Method and apparatus for transmitting or receiving signal in wireless communication system

Abstract

The method and apparatus for transmitting or receiving a signal in a wireless communication system disclosed in the present specification allow uplink switching to be performed among three or more frequency bands. Disclosed is a method in which, after an uplink handover, if only a 1-port transmission exists on a carrier of one frequency band, the frequency band in which one Tx chain not used for the 1-port transmission, among two Tx chains, is located, is clarified as a transmission after the uplink handover.

Description

Technical Field

[0001] The present disclosure relates to a method and an apparatus for use in a wireless communication system. Background Art

[0002] In general, wireless communication systems are being developed to cover a wide range in a diverse manner to provide communication services such as audio communication services, data communication services, etc. Wireless communication is a multiple access system that can support communication with multiple users by sharing available system resources (e.g., bandwidth, transmission power, etc.). For example, the multiple access system may include one of a code division multiple access (CDMA) system, a frequency division multiple access (FDMA) system, a time division multiple access (TDMA) system, an orthogonal frequency division multiple access (OFDMA) system, a single carrier frequency division multiple access (SC-FDMA) system, and the like. Summary of the invention

[0003] Technical issues

[0004] An object of the present disclosure is to provide a signal transmitting and receiving method and apparatus thereof for efficiently transmitting and receiving a signal in a wireless communication system.

[0005] Those skilled in the art should understand that the objectives that can be achieved using the present disclosure are not limited to the contents specifically described above, and the above and other objectives that can be achieved by the present disclosure will be more clearly understood from the following detailed description.

[0006] Technical Solution

[0007] The present disclosure provides a method and apparatus for transmitting and receiving signals in a wireless communication system.

[0008] In one aspect of the present disclosure, a method for transmitting and receiving signals by a user equipment (UE) in a wireless communication system is provided herein. The method comprises the following steps: configuring an uplink frequency band including a first frequency band, a second frequency band, and a third frequency band; based on the fact that the state of the transmission (Tx) chain after the uplink switching is not unique, receiving (i) a first parameter for indicating the state of the Tx chain and (ii) a second parameter for configuring an associated frequency band for the third frequency band; and in an operating state capable of supporting 1-port transmission (first transmission) on a carrier of each of the first frequency band and the second frequency band, performing 1-port transmission (second transmission) on a carrier on the third frequency band without transmission in the first frequency band and the second frequency band. The uplink switching is performed based on the second transmission. Based on the fact that the value of the first parameter indicates a Tx chain and the associated frequency band is configured by the second parameter, the UE considers performing 1-port transmission on a carrier of each of the third frequency band and the associated frequency band for the uplink switching.

[0009] In another aspect of the present disclosure, a method for sending and receiving signals by a base station (BS) in a wireless communication system is provided herein. The method includes the following steps: configuring an uplink frequency band for a UE including a first frequency band, a second frequency band, and a third frequency band; based on the fact that the state of the Tx chain after the uplink switching is not unique, sending to the UE (i) a first parameter for indicating the state of the Tx chain and (ii) a second parameter for configuring an associated frequency band for the third frequency band; and in an operating state capable of supporting 1-port transmission (first transmission) on a carrier of each of the first frequency band and the second frequency band, receiving a 1-port transmission (second transmission) on a carrier of the third frequency band from the UE without transmission in the first frequency band and the second frequency band. The uplink switching is performed based on the second transmission. Based on the fact that the value of the first parameter indicates a Tx chain and the associated frequency band is configured by the second parameter, the BS considers performing 1-port transmission on a carrier of each of the third frequency band and the associated frequency band for uplink switching.

[0010] In another aspect of the present disclosure, an apparatus, a processor, and a storage medium for performing a signal transmission and reception method are provided.

[0011] The apparatus may include an autonomous driving vehicle communicable with at least a UE, a network, and another autonomous driving vehicle other than the communication apparatus.

[0012] The above-mentioned aspects of the present disclosure are only some preferred embodiments of the present disclosure, and various embodiments reflecting the technical features of the present disclosure can be derived and understood by those skilled in the art from the following detailed description of the present disclosure.

[0013] Beneficial Effects

[0014] According to one embodiment of the present disclosure, when a control signal and a data signal are transmitted and received between communication devices, the signals can be transmitted and received more efficiently based on an operation different from that in the related art.

[0015] Those skilled in the art should understand that the effects that can be achieved through the present disclosure are not limited to the contents that have been specifically described above, and other advantages of the present disclosure will be more clearly understood from the following detailed description in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 The radio frame structure is shown.

[0017] Figure 2 The resource grid during the duration of a time slot is illustrated.

[0018] Figure 3 Figure 1 shows a self-contained time slot structure.

[0019] Figures 4 to 5 is a diagram illustrating a method of transmitting and receiving a signal according to an embodiment of the present disclosure.

[0020] Figures 6 to 9 An apparatus according to an embodiment of the present disclosure is illustrated. DETAILED DESCRIPTION

[0021] The following technologies may be used in various wireless access systems such as code division multiple access (CDMA), frequency division multiple access (FDMA), time division multiple access (TDMA), orthogonal frequency division multiple access (OFDMA), single carrier frequency division multiple access (SC-FDMA), etc. CDMA may be implemented as a radio technology such as Universal Terrestrial Radio Access (UTRA) or CDMA2000. TDMA may be implemented as a radio technology such as Global System for Mobile Communications (GSM) / General Packet Radio Service (GPRS) / Enhanced Data Rates for GSM Evolution (EDGE). OFDMA may be implemented as a radio technology such as Institute of Electrical and Electronics Engineers (IEEE) 802.11 (Wireless Fidelity (WiFi)), IEEE 802.16 (Worldwide Interoperability for Microwave Access (WiMAX)), IEEE 802.20, Evolved UTRA (E-UTRA), etc. UTRA is part of Universal Mobile Telecommunications System (UMTS). 3rd Generation Partnership Project (3GPP) Long Term Evolution (LTE) is a part of Evolved UMTS (E-UMTS) using E-UTRA, and LTE-advanced (LTE-A) is an evolution of 3GPP LTE. 3GPP New Radio or New Radio Access Technology (NR) is an evolved version of 3GPP LTE / LTE-A.

[0022] For clarity of description, the present disclosure will be described in the context of 3GPP communication systems (e.g., LTE and NR), which should not be construed as limiting the spirit of the present disclosure. LTE refers to technology beyond 3GPP TS 36.xxx version 8. Specifically, LTE technology beyond 3GPP TS 36.xxx version 10 is called LTE-A, and LTE technology beyond 3GPP TS 36.xxx version 13 is called LTE-A pro. 3GPP NR is a technology beyond 3GPP TS 38.xxx version 15. LTE / NR may be referred to as a 3GPP system. "xxx" specifies a technical specification number. LTE / NR may be collectively referred to as a 3GPP system. Background technology, terms, abbreviations, etc. as used herein refer to technical specifications published prior to the present disclosure. For example, the following documents may be referenced.

[0023] 3GPP NR

[0024] -38.211: Physical channels and modulation

[0025] -38.212: Multiplexing and channel compilation

[0026] -38.213: Physical layer procedures for control

[0027] -38.214: Physical layer procedures for data

[0028] -38.300: NR and NG-RAN general description

[0029] -38.331: Radio Resource Control (RRC) protocol specification

[0030] Figure 1 The radio frame structure for NR is shown.

[0031] In NR, UL and DL transmissions are configured on a frame basis. Each radio frame has a length of 10ms and is divided into two 5ms half-frames. Each half-frame is divided into five 1ms subframes. A subframe is divided into one or more time slots, and the number of time slots in a subframe depends on the subcarrier spacing (SCS). Depending on the cyclic prefix (CP), each time slot includes 12 or 14 OFDM (A) symbols. When a normal CP is used, each time slot includes 14 OFDM symbols. When an extended CP is used, each time slot includes 12 OFDM symbols. Symbols may include OFDM symbols (or CP-OFDM symbols) and SC-FDMA symbols (or discrete Fourier transform-extended-OFDM (DFT-s-OFDM) symbols).

[0032] Table 1 exemplarily shows that the number of symbols per slot, the number of slots per frame, and the number of slots per subframe vary according to the SCS in the normal CP case.

[0033] [Table 1]

[0034] SCS(15*2^u) <![CDATA[N slot symb ]]> <![CDATA[M frame，u slot ]]> <![CDATA[M subframe，u slot ]]> 15KHz(u=0) 14 10 1 30KHz(u=1) 14 20 2 60KHz(u=2) 14 40 4 120KHz(u=3) 14 80 8 240KHz(u=4) 14 160 16

[0035] *N slot symb : The number of symbols in a time slot

[0036] *N frame，u slot : Number of time slots in a frame

[0037] *N subframe，u slot : Number of time slots in a subframe

[0038] Table 2 shows that the number of symbols per slot, the number of slots per frame, and the number of slots per subframe vary according to SCS in the case of extended CP.

[0039] [Table 2]

[0040] SCS(15*2^u) <![CDATA[N slot symb ]]> <![CDATA[N frame，u slot ]]> <![CDATA[M subframe，u slot ]]> 60KHz(u=2) 12 40 4

[0041] In the NR system, different OFDM(A) parameter sets (e.g., SCS, CP length, etc.) may be configured for multiple cells aggregated for one UE. Therefore, the (absolute time) duration of a time resource (e.g., a subframe, a time slot, or a transmission time interval (TTI)) (referred to as a time unit (TU) for convenience) consisting of the same number of symbols may be configured differently between the aggregated cells.

[0042] In NR, various parameter sets (or SCS) can be supported to support various 5th generation (5G) services. For example, for an SCS of 15kHz, wide areas in the traditional cellular band can be supported, while for an SCS of 30kHz or 60kHz, dense urban areas, lower latency, and wide carrier bandwidth can be supported. For an SCS of 60kHz or higher, bandwidths greater than 24.25kHz can be supported to overcome phase noise.

[0043] The NR frequency band may be defined by two types of frequency ranges FR1 and FR2. FR1 and FR2 may be configured as described in Table 3 below. FR2 may be millimeter wave (mmW).

[0044] [Table 3]

[0045] Frequency range specification Corresponding frequency range Subcarrier spacing FR1 450MHz-7125MHz 15, 30, 60kHz FR2 24250MHz-52600MHz 60, 120, 240kHz

[0046] Figure 2 The resource grid during the duration of one time slot is shown.

[0047] A time slot includes multiple symbols in the time domain. For example, a time slot includes 14 symbols in the normal CP case and 12 symbols in the extended CP case. A carrier includes multiple subcarriers in the frequency domain. A resource block (RB) can be defined by multiple (e.g., 12) consecutive subcarriers in the frequency domain. Multiple RB interleavings (referred to as interleavings) can be defined in the frequency domain. Interleaving m∈{0, 1, ..., M-1} can be composed of (common) RBs{m, M+m, 2M+m, 3M+m, ...}. M represents the number of interleavings. A bandwidth part (BWP) can be defined by multiple consecutive (physical) RBs ((P)RBs) in the frequency domain and corresponds to a parameter set (e.g., SCS, CP length, etc.). A carrier can include up to N (e.g., five) BWPs. Data communication can be performed in an active BWP, and only one BWP can be enabled for a UE. Each element in a resource grid can be referred to as a resource element (RE), to which a complex symbol can be mapped.

[0048] In a wireless communication system, a UE receives information from a BS in a downlink (DL), and the UE transmits information to the BS in an uplink (UL). The information exchanged between the BS and the UE includes data and various control information, and there are various physical channels / signals according to the type / purpose of the information exchanged therebetween. A physical channel corresponds to a set of resource elements (REs) that carry information from a higher layer. A physical signal corresponds to a set of REs that are used by the physical layer but do not carry information from a higher layer. The higher layer includes a medium access control (MAC) layer, a radio link control (RLC) layer, a packet data convergence protocol (PDCP) layer, a radio resource control (RRC) layer, and the like.

[0049] DL physical channels include physical broadcast channel (PBCH), physical downlink shared channel (PDSCH) and physical downlink control channel (PDCCH). DL physical signals include DL reference signal (RS), primary synchronization signal (PSS) and secondary synchronization signal (SSS). DL RS includes demodulation reference signal (DM-RS), phase tracking reference signal (PT-RS) and channel state information reference signal (CSI-RS). UL physical channels include physical random access channel (PRACH), physical uplink shared channel (PUSCH) and physical uplink control channel (PUCCH). UL physical signals include UL RS. UL RS includes DM-RS, PT-RS and sounding reference signal (SRS).

[0050] Figure 3 The structure of a self-contained time slot is illustrated.

