Method and user equipment for multi-transmit / receive point operation - Patents.com

Abstract

To provide a method and user equipment (UE) for a multi-transmission point (TRP) operation.SOLUTION: A method in a wireless communication system includes the steps of receiving uplink (UL) downlink control information (DCI) including a first transmit precoder matrix indication (TPMI) associated with a first TRP and a second TPMI associated with a second TRP from a base station (BS), transmitting a first physical uplink shared channel (PUSCH) repetition to the first TRP according to the first TPMI, and transmitting a second PUSCH repetition to the second TRP according to the second TPMI.SELECTED DRAWING: Figure 7

Description

[Technical field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims the benefit of and priority to U.S. Provisional Patent Application No. 63 / 023,205, entitled “Mechanisms for Supporting Slot-based PUSCH Repetition under CB based UL Transmission in Multi-TRP,” filed May 11, 2020 (hereinafter the “'205 Provisional Application”), the contents of which are hereby incorporated by reference in their entirety for all purposes.

[0002] [Field] The present disclosure relates generally to wireless communications, and more specifically, to a method and user equipment (UE) for multi-transmission point (TRP) operation. [Background technology]

[0003] With a significant increase in the number of connected devices and a rapid increase in user / network traffic volume, various efforts have been made to improve various aspects of wireless communication systems for next generation wireless communication systems, such as Fifth Generation (5G) New Radio (NR), by improving data speeds, latency, reliability, and mobility. Summary of the Invention [Problem to be solved by the invention]

[0004] The 5G NR system is designed to provide flexibility and configurability to optimize network services and types for a variety of use cases, such as enhanced mobile broadband (eMBB), massive machine type communications (mMTC), and ultra-reliable low latency communications (URLLC).

[0005] However, as the demand for wireless access continues to increase, further improvements in wireless communications are needed for next generation wireless communication systems. [Means for solving the problem]

[0006] The present disclosure is directed to a method and UE for multi-TRP operation.

[0007] According to one aspect of the present disclosure, a method is provided for a multi-transmission / reception point (multi-TRP) based physical uplink shared channel (PUSCH) transmission performed by a user equipment (UE), the method including the steps of receiving, from a base station (BS), a first sounding reference signal (SRS) resource set and a second SRS resource set used for a CodeBook (CB) based PUSCH transmission, receiving from the BS a first radio resource control (RRC) message indicating a mapping pattern for transmitting multiple PUSCH repetitions, receiving from the BS uplink-downlink control information (DCI) including a first DCI field indicating a first transmit precoding matrix indicator (TPMI), a second DCI field indicating a second TPMI, a third DCI field indicating a first SRS resource indicator (SRI), and a fourth DCI field indicating the second SRI, the first TPMI and the second SRS resource set being used for a CodeBook (CB) based PUSCH transmission, receiving from the BS a first radio resource control (RRC) message indicating a mapping pattern for transmitting multiple PUSCH repetitions, the first DCI field indicating a first transmit precoding matrix indicator (TPMI), a second DCI field indicating a second TPMI, a third DCI field indicating a first SRS resource indicator (SRI), and a fourth DCI field indicating a second SRI, the ... first SRS resource indicator (SRI), and the fourth DCI field indicating a second SRI. the TPMI and the second SRI being associated with the first SRS resource set, and the second TPMI and the second SRI being associated with the second SRS resource set; and transmitting, by the UE, the multiple PUSCH repetitions based on the first TPMI, the first SRI, the second TPMI, and the second SRI, wherein the mapping pattern indicates that the first TPMI and the first SRI are mapped to a first PUSCH repetition of the multiple PUSCH repetitions, the second TPMI and the second SRI are mapped to a second PUSCH repetition of the multiple PUSCH repetitions, and the same mapping rule is applied to the remaining PUSCH repetitions of the multiple PUSCH repetitions.

[0008] According to one aspect of the present disclosure, a UE for performing multi-TRP based PUSCH transmission is provided, the UE comprising a transceiver and at least one processor coupled to the transceiver, the processor being configured to control the transceiver to receive from a base station (BS) a first sounding reference signal (SRS) resource set and a second SRS resource set used for a CodeBook (CB) based PUSCH transmission, receive from the BS a first radio resource control (RRC) message indicating a mapping pattern for transmitting multiple PUSCH repetitions, receive from the BS uplink-downlink control information (DCI) including a first DCI field indicating a first transmit precoding matrix indicator (TPMI), a second DCI field indicating a second TPMI, a third DCI field indicating a first SRS resource indicator (SRI), and a fourth DCI field indicating a second SRI, and transmit the multiple PUSCH repetitions based on the first TPMI, the first SRI, the second TPMI, and the second SRI. The first TPMI and the first SRI are associated with the first SRS resource set, the second TPMI and the second SRI are associated with the second SRS resource set, and the mapping pattern is such that the first TPMI and the first SRI are mapped to a first PUSCH repetition of the multiple PUSCH repetitions and the second TPMI and the second SRI are mapped to a second PUSCH repetition of the multiple PUSCH repetitions, and the same mapping rule is applied to the remaining PUSCH repetitions of the multiple PUSCH repetitions.

[0009] According to an aspect of the present disclosure, a BS for receiving a multi-TRP based PUSCH transmission is provided, the BS comprising: a transceiver; and at least one processor coupled to the transceiver, the processor configured to control the transceiver to transmit a first SRS resource set and a second SRS resource set used for a CB based PUSCH transmission, transmit a first RRC message indicating a mapping pattern for transmitting a plurality of PUSCH repetitions, transmit an uplink DCI including a first DCI field indicating a first TPMI, a second DCI field indicating a second TPMI, a third DCI field indicating a first SRI, and a fourth DCI field indicating a second SRI, and receive the plurality of PUSCH repetitions from the UE based on the first TPMI, the first SRI, the second TPMI, and the second SRI. The first TPMI and the first SRI are associated with a first SRS resource set, the second TPMI and the second TPMI are associated with a second SRS resource set, and the mapping pattern indicates that the first TPMI and the first SRI are mapped to a first PUSCH repetition of the multiple PUSCH repetitions, the second TPMI and the second SRI are mapped to the second PUSCH repetition of the multiple PUSCH repetitions, and the same mapping rule is applied to the remaining PUSCH repetitions of the multiple PUSCH repetitions. [Brief description of the drawings]

[0010] Example disclosed embodiments are best understood from the following detailed description when read in conjunction with the accompanying drawings, in which: Various features are not drawn to scale. Dimensions of various features may be arbitrarily increased or decreased for clarity of discussion. [Figure 1] FIG. 1 illustrates a procedure for codebook (CB) based UL transmission according to one embodiment of the present disclosure. [Diagram 2]FIG. 2 is a schematic diagram illustrating multi-TRP operation based on CB-based PUSCH repetition according to one embodiment of the present disclosure. [Diagram 3] FIG. 3 is a schematic diagram illustrating multiple PUSCH repetitions mapped to different TPMIs according to one embodiment of the present disclosure. [Figure 4] FIG. 4 is a schematic diagram illustrating multiple PUSCH repetitions mapped to different TPMIs according to one embodiment of the present disclosure. [Diagram 5] FIG. 5 is a schematic diagram illustrating an SRS resource extension in which the number of SRS resources in an SRS resource set is up to four according to one embodiment of the present disclosure. [Figure 6] FIG. 6 is a schematic diagram illustrating that some PUSCH repetitions are cancelled due to contention with DL slots according to one embodiment of the present disclosure. [Figure 7] FIG. 7 illustrates a flowchart of a method performed by a UE for communicating multiple TRPs, including a first TRP and a second TRP, according to one embodiment of the present disclosure. [Figure 8] FIG. 8 is a block diagram illustrating a node in a wireless communication system according to one embodiment of the present disclosure. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] The following contains specific information related to the embodiments of the present disclosure. The drawings and their accompanying detailed description are directed to the embodiments only. However, the present disclosure is not limited to these embodiments. Other variations and embodiments of the present disclosure will be apparent to those skilled in the art.

[0012] Unless otherwise noted, like or corresponding elements between the drawings may be indicated by like or corresponding reference numerals. Further, the drawings and illustrations in this disclosure are generally not to scale and are not intended to correspond to actual relative dimensions.

[0013] For purposes of consistency and ease of understanding, similar features may be identified by the same numbers in the figures (although in some instances not shown), however, features in different embodiments may differ in other respects and are not intended to be narrowly limited to those shown in the figures.

