Terminal, wireless communication method, base station and system

Abstract

A terminal according to an aspect of the present disclosure comprises: a reception unit that receives downlink control information for scheduling an uplink shared channel involving a plurality of repetitions using the same frequency resource and the same temporal resource; and a control unit that determines a combination of a plurality of demodulation reference signal (DMRS) ports, on the basis of the downlink control information.

Description

Terminal, wireless communication method and base station

[0001] The present disclosure relates to a terminal, a wireless communication method, and a base station in a next-generation mobile communication system.

[0002] Long Term Evolution (LTE) has been specified for the Universal Mobile Telecommunications System (UMTS) network with the aim of achieving higher data rates and lower latency (Non-Patent Document 1). Also, LTE-Advanced (3GPP Rel. 10-14) has been specified with the aim of achieving higher capacity and more advanced features than LTE (Third Generation Partnership Project (3GPP (registered trademark)) Release (Rel.) 8, 9).

[0003] Successor systems to LTE (e.g., 5th generation mobile communication system (5G), 5G+ (plus), 6th generation mobile communication system (6G), New Radio (NR), 3GPP Rel. 15 or later, etc.) are also being considered.

[0004] 3GPP TS 36.300 V8.12.0 “Evolved Universal Terrestrial Radio Access (E-UTRA) and Evolved Universal Terrestrial Radio Access Network (E-UTRAN); Overall description; Stage 2 (Release 8)”, April 2010

[0005] For future wireless communication systems (e.g., Rel. 18 NR), it is being considered to increase the number of demodulation reference signal (DMRS) ports for the uplink shared channel (Physical Uplink Shared Channel (PUSCH)). Such new DMRS ports, which are different from existing DMRS ports (also called Rel. 15 DMRS ports), are also called Rel. 18 DMRS ports.

[0006] However, it is not clear how to indicate the new DMRS port, which may result in a decrease in throughput.

[0007] Therefore, one of the objectives of the present disclosure is to provide a terminal, a wireless communication method, and a base station that can appropriately use a new DMRS port.

[0008] A terminal according to one aspect of the present disclosure includes a receiver that receives downlink control information that schedules an uplink shared channel with multiple repetitions using the same frequency resource and the same time resource, and a controller that determines a combination of multiple demodulation reference signal (DMRS) ports based on the downlink control information.

[0009] According to one aspect of the present disclosure, the new DMRS port can be appropriately utilized.

[0010] Figure 1 shows an example of the association between codebook subsets and TPMI indexes. Figure 2 shows an example of a table of precoding matrices W for two-layer (rank-2) transmission using four antenna ports when transform precoding is disabled in Rel. 16 NR. Figures 3A-3C show examples of methods 1 to 3 for simultaneous UL transmission using multiple panels. Figures 4A-4C show examples of PUSCH transmission methods. Figures 5A-5C show other examples of PUSCH transmission methods. Figure 6 shows an example of an existing DMRS port table for DMRS configuration type 1. Figure 7 shows an example of an existing DMRS port table for DMRS configuration type 2. Figure 8 shows an example of an antenna port indication table for PDSCH. Figures 9A to 9D show examples of FD-OCC with a length of 4 / 6. Figure 10 shows an example of FD-OCC with a length of 4. Figure 11 shows a first example of a new DMRS port table for DMRS configuration type 1. FIG. 12 shows a second example of a new DMRS port table for DMRS configuration type 1. FIG. 13 shows a third example of a new DMRS port table for DMRS configuration type 1. FIG. 14 shows an example of a new DMRS port table for DMRS configuration type 2. FIGS. 15A and 15B show examples of multiple antenna port indication tables for multiple antenna coherence assumptions. FIG. 16 shows an example of an antenna port indication table common to multiple antenna coherence assumptions. FIGS. 17A-17D show examples of tables of referenced antenna ports when the transform precoder is disabled, the DMRS type is 1, and the maximum DMRS length is 2. FIGS. 18A and 18B show examples of tables of referenced antenna ports when the transform precoder is disabled, the DMRS type is 2, and the maximum DMRS length is 1. FIGS. 19A-19D show examples of tables of referenced antenna ports when the transform precoder is disabled, the DMRS type is 2, and the maximum DMRS length is 2. Figure 20 is a diagram showing an example of an antenna port instruction table to be referenced when the transform precoder is disabled, the DMRS type is 1, the maximum DMRS length is 1, and the rank is 5 according to embodiment #2-1.Fig. 21 is a diagram showing an example of an antenna port instruction table to be referenced when a transform precoder is disabled, a DMRS type = 1, a maximum DMRS length = 1, and a rank = 6 according to embodiment #2-1. Fig. 22 is a diagram showing an example of an antenna port instruction table to be referenced when a transform precoder is disabled, a DMRS type = 1, a maximum DMRS length = 1, and a rank = 7 according to embodiment #2-1. Fig. 23 is a diagram showing an example of an antenna port instruction table to be referenced when a transform precoder is disabled, a DMRS type = 1, a maximum DMRS length = 1, and a rank = 8 according to embodiment #2-1. Fig. 24 is a diagram showing an example of an antenna port instruction table to be referenced when a transform precoder is disabled, a DMRS type = 2, a maximum DMRS length = 1, and a rank = 5 according to embodiment #2-1. Fig. 25 is a diagram showing an example of an antenna port instruction table to be referenced when a transform precoder is disabled, a DMRS type = 2, a maximum DMRS length = 1, and a rank = 6 according to embodiment #2-1. Fig. 26 is a diagram showing an example of an antenna port instruction table to be referenced when a transform precoder is disabled, a DMRS type = 2, a maximum DMRS length = 1, and a rank = 7 according to embodiment #2-1. Fig. 27 is a diagram showing an example of an antenna port instruction table to be referenced when a transform precoder is disabled, a DMRS type = 2, a maximum DMRS length = 1, and a rank = 8 according to embodiment #2-1. Fig. 28 is a diagram showing an example of an antenna port instruction table to be referenced when a transform precoder is disabled, a DMRS type = 1, a maximum DMRS length = 2, and a rank = 5. Fig. 29 is a diagram showing an example of an antenna port instruction table to be referenced when a transform precoder is disabled, a DMRS type = 1, a maximum DMRS length = 2, and a rank = 6. FIG. 30 is a diagram showing an example of an antenna port indication table to be referenced when the transform precoder is disabled, the DMRS type is 1, the maximum DMRS length is 2, and the rank is 7.Fig. 31 is a diagram showing an example of an antenna port instruction table to be referenced when the transform precoder is disabled, the DMRS type is 1, the maximum DMRS length is 2, and the rank is 8. Figs. 32A and 32B are diagrams showing an example of switching of the antenna port instruction table according to embodiment #4. Fig. 33 shows an example of the size of the antenna port field in Rel. 17. Figs. 34A and 34B show an example of the antenna port field in option 5-2 according to embodiment #5. Fig. 35 is a diagram showing an example of a schematic configuration of a wireless communication system according to an embodiment. Fig. 36 is a diagram showing an example of the configuration of a base station according to an embodiment. Fig. 37 is a diagram showing an example of the configuration of a user terminal according to an embodiment. Fig. 38 is a diagram showing an example of the hardware configuration of a base station and a user terminal according to an embodiment. Fig. 39 is a diagram showing an example of a vehicle according to an embodiment.

[0011] (Control of Transmission of SRS and PUSCH) In Rel. 15 NR, a terminal (user terminal, User Equipment (UE)) may receive information (SRS configuration information, for example, parameters in the RRC control element "SRS-Config") used for transmitting a measurement reference signal (for example, a sounding reference signal (SRS)).

[0012] Specifically, the UE may receive at least one of information regarding one or more SRS resource sets (SRS resource set information, e.g., the RRC control element "SRS-ResourceSet") and information regarding one or more SRS resources (SRS resource information, e.g., the RRC control element "SRS-Resource").

[0013] An SRS resource set may be associated with (or group together) a predetermined number of SRS resources, each of which may be identified by an SRS Resource Indicator (SRI) or SRS Resource Identifier (ID).

[0014] The SRS resource set information may include an SRS resource set ID (SRS-ResourceSetId), a list of SRS resource IDs (SRS-ResourceId) used in the resource set, an SRS resource type, and information on SRS usage.

[0015] Here, the SRS resource type may indicate any one of periodic SRS (P-SRS), semi-persistent SRS (SP-SRS), and aperiodic CSI (Aperiodic SRS (A-SRS)). Note that the UE may transmit the P-SRS and SP-SRS periodically (or periodically after activation), and transmit the A-SRS based on an SRS request in the downlink control information (Downlink Control Information (DCI)).

[0016] Furthermore, the use ("usage" of the RRC parameter, "SRS-SetUse" of the L1 (Layer-1) parameter) may be, for example, beam management, codebook (CB), non-codebook (NCB), antenna switching, etc. The SRS for codebook or non-codebook use may be used to determine a precoder for codebook-based or non-codebook-based uplink shared channel (Physical Uplink Shared Channel (PUSCH)) transmission based on the SRI.

[0017] For example, in the case of codebook-based transmission, the UE may determine a precoder (precoding matrix) for PUSCH transmission based on the SRI, transmission rank (which may simply be referred to as rank), and a Transmitted Precoding Matrix Indicator (TPMI). In the case of non-codebook-based transmission, the UE may determine a precoder for PUSCH transmission based on the SRI.

[0018] The SRS resource information may include an SRS resource ID (SRS-ResourceId), the number of SRS ports, the SRS port number, a transmission comb, an SRS resource mapping (e.g., time and / or frequency resource position, resource offset, resource period, number of repetitions, number of SRS symbols, SRS bandwidth, etc.), hopping-related information, an SRS resource type, a sequence ID, spatial relationship information of the SRS, etc.

[0019] The spatial relationship information of the SRS (e.g., the RRC information element "spatialRelationInfo") may indicate spatial relationship information between a predetermined reference signal and the SRS. The predetermined reference signal may be at least one of a Synchronization Signal / Physical Broadcast Channel (SS / PBCH) block, a Channel State Information Reference Signal (CSI-RS), and an SRS (e.g., another SRS). The SS / PBCH block may be referred to as a Synchronization Signal Block (SSB).

[0020] The spatial relationship information of the SRS may include at least one of an SSB index, a CSI-RS resource ID, and an SRS resource ID as an index of the predetermined reference signal.

[0021] In the present disclosure, the SSB index, SSB resource ID, and SSB Resource Indicator (SSBRI) may be interchangeable. Furthermore, the CSI-RS index, CSI-RS resource ID, and CSI-RS Resource Indicator (CRI) may be interchangeable. Furthermore, the SRS index, SRS resource ID, and SRI may be interchangeable.

[0022] The spatial relationship information of the SRS may include a serving cell index, a BWP index (BWP ID), etc. corresponding to the predetermined reference signal.

[0023] When the UE is configured with spatial relationship information regarding the SRS and an SSB or CSI-RS for a certain SRS resource, the UE may transmit the SRS resource using the same spatial domain filter (spatial domain transmit filter) as the spatial domain filter for receiving the SSB or CSI-RS (spatial domain receive filter). In this case, the UE may assume that the UE receive beam for the SSB or CSI-RS and the UE transmit beam for the SRS are the same.

[0024] When the UE is configured with spatial relationship information between another SRS (reference SRS) and the target SRS for a certain SRS (target SRS), the UE may transmit the target SRS resource using the same spatial domain filter (spatial domain transmit filter) as the spatial domain filter (spatial domain transmit filter) for transmitting the reference SRS. That is, in this case, the UE may assume that the UE transmit beam of the reference SRS and the UE transmit beam of the target SRS are the same.

[0025] The UE may determine the spatial relationship of the PUSCH scheduled by the DCI (e.g., DCI format 0_1) based on the value of a predetermined field (e.g., an SRS resource identifier (SRI) field) in the DCI. Specifically, the UE may use spatial relationship information of the SRS resources (e.g., the RRC information element "spatialRelationInfo") determined based on the value of the predetermined field (e.g., the SRI) for PUSCH transmission.

[0026] In Rel. 15 / 16 NR, when codebook-based transmission is used for PUSCH, the UE is configured by RRC with an SRS resource set of a codebook usage having up to two SRS resources, and one of the up to two SRS resources may be indicated by DCI (a 1-bit SRI field). The transmission beam for PUSCH is specified by the SRI field.

[0027] The UE may determine the TPMI and the number of layers (transmission rank) for the PUSCH based on the precoding information and number of layers field (hereinafter also referred to as the precoding information field). The UE may select a precoder from an uplink codebook for the same number of SRS ports as the number of SRS ports indicated by the upper layer parameter "nrofSRS-Ports" configured for the SRS resource specified by the SRI field based on the TPMI, the number of layers, etc.

[0028] In Rel. 15 / 16 NR, when non-codebook-based transmission is used for PUSCH, a non-codebook-used SRS resource set having up to four SRS resources may be configured for the UE by RRC, and one or more of the up to four SRS resources may be indicated by DCI (a 2-bit SRI field).

[0029] The UE may determine the number of layers (transmission rank) for the PUSCH based on the SRI field. For example, the UE may determine that the number of SRS resources specified by the SRI field is the same as the number of layers for the PUSCH. The UE may also calculate a precoder for the SRS resources.

[0030] If a CSI-RS (which may be referred to as an associated CSI-RS) associated with the SRS resource (or an SRS resource set to which the SRS resource belongs) is configured by a higher layer, the transmission beam for the PUSCH may be calculated based on (measurements of) the configured associated CSI-RS. Otherwise, the transmission beam for the PUSCH may be specified by the SRI.

[0031] The UE may be configured to use codebook-based PUSCH transmission or non-codebook-based PUSCH transmission by a higher layer parameter "txConfig" indicating a transmission scheme. The parameter may indicate a value of "codebook" or "non-codebook."

[0032] In the present disclosure, a codebook-based PUSCH (codebook-based PUSCH transmission, codebook-based transmission) may refer to a PUSCH when a UE is configured with "codebook" as a transmission scheme. In the present disclosure, a non-codebook-based PUSCH (non-codebook-based PUSCH transmission, non-codebook-based transmission) may refer to a PUSCH when a UE is configured with "non-codebook" as a transmission scheme.

[0033] (Determining a PUSCH Precoder in Codebook (CB)-Based Transmission) As described above, in the case of codebook (CB)-based transmission, the UE may determine a precoder for PUSCH transmission based on the SRI, TRI, TPMI, and the like.

[0034] The SRI, TRI, TPMI, etc. may be notified to the UE using Downlink Control Information (DCI). The SRI may be specified by an SRS Resource Indicator field (SRI field) of the DCI, or may be specified by a parameter "srs-ResourceIndicator" included in an RRC information element "ConfiguredGrantConfig" of a configured grant PUSCH.

[0035] The TRI and TPMI may be specified by a "Precoding information and number of layers" field of the DCI, which for simplicity is also referred to as the Precoding information field.

[0036] The UE may report UE capability information related to a precoder type, and the base station may configure the precoder type based on the UE capability information through higher layer signaling. The UE capability information may be information on the precoder type used by the UE in PUSCH transmission (for example, may be represented by the RRC parameter "pusch-TransCoherence").

[0037] The UE may determine the precoder to be used for PUSCH transmission based on precoder type information (e.g., the RRC parameter "codebookSubset") included in PUSCH configuration information notified by higher layer signaling (e.g., the "PUSCH-Config" information element of RRC signaling). The UE may be configured with a subset of the PMI specified by the TPMI by the codebookSubset.

[0038] The precoder type may be specified by any one of full coherent, partial coherent, and non-coherent, or a combination of at least two of these (for example, it may be expressed by parameters such as "fully and partial and non-coherent" or "partial and non-coherent").

[0039] For example, the RRC parameter "pusch-TransCoherence" indicating UE capability may indicate full coherence, partial coherence, or noncoherence, and the RRC parameter "codebookSubset" may indicate "fully and partial and noncoherence," "partial and noncoherence," or "noncoherent."

[0040] Fully coherent may mean that all antenna ports used for transmission are synchronized (may be expressed as being able to match the phase, being able to control the phase for each coherent antenna port, being able to apply a precoder appropriately for each coherent antenna port, etc.). Partially coherent may mean that some of the antenna ports used for transmission are synchronized, but those some ports cannot be synchronized with other ports. Non-coherent may mean that each antenna port used for transmission cannot be synchronized.

[0041] Note that a UE that supports a fully coherent precoder type may be assumed to support partially coherent and non-coherent precoder types, and a UE that supports a partially coherent precoder type may be assumed to support a non-coherent precoder type.

[0042] In the present disclosure, precoder type, coherency, PUSCH transmission coherence, coherence type, coherence type, codebook type, codebook subset, codebook subset type, UE antenna coherence type, antenna coherence assumption, antenna coherence state, and antenna coherency may be read interchangeably.

[0043] The UE may determine, from multiple precoders (which may also be called precoding matrices, codebooks, etc.) for CB-based transmission, a precoding matrix corresponding to a TPMI index obtained from a DCI (e.g., DCI format 0_1, etc.) that schedules an UL transmission.

[0044] Figure 1 shows an example of the association between codebook subsets and TPMI indices. Figure 1 corresponds to a table of precoding matrices W for single-layer (rank-1) transmission using four antenna ports when transform precoding (also called a transform precoder) is disabled in Rel. 16 NR. Figure 1 shows the corresponding Ws in ascending order of TPMI indices from left to right (similar to Figure 2).

[0045] The correspondence relationship (which may be called a table) showing the TPMI index and the corresponding W as shown in Fig. 1 is also called a codebook. A part of this codebook is also called a codebook subset.

[0046] In Fig. 1, if the codebook subset is fully, partially, and non-coherent, the UE is notified of a TPMI (TPMI index) of 0 to 27 for single-layer transmission. If the codebook subset is partial and non-coherent, the UE is configured with a TPMI of 0 to 11 for single-layer transmission. If the codebook subset is non-coherent, the UE is configured with a TPMI of 0 to 3 for single-layer transmission.

[0047] In Fig. 1, when a TPMI of 0 to 3 is notified, a non-coherent precoder is applied. When a TPMI of 4 to 11 is notified, a partially coherent precoder is applied. When a TPMI of 12 to 27 is notified, a fully coherent precoder is applied.

[0048] 2 corresponds to a table of precoding matrices W for two-layer (rank-2) transmission using four antenna ports in Rel. 16 NR when transform precoding is disabled.

[0049] According to Figure 2, the TPMI that the UE is informed of for two-layer transmission is from 0 to 21 (codebook subset full, partial and non-coherent), from 0 to 13 (codebook subset partial and non-coherent) or from 0 to 5 (codebook subset non-coherent).

[0050] Note that a precoding matrix in which only one element per column is non-zero may be called a non-coherent codebook. A precoding matrix in which a certain number of elements per column (greater than one, but not all elements in the column) are non-zero may be called a partially coherent codebook. A precoding matrix in which all elements per column are non-zero may be called a fully coherent codebook.

