Managing Uplink Transmit Chain Switching

Abstract

A method in a user equipment (UE) having a first transmitter and a second transmitter, the method including: transmitting a first uplink transmission using the first transmitter switched to a first frequency band and using the second transmitter switched to a second frequency band; receiving, from a radio access network (RAN), an uplink switching configuration for a second uplink transmission using the first transmitter, the uplink switching configuration including (i) a first parameter indicating whether to switch the second transmitter away from the second frequency band and (ii) a second parameter indicating to which frequency band the UE should switch the second transmitter; and transmitting the second uplink transmission in accordance with the uplink switching configuration.

Description

[Technical Field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims priority to and claims the benefit of the filing date of Provisional U.S. Patent Application No. 63 / 377,694, entitled "MANAGING UPLINK TRANSMISSION CHAIN ​​SWITCHING," filed September 29, 2022. The entire contents of the provisional application are expressly incorporated herein by reference.

[0002] The present disclosure relates to wireless communications, and more particularly to supporting uplink (UL) transmitter switching between multiple carrier frequencies or frequency bands. [Background technology]

[0003] This background discussion is provided for the purpose of outlining the context for the present disclosure. The work of the inventors identified herein, to the extent described in this background section, and aspects of the present specification that may not qualify as prior art at the time of filing, are not admitted expressly or impliedly as prior art to the present disclosure.

[0004] For some user equipment (UE), if the UE has two transmitters and is configured with a physical uplink (UL) shared channel (PUSCH) for component carriers in two bands, the UE configures one transmitter (also called a Tx or antenna) for the component carrier(s) in one band and the other transmitter for the component carrier(s) in the other band. However, in some scenarios, the base station schedules transmissions in only one band. Thus, one transmitter remains idle. To better utilize the idle transmitter, UL switching technology supports scenarios such as inter-band evolved universal terrestrial radio access network (E-UTRAN) new radio (NR) dual connectivity (DC) (EN-DC) without simultaneous uplink (SUL), inter-band UL carrier aggregation (CA), and standalone SUL. Regarding Tx states, two cases, Case 1 and Case 2, are supported for some UL switching. Case 1 indicates a Tx state in which the UE configures two transmitters (1T-1T) for two component carriers, respectively. In Case 2, the UE configures two transmitters (0T-2T) for the second carrier.

[0005] In some scenarios, each Tx state supports transmission with different antenna port allocations without antenna switching. In some such examples, the Case 1 (1T-1T) Tx state supports two simultaneous single-port transmissions on two component carriers (1P-1P), a single-port transmission on component carrier 1 (1P-0P), and a single-port transmission on component carrier 2 (0P-1P). Meanwhile, the Case 2 (0T-2T) Tx state supports a single-port transmission on component carrier 2 (0P-1P) and a two-port transmission (UL-MIMO) on component carrier 2 (0P-2P). In some scenarios, the base station triggers the UE to switch Tx states by dynamic scheduling (i.e., using downlink control information (DCI)) and semi-static UL scheduling (i.e., radio resource control (RRC) configured grants). If the UE has a Tx state of case 2 and is scheduled with single port transmission (1P-0P) on component carrier 1, since the UE currently does not have a Tx configured on component carrier 1, the UE will switch one Tx to component carrier 1 to perform such transmission.

[0006] In a further scenario, UL switching is enhanced to support two-port transmission on component carrier 1 (Case 3). The newly added Case 3 creates an ambiguous issue when the UE performs UL switching. In one scenario, the last transmission the UE performed on carrier 2 was a two-port transmission (i.e., 0P-2P in Case 2), and the UE receives DCI from the gNB scheduling a one-port transmission on carrier 1 (i.e., 1P-0P in Case 1 or Case 3). In such a scenario, the UE performs UL switching (e.g., antenna port switching, UL transmit chain switching, or UL transmit (Tx) switching) to transmit a one-port transmission. During UL switching, the UE switches one of its two antenna ports from carrier 2 to carrier 1 and transmits a one-port transmission using the switched antenna port. However, the UE must decide whether to change its Tx state (i.e., whether to switch the other antenna port from carrier 2 to carrier 1 (e.g., Case 3 or Case 1)). The gNB also needs to know the UE's Tx state to schedule the next uplink transmission. To resolve the ambiguity, a new radio resource control (RRC) parameter (e.g., uplinkTxSwitching-DalUL-TxState-r17) is introduced, which can be set to the value oneT or twoT. In some such scenarios, the gNB sends the UE uplinkTxSwitching-DalUL-TxState-r17 set to oneT to configure the UE not to switch the other antenna port in the above scenario. Thus, the UE does not switch the other antenna port after transmitting one port transmission according to the oneT value. Alternatively, the gNB sends the UE uplinkTxSwitching-DalUL-TxState-r17 set to twoT to configure the UE to switch the other antenna port from carrier 2 to carrier 1 in the above scenario. Thus, the UE switches the other antenna port from carrier 2 to carrier 1 after transmitting one port transmission according to the twoT value. Summary of the Invention [Means for solving the problem]

[0007] An exemplary embodiment of the techniques of the present disclosure is a method in a user equipment (UE) having a first transmitter and a second transmitter, the method including: transmitting a first uplink transmission using the first transmitter switched to a first frequency band and using the second transmitter switched to a second frequency band; receiving, from a radio access network (RAN), an uplink switching configuration for a second uplink transmission using the first transmitter, the uplink switching configuration including (i) a first parameter indicating whether to switch the second transmitter away from the second frequency band and (ii) a second parameter indicating to which frequency band the UE should switch the second transmitter; and transmitting the second uplink transmission in accordance with the uplink switching configuration.

[0008] Another example embodiment of the present technology is a method in a Radio Access Network (RAN) node, the method including: receiving a first uplink transmission from a user equipment (UE) having a first transmitter and a second transmitter over a first frequency band and a second frequency band; and transmitting an uplink switching configuration for a second uplink transmission over a third frequency band to the UE, the uplink switching configuration including (i) a first parameter indicating whether to switch the second transmitter away from the second frequency band, and (ii) a second parameter indicating to which frequency band the UE should switch the second transmitter. [Brief explanation of the drawings]