[0014] The phrases "in one embodiment" or "in some embodiments" may refer to one or more of the same or different embodiments, respectively. The term "coupled" is defined as directly or indirectly connected through intervening parts, and is not necessarily limited to a physical connection. The term "comprising" means "including, but not necessarily limited to," and indicates an open-ended inclusion or membership in a disclosed combination, group, series, or equivalent. The phrase "at least one of A, B, and C" or "at least one of: A, B, and C" means "only A, or only B, or only C, or any combination of A, B, and C."

[0015] The terms "system" and "network" may be used interchangeably. The term "and / or" is only an association relationship to disclose related objects and indicates that a three-way relationship may exist, such as A and / or B may indicate that A exists alone, A and B exist simultaneously, or B exists alone. "A and / or B and / or C" may indicate that at least one of A, B, and C is present. The character " / " generally indicates that related objects are in an "or" relationship.

[0016] For purposes of explanation and not limitation, specific details are set forth such as functional entities, techniques, protocols, standards, etc. to provide an understanding of the disclosed technology. In other instances, detailed descriptions of well-known methods, techniques, systems, architectures, etc. are omitted so as not to obscure the present disclosure with unnecessary detail.

[0017] Those skilled in the art will readily recognize that any disclosed network function or algorithm may be implemented by hardware, software, or a combination of software and hardware. The disclosed functions may correspond to modules, which may be software, hardware, firmware, or any combination thereof.

[0018] A software embodiment may include computer-executable instructions stored on a computer-readable medium, such as a memory or other type of storage device. One or more microprocessors or general-purpose computers having communications processing capabilities can be programmed with the corresponding computer-executable instructions to perform the disclosed network functions or algorithms.

[0019] A microprocessor or general-purpose computer may include the use of an application specific integrated circuit (ASIC), a programmable logic array, and / or one or more digital signal processors (DSPs). Although some of the disclosed embodiments are directed to software installed and executed on computer hardware, alternative embodiments implemented as firmware, or as hardware, or as a combination of hardware and software, are well within the scope of this disclosure. The computer-readable medium may include, but is not limited to, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), flash memory, compact disc read-only memory (CD-ROM), magnetic cassette, magnetic tape, magnetic disk storage, or any other equivalent medium capable of storing computer-readable instructions.

[0020] A wireless communication network architecture, such as a Long Term Evolution (LTE) system, a LTE-Advanced (LTE-A) system, a LTE-Advanced Pro system, or a 5G NR Radio Access Network (RAN), may typically include at least one base station (BS), at least one UE, and one or more optional network elements that provide connectivity within the network. The UE may communicate with a network, such as a Core Network (CN), an Evolved Packet Core (EPC) network, an Evolved Universal Terrestrial RAN (E-UTRAN), a Next Generation Core (NGC), a 5G Core (5GC), or the Internet, via a RAN established by one or more BSs.

[0021] The UE may include, but is not limited to, a mobile station, a mobile terminal, or a device, or a user communication wireless terminal. The UE may be a portable wireless device, including, but not limited to, a mobile phone, a tablet, a wearable device, a sensor, a vehicle, or a personal digital assistant (PDA) with wireless communication capabilities. The UE may be configured to receive and transmit signals over an air interface to one or more cells in the RAN.

[0022] The BS provides communication services according to at least a radio access technology (RAT), such as Worldwide Interoperability for Microwave Access (WiMAX), Global System for Mobile Communications (GSM), often referred to as 2G, Enhanced Data Rates for GSM (EDGE) RAN for GSM Evolution, General Packet Radio Service (GPRS), Universal Mobile Telecommunications System (UMTS), often referred to as 3G based on basic Wideband Code Division Multiple Access (W-CDMA), High Speed ​​Packet Access (HSPA), LTE, LTE-A, 5GC, NR (often referred to as 5G), and / or LTE connected to LTE-A Pro (eLTE), however, the scope of this disclosure is not limited to these protocols.

[0023] The BS may include, but is not limited to, a Node B (NB) in UMTS, an Evolved Node B (eNB) in LTE or LTE-A, a Radio Network Controller (RNC) in UMTS, a BS Controller (BSC) in GSM / GERAN, a Next Generation eNB (ng-eNB) in an Evolved Universal Terrestrial Radio Access (E-UTRA) BS associated with 5GC, a Next Generation Node B (gNB) (or 5G Access Network (5G-AN)) in 5G-RAN, or any other device capable of controlling wireless communication and managing radio resources in a cell. The BS may serve one or more UEs over an air interface.

[0024] A BS may provide radio coverage for a particular geographic area using multiple cells included in the RAN. The BS may support the operation of cells. Each cell may be operable to serve at least one UE within its radio coverage.

[0025] Each cell (often referred to as a serving cell) may provide services for serving one or more UEs within its radio coverage such that each cell schedules downlink (DL) and optionally uplink (UL) resources to at least one UE within its radio coverage for DL ​​and optionally UL packet transmissions. A BS may communicate with one or more UEs in a wireless communication system via multiple cells.

[0026] A cell may allocate sidelink (SL) resources to support proximity services (ProSe), LTE SL services, and / or LTE / NR Veagle-to-Everything (V2X) services. Each cell may have a coverage area that overlaps with other cells.

[0027] In case of Multi-RAT Bidirectional Connectivity (MR-DC), a primary cell of a Master Cell Group (MCG) or a Secondary Cell Group (SCG) may be referred to as a Special Cell (SpCell). A Primary Cell (PCell) may refer to an SpCell of an MCG. A Primary SCG Cell (PSCell) may refer to an SpCell of an SCG. An MCG may refer to a group of serving cells associated with a Master Node (MN) and includes an SpCell and optionally one or more SCells. An SCG may refer to a group of serving cells associated with a Secondary Node (SN), including an SpCell and optionally one or more SCells.

[0028] As disclosed above, the frame structure for NR supports flexible configuration to accommodate various next-generation (e.g., 5G) communication requirements such as eMBB, mMTC, and URLLC, while meeting high reliability, high data rate, and low latency requirements. Orthogonal Frequency Division Multiplexing (OFDM) technology in 3GPP can serve as a baseline for NR waveforms. Scalable OFDM numerology, such as adaptive subcarrier spacing, channel bandwidth, and cyclic prefix (CP), can also be used.

[0029] Two coding schemes are considered for NR, specifically, low-density parity check (LDPC) codes and polar codes. The adaptation of the coding scheme can be set based on the channel conditions and / or the service application.

[0030] At least DL transmission data, guard period, and UL transmission data must be included in one NR frame transmission time interval (TTI). The respective portions of DL transmission data, guard period, and UL transmission data should also be configurable, for example, based on NR network dynamics. SL resources may be provided in NR frames to support ProSe or V2X services.

[0031] In Release 16 (Rel-16) NR, a Physical Downlink Shared Channel (PDSCH) repetition mechanism can be used in multi-TRP scenarios for certain services, such as URLLC. With the introduction of the PDSCH repetition mechanism, the PDSCH can be repeatedly transmitted once or multiple times, and as a result, the reliability of the PDSCH transmission is improved.

[0032] In addition to the above-mentioned PDSCH extensions in multi-TRP, the extension of the transmission of other types of physical channels (e.g., Physical Uplink Shared Channel (PUSCH), Physical Downlink Control Channel (PDCCH), or Physical Uplink Control Channel (PUCCH)) in multi-TRP scenarios still requires further clarification.

[0033] For PUSCH, two types of transmissions are supported in NR: codebook (CB)-based transmission and non-codebook (non-CB)-based transmission. CB-based UL transmission is used in commercial communication systems such as W-CDMA, LTE, and NR. The operation of CB-based UL transmission may depend on network (NW) indications (e.g., transmission parameters including transmission rank indication (TRI), transmission precoder matrix indication (TPMI), sounding reference signal (SRS) resource indication (SRI), modulation coding scheme (MCS), and / or transmit power control (TPC)). TRI and TPMI may be common signal content and may be associated with an SRS resource set including at least one SRS resource used for channel sounding at the NW side. In NR, a UE may be configured with multiple SRS resource sets. At least one of the configured SRS resource sets may be indicated by the NW via the SRI. The value of the aforementioned NW indication may be determined by the network based on the channel condition for the UE. In this disclosure, TPMI may be referred to as Precoder Matrix Indication (PMI). The terms "TPMI" and "PMI" are not currently uniformly named in the industry, and therefore are collectively referred to as "TPMI" in this disclosure.

[0034] FIG. 1 illustrates a procedure for CB-based UL transmission according to one embodiment of the present disclosure. As shown in FIG. 1, in action 102, UE 120 may report a UE capability message to BS 140 (e.g., gNB). In action 104, BS 140 may configure the UE with one or more SRS resource sets (e.g., via RRC signaling). In action 106, UE 120 may transmit the configured SRS resources to BS 140 for UL channel estimation. In action 108, BS 140 may calculate a precoder and rank based on the SRS resources received from UE 120. In action 110, BS 140 may provide one or more transmission parameters (e.g., TRI, TMPI, and / or SRI) to UE 120 via a scheduling DCI (or "UL DCI"). In action 112, UE 120 may perform PUSCH transmission based on the transmission parameters provided in the scheduling DCI.

