Transmitter switching and band pair pattern for wireless communication

Abstract

The present document relates generally to wireless communications, including a user equipment that determines to perform an uplink (UL) Tx handover on a first transmitter (Tx) and a second Tx, where, after the UL Tx handover, the first Tx is a Tx that is used and the second Tx is a Tx that is not used. The UL Tx handover is performed according to a pre-configuration or signaling indicating how to perform the UL Tx handover on the unused Tx. Further, the network device determines a band pair pattern or band pair for the user equipment to perform the UL Tx handover. And the network equipment sends MAC-CE, DCI and RRC signaling used for indicating or configuring the frequency band pair pattern or the frequency band pair. The user equipment receives the band pair pattern or band pair and transmits a UL transmission using the UL Tx switching according to the band pair pattern or band pair.

Description

Technical Field

[0001] This document generally relates to transmitter switching and band pair patterns in wireless communications. Background Art

[0002] In wireless communication, a user equipment may perform uplink (UL) transmitter (Tx) switching in at most two frequency bands. In addition, for multi-carrier operation, a user equipment (also referred to as a 2Tx user equipment) that transmits using two transmitters may transmit in at most two UL frequency bands. The two frequency bands used may only be changed by radio resource control (RRC) reconfiguration. In addition, a 2Tx user equipment may perform UL Tx switching only between two UL frequency bands. However, current UL Tx switching schemes may not allow user equipment to perform UL Tx switching on three or four frequency bands and simultaneous transmission using two transmitters to achieve more configured UL frequency bands than its simultaneous transmission capability, and / or to support dynamic Tx carrier switching across configured frequency bands. A UL Tx switching scheme that can overcome these deficiencies may be required. Summary of the invention

[0003] The present document relates to methods, systems, devices and apparatus for wireless communication. In some implementations, a method for wireless communication includes: determining, by a user equipment, to perform uplink (UL) Tx switching on a first transmitter (Tx) and a second Tx, wherein after the UL Tx switching, the first Tx is a used Tx for UL transmission, and the second Tx is an unused Tx for the UL transmission, wherein the UL Tx switching is performed according to a preconfiguration or signaling indicating how to perform the UL Tx switching on the unused Tx; and sending the UL transmission by the user equipment after the UL Tx switching.

[0004] In some other implementations, a method for wireless communication includes: determining, by a network device, a frequency band pair pattern or a frequency band pair for one or more user devices to perform uplink (UL) transmitter (Tx) switching; and sending, by the network device, a medium access control control element (MAC-CE), downlink control information (DCI), or radio resource control (RRC) signaling for indicating or configuring the frequency band pair pattern or the frequency band pair.

[0005] In some other implementations, a method for wireless communication includes: receiving, by a user equipment, a medium access control control element (MAC-CE), downlink control information (DCI), or radio resource control (RRC) signaling indicating or configuring a band pair pattern or band pair for uplink (UL) transmitter (Tx) switching; and sending, by the user equipment, a UL transmission using the UL Tx switching according to the band pair pattern or band pair.

[0006] In some other implementations, a device such as a network device is disclosed. The device may include one or more processors and one or more memories, wherein the one or more processors are configured to read computer code from the one or more memories to implement any of the above methods.

[0007] In some other implementations, a computer program product is disclosed. The computer program product may include a non-transitory computer-readable program medium having computer code stored thereon, which, when executed by one or more processors, causes the one or more processors to implement any of the above methods.

[0008] The above and other aspects and implementations thereof are described in more detail in the drawings, the description and the claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 A block diagram of an example of a wireless communication system is shown.

[0010] Figure 2 Shows Figure 1 00140 is a block diagram of an example configuration of a transceiver and antenna components of a user equipment.

[0011] Figure 3 A block diagram showing the relationship between carriers, frequency bands and cells is shown.

[0012] Figure 4 A diagram showing transmitter (Tx) switching between cells on a frequency band.

[0013] Figure 5 A flow chart of an example method of wireless communications involving uplink (UL) Tx switching is shown.

[0014] Figure 6 A diagram of an example slot frame structure for three frequency bands is shown.

[0015] Figure 7 A diagram of an example slot frame structure for four frequency bands is shown.

[0016] Figure 8 A flow chart of an example method of wireless communications related to frequency band pairs and / or frequency band pair patterns is shown.

[0017] Fig. 9 A flow chart of another example method of wireless communications related to frequency band pairs and / or frequency band pair patterns is shown.

[0018] Fig.10 A diagram of another example slotframe structure for four frequency bands is shown. DETAILED DESCRIPTION

[0019]

[0013] This specification describes various embodiments of systems, devices, apparatuses, and methods for wireless communications related to uplink (UL) transmitter (Tx) switching and band pair patterns.

[0020] Figure 1 A diagram of an example wireless communication system 100 is shown, which includes a plurality of communication nodes (or just nodes) configured to wirelessly communicate with each other. Generally, the communication nodes include at least one user device 102 and at least one network device 104. Figure 1 The example wireless communication system 100 in FIG. 1 is shown as including two user devices 102 and a device 104, the two user devices including a first user device 102(1) and a second user device 102(2). However, various other examples of the wireless communication system 100 including any of various combinations of one or more user devices 102 and / or one or more network devices 104 are possible.

[0021] Generally, a user equipment as described herein (such as user equipment 102) may include a single electronic device or apparatus capable of wireless communication over a network, or multiple electronic devices or apparatuses (e.g., a network thereof). A user equipment may include or otherwise be referred to as a user terminal, user terminal device, or user equipment (UE). In addition, the user device may be or include, but is not limited to, a mobile device (such as a mobile phone, a smart phone, a smart watch, a tablet computer, a laptop computer, a vehicle or other vessel (powered by human power, motor or engine, such as a car, airplane, train, ship or bicycle, etc., as non-limiting examples) or a fixed or stationary device (such as a desktop computer or other computing device that is not usually moved for a long time, such as an appliance, other relatively heavy devices including the Internet of Things (IoT), or computing devices used in commercial or industrial environments, etc., as non-limiting examples). In various embodiments, the user device 102 may include a transceiver circuit system 106, which is coupled to an antenna 108 to implement wireless communication with the network device 104. The transceiver circuit system 106 may also be coupled to a processor 110, which may also be coupled to a memory 112 or other storage device. The memory 112 may store therein instructions or codes, which, when read and executed by the processor 110, cause the processor 110 to implement the various methods described herein.

[0022] In addition, in general, a network device as described herein (such as network device 104) may include a single electronic device or apparatus, or multiple electronic devices or apparatuses (e.g., a network thereof), and may include one or more wireless access nodes, base stations, or other wireless network access points capable of wirelessly communicating with one or more user devices and / or one or more other network devices 104 over a network. For example, in various embodiments, network device 104 may include a 4G LTE base station, a 5G NR base station, a 5G central unit base station, a 5G distributed unit base station, a next generation Node B (gNB), an enhanced Node B (eNB), or other similar or next generation (e.g., 6G) base station. Network device 104 may include a transceiver circuit system 114 coupled to an antenna 116 to enable wireless communication with user device 102 or another network device 104, which antenna may include an antenna tower 118 in various ways. Transceiver circuit system 114 may also be coupled to one or more processors 120, which may also be coupled to a memory 122 or other storage device. The memory 122 may store therein instructions or codes that, when read and executed by the processor 120 , cause the processor 120 to implement one or more of the methods described herein.

[0023] In various embodiments, two communication nodes in the wireless system 100, such as a user device 102 and a network device 104, two user devices 102 without a network device 104, or two network devices 104 without a user device 102, can be configured to communicate wirelessly with each other in or through a mobile network and / or a wireless access network according to one or more standards and / or specifications. Typically, the standard and / or specification can define rules or procedures by which communication nodes can communicate wirelessly, and in various embodiments, these rules or procedures may include rules or procedures for communicating in a millimeter (mm) wave frequency band, and / or rules or procedures with a multi-antenna scheme and beamforming functionality. Additionally or alternatively, the standard and / or specification is one that defines wireless access technologies and / or cellular technologies, such as fourth generation (4G) long term evolution (LTE), fifth generation (5G) new wireless (NR) or new wireless unlicensed (NR-U), as non-limiting examples.

[0024] In addition, in the wireless system 100, the communication nodes are configured to wirelessly transmit signals between each other. Generally, the communication between two communication nodes in the wireless system 100 can be or include transmission or reception, and generally both are performed simultaneously, depending on the perspective of the specific node in the communication. For example, for a given communication between a first node and a second node, wherein the first node is sending a signal to the second node, and the second node is receiving a signal from the first node, the first node can be referred to as a source or sending node or device, the second node can be referred to as a destination or receiving node or device, and the communication can be considered to be sending for the first node and receiving for the second node. Of course, since the communication nodes in the wireless system 100 can send and receive signals, a single communication node can be both a sending / source node and a receiving / destination node at the same time, or switch between being a source / sending node and a destination / receiving node.

[0025] Furthermore, a specific signal may be characterized or defined as an uplink (UL) signal, a downlink (DL) signal, or a sidelink (SL) signal. An uplink signal is a signal sent from the user equipment 102 to the network device 104. A downlink signal is a signal sent from the network device 104 to the user equipment 102. A sidelink signal is a signal sent from one user equipment 102 to another user equipment 102, or a signal sent from one network device 104 to another network device 104. Furthermore, for sidelink transmission, the first / source user equipment 102 directly sends the sidelink signal to the second / destination user equipment 102 without forwarding the sidelink signal to the network device 104.

[0026] Additionally, signals transmitted between communication nodes in the system 100 may be characterized or defined as data signals or control signals. Typically, a data signal is a signal that includes or carries data, such as multimedia data (e.g., voice data and / or image data), and a control signal is a signal that carries control information that configures the communication nodes in some way to communicate with each other, or otherwise controls how the communication nodes transmit data signals to each other. Furthermore, certain signals may be defined or characterized by a combination of data / control and uplink / downlink / sidelink, including uplink control signals, uplink data signals, downlink control signals, downlink data signals, sidelink control signals, and sidelink data signals.

[0027] For at least some specifications (such as 5G NR), data signals and control signals are sent and / or carried on physical channels. In general, a physical channel corresponds to a set of time-frequency resources for transmitting signals. Different types of physical channels can be used to send different types of signals. For example, a physical data channel (or data-only channel), also referred to herein as a traffic channel, is used to send data signals, and a physical control channel (or control-only channel) is used to send control signals. Example types of traffic channels (or physical data channels) include, but are not limited to, a physical downlink shared channel (PDSCH) for transmitting downlink data signals, a physical uplink shared channel (PUSCH) for transmitting uplink data signals, and a physical sidelink shared channel (PSSCH) for transmitting sidelink data signals. In addition, example types of physical control channels include, but are not limited to, a physical downlink control channel (PDCCH) for transmitting downlink control signals, a physical uplink control channel (PUCCH) for transmitting uplink control signals, and a physical sidelink control channel (PSCCH) for transmitting sidelink control signals. As used herein for simplicity, unless otherwise specified, a particular type of physical channel is also used to refer to a signal transmitted on the particular type of physical channel, and / or a transmission on the particular type of physical channel. As an example, PDSCH refers to the physical downlink shared channel itself, a downlink data signal transmitted on the PDSCH, or a downlink data transmission. Therefore, a communication node sending or receiving a PDSCH means that the communication node is sending or receiving a signal on the PDSCH.

[0028] In addition, for at least some specifications, such as 5G NR, and / or for at least some types of control signals, the control signals sent by the communication nodes may include control information including information necessary to enable transmission of one or more data signals and / or scheduling of one or more data channels (or one or more transmissions on data channels) between the communication nodes. For example, such control information may include information necessary to correctly receive, decode, and demodulate data signals received on a physical data channel during data transmission, and / or information necessary for uplink scheduling grants that inform user equipment of resources and transport formats for uplink data transmission. In some embodiments, the control information includes downlink control information (DCI) sent from the network device 104 to the user equipment 102 in the downlink direction. In other embodiments, the control information includes uplink control information (UCI) sent from the user equipment 102 to the network device 104 in the uplink direction, or sidelink control information (SCI) sent from one user equipment 102(1) to another user equipment 102(2) in the sidelink direction.

[0029] In addition, in some embodiments, the user equipment 102 may be configured to support at least one simultaneous UL transmission mode across a frequency band pair for UL transmission. In a first simultaneous UL transmission mode (also referred to as switchedUL mode), the user equipment 102 does not support simultaneous UL transmission across frequency band pairs. Therefore, when the user equipment 102 sends an UL transmission in the first simultaneous UL transmission mode, the user equipment 102 sends across the frequency band pair without sending the UL transmission simultaneously. In addition, in a second simultaneous UL transmission mode (also referred to as dualUL mode), the user equipment 102 supports simultaneous UL transmission across frequency band pairs. Therefore, when the user equipment 102 sends an UL transmission in the second simultaneous UL transmission mode, the user equipment 102 may send the UL transmission by sending simultaneously across the frequency band pair.

[0030] In addition, for at least some embodiments, as used herein, the first and second UL simultaneous transmission modes may be referred to as or correspond to a carrier aggregation (CA) option. For example, the first simultaneous UL transmission (or switchedUL) mode may also be referred to as or correspond to a first CA option or a switchedUL CA option. The second simultaneous UL transmission (or dualUL) mode may also be referred to as or correspond to a second CA option or a dualUL CA option. Correspondingly, when the user equipment 102 operates using the switchedUL CA option, the user equipment 102 does not support and / or perform simultaneous UL transmissions across frequency band pairs. When the user equipment 102 operates using the dualUL CA option, the user equipment 102 supports and / or performs simultaneous UL transmissions across frequency band pairs.

[0031] Furthermore, in some embodiments, the user equipment 102 may report (multiple) simultaneous UL transmission modes to the network device 104. That is, the user equipment 102 may report to the network device 104 that it supports simultaneous UL transmission across frequency band pairs, that it does not support simultaneous UL transmission across frequency band pairs, or that it supports and does not support both simultaneous UL transmission across frequency band pairs. In a specific embodiment of these embodiments, the user equipment 102 may report whether it supports simultaneous UL transmission across frequency band pairs of each frequency band combination (BC). Furthermore, the network device 104 may configure simultaneous UL transmission modes (e.g., switchedUL or dualUL) for each cell group, which may be considered according to BC or frequency band pairs in an embodiment where a 2Tx user equipment supports only two frequency bands. That is, one available frequency band pair in a frequency band combination may support one simultaneous UL transmission mode.

