Terminal, wireless communication method, base station and system

Abstract

A terminal according to one aspect of the present disclosure comprises: a reception unit which, when a combination of a category 1 DeModulation Reference Signal (DMRS) port and a category 2 DMRS port in at least one Code Division Multiplexing (CDM) group is supported, receives Downlink Control Information (DCI) that indicates the combination and schedules a shared channel for one or two codewords; and a control unit which controls transmission or reception of the shared channel on the basis of the combination. The combination includes an entry that indicates a DMRS port spreading over the CDM group and at least one of DMRS ports corresponding to a plurality of transmission / reception points. The control unit controls scheduling constraints of Multi User Multi Input Multi Output (MU-MIMO) when specific DMRS port mapping is assigned on the basis of the combination. According to the one aspect of the present disclosure, communication can be appropriately controlled even when the number of DMRS ports is increased compared to the related art.

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. 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, when Rel. 18 DMRS ports are introduced, which increases the number of DMRS ports, the differences in designation from Rel. 15 DMRS ports, the antenna port table to be referenced, etc. have not been fully considered. If these are not clearly defined, there is a risk that communication throughput / communication quality will not be suitably improved.

[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 control communication even when the number of DMRS ports is increased compared to conventional cases.

[0008] A terminal according to one aspect of the present disclosure includes: a receiver that receives Downlink Control Information (DCI) indicating a combination of Category 1 Demodulation Reference Signal (DMRS) ports and Category 2 DMRS ports in at least one Code Division Multiplexing (CDM) group when the terminal supports the combination; and a controller that controls transmission or reception of the shared channel based on the combination, wherein the combination includes entries indicating at least one of a DMRS port spanning the CDM group and a DMRS port corresponding to a plurality of transmission and reception points; and the controller controls Multi User Multi Input Multi Output (MU-MIMO) scheduling constraints when a specific DMRS port mapping is assigned based on the combination.

[0009] According to one aspect of the present disclosure, communication can be appropriately controlled even when the number of DMRS ports is increased compared to conventional cases.

[0010] FIG. 1 shows an example of an existing DMRS port table for DMRS configuration type 1 / 2 for PDSCH. FIG. 2 shows an example of an existing DMRS port table for DMRS configuration type 1 / 2 for PUSCH. FIGS. 3A-3C show an example of a new OCC (Orthogonal Cover Code). FIGS. 4A-4B show an example of associations between CDM groups, DMRS ports, and OCCs in Extended Type 1 / Extended Type 2. FIG. 5 shows an example of an antenna port table when DMRS type = Extended Type 1 and maximum DMRS length = 1. FIGS. 6A-6C show variations of the antenna port table when DMRS type = Extended Type 1 and maximum DMRS length = 1. FIG. 7 shows another example of an antenna port table when DMRS type = Extended Type 1 and maximum DMRS length = 1. FIG. 8 shows an example of an antenna port table when DMRS type = Extended Type 1 and maximum DMRS length = 2. FIG. 9 shows an example of an antenna port table when DMRS type = Extended Type 1 and maximum DMRS length = 2. FIGS. 10A and 10B show variations of the antenna port table when DMRS type = Extended Type 1 and maximum DMRS length = 2. FIG. 11 shows another example of an antenna port table when DMRS type = Extended Type 2 and maximum DMRS length = 1. FIG. 12 shows another example of an antenna port table when DMRS type = Extended Type 2 and maximum DMRS length = 1. FIGS. 13A and 13B show variations of the antenna port table when DMRS type = Extended Type 2 and maximum DMRS length = 1. FIG. 14 shows another example of an antenna port table when DMRS type = Extended Type 2 and maximum DMRS length = 2. FIG. 15 shows another example of an antenna port table when DMRS type = Extended Type 2 and maximum DMRS length = 2. FIG. 16 shows another example of an antenna port table when DMRS type = Extended Type 2 and maximum DMRS length = 2. 17A-17B show variations of the antenna port table when DMRS type=extended type 2 and DMRS maximum length=2.18A and 18B are diagrams illustrating an example of association of CDM groups, DMRS ports among multiple UEs, and OCCs when DMRS type = Type 1 / Type 2. FIGS. 19A and 19B are diagrams illustrating an example of association of CDM groups, DMRS ports among multiple UEs, and OCCs when DMRS type = Extended Type 1 / Extended Type 2. FIG. 20 shows a modified example of an antenna port table when DMRS type = Extended Type 1 and maximum DMRS length = 1. FIG. 21 is a diagram illustrating an example of a schematic configuration of a wireless communication system according to an embodiment. FIG. 22 is a diagram illustrating an example of a configuration of a base station according to an embodiment. FIG. 23 is a diagram illustrating an example of a configuration of a user terminal according to an embodiment. FIG. 24 is a diagram illustrating an example of hardware configurations of a base station and a user terminal according to an embodiment. FIG. 25 is a diagram illustrating an example of a vehicle according to an embodiment.

[0011] (DMRS) The front-loaded Demodulation Reference Signal (DMRS) is the first (first symbol or symbol close to the first) DMRS for faster demodulation. An additional DMRS can be configured by RRC for high-speed mobile terminals (user terminals, User Equipment (UE)) or high modulation and coding schemes (MCS) / ranks. The frequency location of the additional DMRS is the same as that of the front-loaded DMRS.

[0012] 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.

[0013] 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.

[0014] For the frequency domain, (PDSCH / PUSCH) DMRS configuration type 1 or 2 is configured. DMRS configuration type 1 has a comb structure and is applicable to both CP-OFDM (transport precoding=disabled) and DFT-S-OFDM (transport precoding=enabled). DMRS configuration type 2 is applicable only to CP-OFDM.

[0015] Single symbol DMRS or double symbol DMRS is configured.

[0016] 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 maximum number (maxLength) in the uplink DMRS configuration (DMRS-UplinkConfig) is not configured, single-symbol DMRS is used.

[0017] Double-symbol DMRS is used for more DMRS ports (especially Multi-User Multiple Input Multiple Output (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 number (maxLength) in the uplink DMRS configuration (DMRS-UplinkConfig) is 2 (len2), whether it is single-symbol DMRS or double-symbol DMRS is determined by DCI or configured grant.

[0018] 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

[0019] Multiple DMRS ports that are mapped to the same resource element (RE, time and frequency resource) are called a DMRS Code Division Multiplexing (CDM) group.

[0020] 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 a frequency domain OCC (FD OCC) of length 2. Between multiple DMRS CDM groups (two DMRS CDM groups), two DMRS ports are multiplexed using frequency division multiplexing (FDM).

[0021] 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 Time Domain OCC (TD OCC). Between multiple DMRS CDM groups (two DMRS CDM groups), two DMRS ports are multiplexed by FDM.

[0022] 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.

[0023] 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.

[0024] Here, an example of DMRS mapping type B is shown, but DMRS mapping type A is also similar.

[0025] In the parameters for PDSCH DMRS (existing table, existing DMRS port table, FIG. 1), DMRS ports 1000-1007 can be used for DMRS configuration type 1, and DMRS ports 1000-1011 can be used for DMRS configuration type 2.

[0026] In the parameters for PUSCH DMRS (existing table, existing DMRS port table, FIG. 2), DMRS ports 0-7 can be used for DMRS configuration type 1, and DMRS ports 0-11 can be used for DMRS configuration type 2.

[0027] (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.

[0028] 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.

[0029] 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.

[0030] 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 setting type 1) and up to 12 ports for Type 2 DMRS (i.e., DMRS setting type 2).