[0035] According to some embodiments of the present disclosure, PUSCH extension in NR may be achieved by introducing a repetition mechanism into PUSCH transmission to improve transmission reliability, with different PUSCH repetitions targeting different TRPs. When the repetition mechanism is applied, the NW may include some transmission parameters (e.g., TPMI, MCS, and / or TPC) in the scheduling DCI to inform the UE how to perform the PUSCH repetition. In this disclosure, a "PUSCH repetition" may refer to one of one or more repeated PUSCH transmissions performed by the UE.

[0036] For CB-based PUSCH transmission, the UL beam associated with the TPMI and TMPI indicated by the scheduling DCI may be applied to the PUSCH transmission. In a multi-TRP scenario, different TRPs may be located at different geographical locations. Therefore, the transmission parameters for PUSCH transmission to different TRPs may be different due to different channel conditions. Details on how to signal multiple sets of transmission parameters for repeated TRP / PUSCH transmissions to the UE may require clarification.

[0037] On the other hand, in higher frequency bands, such as frequency range 2 (FR2), larger channel attenuation is expected. To compensate for the additional channel loss value in the higher frequency bands, beamforming techniques may be applied. A UE with beamforming capability is usually equipped with multiple antenna panels. As each antenna panel provides spatial coverage potential in different directions, the multiple antenna panels contribute to the aggregate spatial coverage in an isotropic / omnidirectional manner. As a result, selecting an antenna panel applicable to a PUSCH repetition is another issue for PUSCH extension in multi-TRP. On an antenna panel (or simply called a "panel"), one or more antenna elements may be arranged in a specific manner to form an antenna array. Each antenna panel may be used as a basic unit for beamforming. Therefore, beam indication may need to be considered along with panel selection / indication.

[0038] As mentioned above, for CB-based PUSCH transmission, the UE may report its capabilities (eg, support for full coherence, partial coherence, or no coherence between individual antenna ports) to the BS.

[0039] The BS may determine the search range of the precoder according to the capability of the UE to reduce computational complexity. The BS may then configure the SRS resource set to the UE for channel training purposes. According to Release 15 (Rel-15) / Rel-16, the SRS resource set associated with the CB-based PUSCH transmission may include up to two SRS resources, and each of the SRS resources may be associated with a different panel. After the UE transmits the SRS resources in the SRS resource set to the BS, the BS may perform channel evaluation to select an appropriate precoder, rank, and associated SRS resource. The precoder, rank, and SRS resource selected by the BS may then be provided to the UE via DCI to schedule the PUSCH transmission. The SRS resource selection may involve panel selection, since each SRS resource in the SRS resource set may be transmitted via a beam associated with a particular panel. In this sense, the SRI provided in the scheduling DCI may be considered as a panel indication.

[0040] 2 is a schematic diagram illustrating a multi-TRP operation based on CB-based PUSCH repetition according to one embodiment of the present disclosure. As shown in FIG. 2, a UE 202 is in a multi-TRP scenario in which two TRPs 204 and 206 are in communication with the UE 202.

[0041] If the UE 202 supports using different TPMIs for different PUSCH repetitions, the UE 202 may have some capabilities (e.g., fast panel switching) to execute NW commands carried in DCI signaling. For example, the UE 202 may execute PUSCH repetitions #0, #2, and #4 using panel #0 / SRI #0 and TPMI #0, and execute PUSCH repetitions #1, #3, and #5 using panel #1 / SRI #1 and TPMI #1. In such a case, a panel switch may be executed in each time slot (e.g., slot #0, #1, #2, #3, #4, or #5).

[0042] The UE 202 may explicitly or implicitly inform the network whether the UE 202 supports fast panel switching (e.g., via a UE capability message) and / or may inform the network whether the UE 202 supports performing PUSCH repetitions with different TPMI / panel indications for different TRPs. For example, in the case of a UE that supports performing multi-panel transmissions, the network may know that the UE may also support performing PUSCH repetitions with different TPMI / panel indications for different TRPs. Fast panel switching may refer to the process of switching to another antenna panel for reception / transmission in a relatively short period of time (e.g., a slot or a fast period having a length shorter than a slot).

[0043] The UE may select an applicable panel (e.g., a panel that provides a maximum channel gain) to transmit PUSCH (repetitions) to different TRPs. During the training phase, different SRS resources may be transmitted via different UL beams associated with different panels. According to some embodiments of the present disclosure, the size of the SRS resource set may be extended (referred to as "SRS resource extension" in this disclosure). For example, the maximum number of SRS resources in an SRS resource set may be more than one. When SRS resource extension is applied, information required for UL transmission (e.g., PUSCH transmission) may be provided in a UL transmission configuration indication (TCI) field and / or SRI in DCI. For example, such information may include power-related information, beam-related information (e.g., beam indication), precoder (e.g., TPMI), SRS resource index used to derive the required information, and / or panel indication.

[0044] In accordance with some embodiments of the present disclosure, a single DCI (i.e., a single DCI message) may include multiple TPMIs and multiple SRIs / panel indications, where each TPMI may identify a precoder to be applied to the UL transmission, and each SRI (or panel indication) may identify a panel for performing the UL transmission. In one embodiment, the (single) DCI may have a UL DCI format including at least two TPMI fields and at least two SRI fields (or panel indication fields), where each TPMI field may include a TPMI, and each SRI field (or panel indication field) may include an SRI (or panel indication). As mentioned above, the SRI field (or SRI) may be used to implicitly indicate a panel suitable to be used for a PUSCH transmission. In one embodiment, the bit length of the TPMI and / or SRI (or panel indication) may be increased depending on the number of TRPs and / or the number of panels on the UE. For example, the bit length of the TPMI and / or SRI (or panel indication) may depend on the number of active panels on the UE. In one embodiment, a table may be provided that describes the correspondence between the values ​​indicated by the TPMI / SRI / Panel Indication fields and the corresponding precoder / beam / panel.

[0045] If carrying multiple TPMI and SRI (or panel indications) in a single DCI is not supported, the UE may obtain information from RRC signaling regarding whether the TPMI and SRI (or panel indication) associated with each PUSCH repetition remains the same. If the UE obtains information from (dedicated) RRC signaling indicating that the TPMI and SRI (or panel indication) for each PUSCH repetition remains the same, the UE may expect that the DCI format monitoring the PUSCH transmission in the multi-TRP carries only one TPMI and / or one SRI (or panel indication), for example, but not limited to, only one TPMI, SRI (or panel indication) field, or only one UL TCI in the DCI format associated with information on the TPMI, SRI (or panel indication) or providing information on the TPMI, SRI (or panel indication). In one embodiment, the network may inform the UE of the number of DCIs that the UE should receive for a PUSCH repetition (i.e., the number of DCI messages that the UE should receive for a PUSCH repetition) in a multi-TRP operation.

[0046] PUSCH repetitions triggered by the same UL DCI may be mapped to different beams, panels, or redundancy versions (RVs). The rules for mapping RVs, beams, and / or panels to PUSCH repetitions may be pre-determined.

[0047] 3 is a schematic diagram illustrating multiple PUSCH repetitions mapped to different TPMIs according to an embodiment of the present disclosure. As shown in FIG. 3, the mapping relationship between PUSCH repetitions (e.g., PUSCH repetitions #0, #1, #2, #3, #4, and #5) and TPMIs is based on a round robin rule. For example, if UE302 is configured with two TPMIs (e.g., TPMI#0 and TMPI#1), each indicating a (transmit) precoder for PUSCH transmission to a TRP (e.g., TRP304 or TRP306), two RVs (e.g., RV#0 and RV#2), two panel indications (e.g., panel#1 and panel#3), each indicating an (antenna) panel provided on UE302, and six PUSCH repetitions (i.e., the number of repetitions for one PUSCH scheduling is six), then according to the round robin rule, TPMI#0, RV#1 and panel#1 can be mapped to PUSCH repetition#0, PUSCH repetition#2, and PUSCH repetition#4, while TPMI#1, RV#2 and panel#3 can be mapped to PUSCH repetition#1, PUSCH#3, and PUSCH#5. In other words, UE302 may apply TPMI#0, RV#0 and panel #1 to perform PUSCH repetitions #0, #2 and #4, and may apply TPMI#1, RV#2 and panel #3 to perform PUSCH repetitions #0, #2 and #4.