[0032] In addition, generally as used herein, a band combination may include multiple bands (e.g., five bands). In addition, as used herein, a band group may include at most three or four bands. A given band group may be included in a band combination or as part of a band combination. And, a band combination and / or a band group may include at least one band pair, wherein the band pair includes two bands.

[0033] Figure 2 A block diagram of an example configuration of transceiver 106 and antenna 108 is shown. Specifically, transceiver 106 includes first transmitter circuit 202(1) and second transmitter circuit 202(2). Additionally, antenna 108 may include first antenna component 204(1) and second antenna component 204(2). Generally, first transmitter circuit 202(1) and first antenna component 204(1) may form a first transmitter channel or chain, and second transmitter circuit 202(2) and second antenna component 204(2) may form a second transmitter channel or chain. Figure 2 The user equipment 102 configured in the embodiment may be configured to send a first UL transmission (or a first portion of a UL transmission) using a first transmitter channel, and may be configured to send a second UL transmission (or a second portion of a UL transmission) using the first transmitter channel. In addition, as used herein, unless otherwise specified, the term "transmitter" is used to refer to a separate transmitter circuit, a separate antenna component, or a combination of a transmitter circuit and an antenna component (i.e., a transmitter channel or chain).

[0034] In addition, in various embodiments, user equipment 102 can use two transmitter channels to send on one or two frequency bands or carriers. User equipment 102 can do this in any of a variety of ways. For example, user equipment 102 can use both a first transmission channel and a second transmission channel to send on a single carrier. As another example, user equipment 102 can use a first transmission channel to send on a first carrier, and use a second transmission channel to send on a second carrier. As used herein, the terms "1Tx" and "1T" refer to sending on one carrier using one channel, and the terms "2Tx" and "2T" refer to sending on one carrier using two transmission channels.

[0035] In addition, as used herein, the phrase "UL transmission instance" refers to a specific configuration of a transmission channel for UL transmission on one or more carriers. And, as described in more detail below, the user equipment 102 can switch between UL transmission instances during the UL Tx switching operation. Table 1 below lists two example UL transmission instances, Instance 1 and Instance 2.

[0036] Example 1 1Tx on carrier 1 and 1Tx on carrier 2 Example 2 0Tx on carrier 1 and 2Tx on carrier 2

[0037] Table 1: Examples of UL transmission instances

[0038] Table 1 shows that for a first UL transmission instance (Instance 1), the user equipment 102 uses one transmission channel (1Tx) for each carrier, such as by using a first transmitter to transmit on a first carrier (Carrier 1), and using a second transmitter to transmit on a second carrier (Carrier 2) to transmit UL transmissions on two carriers. In addition, Table 1 shows that for a second UL transmission instance (Instance 2), the user equipment 102 uses two transmitters (2Tx) to transmit on the second carrier to transmit UL transmissions on only one carrier. For this second instance, the user equipment 102 does not use any transmission channel to transmit on the first carrier.

[0039] In addition, in various embodiments, the user equipment 102 may perform UL transmitter (Tx) switching to perform UL transmission. In general, the user equipment 102 may perform UL Tx switching by switching from one UL transmission instance to another UL transmission instance. In operation, the user equipment 102 may send UL transmission according to a first UL transmission instance, and then switch from the first UL transmission instance to a second UL transmission instance, and send UL transmission according to the second UL transmission instance. For illustration, using Table 1, for example, the user equipment may send UL transmission according to Instance 1, such as by using a first transmitter to send on a first carrier and using a second transmitter to send on a second carrier. Then, the user equipment 102 may switch from Instance 1 to Instance 2, and then according to Instance 2, such as by using both the first transmitter and the second transmitter to send on a second carrier to send UL transmission.

[0040] In various embodiments, such as with reference to Table 1, the type of UL Tx switching performed by the user equipment 102 may be referred to as 1Tx-2Tx switching. For 1Tx-2Tx switching, the user equipment 102 may switch from transmitting on one carrier using one transmitter to transmitting on one carrier using two transmitters, or may switch from transmitting on one channel using two transmitters to transmitting on one transmitter.

[0041] In addition, in various embodiments, the UL transmission instance may also identify the number of antenna ports corresponding to the carrier. The identification may be in the form of a mapping between the carrier and the corresponding number of antenna ports. For at least some of these embodiments, the number of antennas may depend on whether the user equipment 102 supports simultaneous transmission across frequency band pairs. Table 2 shows an example UL transmission instance when simultaneous transmission across frequency band pairs is not supported, and additionally when the user equipment 102 applies carrier aggregation including a supplementary UL (SUL) band.

[0042]

[0043] Table 2: Example of UL transmission case with antenna port number mapping where the UE does not support simultaneous transmission across frequency band pairs

[0044] In the example shown in Table 2, for the first UL transmission instance (Example 1), the user equipment 102 uses the first transmitter to transmit on the first carrier, and uses the second transmitter to transmit on the second carrier. And, based on the fact that the user equipment 102 does not support simultaneous transmission across frequency band pairs, the number of antenna ports used for UL transmission on the first carrier is 1, and the number of antenna ports used for UL transmission on the second carrier is zero (1P+0P). In addition, in the example shown in Table 2, for the second UL transmission instance (Example 2), the user equipment 102 uses both the first transmitter and the second transmitter to transmit on the second carrier. And, based on the fact that the user equipment 102 does not support simultaneous transmission across frequency band pairs, the number of antenna ports used for the two carriers can be one of two options. In the first option, the number of antenna ports used for the first carrier is 0, and the number of antenna ports used for the second carrier is 2. In the second option, the number of antenna ports used for the first carrier is 0, and the number of antenna ports used for the second carrier is 1.

[0045] Table 3 shows an example UL transmission instance when simultaneous transmission across frequency band pairs is supported.

[0046]

[0047] Table 3: Example of UL transmission instance with antenna port number mapping where the UE supports simultaneous transmission across frequency band pairs

[0048] lose

[0049] In the example shown in Table 3, for the first UL transmission instance (Instance 1), the user equipment 102 transmits on the first carrier using the first transmitter and transmits on the second carrier using the second transmitter. And, based on the user equipment 102 does support simultaneous transmission across frequency band pairs, the number of antenna ports used for UL transmission can be one of three options. In the first option, the number of antenna ports for the first carrier is 1, and the number of antenna ports for the second carrier is 0. In the second option, the number of antenna ports for the first carrier and for the second carrier is 1 each. In the third option, the number of antenna ports for the first carrier is 0, and the number of antenna ports for the second carrier is 1. In the second UL transmission instance, the user equipment 102 does not transmit on the first carrier using any transmitter, but transmits on the second carrier using two transmitters. And, based on the user equipment 102 does support simultaneous transmission across frequency band pairs, the number of antenna ports used for UL transmission can be one of two options. In the first option, the number of antenna ports for the first carrier is 0, and the number of antenna ports for the second carrier is 2. In a second option, the number of antenna ports for the first carrier is 0, and the number of antenna ports for the second carrier is 1.

[0050] As mentioned above, the user equipment 102 may perform 1Tx-2Tx UL Tx switching, in which the user equipment 102 switches between one transmitter and two transmitters for transmission on one channel. Another type of UL Tx switching may include 2Tx-2Tx switching, in which the user equipment 102 switches from transmitting on one carrier using two transmitters to transmitting on another carrier using two transmitters. Tables 4 and 5 below show examples of 2Tx-2Tx UL Tx switching.

[0051] Number of Tx chains in WID (Carrier 1 + Carrier 2) Example 1 0T+2T Example 2 2T+0T

[0052] Table 4: First example of UL transmission instance for 2Tx-2Tx switching

[0053]

[0054]

[0055] Table 5: Example of UL transmission instance combining 1Tx-2Tx switching and 2Tx-2Tx switching

[0056] Referring to Table 4, in the first example of 2Tx-2Tx UL Tx switching, in the first transmission instance (Instance 1), the user equipment 102 uses two transmitters to transmit on the second carrier, and does not use any transmitter to transmit on the first carrier. In the second transmission instance (Instance 2), the user equipment 102 uses two transmitters to transmit on the first carrier, and does not use any transmitter to transmit on the second carrier. For 2Tx-2Tx UL Tx switching, the user equipment 102 can switch from the first transmission instance to the second transmission instance, or can switch from the second transmission instance to the first transmission instance.

[0057] Referring to Table 5, the user equipment 102 may use a combination of 1Tx-2Tx switching and 2Tx-2Tx switching. For example, in Table 5, instance 1 corresponds to instance 1 in Table 2, and instance 2 and instance 3 correspond to instance 1 and instance 2 in Table 4, respectively. The user equipment 102 may perform 1Tx-2Tx switching by switching between instance 1 and instance 2 and / or between instance 1 and instance 3, and may perform 2Tx-2Tx switching by switching between instance 2 and instance 3.

[0058] And, in various embodiments, the UL transmission instance may also identify the number of antenna ports corresponding to the carrier for 2Tx-2Tx switching, such as in the form of a mapping between the carrier and the corresponding number of antenna ports, similar to Tables 2 and 3 above, which show the mapping between the carrier and the number of antenna ports for 1Tx-2Tx switching. The mapping may depend on whether the user equipment 102 supports simultaneous switching across frequency band pairs. Table 6 below shows an example UL transmission instance with a mapping of the number of antenna ports for 2Tx-2Tx switching, where the user equipment 102 does not support simultaneous transmission across frequency band pairs. Table 7 below shows an example UL transmission instance with a mapping of the number of antenna ports for 2Tx-2Tx switching, where the user equipment 102 supports simultaneous transmission across frequency band pairs.

[0059]

[0060] Table 6: Example of UL transmission case with antenna port number mapping for 2Tx-2Tx switching where the UE does not support simultaneous transmission across frequency band pairs

[0061]

[0062]

[0063] Table 7: Example of UL transmission case with antenna port number mapping for combination of 1Tx-2Tx switching and 2Tx-2Tx switching where UE supports simultaneous transmission across frequency band pairs

[0064] In addition, in various embodiments, the user equipment 102 may perform 1Tx-2Tx and / or 2Tx-2Tx UL Tx switching with respect to a frequency band. For example, one carrier may be on one frequency band (e.g., frequency band A), and two carriers (such as two adjacent carriers) may be on another frequency band (e.g., frequency band B). For at least some of these embodiments, the frequency band with one carrier may be a supplementary UL (SUL) frequency band, and the frequency band with two adjacent carriers may be a non-SUL frequency band or a normal uplink (NUL) frequency band. For at least some of these examples, the user equipment 102 may perform UL Tx switching between any two or three of the following examples for the first frequency band and the second frequency band (i.e., frequency band A+frequency band B): Example 1: 1T+1T; Example 2: 0T+2T; Example 3: 2T+0T.

[0065] In addition, for embodiments in which the user equipment 102 performs UL Tx switching with respect to a frequency band, the UL transmission instance may identify the number of antenna ports for the carriers of the frequency band, similar to Tables 2, 3, 6, and 7 above. Tables 8-11 show various UL transmission instances with antenna port number mappings for two frequency bands including three carriers, wherein the first frequency band (Band A) includes one carrier and the second frequency band (Band B) includes two adjacent carriers. Table 8 shows an example UL transmission instance for 1Tx-2Tx UL Tx switching, wherein the user equipment 102 does not support simultaneous transmission across frequency band pairs. Table 9 shows an example UL transmission instance for 1Tx-2Tx UL Tx switching, wherein the user equipment 102 supports simultaneous transmission across frequency band pairs. Table 10 shows an example UL transmission instance for 2Tx-2Tx UL Tx switching, wherein the user equipment 102 does not support simultaneous transmission across frequency band pairs. Table 11 shows an example UL transmission instance for 2Tx-2Tx UL Tx switching, wherein the user equipment 102 supports simultaneous transmission across frequency band pairs.

[0066]

[0067] Table 8: Example UL transmission instance with antenna port number mapping for 1Tx-2Tx switching where the UE does not support simultaneous transmission across frequency band pairs

[0068]

[0069] Table 9: Example UL transmission instance with antenna port number mapping for 1Tx-2Tx switching where the UE supports simultaneous transmission across frequency band pairs

[0070]

[0071] Table 10: Example UL transmission instance with antenna port number mapping for 2Tx-2Tx switching where the UE does not support simultaneous transmission across frequency band pairs

[0072]

[0073] Table 11: Example UL transmission instance with antenna port number mapping for 2Tx-2Tx switching where the UE supports simultaneous transmission across frequency band pairs

[0074] And, in various embodiments, the user equipment 102 may be configured with three frequency bands to perform UL Tx switching for the three frequency bands and send UL transmissions within the three frequency bands. The three frequency bands may include a first frequency band (frequency band A), a second frequency band (frequency band B), and a third frequency band (frequency band C). For at least some of these embodiments, the user equipment 102 may dynamically select any two of the three frequency bands to perform UL Tx switching. In various of these embodiments, the three frequency bands may include various combinations of SUL frequency bands and conventional frequency bands or non-SUL (NUL) frequency bands, and examples of two scenarios are as follows.

[0075] In the first scenario (Scenario 1): Band A is a SUL band or a non-SUL band, Band B is a non-SUL band, and Band C is a SUL band or a non-SUL band. That is, Band C is similar to Band A. In one example of Scenario 1, Band A includes a first carrier (Carrier 1), Band B includes a second carrier (Carrier 2), and Band C includes a third carrier (Carrier 3). In a second example of Scenario 1, Band A includes Carrier 1, Band B includes Carrier 2 and Carrier 3, and Band C includes a fourth carrier (Carrier 4).

[0076] In the second scenario (Scenario 2), band A is a SUL band or a non-SUL band, band B is a non-SUL band, and band C is a non-SUL band. That is, band C is similar to band B. In one example of Scenario 2, band A includes carrier 1, band B includes carrier 2, and band C includes carrier 3 and carrier 4. In a second example of Scenario 2, band A includes carrier 1, band B includes carrier 2 and carrier 3, and band C includes carrier 4 and a fifth carrier (carrier 5).

[0077] In addition, in various other embodiments, the user equipment 102 may be configured with four frequency bands to perform UL Tx switching for the four frequency bands and send UL transmissions in the four frequency bands, the four frequency bands including a first frequency band (frequency band A), a second frequency band (frequency band B), a third frequency band (frequency band C), and a fourth frequency band (frequency band D). Similar to the three-band configuration, the user equipment 102 may dynamically select any two of the four frequency bands to perform UL Tx switching. In various of these embodiments, the four frequency bands may include various combinations of SUL frequency bands and NUL frequency bands, and examples of two scenarios are as follows.