[0051] The non-coherent codebook and the partially coherent codebook may be called an antenna selection precoder, an antenna port selection precoder, etc. For example, the non-coherent codebook (non-coherent precoder) may be called a 1-port selection precoder, a 1-port port selection precoder, etc. Furthermore, the partially coherent codebook (partially coherent precoder) may be called an x-port (x is an integer greater than 1) selection precoder, an x-port port selection precoder, etc. The fully coherent codebook may be called a non-antenna selection precoder, an all-port precoder, etc.

[0052] In the present disclosure, a partially coherent codebook may correspond to a codebook (precoding matrix) corresponding to a TPMI specified by DCI for codebook-based transmission by a UE configured with a partially coherent codebook subset (e.g., RRC parameter “codebookSubset”=“partialAndNonCoherent”), excluding a codebook corresponding to a TPMI specified by DCI for a UE configured with a non-coherent codebook subset (e.g., RRC parameter “codebookSubset”=“nonCoherent”) (i.e., in the case of single-layer transmission with four antenna ports, a codebook with TPMI=4 to 11).

[0053] In the present disclosure, a fully coherent codebook may correspond to a codebook (precoding matrix) corresponding to a TPMI specified by DCI for codebook-based transmission by a UE configured with a fully coherent codebook subset (e.g., RRC parameter “codebookSubset”=“fullyAndPartialAndNonCoherent”), excluding a codebook corresponding to a TPMI specified by DCI for a UE configured with a partially coherent codebook subset (e.g., RRC parameter “codebookSubset”=“partialAndNonCoherent”) (i.e., in the case of single-layer transmission with four antenna ports, a codebook with TPMI=12 to 27).

[0054] In Rel. 18, at least one of the following UE antenna coherence types is considered for 8 Tx (PUSCH rank greater than 4): Fully coherent, Partially coherent, Non-coherent

[0055] A DMRS port table suitable for the antenna configuration may be defined.

[0056] It is considered that the number of antenna coherent groups (UE antenna groups) Ng can be 1, 2, or 4. The UE assumes that antenna ports within the Ng antenna coherent groups are coherent, and that other antenna ports are non-coherent. When Ng=1, full coherence may be assumed.

[0057] (Multi-panel transmission) In Rel. 18 and later, in order to improve UL throughput / reliability, support for simultaneous UL transmission using multiple panels (e.g., simultaneous multi-panel UL transmission (SiMPUL)) for one or more TRPs is being considered. Also, a multi-panel UL transmission scheme is being considered for a specific UL channel (e.g., PUSCH / PUCCH).

[0058] For example, up to X (e.g., X = 2) and up to Y (e.g., Y = 2) panels may be supported for multi-panel UL transmission. In multi-panel UL transmission, if UL precoding indication for PUSCH is supported, a codebook of a legacy system (e.g., pre-Rel. 16) may be supported for simultaneous multi-panel transmission. Considering single DCI and multi-DCI-based multi-TRP operation, the number of layers may be up to x (e.g., x = 4) across all panels, and the number of codewords (CWs) may be up to y (e.g., y = 2) across all panels.

[0059] At least one of the following methods 1 to 3 (multi-panel UL transmission methods 1 to 3) is being considered as a multi-panel UL transmission method or a candidate multi-panel UL transmission method. Only one of transmission methods 1 to 3 may be supported. Multiple methods including at least one of transmission methods 1 to 3 may be supported, and one of the multiple transmission methods may be configured in the UE.

[0060] <Transmission Scheme 1: Coherent Multi-Panel UL Transmission> Multiple panels may be synchronized with each other. All layers are mapped to all panels. Multiple analog beams are directed. The SRS Resource Indicator (SRI) field may be extended. This scheme may use up to 4 layers for UL.

[0061] In the example of Figure 3A, the UE maps one codeword (CW) or one transport block (TB) to L layers (PUSCH (1, 2, ..., L)) and transmits the L layers from each of two panels. Panels #1 and #2 are coherent. Transmission scheme 1 can obtain diversity gain. The total number of layers in the two panels is 2L. If the maximum total number of layers is 4, the maximum number of layers in one panel is 2.

[0062] <Transmission Scheme 2: Non-coherent Multi-Panel UL Transmission of One Codeword (CW) or Transport Block (TB)> The multiple panels may not be synchronized. Different layers are mapped to one CW or TB for different panels and PUSCHs from multiple panels. A layer corresponding to one CW or TB may be mapped to multiple panels. This transmission scheme may use up to four layers or up to eight layers for the UL. If up to eight layers are supported, this transmission scheme may support one CW or TB using up to eight layers.

[0063] In the example of FIG. 3B, the UE maps 1 CW or 1 TB to k layers (PUSCH(1, 2, ..., k)) and L-k layers (PUSCH(k+1, k+2, ..., L)), transmits k layers from panel #1, and transmits L-k layers from panel #2. Transmission scheme 2 can obtain gains through multiplexing and diversity. The total number of layers in the two panels is L.

[0064] <Transmission Scheme 3: Non-coherent Multi-Panel UL Transmission of Two CWs or TBs> The multiple panels may not be synchronized. Different layers are mapped to different panels and two CWs or TBs for PUSCHs from the multiple panels. A layer corresponding to one CW or TB may be mapped to one panel. Layers corresponding to multiple CWs or TBs may be mapped to different panels. This transmission scheme may use up to four layers or up to eight layers for the UL. When up to eight layers are supported, this transmission scheme may support up to four layers per CW or TB.

[0065] In the example of FIG. 3C , the UE maps CW#1 or TB#1 of the 2CWs or 2TBs to k layers (PUSCH (1, 2, ..., k)), maps CW#2 or TB#2 to L-k layers (PUSCH (k+1, k+2, ..., L)), and transmits k layers from panel #1 and L-k layers from panel #2. Transmission scheme 3 can obtain gains through multiplexing and diversity. The total number of layers in the two panels is L.

[0066] In each of the above transmission schemes, the base station may configure or indicate panel-specific transmission for UL transmission using UL TCI or panel ID. UL TCI (UL TCI state) may be based on signaling similar to DL beam indication supported in Rel. 15. The panel ID may be implicitly or explicitly applied to transmission of at least one of the target RS resource or target RS resource set, PUCCH, SRS, and PRACH. When the panel ID is explicitly signaled, the panel ID may be configured in at least one of the target RS, target channel, and reference RS (e.g., DL RS resource configuration or spatial relationship information).

[0067] In one or more of the transmission methods / modes described above, multi-panel UL transmission (e.g., simultaneous transmission across multiple panels (STxMP)) for scheduling a PUSCH based on one DCI (single DCI) / scheduling a PUSCH based on multiple DCIs (multiple DCIs) is being considered.

[0068] In simultaneous multi-panel transmission (STxMP) in a single DCI-based multi-TRP system, the following schemes may be applied to UL transmissions (e.g., PUSCH): Space Division Multiplexing (SDM): Different layers / DMRS ports of one PUSCH are separately precoded and transmitted simultaneously from different UE beams / panels (see Figures 4A and 4B); SDM repetition: Two PUSCH transmission opportunities with different redundancy versions (RVs) of the same TB are transmitted simultaneously from two different UE beams / panels on the same time and frequency resources (see Figure 4C); and Frequency Division Multiplexing (FDM)-A: Different portions of the frequency domain resources of one PUSCH transmission opportunity (e.g., one PUSCH transmission occasion) are transmitted from different UE beams / panels (see Figure 5A). FDM-B scheme: Two PUSCH transmission opportunities with the same / different RVs of the same TB are transmitted from different UE beams / panels on non-overlapping frequency and time domain resources (see Figure 5B). SFN-based transmission scheme: All the same layers / DMRS ports of one PUSCH are transmitted simultaneously from two different UE beams / panels (see Figure 5C).

[0069] In the present disclosure, the terms "repeated transmission" and "transmission" may be interchangeable. Transmitting multiple TBs may mean transmitting the same TB multiple times or transmitting different TBs.

[0070] Spatial Division Multiplexing (SDM) The UE may assume that SDM-based PUSCH repeat transmissions are scheduled on the same time and frequency resources, i.e., the UE may transmit SDM-based PUSCH repeat transmissions on the same time and frequency resources when using coherent panels.

[0071] 4A is a diagram showing an example of repeated transmission using SDM in one CW, in which the time and frequency resources of layers #1-2 and #3-4 corresponding to the PUSCH / PUCCH are the same.

[0072] 4B is a diagram showing an example of repeated transmission using SDM in two CWs. In this example, CW#1 and CW#2 corresponding to PUSCH / PUCCH have the same time and frequency resources.

[0073] 4C is a diagram showing an example of repeated transmission using SDM, in which the time and frequency resources of PUSCH / PUCCH repetitions #1 and #2 are the same.

[0074] Note that PUSCH transmission to which SDM is applied (for example, PUSCH repeated transmission) may be configured such that at least a portion of the time and frequency resources overlap.

[0075] Frequency Division Multiplexing (FDM) The UE may assume that PUSCH / PUCCH repeat transmissions employing Frequency Division Multiplexing (FDM) are scheduled on the same time resources but different frequency resources, i.e., the UE may transmit PUSCH / PUCCH repeat transmissions employing FDM on the same time resources but different frequency resources when using coherent panels.

[0076] 5A is a diagram showing a first example of repeated transmission using FDM (FDM-A), in which one PUSCH / PUCCH repeated transmission is performed for one TB / UCI.

[0077] 5B is a diagram showing a second example of repeated transmission using FDM (FDM-B), in which PUSCH / PUCCH repeated transmission is performed twice per TB / UCI.

[0078] 5C is a diagram illustrating an example of repeated transmission using a single frequency network (SFN), in which one PUSCH / PUCCH is transmitted using a different beam / panel for one TB / UCI.

[0079] [STxMP] SDM (transmitting separate MIMO layers from multiple panels) is being considered to improve UL throughput. SFN-based repetition is being considered to improve UL reliability. This method is effective when the beam is blocked by disturbances in FR2.

[0080] In the single DCI-based STxMP PUSCH SDM (STxMP SDM) scheme, two SRS resource sets are configured for CB or NCB. In the codebook-based PUSCH, the DCI indicates two TPMI fields, each of which indicates precoding information and the number of layers transmitted across the SRS ports of the indicated SRS resource set within each SRS resource set. In the non-codebook-based PUSCH and the codebook-based PUSCH, the DCI indicates two SRI fields, each of which indicates the SRS resource for each SRS resource set.

[0081] In Rel. 18, it is considered to support an SFN-based transmission scheme for STxMP PUSCH transmission in a single DCI-based multi-TRP system.

[0082] (DMRS) The front-loaded DMRS is the first DMRS (at or near the first symbol) for faster demodulation. An additional DMRS can be configured by RRC for fast-moving UEs or high modulation and coding scheme (MCS) / rank. The frequency location of the additional DMRS is the same as that of the front-loaded DMRS.

[0083] For the time domain, DMRS mapping type A or B is configured. In DMRS mapping type A, DMRS position l_0 is counted by the symbol index within the slot. l_0 is configured by the parameter (dmrs-TypeA-Position) in the MIB or common serving cell configuration (ServingCellConfigCommon). DMRS position 0 (reference point l) refers to the first symbol of the slot or each frequency hop. In DMRS mapping type B, DMRS position l_0 is counted by the symbol index within the PDSCH / PUSCH. l_0 is always 0. DMRS position 0 (reference point l) refers to the first symbol of the PDSCH / PUSCH or each frequency hop.

[0084] The DMRS location is defined by a table in the specification and depends on the duration of the PDSCH / PUSCH. The location of the additional DMRS is fixed.

[0085] For the frequency domain, (PDSCH / PUSCH) DMRS configuration type 1 or type 2 is configured. DMRS configuration type 1 has a comb structure and is applicable to both Cyclic Prefix Orthogonal Frequency Division Multiplexing (CP-OFDM) and Discrete Fourier Transform Spread OFDM (DFT-s-OFDM). DMRS configuration type 2 is applicable only to CP-OFDM.

[0086] Note that CP-OFDM may be used when transform precoding (which may also be referred to as a transform precoder) is disabled (the parameter of the transform precoder (e.g., transformPrecoder) = "disabled"), and DFT-S-OFDM may be used when the parameter of the transform precoder (e.g., transformPrecoder) = "enabled").

[0087] Single symbol DMRS or double symbol DMRS may be configured in the UE.

[0088] Single-symbol DMRS is normally used (it is a mandatory feature in Rel. 15). In single-symbol DMRS, the number of additional DMRS (symbols) is {0, 1, 2, 3}. Single-symbol DMRS supports both frequency hopping enabled and disabled. If the maxLength in the uplink DMRS configuration (DMRS-UplinkConfig) is not configured, single-symbol DMRS is used.

[0089] Double-symbol DMRS is used for more DMRS ports (especially MU-MIMO). In double-symbol DMRS, the number of additional DMRS (symbols) is {0, 1}. Double-symbol DMRS is supported when frequency hopping is disabled. If the maximum length (maxLength) in the uplink DMRS configuration (DMRS-UplinkConfig) is 2 (len2), whether it is single-symbol DMRS or double-symbol DMRS is determined by the DCI or configured grant.

[0090] From the above, the possible DMRS configuration patterns are the following combinations: DMRS configuration type 1, DMRS mapping type A, single symbol DMRS DMRS configuration type 1, DMRS mapping type A, double symbol DMRS DMRS configuration type 1, DMRS mapping type B, single symbol DMRS DMRS configuration type 1, DMRS mapping type B, double symbol DMRS DMRS configuration type 2, DMRS mapping type A, single symbol DMRS DMRS configuration type 2, DMRS mapping type A, double symbol DMRS DMRS configuration type 2, DMRS mapping type B, single symbol DMRS DMRS configuration type 2, DMRS mapping type B, double symbol DMRS

[0091] Multiple DMRS ports that are mapped to the same RE (Time and Frequency Resource) may be referred to as a DMRS Code Division Multiplexing (CDM) group.

[0092] For DMRS configuration type 1 and single-symbol DMRS, four DMRS ports can be used. Within each DMRS CDM group, two DMRS ports are multiplexed using FD OCC of length 2. Between multiple DMRS CDM groups (two DMRS CDM groups), two DMRS ports are multiplexed using FDM.

[0093] For DMRS configuration type 1 and double-symbol DMRS, eight DMRS ports can be used. Within each DMRS CDM group, two DMRS ports are multiplexed by an FD OCC of length 2, and two DMRS ports are multiplexed by a TD OCC. Between multiple DMRS CDM groups (two DMRS CDM groups), two DMRS ports are multiplexed by FDM.

[0094] For DMRS configuration type 2 and single-symbol DMRS, six DMRS ports can be used. Within each DMRS CDM group, two DMRS ports are multiplexed using an FD OCC of length 2. Between multiple DMRS CDM groups (three DMRS CDM groups), three DMRS ports are multiplexed using FDM.

[0095] For DMRS configuration type 2 and double-symbol DMRS, 12 DMRS ports can be used. Within each DMRS CDM group, two DMRS ports are multiplexed by an FD OCC of length 2, and two DMRS ports are multiplexed by a TD OCC. Between multiple DMRS CDM groups (three DMRS CDM groups), three DMRS ports are multiplexed by FDM.

[0096] Here, an example of DMRS mapping type B is shown, but DMRS mapping type A is also similar.

[0097] 6 is a diagram illustrating an example of parameters for PDSCH DMRS. For DMRS configuration type 1, DMRS ports 1000-1007 can be used, and for DMRS configuration type 2, DMRS ports 1000-1011 can be used.

[0098] 7 is a diagram illustrating an example of parameters for PUSCH DMRS. For DMRS configuration type 1, DMRS ports 0-7 can be used, and for DMRS configuration type 2, DMRS ports 0-11 can be used.

[0099] (DMRS Port Restrictions in DL Multi-TRP) In DL multi-TRP in Rel. 16, multiple DMRS ports corresponding to different TRPs are instructed not to be in the same CDM group. This can avoid interference between multiple DMRSs from different TRPs with different power differences when orthogonality between the multiple DMRS ports is lost due to factors such as frequency selectivity. Figure 8 shows an example of an antenna port indication table for PDSCH when DMRS configuration type 1 and DMRS maximum length = 1 are specified. For CDM groups 0 and 1, two DMRS ports and one DMRS port, or one DMRS port and two DMRS ports, can be specified.

[0100] (Ports of Reference Signals) For orthogonalization of MIMO layers, reference signals of multiple ports (for example, demodulation reference signals (DMRS) and CSI-RS) are used.

[0101] For example, for single user MIMO (SU-MIMO), a different DMRS port / CSI-RS port may be set for each layer. For multi user MIMO (MU-MIMO), a different DMRS port / CSI-RS port may be set for each layer within one UE and for each UE.

[0102] In addition, if the number of CSI-RS ports is greater than the number of layers used for data, it is possible to measure the channel state more accurately based on this CSI-RS, which is expected to contribute to improving throughput.

[0103] In Rel. 15 NR, multiple-port DMRS is supported using frequency division multiplexing (FDM), frequency domain orthogonal cover code (FD-OCC), time domain OCC (TD-OCC), etc., with up to eight ports for Type 1 DMRS (i.e., DMRS configuration type 1) and up to 12 ports for Type 2 DMRS (i.e., DMRS configuration type 2).

[0104] In Rel. 15 NR, a comb-like transmission frequency pattern (comb-like resource set) is used for the FDM. Cyclic Shift (CS) is used for the FD-OCC. Furthermore, the TD-OCC can only be applied to double-symbol DMRS.

[0105] The OCC in the present disclosure may be interchangeably read as orthogonal code, orthogonalization, cyclic shift, and the like.

[0106] The type of DMRS may be referred to as a DMRS configuration type.

[0107] Among DMRSs, DMRSs that are resource mapped in units of two consecutive (adjacent) symbols may be called double-symbol DMRSs, and DMRSs that are resource mapped in units of one symbol may be called single-symbol DMRSs.

[0108] Either DMRS may be mapped to one or more symbols per slot depending on the length of the data channel. A DMRS mapped to the beginning of a data symbol may be called a front-loaded DMRS, and a DMRS additionally mapped to other positions may be called an additional DMRS.

[0109] In the case of DMRS configuration type 1 and single-symbol DMRS, Comb and CS may be used for orthogonalization. For example, up to four antenna ports (APs) may be supported by using two types of Comb and two types of CS (Comb2+2CS).

[0110] In the case of DMRS configuration type 1 and double-symbol DMRS, the comb, CS, and TD-OCC may be used for orthogonalization. For example, up to eight APs may be supported using two types of comb, two types of CS, and TD-OCC ({1,1} and {1,-1}).

[0111] In the case of DMRS configuration type 2 and single-symbol DMRS, FD-OCC may be used for orthogonalization. For example, up to six APs may be supported by applying an orthogonal code (2-FD-OCC) to two adjacent resource elements (REs) in the frequency direction.