[0048] In one embodiment, the multiple PUSCH repetitions may be divided into one or more groups, and each group may map to a particular TPMI, RV, beam, and / or panel indication. The number of groups may be determined based on the number of parameter sets (e.g., TPMI, RV, and / or panel indication) indicated by the NW, as shown in FIG.

[0049] 4 is a schematic diagram illustrating multiple PUSCH repetitions mapped to different TPMIs according to one embodiment of the present disclosure. As shown in FIG. 4, if a UE 402 is configured with two TPMIs (e.g., TPMI#0 and TMPI#1), each indicating a (transmit) precoder for PUSCH transmission to a TRP (e.g., TRP404 or TRP406), two RVs (e.g., RV#0 and RV#2), two panel indications (e.g., panel#1 and panel#3), each indicating an (antenna) panel equipped on the UE 402, and six PUSCH repetitions (i.e., PUSCH repetitions#0, #1, #2, #3, #4, and #5), the six PUSCH repetitions can be divided into two groups (e.g., a first group including PUSCH repetitions#0, #1, and #2, and a second group including PUSCH repetitions#3, #4, and #5), each of which is mapped to a specific set of parameters. For example, a first group may map to TPMI#0, RV#0, and panel#1, and a second group may map to TPMI#1, RV#2, and panel#3.

[0050] In one embodiment, the UL TCI carried by the DCI format or RRC message may be used to indicate which mapping rule should be applied (e.g., round-robin based mapping as shown in FIG. 3 or group-based mapping as shown in FIG. 4).

[0051] [UE Capability Report] For PUSCH extension in multi-TRP, there may be only one of the panels on the UE to be activated for simultaneous transmission. The UE may need to support panel switching to process instructions from the gNB. For example, the gNB may request the UE to perform PUSCH repetitions in a set of (time) slots with UL resources, and the PUSCH repetitions transmitted in each time slot may be transmitted via different panels of the UE. The panels of the UE may correspond to different TRPs. The set of slots may include multiple time slots that are consecutive in the time domain. As shown in Figures 2, 3 or 4, slots #0 to #5 are considered to be consecutive in the time domain because they are arranged one after the other in the time domain. In another embodiment, the set of slots may include one or more slots that are not consecutive in the time domain.

[0052] To execute the instruction, the UE may switch the panel from one to another in different slots indicated for PUSCH transmission. The panel switching may be the fast panel switching described above, since transmissions in two adjacent slots may be applied with different panels. The UE may inform the gNB via explicit signaling or other implicit methods whether it can support multiple TPMI and SRI (or panel indication) for PUSCH repetition in multiple TRPs.

[0053] In some embodiments, if the UE supports performing PUSCH repetition in a multi-TRP scenario, the UE may inform the gNB of whether it has such UE capability. For example, the UE may inform the gNB that it supports performing PUSCH repetition in a multi-TRP scenario. In another embodiment, the UE may inform the gNB that it supports performing PUSCH repetition in a multi-TRP scenario with fast panel / beam switching.

[0054] In some embodiments, a new information element (IE) field may be added to specific signaling to inform the network whether the UE supports fast panel switching in a multi-TRP scenario. If fast panel switching is supported, such signaling may be supported for non-fallback DCI formats, such as formats 0_1 and / or 0_2.

[0055] In some embodiments, a new IE field may be added in the parameters (eg, MIMO-ParametersPerBand) to indicate whether the UE supports performing PUSCH repetition in a multi-TRP scenario with fast panel switching.

[0056] In one embodiment, an IE may be provided to indicate whether the UE supports applying multiple transmit precoders (e.g., whether the UE supports decoding / parsing DCI formats having one or more TPMI fields, each containing at least one TPMI value). For example, the IE may be a parameter pusch-multiTPMI having an enumerated data type (as defined by Abstract Syntax Notation One (ASN.1)) used to represent one of a list of enumerated values. One example is shown below: pusch-multiTPMI ENUMERATED {supported} OPTIONAL, ENUMERTED represents an enumerated data type, and "supported" is an enumerated value. The value of pusch-multiTPMI may be set to "supported" to indicate that the UE supports applying multiple transmit precoders. In one embodiment, pusch-multiTPMI may further indicate support for performing fast panel switching between multiple indicated precoders obtained from the received TPMI field from a specific frequency range (e.g., frequency range 2 (FR2)).

[0057] In one embodiment, the IE may be used to indicate whether the UE supports decoding / parsing SRS resource information indications included in DCI fields (e.g., SRI field) of the DCI format. Note that the SRI field is just one example of signaling. The IE may provide information on the selected UL beam for the associated PUSCH transmission by providing a reference RS. In one embodiment, the IE may be included in a new field "UL-TCI". The field may coexist with or replace the SRI field. An example of the IE may be represented as follows: pusch-multiSRI ENUMERTED {supported} OPTIONAL, ENUMERTED represents an enumerated data type and "supported" is an enumerated value. The IE pusch-multiSRI may further indicate, for example, that it supports fast panel switching between the indicated beams via the SRI field(s) in a particular frequency band (e.g. FR2).

[0058] In one embodiment, an IE may be provided to indicate support for multiple active UE panels for fast panel switching. Additionally or alternatively, the number of UE panels and / or the number of UE panels that may be simultaneously activated may be reported by the UE. An example IE may be represented as follows: pusch-multiPanelIndication ENUMERTED {supported} OPTIONAL, ENUMERTED represents an enumerated data type and "supported" is an enumerated value. In one embodiment, the IE may further indicate support for multiple transmit precoder indications based on the supported DCI formats and / or may indicate support for multiple UL beam information indications based on the supported DCI formats. The IE may be restricted to a particular frequency band, e.g., FR2.

[0059] In one embodiment, an IE may be provided to indicate support for multiple active UE panels for fast panel switching. Additionally or alternatively, the number of UE panels and / or the number of UE panels that may be simultaneously activated may be reported by the UE. For example, the IE may be expressed as follows: pusch-fastPanelSwitching ENUMERTED {supported} OPTIONAL, ENUMERTED represents an enumerated data type and "supported" is an enumerated value. The IE may further indicate support for multiple transmit precoder indications based on the supported DCI formats and / or may indicate support for multiple UL beam information indications based on the supported DCI formats. The IE may be restricted to a particular frequency band, e.g., FR2.

[0060] In one embodiment, an IE may be provided to indicate support for multiple active UE panels for fast panel switching. Additionally or alternatively, the number of UE panels and / or the number of UE panels that may be simultaneously activated may be reported by the UE. For example, the IE may be expressed as follows: pushch-fastBeamSwitching ENUMERTED {supported} OPTIONAL, ENUMERTED represents an enumerated data type and "supported" is an enumerated value. The IE may further indicate support for multiple transmit precoder indications based on the supported DCI formats and / or may indicate support for multiple UL beam information indications based on the supported DCI formats. The IE may be restricted to a particular frequency band, e.g., FR2.

[0061] In some embodiments, if the UE supports multi-panel transmission, for example, if a Type 1 multi-panel codebook is supported by the UE, which may implicitly indicate that the UE supports fast panel switching, the gNB may transmit a DCI carrying multiple TPMIs and SRIs (or panel indications).

[0062] In some embodiments, if the UE does not report that the relationship between each antenna port is non-coherent, which may implicitly indicate that the UE supports fast panel / beam switching, the gNB may signal a DCI carrying multiple TPMIs.

[0063] In some embodiments, if the UE supports PUSCH repetition (e.g., if the UE reports that pusch-RepetitionMultiSlots is supported) and multi-panel transmission (e.g., if the UE reports that a Type 1 miltiPanel codebook is supported), the UE may implicitly inform the gNB that it may support PUSCH repetition in multi-TRP.

[0064] In some embodiments, the UE may report the number of panels / beams it can use to transmit the PUSCH. After the UE reports its number of available panels / beams, the UE may obtain two or more SRS-CB resource sets (e.g., the use of SRS sets is set in a "codebook") and / or the number of SRS-CB resources (e.g., SRS resources used for CB-based UL transmission) may be greater than two. Moreover, if the network configures two or more SRS-CB resource sets, the UE may transmit each SRS-CB resource set at a different time (e.g., but not limited to, a time slot, a subframe, etc.), e.g., the UE may not simultaneously transmit multiple SRS-CB resource sets in a multi-TRP transmission.

[0065] In some embodiments, if the network indicates that a Type 1 configured grant is used for PUSCH transmission in multi-TRP, the UE may obtain the required information (e.g., TPMIs, SRIs, panel indications, and / or TPC commands for PUSCH transmission) used for PUSCH transmission in a dedicated RRC message.