[0078] In the first scenario (Scenario 1), band A is a SUL band or a non-SUL band, band B is a non-SUL band, and band C is a SUL band or a non-SUL band. That is, band C is similar to band A. In the first example of scenario 1, the band includes a first carrier (carrier 1), band B includes a second carrier (carrier 2), band C includes a third carrier (carrier 3), and band D includes a fourth carrier (carrier 4). In the second example of scenario 1, band A includes carrier 1, band B includes carrier 2, band C includes carrier 3, and band D includes carrier 4 and a fifth carrier (carrier 5). In the third example of scenario 1, band A includes carrier 1, band B includes carrier 2 and carrier 3, band C includes carrier 4, and band D includes carrier 5. In the fourth example of scenario 1, band A includes carrier 1, band B includes carrier 2 and carrier 3, band C includes carrier 4, and band D includes carrier 5 and a sixth carrier (carrier 6).

[0079] In the second scenario (Scenario 2), band A is a SUL band or a non-SUL band, band B is a non-SUL band, and band C is a non-SUL band. That is, band C is similar to band B. In a first example of scenario 2, band A includes carrier 1, band B includes carrier 2, band C includes carrier 3 and carrier 4, and band D includes carrier 5. In a second example of scenario 2, band A includes carrier 1, band B includes carrier 2, band C includes carrier 3 and carrier 4, and band D includes carrier 5 and carrier 6. In a third example of scenario 2, band A includes carrier 1, band B includes carrier 2 and carrier 3, band C includes carrier 4 and carrier 5, and band D includes carrier 6. In a fourth example of scenario 2, band A includes carrier 1, band B includes carrier 2 and carrier 3, band C includes carrier 4 and carrier 5, and band D includes carrier 6 and carrier 7.

[0080] And, for an embodiment in which the user equipment 102 performs dynamic Tx carrier switching across the configured frequency bands, at least one of the following options. In the first option, the user equipment 102 can perform dynamic Tx carrier switching across all supported UL transmission instances supported by the UE and based on UL scheduling, i.e., via UL grant and / or RRC configuration for UL transmission. In the second option, the network device 104 can indicate two frequency bands from the configured frequency bands (3 or 4 frequency bands) via DCI or a medium access control (MAC) control element (CE). In the third option, the user equipment 102 can select an anchor frequency band among the configured frequency bands (3 or 4 frequency bands) and can perform dynamic Tx carrier switching only from the anchor frequency band to the non-anchor frequency band and / or from the non-anchor frequency band to the anchor frequency band.

[0081] Table 12 shows an example set of ten UL transmission instances for four frequency bands with antenna port number mapping. The second column in Table 12 indicates the number of antenna ports when the user equipment 102 does not support simultaneous transmission across multiple carriers, and the third column indicates the number of antenna ports when the user equipment 102 supports simultaneous transmission across up to two carriers.

[0082]

[0083]

[0084] Table 12: Example UL transmission instances for 4 frequency bands with antenna port number mapping, where the UE does not support simultaneous transmission across multiple carriers and supports simultaneous transmission across at most two carriers

[0085] For embodiments in which the user equipment 102 supports all UL transmission instances according to the first option above (e.g., all ten UL transmission instances in Table 12), the user equipment 102 can switch between any two UL transmission instances without any additional restrictions. For example, assume that the current transmission state of the user equipment 102 is to transmit on two carriers on two frequency bands using one transmitter to transmit on each frequency band, and assume that the user equipment 102 is switching two different carriers on two different frequency bands, but still using one transmitter to transmit on each frequency band. For example, the user equipment 102 can switch from instance 1 to instance 8. Corresponding to instance 1 and instance 8 in Table 12, the user equipment 102 can send a first transmission (instance 1) on carrier 1 in cell 1 and carrier 2 in cell 2, and then switch and send a second transmission (instance 8) on carrier 3 in cell 3 and carrier 4 in cell 4. Correspondingly, Figure 3 A one-to-one relationship between four frequency bands, four carriers, and four cells is shown.

[0086] And, for at least some embodiments in conjunction with the second option above, where the network device 104 indicates a band pair from the configured bands (3 or 4 bands), there may be no additional restrictions on which band pairs are selected. For example, assume that there are six band pairs corresponding to a band combination with four bands. After the network device 104 selects the band pairs and indicates them to the user device 102, the user device 102 may perform a UL Tx switch to switch to the band pair indicated by the network device 102. Any subsequent UL Tx switch may be within the indicated band pair until the next indication from the network device 104. Figure 4 Shows an example. Figure 4 , the currently available frequency band pairs may include frequency band 1 and frequency band 2. Any UL Tx switching is performed within frequency band 1 and frequency band 2 (e.g., between cell 1 on frequency band 1 and cell 2 on frequency band 2). On the network side, the network device 104 may select a frequency band pair out of the four frequency bands. For example, the network device 104 may select frequency band 3 and frequency band 4, and indicate the selected frequency band 3 and frequency band 4 to the user equipment 102, such as through a DCI or a MAC CE. In response to the indication, the user equipment 102 may switch from frequency band 1 and frequency band 2 to frequency band 3 and frequency band 4. Thereafter, any switching performed by the user equipment 102 is within frequency band 3 and frequency band 4, such as between cell 3 on frequency band 3 and cell 4 on frequency band 4, until the next indication is received from the network device 104.

[0087] Various embodiments related to performing UL Tx switching for unused transmitters and / or methods of reducing the number of times indicating band pair switching when one or more time division duplex (TDD) bands exist within a configured number (e.g., three or four) of bands are described below.

[0088] Figure 5 1 is a flow chart of an example method 500 for wireless communication involving UL Tx switching. At block 502, the user equipment 102 determines to perform uplink (UL) Tx switching on a first transmitter (Tx) and a second Tx, wherein after the UL Tx switching, the first Tx is a used Tx for UL transmission and the second Tx is an unused Tx for the UL transmission. The UL Tx switching is performed according to a preconfiguration or signaling indicating how to perform the UL Tx switching on the unused Tx. At block 504, the user equipment uses the UL Tx switching to send the UL transmission.

[0089] Example 1

[0090] In more detail, in some embodiments of the method 500, the user equipment 102 may perform a previous UL transmission under a first transmission instance. Then, the user equipment 102 may perform a UL Tx switching instance to switch from the first transmission instance to the second transmission instance. After performing the UL Tx switching instance, the user equipment 102 may perform UL transmission under the second transmission instance. In the transmission instance, each of the two transmitters of the user equipment 102 may be a used transmitter or an unused transmitter. During the transmission instance, when the transmitter transmits on the antenna port, the transmitter is a used transmitter. At the same time, during the transmission instance, when the transmitter does not transmit on the antenna port, the transmitter is an unused transmitter. Therefore, after the user equipment 102 performs the UL Tx switching instance and is in the second transmission instance, in the switchedUL or dualUL, one of the transmitters of the user equipment 102 may be an unused transmitter. For at least some embodiments, including embodiments in which the user equipment 102 is capable of performing dynamic UL Tx switching across all supported UL transmission instances and based on a scheduled UL, for example via a UL grant and / or a radio resource control (RRC) configuration for UL transmissions, the user equipment 102 can determine how to configure, move, switch, or operate an unused transmitter during UL Tx switching based on a preconfiguration (or predefined rules) or signaling indicating how to perform UL Tx switching for the unused transmitter.

[0091] In addition, in various embodiments, the user equipment 102 performs UL Tx switching according to a UL Tx switching scheme spanning up to three or four frequency bands and / or with a restriction that it can perform up to 2 Tx simultaneous transmissions. For example, it is assumed that the user equipment 102 performs UL Tx switching across three frequency bands including frequency band A, frequency band B, and frequency band C. Correspondingly, the user equipment 102 can perform UL Tx switching between six possible UL transmission instances, as shown in Table 13 below.

[0092]

[0093]

[0094] Table 13: UL transmission examples for a scenario with up to 2 Txs on each band

[0095] As shown in Table 13, for UL transmission instance 1-1, the user equipment 102 uses the first transmitter to transmit on frequency band A, uses the second transmitter to transmit on frequency band B, and does not use any transmitter to transmit on frequency band C. For UL transmission instance 1-2, the user equipment 102 uses the first transmitter to transmit on frequency band B, uses the second transmitter to transmit on frequency band C, and does not use any transmitter to transmit on frequency band A, etc. Correspondingly, for each UL transmission instance, the two transmitters of the user equipment 102 are allocated to transmit on only one frequency band (i.e., two transmitters on one frequency band, such as in transmission instances 2-1, 2-2, and 2-3) or on two frequency bands (i.e., one transmitter on each of the two frequency bands, such as in transmission instances 1-1, 1-2, and 1-3).

[0096] Example 1-1:

[0097] In addition, in various embodiments, the maximum number of transmitters that can be used on a given frequency band can be specified and / or limited. For example, a given frequency band can be limited to only one or at most two transmitters transmitting on it.

[0098] In one example, it is assumed that the transmitter restriction configuration of the three frequency bands is: 1T-1T-2T, that is, the maximum number of Tx supported on the three frequency bands (bands A, B and C) is 1Tx, 1Tx and 2Tx respectively, and there is one carrier on each frequency band. In other embodiments, one or more frequency bands may also be supported by two or more carriers. That is, both band A and band B are limited to having at most one transmitter, and band C is limited to having at most two transmitters. The transmission switching option parameter, i.e., uplinkTxSwitchingOption, can be set to "switchedUL", which can also be named CA option 1 as before, which means that the user equipment 102 does not support simultaneous transmission between or across two frequency bands. Under the "switchedUL" operation, the user equipment 102 can perform UL transmission on one of the frequency bands A, B or C. In this case, for at least some of the entries in Table 13, the possible combinations of the number of antenna ports for UL transmission are listed in Tables 14-17 below. In addition, in various embodiments, the switched UL may be considered to include or exclude the conventional CA mode. The conventional CA mode means that the maximum number of Tx supported on the two bands A+B is 1Tx and 1Tx, and at least one of one port (1P) on band A, 1P on band B, and 1P+1P on the band pair A+B may be supported.

[0099]

[0100] Table 14: Example mapping of three frequency bands with 1T-1T-2T in Switched UL mode

[0101]

[0102] Table 15: Example mapping of three frequency bands with 1T-1T-2T in Switched UL mode

[0103]

[0104] Table 16: Example mapping of three frequency bands with 1T-1T-2T in Switched UL mode

[0105]

[0106] Table 17: Example mapping of three frequency bands with 1T-1T-2T in Switched UL mode

[0107] For example, for at least some of the entries in Tables 14-17, Band A is a frequency division duplex (FDD) band, while Band B and Band C are time division duplex (TDD) bands, respectively. To further illustrate, Figure 6 A time slot frame structure diagram showing ten time slots of three frequency bands A, B and C is shown. Each time slot is designed to represent "D" for downlink, "U" for uplink, or "S" for special. Each "D" represents a downlink time slot designated or configured for one or more DL transmissions, and each "U" represents an uplink time slot designated or configured for one or more UL transmissions. At the same time, each "S" represents a "special" time slot that partially includes D symbols and partially includes U symbols. In addition, the S time slot is designated or configured for one or more DL transmissions on the D symbol, and is designated or configured for one or more UL transmissions on the U symbol.

[0108] Specific reference Figure 6 In the example of, the frame structures for bands C and B are: "SUDDSUUDDD" and "DDDDDDDSUU", respectively. In addition, for at least some embodiments, the frame structure uses a radio frame with a subcarrier spacing (SCS) of 15kHz. In addition, for at least some embodiments, the switching period is reported for each band pair A+B, band pair B+C, and band pair A+C, respectively. The switching periods of the three band pairs may be the same value as each other, or different values ​​from each other. For example, two switching periods may be the same, the third switching period may be different from the other two switching periods, all three switching periods may be the same as each other, or all three switching periods may be different from each other.

[0109] With particular reference to Table 14, the transmission instances provide unique operating states for 1-port transmission on each frequency band. Accordingly, when switching between the transmission instances in Table 14, no ambiguity problem occurs. However, when switching between the transmission instances in Table 14, the user equipment 102 may use an additional or undesirable number of switching cycles. For illustration, with reference to Figure 6 , the user equipment 102 may perform 1-port UL transmission on band C at time slot 6, then on band A at time slot 7, and then on band B at time slot 8. According to Table 14, the user equipment 102 may switch 1Tx on band C to band A to support 1-port transmission on band A (i.e., from instance 2-3 to instance 1-3). Then, the user equipment 102 may switch 1Tx on band A to band B to support 1-port transmission on band B (i.e., from instance 1-3 to instance 1-2).

[0110] In contrast to the transmission examples in Table 14, the transmission examples in Tables 15-17 provide more than one operating state for 1-port transmission on some specific frequency bands or all frequency bands. In these cases, ambiguity issues may arise. For illustration, use Figure 6 In the slot frame structure in FIG. 1 , the user equipment 102 may perform a 1-port UL transmission on frequency band C at time slot 6, then on frequency band A at time slot 7, and then on frequency band B at time slot 8. Figure 6Taking the transmission example in Table 15 of the frame structure in as an example, when the user equipment 102 performs the previous UL transmission on frequency band C at time slot 6 in transmission example 2-3, and then performs 1 port transmission on frequency band A, an ambiguity problem may occur. Since the user equipment 102 configured with switchedUL, supporting or not supporting the conventional CA mode may not know whether it should switch from transmission example 2-3 to transmission example 1-3 or transmission example 1-1 to transmit on frequency band A at time slot 7 based on Table 14 alone, an ambiguity problem may occur because both transmission example 1-3 and transmission example 1-1 provide 1Tx on frequency band A. In transmission example 2-3, before switching, the user equipment 102 has its first and second transmitters (2Tx) on frequency band C, corresponding to the 0T+0T+2T configuration of transmission example 2-3. In the first example, it is assumed that the user equipment 102 switches to transmission example 1-3. In this way, the user equipment 102 can finally perform two switching steps because it must transmit on frequency band B at time slot 8. In more detail, according to the first switching step from transmission instance 2-3 to transmission instance 1-3, the first transmitter (1Tx) on frequency band C can be switched to frequency band A, and the second transmitter (1Tx) can still be on frequency band C after the switching. In addition, in transmission instance 1-3, the user equipment 102 can have a port configuration of 1P+0P+0P. Correspondingly, when transmitting on frequency band A at time slot 7, the first transmitter is a used transmitter because it transmits on a port on frequency band A, and the second transmitter is a non-used transmitter because it does not transmit on any port on frequency band C, corresponding to the 1P+0P+0P port configuration associated with transmission instance 1-3. Then, in order for the user equipment 102 to transmit on frequency band B at time slot 8, the user equipment 102 can perform a second switching step to switch from transmission instance 1-3 to transmission instance 1-1. In this way, the second transmitter on band C can be switched to band B, so that the two transmitters of the user equipment 102 with transmitter configuration 1Tx+1Tx are located on band A and band B. For this switching case with two steps, the user equipment 102 performs two UL Tx switching instances within two switching cycles, including a first switching cycle of band pair A+C (i.e., the user equipment 102 switches the first transmitter from band C to band A) and a second switching cycle of band pair B+C (i.e., the user equipment 102 switches one transmitter from band C to band B).

