2) or the overlapping SRS-CS. The prioritization rules can be configured by base station 104 or preconfigured in specification. In this alternative, UE 102 uses the (pre-)configured prioritization rules to compare a priority of the uplink carrier transmission (s) on Cl and / or C2 to a priority of the overlapping SRS-CS to select one for transmission. As an example, if the uplink carrier transmission on Cl is PUCCH with Periodic- CSI (P-CSI) only, UE 102 prioritizes SRS-CS and drops the PUCCH because SRS-CS is higher priority than P-CSI. As another example, if the uplink carrier transmission on Cl is PUCCH with HARQ-ACK, UE 102 prioritizes PUCCH and drops SRS-CS because HARQ-ACK is higher priority than SRS-CS. In sum, if there is any uplink carrier transmission (in any uplink carrier) that is higher priority than SRS-CS on the target carrier, UE 102 drops SRS-CS.

[0042] FIG. 3 illustrates example alternatives for determining whether to prioritize the uplink carrier transmission or SRS-CS, according to some implementations. Like in FIG. 2, UE 102 (not illustrated) is configured with Mode 1 SRS-CS and Tx chain switching between Cl and C2. As shown in FIG. 3, PUCCH 302 scheduled on Cl overlaps with SRS-CS 304 on C3. As also shown, SRS-CS 304 on C3 is 2 port SRS-AS, and the starting Tx chain switching state is 0Tx+2Tx. The alternatives for determining whether to prioritize PUCCH 302 or SRS-CS 304 are illustrated in FIG. 3. According to the first alternative, UE 102 prioritizes PUCCH 302 and drops SRS-CS 304. Here, the Tx chain switching state becomes ITx+lTx to allow UE 102 to transmit PUCCH 302 on Cl. According to the second alternative, UE 102 prioritizes SRS-CS 304 and drops PUCCH 302. Here, the Tx chain switching state remains 0Tx+2Tx to allow UE 102 to transmit SRS-CS 304 on C3. And according to the third alternative, UE 102 applies prioritization rules to determine which transmission to prioritize. Here, the new Tx chain switching state depends on which one of PUCCH 302 and SRS-CS 304 is prioritized.

[0043] In some implementations, UE 102 is configured with conditions for dropping an uplink carrier transmission (e.g., on Cl and / or C2) or SRS-CS (on C3). The conditions for droppingAttorney Docket No. 56990-0035W01 / P68414WO1 an uplink carrier transmission are explained in FIG. 4A and the conditions for dropping SRS- CS are explained in FIG. 4B.

[0044] FIG. 4A illustrates an example carrier switching timeline 400, according to some implementations. In this example, UE 102 (not illustrated) is scheduled to transmit PUCCH 402 on Cl at time TO. As shown in FIG. 4A, UE 102 receives downlink control information (DCI) 406 (e.g., DCI 2 3) that schedules SRS-CS 404 on C3 at a time that overlaps with PUCCH 402. For the purposes of this example, assume that UE 102 determines to drop PUCCH 402 and prioritize SRS-CS 404 (e.g., using one of the alternatives described above).

[0045] In some implementations, UE 102 determines whether one or more conditions are satisfied to drop PUCCH 402. A first condition is that PUCCH 402 is scheduled by a configured grant and not by a dynamic grant. A second condition is that UE 102 receives the cancellation DCI (e.g., DCI 406) at least by T0-Tproc,2, where Tproc,2 is the UE PUSCH preparation procedure time. If the starting Tx chain switching state is 0Tx+2Tx, Tproc,2 includes Tswitch, which is the switching gap duration for Tx switching from C2 to Cl. And if the starting Tx chain switching state is ITx+lTx, Tproc,2 does not include Tswitch.

[0046] The calculation of Tproc,2 is described in TS 38.214, Clause 6.4. As explain in that clause, the calculation of Tproc,2 for the UE PUSCH preparation procedure time involves several factors and conditions. It is determined as the maximum value after the reception of the last symbol of the physical downlink control channel (PDCCH) carrying the DCI scheduling the PUSCH and is derived from the formula:Tproc,2=max ((N2+d2,l+d2)(2048+144)- K2^-Tc+TeXt+TSwiteh,d2,2)Here, K2 is the slot offset and N2 is based on the tables (Tables 6.4-1 and 6.4-2 in TS 38.214) for UE processing capability 1 and 2, and depends on the subcarrier spacing p and whether shared spectrum channel access or multiple active component carriers are configured, p corresponds to the one of (pDL, pUL) resulting with the largest Tproc,2, where the pDL corresponds to the subcarrier spacing of the downlink with which the PDCCH carrying the DCI scheduling the PUSCH was transmitted and pUL corresponds to the subcarrier spacing of the uplink channel with which the PUSCH is to be transmitted, and K is defined in clause 4.1 of TS 38.211. Various conditions, such as the presence of DM-RS only, switching of bandwidth parts (BWP), and overlapping PUSCH with PUCCH of different priority indices, impact the values of d2,l and d2,2. If the first symbol of the PUSCH allocation consists of DM-RS only, then d2, 1 = 0, otherwise d2, 1 = 1. If the scheduling DCI triggered a switch of BWP, d2,2 equalsAttorney Docket No. 56990-0035W01 / P68414WO1 to the switching time as defined in TS 38.133, otherwise d2,2=0. If aPUSCH of a larger priority index would overlap with PUCCH of a smaller priority index, d2 for the PUSCH of a larger priority is set as reported by the UE; otherwise d2 = 0. For operation with shared spectrum channel access, Text is calculated according to TS 38.211], otherwise Text =0.

[0047] FIG. 4B illustrates an example carrier switching timeline 410, according to some implementations. In this example, UE 102 (not illustrated) is scheduled to transmit SRS-CS on C3 412 on C3 at time TO. As shown in FIG. 4B, UE 102 receives DCI 416 (e.g., DCI 1 1) that schedules PUCCH 414 on Cl at a time that overlaps with SRS-CS 412. For the purposes of this example, assume that UE 102 determines to drop SRS-CS 412 and prioritize PUCCH 414 (e.g., using one of the alternatives described above).

[0048] In some implementations, UE 102 determines whether one or more conditions are satisfied to drop SRS-CS 412. A first condition is that SRS-CS 412 is not triggered by a dynamic grant. A second condition is that UE 102 receives the cancellation DCI (e.g., DCI 416) at least by T0-Tproc,2, where TO represents the earliest symbol between SRS-CS 412 (including any RF switching / tuning time) and PUCCH 414. Note that if the starting Tx chain switching state is ITx+lTx, the RF tuning time before the SRS starting symbol can be greater than the case in which the starting state is 0Tx+2Tx. This is because in 0Tx+2Tx both Tx chains are already in the source carrier (i.e., C2), but in ITx+lTx, one of Tx chains is in Cl.