[0051] In the NR system, a frame has a self-contained structure in which a DL control channel, DL or UL data, a UL control channel, etc. can all be included in one time slot. For example, the first N symbols in a time slot (hereinafter, the DL control region) can be used to send a DL control channel, and the last M symbols in a time slot (hereinafter, the UL control region) can be used to send a UL control channel. N and M are integers greater than or equal to 0. The resource region (hereinafter, the data region) between the DL control region and the UL control region can be used for DL ​​data transmission or UL data transmission. For example, the following configuration can be considered. List the various parts in chronological order.

[0052] In the present disclosure, a base station (BS) may be, for example, a gNode B (gNB).

[0053] UL physical channel / signal

[0054] (1) PUSCH

[0055] The PUSCH may carry UL data (e.g., uplink shared channel (UL-SCH) transport blocks (TBs)) and / or uplink control information (UCI). The PUSCH may be sent based on a cyclic prefix orthogonal frequency division multiplexing (CP-OFDM) waveform or a discrete Fourier transform spread OFDM (DFT-s-OFDM) waveform. When the PUSCH is sent based on a DFT-s-OFDM waveform, the UE may send the PUSCH by applying transform precoding. For example, when transform precoding is not allowed (e.g., when transform precoding is disabled), the UE may send the PUSCH based on a CP-OFDM waveform. When transform precoding is allowed (e.g., when transform precoding is enabled), the UE may send the PUSCH based on a CP-OFDM waveform or a DFT-s-OFDM waveform. PUSCH transmissions may be dynamically scheduled by PDCCH (dynamic scheduling) or semi-statically scheduled by higher layer signaling (e.g., RRC signaling) (and / or layer 1 (L1) signaling (e.g., PDCCH)) (configured scheduling (CS)). Therefore, in dynamic scheduling, PUSCH transmissions may be associated with PDCCH, while in CS, PUSCH transmissions may not be associated with PDCCH. CS may include PUSCH transmissions based on type 1 configuration grants (CGs) and PUSCH transmissions based on type 2CGs. For type 1CG, all parameters for PUSCH transmissions may be signaled by higher layers. For type 2CG, some parameters for PUSCH transmissions may be signaled by higher layers, and the rest may be signaled via PDCCH. Basically, in CS, PUSCH transmissions may not be associated with PDCCH.

[0056] (2) PUCCH

[0057] PUCCH can carry UCI. UCI includes the following information.

[0058] -SR (Scheduling Request): SR is information for requesting UL-SCH resources.

[0059] -HARQ-ACK (Hybrid Automatic Repeat Request Acknowledgement): HARQ-ACK is a signal in response to the reception of a DL signal (e.g., PDSCH, SPS release PDCCH, etc.). The HARQ-ACK response may include positive ACK (ACK), negative ACK (NACK), DTX (discontinuous transmission), or NACK / DTX. HARQ-ACK may be used interchangeably with A / N, ACK / NACK, HARQ-ACK / NACK, etc. HARQ-ACK may be generated based on TB / CBG.

[0060] -CSI (Channel State Information): CSI is feedback information about a DL channel. CSI includes a channel quality indicator (CQI), a rank indicator (RI), a precoding matrix indicator (PMI), a precoding type indicator (PTI), and the like.

[0061] Table 4 shows the PUCCH format. The PUCCH format may be classified according to UCI payload size / transmission length (e.g., the number of symbols included in the PUCCH resource) and / or transmission structure. The PUCCH format may be classified into short PUCCH formats (PUCCH formats 0 and 2) and long PUCCH formats (PUCCH formats 1, 3, and 4) according to the transmission length.

[0062] [Table 4]

[0063]

[0064] (0)PUCCH format 0 (PF0)

[0065] - Supported UCI payload size: up to K bits (e.g., K=2)

[0066] -Number of OFDM symbols included in one PUCCH: 1 to X symbols (eg, X=2)

[0067] -Transmission structure: Only UCI signal is configured without DM-RS, and UCI status is transmitted by selecting and transmitting one of multiple sequences.

[0068] (1) PUCCH format 1 (PF1)

[0069] - Supported UCI payload size: up to K bits (e.g., K=2)

[0070] -Number of OFDM symbols included in one PUCCH: Y to Z symbols (e.g., Y=4 and Z=14)

[0071] -Transmission structure: UCI and DM-RS are configured in different OFDM symbols based on time division multiplexing (TDM). For UCI, a specific sequence is multiplied by the modulation symbol (e.g., QPSK symbol). Cyclic shift / orthogonal cover code (CS / OCC) is applied to both UCI and DM-RS to support code division multiplexing (CDM) between multiple PUCCH resources (compliant with PUCCH format 1) (in the same RB).

[0072] (2) PUCCH format 2 (PF2)

[0073] - Supportable UCI payload size: more than K bits (e.g., K=2)

[0074] -Number of OFDM symbols included in one PUCCH: 1 to X symbols (eg, X=2)

[0075] - Transmission structure: UCI and DMRS (DM-RS) are configured / mapped to the same symbol based on frequency division multiplexing (FDM), and coded UCI bits are transmitted by applying only inverse fast Fourier transform (IFFT) thereto without DFT.

[0076] (3) PUCCH format 3 (PF3)

[0077] - Supportable UCI payload size: more than K bits (e.g., K=2)

[0078] -Number of OFDM symbols included in one PUCCH: Y to Z symbols (e.g., Y=4 and Z=14)

[0079] -Transmission structure: UCI and DMRS are configured / mapped to different symbols based on TDM. The coded UCI bits are transmitted by applying DFT to them. To support multiplexing between multiple UEs, OCC is applied to UCI, and CS (or interleaved frequency division multiplexing (IFDM) mapping) is applied to DM-RS before DFT.

[0080] (4) PUCCH format 4 (PF4)

[0081] - Supportable UCI payload size: more than K bits (e.g., K=2)

[0082] -Number of OFDM symbols included in one PUCCH: Y to Z symbols (e.g., Y=4 and Z=14)

[0083] - Transmission structure: UCI and DMRS are configured / mapped to different symbols based on TDM. DFT is applied to the coded UCI bits without multiplexing between UEs.

[0084] Uplink switching of 3 or 4 uplink frequency bands

[0085] The above content can be applied in combination with the method proposed in the present disclosure (described later). Alternatively, the content can illustrate the technical features of the method proposed in the present disclosure.

[0086] In addition, the following methods can be equally applied to the above-mentioned NR system (licensed band) or shared spectrum. Therefore, it is obvious that in order to implement the technical concept of the present disclosure in the corresponding system, the terms, expressions and structures in this document can be modified to be suitable for the system.

[0087] Typically, due to the size of the UE, the number of antennas to be installed on the corresponding UE is limited. A UE with N transmission chains via N antennas can simultaneously support up to N 1-port UL transmissions or up to N-port UL transmissions. A method is needed to support UEs with limited transmission chains to effectively perform UL transmissions. In the following, an implementation of the present specification for UL transmission (Tx) switching is described. Most UEs developed to date support up to two Tx chains, so the implementation of the present specification is described below, assuming that the UE supports UL transmissions through up to two Tx chains (i.e., up to two ports). However, the implementation of the present specification is not limited to 1-port or 2-port UL transmissions, but can also be applied to N-port UL transmissions, where N can be greater than 2.

[0088] Figure 4 is a diagram illustrating the concept of UL transmission switching.

[0089] To improve the throughput and efficiency of UL transmission, NR Rel-16 provides UL Tx Switching (UTS), which switches the Tx chain connected to the UL carrier under specific conditions to enable the UE to effectively perform 1-port UL transmission or 2-port UL transmission by using up to two Tx chains. Figure 4 (a) illustrates 1Tx-2Tx switching between two carriers / bands, and Figure 4 (b) illustrates 2Tx-2Tx switching between two carriers / frequency bands.

[0090] For example, if UL transmission (hereinafter referred to as "previous transmission") is performed on carrier #1 having 1 Tx chain, and then UL transmission (hereinafter referred to as "current transmission") is configured / instructed to be performed on another carrier #2 having 2 Tx chains, the UE may switch the Tx chain connected to carrier #1 to carrier #2 to implement 2-port UL transmission on carrier #2. These UTS configuration and switching methods may be applied to band combinations corresponding to Evolved Universal Terrestrial Radio Access New Radio Dual Connectivity (EN-DC) without Supplementary UL (SUL), Independent SUL, and Inter-band CA. In NR Rel-17, additional conditions are introduced to extend the 1Tx-2Tx switching (i.e., switching between 1Tx chain and 2Tx chain) of the existing NR Rel-16 to 2Tx-2Tx switching (i.e., switching between 2Tx chain and 2Tx chain), and at the same time, the UTS between two carriers introduced in NR Rel-16 is extended to allow UTS between two different frequency bands (e.g., 1 carrier in one frequency band and 2 consecutive carriers in another frequency band).

[0091] When certain conditions are met and the UE is configured with uplinkTxSwitching via RRC signaling, the UE may ignore UL transmission during the uplink switching gap NTx1-Tx2. Tx1-Tx2 All UL transmissions are ignored during this period, including UL transmissions scheduled via DCI and UL transmissions configured by higher layer signaling (e.g., configured grant-based PUSCH). When uplinkTxSwitching-2T-Mode is configured via RRC signaling, the switching gap NTx1-Tx2 may be indicated by uplinkTxSwitchingPeriod2T2T provided from the UE to the BS via the UE capability report, otherwise the switching gap NTx1-Tx2 may be indicated by uplinkTxSwitchingPeriod provided from the UE to the BS via the UE capability report. Here, the RRC configuration uplinkTxSwitching may be provided to the UE as included in the configuration about the serving cell, and may include: uplinkTxSwitchingPeriodLocation, which indicates whether the location of the UL Tx switching period is configured on the UL carrier in the case of inter-band UL CA, SUL or (NG)EN-DC; and uplinkTxSwitchingCarrier, which indicates whether the configured carrier is carrier 1 or carrier 2 for dynamic UL Tx switching. The RRC parameter uplinkTxSwitching-2T-Mode indicates that 2Tx-2Tx switching mode is configured for inter-band UL CA or SUL, in which case the switching gap duration for the triggered UL switching can be equal to the switching time capability value reported for the switching mode. When the RRC parameter uplinkTxSwitching-2T-Mode is not provided and uplinkTxSwitching is configured, it can be interpreted as 1Tx-2Tx UTS is configured, in which case there can be one UL (or one UL band in the case of intra-band) configured with uplinkTxSwitching.

[0092] When the UE indicates the capability for UL switching of a band combination and the band combination is configured to a serving cell of MCG using E-UTRA radio access and SCG using NR radio access, UL CA, or two UL carriers with a higher layer (e.g., RRC) parameter supplementaryUplink, a switching gap may exist under certain conditions. For example, the following table is taken from 3GPP TS 38.214 V17.1.0 and illustrates the UTS conditions.

[0093] When a UL switching is triggered for a UL transmission starting at T0 (which is within T0-T offset After T0-T1), the UE is not expected to perform the following operations: cancel UL switching, or offset Any other UL transmission scheduled thereafter triggers any other new UL switching that occurs before T0, where T offset It may be the UE processing time defined for UL transmission triggered switching (e.g., see S5.3, S5.4, S6.2.1 and S6.4 of 3GPP TS 38.214 and S9 of 3GPP TS 38.213). It is not expected that the UE will UL =max(u UL,1 ,u UL,2 ) timeslot, where u UL,1 corresponds to the subcarrier spacing of the active UL BWP of one UL carrier before the switching gap, and u UL,2 The subcarrier spacing corresponding to the active ULBWP of another UL carrier after the switching gap.

[0094] [Table 5]

[0095]

[0096]

[0097] [Table 6]

[0098]

[0099]

[0100] [Table 7]

[0101]

[0102] NR supports wide spectrum across various frequency ranges. Due to the reuse of frequency bands originally used in previous generation cellular networks, it is expected that the availability of spectrum will be increased in the 5G advanced market. Especially for low-frequency FR1 bands, available spectrum blocks tend to be more segmented and more dispersed over narrower bandwidths. For FR2 bands and some FR1 bands, multi-carrier operation within the band is required because the available spectrum is to be widened. In order to meet different spectrum requirements, it is important to provide higher throughput and sufficient coverage in the network by using these dispersed spectrum bands or wider bandwidth spectrum in a more spectrum / power efficient and flexible manner. For multi-carrier UL operation, the current specification has several restrictions. For example, a 2TX UE can be configured with up to two UL bands to be changed only by RRC reconfiguration, and UL Tx switching can be performed only between two UL bands for 2Tx UEs. Instead of RRC-based cell reconfiguration, dynamically selecting a carrier with UL Tx switching based on, for example, data services, TDD DL / UL configurations, bandwidth of each band, and channel conditions may potentially lead to higher UL data rates, spectrum utilization, and UE capacity.