[0009] [Figure 1A] FIG. 1 is a block diagram of an example wireless communication system in which the RAN and / or UE implement the techniques of this disclosure for managing Tx states for UL switching. [Figure 1B]1B is a block diagram of an exemplary base station including a central unit (CU) and a distributed unit (DU) capable of operating in the system of FIG. 1A. [Figure 2] 1B is a block diagram of an example protocol stack according to which the UE of FIG. 1A communicates with a base station. [Figure 3] FIG. 1 is a messaging diagram of an embodiment of UL switching. [Figure 4A] FIG. 10 is a messaging diagram for delivering UL switching configuration under DC with a specific cell group configuration path. [Figure 4B] 4B is a messaging diagram similar to FIG. 4A, in which the scenario is performed using a different cell group configuration path. [Figure 5] 5 is a flow diagram of an example method 500 illustrating general UE procedures in UL switching. [Figure 6] 6 is a flow diagram of an example method 600 in which a UE determines a Tx state according to a cell index configured by a base station when a non-unique UL switching case occurs. [Figure 7A] 7 is a flow diagram of an example method 700A in which a UE determines a Tx state according to cell / band priorities configured by a base station when a non-unique UL switching case occurs. [Figure 7B] 7 is a flow diagram of an example method 700B in which a UE determines a Tx state according to a cell index configured by a base station when a non-unique UL switching case occurs. [Figure 8] 8 is a flow diagram of an example method 800 in which, when a non-unique UL switching case occurs, a UE determines a Tx state according to a Tx state indication for each non-unique UL switching case configured by a base station. [Figure 9A] 9 is a flow diagram of an example method 900A in which a UE determines a Tx state according to a cell / band indicator carried by a scheduling DCI format. [Figure 9B]9 is a flow diagram of an example method 900B similar to that of method 900A, but in which the UE determines whether to update the Tx state based on the last scheduling DCI according to whether the transmission is scheduled by the DCI. [Figure 10A] 10 is a flow diagram of an example method 1000A in which a UE determines a Tx state according to a single UL switching Tx state configuration. [Figure 10B] 10 is an example flow diagram of a method 1000B similar to that of method 1000B, but in which the UE determines the Tx state according to multiple UL switching Tx state configurations. [Figure 10C] 10 is a flow diagram of an example method 1000C for determining whether to update a current transmission configuration based on whether a determined Tx state is the same as a current Tx state. [Figure 11A] 11 is a flow diagram of an example method 1100A in which a base station transmits an indication of a UL switching TX state of an unscheduled Tx. [Figure 11B] 11 is a flow diagram of an example method 1100B similar to that of method 1100A, but in which the base station transmits the UL Tx switching priority of the cell. [Figure 11C] 11 is a flow diagram of an example method 1100C similar to that of method 1100A, but in which the base station transmits a serving cell index to the UE. [Figure 11D] FIG. 11 is a flow diagram of an example method 1100D similar to that of method 1100A, but in which the base station transmits a UL switching Tx state configuration for each non-unique UL switching case. [Figure 11E] 11 is a flow diagram of an example method 1100E similar to that of method 1100A, but in which the base station transmits a UL switching configuration enabling field in the DCI format. [Figure 11F] 11 is a flow diagram of an example method 1100F similar to that of method 1100A, but in which the base station transmits a single UL switching Tx state configuration to the UE. [Figure 11G]11 is a flow diagram of an example method 1100G similar to that of method 1100A, but in which the base station transmits a first UL switching Tx state configuration and a second UL switching Tx state configuration to the UE. DETAILED DESCRIPTION OF THE INVENTION

[0010] Generally, the disclosed technology introduces an UL switching configuration with Tx selection indication for a UE to configure Tx states across cells in at least three frequency bands. The UE triggers UL switching based on UL transmissions scheduled by the base station (via DCI or RRC). In some scenarios, a scheduled UL transmission may be associated with multiple Tx states, which introduces ambiguity between the base station and the UE. With the antenna selection indication in the UL switching configuration, the UE updates the Tx state according to the UL switching rules, thereby resolving the problem of non-unique Tx states.

[0011] Further increasing the number of supported bands to 3 and 4 also increases the number of cases to 6 and 10, respectively, as shown in Tables 2 and 3.

[0012] In one scenario, the last transmission the UE performed on carrier 2 was a two-port transmission (i.e., 0P-2P-0P in case 5), and the UE receives DCI from the gNB scheduling a one-port transmission on carrier 1 (e.g., 1P-0P-0P in case 1, case 3, or case 4). In such a scenario, the UE performs UL switching (e.g., antenna port switching, UL transmit chain switching, or UL Tx switching) to transmit a one-port transmission. In UL switching, the UE switches one of two antenna ports from carrier 2 to carrier 1 and transmits a one-port transmission on carrier 1 using the switched antenna port. However, the UE further decides whether to switch the other antenna port from carrier 2 to carrier 1 (i.e., case 4) or carrier 3 (e.g., case 3), or to keep the other antenna port for carrier 2 (i.e., case 1). That is, upon receiving the DCI, the UE decides to configure its Tx state as case 1, case 3, or case 4. The gNB also determines whether the UE applies the Tx state as Case 1, Case 3, or Case 4 to schedule the next uplink transmission. However, current technology does not provide a means for the UE and the gNB to determine which Tx state applies in such a scenario. A similar problem occurs in a four-band-based scenario. Therefore, this technology shows how to determine a specific Tx state for the UE in the case of UL switching between three bands and four bands. Furthermore, the UE may not support all UL Tx states due to implementation complexity, and therefore this technology further describes how to indicate the supported UL Tx states.

[0013] Table 1 detailed below shows the two carrier UL switching cases and antenna port allocations. [Table 1]

[0014] Similarly, Table 2 detailed below shows the UL switching case of three carriers and the antenna port allocation. [Table 2]

[0015] Table 3 detailed below shows the UL switching cases for four carriers and the antenna port allocation. [Table 3]

[0016] Table 4 shows the antenna port allocation and Tx state association for the non-unique UL switching case, regardless of the current Tx state. [Table 4]

[0017] Similarly, Table 5 shows the antenna port allocation and Tx state association for non-unique UL switching cases with respect to the current Tx state. [Table 5]

[0018] 1A illustrates an exemplary wireless communication system 100 in which the UL switching techniques of this disclosure can be implemented. The wireless communication system 100 includes a UE 102A and a UE 102B, as well as base stations 104, 106A, and 106B of a radio access network (RAN) (e.g., RAN 105) connected to a core network (CN) 110. For ease of reading, the UE 102 is used herein to represent the UE 102A, the UE 102B, or both the UE 102A and the UE 102B, unless otherwise specified. The base stations 104, 106A, and 106B may be any suitable type or types of base stations, such as, for example, an evolved Node B (eNB), a next-generation eNB (ng-eNB), or a 5G Node B (gNB). As a more specific example, the base station 104 may be an eNB or a gNB, and the base stations 106A and 106B may be gNBs.

[0019] Base station 104 supports cell 124, base station 106A supports cell 126A, and base station 106B supports cell 126B. Because cell 124 partially overlaps with both cells 126A and 126B, UE 102 can be within range to communicate with base station 104 and within range to communicate with either base station 106A or 106B (or within range to detect or measure signals from both base stations 106A and 106B) at the same time. The overlap may enable UE 102 to handover between cells (e.g., from cell 124 to cell 126A or 126B) or between base stations (e.g., from base station 104 to base station 106A or base station 106B) before UE 102 experiences a radio link failure. Furthermore, the overlap may enable UE 102 to operate in dual connectivity (DC) with RAN 105. For example, the UE 102 may communicate with the base station 104 (acting as a master node (MN)) and the base station 106A (acting as a secondary node (SN)) in the DC, and may communicate with the base station 106B (acting as an MN) once the handover to the base station 106B is complete. As another example, the UE 102 may communicate with the base station 104 (acting as an MN) and the base station 106A (acting as an SN) in the DC, and may communicate with the base station 104 (acting as an MN) and the base station 106B (acting as an SN) once the SN change is complete.