[0049] In some implementations, if UE 102 determines to transmit SRS-CS on a target carrier starting from TO, the network cannot trigger any uplink carrier transmission on Cl or C2 that starts before the end of SRS-CS on the target carrier (including any RF retuning time from the target carrier), where the UE receives the corresponding uplink indication after TO-Nx. Here, Nx is the last symbol of the DCI triggering SRS-CS on the target carrier.

[0050] As stated above, if the SRS resource set on the target carrier is configured with 1 antenna port, then UE 102 can send an uplink carrier transmission (e.g., PUCCH on Cl) and SRS- AS on C3 (including any RF retuning time) in parallel, subject to certain conditions.

[0051] In some implementations, UE 102 is configured with at least one of several alternatives for determining whether to transmit the uplink transmission or the 1 port SRS-CS. In a first alternative, UE 102 does not apply prioritization rules to select between the uplink transmission and the 1 port SRS-CS. In this alternative, UE 102 is instead configured to simultaneously transmit the uplink transmission (e.g., PUCCH on Cl) and SRS-AS on C3. To do so, UE 102 switches 1 Tx chain to C3 (to transmit SRS-CS) and 1 Tx chain to the carrier with an uplinkAttorney Docket No. 56990-0035W01 / P68414WO1 transmission (e.g., Cl). Thus, the Tx chain switching state of UE 102 becomes ITx+lTx. In a second alternative, UE 102 applies prioritization rules to select between the uplink carrier transmission and the SRS-CS. In this alternative, the Tx chain switching state of UE 102 depends on the transmission with the higher priority.

[0052] FIG. 5 A illustrates example alternatives for determining whether to prioritize an uplink carrier transmission or SRS-CS, according to some implementations. Here, the starting Tx chain switching state is 0Tx+2Tx and the SRS on the target carrier is 1 port SRS-AS. As shown by timeline 500, PUCCH 502 on Cl overlaps with SRS-AS 504 on C3. In the first alternative, UE 102 does not apply prioritization rules to select between PUCCH 502 and SRS-AS 504. Instead, UE 105 uses respective Tx chains to transmit both PUCCH 502 and SRS-AS 504. In the second alternative, UE 102 applies prioritization rules to select between PUCCH 502 and SRS-AS 504 to prioritize for transmission.

[0053] FIG. 5B illustrates example alternatives for determining the order between applying uplink Tx switching and SRS-CS prioritization rules, according to some implementations. This explains the scenario when the starting Tx chain switching state is ITx+lTx and the SRS on the target carrier is 1 port SRS-AS. As shown by timeline 510, PUCCH 512 on Cl overlaps with SRS-AS 514 on C3. In the first alternative, if UE 102 is capable of parallel transmission, the UE is configured to not apply prioritization rules. Instead, UE 105 uses respective Tx chains to transmit both PUCCH 512 and SRS-AS 514, and the state remains ITx+lTx. In the second alternative, UE 102 applies prioritization rules to select between PUCCH 512 and SRS-AS 514 to prioritize for transmission. In this alternative, the state also remains ITx+lTx but only one of PUCCH 512 and SRS-AS 514 is transmitted.

[0054] FIG. 5C illustrates example alternatives for determining the order between applying uplink Tx switching and SRS-CS prioritization rules, according to some implementations. This addresses the scenario where an uplink transmission that requires uplink Tx switching overlaps with an SRS-CS transmission. In the example of FIG. 5C, the starting state is ITx+lTx and the SRS on C3 is 2 port SRS-AS. As shown by timeline 520, SRS 524 is scheduled on C3 at a time TG2 after P-CSI 522 on Cl. As also shown by timeline 520, a configured grant (CG) PUSCH 526 is scheduled on C2 at a time TGI after P-CSI 522 on Cl. For the purposes of this example, assume that TGI is less than Tswitch and TG2 is enough for the UE to switch the Tx chains to C3 if CG-PUSCH did not exist. But because TGI is less than Tswitch, there is a conflict betweenAttorney Docket No. 56990-0035W01 / P68414WO1P-CSI 522 and CG PUSCH 526. And because SRS 524 is a 2 port SRS that overlaps with CG PUSCH 526, there is a conflict between CG PUSCH 526 and SRS 524.

[0055] In the first alternative, UE 102 is configured to first resolve UL TX switching and then to apply SRS-CS prioritization. Applying the first alternative to timeline 520, UE 102 first resolves UL Tx switching by selecting the higher priority of P-CSI 522 and CG PUSCH 526. Here, UE 102 drops CG PUSCH 526. Then, UE 102 applies SRS-CS prioritization. Because there is no conflict between P-CSI 522 and SRS 524, both are transmitted. In the second alternative, UE 102 is configured to first apply SRS-CS prioritization and then resolve UL TX switching. Applying the second alternative to timeline 520, UE 102 first apply SRS-CS prioritization by selecting between SRS 524 and CG PUSCH 526. Here, UE 102 drops SRS 524. Then, UE 102 resolves UL Tx switching. Here, UE 102 drops CG PUSCH 526.

[0056] As stated above, in Mode 2 SRS-CS, the SRS-CS is configured between CC1 and CC3. Thus, to transmit SRS on CC3 in this mode, UE 102 switches one or more Tx chains from CC1 (source carrier) to CC3 (target carrier). Note that in this mode, an SRS resource set on target with usage as ‘antennaSwitching’ can only be configured with 1 antenna port. Thus, the SRS- CS on target initiates the Tx switching state to change from 0Tx+2Tx to ITx+lTx, where ITx is assigned to Cl and ITx is assigned to C3.

[0057] FIG. 6 illustrates an example Mode 2 SRS-CS timeline 600, according to some implementations. In this example, to transmit SRS 602 on CC3, UE 102 switches one or more Tx chains from CC1 (source carrier) to CC3 (target carrier). If the starting Tx chain switching state is 0Tx+2Tx, then the SRS-CS timeline 600 includes a switching period 604 (also labelled NTX1-TX2) for switching a Tx chain from C2 to Cl and a switching period 606 (also labelled NTX1-TX2) for switching the Tx chain from Cl back to C2. Note that 2 port transmission on CC2 is not possible within the SRS-CS timeline 600.