[0031] In Rel-15 NR, a comb-like transmission frequency pattern (comb-like resource set) is used as the FDM. Cyclic Shift (CS) is used as the FD-OCC. Furthermore, the TD-OCC can only be applied to double-symbol DMRS.

[0032] The OCC in the present disclosure may be interchangeably read as orthogonal code, orthogonalization, cyclic shift, and the like.

[0033] The type of DMRS may be referred to as a DMRS configuration type.

[0034] 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.

[0035] 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.

[0036] 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).

[0037] 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}).

[0038] 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.

[0039] 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.

[0040] 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.

[0041] 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.

[0042] 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.

[0043] 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').

[0044] The TD-OCC and FD-OCC of the DMRS in Rel. 15 NR both correspond to OCCs with a sequence length (which may also be referred to as OCC length) of 2. For example, Rel. 15 Type 1 / Type 2 DMRS ports (e.g., rel. 15 Type 1 / Type 2 DMRS ports) may be defined as DMRS ports with an FD-OCC length of 2 (e.g., DMRS ports with FD-OCC length = 2).

[0045] Therefore, the possible values ​​of k' and l' are both 0 and 1. By multiplying this FD-OCC in units of RE, it is possible to multiplex two-port DMRS using the same time and frequency resource (2 RE). When both this FD-OCC and TD-OCC are applied, it is possible to multiplex four-port DMRS using the same time and frequency resource (4 RE).

[0046] The two existing DMRS port tables (association of antenna port numbers with parameters) 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.

[0047] For example, for antenna ports 1000 and 1001, {wｆ (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.

[0048] 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.

[0049] 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.

[0050] 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.

[0051] 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.

[0052] 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.

[0053] To increase the number of DMRS ports, the following five options (methods for increasing the number of DMRS ports) are being considered.

[0054] <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.

[0055] <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.

[0056] <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.

[0057] <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.

[0058] <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.

[0059] Options 1 / 3 may be supported. In addition, TD OCC may be supported. The difference between options 2 and 5 may be whether semi-static switching based on RRC or dynamic switching based on DCI is supported between FD-OCC and TD-OCC.

[0060] In option 5 of the above-mentioned DMRS port number increasing method, as shown in the example of FIG. 3, a new FD-OCC of length 4 is applied, and a new TD-OCC of length 2 is applied to multiple discontinuous DMRS symbols, and the number of DMRS ports in one CDM group may be 4. In this case, the receiving side can separate signals by decoding either the FD-OCC or the TD-OCC, which is advantageous compared to option 1 / 3. For example, if using a TD-OCC causes problems such as degradation of characteristics (orthogonality) during high-speed movement, or channel estimation cannot be started even when only the preceding DMRS symbol is received, and additional DMRS symbols must be received, resulting in a delay in PDSCH decoding, the receiving side can decode using only the FD-OCC. For example, if using an FD-OCC causes problems such as degradation of characteristics (orthogonality) when the delay spread is large, the receiving side can decode using only the TD-OCC.

[0061] In the aforementioned option 5 for increasing the number of DMRS ports, a new FD-OCC of length 6 may be applied, and a new TD-OCC of length 2 may be applied to multiple non-consecutive DMRS symbols.

[0062] Thus, new FD-OCCs longer than 2 are supported in Rel. 18 and later. DMRS ports for Type 1 / Type 2 for Rel. 18 and later may be referred to as Rel. 18 enhanced type 1 / enhanced type 2 DMRS ports, for example. Enhanced type 1 / enhanced type 2 may be referred to as eType 1 / eType 2.

[0063] For example, a Rel. 18 eType1 / eType2 DMRS port may be defined with an FD-OCC length greater than 2. For example, the FD-OCC length of a Rel. 18 eType1 / eType2 DMRS port may be 4.

[0064] Note that a Type 1 / Type 2 DMRS port with FD-OCC length = 2 defined in Rel. 15 may be referred to as a Rel. 15 Type 1 / Type 2 DMRS port.

[0065] Rel. 18 e Type 1 DMRS ports may have port index p=#1000-#1015. For example, the same DMRS port index (DMRS port #1000-#1007) as the Rel. 15 DMRS ports may be used for DMRS ports with new FD-OCCs #0 and #1. DMRS ports with new FD-OCCs #2 and #3 may use different DMRS port indexes (DMRS port #1008-#1015) from the Rel. 15 DMRS ports.

[0066] Rel. 18 e Type 2 DMRS ports may have port index p = #1000-1023. For DMRS ports with new FD-OCCs #0 and #1, the same DMRS port index (DMRS ports #1000-#1011) as for Rel. 15 DMRS ports may be used. For DMRS ports with new FD-OCCs #2 and #3, different DMRS port index (DMRS ports #1012-#1023) may be used.

[0067] (New OCC for DMRS of PDSCH / PUSCH) Rel. 18 supports the FD-OCC of length 4 and the TD-OCC of length 2 as new OCCs for DMRS of PDSCH / PUSCH (Extended Type 1 / Extended Type 2 DMRS). Figures 3A to 3C are diagrams showing examples of the new OCCs. The FD-OCC and TD-OCC may also be simply referred to as OCCs.

[0068] As shown in FIG. 3A, a length-4 FD-OCC based on a 4-by-4 Walsh matrix (sequence) may be defined. In FIG. 3A, four sequences are obtained for FD-OCC index i={0, 1, 2, 3}. The Walsh matrix may be replaced with a Hadamard code (e.g., a Hadamard code). An OCC based on a Walsh matrix (sequence) is useful for DL ​​reception (e.g., reception of a PDSCH).

[0069] A cyclic shift-based OCC of length 4 may be defined as shown in Figure 3B. In Figure 3B, four sequences are obtained by using cyclic shifts {i·0, i·π, i·π / 2, i·3π / 2} for FD-OCC index i={0, 1, 2, 3}. Cyclic shift-based OCCs are useful for UL transmissions (e.g., PUSCH transmissions).

[0070] A TD-OCC of length 2 may be defined as shown in Figure 3C, where two sequences are obtained for TD-OCC index i={0,1}.

[0071] Furthermore, a table (association of port indexes, CDM group indexes, and new OCC indexes) for enhanced type 1 / enhanced type 2 DMRS may be defined in association with the OCC shown in Fig. 3. The port index of the PDSCH may be indicated by a number obtained by adding 1000 to the port index of the PUSCH.

[0072] The novel FD-OCC may be any of the OCCs described above.

[0073] In Figures 3A and 3B, the first and second halves of OCCs #0 and #1 (OCCs corresponding to OCC indexes 0 and 1) of length 4 are the same as, for example, OCCs #0 and #1 (OCCs corresponding to OCC indexes 0 and 1) of length 2 shown in Figure 3C.

[0074] In this disclosure, the OCC (FD-OCC / TD-OCC) corresponding to OCC index i may be referred to as OCC#i.

[0075] Some of the sequences of the new FD-OCC may be associated with a Rel. 15 DMRS port index.

[0076] When a length 2 FD-OCC is used, the Rel. 15 DMRS port table for DMRS configuration type 1 and the Rel. 15 DMRS port table for DMRS configuration type 2 may be used.

[0077] The extended DMRS configuration type 1 (DMRS extension type 1, DMRS extension type = 1, DMRS eType 1) uses the frequency domain configuration of the DMRS configuration type 1 (DMRS type 1, DMRS type = 1, DMRS Type 1) and a new FD-OCC. The extended DMRS configuration type 2 (DMRS extension type 2, DMRS extension type = 2, DMRS eType 2) uses the frequency domain configuration of the DMRS configuration type 2 (DMRS type 2, DMRS type = 2, DMRS Type 2) and a new FD-OCC.