[0111] Still refer to Table 15 and Figure 6In the second example, the user equipment 102 may switch directly from the transmission instance 2-3 to the transmission instance 1-1 (i.e., without first switching to the transmission instance 1-3). When the user equipment 102 switches from the transmission instance 2-3 to the transmission instance 1-1, the user equipment 102 may use only one switching instance with one switching cycle so as to be configured to cause the first transmitter to transmit on the frequency band A on the time slot 7 and cause the second transmitter to transmit on the frequency band B on the time slot 8. In particular, when switching from the transmission instance 2-3 to the transmission instance 1-1, the two transmitters (2Tx) of the user equipment 102 on the frequency band C may switch to 1Tx on the frequency band A and 1Tx on the frequency band B. As a result, the user equipment 102 may complete the switching of the UL transmission on the time slots 7 and 8 by performing only one UL Tx switching instance within one switching cycle. For at least some embodiments, the switching period of one switching instance may be the maximum of a first switching period of the band pair A+C (e.g., for the first transmitter switching from band C to band A) and a second switching period of the band pair B+C (e.g., for the second transmitter switching from band C to band B). In addition, in the transmission instance 1-1 on time slot 7, the user equipment 102 may have a port configuration of 1P+0P+0P, such that the first transmitter is a transmitter used on band A, and the second transmitter is a transmitter not used on band B. Then, on time slot 8, the user equipment 102, still in the transmission instance 1-1, may have a port configuration of 0P+1P+0P, such that the first transmitter is a transmitter not used on band A, and the second transmitter is a transmitter used on band B.

[0112] For embodiments where the wireless access node 104 indicates two frequency bands (or frequency band pairs) of a specific configured number of frequency bands (e.g., three or four), and the user equipment 102 can perform dynamic Tx switching between the indicated frequency bands, similar switching can also be performed. For such embodiments, the user equipment 102 can use one Tx switching instance with one switching cycle (i.e., from frequency band pair A+C or B+C to frequency band pair A+B) to switch two transmitters (2Tx) on frequency band C to a 1Tx+1Tx configuration on frequency band A and frequency band B. For such embodiments, performing a switching cycle involving one switching cycle of multiple frequency band pairs, such as switching from a previous frequency band pair A+C or B+C to a target frequency band pair A+B as shown in the figure, can be or can be determined by or based on one of the following:

[0113] (1) The switching period of the previous band pair;

[0114] (2) Switching period of the target frequency band pair;

[0115] (3) the larger of the switching period of the previous frequency band pair and the switching period of the target frequency band pair;

[0116] (4) a single value or multiple values ​​for different frequency band pairs for different handover instances reported by the user equipment 102;

[0117] (5) The maximum value of the switching period of a previous band pair (e.g., band pair A+C in the above example) and the switching period of a second previous band pair (e.g., band pair B+C in the above example), for example in a switching instance from 2Tx on one band (e.g., band C) to 1Tx+1Tx on the other two bands (e.g., band A and band B).

[0118] In order to solve the above ambiguity problem (ie, to enable the user equipment 102 to operate without ambiguity), the user equipment 102 may operate according to one of the following methods.

[0119] In the first method (method 1), the user equipment 102 performs UL Tx switching according to a preconfigured or predefined rule (or default behavior). In the first example of method 1, the default behavior is to keep the unused Tx in the previous frequency band during the initial or first switching period. Then, the user equipment 102 can switch the unused Tx to a different frequency band during another or second switching period. For illustration, also refer to Figure 6 Using the example above, on time slots 6-8, the user equipment 102 will transmit on band C on time slot 6, then on band A on time slot 7, and then on band B on time slot 8, as previously described. To this end, after transmitting on time slot 6, the user equipment 102 may move one transmitter on band C to band A in order to transmit on time slot 7. According to a first option, during a first switching cycle, the user equipment 102 moves the used transmitter from band C to band A so that the used transmitter can transmit on band A on time slot 7. During the first switching cycle, the user equipment 102 keeps the unused transmitter on band C according to a first example of a predetermined rule or default behavior (method 1). According to Tables 14-17 above, during the first switching cycle, the user equipment 102 switches from transmission instances 2-3 to transmission instances 1-3. Then, during a second switching cycle, the user equipment 102 moves the unused transmitter from band C to band B for UL transmission on band B on time slot 8. According to Tables 14-17 above, during the second switching cycle, the user equipment 102 moves from the transmission instance 1-3 to the transmission instance 1-1.

[0120] In the second example of method 1, the default behavior is to move the unused Tx from the previous frequency band to a third or different frequency band during the same switching period in which the used Tx moves from the previous frequency band to the second frequency band or to the frequency band where the previous transmission is located. In a specific embodiment of the second method, if one or more downlink time slots or symbols on the previous frequency band follow the time slot in which the user equipment 102 performs UL transmission on the previous frequency band, the user equipment 102 moves the unused Tx from the previous frequency band to the third frequency band. In other embodiments, if only the third frequency band and the second frequency band that is not the previous frequency band (or at most two frequency bands within three or more frequency bands) have one or more uplink time slots or symbols after the time slot in which the user equipment 102 performs UL transmission on the previous frequency band, the user equipment 102 moves the unused Tx from the previous frequency band to the third frequency band. For example, referring to Figure 6 , the user equipment 102 performs UL transmission on frequency band C in time slot 6. Further, as Figure 6 As shown, the time slots or symbols after time slot 6 (i.e., time slots 7, 8, and 9) are downlink time slots. In time slot 7, the transmitter that transmits on frequency band A is the used transmitter, and the transmitter that does not transmit on frequency band A is the unused transmitter. According to the second example of method 1, in the same switching cycle in which the user equipment 102 moves the used transmitter from frequency band C to frequency band A, the user equipment 102 moves the unused transmitter from frequency band C to frequency band B. In this way, according to the second example, the user equipment 102 uses only one switching cycle to switch the first transmitter from frequency band C to frequency band A, and switches the second transmitter from frequency band C to frequency band B. According to Tables 14-17, the user equipment 102 can switch the direction from transmission instance 2-3 to transmission instance 1-1 using only one switching cycle.

[0121] In the second method (Method 2), the user equipment 102 may use additional signaling to indicate how to perform UL Tx switching for the unused transmitter. The signaling may indicate one of two possible ways to perform the switching.

[0122] In a first example of method 2, the user equipment 102 may use radio resource control (RRC) signaling to configure one of two possible ways to perform switching. In a specific embodiment, for each dynamic UL Tx switch involving unused Tx, the user equipment 102 may perform switching according to the manner indicated by the signaling. In various embodiments, RRC signaling may be configured for different switching instances involving a certain number (e.g., three or four) of frequency bands, and a specific maximum number of supported Tx chains for different frequency bands. For example, referring to Tables 14-17, candidate values ​​for RRC signaling may include: {1Tx+1Tx on bands A+C, 1Tx+1Tx on bands A+B}. In other embodiments, RRC signaling may be configured for all scenarios with a specific number (e.g., 3 or 4) of frequency bands with different supported maximum Tx chains. That is, candidate values ​​for RRC signaling may include: {unused Tx on the previous band, unused Tx switched to the third band}. In various embodiments, the RRC parameter may be set to indicate that it is configured or not configured to indicate both of these modes.

[0123] In a second example of method 2, the user equipment 102 may use downlink control information (DCI) or a medium access control control element (MAC-CE) to indicate one of two possible ways to perform the switch. That is, for each dynamic UL Tx switch involving an unused Tx, the DCI or MAC-CE may indicate the way to perform the switch, and the way to perform the switch may be different depending on the use of the dynamic indication by the DCI or MAC-CE. The second example of method 2 is similar to using DCI to indicate the band pair to which 2Tx can be switched, such as when switching from one band pair to another band pair. One advantage may be that allowing different switching methods may allow the network to reduce the number of switching cycles depending on the sequence of UL transmissions assigned to the user equipment.

[0124] Therefore, by using preconfiguration, predetermined rules, default behavior or additional signaling indication, if the unused Tx can be switched to the third frequency band, the total number of switching cycles can be reduced, including the case where a downlink time slot / symbol on the previous frequency band follows a time slot in which UL transmission is performed on the previous frequency band.

[0125] Additionally or alternatively, for UL Tx switching involving the transmission instances in Table 15, a similar ambiguity problem may occur when a 1-port transmission is to be transmitted on frequency band B, and the user equipment 102 performs a previous transmission using transmission instance 2-3. When the user equipment 102 does not support simultaneous transmission on two frequency bands, the user equipment 102 may not know whether it should switch from transmission instance 2-3 to transmission instance 1-2 or transmission instance 1-1. When switching between transmission instances in Table 16, the ambiguity may be even more complex because the ambiguity may occur in 1-port transmissions in all frequency bands A, B, C. To avoid the ambiguity problem, the user equipment 102 may use predefined rules or default behaviors, or additional signaling indications, as described above.

[0126] Additionally or alternatively, in view of the transmission examples in Table 17, it is assumed that the transmission instance 1-1 is considered or regarded as including all possible antenna ports for UL transmission of a normal carrier aggregation (CA) instance. When the user equipment 102 performs UL Tx switching from another transmission instance to the transmission instance 1-1, the user equipment 102 may switch 1Tx or 2Tx to one band of the band pair A+B or both bands of the band pair A+B. For example, the user equipment 102 may switch 1Tx on band C to band A when switching from instance 1-2 to instance 1-1, switch 1Tx on band C to band B when switching from instance 1-3 to instance 1-1, and switch 2Tx on band C to 1Tx on band A and 1Tx on band B when switching from instance 2-3 to instance 1-1. Such a switching operation of the transmission instance 1-1 may be considered as a fallback to the normal CA instance or the transmission instance 1-1.

[0127] For at least some of these embodiments involving switching between transmission instances in at least Tables 15, 16, and 17, there may be no switching period within the frequency band pair A+B (i.e., for the frequency band pair, the switching period=0us). In addition, in various embodiments of these embodiments, the user equipment 102 may support simultaneous transmission on the frequency band pair A+B.

[0128] Embodiment 1-2:

[0129] In other embodiments, the user equipment 102 may transmit on three frequency bands, with a maximum number of transmitters per frequency band of 1T-1T-1T, one carrier per frequency band. That is, all frequency bands are restricted to having at most one transmission chain. When the user equipment 102 operates in switchUL mode (i.e., the user equipment 102 does not support simultaneous transmission on two frequency bands), the user equipment 102 may perform UL transmissions on one of the three frequency bands (band A, B, or C). In these cases, some examples of possible combinations of the number of antenna ports for UL transmission are provided in Tables 18-21 below.

[0130]

[0131] Table 18: Example mapping of three frequency bands with 1T-1T-1T in Switched UL mode

[0132]

[0133]

[0134] Table 19: Example mapping of three frequency bands with 1T-1T-1T in Switched UL mode

[0135]

[0136] Table 20: Example mapping of three frequency bands with 1T-1T-1T in Switched UL mode

[0137]

[0138] Table 21: Example mapping of three frequency bands with 1T-1T-1T in Switched UL mode with conventional CA

[0139] For some embodiments involving UL Tx switching using the transmission examples in Tables 18-21, Band A is an FDD band, and Band B and Band C are TDD bands. Figure 6 The slotted frame structure of Tables 18-21 describes an example UL Tx switching between the transmission instances. As previously described, in the example slotted frame structure, bands C and B may have the following slot designations, respectively: "SUDDSUUDDD" and "DDDDDDDSUU". For at least some of these embodiments, the radio frame may have a subcarrier spacing (SCS) of 15kHz. Additionally or alternatively, a switching period is reported for each of the band pairs A+B, B+C, and A+C. Any two switching periods of these band pairs may be the same or different from each other.

[0140] In addition, similar to the UL Tx switching according to the transmission examples in Tables 14-17, the UL Tx switching according to the transmission examples in Table 18 may not cause any ambiguity problem for the unused transmitter. However, when performing UL Tx switching between the transmission examples in Tables 19-21, ambiguity problems may occur.

[0141] Referring to Table 19, as an example, when, for example, the user equipment 102 is to perform a 1-port transmission on band B, and the user equipment 102 performs a previous transmission using transmission instance 1-3 to transmit on band C, an ambiguity problem may occur. Because the user equipment 102 may not know whether to switch to transmission instance 1-1 or transmission instance 1-2 (because both transmission instances provide transmission on band B), an ambiguity problem may occur. In a first approach, the user equipment 102 may decide to switch from transmission instance 1-3 to transmission instance 1-2. However, transmission instance 1-2 does not provide transmission on band A. Therefore, if the user equipment 102 switches to transmission instance 1-2, and in the case where the user equipment 102 must transmit on band B and band A in one or more next time slots or symbols, the user equipment 102 may perform two switching instances in two switching cycles. In more detail, when transmitting on band C in transmission instance 1-3, the first transmitter on band A is not used, and the second transmitter on band C is used. Then, in the first switching instance of the transmission instance 1-2, the user equipment 102 may switch the first unused Tx on band A to band B, while the second transmitter remains on band C. In the transmission instance 1-2, the first transmitter is a used transmitter on band B, and the second transmitter is an unused transmitter on band C. Then, the user equipment 102 may perform a second switching from the transmission instance 1-2 to the transmission instance 1-1 by switching the second unused transmitter on band C to band A. After the second switching instance, the user equipment 102 may have a transmitter configuration 1Tx+1Tx on band A and band B. In this way, the user equipment 102 performs two UL Tx switching instances in two switching cycles (i.e., the first switching cycle of the band pair A+B and the second switching cycle of the band pair A+C).