[0058] In some implementations, UE 102 is configured with at least one of several alternatives for determining whether to prioritize an uplink carrier transmission on C2 or SRS-CS when they overlap (i.e., when an uplink carrier transmission on C2 overlaps with the SRS-CS timeline 600). In a first alternative, UE 102 prioritizes the uplink carrier transmission (on C2) and drops the overlapping SRS-CS. In a second alternative, UE 102 deprioritizes the uplink carrier transmission (on C2) and transmits the overlapping SRS-CS. In a third alternative, UE 102 applies prioritization rules to determine whether to prioritize uplink carrier transmission (on C2) or the overlapping SRS-CS. The prioritization rules can be configured by base stationAttorney Docket No. 56990-0035W01 / P68414WO1104 or preconfigured in specification. In this alternative, UE 102 uses the (pre-)configured prioritization rules to compare a priority of the uplink carrier transmission(s) on C2 to a priority of the overlapping SRS-CS to select one for transmission. As an example, if the uplink carrier transmission on C2 is PUCCH with Periodic-CSI (P-CSI) only, UE 102 prioritizes SRS-CS and drops the PUCCH because SRS-CS is higher priority than P-CSI. As another example, if the uplink carrier transmission on C2 is PUCCH with HARQ-ACK, UE 102 prioritizes PUCCH and drops SRS-CS because HARQ-ACK is higher priority than SRS-CS. In sum, if there is any uplink carrier transmission (in any uplink carrier) that is higher priority than SRS-CS on the target carrier, UE 102 drops SRS-CS.

[0059] In some implementations, UE 102 determines whether one or more conditions are satisfied to drop uplink carrier transmission on C2. A first condition is that the uplink carrier transmission is scheduled by a configured grant and not by a dynamic grant. A second condition is that UE 102 receives the cancellation DCI at least before SRS-CS timeline 600.

[0060] In some implementations, UE 102 determines whether one or more conditions are satisfied to drop SRS-CS. A first condition is that SRS-CS is not triggered by a dynamic grant. A second condition is that UE 102 receives the cancellation DCI at least before SRS-CS timeline 600.

[0061] In some implementations, if UE 102 determines to transmit SRS-CS on a target carrier starting from TO, the network cannot trigger any uplink carrier transmission on C2 that starts before the end of SRS-CS on the target carrier (including any RF retuning time from the target carrier), where the UE receives the corresponding uplink indication after TO-Nx. Here, Nx is the last symbol of the DCI triggering SRS-CS on the target carrier.

[0062] In some implementations, uplink CA capabilities are extended to cover simultaneous SRS-CS on target and uplink carrier transmission on another band not impacted by the SRS- CS switching from source to target. UE 102 can transmit the capabilities to inform base station 104 of the UE’s parallel SRS-CS and uplink transmission capabilities. Example capabilities include parallelTxSRS-PUCCH-PUSCH, parallelTxPRACH-SRS-PUCCH-PUSCH, simulTX- SRS-AntSwitchinglnterBandUL-CA-r 16, and simulTX-SRS-AntSwitchinglntraBandUL-CA- rl6. parallelTxSRS-PUCCH-PUSCH indicates whether the UE 102 supports parallel SRS-CS on a target carrier and PUSCH on an uplink carrier that is inter-band with the source carrier; parallelTxPRACH-SRS-PUCCH-PUSCH indicates whether the UE 102 supports parallel SRS- CS on a target carrier and PRACH on an uplink carrier that is inter-band with the source carrier;Attorney Docket No. 56990-0035W01 / P68414WO1 simulTX-SRS-AntSwitchingInterBandUL-CA-rl6 indicates whether the UE 102 supports (i) parallel SRS-CS on a target carrier, and SRS-AS on an uplink carrier, inter-band with the source carrier and inter-band with target carrier or (ii) parallel SRS-CS on target-1, and SRS- CS on target-2, target- 1 and target-2 are inter-band downlink carriers; and simulTX-SRS- AntSwitchinglntraBandUL-CA-r 16 indicates whether the UE 102 supports (i) parallel SRS- CS on target, and SRS-AS on an uplink carrier, inter-band with the source carrier and intraband with the target carrier or (ii) parallel SRS-CS on target-1, and SRS-CS on target-2, target- 1 and target-2 are intra-band downlink carriers.

[0063] In some implementations, for simultaneously transmitting SRS-CS on a target carrier and an SRS-AS on an uplink carrier that is inter (or intra) band with the target carrier, UE 102 can switch bands together subject to a UE capability. In these implementations, UE 102 expects the same configuration of xTyR (i.e., Tx / Rx antenna port configuration) across the different component carriers. Additionally, UE 102 expects that the SRS resources overlapped in time domain from the UE perspective are from the same UE antenna ports.

[0064] FIG. 7A illustrates a parallel SRS-CS and uplink transmission scenario 700, according to some implementations. In scenario 700, UE 102 is capable of performing parallel transmission of SRS-CS on a target carrier (Cl) and SRS-AS on an uplink carrier (C2). As shown in FIG. 7A, UE 102 switches to the target carrier (Cl) from a source carrier (CO). As also shown in FIG. 7A, the SRS resources overlapped in time domain from the UE perspective are from the same UE antenna ports. Further, both SRS use the same configuration of xTyR, which in this example, is 1TX2RX. Finally, note that both SRS use the same guard period between the different antenna port transmissions. In one example, the guard period is 1 symbol.

[0065] FIG. 7B illustrates a parallel SRS-CS and uplink transmission scenario 710, according to some implementations. In scenario 700, UE 102 is capable of performing parallel transmission of SRS-CS on a first target carrier (Cl) and SRS-CS on a second target carrier (C2). As shown in FIG. 7B, UE 102 switches to the first target carrier (Cl) from a first source carrier (CO), and switches to the second target carrier (C2) from a second source carrier (C3). As also shown in FIG. 7B, the SRS resources overlapped in time domain from the UE perspective are from the same UE antenna ports. Further, both SRS use the same configuration of xTyR, which in this example, is 1TX2RX. Finally, note that both SRS use the same guard period, e.g., 1 symbol, between the different antenna port transmissions.Attorney Docket No. 56990-0035W01 / P68414WO1

[0066] FIGs. 8A-8E illustrate flowcharts of example methods, according to some implementations. For clarity of presentation, the description that follows generally describes the methods in the context of the other figures in this description. For example, the methods can be performed by UE 102 of FIG. 1. It will be understood that the methods can be performed, for example, by any suitable system, environment, software, hardware, or a combination of systems, environments, software, and hardware, as appropriate. In some implementations, various steps of the methods can be run in parallel, in combination, in loops, or in any order.

[0067] Starting with FIG. 8A, at 802, method 800 involves receiving a first instruction to uplink transmitter switch between a carrier pair including a first carrier (Cl) and a second carrier (C2), where C2 is assigned to two transmitter chains.

[0068] At 804, method 800 involves receiving a second instruction to perform SRS-CS to transmit an SRS resource set in a third carrier (C3), where the third carrier is a downlink carrier.

[0069] At 806, method 800 involves while in a starting uplink transmitter switching state, transmitting an uplink transmission on the first carrier (Cl).