[0078] In the present disclosure, DMRS configuration type 1, DMRS type 1, DMRS type=1, and DMRS Type 1 may be interchangeable. In the present disclosure, DMRS configuration type 2, DMRS type 2, DMRS type=2, and DMRS Type 2 may be interchangeable. In the present disclosure, extended DMRS configuration type 1, DMRS extended type 1, DMRS extended type=1, and DMRS eType 1 may be interchangeable. In the present disclosure, extended DMRS configuration type 2, DMRS extended type 2, DMRS extended type=2, and DMRS eType 2 may be interchangeable.

[0079] In the present disclosure, the DMRS maximum length and maxLength may be read interchangeably.

[0080] In this disclosure, existing FD-OCC, length 2 FD-OCC, Rel. 15 FD-OCC, w f (k') may be interchangeable. In each embodiment, the new FD-OCC, the FD-OCC longer than 2, the Rel. 18 FD-OCC, w f (k') may be read interchangeably.

[0081] (CDM Group) As mentioned above, multiple DMRS ports that are mapped to the same RE (time and frequency resource) may be referred to as a DMRS CDM group.

[0082] Fig. 4A is a diagram showing an example of association between CDM groups, DMRS ports, and OCCs in Extended Type 1. Fig. 4B is a diagram showing an example of association between CDM groups, DMRS ports, and OCCs in Extended Type 2. The DMRS ports in Figs. 4A and 4B may be referred to as extended DMRS ports. Note that Figs. 4A and 4B are applicable to both single-symbol DMRS and double-symbol DMRS.

[0083] As shown in Figure 4A, eight DMRS ports (ports #0-3, 8-11) can be used for DMRS configuration extension type 1 and single-symbol DMRS. Within each DMRS CDM group (CDM group #0-1), four DMRS ports (ports #0-1, 8-9, port #2-3, 10-11) are multiplexed using a length-4 FD-OCC (FD-OCC #0-3). Between multiple DMRS CDM groups (two DMRS CDM groups (CDM group #0-1)), two DMRS ports are multiplexed using FDM.

[0084] Also, as shown in FIG. 4A , in the case of DMRS configuration extension type 1 and double-symbol DMRS, eight more DMRS ports (ports #4-7, 12-15) can be used. Within each DMRS CDM group (CDM group #0-1), four DMRS ports (ports #4-5, 12-13, port #6-7, 14-15) are multiplexed using a FD-OCC #0-3 of length 4. Between multiple DMRS CDM groups (two DMRS CDM groups (CDM group #0-1)), two DMRS ports are multiplexed using FDM. Furthermore, two DMRS ports in the time direction are multiplexed using a TD-OCC #0-1 of length 2. That is, multiple (two) CDM groups with the same index are multiplexed using TDM.

[0085] In the extension type 1 shown in FIG. 4A, the DMRS ports corresponding to CDM group #0 are {port#0,1,8,9} and {port#4,5,12,13}, and the DMRS ports corresponding to CDM group #1 are {port#2,3,10,11} and {port#6,7,14,15}.

[0086] As shown in Figure 4B, 12 DMRS ports (ports #0-5, 12-17) can be used for DMRS configuration extension type 2 and single-symbol DMRS. Within each DMRS CDM group (CDM group #0-2), four DMRS ports (ports #0-1, 12-13, port #2-3, 14-15, port #4-5, 16-17) are multiplexed using a length-4 FD-OCC (FD-OCC #0-3). Between multiple DMRS CDM groups (three DMRS CDM groups (CDM group #0-2)), three DMRS ports are multiplexed using FDM.

[0087] Also, as shown in FIG. 4B , in the case of DMRS configuration extension type 2 and double-symbol DMRS, an additional 12 DMRS ports (ports #6-11, 18-23) can be used. Within each DMRS CDM group (CDM group #0-2), four DMRS ports (ports #6-7, 18-19, port #8-9, 20-21, port #10-11, 22-23) are multiplexed using a FD-OCC #0-3 of length 4. Between multiple DMRS CDM groups (three DMRS CDM groups (CDM group #0-2)), three DMRS ports are multiplexed using FDM. Furthermore, two DMRS ports in the time direction are multiplexed using a TD-OCC #0-1 of length 2. That is, multiple (two) CDM groups with the same index are multiplexed using TDM.

[0088] In the extended type 2 shown in Figure 4B, the DMRS ports corresponding to CDM group #0 are {port #0, 1, 12, 13} and {port #6, 7, 18, 19}, the DMRS ports corresponding to CDM group #1 are {port #2, 3, 14, 15} and {port #8, 9, 20, 21}, and the DMRS ports corresponding to CDM group #2 are {port #4, 5, 16, 17} and {port #10, 11, 22, 23}.

[0089] (DMRS Port Combinations) In antenna port indication of DMRS ports for PDSCH with DMRS maximum length = 1 / 2, Extended Type 1, and Extended Type 2, it is considered that all of the port combinations in the following categories can be indicated: (Category 1) Combinations of multiple indexes of existing ports (p = 0 to 7 for Extended Type 1, p = 0 to 11 for Extended Type 2). (Category 2) Combinations of multiple indexes of new ports (p = 8 to 15 for Extended Type 1, p = 12 to 23 for Extended Type 2). (Category 3) Combinations of existing port indexes and new port indexes within one CDM group with at least DMRS max length = 1 (for Extended Type 1, at least one combination of up to 4 ports from p = {0,1,8,9} and up to 4 ports from p = {2,3,10,11}; for Extended Type 2, at least one combination of up to 4 ports from p = {0,1,12,13} and up to 4 ports from p = {2,3,14,15}). For up to 4 ranks, only one CDM group is used. For more than 4 ranks, more than one CDM group can be used.

[0090] The DMRS port for the PDSCH is determined by p+1000.

[0091] It is being considered that maximum DMRS length = 1 and rank = 5, 6, 7, 8 will be supported in the DMRS port of Extended Type 1 / Extended Type 2 for PDSCH / PUSCH.

[0092] (MU-MIMO Scheduling Constraints) For MU-MIMO, multiple DMRSs for multiple UEs are multiplexed. Multiple DMRSs may be CDM'd using different OCCs within one CDM group, or FDM'd using different subcarriers (combs) between multiple CDM groups. In CDM, problems arise due to differences in distance from the base station to multiple UEs (near-far problem). If FD-OCC is used in a flat fading environment, no inter-symbol interference occurs, but if FD-OCC is used in a frequency-selective fading environment, inter-symbol interference occurs and quality deteriorates. To prevent this, MU-MIMO scheduling constraints (existing MU-MIMO scheduling constraints) are specified.

[0093] Similarly, if TD-OCC is used in an environment where there is no fluctuation in the channel conditions in the time domain (stationary state), no inter-symbol interference will occur, but if TD-OCC is used in an environment where there is fluctuation in the channel conditions in the time domain (mobile state), inter-symbol interference will occur and quality will be reduced.

[0094] The following MU-MIMO scheduling constraints are specified for PDSCH with DMRS configuration type 1: In DMRS configuration type 1, if a UE is scheduled with one codeword (CW) and is assigned an antenna port mapping with indices {2, 9, 10, 11, 30} in the existing antenna port table for DMRS configuration type 1, or if the UE is scheduled with two CWs, the UE may assume that the remaining orthogonal antenna ports are not associated with transmitting PDSCH to another UE.