[0066] [SRS resource extension in SRS resource set for CB-based UL transmission] For CB-based PUSCH extension in multi-TPR, SRS resource extension may be required to increase panel diversity. As previously described, SRS resource extension may refer to increasing the maximum number of SRS resources configured in an SRS-CB resource set (e.g., an SRS resource set used for CB-based UL transmission) to more than two.

[0067] FIG. 5 is a schematic diagram illustrating SRS resource extension where the number of SRS resources in an SRS resource set is up to four, according to one embodiment of the present disclosure. As shown in FIG. 5, an SRS resource set 502 may be configured with up to four SRS resources (e.g., SRS resource #0 510, SRS resource #1 520, SRS resource #2 530, and SRS resource #3 540). Each SRS resource may be mapped to a particular panel / beam. For example, SRS resource #0 510 may be mapped to panel #0 and SRI #0, SRS resource #1 520 may be mapped to panel #1 and SRI #1, SRS resource #2 530 may be mapped to panel #2 and SRI #2, and SRS resource #3 540 may be mapped to panel #3 and SRI #3.

[0068] The UE may transmit SRS resources in the SRS resource set 502 in the UL direction (e.g., if there are four SRS resources configured in the SRS resource set 502, then SRS resource #0 510, SRS resource #1 520, SRS resource #2 530, and SRS resource #3 540). Based on the transmitted SRS resources, the gNB may perform channel estimation to derive appropriate transmission parameters, e.g., a precoder, for a subsequent PUSCH transmission.

[0069] In one embodiment, when there are two TRPs, the network may configure two SRS-CB resource sets to the UE to perform CB-based UL transmission in the multi-TRP. These two SRS-CB resource sets may be transmitted at different times (e.g., different OFDM symbols, time slots, or subframes) configured by the network. Based on the result of the UE capability report (e.g., full coherence, partial coherence, or non-coherence) and the SRS resources included in the two SRS-CB resource sets, the gNB may determine two precoders to support PUSCH repetitions in the multi-TRP. For example, if there are eight PUSCH repetitions and the network configures TPMI=0, the UE may use TPMI(=0) to transmit a specific group of PUSCH repetitions (e.g., including PUSCH repetition #0, PUSCH repetition #2, PUSCH repetition #4, and PUSCH repetition #6). If the TPMI is configured with another value (e.g., 6), the UE may use the TPMI to transmit another group of PUSCH repetitions (e.g., including PUSCH repetition #1, PUSCH repetition #3, PUSCH repetition #5, and PUSCH repetition #7).

[0070] In some embodiments, an SRS-CB resource set (eg, an SRS resource set whose use is set to a "codebook") may include more than two SRS resources (ie, SRS-CB resources).

[0071] In some embodiments, the number of SRS-CB resources may be explicitly indicated in the UL TCI, for example, the UE may obtain the SRS-CB resources (e.g., the number of SRS-CB resources and / or the location of the SRS resources) included in the UL TCI carried in the DCI format.

[0072] In some embodiments, the number of SRS-CB resources may be implicitly indicated. For example, the UE may report the number of panels / beams that can be used for PUSCH transmission. The number of SRS-CB resources may be associated with the number of panels / TX beams. Then, the UE may obtain the information of the SRS resources in the SRS-CB resource set according to the panel / TX beam. For example, if the UE reports that it can use four panels to transmit PUSCH, the UE may expect the number of SRS resources in the SRS-CB resource set to be four or less.

[0073] In some embodiments, the gNB may indicate the same panel / TX beam / TPMI to the UE for transmitting individual PUSCH repetitions.

[0074] In some embodiments, instructing a UE to apply different SRS resources in an SRS resource set may imply that panel switching between associated PUSCH transmissions is required. Panel switching may be subject to switch delays. In other words, there may be a time gap between PUSCH transmissions having at least different panels.

[0075] In some embodiments, the number of SRS resource sets configured for channel sounding for a CB-based UL transmission may be two or more.

[0076] In one embodiment, multiple SRS resource sets may be associated with different panels. In such a case, if multiple SRS resources belonging to different SRS resource sets (associated with different panels) are indicated by the SRI field of the DCI format, it may imply that panel switching between associated PUSCH transmissions is required. In contrast, if one or more SRS resources belonging to the same SRS resource set are indicated by the SRI field of the DCI format, it may imply that panel switching between associated PUSCH transmissions is not required.

[0077] In some embodiments, if the number of SRS resources configured for an SRS resource set (e.g., corresponding to the parameter SRS-ResourceSet) having a corresponding parameter “usage” set in “codebook” exceeds two, the UE may expect that the DCI format for monitoring the PUSCH transmission may satisfy at least one of the following conditions (1) to (3):

[0078] (1) The DCI format includes a TPMI greater than 1 to indicate the precoder used to transmit an individual PUSCH repetition.

[0079] (2) The DCI format includes an SRI greater than 1 to indicate a panel for transmitting a PUSCH repetition. In other words, each PUSCH repetition may be transmitted via a corresponding panel indicated by the SRI.

[0080] (3) The DCI format includes a panel indication greater than 1 to indicate a panel for transmitting the PUSCH repetition. In other words, each PUSCH repetition may be transmitted via a corresponding panel indicated by the panel indication.

[0081] In some embodiments, if the number of SRS resources configured for an SRS resource set (e.g., corresponding to the parameter SRS-ResourceSet) with the corresponding parameter “usage” set in “Codebook” is greater than two, the UE may expect to obtain multiple TPMI, SRI (or Panel Indication) via at least one of the following signaling: The TPMI and SRI (or Panel Indication) fields included in the DCI format; The UL TCI field included in the DCI format; and One or more dedicated RRC messages.

[0082] [Multiple TPMI and SRI (or Panel Indication) Signaling for PUSCH Repetition in Multiple TRPs] As shown in FIG. 2, a UE (e.g., UE 202) may perform PUSCH repetitions (e.g., PUSCH repetitions #0-#5) in a multi-TRP scenario to enhance transmission reliability. Because different TRPs (e.g., TRPs 204 and 206) may be located on different geographic areas, each TRP may correspond to a TPMI and SRI (or panel indication) for the associated PUSCH repetition. In such a case, performing PUSCH repetitions in a multi-TRP scenario may support multiple TPMI / SRI / panel indications.

[0083] In some embodiments, the network may inform the UE of the number of TPMI, SRI (or panel indication) that it needs to acquire for PUSCH transmission within a multi-TRP via dedicated RRC signaling.

[0084] In some embodiments, new fields may be added to the DCI format to carry extra TPMI and SRI (or panel indications). For example, the DCI format may carry two TPMI fields and two SRI fields (or panel indication fields). A pair of TPMI and SRI fields (or panel indication fields) may indicate which TPMI and panel are used to transmit the PUSCH to one TRP, and another pair of TPMI and SRI fields (or panel indication fields) indicates which TPMI and panel are used to transmit the PUSCH to another TRP. From the UE's perspective, the target TRP for each TPMI / SRI pair may not be known. In another embodiment, the target TRP may be known to the UE by associating each TMPI / SRI pair with a different TRP via a specific index, such as CORESETPoolIndex.

[0085] In one embodiment, the bit length of each TPMI and the bit length of each SRI may be defined in the 3GPP Technical Specification (TS) for Rel-16.

[0086] In some embodiments, the DCI format may carry a UL TCI field that provides essential information for UL transmission (e.g., SRI, panel indication, number of PUSCH repetitions, starting position of OFDM symbols for each PUSCH repetition in different slots). Multiple SRIs (or panel indications) may be included in the TCI of the DCI format. For example, the TCI of the DCI format may include two SRI / panel indications. The first SRI (or panel indication) may indicate a beam / panel to be used to transmit the PUSCH repetition to a TRP, and the second SRI (or panel indication) may indicate a beam / panel to be used to transmit the PUSCH repetition to another TRP.

[0087] In some embodiments, in the DCI format, the bit length of the TPMI and SRI (or panel indication) fields may be extended to carry multiple TPMI and SRI (or panel indications). For example, if the gNB indicates two TPMI and two SRI (or panel indications) to the UE, the number of bits of the TPMI and SRI (or panel indication) fields may be twice the number of bits in the TPMI and SRI (or panel indication) fields of Rel-15 / Rel-16. A first portion of the bits may represent the TPMI and SRI (or panel indication) information used to transmit the PUSCH to one TRP, and the remaining portion of the bits may represent the TPMI and SRI (or panel indication) information used to transmit the PUSCH to another TRP. In one embodiment, both the first and second portions include the same number of bits.

[0088] In some embodiments, the UE may obtain the number of PUSCH repetitions via RRC signaling. For slot-based PUSCH repetitions, the UE may obtain the resource allocation for PUSCH transmission (i.e., the starting symbol and the number of consecutive symbols for PUSCH transmission in a slot) via the DCI format. Then, all timeslots used for PUSCH repetitions may follow the same resource allocation.