[0070] At 808, method 800 involves switching the two transmitter chains to the third carrier (C3).

[0071] At 810, method 800 involves after a switching gap has elapsed, transmitting an SRS resource set on the third carrier (C3).

[0072] Turning to FIG. 8B, at 814, method 812 involves receiving a first instruction to uplink transmitter switch between a carrier pair including a first carrier (Cl) and a second carrier (C2), where C2 is assigned to two transmitter chains.

[0073] At 816, method 812 involves receiving a second instruction to perform SRS-CS to transmit a two-antenna port (2-AP) SRS transmission on a third carrier (C3), where the third carrier (C3) is a downlink carrier.

[0074] At 818, method 812 involves determining that a scheduled uplink transmission on the first carrier (Cl) or the second carrier (C2) overlaps with the 2-AP SRS transmission on the third carrier (C3).

[0075] At 820, method 812 involves responsively dropping one of the uplink transmission and the 2-AP SRS transmission.Attorney Docket No. 56990-0035W01 / P68414WO1

[0076] Turning to FIG. 8C, at 824, method 822 involves transmitting a capability indicating that the UE supports a parallel SRS-CS transmission on a first carrier and an uplink transmission on a second carrier.

[0077] At 826, method 822 involves transmitting in parallel the SRS-CS transmission on the first carrier and the uplink transmission on the second carrier.

[0078] Turning to FIG. 8D, at 832, method 830 involves receiving a first instruction to uplink transmitter switch between a carrier pair including a first carrier (Cl) and a second carrier (C2), where C2 is assigned two transmitter chains.

[0079] At 834, method 830 involves receiving a second instruction to perform SRS-CS to transmit an SRS resource set in a third carrier (C3), where the third carrier is a downlink carrier.

[0080] At 836, method 830 involves while in a starting uplink transmitter switching state, determining that a scheduled uplink transmission on the first carrier (Cl) overlaps with a scheduled SRS transmission on the third carrier (C3).

[0081] At 838, method 830 involves responsively selecting at least one of the scheduled uplink transmission on the first carrier (Cl) or the scheduled SRS transmission on the third carrier (C3) for transmission.

[0082] Turning to FIG. 8E, at 842, method 840 involves receiving a first instruction that configures a UE (such as the UE 102 of FIG. 1) to perform uplink Tx switching between a first carrier (Cl) and a second carrier (C2) that is shared by a first Tx chain and a second Tx chain.

[0083] At 844, method 840 involves receiving a second instruction that configures the UE to perform SRS-CS on a third carrier (C3).

[0084] At 846, method 840 involves switching at least one of the first Tx chain or the second Tx chain to the third carrier (C3) in accordance with the second instruction.

[0085] At 848, method 840 involves transmitting at least one SRS via an SRS resource set on the third carrier (C3) after a switching gap has elapsed.

[0086] FIG. 9 illustrates an example UE 900, according to some implementations. The UE 900 may be similar to and substantially interchangeable with UE 102 of FIG. 1.

[0087] The UE 900 may be any mobile or non-mobile computing device, such as, for example, mobile phones, computers, tablets, industrial wireless sensors (for example, microphones,Attorney Docket No. 56990-0035W01 / P68414WO1 pressure sensors, thermometers, motion sensors, accelerometers, inventory sensors, electric voltage / current meters, etc.), video devices (for example, cameras, video cameras, etc.), wearable devices (for example, a smart watch), relaxed-IoT devices.

[0088] The UE 900 may include processors 902, RF interface circuitry 904, memory / storage 906, user interface 908, sensors 910, driver circuitry 912, power management integrated circuit (PMIC) 914, one or more antenna(s) 916, and battery 918. The components of the UE 900 may be implemented as integrated circuits (ICs), portions thereof, discrete electronic devices, or other modules, logic, hardware, software, firmware, or a combination thereof. The block diagram of FIG. 9 is intended to show a high-level view of some of the components of the UE 900. However, some of the components shown may be omitted, additional components may be present, and different arrangement of the components shown may occur in other implementations.

[0089] The components of the UE 900 may be coupled with various other components over one or more interconnects 920, which may represent any type of interface, input / output, bus (local, system, or expansion), transmission line, trace, optical connection, etc., that allows various circuit components (on common or different chips or chipsets) to interact with one another.

[0090] The processors 902 may include processor circuitry such as, for example, baseband processor circuitry (BB) 922A, central processor unit circuitry (CPU) 922B, and graphics processor unit circuitry (GPU) 922C. The processors 902 may include any type of circuitry or processor circuitry that executes or otherwise operates computer-executable instructions, such as program code, software modules, or functional processes from memory / storage 906 to cause the UE 900 to perform operations as described herein.

[0091] In some implementations, the baseband processor circuitry 922A may access a communication protocol stack 924 in the memory / storage 906 to communicate over a 3 GPP compatible network. In general, the baseband processor circuitry 922A may access the communication protocol stack to: perform user plane functions at a physical (PHY) layer, medium access control (MAC) layer, radio link control (RLC) layer, packet data convergence protocol (PDCP) layer, service data adaptation protocol (SDAP) layer, and PDU layer; and perform control plane functions at a PHY layer, MAC layer, RLC layer, PDCP layer, RRC layer, and a non-access stratum layer. In some implementations, the PHY layer operations may additionally / altematively be performed by the components of the RF interface circuitry 904.Attorney Docket No. 56990-0035W01 / P68414WO1The baseband processor circuitry 922A may generate or process baseband signals or waveforms that carry information in 3 GPP-compatible networks. In some implementations, the waveforms for NR may be based cyclic prefix orthogonal frequency division multiplexing (OFDM) “CP-OFDM” in the uplink or downlink, and discrete Fourier transform spread OFDM “DFT-S-OFDM” in the uplink.

[0092] The memory / storage 906 may include one or more non -transitory, computer-readable media that includes instructions (for example, communication protocol stack 924) that may be executed by one or more of the processors 902 to cause the UE 900 to perform various operations described herein. The memory / storage 906 include any type of volatile or nonvolatile memory that may be distributed throughout the UE 900. In some implementations, some of the memory / storage 906 may be located on the processors 902 themselves (for example, LI and L2 cache), while other memory / storage 906 is external to the processors 902 but accessible thereto via a memory interface. The memory / storage 906 may include any suitable volatile or non-volatile memory such as, but not limited to, dynamic random access memory (DRAM), static random access memory (SRAM), erasable programmable read only memory (EPROM), electrically erasable programmable read only memory (EEPROM), Flash memory, solid-state memory, or any other type of memory device technology.