[0095] For the case where the number of DMRS CDM groups without data is 1 and the rank is 1 (one DMRS port), there may be no restriction within the same CDM group (one DMRS port of another UE may be CDMed to the DMRS port of the UE). For the case where the number of DMRS CDM groups without data is 1 and the rank is 2 (two DMRS ports), all DMRS ports within the same CDM group are indicated, so the DMRS port of the UE cannot be CDMed to the DMRS port of another UE within the same CDM group. For the case where the number of DMRS CDM groups without data is 2 and the rank is 3 (three DMRS ports), three DMRS ports out of four DMRS ports within two CDM groups are indicated, so one DMRS port is free, but one DMRS port of another UE cannot be CDMed there. DMRS without Data For the case where the number of CDM groups is 2 and rank is 4 (4 DMRS ports), all DMRS ports in the same CDM group are indicated, so that the DMRS port of the UE cannot be CDMed with the DMRS port of another UE in the same CDM group.

[0096] If a UE is configured with a Rel. 18 DMRS port, the UE may adhere to at least one of the following constraints:

[0097] - Constraint 1: The existing MU-MIMO scheduling constraints apply. This means that many DMRS ports cannot be used by other UEs. For example, for ranks greater than 4, 2CW, if category 1 / 2 DMRS port combinations are used, the free ports cannot be used by other UEs.

[0098] - Constraint 2: MU-MIMO scheduling constraints are updated. The UE may comply with at least one of the following constraints: -- Constraint 2-1: There are no existing MU-MIMO scheduling constraints. There may be no MU-MIMO scheduling constraints for Rel. 18 DMRS ports. -- Constraint 2-2: Some new MU-MIMO scheduling constraints are introduced. -- Constraint 2-3: There are no MU-MIMO scheduling constraints across different CDM groups, and new MU-MIMO scheduling constraints within one CDM group are introduced.

[0099] The MU-MIMO scheduling constraint in constraint 1 may be that in extended type 2, when a DMRS port combination using two CDM groups #0 and #1 is indicated, a DMRS port in another CDM group #2 cannot be applied to another UE.

[0100] The MU-MIMO scheduling constraint in constraint 2-3 may be such that in extended type 2, when a DMRS port combination using two CDM groups #0 and #1 is indicated, a DMRS port in another CDM group #2 may be assigned to another UE.

[0101] (Analysis) When Rel. 18 DMRS ports are used, it is expected that PUSCH / PDSCH scheduling for one / two codewords (CWs) will be controlled. However, the antenna port table and other information referenced in such cases have not been fully considered. If these are not clearly defined, there is a risk that communication throughput / communication quality will not be suitably improved.

[0102] Therefore, the present inventors have conceived a control method when a Rel. 18 DMRS port is defined.

[0103] Hereinafter, embodiments according to the present disclosure will be described in detail with reference to the drawings. Note that each of the following embodiments (e.g., each case) may be used alone or in combination of at least two of them.

[0104] (Various Alternative Readings, etc.) In the present disclosure, "A / B" and "at least one of A and B" may be interchangeable. Also, in the present disclosure, "A / B / C" may mean "at least one of A, B, and C."

[0105] In the present disclosure, terms such as 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.

[0106] In the present disclosure, Radio Resource Control (RRC), RRC parameters, RRC messages, higher layer parameters, 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.

[0107] 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, etc., or a combination thereof.

[0108] 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.

[0109] In the present disclosure, physical layer signaling may be, for example, Downlink Control Information (DCI), Uplink Control Information (UCI), and the like.

[0110] 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.

[0111] In the present disclosure, the terms 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.

[0112] Note that the CORESET pool may be interchangeably read as the CORESET pool index.

[0113] 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.

[0114] In the present disclosure, DMRS, DL DMRS, UL DMRS, PDSCH DMRS, and PUSCH DMRS may be read as interchangeable terms.

[0115] In the present disclosure, RE, RB, and PRB may be read interchangeably.

[0116] In the present disclosure, orthogonal sequence, OCC, FD OCC, and TD OCC may be interpreted as interchangeable.

[0117] 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.

[0118] 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.

[0119] 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)).

[0120] 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.

[0121] 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.

[0122] In the present disclosure, "transform precoding is configured" may be read interchangeably as "transform precoding is enabled."

[0123] It should be noted that in this disclosure, "having the capability of..." may be read interchangeably as "supporting / reporting the capability of...".

[0124] In the present disclosure, a table may be read interchangeably as one or more tables.

[0125] 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.

[0126] 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.

[0127] In the present disclosure, 8Tx and UL transmission of more than four layers / ranks may be read interchangeably.

[0128] In the present disclosure, Rel. 15 DMRS ports, Rel. 15 Type 1 / 2 DMRS ports, and existing DMRS ports may be interchangeable. In the present disclosure, Rel. 18 DMRS ports, Rel. 18 Extended Type 1 / 2 DMRS ports, and new DMRS ports may be interchangeable. Note that Rel. 18 DMRS ports may correspond to DMRS ports with a total number of ports specified that is twice or more (e.g., twice, three times, four times, etc.) that of Rel. 15 DMRS ports.

[0129] In the present disclosure, a DMRS when the use of a Rel. 15 DMRS port is configured or the use of a Rel. 18 DMRS port is not configured (enabled) may be referred to as a Rel. 15 DMRS. In the present disclosure, a DMRS when the use of a Rel. 18 DMRS port is configured (enabled) may be referred to as a Rel. 18 DMRS. Among the Rel. 15 DMRS, a DMRS for Type 1 / 2 may be referred to as a Rel. 15 Type 1 / 2 DMRS, simply Type 1 / 2 DMRS, etc. Among the Rel. 18 DMRS, a DMRS for extended Type 1 / 2 may be referred to as a Rel. 18 extended Type 1 / 2 DMRS, simply extended Type 1 / 2 DMRS, etc.

[0130] 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.

[0131] 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.

[0132] In each embodiment, the terms "a Rel. 18 DMRS port is configured" and "a DMRS extension type 1 / 2 is configured" may be interpreted as interchangeable.

[0133] In the antenna port table of each embodiment, the values ​​of the antenna port field value, the number of DMRS CDM groups without data, and the DMRS port are merely examples, and other values ​​may be defined.

[0134] In the new antenna port table when using Rel. 18 DMRS ports, some or all of the DMRS port combinations in the existing antenna port table may be reused. In this case, only DMRS ports among DMRS ports 0 to 7 may be specified for DMRS extension type 1, and only DMRS ports among DMRS ports 0 to 11 may be specified for DMRS extension type 2.

[0135] In each embodiment, the application of multiple TCI states in transmission and reception using multiple TRPs is mainly described in terms of a method for two TRPs (i.e., when at least one of N and M is 2), but the number of TRPs may be three or more (multiple), and each embodiment may be applied to correspond to the number of TRPs. In other words, at least one of N and M may be a number greater than 2.

[0136] Each embodiment may be applied to the DMRS of the PDSCH or the DMRS of the PUSCH. The PUSCH DMRS port index may be represented as p, and the PDSCH DMRS port index may be represented as p + 1000. Furthermore, p may be replaced with Value (row index) in the table of the present disclosure.

[0137] Each embodiment may be applied to a single-symbol DMRS or a double-symbol DMRS. Each embodiment may be applied to a DMRS configuration type 1 or a DMRS configuration type 2.

[0138] Each embodiment may be applied to DMRS Extension Type 1 or DMRS Extension Type 2. Each embodiment may be applied to DMRS Max Length=1 or DMRS Max Length=2.

[0139] In each embodiment, the MU-MIMO scheduling constraint and the constraint that free (remaining) orthogonal DMRS ports are not used for another UE may be read interchangeably.

[0140] (Wireless Communication Method) The DMRS port of the PDSCH may be specified by an antenna port field in a DCI format (eg, DCI format 1_1 / 1_2) for scheduling the PDSCH.