[0142] In the second way, the user equipment 102 may decide to switch directly from the transmission instance 1-3 to the transmission instance 1-1 without first switching to the transmission instance 1-2. In this way, the user equipment 102 may perform only one switching step in one switching cycle, which includes switching 1Tx on band C to 1Tx on band B, while leaving the other 1Tx on band A. After the switching, the user equipment 102 has a transmitter configuration of 1Tx+1Tx on the band pair A+B.

[0143] For this case, the user equipment 102 may use pre-configuration, pre-defined rules, default behavior, and / or additional signaling instructions that indicate to the user equipment 102 how to perform handover for the unused transmitters.

[0144] Embodiment 1-3:

[0145] In other embodiments, the user equipment 102 may perform UL transmission on four frequency bands including frequency bands A, B, C, and D. Table 22 below provides ten exemplary transmission instances, provided that the number of Txs per frequency band may be at most two.

[0146]

[0147]

[0148] Table 22: Example transmission instances for four frequency bands

[0149] In one embodiment, for four frequency bands, the number of Tx for each frequency band is 1T-1T-1T-1T, with one carrier on each frequency band. That is, all frequency bands are restricted to have at most one transmission chain. The transmission switching option parameter, i.e., uplinkTxSwitchingOption, can be set to "switchUL". When operating in switchUL mode, the user equipment 102 can perform uplink transmission on one of the frequency bands A, B, C, or D. In this case, for some entries in Table 22, exemplary possible combinations of the number of antenna ports for uplink transmission are listed in Tables 23-26 below.

[0150]

[0151] Table 23: Example mapping of four frequency bands with 1T-1T-1T-1T in Switched UL mode

[0152]

[0153] Table 24: Example mapping of four frequency bands with 1T-1T-1T-1T in Switched UL mode

[0154]

[0155] Table 25: Example mapping of four frequency bands with 1T-1T-1T-1T in Switched UL mode

[0156]

[0157] Table 26: Example mapping of four frequency bands with 1T-1T-1T-1T in Switched UL mode

[0158] Example UL Tx switching across four bands using the transmission examples in Tables 23-26 is now described. In some examples, bands A and C are FDD bands, while bands B and D are TDD bands. To supplement UL Tx switching, reference is made to an example slot frame structure showing Figure 7 An example is described, where the example slot frame structure includes ten time slots on four frequency bands A, B, C, and D. The slot designations of the time slots on bands D and B are: "SUDDSUUDDD" and "DDDDDDDSUU", respectively. For at least some embodiments, the wireless frame may have a subcarrier spacing (SCS) of 15 kHz. Additionally or alternatively, a switching period may be reported for each of band pair A+B, band pair B+C, band pair C+D, and band pair A+D. In any of the various embodiments, any two switching periods may be the same or different from each other, having the same or different values, respectively. In addition, when switching is performed according to the transmission examples in Table 25, additional switching periods may be reported for band pair A+C and band pair B+D.

[0159] Referring to Table 23, for the transmission examples in Table 23, no ambiguity problem occurs due to their unique operating states for 1-port transmission on each band. However, switching between these transmission examples may generate an additional or undesirable number of switching cycles. For reference Figure 7 In other words, the user equipment 102 may perform 1-port transmission on band D at time slot 6, then perform on band C at time slot 7, and then perform on band B at time slot 8. According to Table 23, the user equipment 102 may switch 1Tx on band A to band C to support 1-port transmission on band C at time slot 7 (corresponding to switching from transmission instance 1-4 to transmission instance 1-3). Then, the user equipment 102 may switch 1Tx on band D to band B to support 1-port transmission on band B at time slot 8 (corresponding to switching from transmission instance 1-3 to transmission instance 1-2).

[0160] However, for Tables 24-26, more than one transmit instance of a port transmission may be used on a specific band or on all bands. In these instances, ambiguity issues may arise. Figure 7 To illustrate, the user equipment 102 may perform a 1-port transmission on band D at time slot 6, then perform on band C at time slot 7, and then perform on band B at time slot 8. With particular reference to Table 24, an ambiguity problem may arise when the user equipment 102 is to perform a 1-port transmission on band C at time slot 7, and the previous transmission was performed on band D at time slot 6 using transmission instance 1-4. If the user equipment 102 is in switched UL, with or without a conventional CA mode, then from only the transmission instances in Table 24 the user equipment 102 may not know whether it should switch from transmission instance 1-4 to transmission instance 1-3 or transmission instance 1-2, because both transmission instances allow the user equipment 102 to transmit on band C. There are two possible ways to perform the switch.

[0161] In a first approach, the user equipment 102 may switch from transmission instance 1-4 to transmission instance 1-3. However, transmission instance 1-3 is not allowed to be transmitted on frequency band B. Therefore, if the user equipment 102 also transmits on frequency band B (e.g., on time slot 8), the user equipment 102 may perform two switching instances, switching from transmission instance 1-4 to transmission instance 1-3, and then switching from transmission instance 1-3 to transmission instance 1-2. In more detail, in transmission instance 1-4, the user equipment 102 has a first transmitter that is a transmitter used on frequency band D and a second transmitter that is a transmitter not used on frequency band A. Then, when the user equipment 102 first switches from transmission instance 1-4 to transmission instance 1-3, the user equipment 102 may switch the first transmitter on frequency band A to frequency band C while keeping the second transmitter on frequency band D. In transmission instance 1-3, the first transmitter that transmits on frequency band C is the transmitter that is used, and the second transmitter that does not transmit on frequency band D is the transmitter that is not used. Then, the user equipment 102 may perform a second UL Tx switching from the transmission instance 1-3 to the transmission instance 1-2, which switches the second unused 1Tx from the frequency band D to the frequency band B. At the end of the second switching, in the transmission instance 1-2, the user equipment 102 may have a transmitter configuration of 1Tx+1Tx located on the frequency band B and the frequency band C. In the transmission instance 1-2, the user equipment 102 may then transmit on the frequency band B using the second transmitter. In this first manner, the user equipment 102 performs two UL Tx switching instances involving two switching cycles, including a first switching cycle of the frequency band pair A+C (i.e., a switching cycle in which the user equipment 102 switches the 1Tx from the frequency band A to the frequency band C) and a second switching cycle of the frequency band pair D+B (i.e., a switching cycle in which the user equipment 102 switches the 1Tx from the frequency band D to the frequency band B).

[0162] The second way to perform switching is that the user equipment 102 performs a single switching instance from transmission instance 1-4 to transmission instance 1-2 (without switching to transmission instance 1-3 first). That is, the user equipment 102 can switch 1Tx from 1Tx on band A and band D to 1Tx on band B and 1Tx on band C during one switching cycle. In this way, the user equipment performs one UL Tx switching instance. The switching period of one switching instance can be the maximum value of the switching period of band pair A+C and the switching period of band pair B+D. When the network indicates two bands (or band pairs) of a certain number of configured bands (for example, three or four bands) via DCI or MAC-CE, and the user equipment 102 performs dynamic Tx switching between the indicated bands, the single instance switching and the corresponding switching period can also be used. The user equipment 102 may switch from a 1T+1T transmitter configuration on band A and band D to a 1T+1T transmitter configuration on band B and band C in one switching instance using a single switching cycle, i.e., switching from band pair A+D to band pair B+C.

[0163] As another example, referring to Table 25, the user equipment 102 may be in transmission instance 1-4, where it has one antenna port on band D. Therefore, in transmission instance 1-4, the user equipment 102 has a first transmitter on band D as a used transmitter, and a second transmitter on band A as an unused transmitter. In order to make the transmitter on band C, the user equipment 102 may switch to transmission instance 1-5 or transmission instance 1-2. In order to switch from transmission instance 1-4 to transmission instance 1-5, the first used Tx is switched from band D to band C, while the second unused Tx remains on band A. In order to switch from transmission instance 1-4 to transmission instance 1-2, the first used Tx is switched from band D to band C, while the second unused Tx on band A is switched to the fourth band, i.e., band B. In this scenario, the fourth frequency band (ie, band B) is not a frequency band used for UL transmission after switching, it is not a frequency band used for previous UL transmission before switching, and it is not a frequency band with Tx not used before switching.

[0164] For such embodiments involving UL Tx switching with four frequency bands, such as illustrated with respect to FIGS. 22-26 , the user equipment 102 may perform UL Tx switching according to a pre-configuration, predetermined rules, default behavior, or additional signaling indicating how to switch unused transmitters, such as previously described.

[0165] Embodiment 1-4:

[0166] In another embodiment in which the user equipment 102 performs UL transmissions on four frequency bands including bands A, B, C, and D, the transmitter configuration for the four frequency bands indicating the number of Tx for each frequency band may be: 1T-1T-1T-2T, one carrier on each frequency band. According to this transmitter configuration, only one frequency band (e.g., band D) may support more than one transmitter chain. In some embodiments, the transmission switching option parameter, i.e., uplinkTxSwitchingOption, is set to "switchUL" so that the user equipment 102 transmits without supporting simultaneous transmissions on two frequency bands. Thus, when operating in switchUL mode, the user equipment 102 performs UL uplink transmissions on one of the frequency bands A, B, C, or D. Under these conditions, possible combinations of the number of antenna ports for the uplink transmission examples in Table 22 above are listed in Tables 27-30 below.

[0167]

[0168] Table 27: Example mapping of four frequency bands with 1T-1T-1T-2T in Switched UL mode

[0169]

[0170] Table 28: Example mapping of four frequency bands with 1T-1T-1T-2T in Switched UL mode

[0171]

[0172] Table 29: Example mapping of four frequency bands with 1T-1T-1T-2T in switched UL mode Table 6-4 includes another mapping of frequency bands A+B+C+D with 1T-1T-1T-2T in “switched UL” mode for a conventional CA example

[0173]

[0174] Table 30: Example mapping of four bands with 1T-1T-1T-2T in Switched UL mode including conventional CA

[0175] In some UL Tx switching using the transmission examples in Tables 27-30, bands A and C are FDD bands, and bands B and D are TDD bands. Figure 7 The slot frame structure of describes further examples of UL Tx switching using the transmission examples in Tables 27-30.

[0176] Referring specifically to Table 27, for 1-port transmission, the transmission instances are all unique to each other, and therefore do not create any ambiguity issues for UL Tx switching. However, switching between the transmission instances in Table 27 may use an additional or undesirably large number of switching cycles. In order to use Figure 7 To illustrate, the user device 102 may perform 1-port transmission on Band D at time slot 6, then on Band C at time slot 7, and then on Band B at time slot 8. According to Table 27, the user device 102 may switch 1Tx from Band D to Band C to support 1-port transmission on Band C at time slot 7 (e.g., switching from transmission instance 2-4 to transmission instance 1-3). Then, the user device 102 may switch 1Tx from Band C to Band B to support 1-port transmission on Band B at time slot 8 (e.g., switching from transmission instance 1-3 to transmission instance 1-6).

[0177] However, for Table 28-30, more than one transmit instance of a "one-port" transmission may be used on a specific band or on all bands. In these instances, ambiguity issues may arise. Figure 7 2-4, the user equipment 102 may perform a 1-port transmission on band D on time slot 6, then perform on band C on time slot 7, and then perform on band B on time slot 8. According to Table 28, when the user equipment 102 is to perform a 1-port transmission on band C on time slot 7, and the user equipment 102 performed the previous transmission on band D on time slot 6 using transmission instance 2-4, an ambiguity problem may occur. In this case, if in switchedUL mode, based only on Table 28, the user equipment 102 may not know whether to switch from transmission instance 2-4 to transmission instance 1-3 or transmission instance 1-2, because both transmission instances support transmission on band C. There are two possible ways to perform the switch.

[0178] In a first approach, the user device 102 may first switch from transmission instance 2-4 to transmission instance 1-3. When transmitting on frequency band D using transmission instance 2-4, the first device 102 may have a first transmitter as a transmitter used on frequency band D and a second transmitter as a transmitter also not used on frequency band D. To switch from transmission instance 2-4 to transmission instance 1-3, the user device 102 may switch the first transmitter on frequency band D to frequency band C while keeping the second transmitter not used still on frequency band D. In transmission instance 1-3, the first transmitter is still the transmitter used, while the second transmitter is still the transmitter not used. Then, in order to be able to transmit on frequency band B (e.g., on time slot 8), the user device 102 may perform a second switch from transmission instance 1-3 to transmission instance 1-2, wherein the user device 102 switches the second transmitter not used on frequency band D to frequency band B while keeping the first transmitter on frequency band C. At the end of the second switching instance, the user equipment 102 may have a transmitter configuration of 1Tx+1Tx on band B and band C. In this first approach, the user equipment 102 performs two UL Tx switching instances using two switching cycles, including a first switching cycle for band pair D+C (e.g., a first switching cycle for switching 1Tx from band D to band C) and a second switching cycle for band pair D+B (e.g., a second switching cycle for switching 1Tx from band D to band B).

[0179] In the second way, in transmission instance 2-4, the user equipment 102 can switch using only one switching instance with only one switching period, and still be able to transmit on band C on time slot 7 and on band B on time slot 8. In particular, the user equipment 102 can perform a single switching instance of switching from transmission instance 2-4 to transmission instance 1-2. During the single switching instance, the user equipment 102 has 2Tx on band D, and switches 1Tx from band D to band B, and switches 1Tx from band C to band B. In this way, the user equipment 102 performs one UL Tx switching instance. For this single UL Tx switching instance, the switching period can be the maximum of the switching period of the band pair D+C (e.g., the switching period of switching between bands D and C) and the switching period of the band pair D+B (e.g., the switching period of switching between bands D and B). When the network indicates two bands (or band pairs) of a certain number of configured bands (e.g., three or four bands) via DCI or MAC-CE, and the user equipment 102 performs dynamic Tx switching between the indicated bands, the single instance switching and the corresponding switching cycle may also be used. During a single switching cycle, the user equipment 102 may switch from Tx on band D to a transmitter configuration of 1T+1T on band B and band C in one switching instance.

[0180] For such embodiments involving UL Tx switching with four frequency bands, such as illustrated with respect to FIGS. 27-30 , the user equipment 102 may perform UL Tx switching according to a pre-configuration, predetermined rules, default behavior, or additional signaling indicating how to switch unused transmitters, such as previously described.