[0103] For higher UL data rates, spectrum utilization, and UE capacity, UTS between more than two frequency bands is currently considered. In the following, UTS triggering conditions, UTS-related configuration methods, and / or UTS operation methods required for supporting UTS between multiple frequency bands (e.g., three or more frequency bands) according to some implementations of the present specification are described.

[0104] In the following, the cell may be interpreted according to the context. For example, a cell may represent a serving cell. A cell may include one DL component carrier (CC) and 0 to 2 UL CCs, but the implementation of this specification described below is not limited to this. In the following, unless otherwise specified, the terms cell and CC may be used interchangeably. In some implementations of this specification, a cell / CC may be replaced by an (active) BWP within a serving cell. Unless otherwise specified, in the implementation of this specification described below, a cell / CC may be used as a concept covering PCell, SCell, PsCell, etc., which may be configured / expressed in a carrier aggregation (CA) / dual connection (DC) scenario.

[0105] In the following, the term "band" refers to a frequency band, and the term "band" can be used interchangeably with the term "carrier" and / or "cell" within a band. In this case, each band may include one carrier or multiple (e.g., two) contiguous (or non-contiguous) carriers. The proposed method described below can be applied to inter-band UL CA, intra-band UL CA, NR-DC, EN-DC, (standalone) SUL scenarios, and related band combinations (unless otherwise specified).

[0106] To facilitate description in the implementation of the present specification described below, the following symbols are used.

[0107] -When UTS occurs, it can be expressed as UTS triggering.

[0108] - Frequency band (or carrier) associated with UTS: This may refer to the frequency band / carrier before and after UTS occurs.

[0109] -The Tx chain switching time caused by UTS is expressed as a UTS gap (or UTS period). During the UTS gap, no UL transmission occurs in the frequency band / carrier associated with the UTS. The UTS gap (switching gap) and the UTS period (switching period) can be specifically distinguished as follows:

[0110] ■Switching period: The switching time reported by the UE. Basically, this is a band pair unit including two bands and is reported as one of the values ​​of {35us, 140us and 210us}. For specific switching cases, a single value may be reported as a band combination unit including three or more bands. In this specification, it may also be expressed as UTS period / time or switching period.

[0111] ■ Switching gap: Due to this, the duration of UL transmissions in all (or some) bands associated with a single UL Tx switching event. The switching gap can be determined as the switching period for the corresponding Tx switching (reported by the UE) or by using the switching period for each band pair associated with the corresponding Tx switching.

[0112] For example, for A(1T)+B(1T)->C(2T) switching, where transmission occurs using 2 Tx chains on band C, while 1 Tx chain is connected to band A and 1 Tx chain is connected to band B, if the UE reports the band combination {A+B, C}, the switching gap is determined as the reported value. If not reported, the switching gap may be determined as a value derived using the switching period AB (period_AB) of the band pair including band A and band B and the switching period AC (period_AC) of the band pair including band A and band C. In this specification, it may also be expressed as a UTS gap / interval or a switching interval.

[0113] - A 1Tx chain can be represented as 1T, and a 2Tx chain can be represented as 2T.

[0114] - 1-port UL transmission may be denoted as 1p, and 2-port UL transmission may be denoted as 2p.

[0115] - When 1 Tx chain or 2 Tx chains are connected to a specific frequency band A (and / or a carrier belonging to frequency band A), these states can be represented as A(1T) and A(2T), respectively.

[0116] - When 1 Tx chain is connected to each of two specific bands A (and / or carriers belonging to band A) and band B (and / or carriers belonging to band A), the state may be represented as A(1T)+B(1T).

[0117] -UL transmission can refer to any UL channel or UL signal supported by NR.

[0118] - "Previous transmission" may refer to the most recent UL transmission performed by the UE before the UTS trigger, and "Current transmission" may refer to the UL transmission performed by the UE immediately (or simultaneously) with the UTS trigger. The term "transmission" hereinafter may refer to "UL transmission".

[0119] - The expression that UL transmission occurs may mean UL transmission scheduled via DCI for UL grant and / or UL transmission configured via higher layer signaling (eg, RRC signaling) (eg, configuration of grant UL transmission).

[0120] - When 1-port UL transmission occurs in a specific frequency band A (and / or a carrier belonging to frequency band A), it can be expressed as A(1p), and when 2-port UL transmission occurs, it can be expressed as A(2p).

[0121] - When 1-port UL transmission occurs in two specific frequency bands, for example, frequency band A and frequency band B (and / or carriers belonging to the corresponding frequency bands), it can be expressed as A(1p)+B(1p).

[0122] The RRC parameter uplinkTxSwitchingOption provided by the BS to the UE may indicate which option is configured for dynamic UL Tx switching of inter-band UL CA or (NG) EN-DC. This RRC parameter is configured as switchedUL when the network configures option 1, and is configured as dualUL when the network configures option 2. When the UE receives the corresponding RRC value configured as "switchedUL", the UE does not expect / perform 1 Tx chain to be connected to each of the corresponding two bands, or does not expect / perform concurrent transmission (instruction / configuration) on the corresponding two bands, even if 1 Tx chain is connected to each of the two bands. In the following, this is represented as the configured option 1 operation. For example, a UE configured with switchedUL may not expect to indicate / configure concurrent transmission of A(1T) and B(1T), and the BS may not indicate / configure concurrent transmission of A(1T) and B(1T) to the UE. When the UE receives the corresponding RRC value configured as "dualUL", the UE may expect to schedule / configure (or perform) concurrent transmission on the corresponding two frequency bands via 1 Tx chain connected to each of the two frequency bands, and this is represented as option 2 operation configured below.

[0123] The Tx chain can also be denoted as Tx or transmitter.

[0124] In the case where four frequency bands / carriers are configured (or activated), some implementations of the present specification described below are described based on UTS generation between two frequency bands. However, the same method as the implementation of the present specification described below can also be applied to UTS that occurs when a smaller number of frequency bands (e.g., 3) are configured / activated. The same method as the implementation of the present specification described below can also be applied to UTS that occurs when a larger number of frequency bands (e.g., 5) are configured / activated.

[0125] Some implementations of the present specification described below are described without distinguishing between 1Tx-2Tx switching and 2Tx-2Tx switching. However, some implementations may be particularly applicable to 1Tx-2Tx switching and / or 2Tx-2Tx switching.

[0126] In some implementations of the present specification described below, "simultaneous transmission" in multiple frequency bands may mean that the start time (e.g., start symbol) of the UL transmission in each of the multiple frequency bands coincides and / or some (or all) of the UL transmission resources / time periods in each of the multiple frequency bands overlap in time.

[0127] In the present specification, the symbols "-", "■", "◆", and "●" listed at the front of the paragraph may indicate the vertical / horizontal relationship between the descriptions in each paragraph. Specifically, it may represent a higher category in the order of "-", "■", "◆", and "●". For example, the "■" stated after the "-" may be an additional explanation for the "-". The "◆" after the "■" may be an additional explanation for the "■". The "●" after the "◆" may be an additional explanation for the "◆".

[0128] [0] Description of general operations

[0129] Section [0] summarizes the handling method for the case where it is not possible to uniquely determine the state of the Tx chain after UL Tx switching is triggered due to 1-port UL transmission between two bands.

[0130] In conventional 3GPP Rel-17, UL Tx switching may be configured / defined in the following three cases, as shown in Table 8 below.

[0131] [Table 8]

[0132]

[0133] - In Table 8, "Number of Tx Chains" indicates a state in which a Tx chain is connected to each of two bands. If two Tx chains are connected to a band, it is represented as "2T". If one Tx chain is connected, it is represented as "1T", and if no Tx chain is connected, it is represented as "0T". For example, "1T+1T" in case 1 means that one Tx chain is connected to band A and band B. "2T+0T" in case 2 means that two Tx chains are connected only to band A.

[0134] - In Table 8, "the number of antenna ports for UL transmission" refers to the number of antenna ports for UL transmission on each of the two frequency bands. If 2 antenna ports are used for UL transmission on a frequency band, it is represented as "2P". If 1 antenna port is used for UL transmission, it is represented as "1P", and if no UL transmission occurs, it is represented as "0P". For example, "1P+1P" in case 1 means that 1-port UL transmission occurs on band A and band B. "1P+0P" in case 1 means that 1-port UL transmission occurs only on band A. "0P+1P" means that 1-port UL transmission occurs only on band B.

[0135] - In Table 8, when the state of the Tx chain is the same as Case 1, if "1P+1P" occurs on Band A and Band B, UL Tx switching is not triggered. In addition, if "2P+0P" occurs in Case State 2, or if "0P+2P" occurs in Case State 3, UL Tx switching is not triggered.

[0136] - In Table 8, when the state of the Tx chain is the same as in Case 1, if "2P+0P" (or "0P+2P") occurs, UL Tx switching is triggered, and the Tx chain of Band B (or Band A) is switched to Band A (or Band B). In addition, in the Case 2 state, if "1P+1P" occurs, UL Tx switching is triggered, and one Tx chain of Band A is switched to Band B. In the Case 2 state, if "0P+2P" occurs, UL Tx switching is triggered, and both Tx chains of Band A are switched to Band B.

[0137] - In Table 8, when the state of the Tx chain is the same as Case 1, if "1P+0P" occurs or if "0P+1P" occurs, UL Tx switching may not be triggered. This is because, in the Case 1 state, one Tx chain is connected to Band A and Band B, so even if UL Tx switching does not occur, UL transmission corresponding to "1P+0P" and / or "0P+1P" is possible.

[0138] In addition, in the case 2 state of Table 8, if 1-port UL transmission occurs on band B, UL Tx switching may be triggered. However, if two Tx chains connected to band A are switched to band B, the state changes to case 3. If only one Tx chain is switched to band B, the state may change to case 1. That is, when 1-port UL transmission occurring on band B triggers UL Tx switching, the state after UL Tx switching is not uniquely determined. As a similar example, when 1-port UL transmission occurs on band A in the case 3 state of Table 8, the state after UL Tx switching may be case 1 or case 2.

[0139] To solve this problem, conventional 3GPP Rel-17 has introduced the RRC parameter uplinkTxSwitching-DualUL-TxState. When the RRC configuration value is set to "oneT", the UE can be configured to switch to case 1. When the RRC configuration value is set to "twoT", the UE can be configured to switch to case 2 or case 3. Therefore, the state of the Tx chain can be uniquely determined after UL Tx switching.

[0140] [1] Issues in the three frequency bands

[0141] Section [1] explains the following problem: after UL Tx switching is triggered due to 1-port UL transmission among three bands, it is impossible to uniquely determine the state of the Tx chain.

[0142] When UL Tx switching is configured among three frequency bands, UL Tx switching may be configured / defined in the following six cases, as shown in Table 9.

[0143] [Table 9]

[0144]

[0145] All symbols are the same as in Table 8 except that the relevant frequency bands are added to Band A, Band B, and Band C.

[0146] In this case, the problem of not uniquely determining the state of the Tx chain after UL Tx switching may still occur. For example, in the case 1 state, if 1-port UL transmission occurs on band C, the state of the Tx chain after UL Tx switching can be case 2, case 3, or case 6.

[0147] In addition, even if the conventional RRC parameter uplinkTxSwitching-DualUL-TxState is used, the problem cannot be solved. In the above example, if the RRC parameter is set to "twoT", the Tx chain switches to case 6. However, if the RRC parameter is set to "oneT", the state of the Tx chain after UL Tx switching can be case 2 or case 3.

[0148] In Table 9, for specific cases, when the value of “the number of antenna ports for UL transmission” is the same, Case X can be considered as this problem (for example, Case 1 / Case 3 / Case 4 for “1P+0P+0P”, Case 1 / Case 2 / Case 5 for “0P+1P+0P”, or Case 2 / Case 3 / Case 6 for “0P+0P+1P”).

[0149] [2] Problems in the four frequency bands

[0150] Section [2] explains the following problem: after UL Tx switching is triggered due to 1-port UL transmission between four bands, it is impossible to uniquely determine the state of the Tx chain.

[0151] When UL Tx switching is configured among four frequency bands, UL Tx switching may be configured / defined in the following ten cases, as shown in Table 10.

[0152] [Table 10]

[0153]

[0154] All symbols are the same as in Table 8 and Table 9 except that the relevant frequency bands are added to Band A, Band B, Band C, and Band D.

[0155] In this case, the problem of not uniquely determining the state of the Tx chain after UL Tx switching may still occur. For example, in the case 1 state, if 1-port UL transmission occurs on band C, the state of the Tx chain after UL Tx switching can be case 2, case 3, case 5, or case 9.