[0020] More specifically, when the UE 102 is in a DC with the base station 104 and the base station 106A, the base station 104 operates as a master eNB (MeNB), a master ng-eNB (Mng-eNB), or a master gNB (MgNB), and the base station 106A operates as a secondary gNB (SgNB) or a secondary ng-eNB (Sng-eNB).

[0021] The UE 102 includes processing hardware 150, which may include one or more general-purpose processors (e.g., CPUs), computer-readable memory storing machine-readable instructions executable by the general-purpose processor(s), and / or special-purpose processing units. The processing hardware 150 in the exemplary embodiment of FIG. 1A includes a UE UL switching controller 152 configured to manage the UE Tx state for UL transmissions. For example, the UE UL switching controller 152 may be configured to support RRC configurations, procedures, and messaging associated with UL switching procedures, and / or to support necessary operations, as described below.

[0022] The CN 110 can be an Evolved Packet Core (EPC) 111 or a 5th Generation Core (5GC) 160, both shown in FIG. 1A. The base station 104 can be an eNB supporting an S1 interface for communicating with the EPC 111, an ng-eNB supporting an NG interface for communicating with the 5GC 160, or a gNB supporting an NR radio interface and an NG interface for communicating with the 5GC 160. The base station 106A can be an EUTRA-NR DC (EN-DC) gNB (en-gNB) with an S1 interface to the EPC 111, an en-gNB that does not connect to the EPC 111, a gNB supporting an NR radio interface and an NG interface to the 5GC 160, or an ng-eNB supporting an EUTRA radio interface and an NG interface to the 5GC 160. The base stations 104, 106A, and 106B can support an X2 or Xn interface for directly exchanging messages during the scenarios described below.

[0023] Among other components, the EPC 111 may include a Serving Gateway (SGW) 112, a Mobility Management Entity (MME) 114, and a Packet Data Network Gateway (PGW) 116. The SGW 112 is generally configured to forward user plane packets related to voice calls, video calls, Internet traffic, etc., and the MME 114 is configured to manage authentication, registration, paging, and other related functions. The PGW 116 provides connectivity from the UE to one or more external packet data networks (e.g., Internet networks and / or Internet Protocol (IP) Multimedia Subsystem (IMS) networks). The 5GC 160 includes a User Plane Function (UPF) 162, an Access and Mobility Management (AMF) 164, and / or a Session Management Function (SMF) 166. The UPF 162 is generally configured to forward user plane packets related to voice calls, video calls, internet traffic, etc., the AMF 164 is configured to manage authentication, registration, paging and other related functions, and the SMF 166 is configured to manage PDU sessions.

[0024] In general, the wireless communication network 100 may include any suitable number of base stations supporting NR cells and / or EUTRA cells. More specifically, the EPC 111 or 5GC 160 may be connected to any suitable number of base stations supporting NR cells and / or EUTRA cells. While the following examples specifically reference particular CN types (EPC, 5GC) and RAT types (5G NR and EUTRA), in general, the techniques of this disclosure may also be applied to other suitable radio access technologies and / or core network technologies, such as, for example, sixth generation (6G) radio access and / or a 6G core network or 5G NR-6G DC.

[0025] In different configurations or scenarios of the wireless communication system 100, the base station 104 can operate as an MeNB, Mng-eNB, or MgNB, the base station 106B can operate as an MeNB, Mng-eNB, MgNB, SgNB, or Sng-eNB, and the base station 106A can operate as an SgNB or Sng-eNB. The UE 102 can communicate with the base station 104 and the base station 106A or 106B via the same radio access technology (RAT), such as EUTRA or NR, or via different RATs.

[0026] When the base station 104 is an MeNB and the base station 106A is an SgNB, the UE 102 may be in an EN-DC with the MeNB 104 and the SgNB 106A. When the base station 104 is an Mng-eNB and the base station 106A is an SgNB, the UE 102 may be in a Next Generation (NG) EUTRA-NR DC (NGEN-DC) with the Mng-eNB 104 and the SgNB 106A. When the base station 104 is an MgNB and the base station 106A is an SgNB, the UE 102 may be in an NR-NR DC (NR-DC) with the MgNB 104 and the SgNB 106A. When the base station 104 is an MgNB and the base station 106A is an Sng-eNB, the UE 102 may be in an NR-EUTRA DC (NE-DC) with the MgNB 104 and the Sng-eNB 106A.

[0027] 1B illustrates an exemplary distributed implementation of any one or more of base stations 104, 106A, 106B. In this implementation, base station 104, 106A, or 106B includes a central unit (CU) 172 and one or more distributed units (DUs) 174. CU 172 includes processing hardware (e.g., one or more general-purpose processors (e.g., CPUs) and computer-readable memory storing machine-readable instructions executable by the general-purpose processor(s)) and / or special-purpose processing units. For example, CU 172 can include processing hardware 130 or 140 of FIG. 1A.

[0028] Each of the DUs 174 may also include processing hardware (one or more general-purpose processors (e.g., CPUs) and computer-readable memory storing machine-readable instructions executable on the one or more general-purpose processors) and / or special-purpose processing units. For example, the processing hardware may include a medium access control (MAC) controller configured to manage or control one or more MAC operations or procedures (e.g., random access procedures) and a radio link control (RLC) controller configured to manage or control one or more RLC operations or procedures when the base station (e.g., base station 106A) operates as an MN or an SN. The processing hardware may also include a physical layer controller configured to manage or control one or more physical layer operations or procedures.

[0029] In some embodiments, the CU 172 may include a logical node CU-CP 172A that hosts the control plane portion of the Packet Data Convergence Protocol (PDCP) protocol and / or the Radio Resource Control (RRC) protocol for the CU 172. The CU 172 may also include logical node(s) CU-UP 172B that host the user plane portion of the PDCP protocol and / or the Service Data Adaptation Protocol (SDAP) protocol for the CU 172. The CU-CP 172A may transmit UL switching control information.

[0030] The CU-CP 172A can be connected to multiple CU-UPs 172B via an E1 interface. The CU-CP 172A selects an appropriate CU-UP 172B for a service requested by the UE 102. In some embodiments, a single CU-UP 172B can be connected to multiple CU-CPs 172A via an E1 interface. The CU-CP 172A can be connected to one or more DUs 174 via an F1-C interface. The CU-UP 172B can be connected to one or more DUs 174 via an F1-U interface under the control of the same CU-CP 172A. In some embodiments, one DU 174 can be connected to multiple CU-UPs 172B under the control of the same CU-CP 172A. In such embodiments, connectivity between the CU-UP 172B and the DU 174 is established by the CU-CP 172A using a bearer context management function.

[0031] FIG. 2 illustrates a simplified example protocol stack 200 according to which a UE 102 can communicate with an eNB / ng-eNB or gNB (e.g., one or more of base stations 104, 106A, 106B).