[0089] The UE may obtain multiple TPMI, SRI (or panel indication) in the DCI format. As shown in Figure 3, the mapping between RV, TPMI, SRI (or panel indication), and PUSCH repetition may be round robin. In some embodiments, if a slot used for PUSCH transmission conflicts with a DL slot scheduled by the network, the PUSCH transmission in that slot may be canceled and the mapping between RV, TPMI, SRI (or panel indication), and PUSCH repetition may not be changed, as shown in Figure 6.

[0090] 6 is a schematic diagram illustrating that some PUSCH repetitions are cancelled due to contention with DL slots according to one embodiment of the present disclosure. As shown in FIG. 6, according to the round robin rule described above, UE 602 should apply TPMI#0 to transmit PUSCH repetitions #0, #2, and #4 to TRP 604 and apply TPMI#1 to transmit PUSCH repetitions #1, #3, and #5 to TRP 606, but since PUSCH repetitions #3 and #4 are allocated to slots #3 and #4, which are DL slots, UE 602 can cancel PUSCH repetitions #3 and #4 allocated to DL slots.

[0091] In some embodiments, the number of repetitions may be indicated by the time domain Resource Allocation (TDRA) field in the UL DCI format. The TDRA table may be extended for such signaling. The extended TDRA table may also include an entry indicating no repetitions for the scheduled PUSCH, i.e., only one PUSCH transmission associated with the scheduling UL DCI.

[0092] In some embodiments, a new TPMI, SRI (or Panel Indication) table may be used for PUSCH transmission in multi-TRP. One example of the table is shown in Table 1.

[0093] [Table 1] JPEG0007649493000002.jpg49169

[0094] According to Table 1, two TPMIs may be provided in each entry for PUSCH transmission. For example, if the UE reports that the relationship between antennas (or antenna ports) is full / partial coherence (CodebookSubset=fullyAndPatrialAndNonCohent), the gNB may indicate index #3 to the UE. The UE may then start to perform PUSCH transmission (e.g., transmitting PUSCH repetitions) by applying TPMI=0 and TPMI=3. In Table 1, the term "layer" represents a transmission channel between the UE and the BS (e.g., gNB). Also, a layer may be considered as a rank of a MIMO channel matrix between the UE and the BS (e.g., gNB).

[0095] In one embodiment, the previously described tables may be related to the following factors (1) and (2): (1) The number of panels / beams used for PUSCH transmission; and (2) The relationship between the UE's antenna ports (e.g., non-coherence, partial coherence, or full coherence), where "full coherence" may mean that all antenna ports may transmit coherently, "partial coherence" may mean that only some of the antenna port pairs may transmit coherently, and "non-coherence" may mean that none of the antenna port pairs may transmit coherently.

[0096] In one embodiment, the table may indicate to the UE to use the same / different TPMI and SRI (or panel indication) for PUSCH transmission.

[0097] In some embodiments, the network may inform the UE via higher layer signaling whether the TPMI and SRI (or panel indication) used for the PUSCH repetitions within the multi-TPR are the same.

[0098] In some embodiments, if the network informs the UE via higher layer signaling that the TPMI and SRI (or panel indication) used for PUSCH repetitions in multiple TRPs are the same, the TPMI and SRI (or panel indication) carried in a single DCI message may be applied for each PUSCH repetition transmitted to different TRPs.

[0099] In some embodiments, the network may directly inform the UE via higher layer signaling that the TPMI and SRI (or panel indication) used for PUSCH repetition in multiple TRPs are different.

[0100] In some embodiments, the UE may monitor two DCI messages in different time slots for PUSCH transmission in multiple TRPs. The UE may obtain multiple indications (e.g., TPMI, SRI (or panel indication), TPC, and / or resource allocation parameters) used for individual PUSCH repetitions.

[0101] In some embodiments, the network may indicate the number of DCI messages that the UE needs to decode to obtain the TPMI and SRI (or panel indication) for a PUSCH repetition.

[0102] In some embodiments, the network may indicate multiple search spaces for the UE to monitor multiple DCI messages. For example, if there are four DCI messages carrying information for UL transmission (e.g., TPMI, SRI, and / or panel indication), the network may configure four search spaces for the UE to monitor the PDCCH. The UE may monitor a DCI format scrambled with a Cell Radio Network Temporary Identifier (C-RNTI) in each of the search spaces configured for UL transmission.

[0103] In some embodiments, the network may indicate multiple RNTIs for the UE to monitor multiple DCI messages in a search space, e.g., a dedicated search space used for multi-TRP transmission. For example, if there are four DCI messages for UL transmission (e.g., TPMI, SRI, and / or panel indication), the network may configure the UE with four RNTIs and one search space for PDCCH monitoring. The UE may then monitor DCI formats scrambled with different Radio Network Temporary Identifiers (RNTIs) in the configured search space for UL transmission.

[0104] In one embodiment, the RNTI used for multiple DCI monitoring may be related to at least one of: (1) the number of TRPs used for UL transmission; and (2) the number of PUSCH repetitions.

[0105] In one embodiment, there is one dedicated RNTI in the dedicated search space used for multiple TRPs. For a given slot, multiple DCI messages may be received to indicate PUSCH repetitions of UL scheduling.

[0106] In one embodiment, DCI messages may correspond to PUSCH repetitions based on a one-to-one correspondence. For example, if there are two DCI messages (e.g., DCI message #1 and DCI message #2) and two PUSCH repetitions (e.g., PUSCH repetition #1 and PUSCH repetition #2), DCI message #1 may include transmission parameters for PUSCH repetition #1, and DCI message #2 may include transmission parameters for PUSCH repetition #2.

[0107] In one embodiment, a single DCI message may correspond to multiple PUSCH repetitions based on a specific (pre)configured rule. For example, a first received DCI message may provide transmission parameters for a first group of PUSCH repetitions (e.g., PUSCH repetitions #0, #2, and #4), and a second received DCI message may include transmission parameters for a second group of PUSCH repetitions (e.g., PUSCH repetitions #1, #3, and #5). From the UE's perspective, the information used to determine the transmission timing of the PUSCH repetitions may be included in a specific DCI message or pre-configured / pre-defined.

[0108] In some embodiments, if the network indicates to the UE that the UE needs to decode only one DCI message, the TPMI and SRI (or panel indication) carried by the DCI message may be applied to each PUSCH repetition for multi-TRP operation. In this situation, each PUSCH repetition transmitted to a corresponding TRP may apply the same TPMI and SRI (or panel indication).

[0109] In some embodiments, when the network indicates to the UE that the UE needs to decode multiple DCI messages, the TPMI and SRI (or panel indication) carried by each of the DCI messages may be applied to transmit at least one corresponding PUSCH repetition to the corresponding TRP. For example, the network may decode two DCI messages to obtain the TPMI and SRI (or panel indication) and indicate to the UE that the number of PUSCH repetitions is 7 and the number of TRPs is 2. In this situation, the TPMI and SRI (or panel indication) included in (or carried by) one of the two DCI messages may be applied to transmit a pre-determined group of PUSCH repetitions (e.g., groups of PUSCH repetitions #0, #2, #4, and #6) to one of the two TRPs, while the TPMI and SRI (or panel indication) included in (or carried by) the other group of the two DCI messages may be applied to transmit the other group of the two TRPs (e.g., groups of PUSCH repetitions #1, #3, and #5) to the other of the two TRPs.

[0110] In some embodiments, when a DCI format can carry only one TPMI and / or only one SRI (or panel indication) for PUSCH transmission for multi-TRP operation, additional TPMI, SRI (or panel indication) may be obtained by the UE from the DCI format via one of the following approaches (1) and (2).

[0111] (1) Deriving additional TPMI and / or SRI (or panel indication) via at least one delta value provided by the network. For example, the network may provide a set of delta values ​​(e.g.,

[0112]

number

[0113] ,

[0114]

number

[0115] If the UE obtains TPMI "X" and SRI (or panel indication) "Y" included in the DCI format, the UE can further derive another set of TPMI and SRI (or panel indication) not included in the DCI format according to a set of delta values ​​from the network. For example, other TPMIs can be set to the corresponding TPMI delta values

[0116]

number

[0117] to a value X (e.g.,

[0118]

number

[0119] ) and other SRIs (or Panel Indications) can be derived by adding the delta value of the corresponding SRI / Panel Indication.

[0120]

number

[0121] to the value Y.