[0112] In the case of DMRS configuration type 2 and double-symbol DMRS, FD-OCC and TD-OCC may be used for orthogonalization. For example, up to 12 APs may be supported by applying an orthogonal code (2-FD-OCC) to two adjacent REs in the frequency direction and a TD-OCC ({1,1} and {1,-1}) to two adjacent REs in the time direction.

[0113] In addition, in Rel. 15 NR, a maximum of 32 ports of the multi-port CSI-RS are supported by using FDM, time division multiplexing (TDM), frequency domain OCC, time domain OCC, etc. The same method as that for the above-mentioned DMRS may also be applied to orthogonalization of the CSI-RS.

[0114] Now, a group of DMRS ports orthogonalized by the FD-OCC / TD-OCC as described above is also called a Code Division Multiplexing (CDM) group.

[0115] Different CDM groups are orthogonal because they are FDM-encoded. However, within the same CDM group, the orthogonality of the applied OCC may be lost due to channel fluctuations, etc. In this case, if signals within the same CDM group are received with different reception powers, a near-far problem may occur, and orthogonality may not be guaranteed.

[0116] Here, we will explain the TD-OCC / FD-OCC of DMRS in Rel. 15 NR. The DMRS mapped to a resource element (RE) is a DMRS sequence with FD-OCC parameters (which may also be called sequence elements) w ｆ (k') and the TD-OCC parameters (which may also be called sequence elements) w ｔ (l') and may correspond to a sequence obtained by multiplying (l') and (l').

[0117] The TD-OCC and FD-OCC of the DMRS of Rel. 15 NR both correspond to OCCs with a sequence length (which may also be referred to as the OCC length) of 2. Therefore, the possible values ​​of k' and l' above are both 0 and 1. By multiplying this FD-OCC in RE units, two-port DMRS can be multiplexed using the same time and frequency resources (2 RE). When both the FD-OCC and TD-OCC are applied, four-port DMRS can be multiplexed using the same time and frequency resources (4 RE).

[0118] The two existing DMRS port tables for PDSCH described above correspond to DMRS configuration type 1 and type 2, respectively. Note that p indicates the antenna port number, and Δ indicates a parameter for shifting (offsetting) the frequency resource.

[0119] For example, for antenna ports 1000 and 1001, {w ｆ (0), w ｆ (1)} = {+1, +1} and {w ｆ (0), w ｆ (1)}={+1, -1} is applied to the vectors, and the vectors are orthogonalized using FD-OCC.

[0120] FDM is applied to antenna ports 1000-1001 and antenna ports 1002-1003 (and also antenna ports 1004-1005 in the case of Type 2) by applying different values ​​of Δ. Thus, antenna ports 1000-1003 (or 1000-1005) corresponding to single-symbol DMRS are orthogonalized using FD-OCC and FDM.

[0121] For the antenna ports 1000-1003 and the antenna ports 1004-1007 of type 1, {w ｔ (0), w ｔ (1)} = {+1, +1} and {w ｔ (0), w ｔ (1)}={+1, −1} is applied, and thus the antenna ports 1000-1007 (or 1000-1011) corresponding to the double-symbol DMRS are orthogonalized using FD-OCC, TD-OCC, and FDM.

[0122] For CP-OFDM only, it is considered to specify a larger number of orthogonal DMRS ports for DL / UL MU-MIMO (without increasing DMRS overhead), a common design between DL and UL DMRS, up to 24 orthogonal DMRS ports, and doubling the maximum number of orthogonal DMRS ports for both single-symbol DMRS and double-symbol DMRS for each applicable DMRS configuration type.

[0123] In Rel. 15, the following Cases 1 to 4 can be configured. [Case 1] The total number of single-symbol DMRS ports in DMRS configuration type 1 is 2 (by comb / FDM) × (by FD OCC) 2 = 4 ports. [Case 2] The total number of double-symbol DMRS ports in DMRS configuration type 1 is 2 (by comb / FDM) × (by FD OCC) 2 × (by TD OCC) 2 = 8 ports. [Case 3] The total number of single-symbol DMRS ports in DMRS configuration type 2 is 3 (by FDM) × (by FD OCC) 2 = 6 ports. [Case 4] The total number of double-symbol DMRS ports in DMRS configuration type 2 is 3 (by comb) × (by FD OCC) 2 × (by TD OCC) 2 = 12 ports.

[0124] Furthermore, in Cases 1 to 4 of Rel. 15, the mapping of CDM groups and DMRS port indices is as follows:

[0125] [Case 1] Four ports and two CDM groups may be available. For the PUSCH, CDM group #0 may correspond to DMRS port indices {0,1}, and CDM group #1 may correspond to DMRS port indices {2,3}. For the PDSCH, CDM group #0 may correspond to DMRS port indices {1000,1001}, and CDM group #1 may correspond to DMRS port indices {1002,1003}.

[0126] [Case 2] Eight ports and two CDM groups may be available. For the PUSCH, CDM group #0 may correspond to DMRS port indices {0, 1, 4, 5}, and CDM group #1 may correspond to DMRS port indices {2, 3, 6, 7}. For the PDSCH, CDM group #0 may correspond to DMRS port indices {1000, 1001, 1004, 1005}, and CDM group #1 may correspond to DMRS port indices {1002, 1003, 1006, 1007}.

[0127] [Case 3] Six ports and three CDM groups may be available. For the PUSCH, CDM group #0 may correspond to DMRS port index {0,1}, CDM group #1 may correspond to DMRS port index {2,3}, and CDM group #2 may correspond to DMRS port index {4,5}. For the PDSCH, CDM group #0 may correspond to DMRS port index {1000,1001}, CDM group #1 may correspond to DMRS port index {1002,1003}, and CDM group #2 may correspond to DMRS port index {1004,1005}.

[0128] [Case 4] 12 ports and 3 CDM groups may be available. For the PUSCH, CDM group #0 may correspond to DMRS port indices {0, 1, 6, 7}, CDM group #1 may correspond to DMRS port indices {2, 3, 8, 9}, and CDM group #2 may correspond to DMRS port indices {4, 5, 10, 11}. For the PDSCH, CDM group #0 may correspond to DMRS port indices {1000, 1001, 1006, 1007}, CDM group #1 may correspond to DMRS port indices {1002, 1003, 1008, 1009}, and CDM group #2 may correspond to DMRS port indices {1004, 1005, 1010, 1011}.

[0129] In Rel. 18, it is considered to double the total number of DMRS ports to 8, 16, 12, and 24 for Cases 1, 2, 3, and 4, respectively.

[0130] To increase the number of DMRS ports, the following five options (methods for increasing the number of DMRS ports) are being considered.

[0131] <Option 1> - Introducing a new OCC with a length greater than that of the existing OCC (for example, 4 or 6). In Option 1, the following issues need to be considered: possible performance degradation when the delay spread is large, possible scheduling restrictions, and backward compatibility.

[0132] <Option 2> Use of TD-OCC on multiple discontinuous DMRS symbols (e.g., TD-OCC on front-loaded DMRS / additional DMRS). Option 2 addresses the following issues: possible performance degradation when UE speed is high, possible scheduling limitations (e.g., frequency hopping application method), possible limitations on DMRS configuration (e.g., limited number of additional DMRS), and backward compatibility.

[0133] <Option 3> - Increase the number of CDM groups (for example, increase the number of comb / FDM). In option 3, the possibility of performance degradation when the delay spread is large and backward compatibility are considered.

[0134] <Option 4> Reuse symbols for additional DMRS and increase the number of orthogonal DMRS ports. Option 4 has several issues to consider, including the possibility of performance degradation when UE speed is high, the possibility of DMRS configuration being limited (e.g., the number of additional DMRS is limited), and backward compatibility.

[0135] <Option 5> Use of TD-OCC on discontinuous multiple DMRS symbols combined with FD-OCC / FDM (reusing symbols of additional DMRS to improve channel estimation performance). Option 5 addresses the following issues: possible performance degradation at high UE speeds, possible scheduling limitations (e.g., frequency hopping application method), possible limitations on DMRS configuration (e.g., limited number of additional DMRS), and backward compatibility.

[0136] In Option 1, the new FD-OCC for DMRS of PDSCH / PUSCH may follow at least one of the following options for new DMRS configuration type 1: <<Option 1-1>> A new FD-OCC of length 6 is applied to 6 REs of DMRS in one PRB in one CDM group. <<Option 1-2>> A new FD-OCC of length 4 is applied to 4 REs of DMRS in one PRB or across multiple consecutive PRBs in one CDM group.

[0137] In Option 1, the new FD-OCC for DMRS of PDSCH / PUSCH has a length of 4 and is applied to 4 REs of DMRS in one PRB in one CDM group for new DMRS configuration type 2. A new FD-OCC of length 6 may also be supported for new DMRS configuration type 2.

[0138] In the present disclosure, existing FD-OCC#0=[+1 +1] and existing FD-OCC#1=[+1 -1] may also be used.

[0139] The new FD-OCC may be any of several OCCs:

[0140] [OCC-a] OCC of length 4 based on a 4x4 Walsh matrix (sequence). As in the example of Figure 9A, four sequences are obtained for OCC index i={0, 1, 2, 3}.

[0141] [OCC-b] Length-4 OCC based on cyclic shift. As shown in the example in Fig. 9B, for OCC index i = {0, 1, 2, 3}, four sequences are obtained by using cyclic shifts {i·0, i·π / 2, i·π, i·3π / 2}.

[0142] [OCC-c] As in the example of FIG. 9C, the OCCs with OCC indexes 1 and 2 in OCC-b are exchanged.

[0143] [OCC-d] OCC of length 6 based on FFT (DFT). As shown in the example of Fig. 9D, for OCC index i = {0,1,2,3,4,5}, six sequences are obtained from each row of the DFT matrix.

[0144] [OCC-e] Like OCC-a and OCC-c, an OCC of length 4 consisting of a repetition of an OCC (existing FD-OCC) of length 2. As in the example of Fig. 10, the first and second halves of length 4 OCCs #0 and #1 (OCCs corresponding to OCC indexes 0 and 1) are the same as length 2 OCCs #0 and #1 (OCCs corresponding to OCC indexes 0 and 1), respectively.

[0145] In this disclosure, the OCC (FD-OCC / TD-OCC) corresponding to OCC index i may be referred to as OCC#i.

[0146] Some of the multiple sequences of the new FD-OCC may be associated with existing DMRS port indices.

[0147] If a length 2 FD-OCC is used, the existing DMRS port table may be used.

[0148] If the new FD-OCC is OCC-e, the new DMRS port table for DMRS configuration type 1 may be the DMRS port table in FIG. 11 . The new DMRS port table may indicate the DMRS ports (p is 0 or greater) corresponding to the new FD-OCC. At least some of the values ​​of p in the new DMRS port table may overlap with the values ​​of p in the existing DMRS port table. If the use of the new FD-OCC is configured / instructed, the UE may use the new DMRS port table, and if the use of the new FD-OCC is not configured / instructed, the UE may use the existing DMRS port table. As in this example, the same DMRS port index (0 to 7 for the existing DMRS port, DMRS configuration type 1) as the existing DMRS port may be used for the DMRS ports associated with the new FD-OCCs #0 and #1. For DMRS ports with new FD-OCC #2, 3, a different DMRS port index (8 to 15 for new DMRS ports, DMRS setting type 1) may be used than for existing DMRS ports.

[0149] Some of the multiple sequences of the new FD-OCC may not be associated with existing DMRS port indices.

[0150] As shown in the example of Fig. 12, the new DMRS port table may indicate only the DMRS ports corresponding to the new FD-OCCs. The DMRS port indexes corresponding to the new FD-OCCs may not overlap with the DMRS port indexes corresponding to the existing FD-OCCs.

[0151] 13, a new DMRS port table may include a DMRS port corresponding to an existing FD-OCC and a DMRS port corresponding to a new FD-OCC, and in the new DMRS port table, the DMRS port index corresponding to the new FD-OCC may be added after the DMRS port index corresponding to the existing FD-OCC.

[0152] If the new FD-OCC is OCC-e, the new DMRS port table for DMRS setting type 2 may be the DMRS port table of FIG. 14 or may follow the same rules as those of FIG. 12 and FIG. 13.

[0153] (Analysis) As described above, DMRS ports that can support a number of layers greater than four are being considered for Rel. 18 NR. Also, for Rel. 18 NR, increasing the number of orthogonal DMRS ports for PUSCH / PDSCH is being considered. Such new DMRS ports, which differ from existing DMRS ports (also called Rel. 15 DMRS ports), are also called Rel. 18 DMRS ports, extended DMRS ports, etc.

[0154] The maximum number of ports for DMRS type=1 and single-symbol DMRS may increase from four in Rel. 15 DMRS to eight in Rel. 18 DMRS.

[0155] The maximum number of ports for DMRS type=1 and double-symbol DMRS may increase from 8 in Rel. 15 DMRS to 16 in Rel. 18 DMRS.

[0156] The maximum number of ports for DMRS type=2 and single-symbol DMRS may increase from 6 in Rel. 15 DMRS to 12 in Rel. 18 DMRS.

[0157] The maximum number of ports for DMRS type=2 and double-symbol DMRS may increase from 12 in Rel. 15 DMRS to 24 in Rel. 18 DMRS.

[0158] Such an increase in the number of DMRS ports may be achieved using at least one of the following: FD-OCC extension: using an OCC length (e.g., 4, 6, etc.) greater than the Rel. 15 OCC length (=2); TD-OCC extension: using a TD-OCC spanning non-contiguous DMRS symbols (e.g., TD-OCC spanning preceding / additional DMRS); Sparse frequency allocation: increasing the number of CDM groups (e.g., increasing the number of combs / FDMs); Using TDMed DMRS symbols: using / reusing additional DMRS symbols to increase the number of orthogonal DMRS ports.

[0159] For PUSCH with more than four layers, it is considered that a new antenna port indication table for ranks 5 / 6 / 7 / 8 will be supported for single-symbol DMRS and double-symbol DMRS, respectively.

[0160] The antenna port indication table for Rel. 15 DMRS ports for DMRS configuration type 1 / DMRS configuration type 2 may follow at least one of the following options: [Option 1-1] The same combination of DMRS ports (p) as the combination of DMRS ports (1000 + p) for PDSCH ranks = 5, 6, 7, and 8 is used, at least for fully coherent or non-coherent UL codebooks. [Option 1-2] A new combination of DMRS ports for ranks = 5, 6, 7, and 8 is used.

[0161] The antenna port indication table for Rel. 18 DMRS ports in Extended DMRS Configuration Type 1 / Extended DMRS Configuration Type 2 uses new combinations of DMRS ports for ranks 5, 6, 7, and 8. The new combinations of DMRS ports may allow single-symbol DMRS for ranks 5, 6, 7, and 8. The new combinations of DMRS ports may not exclude existing combinations of DMRS ports in Rel. 15-17.

[0162] In STxMP, it is being considered whether antenna ports on different panels can be configured to the same CDM group. If antenna ports on different panels cannot be configured to the same CDM group in STxMP, a DMRS port table may be defined that indicates different CDM groups to antenna ports on different panels (corresponding to different ULs / joint TCIs). The DMRS port table may be defined for ranks 1 / 2 / 3 / 4 or for more ranks. If antenna ports on different panels can be configured to the same CDM group in STxMP, a DMRS port table may be defined regardless of whether different CDM groups are indicated to antenna ports on different panels (corresponding to different ULs / joint TCIs).

[0163] In 8Tx, the question is whether antenna ports on different panels can be configured to the same CDM group. If antenna ports on different panels cannot be configured to the same CDM group in 8Tx, a DMRS port table may be defined that indicates different CDM groups to antenna ports on different panels (corresponding to different UL / joint TCI). The DMRS port table may be defined for ranks 5 to 8, or may further be defined for ranks 1 to 4. If antenna ports on different panels can be configured to the same CDM group in 8Tx, a DMRS port table may be defined regardless of whether different CDM groups are indicated to antenna ports on different panels (corresponding to different UL / joint TCI).

[0164] However, it is unclear what antenna port indication table is used for whether Rel. 15 or Rel. 18 DMRS ports are used and whether the rank is 1 / 2 / 3 / 4 or 5 / 6 / 7 / 8.

[0165] Therefore, the present inventors have devised a method for indicating antenna ports when Rel. 18 DMRS ports are defined.

[0166] Hereinafter, embodiments according to the present disclosure will be described in detail with reference to the drawings. Wireless communication methods according to the embodiments may be applied independently or in combination.

[0167] In the present disclosure, "A / B" and "at least one of A and B" may be interpreted interchangeably. Also, in the present disclosure, "A / B / C" may mean "at least one of A, B, and C."

[0168] In the present disclosure, terms such as notify, activate, deactivate, indicate (or indicate), select, configure, update, and determine may be read interchangeably. In the present disclosure, terms such as support, control, controllable, operate, and operate may be read interchangeably.

[0169] In the present disclosure, Radio Resource Control (RRC), RRC parameters, RRC messages, higher layer parameters, fields, information elements (IEs), settings, etc. may be interchangeable. In the present disclosure, Medium Access Control (MAC) control elements (CEs), update commands, activation / deactivation commands, etc. may be interchangeable.

[0170] In the present disclosure, higher layer signaling may be, for example, any one of Radio Resource Control (RRC) signaling, Medium Access Control (MAC) signaling, broadcast information, and the like, or a combination thereof.

[0171] In the present disclosure, MAC signaling may use, for example, a MAC Control Element (MAC CE), a MAC Protocol Data Unit (PDU), etc. Broadcast information may be, for example, a Master Information Block (MIB), a System Information Block (SIB), Remaining Minimum System Information (RMSI), Other System Information (OSI), etc.

[0172] In the present disclosure, physical layer signaling may be, for example, Downlink Control Information (DCI), Uplink Control Information (UCI), and the like.

[0173] In the present disclosure, the terms index, identifier (ID), indicator, resource ID, etc. may be interchangeable. In the present disclosure, the terms sequence, list, set, group, cluster, subset, etc. may be interchangeable.

[0174] In the present disclosure, the terms panel, UE panel, panel group, beam, beam group, precoder, Uplink (UL) transmitting entity, Transmission / Reception Point (TRP), base station, Spatial Relation Information (SRI), spatial relation, SRS Resource Indicator (SRI), Control Resource Set (CORESET), Physical Downlink Shared Channel (PDSCH), Codeword (CW), Transport Block (TB), Reference Signal (RS), antenna port (e.g., Demodulation Reference Signal (DMRS) port), antenna port group (e.g., DMRS port group), group (e.g., spatial relation group, Code Division Multiplexing (CDM) group, reference signal group, CORESET group, Physical Uplink Control Channel (PUCCH) group, PUCCH resource group), resource (e.g., reference signal resource, SRS resource), resource set (e.g., reference signal resource set), CORESET pool, downlink Transmission Configuration Indication state (TCI state) (DL TCI state), uplink TCI state (UL TCI state), unified TCI state, common TCI state, Quasi-Co-Location (QCL), QCL assumption, etc. may be read as interchangeable.