[0181] Embodiment 1-5:

[0182] In another embodiment in which the user equipment 102 performs UL transmission on four frequency bands including bands A, B, C, and D, the transmitter configuration for the four frequency bands indicating the number of Tx for each frequency band may be: 1T-1T-2T-2T, with one carrier on each frequency band. According to the transmitter configuration, only one transmission chain may be configured for band A and band B, while at most 2 transmission chains may be configured for band C and band D. In some of these embodiments, the transmission switching option parameter, i.e., uplinkTxSwitchingOption, is set to "switchUL" so that the user equipment 102 transmits without supporting simultaneous transmission on two frequency bands. Therefore, when operating in switchUL mode, the user equipment 102 performs UL transmission on one of bands A, B, C, or D. Under these conditions, the transmission chains for the above are listed in Tables 31-34 below.

[0183] Table 22 shows possible combinations of the number of antenna ports for uplink transmission examples.

[0184]

[0185] Table 31: Example mapping of four frequency bands with 1T-1T-2T-2T in Switched UL mode

[0186]

[0187] Table 32: Example mapping of four frequency bands with 1T-1T-2T-2T in Switched UL mode

[0188]

[0189]

[0190] Table 33: Example mapping of four frequency bands with 1T-1T-2T-2T in Switched UL mode

[0191]

[0192] Table 34: Example mapping of four bands with 1T-1T-2T-2T in Switched UL mode including conventional CA

[0193] In some UL Tx switching using the transmission examples in Tables 31-34, bands A and B are FDD bands, and bands C and D are TDD bands. Figure 7 The slot frame structure of describes further examples of UL Tx switching using the transmission examples in Tables 31-34.

[0194] With particular reference to Table 31, for 1-port transmission, the transmission instances are all unique to each other, and therefore do not create any ambiguity issues for UL Tx switching. However, switching between the transmission instances in Table 31 may use an additional or undesirably large number of switching cycles. In order to use Figure 7 To illustrate, the user device 102 may perform a 1-port transmission on band D at time slot 6, then perform it on band C at time slot 7, and then perform it on band B at time slot 8. According to Table 31, the user device 102 may switch 2Tx on band D to band C to support 1-port transmission on band C (e.g., switching from transmission instance 2-4 to transmission instance 2-3). Then, the user device 102 may switch 1Tx on band C to band B to support 1-port transmission on band B (e.g., switching from transmission instance 2-3 to transmission instance B), where instance B should be instance 1-2 (i.e., 0T+1T+1T+0T) here. In another example, if the user device 102 is to send a 1-port transmission on band B, and the user device 102 performed the previous transmission using transmission instance 2-4, the user device 102 may switch 1Tx on band D to band C. That is, the user device 102 can switch from sending instance 2-4 to sending instance B, where instance B here is instance 1-6 (ie, 0T+1T+0T+1T).

[0195] However, for Tables 31-34, more than one transmit instance of a 1-port transmission may be used for a specific band or for all bands. In these instances, ambiguity issues may arise. Figure 73, the user equipment 102 may perform a 1-port transmission on frequency band D on time slot 6, then perform on frequency band C on time slot 7, and then perform on frequency band B on time slot 8. According to Table 32, when the user equipment 102 is to perform a 1-port transmission on frequency band C on time slot 7, and the user equipment 102 performed the previous transmission on frequency band D on time slot 6 using transmission instance 2-4, an ambiguity problem may occur. In this case, if in switched UL, the user equipment may not know whether to switch from transmission instance 2-4 to transmission instance 2-3 or transmission instance 1-2, because both transmission instances allow the user equipment 102 to transmit on frequency band C. There are two possible ways to perform the switch.

[0196] In the first manner, the user equipment 102 may first switch from the transmission instance 2-4 to the transmission instance 2-3, that is, the 2Tx on the frequency band D may be switched to the 2Tx on the frequency band C. Then, the user equipment 102 may perform a second switching from the transmission instance 2-3 to the transmission instance 1-2, wherein the user equipment 102 switches the 1Tx on the frequency band C to the frequency band B while keeping the other 1Tx on the frequency band C. At the end of the second switching instance, the user equipment 102 may have a transmitter configuration of 1Tx+1Tx on the frequency band B and the frequency band C. In the first manner, the user equipment 102 performs two UL Tx switching instances using two switching cycles, which include a first switching cycle for the frequency band pair D+C (e.g., a first switching cycle for switching 2Tx from the frequency band D to the frequency band C) and a second switching cycle for the frequency band pair C+B (e.g., a second switching cycle for switching 1Tx from the frequency band C to the frequency band B).

[0197] In the second manner, the user equipment 102 may perform switching using only one switching instance with only one switching period. In particular, the user equipment 102 may perform a single switching instance of switching from transmission instance 2-4 to transmission instance 1-2. During the single switching instance, the user equipment 102 has 2Tx on band D, and switches 1Tx on band D to band B, and switches the second 1Tx on band D to band C. In this way, the user equipment 102 performs one UL Tx switching instance, and in this way, it is still possible to transmit on band C when on time slot 7 and on band B when on time slot 8. For this single UL Tx switching instance, the switching period may be the maximum of the switching period of the band pair D+C (e.g., the switching period of switching from band D to band C) and the switching period of the band pair D+B (e.g., the switching period of switching from band D to band B).

[0198] In another example with reference to Table 34, the user equipment 102 may be in transmission instance 1-1 such that it has a first transmitter as a used Tx on one port (1P) on band A and a second transmitter as a non-used Tx on band B. In order to transmit on band C, the user equipment 102 may switch from transmission instance 1-1 to transmission instance 1-2 or transmission instance 2-3. If the user equipment 102 switches to transmission instance 1-2, the user equipment 102 may switch the first used Tx on 1P from band A to band C, while the second non-used Tx on band B remains on band B. In addition, if the user equipment 102 switches from transmission instance 1-1 to transmission instance 2-3, the user equipment 102 may switch both the first used Tx on band A and the second non-used Tx on band B to band C for UL transmission after switching.

[0199] For such embodiments involving UL Tx switching with four frequency bands, such as illustrated with respect to FIGS. 31-34 , the user equipment 102 may perform UL Tx switching according to a pre-configuration, predetermined rules, default behavior, or additional signaling indicating how to switch unused transmitters, such as previously described.

[0200] Furthermore, in the various embodiments described above, each frequency band has only one carrier.As described above, similar UL Tx switching may be performed across frequency bands, where at least one of the frequency bands includes at least two carriers (eg, at least two contiguous carriers).

[0201] Example 2

[0202] Figure 8 A flow chart of an example method 800 for wireless communication related to frequency band pairs and / or frequency band pair patterns is shown. At block 802, the network device 104 determines a frequency band pair pattern or frequency band pairs for one or more user equipment to perform uplink (UL) transmitter (Tx) switching. At block 804, the network device 104 sends MAC-CE, DCI, or RRC signaling for indicating or configuring the frequency band pair pattern or frequency band pairs.

[0203] Fig. 9 A flow chart of another example method 900 for wireless communication related to band pairs and / or band pair patterns is shown. At block 902, the user equipment 102 receives MAC-CE, DCI, or RRC signaling indicating or configuring a band pair pattern or band pair for uplink (UL) transmitter (Tx) switching. At block 904, the user equipment 102 transmits an UL transmission using the UL Tx switching according to the band pair pattern or band pair.

[0204] In more detail, in various embodiments of method 800 and / or method 900, the network device 104 indicates two frequency bands out of a specific configured number of frequency bands (e.g., three or four frequency bands), any two of the configured frequency bands may be a frequency band pair, and in instances where there are no additional restrictions on the frequency band pairs, there may be a total of six frequency band pairs within the four frequency bands of the band combination (BC). After the network device 104 selects and / or indicates the two frequency bands, the user equipment 102 may perform UL Tx switching according to the indicated two frequency bands. For example, if the two frequency bands currently available are band 1 and band 2, after the network device 104 indicates (e.g., via DCI or MAC CE) that the selected two frequency bands are band 3 and band 4, the user equipment 102 may perform UL Tx switching within band 3 and band 4. For example, returning to Figure 4 , the user equipment 102 can currently perform UL Tx in cell 1 and cell 2 from frequency band 1 and frequency band 2. Then, if cell 3 and cell 4 from frequency band 3 and frequency band 4 are selected from the four cells configured in the four frequency bands (for example, by network indication, and / or by cell or frequency band switching signaling), the user equipment 102 can perform UL Tx switching within frequency band 3 and frequency band 4 for subsequent UL transmission until the next indication of the network device 104.

[0205] Additionally or alternatively, for embodiments where one or more TDD bands exist within the configured three or four bands, band pair switching may be frequent, and band pair switching signaling may be sent frequently. Table 35 below shows four bands with different UL / DL configurations, carrier frequencies, and system bandwidths. It is assumed that there is one carrier on each band.

[0206]

[0207] Table 35: Band configuration for four bands

[0208] If only one band pair is indicated by MAC-CE or DCI, DCI-based band pair switching signaling may be frequently sent, while MAC-CE-based band pair switching signaling may not be feasible due to, for example, a MAC-CE processing time of about 3 milliseconds.

[0209] Fig.10 The frame structure of four frequency bands is shown, and each time slot is designed as downlink (D), uplink (U) or special (S), similar to the above Figure 6 and Figure 7 .like Fig.10As shown, it is assumed that there are five possible frequency band pairs: A+C, B+D, A+D, B+C, and C+D. Frequency band pair switching signaling can be sent up to 6 times in a radio frame. Correspondingly, the frequency band pair switching signaling may include: an indication of switching to frequency band pair A+C in time slot 1, an indication of switching to frequency band pair C+D in time slots 2 to 4, an indication of switching to frequency band pair A+C in time slots 5 to 6, an indication of switching to frequency band pair C+D in time slot 7, an indication of switching to frequency band pair B+D in time slots 8 to 9, and an indication of switching to frequency band pair C+D in time slot 0.

[0210] In order to avoid frequently indicating the switching of frequency band pairs through MAC-CE or DCI, the user equipment 102 and / or the network device 104 may adopt or apply one or more of the following solutions.

[0211] In the first scheme (Scheme 1): the network device 104 and / or the user equipment 102 may use MAC-CE or DCI to indicate a band pair pattern. The indicated band pair pattern may be from a plurality of band pair patterns. For at least some embodiments, all or at least some of the plurality of band pair patterns may be configured by RRC. In some embodiments, the band pair pattern is configured within a period, which period is, for example, a radio frame, one or more TDD frame structure periodicities (e.g., TDD DL / UL configuration periodicity), or a configured period. In addition, a period of multiple time slots including an SCS of a cell or carrier using one of the configured 3 or 4 bands may include one of the following: (1) the minimum SCS of a cell or carrier of one of the configured 3 or 4 bands; (2) the maximum SCS of a cell or carrier of one of the configured 3 or 4 bands; or (3) a configured or anchored or predefined cell or carrier of one of the configured 3 or 4 bands. In the instance where the SCS of two or more bands are the same, the network device 104 can configure the band pair pattern using RRC signaling of the cell group, or use one of the cells to configure the band pair pattern, such as the cell with the lowest cell index. For example, the SCS of the UL BWP of the carrier or cell on band A is 15kHz, and the other SCSs are 30KHz, 30KHz, 60Khz. The network device 104 can configure the band pair pattern using 15khz on band A. For example, the network device 104 can determine that the band pair A+B occupies one time slot of SCS=15Khz on band A and occupies two time slots of SCS=30khz on band B.

[0212] For further explanation, assume that the period of the band pair pattern is ten time slots, e.g. Fig.10The ten time slots shown. In addition, it is assumed that the first band pair pattern is: {C+D, A+C, C+D, C+D, C+D, A+C, A+C, C+D, B+C, B+C} on each time slot, and the second band pair pattern is: {C+D, A+D, C+D, C+D, C+D, A+D, A+D, C+D, B+D, B+D} on each time slot. In some embodiments, these two band pair patterns can be configured by RRC. The band pair pattern can be used based on the indication of MAC-CE or DCI. In addition, for at least some embodiments, the user equipment 102 can use the band pair pattern indicated by DCI or MAC-CE until the next band pair pattern is indicated by MAC-CE or DCI. In addition, in some embodiments, the band pair pattern may include band pairs for time slots less than all time slots in one cycle. In particular, in these embodiments, the U time slot / symbol is only located on at most two bands. For example, using the exemplary ten-slot cycle described above, in some embodiments, the band pair pattern may include band pairs for less than all ten slots. For example, a first band pair may be: {A+C, A+C, A+C, B+C, B+C} on slots 1 / 5 / 6 / 8 / 9, and a second band pair pattern may be: {A+D, A+D, A+D, B+D, B+D} on slots 1 / 5 / 6 / 8 / 9.

[0213] In a second solution (Solution 2), the user equipment 102 and / or the network device 104 may use MAC-CE to indicate at most N frequency band pairs, where each of the N frequency band pairs has a duration within a cycle. In any of the various embodiments, N may be a fixed or preconfigured value, or may be configured by RRC. For example, refer to Fig.10 , N=10, corresponding to ten time slots of the cycle. Correspondingly, the MAC-CE may indicate: {(1) a frequency band pair C+D with a duration equal to 1 time slot, (2) a frequency band pair A+C with a duration equal to 1 time slot, (3) a frequency band pair C+D with a duration equal to 3 time slots, (4) a frequency band pair A+C with a duration equal to 2 time slots, (5) a frequency band pair C+D with a duration equal to 1 time slot, (6) a frequency band pair B+C with a duration equal to 1 time slot, (7) null, (8) null, (9) null, and (10) null}. The user equipment 102 may use the frequency band pair pattern indicated by the MAC-CE. In addition, in some embodiments, the user equipment 102 may use the frequency band pair pattern until the MAC-CE indicates the next frequency band pair pattern.

[0214] In a third solution (Solution 3), the user equipment 102 and / or the network device 104 may use MAC-CE to indicate a frequency band pair pattern within a period. For illustration, for example, again referring to Fig.10, assuming that the period of the band pair pattern is ten time slots. The MAC-CE may indicate that the band pair pattern is: {C+D, A+C, C+D, C+D, C+D, A+C, A+C, C+D, B+D, B+D}, with one band pair per time slot. The user equipment 102 may then use the band pair pattern indicated by the MAC-CE. In addition, in some embodiments, the user equipment 102 may use the band pair pattern until the MAC-CE indicates the next band pair pattern.