[0093] The RF interface circuitry 904 may include transceiver circuitry and radio frequency front module (RFEM) that allows the UE 900 to communicate with other devices over a radio access network. The RF interface circuitry 904 may include various elements arranged in transmit or receive paths. These elements may include, for example, switches, mixers, amplifiers, filters, synthesizer circuitry, control circuitry, etc.

[0094] In the receive path, the RFEM may receive a radiated signal from an air interface via antenna(s) 916 and proceed to filter and amplify (with a low-noise amplifier) the signal. The signal may be provided to a receiver of the transceiver that downconverts the RF signal into a baseband signal that is provided to the baseband processor of the processors 902.

[0095] In the transmit path, the transmitter of the transceiver up-converts the baseband signal received from the baseband processor and provides the RF signal to the RFEM. The RFEM may amplify the RF signal through a power amplifier prior to the signal being radiated across the air interface via the antenna(s) 916. In various implementations, the RF interface circuitry 904 may be configured to transmit / receive signals in a manner compatible with NR access technologies.Attorney Docket No. 56990-0035W01 / P68414WO1

[0096] The antenna(s) 916 may include one or more antenna elements to convert electrical signals into radio waves to travel through the air and to convert received radio waves into electrical signals. The antenna elements may be arranged into one or more antenna panels. The antenna(s) 916 may have antenna panels that are omnidirectional, directional, or a combination thereof to enable beamforming and multiple input, multiple output communications. The antenna(s) 916 may include microstrip antennas, printed antennas fabricated on the surface of one or more printed circuit boards, patch antennas, phased array antennas, etc. The antenna(s) 916 may have one or more panels designed for specific frequency bands including bands in FR1 or FR2.

[0097] The user interface 908 includes various input / output (VO) devices designed to enable user interaction with the UE 900. The user interface 908 includes input device circuitry and output device circuitry. Input device circuitry includes any physical or virtual means for accepting an input including, inter alia, one or more physical or virtual buttons (for example, a reset button), a physical keyboard, keypad, mouse, touchpad, touchscreen, microphones, scanner, headset, or the like. The output device circuitry includes any physical or virtual means for showing information or otherwise conveying information, such as sensor readings, actuator position(s), or other like information. Output device circuitry may include any number or combinations of audio or visual display, including, inter alia, one or more simple visual outputs / indicators (for example, binary status indicators such as light emitting diodes “LEDs” and multi -character visual outputs), or more complex outputs such as display devices or touchscreens (for example, liquid crystal displays “LCDs,” LED displays, quantum dot displays, projectors, etc.), with the output of characters, graphics, multimedia objects, and the like being generated or produced from the operation of the UE 900.

[0098] The sensors 910 may include devices, modules, or subsystems whose purpose is to detect events or changes in its environment and send the information (sensor data) about the detected events to some other device, module, subsystem, etc. Examples of such sensors include, inter alia, inertia measurement units including accelerometers, gyroscopes, or magnetometers; microelectromechanical systems or nanoelectromechanical systems including 3-axis accelerometers, 3-axis gyroscopes, or magnetometers; level sensors; temperature sensors (for example, thermistors); pressure sensors; image capture devices (for example, cameras or lensless apertures); light detection and ranging sensors; proximity sensors (for example, infrared radiation detector and the like); depth sensors; ambient light sensors; ultrasonic transceivers; microphones or other like audio capture devices; etc.Attorney Docket No. 56990-0035W01 / P68414WO1

[0099] The driver circuitry 912 may include software and hardware elements that operate to control particular devices that are embedded in the UE 900, attached to the UE 900, or otherwise communicatively coupled with the UE 900. The driver circuitry 912 may include individual drivers allowing other components to interact with or control various input / output (EO) devices that may be present within, or connected to, the UE 900. For example, driver circuitry 912 may include a display driver to control and allow access to a display device, a touchscreen driver to control and allow access to a touchscreen interface, sensor drivers to obtain sensor readings of sensors 910 and control and allow access to sensors 910, drivers to obtain actuator positions of electro-mechanic components or control and allow access to the electro-mechanic components, a camera driver to control and allow access to an embedded image capture device, audio drivers to control and allow access to one or more audio devices.

[0100] The PMIC 914 may manage power provided to various components of the UE 900. In particular, with respect to the processors 902, the PMIC 914 may control power-source selection, voltage scaling, battery charging, or DC-to-DC conversion.

[0101] In some implementations, the PMIC 914 may control, or otherwise be part of, various power saving mechanisms of the UE 900. A battery 918 may power the UE 900, although in some examples the UE 900 may be mounted deployed in a fixed location, and may have a power supply coupled to an electrical grid. The battery 918 may be a lithium ion battery, a metal-air battery, such as a zinc-air battery, an aluminum-air battery, a lithium-air battery, and the like. In some implementations, such as in vehicle-based applications, the battery 918 may be a typical lead-acid automotive battery.

[0102] FIG. 10 illustrates an example access node 1000 (e.g., abase station or gNB), according to some implementations. The access node 1000 may be similar to and substantially interchangeable with base station 104. The access node 1000 may include processors 1002, RF interface circuitry 1004, core network (CN) interface circuitry 1006, memory / storage circuitry 1008, and one or more antenna(s) 1010.

[0103] The components of the access node 1000 may be coupled with various other components over one or more interconnects 1012. The processors 1002, RF interface circuitry 1004, memory / storage circuitry 1008 (including communication protocol stack 1014), antenna(s) 1010, and interconnects 1012 may be similar to like-named elements shown and described with respect to FIG. 9. For example, the processors 1002 may include processorAttorney Docket No. 56990-0035W01 / P68414WO1 circuitry such as, for example, baseband processor circuitry (BB) 1016A, central processor unit circuitry (CPU) 1016B, and graphics processor unit circuitry (GPU) 1016C.

[0104] The CN interface circuitry 1006 may provide connectivity to a core network, for example, a 5th Generation Core network (5GC) using a 5GC -compatible network interface protocol such as carrier Ethernet protocols, or some other suitable protocol. Network connectivity may be provided to / from the access node 1000 via a fiber optic or wireless backhaul. The CN interface circuitry 1006 may include one or more dedicated processors or FPGAs to communicate using one or more of the aforementioned protocols. In some implementations, the CN interface circuitry 1006 may include multiple controllers to provide connectivity to other networks using the same or different protocols.