[0122] (2) Derive additional TPMI and / or SRI (or panel indication) according to at least one predefined formula. If the UE obtains a TPMI "X" and an SRI (or panel indication) "Y" included in the DCI format, the UE may further derive another TPMI, X', and another SRI (or panel indication), Y', not included in the DCI format according to the following formula:

[0123]

number

[0124] Or,

[0125]

number

[0126] [Redundancy Version (RV), Beam and Panel Scheduling for each PUSCH repetition] Each PUSCH repetition triggered by the same UL DCI may be associated with a different beam, panel, or RV. In one embodiment, round robin scheduling may be used as the mapping rule. For example, there may be two TPMIs (e.g., TPMI#0 and TMPI#1) representing two transmit precoders applied for PUSCH transmission, two RVs (e.g., RV#0 and RV#2), two panel indications (e.g., panel#1 and panel#3 representing two physical panels equipped in the UE), and seven PUSCH repetitions (i.e., the number of (PUSCH) repetitions for one PUSCH scheduling is seven). According to the round robin rule, TPMI#0, RV#0, and panel#1 may be mapped to PUSCH repetition#0, PUSCH repetition#2, PUSCH repetition#4, and PUSCH repetition#6, and TPMI#1, RV#2, and panel#3 may be mapped to PUSCH repetition#1, PUSCH repetition#3, and PUSCH repetition#5. The PUSCH repetitions may be divided into several groups, with each mapping to a specific RV / beam / panel. The number of PUSCH repetitions in a group may depend on the number of TPMI / RV / panels. For example, seven PUSCH repetitions may be divided into two groups: TPMI-PUSCH repetition mapping, RV-PUSCH repetition mapping, and panel-PUSCH repetition mapping, where TPMI#0, RV#0, and panel#1 may map to PUSCH repetition#0, PUSCH repetition#1, PUSCH repetition#2, and PUSCH repetition#3, and TPMI#1, RV#2, and panel#3 may map to PUSCH repetition#4, PUSCH repetition#5, and PUSCH repetition#6. In one embodiment, the UL TCI included in the DCI format or RRC message may indicate the mapping rule used for PUSCH transmission, e.g., round robin.

[0127] FIG. 7 illustrates a flow chart for a method 700 performed by a UE to communicate a plurality of TRPs, including a first TRP and a second TRP, according to one embodiment of the present disclosure. Although actions 702, 704, and 706 are illustrated as separate actions depicted as independent blocks in FIG. 7, these separately illustrated actions should not necessarily be construed as order dependent. The order in which the actions are performed in FIG. 7 is not intended to be construed as limiting, and any number of the disclosed blocks may be combined in any order to implement the method, or alternative methods. For example, the order of performing actions 704 and 706 may be reversed. Furthermore, each of actions 702, 704, and 706 may be performed independently of the other actions, and may be omitted in some embodiments of the present disclosure.

[0128] In action 702, the UE may receive a UL DCI from a BS. The UL DCI includes a first TPMI associated with a first TRP and a second TPMI associated with a second TRP. The first TRP and the second TRP may be located in different geographic areas and may be combined with the same BS to extend radio coverage of the BS. In action 704, the UE may transmit a first PUSCH repetition to the first TRP according to the first TPMI. In action 706, the UE may transmit a second PUSCH repetition to the second TRP according to the second TPMI.

[0129] In comparison to the "multiple UL DCI messages" described above, the UL DCI described in the method 700 may refer to "one UL DCI message" or "one DCI message." Furthermore, each PUSCH repetition may refer to a repeated PUSCH transmission performed in a PUSCH repetition process in which a PUSCH transmission is repeated by the UE at a set of predefined time positions.

[0130] In some embodiments, the first TPMI and the second TPMI may apply the same number of layers for transmission.

[0131] In some embodiments, the UE may further receive an RRC message from the BS configuring a first SRS resource set and a second SRS resource set, where the first SRS resource set may be associated with the first TRP and the second SRS resource set may be associated with the second TRP. The UE may transmit the first SRS resource set and the second SRS resource set to the first TRP and the second TRP based on the RRC message.

[0132] In some embodiments, the UL DCI may further include a first SRI corresponding to the first SRS resource set and a second SRI corresponding to the second SRS resource set, where each of the first SRS resource set and the second SRS resource set may include up to two SRS resources.

[0133] As mentioned above, the UL DCI may include multiple sets of transmission parameters each associated with one of the multiple TRPs communicating with the UE, and each set of transmission parameters may include a TPMI and / or an SRI (or panel indication). According to the method 700, the correspondence between the multiple sets of transmission parameters and the TRP is notified to the UE via the UL DCI message, so that the UE knows which set of transmission parameters should be used / applied to transmit the corresponding PUSCH repetition to a particular TRP. Since the method 700 modifies the UL DCI from the BS to carry multiple sets of transmission parameters for communicating with multiple TRPs, the signaling overhead for multi-TRP operation is reduced. Thus, the method 700, as well as various other embodiments described in the present disclosure, are more flexible than legacy communication systems and better fit the requirements of multi-TRP operation.

[0134] In some embodiments, the UE may further send a capability message to the BS. The capability message may indicate whether the UE supports multi-TRP-based transmission and / or whether the UE supports fast panel switching for multi-TRP-based transmission. If the UE supports multi-TRP-based transmission, it may mean that the UE can perform scheduled transmission by communicating with multiple TRPs.

[0135] The following may be used to further disclose terms, examples, embodiments, embodiments, actions, and / or behavior.

[0136] Antenna Panel: A conceptual term for the implementation of an antenna in a UE. A panel can be assumed to be an operational unit for controlling transmit spatial filters (beams). A panel typically consists of multiple antenna elements. In one embodiment, a beam can be formed by the panel, and to form two beams simultaneously, two panels are required. Such simultaneous beamforming from multiple panels depends on the UE capabilities. A similar definition for a "panel" may be possible by applying spatial receive filtering properties.

[0137] Beam: The term "beam" here can be replaced by spatial filter. For example, when a UE reports a preferred gNB transmission beam, the UE is essentially selecting the spatial filter to be used by the gNB. The term "beam information" is used to provide information about which beam / spatial filter is being used / selected. In one embodiment, individual reference signals are transmitted by applying individual beams (spatial filters). Thus, the term beam or beam information can be represented by a reference signal resource index.

[0138] [DCI]: DCI means downlink control information, and there are various DCI formats used in LTE in the PDCCH. The DCI format is simply a predefined format in which the downlink control information is packed / formed into the PDCCH and transmitted.

[0139] TCI State: The TCI state includes parameters for configuring the QCL relationship between one or two DL reference signals and a target reference signal set. For example, the target reference signal set may be a DM-RS port of a PDSCH or a PDCCH.

[0140] HARQ: The function ensures delivery between peer entities at Layer 1 (i.e., the physical layer). A single HARQ process supports one Transport Block (TB) when the physical layer is not configured for downlink / uplink spatial multiplexing, and supports one or multiple TBs when the physical layer is configured for downlink / uplink spatial multiplexing. There is one HARQ entity per serving cell. Each HARQ entity supports (several) parallel DL and UL HARQ processes.

[0141] Figure 8 is a block diagram illustrating a node 800 for wireless communication according to one embodiment of the present disclosure. As shown in Figure 8, the node 800 may include a transceiver 820, a processor 828, a memory 834, one or more presentation components 838, and at least one antenna 836. The node 800 may also include a radio frequency (RF) spectrum band module, a BS communication module, a network communication module, a system communication management module, input / output (I / O) ports, I / O components, and a power source (not shown in Figure 8).

[0142] Each of the components may communicate directly or indirectly with each other via one or more buses 840. The node 800 may be a UE or a BS that performs the various functions disclosed with reference to Figures 1-7.

[0143] The transceiver 820 has a transmitter 822 (e.g., transmit / transmit circuitry) and a receiver 824 (e.g., receive / receive circuitry) and may be configured to transmit and / or receive time and / or frequency resource partitioning information. The transceiver 820 may be configured to transmit in different types of subframes and slots, including, but not limited to, enabled, disabled, and flexibly enabled subframe and slot formats. The transceiver 820 may be configured to receive data channels and control channels.

[0144] Node 800 may include a variety of computer-readable media. Computer-readable media may be any available media that can be accessed by node 800, including volatile (and / or non-volatile memory) media and removable (and / or non-removable) media.

[0145] Computer-readable media may include computer storage media and communication media. Computer storage media may include both volatile (and / or nonvolatile) and removable (and / or non-removable) media implemented in any method or technology for storage of information such as computer-readable instructions, data structures, program modules, or data.