[0215] In the fourth solution (Scheme 4), the band pair pattern can be configured through RRC signaling. Using this solution can avoid or prevent the use of dynamic signaling to indicate band pair switching or band pair pattern. For example, using Fig.10 , assuming that the period of the band pair pattern is ten time slots, the band pair pattern is configured by RRC, and the band pair pattern is: {C+D, A+C, C+D, C+D, C+D, A+C, A+C, C+D, B+D, B+D}, with one band pair in each time slot.

[0216] By using any of the above four schemes for indicating frequency band pairs and / or frequency band pair patterns, UL Tx switching can be reduced. In addition, in various embodiments, indicating frequency band pairs or frequency band pair patterns, for example according to the above schemes, can avoid too frequent indication of frequency band pair switching through MAC-CE or DCI, especially for embodiments in which one or more TDD frequency bands exist within a configured number (e.g., three or four) of frequency bands. In addition, in any of the various embodiments, the network device 104 can indicate the same frequency band pair pattern or different frequency band pair patterns for different user equipments 104 according to the network implementation.

[0217] Example 2-1:

[0218] Additionally or alternatively, for at least some embodiments, the user device 102 and / or the network device 104 may use a band pair pattern, wherein the user device 102 may perform dynamic UL Tx switching across all supported transmission instances based on UL scheduling (e.g., via UL grant and / or RRC configuration for UL transmission).

[0219] In addition, as described above, for embodiments or situations where there are one or more TDD bands within a configured number (e.g., three or four) of bands, band pair switching may be frequent. For example, as shown in Table 35, four bands (one carrier on each band) may have different UL / DL configurations, carrier frequencies, and system bandwidths. In addition, as shown in Table 35, Fig.10As shown in the example in , using four frequency bands can provide five possible frequency band pairs: A+C, B+D, A+D, B+C and C+D, and the RRC configuration can provide a frequency band pair pattern including one frequency band pair in each time slot, for example: {C+D, A+C, C+D, C+D, C+D, A+C, A+C, C+D, B+D, B+D}, for a time period of ten time slots. In other embodiments, frequency band pairs or frequency band pair patterns can be derived by other methods.

[0220] In some embodiments, the user equipment 102 may support less than all possible switching instances (i.e., less than all possible switching from one transmission instance to another transmission instance). In contrast, when switching to a particular frequency band pair, the user equipment 102 may only support a limited number of switching instances. This in turn may reduce the complexity of the UL Tx switching implementation. For illustration, for example, assume that the user equipment 102 is configured to switch between the transmission instances listed in Table 12, and the user equipment 102 is configured to communicate on ten time slots, for example, in Fig.10 In order to switch to the frequency band pair A+C in time slot 1, the user equipment 102 may only support switching from transmission instances 10, 9, and 8 to transmission instances 3, 4, and 9 respectively; in order to switch to the frequency band pair C+D in time slots 2 to 4, the user equipment 102 may only support switching from transmission instances 3, 4, and 9 to transmission instances 10, 9, and 8 respectively; in order to switch to the frequency band pair A+C in time slots 5 to 6, the user equipment 102 may only support switching from transmission instances 10, 9, and 8 to transmission instances 3, 4, and 9 respectively; In order to switch to band pair C+D in time slot 7, user equipment 102 may only support switching from transmission instances 3, 4, 9 to transmission instances 10, 9, 8, respectively; in order to switch to band pair B+D in time slots 8 to 9, user equipment 102 may only support switching from transmission instances 10, 9, 8 to transmission instances 2, 7, 10, respectively; and in order to switch to band pair C+D in time slot 0, user equipment 102 may only support switching from transmission instances 2, 7, 10 to transmission instances 10, 9, 8, respectively. As a result, with this band pair pattern, user equipment 102 may not switch to or from transmission instances 1, 5, or 6, which may desirably reduce UE complexity. In addition, in various embodiments, different user equipment 102 may be instructed to use the same band pairs or band pair patterns as each other or different band pairs or band pair patterns as each other, which may depend on network implementation.

[0221] Furthermore, in some embodiments, the switching period between the two frequency band pairs may be determined by one of the following:

[0222] (1) The switching period of the previous band pair;

[0223] (2) Switching period of the target frequency band pair;

[0224] (3) the larger of the switching period of the previous frequency band pair and the switching period of the target frequency band pair;

[0225] (4) reported by the user equipment 102 between two frequency band pairs, where the value may be a single value or multiple separate values ​​for switching between different frequency band pairs;

[0226] (5a) in the case of having three frequency bands and switching from 2Tx on the first frequency band (Band C) to 1Tx+1Tx on the second and third frequency bands (Band A and Band B) (i.e., the band pair switching is switching from band pair A+C or B+C to band pair A+B), the maximum value of the switching period from the first frequency band to the second frequency band and the switching period from the first frequency band to the third frequency band; or

[0227] (5b) In the case of having four frequency bands and switching from 1Tx+1Tx on the first and second frequency bands (e.g., band C and band D) to 1Tx+1Tx on the third and fourth frequency bands (e.g., band A and band B) (i.e., the band pair switching is switching from band pair C+D to band pair A+B), the maximum value of the switching period of the band pairs of the four frequency bands, for example, the maximum value of the switching period of the following band pairs: A+C, A+D, B+C, and B+D.

[0228] In summary, the band pair pattern can be used to reduce the number of used transmission and / or switching instances from the total number of potential transmission and / or switching instances, which can desirably reduce UE complexity. In an embodiment, the reduction in complexity can be experienced, especially when one or more TDD bands exist within a configured number of (e.g., 3 or 4) bands.

[0229] Example 2-2:

[0230] Additionally or alternatively, the MAC-CE indicates a band pair, or a band pair pattern may be indicated, for example, via the MAC-CE in conjunction with a CA option (or simultaneous transmission mode). In more detail, in some embodiments, the user equipment 102 may report that it does not support simultaneous transmission across two frequency bands (i.e., it supports operation in switchedUL mode (CA option 1), it supports simultaneous transmission across two frequency bands (i.e., it supports operation in dualUL mode (CA option 2)), or it may "both" support and not support simultaneous transmission across two frequency bands (i.e., it supports operation in switchedUL mode and dualUL mode). In various embodiments, the user equipment 102 may report its support for simultaneous transmission (switchedUL, dualUL, or both) for each band combination (BC). In some embodiments, the user equipment 102 may report a list of band pairs it supports (supportedBandPairListNR). In certain embodiments of these embodiments, the user equipment 102 may report the list based on the BC. In addition, for embodiments where the user equipment 102 reports "both", the simultaneous transmission mode (e.g., switchedUL or dualUL) may be indicated in conjunction with the band pairs or band pair patterns, such as the band pairs and / or band pair patterns indicated above.

[0231] To further illustrate, using the above scheme 4, for example, a band pair pattern combined with a CA option for each band pair can be configured through RRC signaling. This can avoid or prevent the use of dynamic signaling to indicate band pair switching or band pair patterns. For example, refer to Fig.10 , assuming that the period of the band pair pattern is ten time slots, and the band pair pattern with CA option (or simultaneous transmission mode) for each band pair is configured by RRC. An example band pair pattern incorporating CA option for each band pair may be: {C+D, A+C, C+D, C+D, C+D, A+C, A+C, C+D, B+D, B+D}, one band pair per time slot, incorporating switchedUL for band pair C+D, dualUL for band pair A+C, and dualUL for band pair B+D.

[0232] For another example including a supplementary UL (SUL) band and a non-supplementary or normal uplink (NUL) band, assume that the three or four bands include: one SUL band, one corresponding NUL band, and one or two other NUL bands. For example, assume that band A is a SUL band with a corresponding NUL band B, and band C and band D are each NUL bands. Assume that the period of the band pair pattern is ten time slots, and the band pair pattern with a CA option (or simultaneous transmission mode) for each band pair is configured by RRC. For example, the band pair pattern is: {C+D, A+B, C+D, C+D, C+D, A+B, A+C, C+D, B+D, B+D}, with one band pair on each time slot, combining switchedUL of band pair A+B, switchedUL of band pair A+C, dualUL of band pair C+D, and dualUL of band pair B+D. In other embodiments, the CA option (or simultaneous transmission mode) may be implicitly determined for each band pair.As a non-limiting example, only switchedUL is used for a SUL band combined with any other band, and dualUL is used for one NUL band combined with any other NUL band.

[0233] Additionally or alternatively, in one embodiment, the user equipment 102 may report a "switched UL" (CA option 1) or a "dual UL" (CA option 2) for each band pair. For some of these embodiments, the user equipment 102 may also report a supported band pair list (e.g., supportedBandPairListNR) for the band combination (BC). The user equipment 102 and / or the network device 104 may then implicitly determine the CA option (or simultaneous transmission mode), which may be implicitly determined in conjunction with the band pair or band pair pattern, for example, according to the above-described embodiments.

[0234] In summary, the CA option (or simultaneous transmission mode) can be explicitly or implicitly determined in conjunction with the band pair or band pair pattern. This in turn can provide greater flexibility to perform UL Tx switching within each band pair when more than one band pair is available on three or four bands.

[0235] The above description and accompanying drawings provide specific exemplary embodiments and implementations. However, the described subject matter can be embodied in various different forms, and therefore, the subject matter covered or claimed is intended to be interpreted as not being limited to any exemplary embodiment set forth herein. It is intended to provide a reasonably broad scope for the subject matter claimed or covered. Among other items, for example, the subject matter can be embodied as a method, device, component, system, or non-transient computer-readable medium for storing computer code. Therefore, the embodiment can, for example, take the form of hardware, software, firmware, storage medium, or any combination thereof. For example, the method embodiment described above can be implemented by a component, device, or system including a memory and a processor by executing a computer code stored in the memory.

[0236] Throughout the specification and claims, in addition to the explicitly stated meanings, terms may have implied or implicit nuanced meanings in the context. Likewise, the phrase "in one embodiment / implementation" as used herein does not necessarily refer to the same embodiment, and the phrase "in another embodiment / implementation" as used herein does not necessarily refer to a different embodiment. For example, the claimed subject matter is intended to include combinations of all or part of the exemplary embodiments.

[0237] Typically, terms can be understood at least in part based on usage in context. For example, terms such as "and", "or" or "and / or" as used herein can include a variety of meanings that can depend at least in part on the context in which such terms are used. Typically, "or", if used for an association list (such as A, B or C), is intended to represent A, B and C (here for inclusive meanings) as well as A, B or C (here for exclusive meanings). In addition, the term "one or more" as used herein, at least in part depending on the context, can be used to describe any feature, structure or characteristic in a singular sense, or can be used to describe a combination of features, structures or characteristics in a plural sense. Similarly, terms such as "a", "an" or "the" can be understood to convey singular usage or to convey plural usage, which depends at least in part on the context. In addition, the term "based on" can be understood to not necessarily be intended to convey an exclusive set of factors, but can instead allow the presence of additional factors that do not have to be explicitly described, again, at least in part depending on the context.

[0238] References to features, advantages, or similar language anywhere in this specification do not mean that all features and advantages that can be implemented with the present technical solution are included or should be included in any single implementation thereof. Rather, language referring to features and advantages is understood to mean that specific features, advantages, or characteristics described in conjunction with the embodiments are included in at least one embodiment of the present technical solution. Therefore, discussions of features and advantages and similar language anywhere in this specification may, but do not necessarily, refer to the same embodiment.

[0239] In addition, the described features, advantages and characteristics of the technical solution can be combined in any suitable manner in one or more embodiments. In view of the description herein, a person of ordinary skill in the relevant art will recognize that the technical solution can be practiced without one or more specific features or advantages of a particular embodiment. In other examples, additional features and advantages that may not be present in all embodiments of the technical solution may be found in certain embodiments.

[0240] The subject matter of the present disclosure may also relate to or include, among other things:

[0241] A first aspect includes a method for wireless communication, the method comprising: determining, by a user equipment, to perform uplink (UL) Tx switching on a first transmitter (Tx) and a second Tx, wherein, after the UL Tx switching, the first Tx is a used Tx for UL transmission, and the second Tx is an unused Tx for the UL transmission, wherein the UL Tx switching is performed according to a preconfiguration or signaling indicating how to perform the UL Tx switching on the unused Tx; and sending, by the user equipment, the UL transmission after the UL Tx switching.

[0242] The second aspect includes the first aspect, and further includes, wherein at least one of the following: the UL Tx switching is performed across three frequency bands, the three frequency bands include a first frequency band, a second frequency band, and a third frequency band, each frequency band has one or more carriers, the second frequency band and the third frequency band each support at most one Tx, and the first frequency band supports at most two Txs, wherein the previous UL transmission before the UL Tx switching is on the first frequency band, wherein the UL transmission after the UL Tx switching is on the second frequency band, and neither the previous UL transmission before the UL Tx switching nor the UL transmission after the UL Tx switching is on the third frequency band; the UL Tx switching is performed across three frequency bands, each frequency band has one or more carriers, the three frequency bands each support at most one Tx, wherein the previous UL transmission before the UL Tx switching is on the first frequency band among the three frequency bands, and the unused Tx is on the second frequency band among the three frequency bands before the UL Tx switching, wherein The frequency band used for the UL transmission after Tx switching is not the first frequency band and the second frequency band; the UL Tx switching is performed across four frequency bands, each frequency band has one or more carriers, and the four frequency bands each support at most one Tx, wherein the previous UL transmission before the UL Tx switching is on the first frequency band among the four frequency bands, and the unused Tx is on the second frequency band among the four frequency bands before the UL Tx switching, wherein the frequency band used for the UL transmission after the UL Tx switching is not the first frequency band and the second frequency band; the UL Tx switching is performed across four frequency bands, three frequency bands among the four frequency bands each support a maximum of one Tx, and one frequency band among the four frequency bands supports a maximum of two Txs, wherein the previous UL transmission before the UL Tx switching is on the one frequency band among the four frequency bands supporting a maximum of two Txs, and the first Tx and the second Tx are both on the one frequency band among the four frequency bands supporting a maximum of two Txs before the UL Tx switching; or the UL Tx switching is performed across four frequency bands, the first two frequency bands of the four frequency bands each supporting a maximum of one Tx, and the last two frequency bands of the four frequency bands each supporting a maximum of two Txs, wherein a previous UL transmission before the UL Tx switching is on one of the last two frequency bands supporting at most two Txs, and the first Tx and the second Tx are both on one of the last two frequency bands before the UL Tx switching.