[0175] In this disclosure, the notation "Rel. XX" indicates a 3GPP release. However, the release number "XX" is an example and may be replaced with another number.

[0176] In the present disclosure, DMRS, DL DMRS, UL DMRS, PDSCH DMRS, and PUSCH DMRS may be read as interchangeable terms.

[0177] In the present disclosure, orthogonal sequence, OCC, FD OCC, and TD OCC may be interpreted as interchangeable.

[0178] In the present disclosure, the terms DMRS port, antenna port, port, and DMRS port index may be interchangeable. In the present disclosure, the terms DMRS CDM group, CDM group, DMRS group, DMRS CDM group(s) without data, etc. may be interchangeable. In the present disclosure, the terms antenna port indication and antenna port field may be interchangeable. In the present disclosure, the terms DMRS configuration type, DMRS type, and the RRC parameter "dmrs-Type" may be interchangeable. In the present disclosure, the terms maximum DMRS length, maximum number of DMRS symbols, number of DMRS symbols, and the RRC parameter "maxLength" may be interchangeable.

[0179] In the present disclosure, DMRS type 1 (or DMRS type = 1) may mean that the RRC parameter "dmrs-Type" is not set (e.g., the RRC parameter "dmrs-Type" is absent in the DMRS configuration (DMRS-DownlinkConfig information element / DMRS-UplinkConfig information element)), or may mean that 1 (or type 1) is set as the RRC parameter related to the DMRS type.

[0180] In the present disclosure, the maximum length of DMRS=1 may mean that the RRC parameter "maxLength" is not set (e.g., the RRC parameter "maxLength" is absent in the DMRS configuration (DMRS-DownlinkConfig information element / DMRS-UplinkConfig information element)), or that the RRC parameter regarding the maximum length of DMRS is set to 1 (or length 1 (len1)).

[0181] In the present disclosure, the terms CDM group list, port group list, and list may be interchangeable. In the present disclosure, the terms CDM group subset, port group subset, and group subset may be interchangeable.

[0182] In the present disclosure, the terms rank, transmission rank, number of layers, and number of antenna ports may be interchangeable. Furthermore, the terms "one codeword is applied" and "the number of layers is four or less" may be interchangeable. The terms "two codewords are applied" and "the number of layers is greater than four" may be interchangeable.

[0183] In the present disclosure, "transform precoding is configured" may be read interchangeably as "transform precoding is enabled."

[0184] It should be noted that in this disclosure, "having the capability of..." may be read interchangeably as "supporting / reporting the capability of...".

[0185] In the present disclosure, a table may be read interchangeably as one or more tables.

[0186] In the present disclosure, STxMP, SiMPUL, simultaneous transmission using multiple panels, simultaneous multi-panel transmission, and simultaneous multi-panel UL transmission may be interchangeable. Furthermore, STxMP may mean instructing / configuring multiple joint / UL TCI states, spatial relations, and beams for one PUSCH / PUCCH / SRS. In the present disclosure, supporting and configuring / instructing may be interchangeable. In the present disclosure, transmit power and output power may be interchangeable. In the present disclosure, determining by the UE and configuring / instructing by the network (base station / gNB) may be interchangeable.

[0187] In the present disclosure, UL panel, UE panel, (same) antenna coherent group, UL / joint TCI, spatial relationship, PL-RS, and (same) destination TRP may be read interchangeably.

[0188] In the present disclosure, 8Tx and UL transmission of more than four layers / ranks may be read interchangeably.

[0189] In this disclosure, the terms Rel. 15 DMRS port, Rel. 15 Type 1 / 2 DMRS port, and existing DMRS port may be interchangeable. In this disclosure, the terms Rel. 18 DMRS port, Rel. 18 Extended Type 1 / 2 DMRS port, and new DMRS port may be interchangeable.

[0190] In the present disclosure, the Rel. 15 DMRS configuration type, DMRS configuration type, and type may be interchangeable, and the Rel. 18 DMRS configuration type, extended DMRS configuration type, extended type, and e-type may be interchangeable.

[0191] In the present disclosure, the terms "antenna port table" and "antenna port indication table" may be interchangeable. In the present disclosure, the terms "DMRS port combination," "combination of DMRS ports," and "one or more DMRS ports corresponding to one value in the antenna port field" may be interchangeable.

[0192] Furthermore, DCI in the following embodiments may refer to DCI that schedules PUSCH (for example, DCI format 0_x (where x is an integer)).

[0193] (Wireless Communication Method) <Embodiment #0> For a certain rank, an antenna port indication table for Rel. 15 DMRS ports and an antenna port indication table for Rel. 18 DMRS ports may be defined, and these antenna port indication tables may be switched by an RRC IE / MAC CE / DCI. An antenna port indication table for a certain rank and DMRS configuration type x and an antenna port indication table for that rank and extended DMRS configuration type x may be defined, and these antenna port indication tables may be switched by an RRC IE / MAC CE / DCI. x may be 1 or 2.

[0194] It may be specified that when the DMRS port for PUSCH is indicated by the antenna port field in DCI format 0_1 / 0_2, the UE assumes that the indicated DMRS port varies depending on the UE's antenna coherence assumption.

[0195] For example, two different antenna coherence assumptions may be cases A and B. Cases A / B may be related to UL panels, such as at least one of full coherence, partial coherence, and non-coherence, antenna coherence groups, and the number of UL panels. For example, case A may be full coherence / non-coherence, and case B may be partial coherence.

[0196] Multiple antenna port indication tables may be applied to multiple different antenna coherence assumptions. For a certain DMRS configuration type and a certain DMRS maximum length, an antenna port indication table for case A as shown in the example of FIG. 15A and an antenna port indication table for case B as shown in the example of FIG. 15B may be defined. The number and contents of the entries in the antenna port indication table are not limited to this example. The contents of the antenna port indication table for case A may be different from the contents of the antenna port indication table for case B as shown in the example of FIG. 15B. The UE may select an antenna port indication table corresponding to the antenna coherence assumption, or the antenna port indication table may be configured by higher layer signaling.

[0197] A common antenna port indication table may be applied to multiple different antenna coherence assumptions. When two different antenna coherence assumptions are cases A and B, antenna port indication tables for cases A and B, such as the example of FIG. 16 , may be defined for a certain DMRS configuration type and a certain DMRS maximum length. The antenna port field value may correspond to one of multiple antenna coherence assumptions. In this example, antenna port field values ​​0 and 1 may correspond to case A, and antenna port field values ​​2 and 3 may correspond to case B.

[0198] According to this embodiment, the UE can be instructed on the appropriate antenna port for the antenna coherence assumption.

[0199] <Embodiment #1> When the DMRS port for PUSCH is indicated by the antenna port field in DCI format 0_1 / 0_2, the indicated DMRS port may follow at least one of the following options.

[0200] [Option 1-1] The UE does not assume that different DMRS ports corresponding to different UL panels are configured in the same CDM group. This option may be applied when the UE reports specific UE capabilities and / or when configured / indicated by specific RRC IE / MAC CE / DCI. For example, this option may be applied when the UE reports at least one of 8Tx capability and STxMP SDM capability. For example, this option may be applied when the UE is instructed to use a specific precoder / TPMI.

[0201] [Option 1-2] The UE also assumes that different DMRS ports corresponding to different UL panels are configured in the same CDM group. This option may be applied when the UE reports specific UE capabilities and / or when configured / indicated by specific RRC IE / MAC CE / DCI. For example, this option may be applied when the UE reports at least one of 8Tx capability and STxMP SDM capability. For example, this option may be applied when the UE is instructed to use a specific precoder / TPMI.

[0202] [Option 1-3] Both options 1-1 and 1-2 are defined in the specification, and these options may be switched by at least one of UE capability and higher layer signaling.

[0203] The UE may perform different operations or common operations for the case where the DMRS configuration type 1 / 2 of Rel. 15 is configured and the case where the extended DMRS configuration type 1 / 2 of Rel. 18 is configured.

[0204] When a UE uses Rel. 15 DMRS ports, at least one of the antenna port indication tables in embodiments 1-1 and 1-2 may be applied. When a UE uses Rel. 15 DMRS ports, a combination of only Rel. 15 DMRS ports may be indicated. The Rel. 15 DMRS ports may be DMRS ports #0 to #7 for DMRS configuration type 1 or DMRS ports #0 to #11 for DMRS configuration type 2.

[0205] If the UE uses a Rel. 18 DMRS port, the UE may follow embodiment #2.

[0206] <Embodiment #1-1> <DMRS Ports with More Than Four Layers> An example of a table of antenna ports for indicating DMRS ports with more than four layers when the transform precoder is disabled will be described.

[0207] For a codebook-based PUSCH, the UE determines the rank (number of layers) for PUSCH transmission based on the precoding information field of the DCI. For a non-codebook-based PUSCH, the UE determines the rank (number of layers) for PUSCH transmission based on the SRS resource indicator field of the DCI.

[0208] The UE may then determine the table of antenna ports corresponding to the determined rank based on whether the transform precoder is enabled or disabled, the DMRS type of the PUSCH set by higher layer signaling (which may be set by the RRC parameter "dmrs-Type"), and the value of the maximum length of the DMRS (which may be set by the RRC parameter "maxLength").

[0209] In addition, the value of the antenna port field of the DCI may determine the table entry to be referenced (the entry corresponds to a set such as the number of CDM groups without data, the antenna port index of the DMRS, and the number of front-load symbols).

[0210] [When DMRS type=1, max DMRS length=1] When DMRS type=1, max DMRS length=1, transmissions up to rank 4 may be supported. In other words, a UE configured with DMRS type=1 and max DMRS length=1 may not support transmissions greater than rank 4.

[0211] [When DMRS type=1, maximum DMRS length=2] When DMRS type=1, maximum DMRS length=2, transmissions up to rank 8 may be supported.

[0212] 17A-17D are diagrams showing examples of tables of antenna ports to refer to when the transform precoder is disabled, the DMRS type is 1, and the maximum DMRS length is 2.

[0213] 17A is an example of a table of antenna ports corresponding to rank 5. In this example, different sets of DMRS ports (number of antenna ports: 5) are associated with the values ​​of the antenna port field = 0 to 3. Note that the correspondence between values ​​and entry contents is not limited to this. Other examples are similar.

[0214] In Figure 17A, 2+3 layers and 3+2 layers may be supported. Note that only some of the illustrated entries may be supported. For example, only the entries for DMRS ports 0-4 may be supported for the 2+3 layer, and only the entries for DMRS ports 0, 1, 2, 3, and 6 may be supported for the 3+2 layer.

[0215] 17B is an example of a table of antenna ports corresponding to rank 6. In this example, different sets of DMRS ports (6 antenna ports) are associated with the values ​​0 to 2 in the antenna port field.

[0216] In Figure 17B, 4+2 layers, 2+4 layers, and 3+3 layers may be supported, although only certain X, Y combinations (e.g., 3+3) for X+Y layers may be supported.

[0217] 17C is an example of a table of antenna ports corresponding to rank 7. In this example, different sets of DMRS ports (7 antenna ports) are associated with the values ​​0 to 1 in the antenna port field.

[0218] In Figure 17C, 4+3 and 3+4 layers may be supported.

[0219] 17D is an example of a table of antenna ports corresponding to rank 8. In this example, a set of DMRS ports (number of antenna ports: 8) is associated with a value of 0 in the antenna port field.

[0220] In Figure 17D, only 4+4 layers may be supported.

[0221] [When DMRS type = 2, maximum DMRS length = 1] When DMRS type = 2, maximum DMRS length = 1, transmission up to rank 6 may be supported, or only transmission up to rank 4 may be supported, or transmission of rank 6 (e.g., 4+2 layers) may not be supported and only transmission up to rank 5 may be supported.

[0222] 18A and 18B are diagrams showing examples of tables of antenna ports to refer to when the transform precoder is disabled, the DMRS type is 2, and the maximum DMRS length is 1.

[0223] 18A is an example of a table of antenna ports corresponding to rank 5. In this example, a set of DMRS ports (number of antenna ports: 5) is associated with a value of 0 in the antenna port field.

[0224] 18B is an example of a table of antenna ports corresponding to rank 6. In this example, a set of DMRS ports (number of antenna ports: 6) is associated with a value of 0 in the antenna port field.

[0225] [When DMRS type=2, maximum DMRS length=2] When DMRS type=2, maximum DMRS length=2, transmissions up to rank 8 may be supported.

[0226] 19A-19D show examples of tables of antenna ports to reference when the transform precoder is disabled, DMRS type=2, and maximum DMRS length=2.

[0227] 19A is an example of a table of antenna ports corresponding to rank 5. In this example, different sets of DMRS ports (number of antenna ports: 5) are associated with the values ​​0 to 2 in the antenna port field.

[0228] 19B is an example of a table of antenna ports corresponding to rank 6. In this example, different sets of DMRS ports (6 antenna ports) are associated with the values ​​0 to 3 in the antenna port field.

[0229] In Figure 19B, 4+2 layers, 2+4 layers, and 3+3 layers may be supported. Note that only specific X, Y combinations (e.g., 3+3) for X+Y layers may be supported. For example, only the entry corresponding to the value of the antenna port field in Figure 17B = 3 may be supported for 3+3.

[0230] 19C is an example of a table of antenna ports corresponding to rank 7. In this example, different sets of DMRS ports (7 antenna ports) are associated with the values ​​0 to 2 in the antenna port field.

[0231] 19D is an example of a table of antenna ports corresponding to rank 8. In this example, a set of DMRS ports (number of antenna ports: 8) is associated with values ​​0 to 2 in the antenna port field.

[0232] For Figure 19D, only entries corresponding to the 4+4 layer may be supported.

[0233] According to embodiment #1-1, DMRS port indication for a layer number greater than four allows appropriate antenna port specification for a PUSCH using a layer number greater than four when the transform precoder is disabled.

[0234] A DMRS port table that satisfies option 1-1 may be defined.

[0235] According to this embodiment, the UE can transmit the PUSCH using the appropriate DMRS port.

[0236] <Embodiment #2> This embodiment relates to the case where the UE is configured with a Rel. 18 DMRS port (rank is 5 to 8) and DMRS max length (maxLength)=1.

[0237] When the DMRS maximum length (maxLength) is 1, the configuration may follow embodiment #2-1. When Rel. 18 Extended DMRS Configuration Type 1 is configured, the combination of DMRS ports 0-3, and 8 is a combination of three ports from CDM group #0 and two ports from CDM group #1, for a total of five ports. The combination of DMRS ports 0-2, and 8-9 is a combination of four ports from CDM group #0 and one port from CDM group #1, for a total of five ports. The combination of DMRS ports 0, 1, and 8-10 is a combination of four ports from CDM group #0 and one port from CDM group #1, for a total of five ports. The combination of DMRS ports 0, 8-11 is a combination of three ports from CDM group #0 and two ports from CDM group #1, for a total of five ports.

[0238] In embodiment #2-1, the combinations in which the number of ports in CDM group #0 plus the number of ports in CDM group #1 is 5 are 3+2 port, 4+1 port, 4+1 port, and 3+2 port combinations. Since the effect of providing two 4+1 port combinations is small, one of the two combinations may be excluded. Instead of one 4+1 port combination, a 1+4 port combination (e.g., DMRS ports 0, 2, 3, 10, and 11) may be added. In the added combination, any of DMRS ports 1, 8, and 9 may be used instead of DMRS port 0.

[0239] The DMRS port combination in embodiment #2-1 uses more DMRS ports in CDM group #0. A DMRS port combination using more DMRS ports in CDM groups #1 / #2 may be added.

[0240] In embodiment #2-1, the UE may use a combination of a Rel. 15 DMRS port of single-symbol DMRS and a Rel. 18 DMRS port of single-symbol DMRS for PUSCH transmission of rank 5 or higher.

[0241] The UE may be specified the following DMRS port combinations by the antenna ports field for DMRS Type 1: - for rank 8, a combination of port indices 0, 1, 2, 3, 8, 9, 10 and 11; - for rank 7, a combination of seven indices (e.g., 0, 1, 2, 3, 8, 9, 10) from among port indices 0, 1, 2, 3, 8, 9, 10 and 11; - for rank 6, a combination of six indices (e.g., 0, 1, 2, 3, 8, 9) from among port indices 0, 1, 2, 3, 8, 9, 10 and 11; - for rank 5, a combination of five indices (e.g., 0, 1, 2, 3, 8) from among port indices 0, 1, 2, 3, 8, 9, 10 and 11;

[0242] The UE may be specified the following DMRS port combinations by the antenna ports field for DMRS Type 2: - for rank 8, a combination of eight indices (e.g., #0, #1, #2, #3, #4, #5, #12, #13) from among port indices #0, #1, #2, #3, #4, #5, #12, #13, #14, #15, #16, and #17; - for rank 7, a combination of seven indices (e.g., #0, #1, #2, #3, #4, #5, #12) from among port indices #0, #1, #2, #3, #4, #5, #12, #13, #14, #15, #16, and #17; - For rank 6, a combination of six indexes (e.g., #0, #1, #2, #3, #4, #5) from among port indexes #0, #1, #2, #3, #4, #5, #12, #13, #14, #15, #16 and #17; - For rank 5, a combination of five indexes (e.g., #0, #1, #2, #3, #4) from among port indexes #0, #1, #2, #3, #4, #5, #12, #13, #14, #15, #16 and #17.

[0243] An example of a table of antenna ports for PUSCH DMRS port indication (hereinafter also referred to as an antenna port indication table, a DMRS port indication table, a DMRS port table, etc.) is shown below. Note that the UE may determine which antenna port indication table to refer to based on the rank value determined based on the precoding information field / SRI field, the DMRS type, the maximum length of the DMRS, etc.

[0244] The UE may receive DCI for a PUSCH including an antenna port field (antenna port indication), and may control the transmission (mapping, etc.) of DMRS / PUSCH based on the value of the field and the antenna port indication table that it has decided to refer to.

[0245] 20 is a diagram illustrating an example of an antenna port instruction table to be referenced according to embodiment #2-1, when the transform precoder is disabled, the DMRS type is 1, the maximum DMRS length is 1, and the rank is 5. The values ​​(Value) of the antenna port field (Value) = 0 to 3 correspond to {number of Rel. 15 DMRS ports, number of Rel. 18 DMRS ports} = {4, 1}, {3, 2}, {2, 3}, and {1, 4}, respectively.

[0246] A DMRS port combination of one or more DMRS ports from the set of DMRS ports A0 {0, 1, 8, 9} and one or more DMRS ports from the set of DMRS ports B0 {2, 3, 10, 11} may be added to this antenna port indication table or may replace any DMRS port combination in this antenna port indication table. The order of sets A0 and B0 may be swapped.