[0141] The DMRS port of the PUSCH may be specified by the antenna port field in the DCI format for scheduling the PUSCH (e.g., DCI format 0_1 / 0_2).

[0142] The UE may refer to a new antenna port table (which may also be referred to as an antenna port table, an antenna port indication table, etc.) to determine the antenna port corresponding to the value of the antenna port field.

[0143] Note that a UE's use of a Rel. 15 DMRS port may mean that it uses (can use) antenna port index p of p = #0 to #7 for Type 1 and p = #0 to #11 for Type 2. Also, a UE's use of a Rel. 18 DMRS port may mean that it uses (can use) antenna port index p of p = #0 to #15 (or #8 to #15) for Type 1 and p = #0 to #23 (or #12 to #23) for Type 2.

[0144] In the present disclosure, the port index for the PDSCH / PUSCH DMRS may correspond to a number obtained by adding 1000 to the illustrated number (for example, #1000), or may correspond to the illustrated number itself (for example, #0). The port index for the PDSCH / PUSCH DMRS may correspond to a number obtained by adding or subtracting 1000 to the port index for the PDSCH / PUSCH DMRS, or may be the same as the port index for the PDSCH / PUSCH DMRS.

[0145] The new antenna port table may be a table for Rel. 18 Extended Type 1 / 2 DMRS ports. The new antenna port table preferably includes, in DCI codepoints (or table row entries), a combination of at least one DMRS port from the following Categories 1 to 3, for a maximum number (which may be referred to as maximum length and may be given by the upper layer parameter maxLength) of 1 or 2: Category 1: Legacy DMRS ports only (DMRS ports defined up to Rel. 17; p = #0 to #7 for eType 1, p = #0 to #11 for eType 2), Category 2: New DMRS ports only (DMRS ports additionally defined in Rel. 18 and later; p = #8 to #15 for eType 1, p = #12 to #23 for eType 2), Category 3: Legacy DMRS ports and new DMRS ports in at least one CDM group.

[0146] The new DMRS port combination of Category 2 may be a combination obtained by adding X to the port index of the DMRS port combination of Category 1. For example, X may be a number equal to or greater than 8 (e.g., 8) for eType 1, or a number equal to or greater than 12 (e.g., 12) for eType 2. The value X may be predefined in a standard, configured in the UE by higher layer signaling, or determined based on UE capabilities. The value X may be referred to as an offset indicator (offset index), or simply as an offset.

[0147] Legacy DMRS ports and new DMRS ports in Category 3 may correspond to, for example, the following combinations: Number of ranks in a CDM group: 3 or 4. Index of the CDM group: 0, 1 for eType1; 0, 1, 2 for eType2. The number of CDM groups without data: 1, 2 for eType1; 1, 2, 3 for eType2.

[0148] Note that the legacy DMRS ports and new DMRS ports of Category 3 do not have to include all of the above combinations. For example, the number of CDM groups without data corresponding to legacy DMRS ports and new DMRS ports of Category 3 may be specified as either 1 or 2 or both (corresponding code points) in the antenna port table for eType 1, or as either 1, 2, or 3 or more (corresponding code points) in the antenna port table for eType 2.

[0149] Also, a Category 3 DMRS port may be a legacy DMRS port and a new DMRS port of a particular rank (e.g., rank 3 / 4) within the same CDM group.

[0150] Also, Category 3 DMRS ports may include the following combinations of legacy DMRS ports and new DMRS ports in at least one CDM group: - for eType1, p = {#0,1,8,9} or {#2,3,10,11}, up to 4 ports, - for eType2, p = {#0,1,12,13}, {#2,3,14,15}, or {#4,5,16,17}, (The above combinations may be applied in at least a single TRP.

[0151] In Category 3, only one CDM group may be used per UE up to rank 4. For ranks 4 and above, multiple CDM groups may be used per UE.

[0152] In the following embodiments, examples of antenna port tables for PDSCH DMRS are shown, but the scope of coverage of the present disclosure is not limited to this. For example, the antenna port tables (configuration methods) in the following embodiments may be appropriately replaced with antenna port tables (configuration methods) for PUSCH DMRS.

[0153] For example, the DCI in the following embodiments may correspond to a DCI format for PDSCH (for example, DCI format 1_1 / 1_2) or a DCI format for PUSCH (for example, DCI format 0_1 / 0_2).

[0154] Also, the antenna port table for PUSCH DMRS may differ from the antenna port table for PDSCH DMRS and may include only DMRS ports for one rank. The UE may be instructed on the number of ranks (number of layers) for PUSCH DMRS, for example, using the precoding information and number of layers fields.

[0155] The antenna port table in the following embodiment illustrates an example in which all of the above Category 1-3 DMRS port combinations are included in any DCI code point (or row entry of the table), but is not limited to this. For example, an antenna port table that does not include at least one of Category 1, 2, and 3 DMRS port combinations may be configured / used based on the contents of the present disclosure.

[0156] In the antenna port tables of the following embodiments, the "Notes" column is a supplementary explanation and may not be included in the table (may not be specified). In the antenna port tables of the following embodiments, not all rows may be specified for each category (some rows may be omitted), and rows (combinations) that are not listed may be specified / added. In addition, in the antenna port table, the correspondence between the combination of DMRS port indices, the number of DMRS CDM groups without data, the row index, and the corresponding entries (various values ​​in the table) may be different. That is, the order of the rows may be reversed. Furthermore, when some rows are omitted / deleted (not specified), the indexes (values) of the subsequent rows may be moved up.

[0157] In addition, in the present disclosure, the value of the antenna port field may be read as a row index.

[0158] Also, in the present disclosure, single TRP may be interpreted as one transmission / reception point, and multi-TRP may be interpreted as multiple transmission / reception points.

[0159] In addition, in each antenna port table of the following embodiments, (1) the antenna port table for single TRP (to indicate single TRP operation) may include at least entries excluding entries marked with [ ]. Also, (2) the antenna port table for multi-TRP (to indicate multi-TRP operation) may include entries marked with [ ] in addition to the entries in the antenna port table for single TRP described above. The entries marked with [ ] may be associated with, for example, DMRS ports (antenna ports corresponding to multi-TRP) spanning CDM groups.

[0160] That is, each of the antenna port tables shown below may be defined separately for each of the above (1) and (2) or for each category. In this case, the antenna port table to be used may be switched depending on the applied scenario (single TRP / multi-TRP, or any of categories 1 to 3). By switching the antenna port table (the number of rows) depending on the scenario, the antenna port table can be specified flexibly and efficiently. Furthermore, the antenna port table may be defined as a single table that combines the above (1) and (2).

[0161] Furthermore, the above-mentioned scenario switching may be performed based on higher layer signaling. Scenario switching may not be performed, and only the antenna port table for multi-TRP may be used. In other words, the antenna port table for multi-TRP may also serve as the antenna port table for single-TRP.

[0162] Furthermore, the DMRS port of the PDSCH is not limited to the antenna port field in a DCI format for scheduling the PDSCH (e.g., DCI format 1_1 / 1_2), but may be indicated by another existing field, a new DCI field, or a combination of these fields and the antenna port field. Furthermore, a specific DMRS port may be indicated by combining a new indicator with an existing field such as a Time Domain Resource Assignment / Allocation (TDRA) field / Frequency Domain Resource Assignment / Allocation (FDRA) field.

[0163] In addition, in the present disclosure, the antenna port table for single-TRP and the antenna port table for multi-TRP may be defined separately, or a common antenna port table may be defined. In either antenna port table, the size of the antenna port field included in DCI format 1_1 / 1_2 may be different. In this case, the size of the antenna port field for single-TRP may be smaller than the antenna port field for multi-TRP. More specifically, for example, the size of the antenna port field for single-TRP may be 4 bits, and the antenna port field for multi-TRP may be 5 bits.