[0156] In addition, even if the conventional RRC parameter uplinkTxSwitching-DualUL-TxState is used, the problem cannot be solved. In the above example, if the RRC parameter is set to "twoT", the Tx chain switches to case 9. However, if the RRC parameter is set to "oneT", the state of the Tx chain after UL Tx switching can be case 2, case 3, or case 5.

[0157] In Table 10, for specific cases, in a case where the value of “the number of antenna ports for UL transmission” is the same, Case X can be considered as this problem (for example, Case 1 / Case 4 / Case 5 / Case 7 “1P+0P+0P+0P”, Case 1 / Case 2 / Case 6 / Case 8 for “0P+1P+0P+0P”, Case 2 / Case 3 / Case 5 / Case 9 for “0P+0P+1P+0P” or Case 3 / Case 4 / Case 6 / Case 10 for “0P+0P+0P+1P”).

[0158] [3] The proposed method

[0159] Regarding UL Tx switching across three or four frequency bands mentioned in sections [1] and [2], section [3] proposes a solution to the following problem: after UL Tx switching is triggered due to 1-port UL transmission, the state of the Tx chain cannot be uniquely determined.

[0160] In the proposed method described later, Band A, Band B, Band C, and Band D are not terms referring to specific bands, but can be understood as any band in which UL Tx switching is configured. In addition, Band A, Band B, Band C, and Band D can be understood as the bands mentioned in Tables 9 and 10 of Sections [1] and [2].

[0161] In the following method, when a specific frequency band in which the Tx chain is to be located or switched is configured by RRC, the specific frequency band may be the same as the frequency band in which 1-port UL transmission is scheduled. For example, in the case where there are no two Tx chains on band A, if 1-port UL transmission is scheduled on band A and UL Tx switching is triggered, one of the two Tx chains of the UE may be moved to band A, and the other may be moved to a specific frequency band (band Z). In this case, band Z may be configured for each band by RRC, and band Z may also be set to band A.

[0162] In the following method, when a specific band in which a Tx chain is to be located or switched is configured by RRC, the specific band may be one of the bands having a dualUL relationship with the band in which 1-port UL transmission is scheduled. For example, in the case where there are no two Tx chains on band A, if 1-port UL transmission is scheduled on band A and UL Tx switching is triggered, one of the two Tx chains of the UE may be moved to band A, and the other may be moved to a specific band (band Z). In this case, band Z may be set for each band by RRC. Band Z may be one of the bands having a dualUL relationship with band A. The UE may not expect that the band having a switchedUL relationship with band A will be set to band Z. Alternatively, in the case where there are no two Tx chains on band A, when the band having a switchedUL relationship with band A is set to band Z, if 1-port UL transmission is scheduled on band A and UL Tx switching is triggered, the two Tx chains may be moved to band A.

[0163] [3-1] In the case where two Tx chains exist on a specific band (e.g., band A) and 1-port UL transmission occurs only on a band other than band A (i.e., band X), the following methods may be applied. Specifically, at least one of the methods (or a combination of two or more methods) may be applied.

[0164] -Method 1: As the state of the Tx chain after UL Tx switching, the UE assumes that the two Tx chains are located on the frequency band (=X). In other words, in the case where the situation that may occur after UL Tx switching is not the only one, as mentioned in sections [1] and [2], the UE changes to a state where the two Tx chains are connected to the frequency band X.

[0165] -Method 2: As the state of the Tx chain after UL Tx switching, the UE assumes that one Tx chain is located on the frequency band (=X) and the other Tx chain is located on the frequency band (=A) where the two Tx chains previously existed. In other words, in the case where the situation that may occur after UL Tx switching is not unique, as mentioned in sections [1] and [2], the UE changes to the following state: one Tx chain is connected to frequency band A (in frequency band A, the two Tx chains were connected before UL Tx switching), and the other Tx chain is connected to frequency band X (in frequency band X, 1-port UL transmission occurs).

[0166] -Method 3: As the state of the Tx chain after UL Tx switching, the UE assumes that one Tx chain is located on the frequency band (=X) and the other Tx chain is located on a specific frequency band. In other words, in the case where the situation that may occur after UL Tx switching is not unique, as mentioned in sections [1] and [2], the UE changes to the following state: one Tx chain is connected to the frequency band X (in the frequency band X, 1-port UL transmission occurs), and the other Tx chain is connected to the specific frequency band.

[0167] ■ In this case, the specific frequency band can be determined as follows.

[0168] ◆ Option 1: A specific frequency band is predefined. The specific frequency band may be determined as a frequency band having the lowest or highest cell / carrier index among frequency bands excluding frequency band X. Alternatively, the specific frequency band may be determined as a frequency band having the lowest or highest frequency among frequency bands excluding frequency band X.

[0169] ◆Option 2: A specific frequency band can be configured through a separate RRC.

[0170] In this case, the specific frequency band may be one of the frequency bands having a dual UL relationship with the frequency band in which 1-port UL transmission is scheduled.

[0171] ◆ Option 3: When 1-port UL transmission on band X is scheduled by DCI, the specific band may be configured / indicated by the corresponding DCI.

[0172] - Method 4: Use (reuse) the conventional 3GPP Rel-17 RRC parameter "uplinkTxSwitching-DualUL-TxState".

[0173] ■ Option-1: When "uplinkTxSwitching-DualUL-TxState" is set to "twoT", UL Tx switching is performed according to method 1 so that the two Tx chains are located on band X where 1-port UL transmission occurs. When "uplinkTxSwitching-DualUL-TxState" is set to "oneT", UL Tx switching is performed according to method 2 so that one Tx chain is located on band A to which the two Tx chains were connected before UL Tx switching, and the other Tx chain is located on band X where 1-port UL transmission occurs.

[0174] ■ Option-2: When "uplinkTxSwitching-DualUL-TxState" is set to "twoT", UL Tx switching is performed according to method 1 so that two Tx chains are located on frequency band X where 1-port UL transmission occurs. When "uplinkTxSwitching-DualUL-TxState" is set to "oneT", UL Tx switching is performed so that one Tx chain is located on a specific frequency band determined according to method 3 and the other Tx chain is located on frequency band X where 1-port UL transmission occurs.

[0175] ◆In this case, if simultaneous UL transmission does not occur on the specific frequency band determined according to Method 3 and frequency band X where 1-port UL transmission occurs, or if the configuration or report does not allow simultaneous UL transmission on two frequency bands, the UE can perform UL Tx switching so that the two Tx chains are located on frequency band X.

[0176] ◆Alternatively, if simultaneous UL transmission does not occur on the specific frequency band determined according to method 3 and the frequency band X where 1-port UL transmission occurs, or if the configuration or report does not allow simultaneous UL transmission on two frequency bands, the UE may perform UL Tx switching according to the RRC configuration proposed in option-3 or the RRC configuration proposed in option-3 of method 4 in [3-2] so that one Tx chain is located on frequency band X and the other Tx chain is located on one of the frequency bands where simultaneous transmission with frequency band X is possible.

[0177] ◆ Alternatively, in this case, the UE may not desire to schedule 1-port UL transmission on Band X.

[0178] ◆ In this case, the specific frequency band configured for each frequency band by the RRC configuration proposed in option-3 or the RRC configuration proposed in option-3 of method 4 in [3-2] or the specific frequency band determined according to method 3 may be the same as the frequency band X in which 1-port UL transmission occurs. In this case, even if only 1-port UL transmission is scheduled on frequency band X, the UE may perform UL Tx switching so that both Tx chains are located on frequency band X.

[0179] ■Option-3: When "uplinkTxSwitching-DualUL-TxState" is set to "twoT", UL Tx switching is performed according to Method 1 so that the two Tx chains are located on band X where 1-port UL transmission occurs. When "uplinkTxSwitching-DualUL-TxState" is set to "oneT", UL Tx switching is performed so that the Tx chains are located on one or two specific frequency bands. In this case, the specific one or two frequency bands can be configured by a separate RRC (called "UTS-TxState-Ext-1"). "UTS-TxState-Ext-1" can configure / indicate one of the combinations of one frequency band where the two Tx chains are located or two frequency bands with one Tx chain per frequency band, which can be determined by Method 1, Method 2 and / or Method 3.

[0180] ■In this case, the specific frequency band for band X configured / indicated by “UTS-TxState-Ext-1” may be a frequency band (which is band X) in which 1-port UL transmission occurs. That is, when 1-port UL transmission occurs on band X, if two Tx chains are located on band Y_0 (where Y_0 is a frequency band different from X), if the switching option is set to “dualUL”, and if “uplinkTxSwitching-DualUL-TxState” is set to “oneT”, one of the Tx chains located on band Y_0 may switch to band X, and the other may switch to the specific frequency band configured / indicated by “UTS-TxState-Ext-1”. If the specific frequency band for band X is configured / indicated as band X by “UTS-TxState-Ext-1”, both Tx chains of the UE may switch to band X even if “uplinkTxSwitching-DualUL-TxState” is set to “oneT”.

[0181] Option-3 can be summarized as follows. Whether to perform UL Tx switching so that both Tx chains are located on the frequency band X where 1-port UL transmission occurs, or whether to perform UL Tx switching so that one Tx chain is located on the frequency band X where 1-port UL transmission occurs and the other Tx chain is located on another specific frequency band can be configured through RRC (in this case, the specific frequency band can also be configured).

[0182] The RRC configuration in method 3 or method 4 may configure a specific frequency band for each frequency band configured for the UE (or for each frequency band for which UL Tx switching is configured).

[0183] For example, for three bands, a specific band for band A may be set to band B, a specific band for band B may be set to band C, and a specific band for band C may be set to band A. In this configuration, when there are two Tx chains on band A and 1-port UL transmission occurs on band B, one Tx chain may be switched to band B, and the other Tx chain may be switched to band C. Alternatively, if 1-port UL transmission occurs on band C, one Tx chain may be switched to band C, and the other Tx chain may remain on band A.

[0184] In this case, the specific frequency band configured for each frequency band may be one of the frequency bands for which simultaneous UL transmission is configured or reported.

[0185] Alternatively, the specific frequency band configured for each frequency band may be the same as each frequency band. In this case, if UL transmission occurs on the corresponding frequency band and the Tx chain needs to be switched to the corresponding frequency band, the UE may switch both Tx chains to the corresponding frequency band even if the scheduled UL transmission on the corresponding frequency band is a 1-port UL transmission. Alternatively, in this case, the UE may not expect to schedule a 1-port UL transmission on the corresponding frequency band.

[0186] If there are no other frequency bands available for simultaneous transmission with a given frequency band (= frequency band X1), the BS may not configure a specific frequency band for frequency band X1. When UL transmission occurs on frequency band X1 and the Tx chain needs to be switched to frequency band X1, the UE may switch both Tx chains to frequency band X1 even if the scheduled UL transmission on frequency band X1 is a 1-port UL transmission. Alternatively, in this case, the UE may not desire to schedule a 1-port UL transmission on frequency band X1.

[0187] The above RRC configuration may be the same as the RRC configuration proposed in [3-2] (e.g., Option 2 of Method 3 in [3-2]). Alternatively, the above RRC configuration may be used for a scenario where two Tx chains exist on a specific band (e.g., Band A), and may not be applicable to a scenario where one Tx chain exists on each of two specific bands (e.g., Band A and Band B), which is proposed in [3-2].

[0188] [3-2] In a scenario where there is one Tx chain on each of two specific frequency bands (e.g., band A and band B), if 1-port UL transmission occurs only on a frequency band (band Y) other than band A or band B, the following methods may be applied. Specifically, at least one of the methods or a combination of two or more methods may be applied.

[0189] -Method 1: As the state of the Tx chain after UL Tx switching, the UE assumes that the two Tx chains are located on the frequency band (=Y). In other words, in the case that the situation that may occur after UL Tx switching is not the only one, as mentioned in sections [1] and [2], the UE changes to a state where the two Tx chains are connected to the frequency band Y.

[0190] - Method 2: As the state of the Tx chain after UL Tx switching, the UE assumes that one Tx chain is located on a frequency band (=Y) and the other Tx chain is located on a specific frequency band (frequency band A or frequency band B) to which the previous Tx chain is connected among the frequency bands. In other words, in the case where the situation that may occur after UL Tx switching is not the only one, as mentioned in sections [1] and [2], the UE changes to a state where one Tx chain is connected to a specific frequency band to which the previous Tx chain is connected among the frequency bands and the other Tx chain is connected to frequency band Y where 1-port UL transmission occurs. In this case, the specific frequency band between frequency band A and frequency band B can be determined by a separate RRC configuration or by a predefined rule.