[0105] As used herein, the terms “access node,” “access point,” or the like may describe equipment that provides the radio baseband functions for data and / or voice connectivity between a network and one or more users. These access nodes can be referred to as BS, gNBs, RAN nodes, eNBs, NodeBs, RSUs, TRxPs or TRPs, and so forth, and can include ground stations (e.g., terrestrial access points) or satellite stations providing coverage within a geographic area (e.g., a cell). As used herein, the term “NG RAN node” or the like may refer to an access node 1000 that operates in an NR or 5G system (for example, a gNB), and the term “E-UTRAN node” or the like may refer to an access node 1000 that operates in an LTE or 4G system (e.g., an eNB). According to various implementations, the access node 1000 may be implemented as one or more of a dedicated physical device such as a macrocell base station, and / or a low power (LP) base station for providing femtocells, picocells or other like cells having smaller coverage areas, smaller user capacity, or higher bandwidth compared to macrocells.

[0106] In some implementations, all or parts of the access node 1000 may be implemented as one or more software entities running on server computers as part of a virtual network, which may be referred to as a CRAN and / or a virtual baseband unit pool (vBBUP). In V2X scenarios, the access node 1000 may be or act as a “Road Side Unit.” The term “Road Side Unit” or “RSU” may refer to any transportation infrastructure entity used for V2X communications. An RSU may be implemented in or by a suitable RAN node or a stationary (or relatively stationary) UE, where an RSU implemented in or by a UE may be referred to as a “UE-type RSU,” an RSU implemented in or by an eNB may be referred to as an “eNB-type RSU,” an RSU implemented in or by a gNB may be referred to as a “gNB-type RSU,” and the like.Attorney Docket No. 56990-0035W01 / P68414WO1

[0107] Various components may be described as performing a task or tasks, for convenience in the description. Such descriptions should be interpreted as including the phrase “configured to.” Reciting a component that is configured to perform one or more tasks is expressly intended not to invoke 35 U.S.C. § 112(f) interpretation for that component.

[0108] For one or more embodiments, at least one of the components set forth in one or more of the preceding figures may be configured to perform one or more operations, techniques, processes, or methods as set forth in the example section below. For example, the baseband circuitry as described above in connection with one or more of the preceding figures may be configured to operate in accordance with one or more of the examples set forth below. For another example, circuitry associated with a UE, base station, network element, etc., as described above in connection with one or more of the preceding figures may be configured to operate in accordance with one or more of the examples set forth below in the example section.

[0109] In the following sections, further exemplary embodiments are provided.

[0110] Example 1 includes a UE configured to perform operations including: receiving a first instruction to uplink transmitter switch between a carrier pair including a first carrier (Cl) and a second carrier (C2), where C2 is assigned two transmitter chains; receiving a second instruction to perform SRS-CS to transmit an SRS resource set in a third carrier (C3), where the third carrier is a downlink carrier; while in a starting uplink transmitter switching state, transmitting an uplink transmission on the first carrier (Cl); switching the two transmitter chains to the third carrier (C3); and after a switching gap has elapsed, transmitting an SRS resource set on the third carrier (C3).

[0111] Example 2 includes the UE of Example 1, where switching the two transmitter chains to the third carrier includes: switching a first transmitter chain from the first carrier (Cl) to the second carrier (C2); and switching the first transmitter chain and a second transmitter chain from the second carrier (C2) to the third carrier (C3).

[0112] Example 3 includes the UE of Example 2, where the switching gap includes a combination of an uplink transmitter switching period and an SRS switching time.

[0113] Example 4 includes the UE of example 1, where switching the two transmitter chains to the third carrier includes: directly switching: (i) a first transmitter chain from the first carrier (Cl) to the third carrier (C2), and (ii) a second transmitter chain from the second carrier (C2) to the third carrier (C3).Attorney Docket No. 56990-0035W01 / P68414WO1

[0114] Example 5 includes the UE of Example 2, where the switching gap includes an SRS switching time.

[0115] Example 6 includes the UE of Example 1, the operations further including: after transmitting the SRS resource set, switching the transmitter chain back to the source carrier, where a tuning time to switch the transmitter chain back to the source carrier comprises an SRS switching time.

[0116] Example 7 includes the UE of Example 1, the operations further including: after transmitting the SRS resource set, switching the transmitter chain back to the starting uplink transmitter switching state, where a tuning time to switch the transmitter chain back to the source carrier includes: (i) a combination of an uplink transmitter switching period and an SRS switching time, or (ii) the SRS switching time.

[0117] Example 8 includes the UE of Example 1, where the uplink transmission is a first scheduled uplink transmission, where a second scheduled uplink transmission on the second carrier (C2) overlaps with the SRS resource set on the third carrier (C3), and the operations further including: selecting one of the first scheduled uplink transmission and the second scheduled uplink transmission for transmission; and applying SRS-CS prioritization to: (i) the selected one of the first scheduled uplink transmission and the second scheduled uplink transmission, and (ii) the SRS resource set on the third carrier (C3).

[0118] Example 9 includes a UE configured to perform operations including: receiving a first instruction to uplink transmitter switch between a carrier pair including a first carrier (Cl) and a second carrier (C2), where C2 is assigned two transmitter chains; receiving a second instruction to perform SRS-CS to transmit a two-antenna port (2-AP) SRS transmission on a third carrier (C3), where the third carrier (C3) is a downlink carrier; determining that a scheduled uplink transmission on the first carrier (Cl) or the second carrier (C2) overlaps with the 2-AP SRS transmission on the third carrier (C3); and responsively dropping one of the uplink transmission and the 2-AP SRS transmission.

[0119] Example 10 includes the UE of Example 9, where determining that the scheduled uplink transmission overlaps with the 2-AP SRS transmission includes: determining that the scheduled uplink transmission overlaps with an SRS transmission timeline, the SRS transmission timeline including: an uplink transmitter switching period for switching the two transmitter chains to the third carrier (C3); a number of symbols for the 2-AP SRS transmission; an SRS antenna switching gap between two SRS resources within the 2-AP SRS transmission; and an SRSAttorney Docket No. 56990-0035W01 / P68414WO1 switching time for switching the two transmitter chains to at least one of the first carrier (Cl) or the second carrier (C2).

[0120] Example 11 includes the UE of Example 9, where responsively dropping one of the uplink transmission and the 2-AP SRS transmission includes: prioritizing the uplink transmission and dropping the 2-AP SRS transmission; or prioritizing 2-AP SRS transmission and dropping the uplink transmission.

[0121] Example 12 includes the UE of Example 9, where responsively dropping one of the uplink transmission and the 2-AP SRS transmission includes: comparing respective priorities of the uplink transmission and the 2-AP SRS transmission; prioritizing the one of the uplink transmission and the 2-AP SRS transmission with a higher priority; and dropping the other one of the uplink transmission and the 2-AP SRS transmission with a lower priority.

[0122] Example 13 includes the UE of Example 9, where responsively dropping one of the uplink transmission and the 2-AP SRS transmission includes dropping the uplink transmission, and where dropping the uplink transmission includes: determining that a cancellation DCI is received at least by To - TprOc,2, where To is an earliest symbol between 2-AP SRS transmission and the uplink transmission, and TprOc,2 is an uplink preparation procedure time.