[0247] For example, a 1+4 layer DMRS port combination including one port from set A0 and four ports from set B0 may be included in this antenna port indication table. For example, a 2+3 layer DMRS port combination including two ports from set A0 and three ports from set B0 may be included in this antenna port indication table. For example, a 3+2 layer DMRS port combination including three ports from set A0 and two ports from set B0 may be included in this antenna port indication table. For example, a 4+1 layer DMRS port combination including four ports from set A0 and one port from set B0 may be included in this antenna port indication table.

[0248] The illustrated table may be referenced by a UE when Rel. 18 DMRS (or Rel. 18 DMRS enabled / Rel. 18 DMRS port enabled) is configured for the UE. Also, multiple entries (rows in the table) indicating the same {number of Rel. 15 DMRS ports, number of Rel. 18 DMRS ports} may be defined, or only some of the illustrated entries may be defined, or a port index combination different from the illustrated port index combination may be defined (the same applies to subsequent drawings related to the antenna port indication table).

[0249] 21 is a diagram illustrating an example of an antenna port instruction table to be referenced according to embodiment #2-1, when the transform precoder is disabled, the DMRS type is 1, the maximum DMRS length is 1, and the rank is 6. The values ​​(Value) of the antenna port field (Value) = 0 to 2 correspond to {number of Rel. 15 DMRS ports, number of Rel. 18 DMRS ports} = {4, 2}, {3, 3}, and {2, 4}, respectively.

[0250] For example, a 2+4 layer DMRS port combination including two ports from set A0 and four ports from set B0 may be included in this antenna port indication table. For example, a 3+3 layer DMRS port combination including three ports from set A0 and three ports from set B0 may be included in this antenna port indication table. For example, a 4+2 layer DMRS port combination including four ports from set A0 and two ports from set B0 may be included in this antenna port indication table.

[0251] 22 is a diagram illustrating an example of an antenna port instruction table to be referenced according to embodiment #2-1, when the transform precoder is disabled, the DMRS type is 1, the maximum DMRS length is 1, and the rank is 7. The values ​​(Value) of the antenna port field (Value) = 0-1 correspond to {number of Rel. 15 DMRS ports} = {4, 3}, {3, 4}, respectively.

[0252] For example, a 3+4 layer DMRS port combination including three ports from set A0 and four ports from set B0 may be included in this antenna port indication table. For example, a 4+3 layer DMRS port combination including four ports from set A0 and three ports from set B0 may be included in this antenna port indication table.

[0253] 23 is a diagram illustrating an example of an antenna port instruction table to be referenced according to embodiment #2-1, when the transform precoder is disabled, the DMRS type is 1, the maximum DMRS length is 1, and the rank is 8. A value of 0 in the antenna port field corresponds to {number of Rel. 15 DMRS ports, number of Rel. 18 DMRS ports}={4, 4}.

[0254] For example, a 4+4 layer DMRS port combination including four ports from set A0 and four ports from set B0 may be included in this antenna port indication table.

[0255] 24 is a diagram illustrating an example of an antenna port instruction table to be referenced according to embodiment #2-1, when the transform precoder is disabled, the DMRS type is 2, the maximum DMRS length is 1, and the rank is 5. The values ​​(Value) of the antenna port field = 0, 1-2, 3-4, 5-7, 7-8, and 9 correspond to {number of Rel. 15 DMRS ports, number of Rel. 18 DMRS ports} = {5, 0}, {4, 1}, {3, 2}, {2, 3}, {1, 4}, and {0, 5}, respectively.

[0256] Note that the DMRS ports corresponding to the illustrated {number of Rel. 15 DMRS ports, number of Rel. 18 DMRS ports} = {5, 0}, {0, 5} use all of CDM groups #0-#2 (as can be seen from FIG. 12 ), so the number of CDM groups is 3.

[0257] Furthermore, the DMRS ports corresponding to the illustrated {number of Rel. 15 DMRS ports, number of Rel. 18 DMRS ports} = {4, 1}, {3, 2}, {2, 3}, {1, 4} use two of CDM groups #0-#2 (as can be seen from FIG. 12 ), so the number of CDM groups is 2 or 3. When the number of CDM groups is 2, the UE can transmit PUSCH in the resource element corresponding to the remaining CDM group in the DMRS symbol (a block of complex-valued symbols (generated by encoding data, etc.) can be mapped to the designated DMRS port (port for PUSCH transmission)), which can be expected to increase communication throughput or reduce the PUSCH error rate based on a reduced coding rate.

[0258] Furthermore, when the number of CDM groups is three, other UEs can use the remaining one CDM group to perform DMRS / PUSCH transmission, which is expected to improve system utilization efficiency.

[0259] In this way, by adopting a table such as that shown in Fig. 24, it is possible to specify different numbers of CDM groups for UEs for the same set of {number of Rel. 15 DMRS ports, number of Rel. 18 DMRS ports} (or the same combination of DMRS ports), thereby enabling flexible control taking into account the traffic of each UE, etc.

[0260] DMRS port combinations from at least two sets, DMRS port set A {0, 1, 12, 13}, DMRS port set B {2, 3, 14, 15}, and DMRS port set C {4, 5, 16, 17}, may be added to the antenna port indication table or may replace any DMRS port combination in the antenna port indication table. The order of sets A, B, and C may be swapped.

[0261] For example, a 1+4 layer DMRS port combination including one port from set A and four ports from set B may be included in the antenna port indication table. For example, a 2+3 layer DMRS port combination including two ports from set A and three ports from set B may be included in the antenna port indication table. For example, a 3+2 layer DMRS port combination including three ports from set A and two ports from set B may be included in the antenna port indication table. For example, a 1+1+3 layer DMRS port combination including one port from set A, one port from set B, and three ports from set C may be included in the antenna port indication table. For example, a 1+2+2 layer DMRS port combination including one port from set A, two ports from set B, and two ports from set C may be included in the antenna port indication table.

[0262] Figure 25 is a diagram showing an example of an antenna port instruction table to be referenced when the transform precoder is disabled, the DMRS type is 2, the maximum DMRS length is 1, and the rank is 6 according to embodiment #2-1.

[0263] For example, a 2+4 layer DMRS port combination including two ports from set A and four ports from set B may be included in the antenna port indication table. For example, a 3+3 layer DMRS port combination including three ports from set A and three ports from set B may be included in the antenna port indication table. For example, a 4+2 layer DMRS port combination including four ports from set A and two ports from set B may be included in the antenna port indication table. For example, a 1+1+4 layer DMRS port combination including one port from set A, one port from set B, and four ports from set C may be included in the antenna port indication table. For example, a 1+2+3 layer DMRS port combination including one port from set A, two ports from set B, and three ports from set C may be included in the antenna port indication table.

[0264] Figure 26 is a diagram showing an example of an antenna port instruction table to be referenced when the transform precoder is disabled, the DMRS type is 2, the maximum DMRS length is 1, and the rank is 7 according to embodiment #2-1.

[0265] The order of sets A, B, and C may be interchanged. For example, a 3+4 layer DMRS port combination including three ports from set A and four ports from set B may be included in the antenna port indication table. For example, a 4+3 layer DMRS port combination including four ports from set A and three ports from set B may be included in the antenna port indication table. For example, a 1+2+4 layer DMRS port combination including one port from set A, two ports from set B, and four ports from set C may be included in the antenna port indication table. For example, a 2+2+3 layer DMRS port combination including two ports from set A, two ports from set B, and three ports from set C may be included in the antenna port indication table.

[0266] Figure 27 is a diagram showing an example of an antenna port instruction table to be referenced when the transform precoder is disabled, the DMRS type is 2, the maximum DMRS length is 1, and the rank is 8 according to embodiment #2-1.

[0267] For example, a 4+4 layer DMRS port combination including four ports from set A and four ports from set B may be included in this antenna port indication table. For example, a 1+3+4 layer DMRS port combination including one port from set A, three ports from set B, and four ports from set C may be included in this antenna port indication table. For example, a 2+2+4 layer DMRS port combination including two ports from set A, two ports from set B, and four ports from set C may be included in this antenna port indication table.

[0268] According to embodiment #2-1, PUSCH transmission of rank 5 or higher can be performed based on single-symbol DMRS, thereby reducing the communication overhead associated with DMRS compared to when it is based on double-symbol DMRS. Also, by using an antenna port indication table with a maximum DMRS length of 1, the size of the antenna port field of DCI can be reduced compared to when the maximum DMRS length is 2 (for example, the tables of Figures 17A-17D), thereby reducing the communication overhead associated with the antenna port field.

[0269] According to this embodiment, the UE can transmit the PUSCH using the appropriate DMRS port.

[0270] <Embodiment #3> This embodiment relates to the case where the UE is configured with a Rel. 18 DMRS port (rank is 5 to 8) and DMRS max length (maxLength)=2.

[0271] 28 is a diagram showing an example of an antenna port instruction table to be referenced when the transform precoder is disabled, the DMRS type is 1, the maximum DMRS length is 2, and the rank is 5. The number and contents of the entries in the antenna port instruction table are not limited to this example.

[0272] 29 is a diagram showing an example of an antenna port instruction table to be referenced when the transform precoder is disabled, the DMRS type is 1, the maximum DMRS length is 2, and the rank is 6. The number and contents of the entries in the antenna port instruction table are not limited to this example.

[0273] 30 is a diagram showing an example of an antenna port instruction table to be referenced when the transform precoder is disabled, the DMRS type is 1, the maximum DMRS length is 2, and the rank is 7. The number and contents of the entries in the antenna port instruction table are not limited to this example.

[0274] 31 is a diagram showing an example of an antenna port instruction table to be referenced when the transform precoder is disabled, the DMRS type is 1, the maximum DMRS length is 2, and the rank is 8. The number and contents of the entries in the antenna port instruction table are not limited to this example.

[0275] In the above antenna port instruction table for DMRS maximum length = 2 and rank = 5 / 6 / 7 / 8, the DMRS port combination corresponding to the number of preceding symbols = 1 may be the same as the DMRS port combination for DMRS maximum length = 1 in embodiment #2-1.

[0276] In the above antenna port indication table for DMRS maximum length=2 and rank=5 / 6 / 7 / 8, the DMRS port combination corresponding to the number of preceding symbols=2 may be as follows.

[0277] For Rel. 18 Extended Type 1 DMRS ports, DMRS port combinations with maxLength=2 and number of front-loaded symbols=1 may be based on the sets X {0, 1, 4, 5, 8, 9, 12, 13} and Y {2, 3, 6, 7, 10, 11, 14, 15} of DMRS ports. The order of sets X and Y may be swapped. In a DMRS port combination, the sum of the number of ports from set X and the number of ports from set Y may be the rank. The DMRS port combination may follow at least one of the following: For rank 5, at least one of the following combinations may be defined: 4 ports from set X and 1 port from set Y; 3 ports from set X and 2 ports from set Y; 2 ports from set X and 3 ports from set Y; and 1 port from set X and 4 ports from set Y. For rank 6, at least one combination of a combination of four ports from set X and two ports from set Y, a combination of three ports from set X and three ports from set Y, or a combination of two ports from set X and four ports from set Y may be defined. For rank 7, at least one combination of a combination of four ports from set X and three ports from set Y, or a combination of three ports from set X and four ports from set Y may be defined. For rank 8, at least one combination of a combination of four ports from set X and four ports from set Y may be defined.

[0278] For Rel. 18 Extended Type 2 DMRS ports, a DMRS port combination with maxLength=2 and number of front-loaded symbols=1 may be based on at least two of the following sets of DMRS ports: X{0, 1, 6, 7, 12, 13, 1, 19}, Y{2, 3, 8, 9, 14, 15, 20, 21}, and Z{4, 5, 10, 11, 16, 17, 22, 23}. The order of sets X, Y, and Z may be interchanged. In a DMRS port combination, the rank may be the sum of the number of ports from set X and the number of ports from set Y, or the rank may be the sum of the number of ports from set X, the number of ports from set Y, and the number of ports from set Z. The DMRS port combination may conform to at least one of the following: For rank 5, at least one combination of a combination of four ports from set X and one port from set Y, a combination of three ports from set X and two ports from set Y, a combination of two ports from set X and three ports from set Y, or a combination of one port from set X and four ports from set Y may be defined. For rank 5, at least one combination of a combination of three ports from set X, one port from set Y, and one port from set Z, or a combination of two ports from set X, two ports from set Y, and one port from set Z may be defined. For rank 6, at least one combination of a combination of four ports from set X and two ports from set Y, a combination of three ports from set X and three ports from set Y, or a combination of two ports from set X and four ports from set Y may be defined. For rank 6, at least one combination of four ports from set X, one port from set Y, and one port from set Z, or three ports from set X, two ports from set Y, and one port from set Z may be defined.For rank 7, at least one combination of four ports from set X and three ports from set Y, or a combination of three ports from set X and four ports from set Y may be defined. For rank 7, at least one combination of four ports from set X, two ports from set Y, and one port from set Z, or a combination of three ports from set X, two ports from set Y, and two ports from set Z, or a combination of three ports from set X, three ports from set Y, and one port from set Z may be defined. For rank 8, at least one combination of four ports from set X and four ports from set Y may be defined. For rank 8, at least one combination of four ports from set X, two ports from set Y, and two ports from set Z, four ports from set X, three ports from set Y, and one port from set Z, or three ports from set X, three ports from set Y, and two ports from set Z may be defined.

[0279] The total number of ports in the DMRS port combination may be equal to the number of ranks.

[0280] According to this embodiment, the UE can transmit PUSCH using an appropriate DMRS port when the DMRS maximum length is 2 and the rank is 5 to 8.

[0281] <Embodiment #4> This embodiment relates to a PUSCH with a DMRS maximum length of 2 and a rank of 5 to 8.

[0282] An antenna port indication table including all of the multiple DMRS port combinations shown in at least one of embodiments #1 to #3 may be defined in the specification. An antenna port indication table including some of the multiple DMRS port combinations shown in at least one of embodiments #1 to #3 may be defined in the specification.

[0283] In the DMRS port combination, the number a of layers (DMRS ports) in CDM group #0 and the number b of layers in CDM group #1 can be expressed in the format of a + b layers. For example, for rank 5, the antenna port indication table may include all DMRS port combinations of 1 + 4 layers, 2 + 3 layers, 3 + 2 layers, and 4 + 1 layers, or may include some of these DMRS port combinations. When a UE transmits using multiple panels (e.g., in the case of partial coherence / non-coherence, Ng = 2 or 4, or STxMP), the transmission / reception power / quality may differ for each panel. It is preferable to be able to flexibly indicate the combination of the number of ports in each CDM group. On the other hand, when a UE transmits using a common panel (e.g., in the case of full coherence, Ng = 1, or not STxMP), the effect of flexibly indicating the combination of the number of ports in each CDM group is considered to be small.

[0284] For a specific rank and a specific DMRS configuration type / DMRS maximum length configuration, the instructable DMRS port combination / antenna port indication table may be switched based on higher layer signaling / UE capability, and the size of the antenna port field may be switched accordingly.

[0285] As shown in the example of Figure 32A, an antenna port instruction table A having higher flexibility in DMRS port combinations, and an antenna port instruction table B having lower flexibility in DMRS port combinations, as shown in the example of Figure 32B, may be defined. Antenna port instruction table A includes DMRS port combinations of 1+4 layers, 2+3 layers, 3+2 layers, and 4+1 layers for rank 5. Antenna port instruction table B includes DMRS port combinations of 4+1 layers for rank 5. The size of the antenna port field when antenna port instruction table A is set may be larger than the size of the antenna port field when antenna port instruction table B is set. For example, the size of the antenna port field when antenna port instruction table A is set may be 3 bits, and the size of the antenna port field when antenna port instruction table B is set may be 2 bits.

[0286] According to this embodiment, the UE can transmit the PUSCH using an appropriate antenna port indication table.

[0287] <Embodiment #5> Figure 33 shows an example of the size of the antenna port field in Rel.

[0288] The number of DMRS port combinations for ranks greater than 4 may be less than the number of DMRS port combinations for ranks equal to or less than 4. In the antenna port indication table for ranks greater than 4, the number of reserved values ​​for the antenna port field may be large, resulting in inefficiency of the antenna port field.

[0289] The number of bits indicating the antenna port field value for a rank greater than 4 may be less than the number of bits indicating the antenna port field value for a rank less than or equal to 4. The antenna port field may follow at least one of several options:

[0290] [Option 5-1] An RRC IE / MAC CE switches between operation using ranks up to 4 (ranks 1 to 4) and operation using ranks greater than 4 (ranks 5 to 8). In this case, the size of the antenna port field for ranks greater than 4 may be smaller than the size of the antenna port field for ranks up to 4.

[0291] [Option 5-2] Operation using ranks of 4 or less (ranks 1 to 4) and operation using ranks greater than 4 (ranks 5 to 8) are switched by DCI (e.g., TPMI / SRI). In this case, the size of the antenna port field for ranks greater than 4 (Figure 34A) may be equal to the size of the antenna port field for ranks of 4 or less (Figure 34B). The number of bits indicating the actual antenna port field value (antenna port indication) may be x bits less than the size (number of bits) of the antenna port field. x may be 1 or may be greater than 1. The x bits may be used for other indications or may be used for indications combined with other DCI fields. The antenna port field value may be indicated by multiple bits excluding the x MSBs or x LSBs of the multiple bits of the antenna port field.

[0292] To support 8Tx (rank greater than 4) / STxMP, DCI overhead may increase. For example, a second TPMI field, a second SRI field, a second TPC command field, etc. may be added. By reducing the number of bits indicating the antenna port field value for ranks greater than 4, the reduced bits can be used for other indications.

[0293] [Variations] In the above, an example has been described in which one antenna port field indicates one or more DMRS ports, but the DCI may include multiple antenna port fields corresponding to multiple antennas / panels / ranks, respectively, and indicate a DMRS port for each of the multiple antennas / panels / ranks.

[0294] According to this embodiment, the overhead of DCI can be reduced.

[0295] <Supplementary Note> In the present disclosure, when a UE / base station uses (referring to / performing processing based on) a table, it does not necessarily mean using the table itself, but may also mean using an array, list, function, etc. that includes information that conforms to the table.

[0296] [Notification of Information to UE] In the above-described embodiments, any information may be notified to the UE (from a network (NW) (e.g., a base station (BS))) (in other words, reception of any information from the BS by the UE) using physical layer signaling (e.g., DCI), higher layer signaling (e.g., RRC signaling, MAC CE), a specific signal / channel (e.g., PDCCH, PDSCH, reference signal), or a combination thereof.

[0297] When the notification is performed by a MAC CE, the MAC CE may be identified by including a new Logical Channel ID (LCID) in the MAC subheader, which is not defined in existing standards.

[0298] When the notification is made by DCI, the notification may be made by a specific field of the DCI, a Radio Network Temporary Identifier (RNTI) used to scramble Cyclic Redundancy Check (CRC) bits assigned to the DCI, the format of the DCI, etc.