[0191] ■Examples of predefined rules:

[0192] ◆ Select from band A and band B a band having a cell / carrier having the lowest or highest index among cells / carriers in each band.

[0193] ◆Select a frequency band having a smaller frequency gap with frequency band Y from among frequency band A and frequency band B.

[0194] ◆Select the band in which the most recent UL transmission was performed before the 1-port UL transmission on band Y from band A and band B.

[0195] ◆A frequency band for UL transmission configured by higher layer signaling setting such as RRC signaling is selected from frequency band A and frequency band B.

[0196] -Method 3: As the state of the Tx chain after UL Tx switching, the UE assumes that one Tx chain is located on the frequency band (=X) and the other Tx chain is located on the specific frequency band. In other words, in the case where the situation that may occur after UL Tx switching is not unique, as mentioned in sections [1] and [2], the UE changes to a state in which one Tx chain is connected to the frequency band Y where 1-port UL transmission occurs and the other Tx chain is connected to the specific frequency band.

[0197] ■ In this case, the specific frequency band can be determined as follows.

[0198] ◆ Option 1: The specific frequency band is predefined. The specific frequency band may be determined as the frequency band with the lowest or highest cell / carrier index among the frequency bands excluding frequency band Y. Alternatively, the specific frequency band may be determined as the frequency band with the lowest or highest frequency among the frequency bands excluding frequency band Y.

[0199] ◆Option 2: A specific frequency band can be configured through a separate RRC.

[0200] ◆ Option 3: When 1-port UL transmission on frequency band Y is scheduled by DCI, a specific frequency band may be configured / indicated by the corresponding DCI.

[0201] - Method 4: Use (reuse) the conventional 3GPP Rel-17 RRC parameter "uplinkTxSwitching-DualUL-TxState".

[0202] ■ Option-1: When "uplinkTxSwitching-DualUL-TxState" is set to "twoT", UL Tx switching is performed according to method 1 so that two Tx chains are located on band Y where 1-port UL transmission occurs. When "uplinkTxSwitching-DualUL-TxState" is set to "oneT", UL Tx switching is performed so that one Tx chain is located on the band determined according to method 2 and the other Tx chain is located on band Y where 1-port UL transmission occurs.

[0203] ■ Option-2: When "uplinkTxSwitching-DualUL-TxState" is set to "twoT", UL Tx switching is performed according to method 1 so that two Tx chains are located on frequency band Y where 1-port UL transmission occurs. When "uplinkTxSwitching-DualUL-TxState" is set to "oneT", UL Tx switching is performed so that one Tx chain is located on a specific frequency band determined according to method 3 and the other Tx chain is located on frequency band Y where 1-port UL transmission occurs.

[0204] ■Option-3: When "uplinkTxSwitching-DualUL-TxState" is set to "twoT", UL Tx switching is performed according to Method 1 so that the two Tx chains are located on band Y where 1-port UL transmission occurs. When "uplinkTxSwitching-DualUL-TxState" is set to "oneT", UL Tx switching is performed so that the Tx chains are located on one or two specific frequency bands. In this case, the specific one or two frequency bands can be configured by a separate RRC (called "UTS-TxState-Ext-2"). "UTS-TxState-Ext-2" can configure / indicate one of the combinations of one frequency band where the two Tx chains are located or two frequency bands with one Tx chain per frequency band, which can be determined by Method 1, Method 2 and / or Method 3.

[0205] ■ In this case, the specific band for band X configured / indicated by "UTS-TxState-Ext-1" may be the band in which 1-port UL transmission occurs (which is band X). That is, when 1-port UL transmission occurs on band X, if two Tx chains are located on bands Y_1 and Y_2 (where Y_1 and Y_2 are bands different from band X), if the switching option is set to "dualUL" and if "uplinkTxSwitching-DualUL-TxState" is set to "oneT", one Tx chain located on band Y_1 or Y_2 may be switched to band X, and the other Tx chain located on band Y_2 or Y_1 may be switched to the specific band configured / indicated by "UTS-TxState-Ext-1". If a specific band for band X is configured / indicated as band X through “UTS-TxState-Ext-1”, both Tx chains of the UE may be switched to band X even if “uplinkTxSwitching-DualUL-TxState” is set to “oneT”.

[0206] Option-3 can be summarized as follows. Whether to perform UL Tx switching so that both Tx chains are located on the frequency band Y where 1-port UL transmission occurs, or whether to perform UL Tx switching so that one Tx chain is located on the frequency band Y where 1-port UL transmission occurs and the other Tx chain is located on another specific frequency band can be configured through RRC (in this case, the specific frequency band can also be configured).

[0207] The RRC configuration in method 3 or method 4 may configure a specific frequency band for each frequency band configured for the UE (or for each frequency band for which UL Tx switching is configured).

[0208] For example, for four bands, a specific band for band A may be set to band B, a specific band for band B may be set to band C, a specific band for band C may be set to band D, and a specific band for band D may be set to band A. In this configuration, when one Tx chain is on band A and the other Tx chain is on band B, if 1-port UL transmission occurs on band C, one Tx chain may be switched to band C, and the other Tx chain may be switched to band D. Alternatively, if 1-port UL transmission occurs on band D, one Tx chain may be switched to band D, and the other Tx chain may remain on band A.

[0209] In this case, the specific frequency band configured for each frequency band may be one of the frequency bands for which simultaneous UL transmission is configured or reported.

[0210] Alternatively, the specific frequency band configured for each frequency band may be the same as each frequency band. In this case, if UL transmission occurs on the corresponding frequency band and the Tx chain needs to be switched to the corresponding frequency band, the UE may switch both Tx chains to the corresponding frequency band even if the scheduled UL transmission on the corresponding frequency band is a 1-port UL transmission. Alternatively, in this case, the UE may not expect to schedule a 1-port UL transmission on the corresponding frequency band.

[0211] If there are no other frequency bands available for simultaneous transmission with a given frequency band (= frequency band X1), the BS may not configure a specific frequency band for frequency band X1. When UL transmission occurs on frequency band X1 and the Tx chain needs to be switched to frequency band X1, the UE may switch both Tx chains to frequency band X1 even if the scheduled UL transmission on frequency band X1 is a 1-port UL transmission. Alternatively, in this case, the UE may not desire to schedule a 1-port UL transmission on frequency band X1.

[0212] The above RRC configuration may be the same as the RRC configuration proposed in [3-1] (e.g., Option 2 of Method 3 in [3-1]). Alternatively, the above RRC configuration may be used for a scenario where one Tx chain exists on each of two specific frequency bands (e.g., Band A and Band B), and may not be applicable to a scenario where two Tx chains exist on a specific frequency band (e.g., Band A), which is proposed in [3-1].

[0213] [3-3] By combining one or more of the methods proposed in [3-1] and one or more of the methods proposed in [3-2], UL Tx switching operation can be configured for three or four frequency bands.

[0214] - For example, when 1-port UL transmission occurs on band Z in addition to band A, if the state of the Tx chains before UL Tx switching is that both Tx chains are on band A, UL Tx switching may be performed according to method 2 in [3-1] so that one Tx chain is on band A and the other Tx chain is on band Z. If the state of the Tx chains before UL Tx switching is that one Tx chain is on band A and the other Tx chain is on band B, UL Tx switching may be performed according to method 1 in [3-2] so that both Tx chains are on band Z.

[0215] - As another example, when 1-port UL transmission occurs on band Z in addition to band A, if the state of the Tx chains before UL Tx switching is that both Tx chains are on band A, UL Tx switching may be performed according to method 2 in [3-1] so that one Tx chain is on band A and the other Tx chain is on band Z. If the state of the Tx chains before UL Tx switching is that one Tx chain is on band A and the other Tx chain is on band B, UL Tx switching may be performed according to option 2 of method 3 in [3-2] so that one Tx chain is on a determined band and the other Tx chain is on band Z.

[0216] - As another example, when 1-port UL transmission occurs on band Z in addition to band A, if "uplinkTxSwitching-DualUL-TxState" is set to "twoT", UL Tx switching may be performed so that two Tx chains are located on band Z. If the RRC parameter is set to "oneT", UL Tx switching may be performed so that one Tx chain is located on band Z and the other Tx chain is located on a specific band determined by one of the methods in [3-1] or [3-2].

[0217] [3-4] The proposed methods in [3-1] to [3-3] may be applied only to a specific option (i.e., "switchedUL" or "dualUL") of the "simultaneous transmission option" configured for UL Tx switching. For example, the above proposed methods may be applied only to a band combination for which UL Tx switching is configured such that dualUL is enabled for the UE.

[0218] [3-5] In Rel-17, the RRC parameter uplinkTxSwitching-DualUL-TxState can be set to "oneT" or "twoT" through CellGroupConfig. In addition, the RRC parameter uplinkTxSwitching-DualUL-TxState can be applied to the frequency band configured with dualUL. In this case, the dualUL configuration is also performed through CellGroupConfig. When "oneT" is configured for the frequency band configured with dualUL, if 1-port UL transmission is scheduled on a specific frequency band (which triggers UL Tx switching), after switching, one Tx chain can be located on each of the two frequency bands. If "twoT" is configured, UL Tx switching can be performed so that the two Tx chains are located on the frequency band where 1-port UL transmission is scheduled. In addition, since UL Tx switching between two frequency bands is defined in Rel-17, even if dualUL configuration is performed through CellGroupConfig and uplinkTxSwitching-DualUL-TxState configuration is applied, it can have the same effect as the configuration of a frequency band pair (ie, the configuration of two frequency bands).

[0219] In Rel-18, since UL Tx switching can be performed so that the Tx chain is located on one or two bands out of a maximum of four bands, the number of possible cases for UL Tx switching can vary depending on whether the dualUL configuration is performed by CellGroupConfig or on a band pair basis. In addition, although simultaneous UL transmission between two bands in which dualUL is configured in Rel-17 is always possible, it has not yet been determined whether simultaneous UL transmission between two bands in which dualUL is configured in Rel-18 is always possible. Therefore, considering the cases where dualUL configuration and simultaneous transmission configuration are different, it can be determined whether uplinkTxSwitching-DualUL-TxState is configured at the CellGroupConfig level, the band pair level, or the individual band level.

[0220] (1) If dualUL configuration is performed through CellGroupConfig, and simultaneous transmission is always possible on any band pair (e.g., band combination) within the band where dualUL is configured, uplinkTxSwitching-DualUL-TxState can be configured through CellGroupConfig. In other words, for Rel-18, UL Tx switching, dualUL configuration, simultaneous transmission configuration, and oneT / twoT configuration can all be performed through CellGroupConfig, as in Rel-17.

[0221] (2) If dualUL configuration is performed through CellGroupConfig, and if simultaneous transmission configuration for any band pair (eg, band combination) within the band in which dualUL is configured is determined through a separate RRC, Alt-1 or Alt-2 may be possible.

[0222] -Alt-1: uplinkTxSwitching-DualUL-TxState can be configured through CellGroupConfig.

[0223] -Alt-2: uplinkTxSwitching-DualUL-TxState can be configured based on band pairs.

[0224] When Alt-1 is applied, a specific band pair can be configured so that even if dualUL and oneT (for a band combination including the bands) are configured, simultaneous transmission is not allowed. In this case, the RRC configuration method described in [3-1] to [3-5] can be applied. For example, when UL Tx switching is configured for three bands: Band A / Band B / Band C, and when dualUL and oneT are configured for Band A / Band B / Band C, it can be considered that simultaneous transmission is allowed or not allowed on Band A and Band B.

[0225] -When simultaneous transmission is allowed,

[0226] ■ If there are two Tx chains on band A and 1-port UL transmission is scheduled on band B, the state can be changed so that one Tx chain is on band A and the other Tx chain is on band B after UL Tx switching because "oneT" is configured.

[0227] -When simultaneous transmission is not allowed,

[0228] If there are two Tx chains on band A and 1-port UL transmission is scheduled on band B, since there is no state in which one Tx chain is located on band A and the other Tx chain is located on band B, the state may not be changed so that even if 'oneT' is configured, one Tx chain is located on each of band A and band B. Therefore, in this case, the UE may operate as follows.

[0229] ◆ Option 1) Even if "oneT" is configured, in this case, the UE can operate exceptionally so that both Tx chains are on Band B. Alternatively,

[0230] ◆Option 2) (as mentioned in the proposed method above) by pre-configuring a specific frequency band for band B (preferably, a frequency band capable of simultaneous transmission with band B), the UE can operate so that one Tx chain is located on the pre-configured specific frequency band and the other Tx chain is located on band B (if 1-port transmission from two Tx chains on band A (where simultaneous transmission is not allowed) to band B is required). Alternatively,

[0231] ◆Option 3) When there are two Tx chains on Band A, the UE may not expect to schedule 1-port UL transmission on Band B, where simultaneous transmission with Band A is not possible (if such a scheduling DCI is received, the UE may operate by discarding (ignoring) the DCI.)