[0164] First Embodiment The first embodiment relates to an antenna port field for PDSCH.

[0165] [Embodiment 1.1] In embodiment 1.1, a case will be described where DMRS type = extended type 1 and DMRS maximum length = 1. Fig. 5 shows an example of an antenna port table when DMRS type = extended type 1 and DMRS maximum length = 1.

[0166] In Figure 5, the left side of the table corresponds to four layers or less and is referred to when a PDSCH with one codeword is scheduled, while the right side of the table corresponds to five layers or more and is referred to when a PDSCH with two codewords is scheduled.

[0167] The antenna port table (on the left side) in this example includes DMRS port combinations that include only Category 1 DMRS ports (existing ports), DMRS port combinations that include only Category 2 DMRS ports (new ports), and DMRS port combinations that include Category 3 DMRS ports (both existing and new ports).

[0168] In the case of one code word (1 CW) in this example, the antenna port field values ​​(Value)=0-11 correspond to category 1, 12-23 correspond to category 2, and 24-29 correspond to category 3.

[0169] In this example, the X for a Category 2 DMRS port is 8 (the DMRS port indexes corresponding to the antenna port field values ​​12-23 correspond to the DMRS port indexes corresponding to the antenna port field values ​​0-11 all increased by 8). X may be referred to as an offset indicator (offset index) or simply as an offset. In this case, the offset is represented by +8.

[0170] The DMRS port combinations for Category 3 DMRS ports in this example (corresponding to values ​​of the antenna port field=24-29) are for rank 3 or 4 and include only DMRS ports within the same CDM group.

[0171] In the case of two codewords (2CW) in the table of Figure 5, the values ​​(Value) = 0 to 3 in the antenna port field correspond to ranks 5 to 8, respectively. Since the maximum DMRS length = 1, DMRS for two codewords can be transmitted in one DMRS symbol.

[0172] In addition, the UE may be configured by the base station with information on the maximum number of code words that can be scheduled by DCI (e.g., RRC parameter maxNrofCodeWordsScheduledByDCI), and may determine to refer to the right side of the antenna port table if the information indicates a value greater than 1 and the DCI includes multiple specific fields (e.g., MCS fields).

[0173] In the DMRS port combinations for 1 CW (left half of the table) in embodiment 1.1, row entries (which may simply be referred to as entries) indicated in square brackets ([ ]) will be specifically described. The value of the antenna port field, Value, and row index may be interchangeable.

[0174] In Figure 5, entries with antenna port field values ​​(Value) = 0-2, 12-14, 24-25 may be associated with a DMRS CDM group number of 1 without data (i.e., DMRS and data are FDMed). According to this entry, even in MU-MIMO, data and DMRS can be temporarily FDMed depending on traffic volume, etc., to maximize UE throughput. In other words, these entries may be applied not only to SU-MIMO but also to MU-MIMO.

[0175] Entries with antenna port field values ​​9-11, 21-23 may be associated with DMRS CDM group number = 2 without data. These entries may correspond to rank 3 / 4. These entries may not be included in a single TRP.

[0176] Although entries corresponding to rank 3 / 4 already exist with values ​​of 24-29, providing separate entries allows UEs to be multiplexed efficiently in one CDM group. In other words, multiplexing UEs in separate CDM groups makes it easier to ensure orthogonality than multiplexing multiple UEs in the same CDM group.

[0177] On the other hand, in a multi-TRP system, it is possible to use DMRS ports of different CDM groups. In a multi-TRP system, it is assumed that there will be differences in the received power from each TRP. Therefore, if the orthogonality between DMRS ports is lost (e.g., when frequency selectivity is strong), interference between a DMRS port of a TRP with relatively strong received power and a DMRS port of a TRP with relatively weak received power may result in performance degradation. Therefore, it is desirable for each TRP to use a DMRS port corresponding to a different CDM group.

[0178] An entry with a value of 11 in the antenna port field may be associated with DMRS without data, the number of CDM groups = 2, and DMRS ports = {0, 2}. This entry is useful regardless of whether single TRP or multi-TRP is used. For example, when this entry is selected, MU-MIMO is not applied (free DMRS ports are not used by other UEs), simplifying processing. Furthermore, other UEs cannot use free DMRS ports for a UE using this entry (antenna port). Therefore, the combination of DMRS ports = {8, 10} does not need to be specified in the entry with a value of 23 described below. In other words, the gNB can only specify either DMRS ports = {0, 2} or {8, 10}, and cannot simultaneously specify each DMRS port to different UEs.

[0179] An entry with a value of 23 in the antenna port field may be associated with the number of DMRS CDM groups without data = 2, and DMRS ports = {8, 10}, {9, 11}. For example, if DMRS ports = {0, 1, 8} are specified for UE #1 and DMRS ports = {2, 3, 10} are specified for another UE #2, DMRS ports = {9, 11} are simultaneously specified for another UE #3, thereby making it possible to effectively utilize the orthogonal DMRS ports to the maximum extent.

[0180] For example, in an entry with a value of 23 in the antenna port field, if the DMRS port is {8, 10} (e.g., in the case of 2+2=4 layers between two UEs), multiplexing with the DMRS port of another UE in the same CDM group is possible with {0, 2}, {1, 3}, or {9, 11}.

[0181] Also, in an entry with a value of 23 in the antenna port field, when the DMRS port is {9, 11} (for example, in the case of 3+3+2=8 layers between three UEs), multiplexing with the DMRS ports of other UEs in the same CDM group is possible, with {0, 1, 8} and {2, 3, 10}.

[0182] As mentioned above, the entry with a value of 23 in the antenna port field does not need to be included in the table.

[0183] For the DMRS port combinations per rank in the case of 2CW in embodiment 1.1 (right half of the table), at least one of the following combinations may be defined: - For rank 5, a combination of port index {0, 1, 2, 3, 8}; - For rank 6, a combination of port index {0, 1, 2, 3, 8, 10}; - For rank 7, a combination of port index {0, 1, 2, 3, 8, 9, 10}; - For rank 8, a combination of port index {0, 1, 2, 3, 8, 9, 10, 11}.

[0184] In addition, the DMRS port combinations for 1 CW in the first embodiment (left half of the table) may include combinations other than those in the above example, and at least one of the following combinations may be defined for each rank: - For rank 1, a combination of one index from port indexes {0, 1, 2, 3, 8, 9, 10, 11}; - For rank 2, a combination of two indexes from port indexes {0, 1, 2, 3, 8, 9, 10, 11}; - For rank 3, a combination of three indexes from port indexes {0, 1, 2, 3, 8, 9, 10, 11}; - For rank 4, a combination of four indexes from port indexes {0, 1, 2, 3, 8, 9, 10, 11}.

[0185] Here, the above-mentioned "port index {0, 1, 2, 3, 8, 9, 10, 11}" may be interchangeably read as "one of a first set (e.g., {0, 1, 2, 3}) and a second set (e.g., {8, 9, 10, 11})." The first / second set may be predetermined in a standard, configured in the UE by higher layer signaling, or determined based on UE capabilities. Which of the first and second sets an index is selected from may be specified in advance in a standard, configured in the UE by higher layer signaling, or determined based on UE capabilities.

[0186] 6A to 6C show variations of the antenna port table when the DMRS type is extended type 1 and the maximum DMRS length is 1. Fig. 7 shows another example of the antenna port table when the DMRS type is extended type 1 and the maximum DMRS length is 1.