[0123] Example 14 includes the UE of Example 13, where the cancellation DCI is a DCI 2 3 scheduling the 2-AP SRS transmission.

[0124] Example 15 includes the UE of Example 9, where responsively dropping one of the uplink transmission and the 2-AP SRS transmission includes dropping the 2-AP SRS transmission, and where dropping the 2-AP SRS transmission includes: determining that a cancellation DCI is received at least by To - TprOc,2, where To is an earliest symbol between 2- AP SRS transmission and the uplink transmission, and TprOc,2 is.

[0125] Example 16 includes the UE of Example 15, where the cancellation DCI is a DCI 1 1 scheduling the uplink transmission.

[0126] Example 17 includes a UE configured to perform operations including: transmitting a capability indicating that the UE supports a parallel SRS-CS transmission on a first carrier and an uplink transmission on a second carrier; and transmitting in parallel the SRS-CS transmission on the first carrier and the uplink transmission on the second carrier.Attorney Docket No. 56990-0035W01 / P68414WO1

[0127] Example 18 includes the UE of Example 17, where the uplink transmission is an SRS- Antenna Switching (SRS-AS) transmission on the second carrier, and where the SRS-CS and the SRS-AS are aligned in time.

[0128] Example 19 includes the UE of Example 18, where the SRS-CS and the SRS-AS use the same antenna port configuration.

[0129] Example 20 includes the UE of Example 17, where the SRS-CS transmission is a first SRS-CS transmission, and where the uplink transmission is a second SRS-CS transmission, and where the first SRS-CS and the second SRS-CS are aligned in time.

[0130] Example 21 includes a UE configured to perform operations including: receiving a first instruction to uplink transmitter switch between a carrier pair including a first carrier (Cl) and a second carrier (C2), where C2 is assigned two transmitter chains; receiving a second instruction to perform SRS-CS to transmit an SRS resource set in a third carrier (C3), where the third carrier is a downlink carrier; while in a starting uplink transmitter switching state, determining that a scheduled uplink transmission on the first carrier (Cl) overlaps with a scheduled SRS transmission on the third carrier (C3); and responsively selecting at least one of the scheduled uplink transmission on the first carrier (Cl) or the scheduled SRS transmission on the third carrier (C3) for transmission.

[0131] Example 22 includes the UE of Example 21, where responsively selecting at least one of the scheduled uplink transmission on the first carrier (Cl) or the scheduled SRS transmission on the third carrier (C3) for transmission includes: determining that the UE is capable of parallel transmission; and selecting both the scheduled uplink transmission on the first carrier (Cl) and the scheduled SRS transmission on the third carrier (C3) for simultaneous transmission.

[0132] Example 23 includes the UE of Example 21, where responsively selecting at least one of the scheduled uplink transmission on the first carrier (Cl) or the scheduled SRS transmission on the third carrier (C3) for transmission includes: determining that the UE is not capable of parallel transmission; and selecting one of the scheduled uplink transmission on the first carrier (Cl) and the scheduled SRS transmission on the third carrier (C3) for transmission.

[0133] Example 24 includes the UE of Example 23, where selecting one of the scheduled uplink transmission on the first carrier (Cl) and the scheduled SRS transmission on the third carrier (C3) for transmission is based on prioritization rules.Attorney Docket No. 56990-0035W01 / P68414WO1

[0134] Example 25 may include one or more non-transitory computer-readable media including instructions to cause an electronic device, upon execution of the instructions by one or more processors of the electronic device, to perform one or more elements of a method described in or related to any of examples 1-24, or any other method or process described herein.

[0135] Example 26 may include an apparatus including logic, modules, and / or circuitry (e.g., processing circuitry) to perform one or more elements of a method described in or related to any of examples 1-24, or any other method or process described herein.

[0136] Example 27 may include a method, technique, or process as described in or related to any of examples 1-24, or portions or parts thereof.

[0137] Example 28 may include an apparatus including: one or more processors and one or more computer-readable media including instructions that, when executed by the one or more processors, cause the one or more processors to perform the method, techniques, or process as described in or related to any of examples 1-24, or portions thereof.

[0138] Example 29 may include a signal as described in or related to any of examples 1-24, or portions or parts thereof.

[0139] Example 30 may include a computer program including instructions, where execution of the program by a processing element is to cause the processing element to carry out the method, techniques, or process as described in or related to any of examples 1- 24, or portions thereof. The operations or actions performed by the instructions executed by the processing element can include the methods of any one of examples 1-24.

[0140] Example 31 may include a method of communicating in a wireless network as shown and described herein.

[0141] Example 32 may include a system for providing wireless communication as shown and described herein. The operations or actions performed by the system can include the methods of any one of examples 1-24.

[0142] Example 33 may include a device for providing wireless communication as shown and described herein. The operations or actions performed by the device can include the methods of any one of examples 1-24.Attorney Docket No. 56990-0035W01 / P68414WO1

[0143] Example 34 is a method including: receiving a first instruction that configures a UE to perform uplink transmit switching between a first carrier and a second carrier that is shared by a first transmit chain and a second transmit chain; receiving a second instruction that configures the UE to perform SRS-CS on a third carrier; switching at least one of the first transmit chain or the second transmit chain to the third carrier in accordance with the second instruction; and after a switching gap has elapsed, transmitting at least one SRS via an SRS resource set on the third carrier.

[0144] Example 35 includes the method of example 34, further including receiving a third parameter that configures an SRS switching time for NR, where the switching gap includes the SRS switching time.

[0145] Example 36 includes the method of any of examples 34-35, where the second instruction configures the UE to perform SRS-CS from the second carrier to the third carrier.

[0146] Example 37 includes the method of any of examples 34-36, where a duration of the switching gap is based on a capability of the UE.

[0147] Example 38 includes the method of any of examples 34-37, where a duration of the switching gap depends on whether all transmit chains of the UE are available on the second carrier.

[0148] Example 39 includes the method of any of examples 34-38, further including transmitting UE capability information to indicate that SRS-CS on the third carrier impacts the first carrier sharing transmit chains with the second carrier.

[0149] Example 40 includes the method of any of examples 34-39, further including transmitting a second uplink message on the first carrier after a second switching gap that begins after transmission of the at least one SRS is complete.

[0150] Example 41 includes the method of any of examples 34-40, where the first carrier includes a first uplink CC, the second carrier includes a second uplink CC, and the third carrier includes a downlink CC.