[0232] (3) If dualUL configuration is performed based on a band pair, and if simultaneous transmission is always possible on a band pair configured with dual configuration, uplinkTxSwitching-DualUL-TxState can be configured based on a band pair. That is, for Rel-18, UL Tx switching, dualUL configuration, simultaneous transmission configuration, and oneT / twoT configuration can all be configured based on a band pair.

[0233] The content of the present disclosure is not limited to being applied only to UL and / or DL ​​signal transmission and reception. For example, the content of the present disclosure can also be used for direct communication between UEs. In this document, the term base station (BS) can be understood as including the concept of relay node and BS. For example, the operation of the BS described in the present disclosure can be performed by a relay node and a BS.

[0234] Obviously, each example in the examples of the proposed method may also be included as an implementation method of the present disclosure, and therefore each example may be considered as one of the proposed methods. Although the above-mentioned proposed methods may be implemented independently, some of the proposed methods may be combined and implemented. In addition, it may be provided that information on whether to apply the proposed method (or information on rules related to the proposed method) is sent from the BS to the UE in a predefined signal (e.g., physical layer signaling or higher layer signaling).

[0235] Implementation Example

[0236] Figure 5 is a flowchart of a signal sending and receiving method according to an embodiment of the present disclosure.

[0237] Reference Figure 5 According to an embodiment of the present disclosure, the signal transmission and reception method may be performed by a UE. The method may include: configuring at least three UL frequency bands (S501); receiving a first parameter and a second parameter (S503); and performing a second transmission in an operation state capable of supporting the first transmission (S505). Figure 5 The signal sending and receiving method of the BS corresponding to the implementation mode of the present disclosure may include: configuring at least three UL frequency bands for the UE (S501); sending a first parameter and a second parameter (S503); and receiving a second transmission from the UE in an operating state capable of supporting the first transmission (S505).

[0238] The at least three UL frequency bands include at least a first frequency band, a second frequency band, and a third frequency band. Depending on the number of UL frequency bands, additional UL frequency bands from a fourth frequency band to an Nth frequency band may also be included.

[0239] The first transmission is a transmission performed before the UL switching, and the second transmission is a transmission performed after the UL switching. If one or more of the frequency bands in which the first transmission is performed is different from the frequency band in which the second transmission is performed, it is necessary to perform UL switching (UL Tx switching) so that one or more of the two Tx chains of the UE are switched to different frequency bands. For reference, in an embodiment of the present disclosure, it is not necessary to perform the first transmission between the UE and the BS. For any reason, if the position of the Tx chain of the UE is in an operating state capable of supporting the first transmission, the embodiment of the present disclosure can be implemented even if the first transmission is not actually performed. This also applies to the third transmission to be described below.

[0240] The first parameter refers to the RRC parameter uplinkTxSwitching-DualUL-TxState. Referring to conventional 3GPP TS38.331, when the state of the Tx chain after UL switching is not unique, this parameter is used to indicate the stable state of the Tx chain after UL switching. If the value of the parameter indicates one Tx chain (ie, the value of the parameter is "oneT"), the BS and / or UE may assume that after UL switching, the two Tx chains are each connected / located on a carrier of each frequency band. If the parameter is not configured or if the value of the parameter indicates two Tx chains (ie, the value of the parameter is "twoT"), the BS and / or UE may assume that after UL switching, the two Tx chains are connected / located on a carrier of a single frequency band.

[0241] (If the state of the Tx chain after UL Tx switching is not unique when 2Tx-2Tx switching is configured and uplinkTxSwitchingOption is set to dualUL, uplinkTxSwitching-DualUL-TxState indicates the state of the Tx chain. The value oneT indicates that 1Tx is assumed to be supported on the carrier on each frequency band, and the value twoT indicates that 2Tx is assumed to be supported on the carrier.)

[0242] The second parameter is an RRC parameter for configuring a frequency band associated with a frequency band for performing 1-port transmission after UL switching, which may be named “AssociatedBand”.

[0243] Apart from Figure 5 In addition to the operations described in sections [0] to [3], one or more of the operations described in sections [0] to [3] may be performed.

[0244] For example, referring to section [3-2] of this specification, when each of two specific frequency bands has one Tx chain, 1-port UL transmission occurs on the other frequency band. Therefore, according to the example in section [3-2], the first transmission corresponds to 1-port transmission performed on a carrier of each of the first frequency band (or frequency band A) and the second frequency band (or frequency band B). The second transmission corresponds to 1-port transmission performed on a carrier of the third frequency band (or frequency band Y).

[0245] Alternatively, referring to Option-2 of Method 4 in Section [3-2], if the first parameter is set to "oneT", that is, if the first parameter indicates one Tx chain, after UL switching, one Tx chain may be located on a specific frequency band determined according to Method 3, and the other Tx chain may be located on Frequency Band 3 where 1-port UL transmission occurs. Referring to Option 2 of Method 3 in Section [3-2], a specific frequency band is configured through RRC signaling. The specific frequency band corresponds to an associated frequency band, and the RRC signaling for configuring the specific frequency band may include a second parameter. The associated frequency band may be a first frequency band or a second frequency band. In addition, the associated frequency band may be another frequency band excluding the first frequency band to the third frequency band.

[0246] Therefore, the Tx chains located on the first frequency band and the second frequency band before the UL switching are located on the third frequency band and the associated frequency band, respectively, after the UL switching.

[0247] In other words, when the UE is in an operating state capable of supporting 1-port transmission (first transmission) on a carrier of each of the first frequency band and the second frequency band, and when 1-port transmission (second transmission) is performed on a carrier of a third frequency band without any transmission on the first frequency band and the second frequency band (or without transmission on all frequency bands except the third frequency band), if the value of the first parameter indicates one Tx chain and the associated frequency band is configured by the second parameter, the UE can consider performing 1-port transmission on a carrier of each of the third frequency band and the associated frequency band for UL switching.

[0248] (If the UE is configured with uplinkTxSwitching-DualUL-TxState set to "oneT", then when the UE is in the following operating state: it can support 1-port transmission on one carrier on the first band and the second band, followed by no transmission on any carrier on these two bands and 1-port transmission on another carrier on the third band, the UE should consider this as if 1-port transmission is sent on the third band, and the frequency band associated with the third band is configured by AssociatedBand, otherwise the UE should consider this as if 2-port transmission occurs on the transmitting carrier).

[0249] Since the UE performs 1-port transmission on a carrier of each of the third frequency band and the associated frequency band instead of actual second transmission for UL switching consideration, only the Tx chain is switched to the associated frequency band and actual UL transmission does not occur on the carrier of the associated frequency band.

[0250] Therefore, if the UE is configured to consider that 1-port transmission has been performed on a carrier of an associated frequency band, the UE and the BS can clearly recognize the location of a Tx chain that is not used for actual transmission.

[0251] In the above, it has been described that the associated frequency band for the third frequency band is configured by the second parameter. However, when 1-port transmission is first performed on carriers of the first frequency band (or the second frequency band) and the third frequency band, and then 1-port transmission is performed on the second frequency band (or the first frequency band), UL switching also needs to be performed smoothly. Therefore, the second parameter can be used to configure the associated frequency band for each of all frequency bands configured for the UE in relation to UL switching.

[0252] If the first parameter is not configured, or if the first parameter indicates "twoT", i.e., two Tx chains, the two Tx chains located on the first frequency band and the second frequency band, respectively, are switched to the third frequency band. The UE may regard this operation as 2-port transmission performed on a carrier of the third frequency band for UL switching.

[0253] In addition, referring to section [3-1] of this specification, when two Tx chains exist on a specific frequency band, 1-port UL transmission occurs on another frequency band. Therefore, according to the example in section [3-1], the first transmission corresponds to a 2-port transmission performed on a carrier of a first frequency band (or band A). The second transmission corresponds to a 1-port transmission performed on a carrier of a third frequency band (or band X). When the operations of sections [3-1] and [3-2] are combined, the transmission corresponding to one of the sections may be referred to as the first transmission and the second transmission, and the transmission corresponding to the other section may be referred to as the third transmission and the fourth transmission.

[0254] Referring to Option-2 of Method 4 in Section [3-1], if the first parameter is set to "oneT", that is, the first parameter indicates one Tx chain, then after UL switching, one Tx chain may be located on a specific frequency band determined according to Method 3, and the other Tx chain may be located on Frequency Band 3 where 1-port UL transmission occurs. Referring to Option 2 of Method 3 in Section [3-1], a specific frequency band is configured through RRC signaling. The specific frequency band corresponds to an associated frequency band, and the RRC signaling for configuring the specific frequency band may include a second parameter. The associated frequency band may be a first frequency band or a second frequency band. In addition, the associated frequency band may be another frequency band excluding the first frequency band to the third frequency band.

[0255] In other words, when the UE is in an operating state capable of supporting 2-port transmission (first transmission or third transmission) on a carrier of the first frequency band, and when 1-port transmission (second transmission or fourth transmission) is performed on a carrier of the third frequency band without any transmission on the first frequency band (or without transmission on any frequency band except the third frequency band), if the value of the first parameter indicates one Tx chain and the associated frequency band is configured by the second parameter, the UE can consider performing 1-port transmission on a carrier of each of the third frequency band and the associated frequency band for UL switching.

[0256] (If the UE is configured with uplinkTxSwitching-DualUL-TxState set to "oneT", then when the UE is in the following operating state: it can support 2-port transmission on one carrier on one frequency band, followed by no transmission on any carrier on the same frequency band and 1-port transmission on another carrier on another frequency band, the UE should consider this as if 1-port transmission is sent on both uplinks, otherwise the UE should consider this as if 2-port transmission occurs on the transmitting carrier).

[0257] Since the UE considers performing 1-port transmission on the carrier of each of the third frequency band and the associated frequency band instead of the actual second transmission (or fourth transmission) for uplink switching, only the Tx chain is switched to the associated frequency band, and no actual uplink transmission is performed on the carrier of the associated frequency band.

[0258] In addition to about Figure 5 In addition to the operations described, you can also perform additional operations in combination with reference Figures 1 to 4 The operations described and / or one or more of the operations described in sections [1] to [3].

[0259] Example of a communication system to which the present disclosure is applied

[0260] The various descriptions, functions, processes, proposals, methods and / or operational flowcharts of the present disclosure described herein may be applied to, but not limited to, various fields requiring wireless communication / connection between devices (e.g., 5G).

[0261] More specific examples will be described below with reference to the accompanying drawings.In the following drawings / descriptions, unless otherwise specified, the same reference numerals represent the same or corresponding hardware blocks, software blocks or functional blocks.

[0262] Figure 6 A communication system 1 applied to the present disclosure is illustrated.

[0263] refer to Figure 6, the communication system 1 applied to the present disclosure includes a wireless device, a BS, and a network. The wireless device is a device that performs communication using a radio access technology (RAT) (e.g., 5G NR (or new RAT) or LTE), also referred to as a communication / radio / 5G device. The wireless device may include (but is not limited to) a robot 100a, a vehicle 100b-1 and 100b-2, an extended reality (XR) device 100c, a handheld device 100d, a home appliance 100e, an IoT device 100f, and an artificial intelligence (AI) device / server 400. For example, a vehicle may include a vehicle with a wireless communication function, an autonomous driving vehicle, and a vehicle capable of vehicle-to-vehicle (V2V) communication. In this article, a vehicle may include an unmanned aerial vehicle (UAV) (e.g., a drone). The XR device may include an augmented reality (AR) / virtual reality (VR) / mixed reality (MR) device, and may be implemented in the form of a head-mounted device (HMD), a head-up display (HUD) installed in a vehicle, a television (TV), a smart phone, a computer, a wearable device, a home appliance, a digital signage, a vehicle, a robot, etc. Handheld devices may include smart phones, smart boards, wearable devices (e.g., smart watches or smart glasses), and computers (e.g., laptop computers). Home appliances may include TVs, refrigerators, washing machines, etc. IoT devices may include sensors, smart meters, etc. For example, a BS and a network may be implemented as wireless devices, and a specific wireless device 200a may operate as a BS / network node for other wireless devices.