[0032] In the exemplary stack 200, a EUTRA physical layer (PHY) 202A provides transport channels to a EUTRA MAC sublayer 204A, which in turn provides logical channels to a EUTRA RLC sublayer 206A. The EUTRA RLC sublayer 206A then provides RLC channels to a EUTRA PDCP sublayer 208 and, in some cases, to an NR PDCP sublayer 210. Similarly, an NR PHY 202B provides transport channels to an NR MAC sublayer 204B, which in turn provides logical channels to an NR RLC sublayer 206B. The NR RLC sublayer 206B then provides RLC channels to the NR PDCP sublayer 210. In some embodiments, the UE 102 supports both EUTRA and NR stacks, supports handover between EUTRA and NR base stations, and / or supports DC over the EUTRA and NR interfaces, as shown in FIG. 2 . Additionally, as shown in FIG. 2, the UE 102 can support layering of an NR PDCP 210 over the EUTRA RLC 206A and an SDAP sublayer 212 over the NR PDCP sublayer 210.

[0033] The EUTRA PDCP sublayer 208 and the NR PDCP sublayer 210 receive packets, which may be referred to as service data units (SDUs) (e.g., from an Internet Protocol (IP) layer layered directly or indirectly on the PDCP layer 208 or 210), and output packets, which may be referred to as protocol data units (PDUs) (e.g., to the RLC layer 206A or 206B). For simplicity, this disclosure will refer to both SDUs and PDUs as "packets" unless the distinction between SDUs and PDUs is relevant. Packets may contain application content for different services (e.g., IPv4 / IPv6 multicast distribution, IPTV, software distribution over wireless, group communication, IoT applications, V2X applications, and / or emergency messages related to public safety).

[0034] In the control plane, the EUTRA PDCP sublayer 208 and the NR PDCP sublayer 210 can provide SRBs to exchange, for example, RRC messages or non-access stratum (NAS) messages. In the user plane, the EUTRA PDCP sublayer 208 and the NR PDCP sublayer 210 can provide DRBs to support data exchange. The data exchanged over the NR PDCP sublayer 210 can be SDAP PDUs, Internet Protocol (IP) packets, or Ethernet packets.

[0035] In a scenario where the UE 102 operates in an EN-DC where the base station 104 acts as an MeNB and the base station 106A acts as an SgNB, the wireless communication system 100 can provide the UE 102 with an MN-terminated bearer using the EUTRA PDCP sublayer 208 or an MN-terminated bearer using the NR PDCP sublayer 210. The wireless communication system 100 can also provide the UE 102 with an SN-terminated bearer using only the NR PDCP sublayer 210 in various scenarios. The MN-terminated bearer may be an MCG bearer, a split bearer, or an MN-terminated SCG bearer. The SN-terminated bearer may be an SCG bearer, a split bearer, or an SN-terminated MCG bearer. The MN-terminated bearer may be an SRB (e.g., SRB1 or SRB2) or a DRB. The SN-terminated bearer may be an SRB or a DRB.

[0036] To simplify the following description, UE 102 represents UE 102A and UE 102B unless explicitly stated otherwise.

[0037] 3 illustrates an exemplary scenario 300 depicting a message passing procedure for UL switching in which a UE 102 is equipped with a first and second Tx. The procedure begins with event 302, in which a base station 104 communicates with the UE 102 to request the UE's capabilities for UL switching. In response to event 302, the UE 102 transmits UL Tx switching capabilities for multiple (e.g., two, three, and / or four) bands to the base station 104 (304). In some embodiments, the capabilities for UL Tx switching include UL switching-related information such as band combinations, band pair lists, MIMO capabilities per component carrier, supported UL switching options, and switching periods. At event 305, the base station 104 receives UL Tx switching capabilities for multiple (e.g., two, three, and / or four) bands (304). The base station 104 then transmits 312 the cell group configuration to the UE 102, where the cell group configuration includes an SpCell configuration (e.g., SpCellConfig), an SCell configuration (e.g., SCellConfig), and other parameters for the UE 102 to transmit and / or receive signals from multiple cells. The base station 104 then transmits 314 the UL switching configuration to the UE 102, where the UL switching configuration includes a carrier index (e.g., uplinkTxSwitchingCarrier), an UL switching option, an ambiguous Tx state resolution indication (e.g., uplinkTxSwitching-DualUL-TxState), etc.

[0038] In a further embodiment, the base station 104 then transmits (322) the configured grant to the UE 102 and schedules one or more PUSCH transmissions, including scheduling (342) a third PUSCH transmission. The base station 104 then transmits (324) a first DCI to the UE 102, which schedules (344) the first PUSCH transmission. In response to receiving (324) the first DCI, the UE 102 determines (334) a first Tx state for the first and second Txs and transmits (344) the first PUSCH to the base station 104. The base station 104 then transmits (326) a second DCI to the UE 102, which schedules (326) a second PUSCH transmission 346. In response to the second DCI 326, the UE 102 determines (336) a second Tx state for the first and second Txs and transmits (346) a second PUSCH to the base station 104. If the UE 102 determines (336) that the second Tx state is different from the first Tx state, the UE performs Tx switching. Then, in accordance with the configured grant, the UE 102 determines (332) a third Tx state for the first and second Txs and transmits (342) a third PUSCH to the base station 104.

[0039] 4A illustrates an exemplary scenario 400A similar to scenario 300. Differences between 400A and 300 are described below. In block 402, the UE 102 communicates with the MN 104 and the SN 106 to request the UE's capabilities for UL switching. In response to event 402, the UE 102 transmits UL Tx switching capabilities for multiple bands (e.g., two, three, and / or four) to the MN 104 (404). In event 405, the MN 104 receives the UL Tx switching capabilities for multiple bands (e.g., two, three, and / or four). The MN 104 then transmits an SN message to the SN 106 (406) including the UL Tx switching capabilities for multiple bands (e.g., two, three, and / or four). In accordance with the SN message, the SN 106 transmits a cell group configuration including the UL switching configuration to the UE 102 (410A).

[0040] 4B shows an exemplary scenario 400A that is similar to scenarios 300 and 400A. The differences between scenario 400B and scenarios 300 or 400A are explained below. According to the SN message, the SN 106 sends a cell group configuration including an UL switching configuration to the MN 104 (410B). The MN 104 then sends a cell group configuration including an UL switching configuration to the UE 102 (411B).

[0041] 5 illustrates a general method 500 of a UE (e.g., UE 102) procedure for UL switching, which may be at least partially applicable to scenario 300 of FIG. 3, scenario 400A of FIG. 4A, and / or scenario 400B of FIG. 4B. At block 512, UE 102 receives configurations 1, ..., N including configuration parameters for cells 1, ..., N, respectively, where N is an integer greater than 1 (e.g., cell group configuration, event 312). At block 514, UE 102 receives an UL switching configuration (e.g., event 314). At block 520, UE 102 receives a configured grant for transmitting an UL grant and / or PUSCH(s) in DCI from a base station (e.g., BS 104) (e.g., events 322, 324, and 326). At block 530, the UE 102 determines to send a UL transmission in one of cells 1, ..., N and determines a Tx state for the UL transmission (e.g., events 332, 334, and 336). Finally, at block 550, the UE 102 transmits a UL transmission according to the Tx state (e.g., events 342, 344, and 346).