[0243] A third aspect includes any one of the first or second aspects, and further includes, wherein the preconfiguration or the signaling indicates that when or after the UL Tx switching is performed, the unused Tx is to remain on a previous frequency band with one or more carriers.

[0244] The fourth aspect includes any one of the first or second aspects, and further includes, wherein the preconfiguration or the signaling indicates that when or after the UL Tx switching is performed, the unused Tx will switch to a frequency band having one or more carriers different from the previous frequency band.

[0245] The fifth aspect includes the fourth aspect and further includes, wherein one or more downlink (DL) time slots or symbols on the previous frequency band follow a previous time slot, on which a previous UL transmission was performed on the previous frequency band having one or more carriers.

[0246] The sixth aspect includes the fourth aspect, and further includes, wherein the different frequency band includes one of the following: a third frequency band, which is different from the second frequency band on which the UL transmission is performed after the UL Tx switching, and different from the first frequency band on which the previous UL transmission is performed before the UL Tx switching; the second frequency band on which the UL transmission is performed after the UL Tx switching; or a fourth frequency band, which is different from the second frequency band on which the UL transmission is performed after the UL Tx switching, different from the first frequency band on which the previous UL transmission is performed before the UL Tx switching, and different from the third frequency band where the unused Tx is located before the UL Tx switching.

[0247] The seventh aspect includes any one of the second to sixth aspects, and further includes, wherein one or two of the three or four frequency bands are supplemental uplink (SUL) bands, and the remaining frequency bands are normal uplink (NUL) bands, or the three or four frequency bands are all non-SUL or NUL bands.

[0248] The eighth aspect includes any one of the first to seventh aspects, and further includes, wherein, for the UL Tx switching, simultaneous transmission across two frequency bands is not supported.

[0249] A ninth aspect includes a method for wireless communication, the method comprising: determining, by the network device, a frequency band pair pattern or a frequency band pair for one or more user devices to perform uplink (UL) transmitter (Tx) switching; and sending, by the network device, a medium access control control element (MAC-CE), downlink control information (DCI), or radio resource control (RRC) signaling for indicating or configuring the frequency band pair pattern or the frequency band pair.

[0250] The tenth aspect includes a method for wireless communication, the method comprising: receiving, by a user equipment, a medium access control control element (MAC-CE), downlink control information (DCI), or radio resource control (RRC) signaling indicating or configuring a band pair pattern or band pair for uplink (UL) transmitter (Tx) switching; and sending, by the user equipment, a UL Tx switching according to the band pair pattern or band pair.

[0251] The eleventh aspect includes any one of the ninth or tenth aspect, and further includes, wherein determining the frequency band pair pattern includes determining the frequency band pair pattern from a plurality of frequency band pair patterns configured by RRC signaling using MAC-CE or DCI.

[0252] The twelfth aspect includes the eleventh aspect, and further includes, wherein the frequency band pair pattern corresponds to a time period including a plurality of time slots.

[0253] The thirteenth aspect includes any one of the ninth or tenth aspects, and further includes, wherein the frequency band pair pattern includes N frequency band pairs, wherein each frequency band pair corresponds to a corresponding time duration within a time period including a plurality of time slots.

[0254] The fourteenth aspect includes the thirteenth aspect, and further includes, wherein the band pair pattern including the N band pairs and the corresponding duration are indicated by the MAC-CE.

[0255] A fifteenth aspect includes any one of the ninth or tenth aspect, and further includes, wherein the MAC-CE indicates the frequency band pair pattern within a period including a plurality of time slots.

[0256] The sixteenth aspect includes any one of the ninth or tenth aspect, and further includes, wherein the frequency band pair pattern within a period including multiple time slots is configured by the RRC signaling.

[0257] The seventeenth aspect includes any one of the twelfth, thirteenth, fifteenth, or sixteenth aspects, and further includes, wherein the period including multiple time slots includes: at least one time division duplex (TDD) periodicity, fixed value, or configured value.

[0258] The eighteenth aspect includes any one of the twelfth, thirteenth, fifteenth, or sixteenth aspects, and further includes, wherein the period including multiple time slots uses the subcarrier spacing (SCS) of a cell or carrier of one of the three or more configured frequency bands, and includes: the minimum or maximum SCS of a cell or carrier of one of the three or more configured frequency bands, or a configured, anchored or predefined cell or carrier of one of the three or more configured frequency bands.

[0259] The nineteenth aspect includes the seventeenth aspect and further includes, wherein the frequency band pair pattern is configured or indicated by one of: each frequency band pair of each time slot of all time slots in the multiple time slots; or each frequency band pair of each time slot of less than all time slots in the multiple time slots.

[0260] The twentieth aspect includes the nineteenth aspect and further includes, wherein the time slots that are less than all of the multiple time slots include UL time slots or symbols located on at least three of the three or more configured frequency bands.

[0261] The twenty-first aspect includes any one of the ninth to twentieth aspects, and further includes, wherein the user equipment uses the frequency band pair pattern to perform the UL Tx switching until a next MAC-CE or a next DCI indicates a next frequency band pair pattern.

[0262] The twenty-second aspect includes any one of the first to twenty-second aspects, and further includes, wherein the switching period of the UL Tx switching from two transmitters on the first frequency band to one transmitter on the second frequency band and one transmitter on the third frequency band or the switching period between two frequency band pairs is based on: a first switching period for switching between the first frequency band and the second frequency band or between the first frequency band and the third frequency band; a second switching period for switching between the second frequency band and the third frequency band; the larger of the first switching period and the second switching period; a single time period or multiple time periods reported by the user equipment; or the maximum switching period of the switching period of switching between the first frequency band and the second frequency band and the switching period of switching between the first frequency band and the third frequency band; in the case where the frequency band pair of the first frequency band and the second frequency band is switched to the frequency band pair of the third frequency band and the fourth frequency band, the maximum value of the switching periods of the four frequency band pairs of the first frequency band and the third frequency band, the first frequency band and the fourth frequency band, the second frequency band and the third frequency band, and the second frequency band and the fourth frequency band.

[0263] A twenty-third aspect includes a wireless communication device, which includes a processor and a memory, wherein the processor is configured to read code from the memory to implement any one of the first to twenty-second aspects.

[0264] A twenty-fourth aspect includes a computer program product comprising a computer-readable program medium, the computer-readable program medium including code stored thereon, which, when executed by a processor, causes the processor to implement any one of the first to twenty-second aspects.

[0265] In addition to the features mentioned in each independent aspect listed above, some examples may show, alone or in combination, optional features mentioned in the dependent aspects and / or as disclosed in the above description and shown in the drawings.

Claims

1. A method for wireless communication, the method comprising: Determining, by a user equipment, to perform uplink UL Tx switching on a first transmitter Tx and a second Tx, wherein after the UL Tx switching, the first Tx is a used Tx for UL transmission, and the second Tx is an unused Tx for the UL transmission, wherein the UL Tx switching is performed according to a preconfiguration or signaling indicating how to perform the UL Tx switching on the unused Tx; and The UL transmission is sent by the user equipment after the UL Tx switching.

2. The method according to claim 1, wherein: At least one of the following: The UL Tx switching is performed across three frequency bands, the three frequency bands include a first frequency band, a second frequency band, and a third frequency band, each frequency band has one or more carriers, the second frequency band and the third frequency band each support at most one Tx, and the first frequency band supports at most two Txs, wherein a previous UL transmission before the UL Tx switching is on the first frequency band, wherein a UL transmission after the UL Tx switching is on the second frequency band, and neither the previous UL transmission before the UL Tx switching nor the UL transmission after the UL Tx switching is on the third frequency band; The UL Tx switching is performed across three frequency bands, each of which has one or more carriers, each of the three frequency bands supporting at most one Tx, wherein a previous UL transmission before the UL Tx switching is on a first frequency band among the three frequency bands, and the unused Tx is on a second frequency band among the three frequency bands before the UL Tx switching, wherein a frequency band used for the UL transmission after the UL Tx switching is not the first frequency band and the second frequency band; The UL Tx switching is performed across four frequency bands, each frequency band having one or more carriers, the four frequency bands each supporting at most one Tx, wherein a previous UL transmission before the UL Tx switching is on a first frequency band among the four frequency bands, and the unused Tx is on a second frequency band among the four frequency bands before the UL Tx switching, wherein a frequency band used for the UL transmission after the UL Tx switching is not the first frequency band and the second frequency band; The UL Tx switching is performed across four frequency bands, three frequency bands among the four frequency bands each support a maximum of one Tx, and one frequency band among the four frequency bands supports a maximum of two Txs, wherein a previous UL transmission before the UL Tx switching is on the one frequency band among the four frequency bands supporting a maximum of two Txs, and both the first Tx and the second Tx are on the one frequency band among the four frequency bands supporting a maximum of two Txs before the UL Tx switching; or The UL Tx switching is performed across four frequency bands, first two of the four frequency bands each supporting a maximum of one Tx, and last two of the four frequency bands each supporting a maximum of two Txs, wherein a previous UL transmission before the UL Tx switching is on one of the last two frequency bands supporting at most two Txs, and both the first Tx and the second Tx are on one of the last two frequency bands before the UL Tx switching.

3. The method according to claim 1 or 2, wherein: The pre-configuration or the signaling indicates that when or after the UL Tx switching is performed, the unused Tx is to be maintained on a previous frequency band with one or more carriers.

4. The method according to claim 1 or 2, wherein: The preconfiguration or the signaling indicates that when or after the UL Tx switching is performed, the unused Tx will be switched to a frequency band having one or more carriers different from a previous frequency band.

5. The method according to claim 4, wherein: The one or more downlink DL time slots or symbols on the previous frequency band follow a previous time slot on which a previous UL transmission was performed on the previous frequency band having one or more carriers.

6. The method according to claim 4, wherein: The different frequency bands include one of the following: a third frequency band different from the second frequency band on which the UL transmission is performed after the UL Tx switching and different from the first frequency band on which the previous UL transmission is performed before the UL Tx switching; the second frequency band on which the UL transmission is performed after the UL Tx switching; or a fourth frequency band, the fourth frequency band being different from the second frequency band on which the UL transmission is performed after the UL Tx switching, being different from the first frequency band on which the previous UL transmission is performed before the UL Tx switching, and being different from the third frequency band on which the unused Tx is located before the UL Tx switching.

7. The method according to claim 2, wherein: One or two of the three or four frequency bands are supplementary uplink SUL frequency bands, and the remaining frequency bands are normal uplink NUL frequency bands, or the three or four frequency bands are all non-SUL or NUL frequency bands.

8. The method according to claim 1 or 2, wherein: For the UL Tx switching, simultaneous transmission across two frequency bands is not supported.

9. A method for wireless communication, the method comprising: The network device determines a frequency band pair pattern or a frequency band pair for one or more user equipments to perform uplink UL transmitter Tx switching; as well as The network device sends a medium access control element MAC-CE, downlink control information DCI, or radio resource control RRC signaling for indicating or configuring the frequency band pair pattern or the frequency band pair.

10. A method for wireless communication, comprising: The user equipment receives a medium access control control element MAC-CE, downlink control information DCI, or radio resource control RRC signaling indicating or configuring a frequency band pair pattern or frequency band pair for uplink UL transmitter Tx switching; and A UL transmission is sent by the user equipment using the UL Tx switching according to the band pair pattern or band pairs.

11. The method according to claim 9 or 10, wherein: Determining the frequency band pair pattern includes determining the frequency band pair pattern from a plurality of frequency band pair patterns configured by the RRC signaling using the MAC-CE or the DCI.

12. The method according to claim 11, wherein: The frequency band pair pattern corresponds to a time period including a plurality of time slots.

13. The method according to claim 9 or 10, wherein: The frequency band pair pattern includes N frequency band pairs, wherein each frequency band pair corresponds to a respective time duration within a time period including a plurality of time slots.

14. The method according to claim 13, wherein: The frequency band pair pattern including the N frequency band pairs and the corresponding time durations are indicated by the MAC-CE.

15. The method according to claim 9 or 10, wherein: The MAC-CE indicates the band pair pattern within a period including a plurality of time slots.

16. The method according to claim 9 or 10, wherein: The frequency band pair pattern within a period including a plurality of time slots is configured by the RRC signaling.

17. The method according to any one of claims 12, 13, 15 or 16, wherein: The period including a plurality of time slots includes at least one time division duplex (TDD) periodicity, a fixed value, or a configured value.

18. The method according to any one of claims 12, 13, 15 or 16, wherein: The period including multiple time slots uses the subcarrier spacing SCS of a cell or carrier of one of the three or more configured frequency bands, and includes: the minimum or maximum SCS of a cell or carrier of one of the three or more configured frequency bands, or a configured, anchored or predefined cell or carrier of one of the three or more configured frequency bands.

19. The method according to claim 17 or 18, wherein: The band pair pattern is configured or indicated by one of the following: each frequency band pair of each time slot of all the time slots in the plurality of time slots; or Less than each frequency band pair for each time slot of all time slots in the plurality of time slots.

20. The method according to claim 19, wherein: The time slots that are less than all time slots of the plurality of time slots include UL time slots or symbols located on at least three frequency bands of three or more configured frequency bands.

21. The method according to claim 9 or 10, wherein: The user equipment performs the UL Tx switching using the frequency band pair pattern until a next MAC-CE or a next DCI indicates a next frequency band pair pattern.

22. The method according to any one of claims 1 to 21, wherein: The UL Tx switching switching period from two transmitters on the first frequency band to one transmitter on the second frequency band and one transmitter on the third frequency band or the switching period between two frequency band pairs is based on: a first switching cycle of switching between the first frequency band and the second frequency band or between the first frequency band and the third frequency band; a second switching period of switching between the second frequency band and the third frequency band; the larger of the first switching period and the second switching period; a single time period or multiple time periods reported by the user equipment; or a maximum switching period of a switching period for switching between the first frequency band and the second frequency band and a switching period for switching between the first frequency band and the third frequency band; When the band pair of the first band and the second band is switched to the band pair of the third band and the fourth band, the maximum value among the switching cycles of the four band pairs of the first band and the third band, the first band and the fourth band, the second band and the third band, and the second band and the fourth band.

23. A wireless communication device, comprising a processor and a memory, wherein: The processor is configured to read code from the memory to implement the method according to any one of claims 1 to 22.

24. A computer program product, comprising a computer readable program medium, the computer readable program medium comprising code stored thereon, which, when executed by a processor, causes the processor to implement the method according to any one of claims 1 to 22.

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