[0151] Example 42 includes the method of any of examples 34-41, further including switching at least one of the first transmit chain or the second transmit chain back to the second transmit chain after transmission of the at least one SRS is complete.Attorney Docket No. 56990-0035W01 / P68414WO1

[0152] Example 43 includes the method of any of examples 34-42, where switching at least one of the first transmit chain or the second transmit chain to the third carrier includes: switching the first transmit chain from the first carrier to the second carrier; and switching the first transmit chain and the second transmit chain from the second carrier to the third carrier.

[0153] Example 44 includes the method of any of examples 34-43, further including determining that an uplink transmission scheduled on the first carrier overlaps with an SRS transmission scheduled on the third carrier.

[0154] Example 45 includes the method of example 44, further including selecting at least one of the uplink transmission scheduled on the first carrier or the SRS transmission scheduled on the third carrier for transmission.

[0155] Example 46 includes the method of example 45, where selecting at least one of the uplink transmission or the SRS transmission includes: determining that the UE is capable of simultaneous transmission; and selecting both the uplink transmission scheduled on the first carrier and the SRS transmission scheduled on the third carrier for simultaneous transmission.

[0156] Example 47 includes the method of any of examples 45-46, where selecting at least one of the uplink transmission or the SRS transmission includes: determining that the UE is not capable of simultaneous transmission; and selecting either the uplink transmission scheduled on the first carrier or the SRS transmission scheduled on the third carrier for transmission.

[0157] Example 48 includes the method of any of examples 45-47, where selecting at least one of the uplink transmission or the SRS transmission is based on a set of prioritization rules.

[0158] Example 49 includes the method of any of examples 34-48, further including transmitting UE capability information to indicate whether the UE is capable of simultaneously transmitting an uplink message on the first carrier and an SRS on the second carrier or the third carrier.

[0159] Example 50 includes one or more processors configured to, when executing instructions stored in a memory, perform the method of any of examples 34-49.

[0160] Example 51 is a UE configured to perform the method of any of examples 34-49.

[0161] Example 52 is a non-transitory computer-readable medium storing instructions that, when executed by one or more processors, cause the one or more processors to perform the method of any of examples 34-49.Attorney Docket No. 56990-0035W01 / P68414WO1

[0162] The previously-described examples 1-52 are implementable using a computer- implemented method; a non-transitory, computer-readable medium storing computer-readable instructions to perform the computer-implemented method; and a computer system including a computer memory interoperably coupled with a hardware processor configured to perform the computer-implemented method or the instructions stored on the non-transitory, computer- readable medium.

[0163] Any of the above-described examples may be combined with any other example (or combination of examples), unless explicitly stated otherwise. The foregoing description of one or more implementations provides illustration and description, but is not intended to be exhaustive or to limit the scope of embodiments to the precise form disclosed. Modifications and variations are possible in light of the above teachings or may be acquired from practice of various embodiments.

[0164] Although the embodiments above have been described in considerable detail, numerous variations and modifications will become apparent to those skilled in the art once the above disclosure is fully appreciated. It is intended that the following claims be interpreted to embrace all such variations and modifications.

[0165] It is well understood that the use of personally identifiable information should follow privacy policies and practices that are generally recognized as meeting or exceeding industry or governmental requirements for maintaining the privacy of users. In particular, personally identifiable information data should be managed and handled so as to minimize risks of unintentional or unauthorized access or use, and the nature of authorized use should be clearly indicated to users.

Claims

Attorney Docket No. 56990-0035W01 / P68414WO1CLAIMSWe Claim:

1. A method comprising: receiving a first instruction that configures a user equipment (UE) to perform uplink transmit switching between a first carrier and a second carrier that is shared by a first transmit chain and a second transmit chain; receiving a second instruction that configures the UE to perform sounding reference signal (SRS)-carrier switching (CS) on a third carrier; switching at least one of the first transmit chain or the second transmit chain to the third carrier in accordance with the second instruction; and after a switching gap has elapsed, transmitting at least one SRS via an SRS resource set on the third carrier.

2. The method of claim 1, further comprising receiving a third parameter that configures an SRS switching time for New Radio (NR), wherein the switching gap comprises the SRS switching time.

3. The method of claim 1, wherein the second instruction configures the UE to perform SRS-CS from the second carrier to the third carrier.

4. The method of claim 1, wherein a duration of the switching gap is based on a capability of the UE.

5. The method of claim 1, wherein a duration of the switching gap depends on whether all transmit chains of the UE are available on the second carrier.

6. The method of claim 1, further comprising transmitting UE capability information to indicate that SRS-CS on the third carrier impacts the first carrier sharing transmit chains with the second carrier.Attorney Docket No. 56990-0035W01 / P68414WO17. The method of claim 1, further comprising transmitting an uplink message on the first carrier after a second switching gap that begins after transmission of the at least one SRS is complete.

8. The method of claim 1, wherein the first carrier comprises a first uplink component carrier (CC), the second carrier comprises a second uplink CC, and the third carrier comprises a downlink CC.

9. The method of claim 1, further comprising switching at least one of the first transmit chain or the second transmit chain back to the second transmit chain after transmission of the at least one SRS is complete.

10. The method of claim 1, wherein switching at least one of the first transmit chain or the second transmit chain to the third carrier comprises: switching the first transmit chain from the first carrier to the second carrier; and switching the first transmit chain and the second transmit chain from the second carrier to the third carrier.

11. The method of claim 1, further comprising determining that an uplink transmission scheduled on the first carrier overlaps with an SRS transmission scheduled on the third carrier.

12. The method of claim 11, further comprising selecting at least one of the uplink transmission scheduled on the first carrier or the SRS transmission scheduled on the third carrier for transmission.

13. The method of claim 12, wherein selecting at least one of the uplink transmission or the SRS transmission comprises: determining that the UE is capable of simultaneous transmission; and selecting both the uplink transmission scheduled on the first carrier and the SRS transmission scheduled on the third carrier for simultaneous transmission.

14. The method of claim 12, wherein selecting at least one of the uplink transmission or the SRS transmission comprises: determining that the UE is not capable of simultaneous transmission; andAttorney Docket No. 56990-0035W01 / P68414WO1 selecting either the uplink transmission scheduled on the first carrier or the SRS transmission scheduled on the third carrier for transmission.

15. The method of claim 12, wherein selecting at least one of the uplink transmission or the SRS transmission is based on a set of prioritization rules.

16. The method of claim 1, further comprising transmitting UE capability information to indicate whether the UE is capable of simultaneously transmitting an uplink message on the first carrier and an SRS on the second carrier or the third carrier.

17. One or more processors configured to, when executing instructions stored in a memory, perform the method of any of claims 1-16.

18. AUE configured to perform the method of any of claims 1-16.

19. A non-transitory computer-readable medium storing instructions that, when executed by one or more processors, cause the one or more processors to perform the method of any of claims 1-16.

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