[0264] The wireless devices 100a to 100f may be connected to the network 300 via the BS 200. The AI ​​technology may be applied to the wireless devices 100a to 100f, and the wireless devices 100a to 100f may be connected to the AI ​​server 400 via the network 300. The network 300 may be configured using a 3G network, a 4G (e.g., LTE) network, or a 5G (e.g., NR) network. Although the wireless devices 100a to 100f may communicate with each other via the BS 200 / network 300, the wireless devices 100a to 100f may perform direct communication (e.g., side link communication) with each other without the intervention of the BS / network. For example, the vehicles 100b-1 and 100b-2 may perform direct communication (e.g., V2V / vehicle-to-everything (V2X) communication). An IoT device (e.g., a sensor) may perform direct communication with other IoT devices (e.g., a sensor) or other wireless devices 100a to 100f.

[0265] Wireless communication / connection 150a, 150b and 150c can be established between wireless devices 100a to 100f / BS200 and between BS200. Herein, wireless communication / connection can be established through various RATs (e.g., 5G NR) such as UL / DL communication 150a, side link communication 150b (or D2D communication) or inter-BS communication (e.g., relay or integrated access backhaul (IAB)). Wireless signals can be sent and received between wireless devices, between wireless devices and BSs, and between BSs through wireless communication / connection 150a, 150b and 150c. For example, signals can be sent and received via various physical channels through wireless communication / connection 150a, 150b and 150c. To this end, at least a portion of various configuration information for configuring processes for sending / receiving wireless signals, various signal processing processes (e.g., channel coding / decoding, modulation / demodulation and resource mapping / demapping) and resource allocation processes can be performed based on various proposals of the present disclosure.

[0266] Example of wireless device to which the present disclosure is applied

[0267] Figure 7 A wireless device suitable for use with the present disclosure is shown.

[0268] Reference Figure 7 , the first wireless device 100 and the second wireless device 200 may transmit wireless signals through various RATs (e.g., LTE and NR). {The first wireless device 100 and the second wireless device 200} may correspond to Figure 6 {wireless device 100x and BS 200} and / or {wireless device 100x and wireless device 100x}.

[0269] The first wireless device 100 may include one or more processors 102 and one or more memories 104, and also include one or more transceivers 106 and / or one or more antennas 108. The processor 102 may control the memory 104 and / or the transceiver 106, and may be configured to implement the description, functions, processes, proposals, methods, and / or operation flowcharts disclosed in this document. For example, the processor 102 may process the information in the memory 104 to generate first information / signals, and then transmit a wireless signal including the first information / signals through the transceiver 106. The processor 102 may receive a wireless signal including second information / signals through the transceiver 106, and then store information obtained by processing the second information / signals in the memory 104. The memory 104 may be connected to the processor 102, and may store various information related to the operation of the processor 102. For example, the memory 104 may store software codes including instructions for executing all or part of the processing controlled by the processor 102 or for executing the description, functions, processes, proposals, methods, and / or operation flowcharts disclosed in this document. The processor 102 and the memory 104 may be part of a communication modem / circuit / chip designed to implement a RAT (e.g., LTE or NR). The transceiver 106 may be connected to the processor 102 and transmit and / or receive wireless signals through one or more antennas 108. Each transceiver 106 may include a transmitter and / or a receiver. The transceiver 106 may be used interchangeably with a radio frequency (RF) unit. In the present disclosure, the wireless device may be a communication modem / circuit / chip.

[0270] The second wireless device 200 may include one or more processors 202 and one or more memories 204, and also include one or more transceivers 206 and / or one or more antennas 208. The processor 202 may control the memory 204 and / or the transceiver 206, and may be configured to implement the description, functions, processes, proposals, methods, and / or operation flowcharts disclosed in this document. For example, the processor 202 may process the information in the memory 204 to generate third information / signals, and then transmit a wireless signal including the third information / signals through the transceiver 206. The processor 202 may receive a wireless signal including fourth information / signals through the transceiver 106, and then store information obtained by processing the fourth information / signals in the memory 204. The memory 204 may be connected to the processor 202 and store various information related to the operation of the processor 202. For example, the memory 204 may store software codes including instructions for executing all or part of the processing controlled by the processor 202 or for executing the description, functions, processes, proposals, methods, and / or operation flowcharts disclosed in this document. The processor 202 and the memory 204 may be part of a communication modem / circuit / chip designed to implement a RAT (e.g., LTE or NR). The transceiver 206 may be connected to the processor 202 and transmit and / or receive wireless signals through one or more antennas 208. Each transceiver 206 may include a transmitter and / or a receiver. The transceiver 206 may be used interchangeably with an RF unit. In the present disclosure, a wireless device may be a communication modem / circuit / chip.

[0271] Now, the hardware elements of the wireless devices 100 and 200 will be described in more detail. One or more protocol layers may be implemented by (but not limited to) one or more processors 102 and 202. For example, one or more processors 102 and 202 may implement one or more layers (e.g., functional layers such as physical (PHY), medium access control (MAC), radio link control (RLC), packet data convergence protocol (PDCP), RRC, and service data adaptation protocol (SDAP)). One or more processors 102 and 202 may generate one or more protocol data units (PDUs) and / or one or more service data units (SDUs) according to the descriptions, functions, processes, proposals, methods, and / or operational flowcharts disclosed in this document. One or more processors 102 and 202 may generate messages, control information, data, or information according to the descriptions, functions, processes, proposals, methods, and / or operational flowcharts disclosed in this document, and provide these messages, control information, data, or information to one or more transceivers 106 and 206. One or more processors 102 and 202 may generate a signal (e.g., a baseband signal) including a PDU, SDU, message, control information, data, or information according to the description, functions, procedures, proposals, methods, and / or operational flowcharts disclosed in this document, and provide the generated signal to one or more transceivers 106 and 206. One or more processors 102 and 202 may receive a signal (e.g., a baseband signal) from one or more transceivers 106 and 206 and obtain the PDU, SDU, message, control information, data, or information according to the description, functions, procedures, proposals, methods, and / or operational flowcharts disclosed in this document.

[0272] One or more processors 102 and 202 may be referred to as controllers, microcontrollers, microprocessors or microcomputers. One or more processors 102 and 202 may be implemented by hardware, firmware, software or a combination thereof. For example, one or more application specific integrated circuits (ASICs), one or more digital signal processors (DSPs), one or more digital signal processing devices (DSPDs), one or more programmable logic devices (PLDs) or one or more field programmable gate arrays (FPGAs) may be included in one or more processors 102 and 202. The description, function, process, proposal, method and / or operation flow chart disclosed in this document may be implemented using firmware or software, and the firmware or software may be configured to include modules, processes or functions. Firmware or software configured to execute the description, function, process, proposal, method and / or operation flow chart disclosed in this document may be included in one or more processors 102 and 202 or may be stored in one or more memories 104 and 204 and driven by one or more processors 102 and 202. The descriptions, functions, processes, proposals, methods and / or operational flow charts disclosed in this document may be implemented in the form of codes, instructions and / or instruction sets using firmware or software.

[0273] One or more memories 104 and 204 may be connected to one or more processors 102 and 202 and store various types of data, signals, messages, information, programs, codes, instructions and / or commands. One or more memories 104 and 204 may be configured to include read-only memory (ROM), random access memory (RAM), electrically erasable programmable read-only memory (EPROM), flash memory, hard drive, register, cache memory, computer-readable storage medium and / or a combination thereof. One or more memories 104 and 204 may be located inside and / or outside of one or more processors 102 and 202. One or more memories 104 and 204 may be connected to one or more processors 102 and 202 by various technologies such as wired or wireless connections.

[0274] One or more transceivers 106 and 206 can send the user data, control information and / or wireless signal / channel mentioned in the method and / or operation flow chart of this document to one or more other devices. One or more transceivers 106 and 206 can receive the user data, control information and / or wireless signal / channel mentioned in the description, function, process, proposal, method and / or operation flow chart disclosed in this document from one or more other devices. For example, one or more transceivers 106 and 206 can be connected to one or more processors 102 and 202 and send and receive wireless signals. For example, one or more processors 102 and 202 can perform control so that one or more transceivers 106 and 206 can send user data, control information or wireless signal to one or more other devices. One or more processors 102 and 202 can perform control so that one or more transceivers 106 and 206 can receive user data, control information or wireless signal from one or more other devices. One or more transceivers 106 and 206 may be connected to one or more antennas 108 and 208, and one or more transceivers 106 and 206 may be configured to send and receive user data, control information, and / or radio signals / channels mentioned in the description, functions, processes, proposals, methods, and / or operational flow charts disclosed in this document through one or more antennas 108 and 208. In this document, one or more antennas may be multiple physical antennas or multiple logical antennas (e.g., antenna ports). One or more transceivers 106 and 206 may convert the received wireless signals / channels from RF band signals to baseband signals so as to process the received user data, control information, and wireless signals / channels using one or more processors 102 and 202. One or more transceivers 106 and 206 may convert the user data, control information, and wireless signals / channels processed using one or more processors 102 and 202 from baseband signals to RF band signals. To this end, one or more of the transceivers 106 and 206 may include (analog) oscillators and / or filters.

[0275] Example of use of wireless device to which the present disclosure is applied

[0276] Figure 8 Another example of a wireless device applicable to the present disclosure is shown. The wireless device can be based on the use case / service (refer to Figure 6 ) are implemented in various forms.

[0277] Reference Figure 8 , the wireless devices 100 and 200 may correspond to Figure 7The wireless devices 100 and 200 may be configured to include various elements, components, units / parts and / or modules. For example, each of the wireless devices 100 and 200 may include a communication unit 110, a control unit 120, a memory unit 130 and an additional component 140. The communication unit 110 may include a communication circuit 112 and a transceiver 114. For example, the communication circuit 112 may include Figure 7 The one or more processors 102 and 202 and / or the one or more memories 104 and 204 of the present invention. For example, the transceiver 114 may include Figure 7 The control unit 120 is electrically connected to the communication unit 110, the memory 130, and the additional components 140, and provides overall control of the wireless device. For example, the control unit 120 can control the electrical / mechanical operation of the wireless device based on the program / code / instruction / information stored in the memory unit 130. The control unit 120 can send information stored in the memory unit 130 to the outside (e.g., other communication devices) via the communication unit 110 through a wireless / wired interface, or store information received from the outside (e.g., other communication devices) via the communication unit 110 in the memory unit 130 through a wireless / wired interface.

[0278] The additional component 140 may be configured in various ways depending on the type of wireless device. For example, the additional component 140 may include at least one of a power supply unit / battery, an input / output (I / O) unit, a drive unit, and a computing unit. The wireless device may be configured in the form of, but not limited to, a robot ( Figure 6 100a), vehicles ( Figure 6 100b-1 and 100b-2), XR devices ( Figure 6 100c), handheld device ( Figure 6 100d), household appliances ( Figure 6 100e), IoT devices ( Figure 6 100f), digital broadcasting terminal, holographic device, public safety device, MTC device, medical device, fintech device (or financial device), security device, climate / environmental device, AI server / device ( Figure 6 400), BS( Figure 6 200), network nodes, etc. Depending on the use case / service, the wireless device can be mobile or fixed.

[0279] exist Figure 8In the wireless devices 100 and 200, various elements, components, units / parts and / or modules in the wireless devices 100 and 200 may all be connected to each other through a wired interface, or at least a part thereof may be wirelessly connected through the communication unit 110. For example, in each of the wireless devices 100 and 200, the control unit 120 and the communication unit 110 may be wired, and the control unit 120 and the first unit (e.g., 130 and 140) may be wirelessly connected through the communication unit 110. The various elements, components, units / parts and / or modules in the wireless devices 100 and 200 may also include one or more elements. For example, the control unit 120 may be configured using a collection of one or more processors. For example, the control unit 120 may be configured using a collection of a communication control processor, an application processor, an electronic control unit (ECU), a graphics processing unit and a memory control processor. In another example, the memory 130 may be configured using RAM, dynamic RAM (DRAM), ROM, flash memory, volatile memory, non-volatile memory and / or a combination thereof.

[0280] Examples of vehicles or autonomous driving vehicles to which the present disclosure is applied

[0281] Fig. 9 A vehicle or an autonomous vehicle applied to the present disclosure is shown. The vehicle or the autonomous vehicle can be implemented as a mobile robot, a car, a train, a manned / unmanned aerial vehicle (AV), a ship, etc.

[0282] Reference Fig. 9 , the vehicle or autonomous driving vehicle 100 may include an antenna unit 108, a communication unit 110, a control unit 120, a drive unit 140a, a power supply unit 140b, a sensor unit 140c, and an autonomous driving unit 140d. The antenna unit 108 may be configured as a part of the communication unit 110. Blocks 110 / 130 / 140a to 140d correspond to Figure 8 Block 110 / 130 / 140.