[0042] FIGS. 6, 7A, 7B, 8, 9A, and 9B show detailed procedures and variations of method 500 for a UE to determine a Tx state. Generally speaking, similar events in FIGS. 5-9B are labeled with similar reference numbers (e.g., event 512 is similar to event 612 in FIG. 6, event 712 in FIGS. 7A and 7B, etc.), with differences discussed below. Except for the differences shown in the figures and discussed below, any alternative implementations described with respect to a particular event (e.g., messaging and processing) may also apply to similarly numbered events in other figures. Furthermore, it will be understood that FIGS. 6-9B may depict expanded views of events in FIG. 5. For example, block 630 in FIG. 6, including blocks 632, 634, 636, and 637, may expand upon the expanded view of block 530 in FIG. 5, indicated by the dashed lines surrounding the component events. It will therefore be understood that implementations with such expanded events may be applied to the version in FIG. 5, and vice versa.

[0043] 6 illustrates an example method 600 of a UE procedure similar to method 500, with differences described below. At block 614, the UE (e.g., UE 102) receives an UL switching configuration (e.g., events 314, 514) including a serving cell index (e.g., uplinkTxSwitchingCarrier) for a non-unique UL switching case. At block 632, if the PUSCH transmission does not utilize a Tx state(s) update, flow proceeds to block 640, where the UE 102 transmits a PUSCH according to the Tx state. At block 632, if the PUSCH transmission utilizes a Tx state update, flow proceeds to block 634. At block 634, if the updated Tx state(s) are unique, flow proceeds to block 636. At block 636, the UE updates the Tx state(s) based on the scheduled cell(s) of the PUSCH transmission. In block 634, if the updated Tx state(s) are not unique, then flow proceeds to block 637. In block 637, the UE updates the Tx state(s) based on the scheduled cell(s) of the PUSCH transmission and the serving cell index (from event 614) of the unscheduled Tx. Then, flow proceeds from block 636 and / or 637 to block 640.

[0044] As an example of method 600 applicable to scenario 300, the base station 104 transmits 312 (e.g., event 512) a cell group configuration to the UE 102, including first, second, and third serving cell indices for the first, second, and third cells in the first, second, and third bands, respectively. The base station 104 transmits 314 (e.g., event 614) an UL switching configuration to the UE 102. The UE 102 uses the first and second Tx for UL transmissions (thus, Tx state and antenna port assignment may be determined according to Table 2). The base station 104 transmits 324 a first DCI to the UE 102, the first DCI scheduling a two-port PUSCH transmission in the second cell (0P-2P-0P). At event 334, because case 5 (0T-2T-0T) is associated with antenna port assignment 0P-2P-0P, the UE 102 configures a first and second Tx for the second cell (e.g., event 636). The UE 102 transmits (344) a first PUSCH to the base station 104 in the Tx state of case 5 (0T-2T-0T). The base station 104 then transmits (326) a second DCI to the UE 102, which schedules a two-port PUSCH transmission in the first cell (1P-0P-0P). At event 336, the UE 102 configures (e.g., event 636) a first Tx for the first cell and configures (e.g., event 637) a second Tx for the cell using the serving cell index indicated in the UL switching configuration. For example, if the serving cell index indicates a second cell, the UE 102 configures a second Tx for the second cell, and then the Tx state becomes case 1 (1T-1T-0T). Similarly, if the cell index indicates a first cell, the UE 102 configures a second Tx for the first cell, and then the Tx state becomes case 4 (2T-0T-0T). Finally, the UE 102 transmits (346) a second PUSCH in the Tx state of case 4 (2T-0T-0T).

[0045] 7A illustrates an example method 700A of UE procedures similar to methods 500 and 600, with differences described below. At block 714A, a UE (e.g., UE 102) receives an UL switching configuration (e.g., events 314, 514) including priority values ​​(e.g., uplinkSwitchingPriority) of 1, ..., N for cell(s) / band(s) of 1, ..., N, respectively. At block 737A, the UE 102 updates its Tx state based on the scheduled cell(s) for PUSCH transmission and the UL Tx switching priority configured in the UL switching configuration.

[0046] As an example of method 700A applicable to scenario 300, the base station 104 configures 312 (e.g., event 512) a cell group configuration for the UE 102 including a first cell, a second cell, and a third cell on a first band, a second band, and a third band, respectively. The base station 104 transmits 314 (e.g., event 714A) an UL switching configuration to the UE 102 including first, second, and third priorities for the first, second, and third cells. The UE 102 uses the first and second Tx for UL transmission (thus, Tx state and antenna port assignment can be determined according to Table 2). The base station 104 transmits 324 a first DCI to the UE 102, the first DCI scheduling a two-port PUSCH transmission in the second cell (0P-2P-0P). At event 334, the UE 102 configures the first and second antennas for the second cell (Case 5, 0T-2T-0T) because Case 5 is associated with antenna port assignment 0P-2P-0P. The UE 102 transmits 344 a first PUSCH to the base station 104 in the Tx state of Case 5 (0T-2T-0T). The base station 104 then transmits 326 a second DCI to the UE 102, which schedules a two-port PUSCH transmission in the first cell (1P-0P-0P). At event 336, the UE 102 configures a first Tx for the first cell (e.g., Event 636) and a second Tx for the cell with the highest priority value (e.g., Event 737A). For example, if the cell with the highest priority value is the second cell, the UE 102 configures a second Tx for the second cell, and thus the Tx state becomes case 1 (1T-1T-0T). Similarly, if the cell with the highest priority value is the first cell, the UE 102 configures a second Tx for the first cell, and thus the Tx state becomes case 4 (2T-0T-0T). The UE 102 then transmits 346 a second PUSCH in the Tx state of case 4 (2T-0T-0T).

[0047] FIG. 7B illustrates an example method 700B of UE procedures similar to methods 500 and 600, but with differences described below.

[0048] At block 712B, the UE (e.g., UE 102) receives configurations 1, ..., N including configuration parameters and serving cell indices 1, ..., N for cells 1, ..., N, respectively, where N is an integer greater than 1. At block 737B, the UE 102 updates the Tx state based on the scheduled cell(s) and serving cell indexes of the PUSCH transmission.

[0049] An example of applying method 700B to scenario 300 is similar to an example of applying method 700A to scenario 300, with differences described below. The base station 104 sends 312 to the UE 102 a cell group configuration including serving cell indices 1, ..., N for cells 1, ..., N, respectively. At event 336, the UE configures a first Tx for the first cell (e.g., event 636) and a second Tx for the cell with the smallest serving cell index (e.g., event 737B). For example, if the cell with the smallest serving cell index is the second cell, the UE 102 configures a second Tx for the second cell, and thus the Tx state becomes case 1 (1T-1T-0T). Similarly, if the cell with the smallest serving cell index is the first cell, the UE 102 configures a second Tx for the first cell, and thus the Tx state becomes case 4 (2T-0T-0T). Next, the UE 102 transmits (346) a second PUSCH in a Tx state of Case 4 (2T-0T-0T).

[0050] 8 illustrates an example method 800 of UE procedures similar to methods 500 and 600, with differences described below. At block 814, the UE (e.g., UE 102) receives a UL switching configuration including a Tx state indication for each of the non-unique UL switching cases (e.g., events 314, 514). At block 837, the UE 102 updates the Tx state based on the scheduled cell(s) for PUSCH transmission and the Tx state indication for the non-unique UL switching cases.