[0299] Furthermore, notification of any information to the UE in the above embodiments may be performed periodically, semi-persistently, or aperiodically.

[0300] [Notification of Information from UE] In the above-described embodiments, notification of any information from the UE (to the NW) (in other words, transmission / report of any information from the UE to the BS) may be performed using physical layer signaling (e.g., UCI), higher layer signaling (e.g., RRC signaling, MAC CE), a specific signal / channel (e.g., PUCCH, PUSCH, PRACH, reference signal), or a combination thereof.

[0301] When the notification is performed by a MAC CE, the MAC CE may be identified by including a new LCID, which is not defined in existing standards, in the MAC subheader.

[0302] If the notification is made by UCI, the notification may be transmitted using PUCCH or PUSCH.

[0303] Furthermore, any information in the above-described embodiments may be notified from the UE periodically, semi-persistently, or aperiodically.

[0304] [Application of Each Embodiment] At least one of the above-described embodiments may be applied when a specific condition is met. The specific condition may be defined in a standard or may be notified to a UE / BS using higher layer signaling / physical layer signaling.

[0305] At least one of the above-described embodiments may be applied only to UEs that have reported or support a particular UE capability.

[0306] The specific UE capabilities may indicate at least one of the following: Supporting specific processing / operations / control / information for at least one of the above embodiments, Supporting dynamic switching of Rel. 15 DMRS ports (tables) and Rel. 18 DMRS ports (tables), Supporting PUSCH transmission with a number of layers greater than four, Supporting STxMP, Supporting SDM for single DCI-based STxMP PUSCH (STxMP SDM) scheme P, Supporting SFN-based transmission scheme for STxMP PUSCH transmission in a single DCI-based multi-TRP system, Supporting 8Tx.

[0307] Furthermore, the above-mentioned specific UE capability may be a capability that is applied across all frequencies (commonly regardless of frequency), or may be a capability for each frequency (e.g., one or a combination of a cell, a band, a band combination, a BWP, a component carrier, etc.), or may be a capability for each frequency range (e.g., Frequency Range 1 (FR1), FR2, FR3, FR4, FR5, FR2-1, FR2-2), or may be a capability for each subcarrier spacing (SubCarrier Spacing (SCS)), or may be a capability for each Feature Set (FS) or Feature Set Per Component-carrier (FSPC).

[0308] Furthermore, the specific UE capability may be a capability that is applied to all duplexing methods (commonly regardless of the duplexing method), or may be a capability for each duplexing method (e.g., Time Division Duplex (TDD) or Frequency Division Duplex (FDD)).

[0309] Furthermore, at least one of the above-described embodiments may be applied when a UE configures / activates / triggers specific information related to the above-described embodiments (or performs the operations of the above-described embodiments) through higher layer signaling / physical layer signaling. For example, the specific information may be information indicating enabling dynamic switching of DMRS ports, information indicating enabling dynamic switching of DMRS ports of a specific release (e.g., Rel. 15 DMRS ports and Rel. 18 DMRS ports), information indicating enabling dynamic switching of an antenna port indication table, information indicating enabling an increased number of DMRS ports, configuration information for DMRS type 1 (or 2) / single-symbol DMRS / max DMRS length=1, any RRC parameter for a specific release (e.g., Rel. 18 / 19), etc.

[0310] If the UE does not support at least one of the specific UE capabilities or is not configured with the specific information, the UE may apply, for example, Rel. 15 / 16 behavior.

[0311] (Supplementary Notes) The following inventions are supplemented with respect to one embodiment of the present disclosure. [Supplementary Note 1] A terminal comprising: a receiver unit that receives downlink control information that schedules an uplink shared channel with multiple repetitions using the same frequency resource and the same time resource; and a controller that determines a combination of multiple demodulation reference signal (DMRS) ports based on the downlink control information. [Supplementary Note 2] The terminal according to Supplementary Note 1, wherein the combination includes multiple ports from multiple code division multiplexing (CDM) groups. [Supplementary Note 3] The terminal according to Supplementary Note 1 or Supplementary Note 2, wherein the combination depends on an antenna coherence assumption. [Supplementary Note 4] The terminal according to any one of Supplementary Notes 1 to 3, wherein the combination is associated with multiple panels.

[0312] (Supplementary Notes) The following inventions are supplemented with respect to one embodiment of the present disclosure. [Supplementary Note 1] A terminal having: a receiver that receives downlink control information that schedules uplink shared channels of more than four ranks; and a controller that determines a combination of multiple demodulation reference signal ports based on the downlink control information. [Supplementary Note 2] The terminal according to Supplementary Note 1, wherein the combination includes multiple ports from multiple code division multiplexing (CDM) groups. [Supplementary Note 3] The terminal according to Supplementary Note 1 or Supplementary Note 2, wherein the combination depends on an antenna coherence assumption. [Supplementary Note 4] The terminal according to any one of Supplementary Notes 1 to 3, wherein the combination is associated with multiple panels.

[0313] (Wireless Communication System) The configuration of a wireless communication system according to an embodiment of the present disclosure will be described below. In this wireless communication system, communication is performed using any one of the wireless communication methods according to the above embodiments of the present disclosure or a combination thereof.

[0314] 35 is a diagram showing an example of a schematic configuration of a wireless communication system according to an embodiment. The wireless communication system 1 (which may be simply referred to as system 1) may be a system that realizes communication using Long Term Evolution (LTE) specified by the Third Generation Partnership Project (3GPP), 5th generation mobile communication system New Radio (5G NR), or the like.

[0315] The wireless communication system 1 may also support dual connectivity between multiple Radio Access Technologies (RATs) (Multi-RAT Dual Connectivity (MR-DC)). MR-DC may include dual connectivity between LTE (Evolved Universal Terrestrial Radio Access (E-UTRA)) and NR (E-UTRA-NR Dual Connectivity (EN-DC)), dual connectivity between NR and LTE (NR-E-UTRA Dual Connectivity (NE-DC)), etc.

[0316] In EN-DC, the LTE (E-UTRA) base station (eNB) is the master node (Master Node (MN)), and the NR base station (gNB) is the secondary node (Secondary Node (SN)). In NE-DC, the NR base station (gNB) is the MN, and the LTE (E-UTRA) base station (eNB) is the SN.

[0317] The wireless communication system 1 may support dual connectivity between multiple base stations within the same RAT (for example, dual connectivity in which both the MN and SN are NR base stations (gNBs) (NR-NR Dual Connectivity (NN-DC))).

[0318] The wireless communication system 1 may include a base station 11 that forms a macrocell C1 with a relatively wide coverage, and base stations 12 (12a-12c) that are located within the macrocell C1 and form small cells C2 that are smaller than the macrocell C1. A user terminal 20 may be located within at least one of the cells. The locations and numbers of the cells and user terminals 20 are not limited to the embodiment shown in the figure. Hereinafter, when there is no need to distinguish between the base stations 11 and 12, they will be collectively referred to as base station 10.

[0319] The user terminal 20 may be connected to at least one of the multiple base stations 10. The user terminal 20 may utilize at least one of carrier aggregation (CA) using multiple component carriers (CCs) and dual connectivity (DC).

[0320] Each CC may be included in at least one of a first frequency band (Frequency Range 1 (FR1)) and a second frequency band (Frequency Range 2 (FR2)). The macro cell C1 may be included in FR1, and the small cell C2 may be included in FR2. For example, FR1 may be a frequency band of 6 GHz or less (sub-6 GHz), and FR2 may be a frequency band higher than 24 GHz (above-24 GHz). Note that the frequency bands and definitions of FR1 and FR2 are not limited to these, and for example, FR1 may correspond to a higher frequency band than FR2.

[0321] Furthermore, the user terminal 20 may perform communication using at least one of time division duplex (TDD) and frequency division duplex (FDD) in each CC.

[0322] The multiple base stations 10 may be connected by wire (e.g., optical fiber compliant with the Common Public Radio Interface (CPRI), an X2 interface, etc.) or wirelessly (e.g., NR communication). For example, when NR communication is used as a backhaul between the base stations 11 and 12, the base station 11 corresponding to the upper station may be called an Integrated Access Backhaul (IAB) donor, and the base station 12 corresponding to the relay station (relay) may be called an IAB node.

[0323] The base station 10 may be connected to the core network 30 directly or via another base station 10. The core network 30 may include, for example, at least one of an Evolved Packet Core (EPC), a 5G Core Network (5GCN), a Next Generation Core (NGC), and the like.

[0324] The core network 30 may include network functions (Network Functions (NF)) such as a User Plane Function (UPF), an Access and Mobility management Function (AMF), a Session Management Function (SMF), a Unified Data Management (UDM), an Application Function (AF), a Data Network (DN), a Location Management Function (LMF), and Operation, Administration and Maintenance (Management) (OAM). A single network node may provide multiple functions. Communication with an external network (e.g., the Internet) may also be performed via the DN.

[0325] The user terminal 20 may be a terminal that supports at least one of communication methods such as LTE, LTE-A, and 5G.

[0326] An Orthogonal Frequency Division Multiplexing (OFDM)-based radio access scheme may be used in the wireless communication system 1. For example, Cyclic Prefix OFDM (CP-OFDM), Discrete Fourier Transform Spread OFDM (DFT-s-OFDM), Orthogonal Frequency Division Multiple Access (OFDMA), Single Carrier Frequency Division Multiple Access (SC-FDMA), or the like may be used in at least one of the downlink (DL) and uplink (UL).

[0327] The radio access scheme may also be called a waveform. Note that in the wireless communication system 1, other radio access schemes (e.g., other single-carrier transmission schemes, other multi-carrier transmission schemes) may be used as the UL and DL radio access schemes.

[0328] In the wireless communication system 1, a downlink shared channel (Physical Downlink Shared Channel (PDSCH)) shared by each user terminal 20, a broadcast channel (Physical Broadcast Channel (PBCH)), a downlink control channel (Physical Downlink Control Channel (PDCCH)), etc. may be used as the downlink channel.

[0329] Furthermore, in the wireless communication system 1, an uplink shared channel (Physical Uplink Shared Channel (PUSCH)) shared by each user terminal 20, an uplink control channel (Physical Uplink Control Channel (PUCCH)), a random access channel (Physical Random Access Channel (PRACH)), or the like may be used as an uplink channel.

[0330] The PDSCH transmits user data, higher layer control information, a System Information Block (SIB), etc. The PUSCH may transmit user data, higher layer control information, etc. Furthermore, the PBCH may transmit a Master Information Block (MIB).

[0331] Lower layer control information may be transmitted by the PDCCH. The lower layer control information may include, for example, Downlink Control Information (DCI) including scheduling information for at least one of the PDSCH and the PUSCH.

[0332] Note that the DCI for scheduling the PDSCH may be referred to as a DL assignment, a DL DCI, etc., and the DCI for scheduling the PUSCH may be referred to as a UL grant, a UL DCI, etc. Note that the PDSCH may be replaced with DL data, and the PUSCH may be replaced with UL data.

[0333] A control resource set (CORESET) and a search space may be used to detect the PDCCH. The CORESET corresponds to resources for searching for DCI. The search space corresponds to a search region and a search method for PDCCH candidates. One CORESET may be associated with one or more search spaces. The UE may monitor the CORESET associated with a certain search space based on the search space configuration.

[0334] One search space may correspond to PDCCH candidates corresponding to one or more aggregation levels. One or more search spaces may be referred to as a search space set. Note that the terms "search space," "search space set," "search space configuration," "search space set configuration," "CORESET," "CORESET configuration," and the like in the present disclosure may be read interchangeably.

[0335] The PUCCH may transmit uplink control information (UCI) including at least one of channel state information (CSI), delivery confirmation information (which may be called, for example, Hybrid Automatic Repeat reQuest ACKnowledgement (HARQ-ACK), ACK / NACK, etc.), and scheduling request (SR). The PRACH may transmit a random access preamble for establishing a connection with a cell.

[0336] In the present disclosure, downlink, uplink, etc. may be expressed without adding "link." Also, various channels may be expressed without adding "Physical" to the beginning.

[0337] In the wireless communication system 1, a synchronization signal (SS), a downlink reference signal (DL-RS), etc. may be transmitted. In the wireless communication system 1, as the DL-RS, a cell-specific reference signal (CRS), a channel state information reference signal (CSI-RS), a demodulation reference signal (DMRS), a positioning reference signal (PRS), a phase tracking reference signal (PTRS), etc. may be transmitted.

[0338] The synchronization signal may be, for example, at least one of a Primary Synchronization Signal (PSS) and a Secondary Synchronization Signal (SSS). A signal block including an SS (PSS, SSS) and a PBCH (and a DMRS for the PBCH) may be referred to as an SS / PBCH block, an SS Block (SSB), or the like. Note that the SS, SSB, and the like may also be referred to as a reference signal.

[0339] Furthermore, in the wireless communication system 1, a sounding reference signal (SRS), a demodulation reference signal (DMRS), or the like may be transmitted as an uplink reference signal (UL-RS). Note that the DMRS may also be called a user equipment-specific reference signal (UE-specific reference signal).

[0340] (Base Station) Fig. 36 is a diagram showing an example of the configuration of a base station according to an embodiment. The base station 10 includes a control unit 110, a transceiver unit 120, a transceiver antenna 130, and a transmission line interface 140. Note that the base station may include one or more of each of the control unit 110, the transceiver unit 120, the transceiver antenna 130, and the transmission line interface 140.

[0341] In this example, the functional blocks of the characteristic parts of the present embodiment are mainly shown, and it may be assumed that the base station 10 also has other functional blocks necessary for wireless communication. Some of the processing of each unit described below may be omitted.

[0342] The control unit 110 performs overall control of the base station 10. The control unit 110 can be configured from a controller, a control circuit, and the like that are explained based on common understanding in the technical field to which the present disclosure relates.

[0343] The control unit 110 may control signal generation, scheduling (e.g., resource allocation, mapping), etc. The control unit 110 may control transmission and reception using the transceiver unit 120, the transceiver antenna 130, and the transmission path interface 140, measurement, etc. The control unit 110 may generate data, control information, sequences, etc. to be transmitted as signals, and transfer them to the transceiver unit 120. The control unit 110 may perform call processing (setting up, releasing, etc.) of communication channels, status management of the base station 10, management of radio resources, etc.

[0344] The transceiver unit 120 may include a baseband unit 121, a radio frequency (RF) unit 122, and a measurement unit 123. The baseband unit 121 may include a transmission processing unit 1211 and a reception processing unit 1212. The transceiver unit 120 may be configured with a transmitter / receiver, an RF circuit, a baseband circuit, a filter, a phase shifter, a measurement circuit, a transceiver circuit, etc., which are described based on common understanding in the technical field related to the present disclosure.

[0345] The transmitting / receiving unit 120 may be configured as an integrated transmitting / receiving unit, or may be configured from a transmitting unit and a receiving unit. The transmitting unit may be configured from a transmission processing unit 1211 and an RF unit 122. The receiving unit may be configured from a reception processing unit 1212, the RF unit 122, and a measurement unit 123.

[0346] The transmitting and receiving antenna 130 can be configured from an antenna described based on common understanding in the technical field to which the present disclosure relates, such as an array antenna.

[0347] The transceiver 120 may transmit the above-mentioned downlink channel, synchronization signal, downlink reference signal, etc. The transceiver 120 may receive the above-mentioned uplink channel, uplink reference signal, etc.

[0348] The transceiver 120 may form at least one of the transmit beam and the receive beam using digital beamforming (e.g., precoding), analog beamforming (e.g., phase rotation), or the like.

[0349] The transmitter / receiver unit 120 (transmission processing unit 1211) may perform Packet Data Convergence Protocol (PDCP) layer processing, Radio Link Control (RLC) layer processing (e.g., RLC retransmission control), Medium Access Control (MAC) layer processing (e.g., HARQ retransmission control), etc. on data, control information, etc. obtained from the control unit 110, and generate a bit string to be transmitted.

[0350] The transmitter / receiver unit 120 (transmission processing unit 1211) may perform transmission processing such as channel coding (which may include error correction coding), modulation, mapping, filtering, Discrete Fourier Transform (DFT) processing (if necessary), Inverse Fast Fourier Transform (IFFT) processing, precoding, and digital-to-analog conversion on the bit string to be transmitted, and output a baseband signal.

[0351] The transceiver unit 120 (RF unit 122) may perform modulation, filtering, amplification, etc. on the baseband signal to a radio frequency band, and transmit the radio frequency band signal via the transceiver antenna 130.

[0352] On the other hand, the transceiver unit 120 (RF unit 122) may perform amplification, filtering, demodulation to a baseband signal, etc. on the radio frequency band signal received by the transceiver antenna 130.

[0353] The transceiver 120 (reception processing unit 1212) may apply reception processing such as analog-to-digital conversion, Fast Fourier Transform (FFT) processing, Inverse Discrete Fourier Transform (IDFT) processing (if necessary), filtering, demapping, demodulation, decoding (which may include error correction decoding), MAC layer processing, RLC layer processing, and PDCP layer processing to the acquired baseband signal, thereby acquiring user data, etc.

[0354] The transceiver 120 (measurement unit 123) may perform measurements on the received signal. For example, the measurement unit 123 may perform Radio Resource Management (RRM) measurements, Channel State Information (CSI) measurements, etc. based on the received signal. The measurement unit 123 may measure received power (e.g., Reference Signal Received Power (RSRP)), received quality (e.g., Reference Signal Received Quality (RSRQ), Signal to Interference plus Noise Ratio (SINR), Signal to Noise Ratio (SNR)), signal strength (e.g., Received Signal Strength Indicator (RSSI)), propagation path information (e.g., CSI), etc. The measurement results may be output to the control unit 110.

[0355] The transmission path interface 140 may transmit and receive signals (backhaul signaling) between devices included in the core network 30 (e.g., network nodes that provide NF), other base stations 10, etc., and may acquire and transmit user data (user plane data), control plane data, etc. for the user terminal 20.

[0356] The transmitting section and receiving section of the base station 10 in the present disclosure may be configured by at least one of the transmitting / receiving section 120, the transmitting / receiving antenna 130, and the transmission path interface 140.

[0357] The controller 110 may determine a combination of multiple demodulation reference signal (DMRS) ports for an uplink shared channel with multiple repetitions using the same frequency resource and the same time resource. The transceiver 120 may transmit downlink control information scheduling the uplink shared channel.

[0358] The controller 110 may determine a combination of multiple demodulation reference signal (DMRS) ports for an uplink shared channel with a rank greater than 4. The transceiver 120 may transmit downlink control information that schedules the uplink shared channel.

[0359] (User terminal) Fig. 37 is a diagram showing an example of the configuration of a user terminal according to one embodiment. The user terminal 20 includes a control unit 210, a transceiver unit 220, and a transceiver antenna 230. Note that the user terminal 20 may include one or more of each of the control unit 210, the transceiver unit 220, and the transceiver antenna 230.