[0187] For the single DCI-based multi-TRP case, a different antenna port table may be defined. For example, in the table of Fig. 5 described above, the entry with a value of 12 in the antenna port field may be defined (replaced) as shown in Fig. 6A. In Fig. 6A, the number of DMRS CDM groups without data = 2 may be associated with DMRS ports = {0, 2, 3}.

[0188] For example, in the entries of the antenna port field having a value (Value) of 9-11 in FIG. 5 described above, a combination of DMRS ports = {0, 1, 2} is supported. Therefore, it is possible to indicate 2 + 1 = 3 layers by two CDM groups. On the other hand, in the entry of the antenna port field having a value (Value) of 12, by supporting DMRS ports = {0, 2, 3}, it is possible to indicate 1 + 2 = 3 layers by two CDM groups.

[0189] Furthermore, in the table of Fig. 5 described above, entries with antenna port field values ​​(Value) = 30 and 31 may be defined (or added) as shown in Fig. 6B. In Fig. 6B, the entry with Value = 30 may associate the number of DMRS CDM groups without data = 2 with DMRS ports = {0, 2, 3}, and the entry with Value = 31 may associate the number of DMRS CDM groups without data = 2 with DMRS ports = {8, 10, 11}.

[0190] In the table of Fig. 5, the entry with Value = 9 supports the combination of DMRS port = {0, 1, 2}, and the entry with Value = 21 supports the combination of DMRS port = {8, 9, 10}. Therefore, it is possible to indicate 2 + 1 = 3 layers using two CDM groups. On the other hand, the entry with Value = 30 supports DMRS port = {0, 2, 3}, and the entry with Value = 31 supports DMRS port = {8, 10, 11}, so it is possible to indicate 1 + 2 = 3 layers using two CDM groups.

[0191] 5, entries with values ​​of 30 and 31 corresponding to one codeword and entries with values ​​of 4 and 5 corresponding to two codewords may be defined (added) as shown in Fig. 6C. The entries with values ​​of 30 and 31 corresponding to one codeword are the same as those in Fig. 6B, and therefore will not be described here.

[0192] In FIG. 6C , in an entry with Value=4 corresponding to two codewords, the number of DMRS CDM groups without data=2 may be associated with DMRS ports={0, 1, 2, 3, 10}, and in an entry with Value=5 corresponding to two codewords, the number of DMRS CDM groups without data=2 may be associated with DMRS ports={0, 1, 2, 3, 8, 10, 11}.

[0193] In the above-described Figure 5, combinations of rank 5 (3 + 2 = 5 layers), rank 6 (3 + 3 = 6 layers), rank 7 (4 + 3 = 7 layers), and rank 8 (4 + 4 = 8 layers) corresponding to two CDM groups are supported. According to the additional entry (Value = 4, 5) shown in Figure 6C, combinations of rank 5 (2 + 3 = 5 layers) and rank 7 (3 + 4 = 7 layers) can also be supported. Furthermore, combinations of rank 5 (4 + 1 / 1 + 4) and rank 6 (4 + 2 / 2 + 4) may also be supported.

[0194] FIG. 7 shows an example in which the row entry of FIG. 6C is added to the table of FIG.

[0195] [Embodiment 1.2] In embodiment 1.2, a case where DMRS type = extended type 1 and DMRS maximum length = 1 will be described. Note that in embodiment 1.2, content that may be the same as (or may be controlled / configured / adjusted in the same way as) embodiment 1.1 will not be described repeatedly. Figures 8 and 9 show an example of an antenna port table when DMRS type = extended type 1 and DMRS maximum length = 2.

[0196] Note that the antenna port table according to embodiment 1.2 is shown across two diagrams, Figures 8 and 9, due to the number of rows. That is, in this example, Figures 8 and 9 are defined as a single table. More specifically, the top row (Value = 43) of Figure 9 will be described as being immediately below the bottom row (Value = 42) of Figure 8. Also, as mentioned above, the tables shown in Figures 8 and 9 are merely examples, and separate tables may be defined according to the applicable scenario (single TRP / multiple TRP, or any of Categories 1 to 3).

[0197] First, the row entries of 1CW (left half of Fig. 8 and Fig. 9) will be described. In the antenna port table shown in this example, Value = 0-11 of 1CW may correspond to Value = 0-11 in Fig. 5 (Fig. 7). Value = 0-30 may correspond to Category 1, 31-61 may correspond to Category 2, and 62-67 may correspond to Category 3. Note that in Category 3, when there are a maximum of four ranks, only one CDM group may be used per UE.

[0198] Values ​​12-14 in Fig. 5 (Fig. 7) may correspond to Values ​​31-33 in this example. Values ​​21-22 in Fig. 5 (Fig. 7) may correspond to Values ​​40-41 in this example. Values ​​24-25 in Fig. 5 (Fig. 7) may correspond to Values ​​62-63 in this example.

[0199] In this example, entries with Value=12-30 (corresponding to FIG. 8) and 43-61 (corresponding to FIG. 9) are row entries newly added to FIG. 5. That is, the entries with Value=12-30 and 43-61 indicate cases where the number of front-loaded symbols is 2. For other Values, the number of front-loaded symbols may be 1.

[0200] In this example, Values ​​43-61 may be associated with DMRS without data, the number of CDM groups = 2, and the number of frontload symbols = 2. These row entries may indicate multiple DMRS ports using DMRS of length 2 within the same CDM group.

[0201] Values ​​= 0-2, 31-33, 62-63 are associated with DMRS without data and the number of CDM groups = 1, making it possible to reduce the overhead of DMRS.

[0202] Entries with values ​​of 9-10, 26-30, 40-41, 57-61 in brackets may not be specified (e.g., they may be deleted in the case of a single TRP) because values ​​of 62-67 corresponding to Category 3 are supported. When an entry is deleted, it can be indicated by the 6-bit antenna port field.

[0203] According to the entry with Value=42, it is possible to multiplex with DMRS ports={0,2}, {1,3}, or {9,11} of other UEs in the same CDM group (for example, in the case of 2+2=4 layers between two UEs). However, when DMRS ports={0,2} are indicated in Value=11, other DMRS ports are not used by other UEs. Therefore, the entry with Value=42 does not necessarily have to be specified (it may be deleted).

[0204] Next, the row entries of 2CW (the right half of FIG. 8) will be described. Values ​​= 0-4 in FIG. 5 may correspond to Values ​​= 4-7 in this example. Values ​​= 0-4, 8-23 in this example are newly added row entries. That is, entries with Values ​​= 0-4, 8-23 indicate a case where the number of front-loaded symbols is 2. On the other hand, entries with Values ​​= 4-7 indicate a case where the number of front-loaded symbols is 1.

[0205] In 2 CW, entries with Values ​​0-7, 12-23 may be associated with 2 DMRS CDM groups without data, while entries with Values ​​8-11 may be associated with 1 DMRS CDM group without data.

[0206] In 2CW, entries with values ​​0-3 correspond to ranks 5-8, respectively. Similarly, entries with values ​​8-11, 12-15, 16-19, and 20-23 may correspond to ranks 5-8, respectively.

[0207] In 2CW, entries with Value=8-19 allow the number of ports for each of a plurality of CDM groups to be distributed (mapped) evenly or so that the difference in the number of ports becomes small.

[0208] For example, when Value = 8 and DMRS ports = {0, 1, 4, 5, 8} are indicated, as shown in Figure 4A, in the two TDM CDM groups #0, the DMRS ports can be distributed to DMRS ports = {0, 1, 8} corresponding to TD-OCC #0 and DMRS ports = {4, 5} corresponding to TD-OCC #1.