[0146] Computer storage media may include RAM, ROM, EPROM, EEPROM, flash memory (or other memory technology), CD-ROM, digital versatile disk (DVD) (or other optical disk storage), magnetic cassette, magnetic tape, magnetic disk storage (or other magnetic storage device), etc. Computer storage media does not have to include propagated data signals. Communication media typically embodied computer readable instructions, data structures, program modules or other data in a modulated data signal such as a carrier wave or other transport mechanism and includes any information delivery media.

[0147] The term "modulated data signal" may mean a signal that has one or more of its characteristics set or changed in such a manner as to encode information in the signal. Communication media may include wired media such as a wired network or direct-wired connection, and wireless media such as acoustic, RF, infrared and other wireless media. Combinations of any of the above should also be included within the scope of computer-readable media.

[0148] The memory 834 may include computer storage media in the form of volatile and / or non-volatile memory. The memory 834 may be removable, non-removable, or a combination thereof. Exemplary memories may include solid-state memory, hard drives, optical disk drives, and the like. As shown in FIG. 8, the memory 834 may store computer readable and / or computer executable programs 832 (e.g., software code) that, when executed, are configured to cause the processor 828 to perform various functions disclosed herein, for example, with respect to FIGS. 1-7. Alternatively, the programs 832 may not be directly executable by the processor 828, but may be configured (e.g., when compiled and executed) to cause the node 800 to perform various functions disclosed herein.

[0149] The processor 828 (e.g., having processing circuitry) may include intelligent hardware devices, such as a central processing unit (CPU), a microcontroller, an ASIC, etc. The processor 828 may include memory. The processor 828 may process data 830 and programs 832 received from memory 834, as well as information transmitted and received via the transceiver 820, the baseband communication module, and / or the network communication module. The processor 828 may also process information for transmission to the transceiver 820 for transmission to the network communication module via the antenna 836 for transmission to the CN.

[0150] One or more presentation components 838 can present a data indication to a person or another device. Examples of presentation components 838 can include a display device, a speaker, a printing component, a vibrating component, and the like.

[0151] According to one aspect of the present disclosure, a method is provided that is performed by a UE to communicate with a plurality of TRPs, including a first TRP and a second TRP, including receiving uplink (UL) downlink control information (DCI) from a base station (BS), the DCI including a first transmit precoder matrix indication (TPMI) associated with the first TRP and a second TPMI associated with the second TRP, transmitting a first physical uplink shared channel (PUSCH) repetition to the first TRP according to the first TPMI, and transmitting a second PUSCH repetition to the second TRP according to the second TPMI.

[0152] According to one aspect of the present disclosure, a UE for communicating with a plurality of TRPs including a first TRP and a second TRP is provided. The UE includes at least one processor, a receiver coupled to the at least one processor, and a transmitter coupled to the at least one processor. The receiver is configured to receive a UL DCI from a BS, the UL DCI including a first TPMI associated with the first TRP and a second TPMI associated with the second TRP. The transmitter is configured to transmit a first PUSCH repetition to the first TRP according to the first TPMI and transmit a second PUSCH repetition to the second TRP according to the second TPMI.

[0153] In view of the present disclosure, it is apparent that various techniques may be used to implement the disclosed concepts without departing from the scope of those concepts. Moreover, while the concepts have been disclosed with specific reference to certain embodiments, those skilled in the art will recognize that changes may be made in form and detail without departing from the scope of those concepts. The disclosed embodiments are therefore considered in all respects to be illustrative and not restrictive. It should also be understood that the present disclosure is not limited to the particular embodiments disclosed. Moreover, many rearrangements, modifications, and substitutions are possible without departing from the scope of the present disclosure.

Claims

1. 1. A method performed by a user equipment (UE) for multi-transmission / reception point (multi-TRP) based physical uplink shared channel (PUSCH) transmission, comprising: receiving, from a BS, a first sounding reference signal (SRS) resource set and a second SRS resource set used for a CodeBook (CB)-based PUSCH transmission; receiving a first radio resource control (RRC) message from the BS indicating a mapping pattern for transmitting multiple PUSCH repetitions; receiving uplink-downlink control information (DCI) from the BS, the DCI including a first DCI field indicating a first transmit precoding matrix indicator (TPMI), a second DCI field indicating a second TPMI, a third DCI field indicating a first SRS resource indicator (SRI), and a fourth DCI field indicating a second SRI, the first TPMI and the first SRI being associated with the first SRS resource set, and the second TPMI and the second SRI being associated with the second SRS resource set; transmitting, by the UE, the multiple PUSCH repetitions based on the first TPMI, the first SRI, the second TPMI, and the second SRI, wherein the mapping pattern indicates that the first TPMI and the first SRI are mapped to a first PUSCH repetition of the multiple PUSCH repetitions, the second TPMI and the second SRI are mapped to a second PUSCH repetition of the multiple PUSCH repetitions, and a same mapping rule is applied to remaining PUSCH repetitions of the multiple PUSCH repetitions.

2. The method of claim 1 , wherein the mapping pattern determines a mapping relationship between the first TPMI, the second TPMI, and the multiple PUSCH repetitions.

3. 2. The method of claim 1, wherein if the multiple PUSCH repetitions are configured grant type 1 PUSCH transmissions, the first TPMI, the second TPMI, the first SRI, and the second SRI are obtained via RRC signaling.

4. The method of claim 1 , wherein the second TPMI applies the same number of layers as indicated by the first TPMI.

5. A UE for performing multi-TRP based PUSCH transmission, comprising: Transceivers, and At least one processor coupled to the transceiver, the processor configuring the transceiver to: Receive, from a BS, a first sounding reference signal (SRS) resource set and a second SRS resource set used for a CodeBook (CB)-based PUSCH transmission; receiving a first radio resource control (RRC) message from the BS indicating a mapping pattern for transmitting multiple PUSCH repetitions; receiving uplink-downlink control information (DCI) from the BS, the uplink-downlink control information (DCI) including a first DCI field indicating a first transmit precoding matrix indicator (TPMI), a second DCI field indicating a second TPMI, a third DCI field indicating a first SRS resource indicator (SRI), and a fourth DCI field indicating a second SRI; and a processor configured to control transmitting the plurality of PUSCH repetitions based on the first TPMI, the first SRI, the second TPMI, and the second SRI; the first TPMI and the first SRI are associated with the first SRS resource set, and the second TPMI and the second SRI are associated with the second SRS resource set; The mapping pattern is such that the first TPMI and the first SRI are mapped to a first PUSCH repetition of the multiple PUSCH repetitions, the second TPMI and the second SRI are mapped to a second PUSCH repetition of the multiple PUSCH repetitions, and the same mapping rule is applied to the remaining PUSCH repetitions of the multiple PUSCH repetitions of the UE.

6. The UE of claim 5 , wherein the mapping pattern determines a mapping relationship between the first TPMI, the second TPMI, and the multiple PUSCH repetitions.

7. The UE of claim 5 , wherein if the multiple PUSCH repetitions are configured grant type 1 PUSCH transmissions, the first TPMI, the second TPMI, the first SRI, and the second SRI are obtained via RRC signaling.

8. The UE of claim 5 , wherein the second TPMI applies the same number of layers as indicated by the first TPMI.

9. A base station (BS) performing multi-TRP based PUSCH transmission, the BS comprising: Transceivers, and At least one processor coupled to the transceiver, the processor configuring the transceiver to: Transmitting a first SRS resource set and a second SRS resource set used for CB-based PUSCH transmission; Transmitting a first RRC message indicating a mapping pattern for transmitting multiple PUSCH repetitions; transmitting an uplink DCI including a first DCI field indicating a first TPMI, a second DCI field indicating a second TPMI, a third DCI field indicating a first SRI, and a fourth DCI field indicating a second SRI; a processor configured to control receiving, from a user equipment (UE), the plurality of PUSCH repetitions based on the first TPMI, the first SRI, the second TPMI, and the second SRI; the first TPMI and the first SRI are associated with a first SRS resource set, and the second TPMI and the second TPMI are associated with a second SRS resource set; a BS, the mapping pattern indicating that the first TPMI and the first SRI are mapped to a first PUSCH repetition of the plurality of PUSCH repetitions, the second TPMI and the second SRI are mapped to a second PUSCH repetition of the plurality of PUSCH repetitions, and the same mapping rule is applied to the remaining PUSCH repetitions of the plurality of PUSCH repetitions.

10. The BS of claim 9 , wherein the mapping pattern determines a mapping relationship between the first TPMI, the second TPMI, and the multiple PUSCH repetitions.

11. The BS of claim 9 , wherein if the multiple PUSCH repetitions are configured grant type 1 PUSCH transmissions, the first TPMI, the second TPMI, the first SRI, and the second SRI are obtained via RRC signaling.

12. The BS of claim 9 , wherein the second TPMI applies the same number of layers as indicated by the first TPMI.

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