[0051] In some implementations of method 800, a base station (e.g., BS 104) indicates a Tx state for each antenna port assignment associated with a non-unique UL switching case. For example, the base station 104 configures the UE 102 with UL switching in cells on three bands. In some implementations, the base station indicates the Tx state and antenna port assignment as shown in Table 4. As shown in Table 4, the antenna port assignment 1P-0P-0P is associated with Tx state case 3 (1T-0T-1T). When the UE 102 transmits a one-port PUSCH transmission (1P-0P-0P) on the first cell and the UE 102 updates the Tx state for the transmission, the UE 102 configures a first Tx for the first cell and a second Tx for the third cell (case 3 1T-0T-0T), regardless of the current Tx state. Similarly, the antenna port assignment 0P-1P-0P is associated with Tx state case 1 (1T-1T-0T), as also shown in Table 4. When the UE 102 transmits a 1-port PUSCH transmission (0P-1P-0P) on the second cell and the UE 102 updates the Tx state for the transmission, the UE 102 configures a first Tx for the first cell and a second Tx for the second cell (case 1 1T-1T-0T), regardless of the current Tx state.

[0052] In some embodiments, in block 814, the base station 103 indicates one Tx state for the antenna port assignment associated with the non-unique UL switching case and the current Tx state of the UE 102. Table 5 illustrates such an association, where the antenna port assignment can be associated with the same or different Tx state with respect to the current Tx state in the UE 102. For example, in one scenario, the UE 102 transmits a 1-port PUSCH in the first cell (1P-0P-0P) and updates the Tx state for transmission. If the current Tx state of the UE 102 is in case 2 (0T-1T-1T), the UE 102 configures the first and second Tx (case 3 1T-0T-1T) for the first and third cells, respectively (as seen in the first row of Table 5). Similarly, if the current Tx state of UE 102 is in case 6 (0T-0T-2T), UE 102 configures the first and second Tx (case 1 1T-1T-0T) for the first and second cells, respectively (as seen in the third row of Table 5).

[0053] In some embodiments, the base station 104 configures, for the UE 102, first and second Tx state indications associated with Table 4 and Table 5, respectively. When the UE 102 updates the Tx state for a non-unique UL switching case, the UE checks whether the second Tx state indication (Table 5) is applicable. If the second Tx state indication (Table 5) is not applicable, the UE updates the Tx state according to the first Tx state indication (Table 4). Otherwise, the UE updates the Tx state according to the second Tx state indication (Table 5).

[0054] As an example of RRC signaling, Table 4 provides a first table of antenna port assignments associated with non-unique UL switching cases (e.g., 1P-0P-0P, 0P-1P-0P, and 0P-0P-1P). In some embodiments, a second table of all Tx states (e.g., 1T-1T-0T, 0T-1T-1T, 1T-0T-1T, 2T-0T-0T, 0T-2T-0T, and 0T-0T-2T) is also utilized. The base station 104 then configures a list of integers for the UE 102. In some embodiments, a first integer indicates the Tx state of the first non-unique UL switching case in the first table (e.g., 1P-0P-0P), and the value of the first integer indicates the Tx state in the second table (e.g., the value of Tx state 1T-1T-0T is 1). Similarly, the second integer indicates the Tx state of a second non-unique UL switching case (e.g., 1P-0P-0P) in the first table, and the value of the second integer indicates another Tx state in the second table. Similarly, in some embodiments, Table 5 is similarly implemented using the first table, which includes the current Tx state and antenna port assignments for the non-unique UL switching cases.

[0055] As another example of RRC signaling in Table 4, the base station associates a non-unique switching case with a Tx state using the naming of RRC parameters. For example, the base station configures the parameter nonUniqueSwitchingCase1P-0P-0P with a value selected from the enumeration {1T-1T-0T, 0T-1T-1T, 1T-0T-1T, 2T-0T-0T, 0T-2T-0T, 0T-0T-2T}. The UE 102 then updates the Tx state for a 1P-0P-0P UL transmission, and if the value of nonUniqueSwitchingCase1P-0P-0P is 1T-1T-0T, the UE 102 switches the Tx state to 1T-1T-0T for the transmission. Similarly, in some embodiments, the base station 104 configures the parameters nonUniqueSwitchingCase0P-1P-0P and nonUniqueSwitchingCase0P-0P-1P in the same manner.

[0056] 9A illustrates an example method 900A of a UE procedure similar to methods 500 and 600, but with differences described below. At block 914, the UE (e.g., UE 102) receives an UL switching configuration (e.g., events 314, 514), which enables a field in a DCI format to indicate the unassigned Tx cell(s) / band(s) for UL switching. At block 924, the UE 102 receives a DCI, which schedules a PUSCH transmission and includes the unassigned Tx cell(s) / band(s) for UL switching indicator. At block 937A, the UE 102 updates the Tx state based on the scheduled cell(s) for the PUSCH transmission and the unassigned Tx cell(s) / band(s) indicator(s) in the scheduling DCI.

[0057] In some implementations, if the UE 102 transmits a PUSCH without updating the Tx state, the UE 102 ignores the unassigned Tx cell(s) / band indicator in the scheduling DCI.

[0058] As an example in which method 900A is applicable to scenario 300, the base station 104 sends 314 to the UE 102 an UL switching configuration for enabling the cell(s) / band indicator field in the DCI. The base station 104 then sends 326 a second DCI to the UE 102 and schedules 346 a second PUSCH transmission. When the UE 102 sends 346 the second PUSCH to the base station 104 and uses a Tx state update to transmit the second PUSCH, the UE 102 determines the Tx state according to the unassigned Tx cell(s) / band indicator in the second DCI (e.g., event 334 of 937A).

[0059] 9B shows an example method 900B of a UE procedure similar to methods 500, 600, and 900A, but with differences described below. At block 922B, the UE (e.g., UE 102) receives a configured grant to transmit PUSCH(s) (e.g., third PUSCH 342) (e.g., event 322, 522). At block 935B, if the PUSCH is scheduled by the DCI, flow proceeds to block 937A. At block 935B, if the PUSCH is not scheduled by the DCI, flow proceeds to block 937B. At block 937B, the UE 102 updates the Tx state based on the scheduled cell(s) of the PUSCH transmission and the unassigned Tx cell(s) / band indicator in the UL of the last scheduling DCI.

[0060] An example of applying method 900B to scenario 300 is similar to the example of method 900A applicable to scenario 300, with differences described below. UE 102 receives (322) a configured grant from base station 104 that schedules (342) a third PUSCH transmission. In some implementations, when UE 102 transmits (342) the third PUSCH to base station 104 and utilizes a Tx state update, UE 102 determines the Tx state according to the unassigned Tx cell(s) / band indicator in the second DCI of 326 (the last scheduling DCI before block 342) (e.g., event 332 of 937B).