[0360] In this example, the functional blocks of the characteristic parts of the present embodiment are mainly shown, and it may be assumed that the user terminal 20 also has other functional blocks necessary for wireless communication. Some of the processing of each unit described below may be omitted.

[0361] The control unit 210 performs overall control of the user terminal 20. The control unit 210 can be configured from a controller, a control circuit, etc., which are described based on common understanding in the technical field to which the present disclosure relates.

[0362] The control unit 210 may control signal generation, mapping, etc. The control unit 210 may control transmission and reception, measurement, etc. using the transceiver unit 220 and the transceiver antenna 230. The control unit 210 may generate data, control information, sequences, etc. to be transmitted as signals and transfer them to the transceiver unit 220.

[0363] The transceiver unit 220 may include a baseband unit 221, an RF unit 222, and a measurement unit 223. The baseband unit 221 may include a transmission processing unit 2211 and a reception processing unit 2212. The transceiver unit 220 may be configured with a transmitter / receiver, an RF circuit, a baseband circuit, a filter, a phase shifter, a measurement circuit, a transceiver circuit, etc., which are described based on common understanding in the technical field related to the present disclosure.

[0364] The transmitting / receiving unit 220 may be configured as an integrated transmitting / receiving unit, or may be composed of a transmitting unit and a receiving unit. The transmitting unit may be composed of a transmission processing unit 2211 and an RF unit 222. The receiving unit may be composed of a reception processing unit 2212, an RF unit 222, and a measurement unit 223.

[0365] The transmitting / receiving antenna 230 can be configured from an antenna described based on common understanding in the technical field to which the present disclosure relates, such as an array antenna.

[0366] The transceiver 220 may receive the above-mentioned downlink channel, synchronization signal, downlink reference signal, etc. The transceiver 220 may transmit the above-mentioned uplink channel, uplink reference signal, etc.

[0367] The transceiver unit 220 may form at least one of the transmit beam and the receive beam using digital beamforming (e.g., precoding), analog beamforming (e.g., phase rotation), or the like.

[0368] The transceiver unit 220 (transmission processing unit 2211) may perform PDCP layer processing, RLC layer processing (e.g., RLC retransmission control), MAC layer processing (e.g., HARQ retransmission control), etc. on data, control information, etc. obtained from the control unit 210, and generate a bit string to be transmitted.

[0369] The transmitter / receiver unit 220 (transmission processing unit 2211) may perform transmission processing such as channel coding (which may include error correction coding), modulation, mapping, filtering, DFT processing (if necessary), IFFT processing, precoding, and digital-to-analog conversion on the bit string to be transmitted, and output a baseband signal.

[0370] Whether or not to apply DFT processing may be based on the setting of transform precoding. When transform precoding is enabled for a certain channel (e.g., PUSCH), the transceiver unit 220 (transmission processing unit 2211) may perform DFT processing as the transmission processing to transmit the channel using a DFT-s-OFDM waveform, and if not, it may not be necessary to perform DFT processing as the transmission processing.

[0371] The transceiver unit 220 (RF unit 222) may perform modulation, filtering, amplification, etc. on the baseband signal to a radio frequency band, and transmit the radio frequency band signal via the transceiver antenna 230.

[0372] On the other hand, the transceiver unit 220 (RF unit 222) may perform amplification, filtering, demodulation to a baseband signal, etc. on the radio frequency band signal received by the transceiver antenna 230.

[0373] The transceiver unit 220 (reception processing unit 2212) may apply reception processing such as analog-to-digital conversion, FFT processing, IDFT processing (if necessary), filtering, demapping, demodulation, decoding (which may include error correction decoding), MAC layer processing, RLC layer processing, and PDCP layer processing to the acquired baseband signal, and acquire user data, etc.

[0374] The transceiver 220 (measurement unit 223) may perform measurements on the received signal. For example, the measurement unit 223 may perform RRM measurements, CSI measurements, etc. based on the received signal. The measurement unit 223 may measure received power (e.g., RSRP), received quality (e.g., RSRQ, SINR, SNR), signal strength (e.g., RSSI), propagation path information (e.g., CSI), etc. The measurement results may be output to the control unit 210.

[0375] The transmitting unit and receiving unit of the user terminal 20 in the present disclosure may be configured by at least one of the transmitting / receiving unit 220 and the transmitting / receiving antenna 230.

[0376] The transceiver 220 may receive downlink control information that schedules an uplink shared channel with multiple repetitions using the same frequency resource and the same time resource. The controller 210 may determine a combination of multiple demodulation reference signal (DMRS) ports based on the downlink control information.

[0377] The combination may include multiple ports from multiple code division multiplexing (CDM) groups.

[0378] The combination may depend on antenna coherence assumptions.

[0379] The combination may be associated with multiple panels.

[0380] The transceiver 220 may receive downlink control information that schedules uplink shared channels with a rank greater than 4. The controller 210 may determine a combination of multiple demodulation reference signal (DMRS) ports based on the downlink control information.

[0381] The combination may include multiple ports from multiple code division multiplexing (CDM) groups.

[0382] The combination may depend on antenna coherence assumptions.

[0383] The combination may be associated with multiple panels.

[0384] (Hardware Configuration) Note that the block diagrams used to explain the above embodiments show functional blocks. These functional blocks (components) are realized by any combination of at least one of hardware and software. Furthermore, the method for realizing each functional block is not particularly limited. That is, each functional block may be realized using a single device that is physically or logically coupled, or may be realized using two or more physically or logically separated devices that are directly or indirectly connected (for example, using wires, wirelessly, etc.) and these multiple devices. The functional block may be realized by combining software with the single device or the multiple devices.

[0385] Here, the functions include, but are not limited to, judgment, determination, judgment, calculation, computation, processing, derivation, investigation, search, confirmation, reception, transmission, output, access, resolution, selection, election, establishment, comparison, assumption, expectation, deeming, broadcasting, notifying, communicating, forwarding, configuring, reconfiguring, allocating, mapping, and assignment. For example, a functional block (component) that performs transmission may be called a transmitting unit, transmitter, etc. As described above, the implementation method of each is not particularly limited.

[0386] For example, a base station, a user terminal, etc. according to an embodiment of the present disclosure may function as a computer that performs processing of the wireless communication method of the present disclosure. Figure 38 is a diagram illustrating an example of the hardware configuration of a base station and a user terminal according to an embodiment. The above-described base station 10 and user terminal 20 may be physically configured as a computer device including a processor 1001, a memory 1002, a storage 1003, a communication device 1004, an input device 1005, an output device 1006, a bus 1007, etc.

[0387] In the present disclosure, the terms apparatus, circuit, device, section, unit, etc. may be used interchangeably. The hardware configurations of the base station 10 and the user terminal 20 may be configured to include one or more of the devices shown in the drawings, or may be configured to exclude some of the devices.

[0388] For example, although only one processor 1001 is shown, there may be multiple processors. Furthermore, processing may be performed by one processor, or processing may be performed by two or more processors simultaneously, serially, or in other ways. Furthermore, processor 1001 may be implemented by one or more chips.

[0389] Each function in the base station 10 and the user terminal 20 is realized, for example, by loading specified software (programs) onto hardware such as a processor 1001 and a memory 1002, causing the processor 1001 to perform calculations, control communication via the communication device 1004, and control at least one of reading and writing data in the memory 1002 and the storage 1003.

[0390] The processor 1001, for example, runs an operating system to control the entire computer. The processor 1001 may be configured as a central processing unit (CPU) including an interface with peripheral devices, a control device, an arithmetic unit, a register, etc. For example, at least a part of the above-mentioned control unit 110 (210), transceiver unit 120 (220), etc. may be realized by the processor 1001.

[0391] The processor 1001 also reads programs (program codes), software modules, data, etc. from at least one of the storage 1003 and the communication device 1004 into the memory 1002 and executes various processes in accordance with these. The programs used are those that cause a computer to execute at least some of the operations described in the above-described embodiments. For example, the control unit 110 (210) may be implemented by a control program stored in the memory 1002 and running on the processor 1001, and the other functional blocks may be implemented in a similar manner.

[0392] The memory 1002 is a computer-readable recording medium and may be configured by at least one of, for example, Read Only Memory (ROM), Erasable Programmable ROM (EPROM), Electrically EEPROM (EEPROM), Random Access Memory (RAM), or other suitable storage medium. The memory 1002 may also be referred to as a register, cache, main memory, etc. The memory 1002 may store executable programs (program codes), software modules, etc. for implementing a wireless communication method according to an embodiment of the present disclosure.

[0393] Storage 1003 is a computer-readable recording medium and may be composed of at least one of, for example, a flexible disk, a floppy disk, a magneto-optical disk (e.g., a compact disc (e.g., a Compact Disc ROM (CD-ROM)), a digital versatile disc, a Blu-ray disc), a removable disk, a hard disk drive, a smart card, a flash memory device (e.g., a card, a stick, a key drive), a magnetic stripe, a database, a server, or other suitable storage medium. Storage 1003 may also be referred to as an auxiliary storage device.

[0394] The communication device 1004 is hardware (transmission / reception device) for communicating between computers via at least one of a wired network and a wireless network, and is also referred to as, for example, a network device, a network controller, a network card, or a communication module. The communication device 1004 may be configured to include a high-frequency switch, a duplexer, a filter, a frequency synthesizer, etc. to realize at least one of frequency division duplex (FDD) and time division duplex (TDD). For example, the above-mentioned transmission / reception unit 120 (220), transmission / reception antenna 130 (230), etc. may be realized by the communication device 1004. The transmission / reception unit 120 (220) may be implemented as a transmission unit 120a (220a) and a reception unit 120b (220b) that are physically or logically separated.

[0395] The input device 1005 is an input device (e.g., a keyboard, a mouse, a microphone, a switch, a button, a sensor, etc.) that accepts input from the outside. The output device 1006 is an output device (e.g., a display, a speaker, a light emitting diode (LED) lamp, etc.) that outputs to the outside. Note that the input device 1005 and the output device 1006 may be integrated into one device (e.g., a touch panel).

[0396] Furthermore, each device, such as the processor 1001 and the memory 1002, is connected by a bus 1007 for communicating information. The bus 1007 may be configured using a single bus, or may be configured using different buses between each device.

[0397] Furthermore, the base station 10 and the user terminal 20 may be configured to include hardware such as a microprocessor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a programmable logic device (PLD), or a field programmable gate array (FPGA), and some or all of the functional blocks may be realized using this hardware. For example, the processor 1001 may be implemented using at least one of these pieces of hardware.

[0398] (Modifications) Note that terms described in the present disclosure and terms necessary for understanding the present disclosure may be replaced with terms having the same or similar meanings. For example, a channel, a symbol, and a signal (signal or signaling) may be interchangeable. A signal may also be a message. A reference signal may be abbreviated as RS, and may also be called a pilot, pilot signal, etc. depending on the applicable standard. A component carrier (CC) may also be called a cell, frequency carrier, carrier frequency, etc.

[0399] A radio frame may be composed of one or more periods (frames) in the time domain. Each of the one or more periods (frames) constituting a radio frame may be called a subframe. Furthermore, a subframe may be composed of one or more slots in the time domain. A subframe may have a fixed time length (e.g., 1 ms) that is independent of numerology.

[0400] Here, the numerology may be a communication parameter applied to at least one of transmission and reception of a signal or channel, and may indicate at least one of, for example, Subcarrier Spacing (SCS), bandwidth, symbol length, cyclic prefix length, Transmission Time Interval (TTI), number of symbols per TTI, radio frame structure, specific filtering performed by a transceiver in the frequency domain, and specific windowing performed by a transceiver in the time domain.

[0401] A slot may be composed of one or more symbols (such as an Orthogonal Frequency Division Multiplexing (OFDM) symbol or a Single Carrier Frequency Division Multiple Access (SC-FDMA) symbol) in the time domain. A slot may also be a time unit based on numerology.

[0402] A slot may include multiple minislots. Each minislot may consist of one or multiple symbols in the time domain. A minislot may also be called a subslot. A minislot may consist of fewer symbols than a slot. A PDSCH (or PUSCH) transmitted in a time unit larger than a minislot may be called PDSCH (PUSCH) mapping type A. A PDSCH (or PUSCH) transmitted using a minislot may be called PDSCH (PUSCH) mapping type B.

[0403] A radio frame, a subframe, a slot, a minislot, and a symbol all represent time units for transmitting signals. The radio frame, the subframe, the slot, the minislot, and the symbol may be referred to by other names corresponding to the radio frame, the subframe, the slot, the minislot, and the symbol. Note that the time units such as a frame, a subframe, a slot, a minislot, and a symbol in the present disclosure may be interchangeable.

[0404] For example, one subframe may be referred to as a TTI, or multiple consecutive subframes may be referred to as a TTI, or one slot or one minislot may be referred to as a TTI. That is, at least one of the subframe and the TTI may be a subframe (1 ms) in existing LTE, a period shorter than 1 ms (for example, 1-13 symbols), or a period longer than 1 ms. Note that the unit representing the TTI may be called a slot, minislot, etc. instead of a subframe.

[0405] Here, TTI refers to, for example, the smallest time unit for scheduling in wireless communication. For example, in an LTE system, a base station performs scheduling to allocate radio resources (such as frequency bandwidth and transmission power that can be used by each user terminal) to each user terminal in TTI units. Note that the definition of TTI is not limited to this.

[0406] The TTI may be a transmission time unit for a channel-encoded data packet (transport block), a code block, a code word, etc., or may be a processing unit for scheduling, link adaptation, etc. When a TTI is given, the time interval (e.g., the number of symbols) to which a transport block, a code block, a code word, etc. is actually mapped may be shorter than the TTI.

[0407] When one slot or one minislot is called a TTI, one or more TTIs (i.e., one or more slots or one or more minislots) may be the minimum time unit for scheduling. Also, the number of slots (minislots) constituting the minimum time unit for scheduling may be controlled.

[0408] A TTI having a time length of 1 ms may be called a regular TTI (TTI in 3GPP Rel. 8-12), normal TTI, long TTI, regular subframe, normal subframe, long subframe, slot, etc. A TTI shorter than a regular TTI may be called a shortened TTI, short TTI, partial or fractional TTI, shortened subframe, short subframe, minislot, subslot, slot, etc.

[0409] In addition, a long TTI (e.g., a normal TTI, a subframe, etc.) may be interpreted as a TTI having a time length of more than 1 ms, and a short TTI (e.g., a shortened TTI, etc.) may be interpreted as a TTI having a TTI length shorter than the TTI length of a long TTI and greater than or equal to 1 ms.

[0410] A resource block (RB) is a resource allocation unit in the time domain and the frequency domain, and may include one or more consecutive subcarriers in the frequency domain. The number of subcarriers included in an RB may be the same regardless of numerology, for example, 12. The number of subcarriers included in an RB may be determined based on numerology.

[0411] In addition, an RB may include one or more symbols in the time domain and may have a length of one slot, one minislot, one subframe, or one TTI, each of which may be composed of one or more resource blocks.

[0412] In addition, one or more RBs may be referred to as a physical resource block (PRB), a sub-carrier group (SCG), a resource element group (REG), a PRB pair, an RB pair, etc.

[0413] Furthermore, a resource block may be composed of one or more resource elements (REs). For example, one RE may be a radio resource region of one subcarrier and one symbol.

[0414] A Bandwidth Part (BWP), which may also be referred to as a partial bandwidth, may represent a subset of contiguous common resource blocks (RBs) for a given numerology on a given carrier, where the common RBs may be identified by their index relative to a Common Reference Point of the carrier. PRBs may be defined in a BWP and numbered within the BWP.

[0415] The BWP may include a UL BWP (BWP for UL) and a DL BWP (BWP for DL). One or more BWPs may be configured for a UE within one carrier.

[0416] At least one of the configured BWPs may be active, and the UE may not expect to transmit or receive a given signal / channel outside the active BWP. Note that the terms "cell," "carrier," etc. in this disclosure may be read as "BWP."

[0417] The above-described structures of radio frames, subframes, slots, minislots, symbols, etc. are merely examples. For example, the number of subframes included in a radio frame, the number of slots per subframe or radio frame, the number of minislots included in a slot, the number of symbols and RBs included in a slot or minislot, the number of subcarriers included in an RB, the number of symbols in a TTI, the symbol length, the cyclic prefix (CP) length, etc. may be changed in various ways.

[0418] Furthermore, the information, parameters, etc. described in the present disclosure may be expressed using absolute values, may be expressed using relative values ​​from a predetermined value, or may be expressed using other corresponding information. For example, a radio resource may be indicated by a predetermined index.

[0419] The names used for parameters and the like in this disclosure are not intended to be limiting in any way. Furthermore, the mathematical expressions and the like using these parameters may differ from those explicitly disclosed in this disclosure. The various channels (PUCCH, PDCCH, etc.) and information elements may be identified by any suitable names, and therefore the various names assigned to these various channels and information elements are not intended to be limiting in any way.

[0420] The information, signals, etc. described in this disclosure may be represented using any of a variety of different technologies. For example, data, instructions, commands, information, signals, bits, symbols, chips, etc. that may be referred to throughout the above description may be represented by voltages, currents, electromagnetic waves, magnetic fields or magnetic particles, optical fields or photons, or any combination thereof.

[0421] Furthermore, information, signals, etc. may be output from a higher layer to a lower layer and / or from a lower layer to a higher layer. Information, signals, etc. may be input / output via multiple network nodes.

[0422] Input and output information, signals, etc. may be stored in a specific location (for example, memory) or may be managed using a management table. Input and output information, signals, etc. may be overwritten, updated, or added. Output information, signals, etc. may be deleted. Input information, signals, etc. may be transmitted to another device.

[0423] The notification of information is not limited to the aspects / embodiments described in the present disclosure, and may be performed using other methods. For example, the notification of information in the present disclosure may be performed by physical layer signaling (e.g., Downlink Control Information (DCI) and Uplink Control Information (UCI)), higher layer signaling (e.g., Radio Resource Control (RRC) signaling, broadcast information (Master Information Block (MIB) and System Information Block (SIB)), Medium Access Control (MAC) signaling), other signals, or a combination thereof.

[0424] Note that the physical layer signaling may be referred to as Layer 1 / Layer 2 (L1 / L2) control information (L1 / L2 control signal), L1 control information (L1 control signal), etc. Furthermore, the RRC signaling may be referred to as an RRC message, such as an RRC Connection Setup message or an RRC Connection Reconfiguration message. Furthermore, the MAC signaling may be notified using, for example, a MAC Control Element (CE).

[0425] Furthermore, notification of specified information (e.g., notification that "it is X") is not limited to explicit notification, but may be made implicitly (e.g., by not notifying the specified information or by notifying other information).

[0426] The determination may be made by a value represented by one bit (0 or 1), by a Boolean value represented by true or false, or by a comparison of numerical values ​​(e.g., comparison with a predetermined value).