[0283] The communication unit 110 may send and receive signals (e.g., data and control signals) to and from external devices such as other vehicles, BSs (e.g., gNBs and roadside units), and servers. The control unit 120 may perform various operations by controlling elements of the vehicle or autonomous driving vehicle 100. The control unit 120 may include an ECU. The drive unit 140a may enable the vehicle or autonomous driving vehicle 100 to travel on a road. The drive unit 140a may include an engine, a motor, a power system, wheels, brakes, a steering device, etc. The power supply unit 140b may supply power to the vehicle or autonomous driving vehicle 100, and include a wired / wireless charging circuit, a battery, etc. The sensor unit 140c may acquire information about the vehicle status, surrounding environment information, user information, etc. The sensor unit 140c may include an inertial measurement unit (IMU) sensor, a collision sensor, a wheel sensor, a speed sensor, a slope sensor, a weight sensor, a heading sensor, a position module, a vehicle forward / reverse sensor, a battery sensor, a fuel sensor, a tire sensor, a steering sensor, a temperature sensor, a humidity sensor, an ultrasonic sensor, a lighting sensor, a pedal position sensor, etc. The autonomous driving unit 140d may implement a technology for maintaining a lane in which the vehicle is traveling, a technology for automatically adjusting a speed (e.g., adaptive cruise control), a technology for autonomously traveling along a determined path, a technology for traveling by automatically setting a route if a destination is set, and the like.

[0284] For example, the communication unit 110 may receive map data, traffic information data, etc. from an external server. The autonomous driving unit 140d may generate an autonomous driving route and a driving plan from the obtained data. The control unit 120 may control the drive unit 140a so that the vehicle or the autonomous driving vehicle 100 may move along the autonomous driving route according to the driving plan (e.g., speed / direction control). During autonomous driving, the communication unit 110 may aperiodically / periodically obtain the latest traffic information data from an external server and obtain surrounding traffic information data from neighboring vehicles. During autonomous driving, the sensor unit 140c may obtain information about the vehicle state and / or surrounding environment information. The autonomous driving unit 140d may update the autonomous driving route and driving plan based on the newly obtained data / information. The communication unit 110 may transmit information about the vehicle position, autonomous driving route, and / or driving plan to an external server. The external server may predict traffic information data using AI technology based on information collected from the vehicle or autonomous driving vehicle, and provide the predicted traffic information data to the vehicle or autonomous driving vehicle.

[0285] Those skilled in the art will appreciate that the present disclosure may be implemented in other specific ways than those described herein without departing from the spirit and basic characteristics of the present disclosure. Therefore, the above-described embodiments are to be interpreted as illustrative in all respects, rather than restrictive. The scope of the present disclosure should be determined by the appended claims and their legal equivalents (rather than the above description), and all changes falling within the meaning and equivalent scope of the appended claims are intended to be included therein.

[0286] Industrial Applicability

[0287] As described above, the present disclosure is applicable to various wireless communication systems.

Claims

1. A method for sending and receiving signals by a user equipment UE in a wireless communication system, the method comprising the following steps: configuring an uplink frequency band including a first frequency band, a second frequency band, and a third frequency band; receiving (i) a first parameter for indicating a state of the transmission Tx chain based on that the state of the Tx chain after uplink switching is not unique and (ii) a second parameter for configuring an associated frequency band for the third frequency band; as well as In an operation state capable of supporting one-port transmission, i.e., first transmission, on each carrier on the first frequency band and the second frequency band, without transmission on the first frequency band and the second frequency band, performing one-port transmission, i.e., second transmission, on a carrier on the third frequency band, wherein the uplink switching is performed based on the second transmission, and Wherein, based on the value of the first parameter indicating one Tx chain and the associated frequency band being configured by the second parameter, the UE considers performing 1-port transmission on each carrier on the third frequency band and the associated frequency band for the uplink switching.

2. The method according to claim 1, wherein: Based on the UE considering performing the 1-port transmission on each carrier on the third frequency band and the associated frequency band, the Tx chain that initially has one Tx chain located in the first frequency band and one Tx chain located in the second frequency band is switched to have one Tx chain located in the third frequency band and one Tx chain located in the associated frequency band.

3. The method according to claim 1, wherein: The switching option between the third frequency band and the associated frequency band is configured to allow simultaneous transmission between the third frequency band and the associated frequency band.

4. The method according to claim 1, wherein: Based on the fact that the value of the first parameter is not configured or the value of the first parameter indicates two Tx chains, the UE considers performing 2-port transmission on the carrier on the third frequency band for the uplink switching.

5. The method according to claim 4, wherein: Based on the UE considering performing the 2-port transmission on the carrier on the third frequency band, the Tx chains initially having one Tx chain located in the first frequency band and one Tx chain located in the second frequency band are switched to be completely located in the third frequency band.

6. The method according to claim 1, wherein: The first parameter and the second parameter are received through radio resource control RRC signaling.

7. The method according to claim 1, wherein: The second parameter also includes information about a second associated frequency band associated with the first frequency band and a third associated frequency band associated with the second frequency band.

8. The method according to claim 1, further comprising the steps of: In an operation state capable of supporting 2-port transmission, i.e., third transmission, on a carrier on the first frequency band, without transmission on the first frequency band, performing 1-port transmission, i.e., fourth transmission, on a carrier on the third frequency band, wherein a second uplink switch is performed based on the fourth transmission, and Wherein, based on that the value of the first parameter indicates one Tx chain and the associated frequency band is configured by the second parameter, the UE considers performing 1-port transmission on each carrier on the third frequency band and the associated frequency band for the second uplink switching.

9. The method according to claim 8, wherein: Based on the UE considering performing the 1-port transmission on the respective carriers on the third frequency band and the associated frequency band, two Tx chains initially located in the first frequency band are switched so that one Tx chain is located in the third frequency band and one Tx chain is located in the associated frequency band.

10. A user equipment UE configured to send and receive signals in a wireless communication system, the UE comprising: at least one transceiver; at least one processor; as well as at least one memory, the at least one memory being operatively connected to the at least one processor and storing instructions that, when executed, cause the at least one processor to perform specific operations, the specific operations comprising: configuring an uplink frequency band including a first frequency band, a second frequency band, and a third frequency band; receiving a first parameter for indicating a state of the transmission Tx chain based on that the state of the Tx chain after uplink switching is not unique and (ii) a second parameter for configuring an associated frequency band for the third frequency band; and In an operation state capable of supporting one-port transmission, i.e., first transmission, on each carrier on the first frequency band and the second frequency band, without transmission on the first frequency band and the second frequency band, performing one-port transmission, i.e., second transmission, on a carrier on the third frequency band, wherein the uplink switching is performed based on the second transmission, and Wherein, based on the value of the first parameter indicating one Tx chain and the associated frequency band being configured by the second parameter, the UE considers performing 1-port transmission on each carrier on the third frequency band and the associated frequency band for the uplink switching.

11. The UE according to claim 10, wherein: Based on the UE considering performing the 1-port transmission on each carrier on the third frequency band and the associated frequency band, the Tx chain that initially has one Tx chain located in the first frequency band and one Tx chain located in the second frequency band is switched to have one Tx chain located in the third frequency band and one Tx chain located in the associated frequency band.

12. The UE according to claim 10, wherein: The switching option between the third frequency band and the associated frequency band is configured to allow simultaneous transmission between the third frequency band and the associated frequency band.

13. The UE according to claim 10, wherein: Based on the fact that the value of the first parameter is not configured or the value of the first parameter indicates two Tx chains, the UE considers performing 2-port transmission on the carrier on the third frequency band for the uplink switching.

14. The UE according to claim 113, wherein: Based on the UE considering performing the 2-port transmission on the carrier on the third frequency band, the Tx chains initially having one Tx chain located in the first frequency band and one Tx chain located in the second frequency band are switched to be completely located in the third frequency band.

15. The UE according to claim 10, wherein: The first parameter and the second parameter are received through radio resource control RRC signaling.

16. The UE according to claim 10, wherein: The second parameters further include information about a second associated frequency band for the first frequency band and a third associated frequency band for the second frequency band.

17. The UE according to claim 10, wherein the specific operation further comprises: In an operation state capable of supporting 2-port transmission, i.e., third transmission, on a carrier on the first frequency band, without transmission on the first frequency band, performing 1-port transmission, i.e., fourth transmission, on a carrier on the third frequency band, wherein a second uplink switch is performed based on the fourth transmission, and Wherein, based on that the value of the first parameter indicates one Tx chain and the associated frequency band is configured by the second parameter, the UE considers performing 1-port transmission on each carrier on the third frequency band and the associated frequency band for the second uplink switching.

18. The UE according to claim 17, wherein: Based on the UE considering performing the 1-port transmission on the respective carriers on the third frequency band and the associated frequency band, two Tx chains initially located in the first frequency band are switched so that one Tx chain is located in the third frequency band and one Tx chain is located in the associated frequency band.

19. A device for a user equipment UE, the device comprising: at least one processor; as well as at least one computer memory operatively connected to the at least one processor and configured to, when executed, cause the at least one processor to perform operations comprising: configuring an uplink frequency band including a first frequency band, a second frequency band, and a third frequency band; receiving a first parameter for indicating a state of the transmission Tx chain based on that the state of the Tx chain after uplink switching is not unique and (ii) a second parameter for configuring an associated frequency band for the third frequency band; and In an operation state capable of supporting one-port transmission, i.e., first transmission, on each carrier on the first frequency band and the second frequency band, without transmission on the first frequency band and the second frequency band, performing one-port transmission, i.e., second transmission, on a carrier on the third frequency band, wherein the uplink switching is performed based on the second transmission, and Wherein, based on the value of the first parameter indicating one Tx chain and the associated frequency band being configured by the second parameter, the UE considers performing 1-port transmission on each carrier on the third frequency band and the associated frequency band for the uplink switching.

20. A computer-readable non-volatile storage medium, the computer-readable non-volatile storage medium comprising at least one computer program, the at least one computer program being configured to cause a user equipment (UE) having at least one processor to perform operations, the operations comprising: configuring an uplink frequency band including a first frequency band, a second frequency band, and a third frequency band; receiving a first parameter for indicating a state of the transmission Tx chain based on that the state of the Tx chain after uplink switching is not unique and (ii) a second parameter for configuring an associated frequency band for the third frequency band; as well as In an operation state capable of supporting one-port transmission, i.e., first transmission, on each carrier on the first frequency band and the second frequency band, without transmission on the first frequency band and the second frequency band, performing one-port transmission, i.e., second transmission, on a carrier on the third frequency band, wherein the uplink switching is performed based on the first transmission and the second transmission, and Wherein, based on the value of the first parameter indicating one Tx chain and the associated frequency band being configured by the second parameter, the UE considers performing 1-port transmission on each carrier on the third frequency band and the associated frequency band for the uplink switching.

21. A method for sending and receiving signals by a base station BS in a wireless communication system, the method comprising the following steps: configuring an uplink frequency band including a first frequency band, a second frequency band and a third frequency band for a user equipment UE; transmitting (i) a first parameter for indicating a state of the transmission Tx chain based on that the state of the transmission Tx chain after uplink switching is not unique and (ii) a second parameter for configuring an associated frequency band for the third frequency band; as well as In an operation state capable of supporting one-port transmission, i.e., first transmission, on each carrier on the first frequency band and the second frequency band, receiving one-port transmission, i.e., second transmission, on the carrier on the third frequency band from the UE without transmission on the first frequency band and the second frequency band, wherein the uplink switching is performed based on the second transmission, and Wherein, based on the value of the first parameter indicating one Tx chain and the associated frequency band being configured by the second parameter, the BS considers performing 1-port transmission on each carrier on the third frequency band and the associated frequency band for the uplink switching.

22. A base station BS configured to send and receive signals in a wireless communication system, the BS comprising: at least one transceiver; at least one processor; as well as at least one memory, the at least one memory being operatively connected to the at least one processor and storing instructions that, when executed, cause the at least one processor to perform specific operations, the specific operations comprising: configuring an uplink frequency band including a first frequency band, a second frequency band and a third frequency band for a user equipment UE; transmitting (i) a first parameter for indicating a state of the transmission Tx chain based on that the state of the transmission Tx chain after uplink switching is not unique and (ii) a second parameter for configuring an associated frequency band for the third frequency band; and In an operation state capable of supporting one-port transmission, i.e., first transmission, on each carrier on the first frequency band and the second frequency band, receiving one-port transmission, i.e., second transmission, on the carrier on the third frequency band from the UE without transmission on the first frequency band and the second frequency band, wherein the uplink switching is performed based on the second transmission, and Wherein, based on the value of the first parameter indicating one Tx chain and the associated frequency band being configured by the second parameter, the BS considers performing 1-port transmission on each carrier on the third frequency band and the associated frequency band for the uplink switching.

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