[0061] The disclosed methods can also be applied to other UL channels, such as PUCCH transmissions triggered by dynamically or semi-persistently scheduled downlink transmissions (e.g., HARQ feedback, scheduling requests), or RRC-configured UL transmissions (e.g., channel state information reports).

[0062] In some implementations, the serving cell index, cell index, carrier index, cell(s) / band indication, and Tx state indication of methods 600, 700B, 800, 900A, and 900B refer to a carrier index (e.g., uplinkTxSwitchingCarrier with a value of the enumeration {carrier1, carrier2, carrier3}) configured in the UL switching configuration (e.g., uplinkTxSwitching) in each serving cell configuration (e.g., ServingCellConfig). If the frequency ranges of multiple cells are in the same band and can operate with a single Tx in the UE, the base station configures the UE with the same carrier index for these cells.

[0063] In some other embodiments, the serving cell index, cell index, carrier index, cell(s) / band indication, and Tx state indication of methods 600, 700B, 800, 900A, and 900B refer to a cell index (e.g., a secondary cell index, SCellIndex) configured in a cell group configuration (e.g., CellGroupConfig) for cross-carrier scheduling. In some embodiments, for a primary cell (PCell or a special cell within a cell group), the cell index is 0, a default value specified in the 3GPP® standard, or a cell index (e.g., PCellIndex) configured by the base station.

[0064] 10A, 10B, and 10C illustrate methods for applying one or more techniques from methods 600, 700A, 700B, 800, 900A, and 900B and legacy Tx state configurations (e.g., uplinkTxSwitching-DualUL-TxState) in determining the Tx state. Differences between these methods and the other methods described above are explained in more detail below. As with FIGS. 6-9B, events in FIGS. 10A-10C that are similar to events in FIGS. 5-9B are labeled with similar reference numbers (e.g., event 512 is similar to event 1012 in FIGS. 10A-10C), and differences are explained below, where appropriate. Except for the differences shown in the figures and discussed below, any of the alternative implementations described with respect to particular events (e.g., messaging and processing) may also be applied to similarly numbered events in other figures.

[0065] 10A illustrates an example method 1000A similar to method 500, but with differences described below to address the behavior of a UE communicating with a RAN. In some embodiments, the Tx state determination procedure is based on a single UL switching Tx state configuration. At block 1014A, the UE receives a single UL switching Tx state configuration from the RAN (e.g., 514, 614, 714A, 814, 914A, 914B). At block 1035A, the UE 102 updates the Tx state according to the single UL switching Tx state configuration.

[0066] 10B illustrates an example method 1000B that is similar to methods 500 and 1000A, but with differences described below. At block 1014B, the UE receives first and second UL switching Tx state configurations from the RAN (e.g., 514, 614, 714A, 814, 914A, 914B). At block 1035B, the UE 102 updates the Tx state according to the first and second UL switching Tx state configurations.

[0067] In some examples, the base station 104 configures the method 900A / 900B using techniques from the methods 600 / 700A / 700B / 800. For PUSCH scheduled by the DCI format, the UE 102 applies the method 900A / 900B to update the Tx state. Otherwise, the UE 102 applies techniques according to the methods 600 / 700A / 700B / 800 to update the Tx state.

[0068] In some other examples, the base station 104 configures (e.g., at events 312, 314) a first UL switching Tx state configuration (e.g., uplinkTxSwitching-DualUL-TxState) and a second UL switching Tx state configuration (e.g., events 510, 614, 714A, 712B, 814, 914A) for the UE 102. In some embodiments, if the value of uplinkTxSwitching-DualUL-TxState is 2T, the UE 102 applies the first UL switching Tx state configuration to update the Tx state when encountering a non-unique UL switching case. In further embodiments, if the value of uplinkTxSwitching-DualUL-TxState is 1T, the UE applies the second UL switching Tx state configuration to update the Tx state when encountering a non-unique UL switching case.

[0069] 10C shows an example method 1000C similar to methods 1000A and 1000B. When a non-unique UL switching case occurs, the UE (e.g., UE 102) applies blocks 1050A and 1050B to determine a Tx state for UL switching. If the determined Tx state is the same as the current Tx state at block 1031C, flow proceeds to block 1043C. At block 1043C, the UE 102 transmits a UL transmission according to the current transmission configuration. If the determined Tx state is not the same as the current Tx state at block 1031C, flow proceeds to block 1037C. At block 1037C, the UE 102 updates the current transmission configuration to a new transmission configuration according to the determined Tx state. At block 1041C, the UE 102 transmits a UL transmission according to the updated transmission configuration.

[0070] Figures 11A, 11B, 11C, 11D, 11E, 11F, and 11G illustrate base station procedures for configuring UL switching Tx station configurations and / or indicating cell(s) / band for unscheduled Tx to a UE. As with Figures 6-10C, events in Figures 11A-11G that are similar to events in Figures 5-10C are labeled with similar reference numbers (e.g., event 512 is similar to event 1112 in Figures 11A-11G), and differences, where appropriate, are explained below. Except for the differences shown in the figures and discussed below, any of the alternative implementations described with respect to particular events (e.g., messaging and processing) may also apply to similarly numbered events in other figures.

[0071] 11A shows an example method 1100A that reflects a base station perspective similar to the UE perspective of method 600. The flow begins at block 1112, where the base station 104 sends to the UE 102 configurations 1, ..., N, including configuration parameters for cells 1, ..., N, respectively, where N is an integer greater than 1 (e.g., event 512). At block 1114A, the base station 104 sends to the UE 102 a cell(s) / band indication of a UL switching Tx state for unscheduled Tx (e.g., event 614). At block 1121, the base station 104 sends DL transmissions on cells 1, ..., N to the UE 102 according to configurations 1, ..., N (e.g., event 520). At block 1123A, the base station determines a Tx state according to the cell(s) / band indication of a UL switching Tx state for unscheduled Tx. In block 1120, the base station 104 schedules the UE 102 to transmit an UL transmission in one of cells 1, ..., N according to the Tx state. In block 1140, the base station receives an UL transmission from the UE (e.g., event 540).

[0072] 11B shows an example method 1100B that reflects a base station perspective similar to the UE perspective of method 700A. Method 1100B is similar to method 1100A, with differences described below. At block 1114B, the base station 104 transmits to the UE 102 UL Tx switching priorities 1, ..., N for cells 1, ..., N, respectively (e.g., event 714A). At block 1123B, the base station 104 determines the Tx state according to the UL Tx switching priorities 1, ..., N associated with cells 1, ..., N, respectively.

[0073] 11C shows an example method 1100C that reflects a base station perspective similar to the UE perspective of method 700B. Method 1100C is similar to method 1100A, with differences described below. At block 1112C, the base station 104 sends to the UE 102 configurations 1, ..., N including configuration parameters for cells 1, ..., N and serving cell indices 1, ..., N, respectively, where N is an integer greater than 1 (e.g., 712B). At block 1114, the base station 104 sends an UL switching configuration to the UE 102 (e.g., event 514). At block 1123C, the base station 104 determines Tx states according to the serving cell indices 1, ..., N, where the serving cell indices 1, ..., N are associated with cells 1, ..., N, respectively.