[0427] Software shall be construed broadly to mean instructions, instruction sets, code, code segments, program code, programs, subprograms, software modules, applications, software applications, software packages, routines, subroutines, objects, executable files, threads of execution, procedures, functions, etc., whether referred to as software, firmware, middleware, microcode, hardware description language, or otherwise.

[0428] Software, instructions, information, etc. may also be transmitted or received over a transmission medium. For example, if software is transmitted from a website, server, or other remote source using wired technologies (such as coaxial cable, fiber optic cable, twisted pair, Digital Subscriber Line (DSL)), and / or wireless technologies (such as infrared, microwave), these wired and / or wireless technologies are included within the definition of transmission media.

[0429] As used in this disclosure, the terms "system" and "network" may be used interchangeably. A "network" may refer to devices included in the network (e.g., base stations).

[0430] In the present disclosure, terms such as "precoding," "precoder," "weight (precoding weight)," "Quasi-Co-Location (QCL)," "Transmission Configuration Indication state (TCI state)," "spatial relation," "spatial domain filter," "transmit power," "phase rotation," "antenna port," "antenna port group," "layer," "number of layers," "rank," "resource," "resource set," "resource group," "beam," "beam width," "beam angle," "antenna," "antenna element," "panel," etc. may be used interchangeably.

[0431] In the present disclosure, terms such as "base station (BS)," "radio base station," "fixed station," "NodeB," "eNB (eNodeB)," "gNB (gNodeB)," "access point," "transmission point (TP)," "reception point (RP)," "transmission / reception point (TRP)," "panel," "cell," "sector," "cell group," "carrier," "component carrier," etc. may be used interchangeably. Base stations may also be referred to by terms such as macrocell, small cell, femtocell, picocell, etc.

[0432] A base station can accommodate one or more (e.g., three) cells. When a base station accommodates multiple cells, the overall coverage area of ​​the base station can be partitioned into multiple smaller areas, and each smaller area can be provided with communication service by a base station subsystem (e.g., a small indoor base station (Remote Radio Head (RRH))). The terms "cell" or "sector" refer to part or all of the coverage area of ​​a base station and / or base station subsystem that provides communication service within that coverage.

[0433] In the present disclosure, a base station transmitting information to a terminal may be interpreted as the base station instructing the terminal to control / operate based on the information.

[0434] In this disclosure, the terms "Mobile Station (MS)," "user terminal," "User Equipment (UE)," "terminal," etc. may be used interchangeably.

[0435] A mobile station may also be referred to as a subscriber station, mobile unit, subscriber unit, wireless unit, remote unit, mobile device, wireless device, wireless communication device, remote device, mobile subscriber station, access terminal, mobile terminal, wireless terminal, remote terminal, handset, user agent, mobile client, client, or some other suitable terminology.

[0436] At least one of the base station and the mobile station may be called a transmitting device, a receiving device, a wireless communication device, etc. Note that at least one of the base station and the mobile station may be a device mounted on a moving object, the moving object itself, etc.

[0437] The mobile body is a movable object that can move at any speed and naturally includes cases where the mobile body is stationary. Examples of the mobile body include, but are not limited to, vehicles, transport vehicles, automobiles, motorcycles, bicycles, connected cars, excavators, bulldozers, wheel loaders, dump trucks, forklifts, trains, buses, handcars, rickshaws, ships and other watercraft, airplanes, rockets, satellites, drones, multicopters, quadcopters, balloons, and objects mounted thereon. The mobile body may also be a mobile body that moves autonomously based on an operation command.

[0438] The mobile object may be a vehicle (e.g., a car, an airplane, etc.), an unmanned mobile object (e.g., a drone, an autonomous vehicle, etc.), or a robot (manned or unmanned). Note that at least one of the base station and the mobile station may also include devices that do not necessarily move during communication operations. For example, at least one of the base station and the mobile station may be an Internet of Things (IoT) device such as a sensor.

[0439] 39 is a diagram showing an example of a vehicle according to an embodiment. The vehicle 40 includes a drive unit 41, a steering unit 42, an accelerator pedal 43, a brake pedal 44, a shift lever 45, left and right front wheels 46, left and right rear wheels 47, axles 48, an electronic control unit 49, various sensors (including a current sensor 50, an RPM sensor 51, an air pressure sensor 52, a vehicle speed sensor 53, an acceleration sensor 54, an accelerator pedal sensor 55, a brake pedal sensor 56, a shift lever sensor 57, and an object detection sensor 58), an information service unit 59, and a communication module 60.

[0440] The drive unit 41 is configured with at least one of an engine, a motor, and a hybrid of an engine and a motor, for example. The steering unit 42 includes at least a steering wheel (also called a handle) and is configured to steer at least one of the front wheels 46 and the rear wheels 47 based on the operation of the steering wheel operated by a user.

[0441] The electronic control unit 49 is composed of a microprocessor 61, memory (ROM, RAM) 62, and a communication port (for example, an input / output (IO) port) 63. Signals are input to the electronic control unit 49 from various sensors 50-58 provided in the vehicle. The electronic control unit 49 may also be called an Electronic Control Unit (ECU).

[0442] The signals from the various sensors 50-58 include a current signal from a current sensor 50 that senses the current of the motor, a rotation speed signal of the front wheels 46 / rear wheels 47 obtained by a rotation speed sensor 51, an air pressure signal of the front wheels 46 / rear wheels 47 obtained by an air pressure sensor 52, a vehicle speed signal obtained by a vehicle speed sensor 53, an acceleration signal obtained by an acceleration sensor 54, a depression amount signal of the accelerator pedal 43 obtained by an accelerator pedal sensor 55, a depression amount signal of the brake pedal 44 obtained by a brake pedal sensor 56, an operation signal of the shift lever 45 obtained by a shift lever sensor 57, and a detection signal for detecting obstacles, vehicles, pedestrians, etc. obtained by an object detection sensor 58.

[0443] The information service unit 59 is composed of various devices, such as a car navigation system, an audio system, speakers, a display, a television, and a radio, for providing (outputting) various information such as driving information, traffic information, and entertainment information, and one or more ECUs for controlling these devices. The information service unit 59 uses information acquired from external devices via the communication module 60 or the like to provide various information / services (e.g., multimedia information / multimedia services) to the occupants of the vehicle 40.

[0444] The information service unit 59 may include input devices (e.g., keyboards, mice, microphones, switches, buttons, sensors, touch panels, etc.) that accept input from the outside, and may also include output devices (e.g., displays, speakers, LED lamps, touch panels, etc.) that output to the outside.

[0445] The driving assistance system unit 64 includes various devices for providing functions to prevent accidents and reduce the driver's driving burden, such as millimeter-wave radar, Light Detection and Ranging (LiDAR), cameras, positioning locators (e.g., Global Navigation Satellite System (GNSS)), map information (e.g., High Definition (HD) maps, Autonomous Vehicle (AV) maps), gyro systems (e.g., Inertial Measurement Units (IMUs), Inertial Navigation Systems (INSs)), artificial intelligence (AI) chips, and AI processors, as well as one or more ECUs that control these devices. The driving assistance system unit 64 also transmits and receives various information via the communication module 60 to realize driving assistance functions or autonomous driving functions.

[0446] The communication module 60 can communicate with the microprocessor 61 and components of the vehicle 40 via the communication port 63. For example, the communication module 60 transmits and receives data (information) via the communication port 63 to and from the drive unit 41, steering unit 42, accelerator pedal 43, brake pedal 44, shift lever 45, left and right front wheels 46, left and right rear wheels 47, axles 48, the microprocessor 61 and memory (ROM, RAM) 62 in the electronic control unit 49, and the various sensors 50-58, which are provided in the vehicle 40.

[0447] The communication module 60 is a communication device that can be controlled by the microprocessor 61 of the electronic control unit 49 and can communicate with an external device. For example, it transmits and receives various information to and from the external device via wireless communication. The communication module 60 may be located either inside or outside the electronic control unit 49. The external device may be, for example, the base station 10 or the user terminal 20 described above. Furthermore, the communication module 60 may be, for example, at least one of the base station 10 and the user terminal 20 described above (or may function as at least one of the base station 10 and the user terminal 20).

[0448] The communication module 60 may transmit at least one of signals from the above-mentioned various sensors 50-58 input to the electronic control unit 49, information obtained based on the signals, and information based on input from the outside (user) obtained via the information service unit 59 to an external device via wireless communication. The electronic control unit 49, the various sensors 50-58, the information service unit 59, etc. may be referred to as input units that accept input. For example, the PUSCH transmitted by the communication module 60 may include information based on the above-mentioned input.

[0449] The communication module 60 receives various information (traffic information, traffic signal information, vehicle distance information, etc.) transmitted from an external device and displays it on an information service unit 59 provided in the vehicle. The information service unit 59 may also be called an output unit that outputs information (for example, outputs information to a device such as a display or speaker based on the PDSCH received by the communication module 60 (or data / information decoded from the PDSCH)).

[0450] Furthermore, the communication module 60 stores various information received from external devices in a memory 62 that can be used by the microprocessor 61. Based on the information stored in the memory 62, the microprocessor 61 may control the drive unit 41, steering unit 42, accelerator pedal 43, brake pedal 44, shift lever 45, left and right front wheels 46, left and right rear wheels 47, axles 48, various sensors 50-58, and the like provided in the vehicle 40.

[0451] Furthermore, a base station in the present disclosure may be read as a user terminal. For example, the aspects / embodiments of the present disclosure may be applied to a configuration in which communication between a base station and a user terminal is replaced with communication between multiple user terminals (which may be called, for example, Device-to-Device (D2D) or Vehicle-to-Everything (V2X)). In this case, the user terminal 20 may be configured to have the functions of the base station 10 described above. Furthermore, terms such as "uplink" and "downlink" may be read as terms corresponding to terminal-to-terminal communication (for example, "sidelink"). For example, terms such as an uplink channel and a downlink channel may be read as a sidelink channel.

[0452] Similarly, the user terminal in the present disclosure may be read as a base station, in which case the base station 10 may be configured to have the functions of the user terminal 20 described above.

[0453] In the present disclosure, an operation described as being performed by a base station may be performed by its upper node in some cases. It is apparent that in a network including one or more network nodes having a base station, various operations performed for communication with a terminal may be performed by the base station, one or more network nodes other than the base station (such as, but not limited to, a Mobility Management Entity (MME), a Serving-Gateway (S-GW), etc.), or a combination thereof.

[0454] Each aspect / embodiment described in this disclosure may be used alone, in combination, or switched depending on the implementation. Furthermore, the order of the processing procedures, sequences, flowcharts, etc. of each aspect / embodiment described in this disclosure may be changed unless inconsistent. For example, the methods described in this disclosure present elements of various steps using an example order, and are not limited to the particular order presented.

[0455] Each aspect / embodiment described in the present disclosure may be a technology other than Long Term Evolution (LTE), LTE-Advanced (LTE-A), LTE-Beyond (LTE-B), SUPER 3G, IMT-Advanced, 4th generation mobile communication system (4G), 5th generation mobile communication system (5G), 6th generation mobile communication system (6G), xth generation mobile communication system (xG (x is, for example, an integer or decimal number)), Future Radio Access (FRA), New-Radio Access Technology (RAT), New Radio (NR), New radio access (NX), Future generation radio access (FX), Global System for Mobile communications (GSM (registered trademark)), CDMA2000, Ultra Mobile Broadband (UMB), IEEE 802.11 (Wi-Fi (registered trademark)), IEEE 802.16 (WiMAX (registered trademark)), IEEE 802.17 (WiMAX (registered trademark)), IEEE 802.19 (WiMAX (registered trademark)), IEEE 802.20 (WiMAX (registered trademark)), IEEE 802.21 (Wi-Fi (registered trademark)), IEEE 802.22 (WiMAX (registered trademark)), IEEE 802.23 (WiMAX (registered trademark)), IEEE 802.24 (WiMAX (registered trademark)), IEEE 802.25 (WiMAX (registered trademark)), IEEE 802.26 (WiMAX (registered trademark)), IEEE 802.27 (WiMAX (registered trademark)), IEEE 802.28 (WiMAX (registered trademark)), IEEE 802.29 (WiMAX (registered trademark)), IEEE 802.30 (WiMAX (registered trademark)), IEEE 802.31 (Wi-Fi (registered trademark)), IEEE 802.32 (WiMAX (registered trademark)), IEEE 802.33 (WiMAX (registered trademark)), IEEE 802. The present invention may be applied to systems that use IEEE 802.20, Ultra-WideBand (UWB), Bluetooth (registered trademark), or other suitable wireless communication methods, or to next-generation systems that are expanded, modified, created, or defined based on these. Furthermore, the present invention may be applied to a combination of multiple systems (e.g., a combination of LTE or LTE-A and 5G).

[0456] As used in this disclosure, the phrase "based on" does not mean "based only on," unless expressly stated otherwise. In other words, the phrase "based on" means both "based only on" and "based at least on."

[0457] As used in this disclosure, any reference to an element using a designation such as "first," "second," etc. does not generally limit the quantity or order of those elements. These designations may be used in this disclosure as a convenient method of distinguishing between two or more elements. Thus, a reference to a first and a second element does not imply that only two elements may be employed or that the first element must in some way precede the second element.

[0458] The term "determining" as used in this disclosure may encompass a wide variety of actions. For example, "determining" may be considered to be judging, calculating, computing, processing, deriving, investigating, looking up, search, inquiry (e.g., looking up in a table, database, or another data structure), ascertaining, etc.

[0459] Additionally, "determining" may be considered to be "determining" receiving (e.g., receiving information), transmitting (e.g., sending information), input, output, accessing (e.g., accessing data in memory), etc.

[0460] Also, "determination" may be considered to be "deciding" resolving, selecting, choosing, establishing, comparing, etc. In other words, "determination" may be considered to be "deciding" some action.

[0461] Furthermore, "judgment (decision)" may be read as "assuming," "expecting," "considering," or the like.

[0462] The "maximum transmit power" in this disclosure may mean the maximum value of transmit power, the nominal UE maximum transmit power, or the rated UE maximum transmit power.

[0463] As used in this disclosure, the terms "connected," "coupled," or any variation thereof, refer to any direct or indirect connection or coupling between two or more elements, and may include the presence of one or more intermediate elements between two elements that are "connected" or "coupled" to each other. The coupling or connection between elements may be physical, logical, or a combination thereof. For example, "connected" may be read as "access."

[0464] In this disclosure, when two elements are connected, they may be considered to be "connected" or "coupled" to one another using one or more wires, cables, printed electrical connections, etc., as well as using electromagnetic energy having wavelengths in the radio frequency range, microwave range, light (both visible and invisible) range, etc., as some non-limiting and non-exhaustive examples.

[0465] In the present disclosure, the term "A and B are different" may mean "A and B are different from each other." The term may also mean "A and B are each different from C." Terms such as "separate" and "coupled" may also be interpreted in the same way as "different."

[0466] When the terms "include," "including," and variations thereof are used in this disclosure, these terms are intended to be inclusive, similar to the term "comprising." Furthermore, when the term "or" is used in this disclosure, it is not intended to be an exclusive or.

[0467] In this disclosure, where articles are added by translation, such as a, an, and the in English, the disclosure may include that the nouns following these articles are in the plural form.

[0468] In the present disclosure, terms such as "less than or equal to," "less than," "greater than," "more than," "equal to," etc. may be interchangeable. Furthermore, in the present disclosure, terms meaning "good," "bad," "big," "small," "high," "low," "fast," "slow," "wide," "narrow," etc. may be interchangeable, not limited to the positive, comparative, and superlative. Furthermore, in the present disclosure, terms meaning "good," "bad," "big," "small," "high," "low," "fast," "slow," "wide," "narrow," etc. may be interchangeable, not limited to the positive, comparative, and superlative, as expressions with "i-th" (i is an arbitrary integer) attached (for example, "highest" may be interchangeable with "i-th highest").

[0469] In this disclosure, the terms "of," "for," "regarding," "related to," "associated with," etc. may be read interchangeably.

[0470] Although the invention according to the present disclosure has been described in detail above, it is clear to those skilled in the art that the invention according to the present disclosure is not limited to the embodiments described in the present disclosure. The invention according to the present disclosure can be implemented in modified and altered forms without departing from the spirit and scope of the invention as defined by the description of the claims. Therefore, the description of the present disclosure is intended to be illustrative and explanatory and does not impose any limiting meaning on the invention according to the present disclosure.

[0471] This application is based on Japanese Patent Application No. 2022-168370, filed on October 20, 2022, the contents of which are incorporated herein in their entirety.

Claims

1. A receiver for receiving downlink control information for scheduling uplink shared channels of ranks greater than four; a control unit that determines a combination of a plurality of demodulation reference signal (DMRS) ports based on the downlink control information, the plurality of DMRS ports includes a first set of DMRS ports corresponding to a first code division multiplexing (CDM) group and a second set of DMRS ports corresponding to a second CDM group, and the combination includes one or more DMRS ports from the first set and one or more DMRS ports from the second set.

2. The terminal described in claim 1, wherein when the rank of the uplink shared channel is 5, the combination includes three DMRS ports from the first set and two DMRS ports from the second set.

3. The terminal described in claim 1, wherein when the rank of the uplink shared channel is 6, the combination includes three DMRS ports from the first set and three DMRS ports from the second set.

4. The terminal described in claim 1, wherein when the rank of the uplink shared channel is 7, the combination includes four DMRS ports from the first set and three DMRS ports from the second set.

5. receiving downlink control information scheduling uplink shared channels of ranks greater than four; determining a combination of a plurality of demodulation reference signal (DMRS) ports based on the downlink control information; 1. A wireless communication method for a terminal, wherein the plurality of DMRS ports include a first set of DMRS ports corresponding to a first code division multiplexing (CDM) group and a second set of DMRS ports corresponding to a second CDM group, and the combination includes one or more DMRS ports from the first set and one or more DMRS ports from the second set.

6. A control unit that determines a combination of multiple demodulation reference signal (DMRS) ports for uplink shared channels with ranks greater than four; a transmitter that transmits downlink control information that schedules the uplink shared channel, the plurality of DMRS ports includes a first set of DMRS ports corresponding to a first code division multiplexing (CDM) group and a second set of DMRS ports corresponding to a second CDM group, and the combination includes one or more DMRS ports from the first set and one or more DMRS ports from the second set.

7. A system having a terminal and a base station, the terminal includes: a receiver for receiving downlink control information for scheduling uplink shared channels of ranks greater than four; a control unit that determines a combination of a plurality of demodulation reference signal (DMRS) ports based on the downlink control information, the base station includes a control unit that determines the combination; a transmitter that transmits the downlink control information, the plurality of DMRS ports includes a first set of DMRS ports corresponding to a first code division multiplexing (CDM) group and a second set of DMRS ports corresponding to a second CDM group, and the combination includes one or more DMRS ports from the first set and one or more DMRS ports from the second set.