[0074] 11D shows an example method 1100D that reflects a base station perspective similar to the UE perspective of method 800. Method 1100D is similar to method 1100A, with differences described below. At block 1114D, the base station 104 sends the UL switching Tx state configuration for each non-unique UL switching case to the UE 102. At block 1123D, the base station 104 determines the Tx state according to the UL switching Tx state configuration for each non-unique UL switching case.

[0075] 11E shows an example method 1100E that reflects a base station perspective similar to the UE perspective of methods 900A and 900B. Method 1100E is similar to method 1100A, with differences described below. In block 1114E, the base station 104 sends to the UE 102 an UL switching configuration that enables a field in a DCI format that indicates the Tx state (e.g., serving cell index) of unscheduled Txs. In block 1123E, the base station 104 determines the Tx state according to upcoming transmissions on serving cell indexes 1, ..., N. In block 1120E, the base station 104 schedules the UE 102 to transmit an UL transmission on one of cells 1, ..., N and indicates the Tx state (e.g., serving cell index) of unscheduled Txs in the scheduling DCI.

[0076] 11F shows an example method 1100F that reflects a base station perspective similar to the UE perspective of method 1000A. Method 1100F is similar to method 1100A, with differences described below. At block 1114F, the base station 104 sends a single UL switching Tx state configuration to the UE 102. At block 1123F, the base station 104 determines a Tx state according to the single UL switching Tx state configuration.

[0077] 11G shows an example method 1100G that reflects a base station perspective similar to the UE perspective of method 1000B. Method 1100G is similar to method 1100A, with differences described below. At block 1114G, the base station 104 transmits a first UL switching Tx state configuration (e.g., uplinkTxSwitching-DualUL-TxState) and a second UL switching Tx state configuration to the UE 102. At block 1123G, the base station 104 determines a Tx state according to the first UL switching Tx state configuration (e.g., uplinkTxSwitching-DualUL-TxState) and the second UL switching Tx state configuration.

[0078] In some embodiments, the base station 104 proceeds from block 1121 to block 1120 (e.g., skipping events 1123A, 1123B, 1123C, 1123D, 1123E, 1123F, and 1123G).

[0079] The following additional considerations apply to the above discussion:

[0080] In some embodiments, "message" is used and can be replaced with "information element (IE)." In some embodiments, "IE" is used and can be replaced with "field." In some embodiments, "configuration" can be replaced with "configurations" or configuration parameters.

[0081] User equipment (e.g., UE 102) capable of implementing the techniques of this disclosure may be any suitable device capable of wireless communication, such as a smartphone, tablet computer, laptop computer, mobile game console, point-of-sale (POS) terminal, health management device, drone, camera, media streaming dongle or other personal media device, wearable device such as a smartwatch, wireless hotspot, femtocell, or broadband router. Furthermore, user equipment may in some cases be embedded in an electronic system such as a vehicle head unit or advanced driver assistance system (ADAS). Furthermore, user equipment may operate as an Internet of Things (IoT) device or a mobile internet device (MID). Depending on the type, user devices may include one or more general-purpose processors, computer-readable memory, a user interface, one or more network interfaces, one or more sensors, etc.

[0082] Certain embodiments are described in this disclosure as including logic or several components or modules. The modules may be software modules (e.g., code or machine-readable instructions stored on a non-transitory machine-readable medium) or hardware modules. A hardware module is a tangible unit that can perform certain operations and may be configured or arranged in a certain manner. A hardware module may include dedicated circuitry or logic that is permanently configured (e.g., as a dedicated processor, such as a field programmable gate array (FPGA) or application-specific integrated circuit (ASIC), or a digital signal processor (DSP)) to perform certain operations. A hardware module may also include programmable logic or circuitry (e.g., contained within a general-purpose processor or other programmable processor) that is temporarily configured by software to perform certain operations. The decision to implement a hardware module in dedicated and permanently configured circuitry or in temporarily configured circuitry (e.g., configured by software) may depend on cost and time considerations.

[0083] If implemented in software, the techniques may be provided as part of an operating system, a library used by multiple applications, a specific software application, etc. The software may be executable by one or more general-purpose processors or one or more special-purpose processors.

[0084] After reading this disclosure, those skilled in the art will recognize further additional and alternative structural and functional designs for managing radio bearers through the principles disclosed herein. Thus, while particular embodiments and applications have been illustrated and described, it will be understood that the disclosed embodiments are not limited to the precise structure and components disclosed herein. Various modifications, changes, and variations apparent to those skilled in the art may be made in the arrangement, operation, and details of the methods and apparatus disclosed herein without departing from the spirit and scope of the appended claims.

Claims

1. 1. A method in a user equipment (UE) comprising a first transmitter and a second transmitter, the method comprising: transmitting a first uplink transmission using the first transmitter switched to a first frequency band and using a second transmitter switched to a second frequency band; receiving, from a radio access network (RAN), an uplink switching configuration for a second uplink transmission using the first transmitter, the uplink switching configuration including: (i) a first parameter indicating whether to switch the second transmitter away from the second frequency band; and (ii) a second parameter indicating to which frequency band the UE should switch the second transmitter; transmitting the second uplink transmission in accordance with the uplink switching configuration; A method comprising:

2. The method of claim 1 , wherein the first parameter is a binary parameter.

3. The method of claim 2 , wherein the first parameter is uplinkTxSwitching-DualUL-TxState.

4. 4. The method of claim 1, wherein the second parameter indicates a transmission (Tx) state in which each of the first transmitter and the second transmitter is unambiguously mapped to a respective frequency band within a set of frequency bands.

5. The method of claim 4 , wherein the set of frequency bands includes exactly three frequency bands.

6. The method of claim 4 , wherein the set of frequency bands includes exactly four frequency bands.

7. The method of claim 1 , wherein the second parameter indicates a cell associated with the respective frequency band.

8. The method of claim 1 , wherein the first uplink transmission and the second uplink transmission are Physical Uplink Shared Channel (PUSCH) transmissions.

9. 9. The method of claim 8, wherein the uplink switching configuration is received in downlink control information (DCI) that schedules the PUSCH transmission.

10. switching the first transmitter to a third frequency band for the second uplink transmission.

10. The method of claim 1, further comprising:

11. A user equipment (UE) comprising one or more processors and configured to perform the method of any one of claims 1 to 10.

12. 1. A method in a radio access network (RAN) node, comprising: receiving a first uplink transmission over a first frequency band and a second frequency band from a user equipment (UE) having a first transmitter and a second transmitter; transmitting to the UE an uplink switching configuration for a second uplink transmission over a third frequency band, the uplink switching configuration including (i) a first parameter indicating whether to switch the second transmitter away from the second frequency band, and (ii) a second parameter indicating to which frequency band the UE should switch the second transmitter; A method comprising:

13. 13. The method of claim 12, wherein the first uplink transmission and the second uplink transmission are Physical Uplink Shared Channel (PUSCH) transmissions.

14. 13. The method of claim 12, wherein the uplink switching configuration is transmitted in downlink control information (DCI) that schedules the PUSCH transmission.

15. A Radio Access Network (RAN) node comprising one or more processors and configured to perform the method of any one of claims 12 to 14.

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