[0209] In this way, the number of ports corresponding to a given UE is distributed equally or so that the difference between the numbers of ports is small among multiple TDM CDM groups (CDM groups having the same index). Note that in the example where Value=8, since the rank number is 5, which is an odd number, the number of ports may be distributed so that the difference between the numbers of ports is small among multiple TDM CDM groups. For example, if the rank number is 6, which is an even number, the number of ports may be distributed equally among multiple TDM CDM groups.

[0210] In this way, by specifying DMRS ports that are uniform or have a small difference in the number of ports, a performance improvement effect can be obtained during high-speed movement / high frequency selectivity (in cases where the above-mentioned near-far problem may occur). It is expected that the orthogonality of TD-OCC will be lost during high-speed movement. It is expected that the orthogonality of FD-OCC will be lost in channels with strong frequency selectivity. By specifying DMRS ports that are uniform or have a small difference in the number of ports, FD-OCC and TD-OCC can be applied uniformly. Furthermore, extreme performance degradation can be avoided in both cases of high-speed movement and channels with strong frequency selectivity. Furthermore, DMRS overhead can be reduced.

[0211] In 2CW, entries with Value=20-23 may not be defined (may be deleted).

[0212] Modification of [Embodiment 1.2] FIGS. 10A and 10B show variations of the antenna port table when DMRS type=extended type 1 and DMRS maximum length=2.

[0213] In the case where the DMRS type is Extended Type 1 and the maximum DMRS length is 2, for example, the entry with a value of 31 in the antenna port field in the table of Fig. 8 may be defined (replaced) as shown in Fig. 10A, where the number of DMRS CDM groups without data is 2 and the DMRS ports are {0, 2, 3} / {8, 9, 11}.

[0214] For example, in the entry of the antenna port field having a value of 9 or 40 in FIG. 7 described above, combinations of DMRS ports = {0, 1, 2} and {8, 9, 10} are supported. Therefore, it is possible to indicate 2 + 1 = 3 layers by two CDM groups. On the other hand, in the entry of the antenna port field having a value of 31, it is possible to indicate 1 + 2 = 3 layers by two CDM groups by supporting DMRS ports = {0, 2, 3} / {8, 9, 11}.

[0215] Furthermore, in the table of Figure 8 described above, entries with antenna port field values ​​(Value) = 68 and 69 as shown in Figure 10B may be defined (or added) for the case of single DCI-based multi-TRP. In Figure 10B, the entry with Value = 68 may associate the number of DMRS CDM groups without data = 2 with DMRS ports = {0, 2, 3}, and the entry with Value = 69 may associate the number of DMRS CDM groups without data = 2 with DMRS ports = {8, 10, 11}. As described above, by supporting DMRS ports = {0, 2, 3} / {8, 9, 11}, it is possible to indicate 1 + 2 = 3 layers using two CDM groups.

[0216] [Embodiment 1.3] In embodiment 1.3, a case will be described in which DMRS type = extended type 2 and DMRS maximum length = 1. Note that in embodiment 1.3, content that may be the same as (or may be controlled / configured / adjusted in the same way as) embodiments 1.1 / 1.2 will not be described repeatedly.

[0217] In the antenna port table of embodiment 1.3, the difference between the indexes of Category 1 DMRS ports and Category 2 DMRS ports may be, for example, +12, and the number of CDM groups without data may range from 1 to 3. That is, the offset indicator of Category 2 relative to Category 1 may be +12.

[0218] 11 and 12 show an example of an antenna port table when DMRS type = Extended Type 2 and DMRS maximum length = 1. Note that the antenna port table according to embodiment 1.3 is shown across two figures, FIG. 11 and FIG. 12, due to the number of rows. That is, in this example, FIG. 11 and FIG. 12 are combined and defined as a single table. More specifically, the top row (Value = 27) of FIG. 12 is described as being immediately below the bottom row (Value = 26) of FIG. 11. As mentioned above, the tables shown in FIG. 11 and FIG. 12 are merely examples, and separate tables may be defined according to the applicable scenario (single TRP / multi-TRP, or any of Categories 1 to 3).

[0219] First, the row entries of 1CW (left half of FIGS. 11 and 12) will be described. In the antenna port table shown in this example, Value=0-10 of 1CW may correspond to Value=0-10 in FIG.

[0220] Values ​​0-23 may correspond to Category 1, 24-47 may correspond to Category 2, and 48-59 may correspond to Category 3. Note that in Category 3, all combinations of the number of DMRS CDM groups without data = 1-3 may be covered, or some combinations may be omitted. For example, when the number of DMRS CDM groups without data = 1, a combination of DMRS ports for one CDM group may be specified, when the number of DMRS CDM groups without data = 2, a combination of DMRS ports for two CDM groups may be specified, and when the number of DMRS CDM groups without data = 3, a combination of DMRS ports for three CDM groups may be specified.

[0221] 5 may indicate entries corresponding to the following values ​​in this example: Entries indicated by [ ] may indicate antenna ports / DMRS ports spanning CDM groups corresponding to multiple TRPs.

[0222] Values ​​0-2 in Fig. 5 may correspond to Values ​​0-2 in this example. Values ​​12-14 in Fig. 5 may correspond to Values ​​24-26 in this example. Values ​​24-25 in Fig. 5 may correspond to Values ​​48-49 in this example.

[0223] Values ​​9-10 in Fig. 5 may correspond to Values ​​9-10 in this example, and Values ​​21-22 in Fig. 5 may correspond to Values ​​33-34 in this example.

[0224] Value=11 in Fig. 5 may correspond to Value=23 in this example. Value=23 in Fig. 5 may correspond to Value=47 in this example.

[0225] In this example, entries with Values ​​= 11-22 and 35-46 may be associated with the number of DMRS CDM groups without data = 3. The other Values ​​may be associated with the number of DMRS CDM groups without data = 1 / 2.

[0226] For example, if Value=23 is indicated in the existing specifications, Value=47 may be excluded (deleted) since MU-MIMO is not applied (other DMRS ports are not used for other UEs).

[0227] In addition, in the case of a single TRP, all or at least one of the entries with Value=9-10, 20-22, 33-34, and 44-46 may be deleted, thereby reducing the overhead of the DMRS.

[0228] Next, the row entries of 2CW (the right half of FIG. 11) will be described. In 2CW, Values ​​0-3 and 8-11 in this example may be associated with the number of DMRS CDM groups without data = 3. Also, Values ​​4-7 in this example may be associated with the number of DMRS CDM groups without data = 2. These row entries may be associated with ranks 5-8.

[0229] Either one of Value = 0-3 or 4-7 may be specified, or both may be specified. For example, in the case of Value = 0-3, by setting the number of DMRS CDM groups without data to 2, one CDM group can be FDMed with data using MU-MIMO, thereby improving UE throughput. On the other hand, in the case of Value = 4-7, by setting the number of DMRS CDM groups without data to 3, one CDM group can be assigned to another UE, thereby improving cell capacity.

[0230] In 2CW, entries with Value=4-11 allow the number of ports for each of a plurality of CDM groups to be distributed (mapped) evenly or so that the difference in the number of ports becomes small.

[0231] For example, when Value = 4 and DMRS ports = {0, 1, 2, 3, 12} are indicated, as shown in Figure 4B, in two FDM CDM groups #0 and #1, the DMRS ports can be distributed to DMRS ports = {0, 1, 12} and {2, 3} corresponding to TD-OCC #0, respectively.

[0232] In this way, the number of ports corresponding to a UE is distributed evenly or so that the difference between the numbers of ports is small among multiple TDM-DMed CDM groups (CDM groups having the same index). Note that in the example where Value=4, since the rank number is 5, which is an odd number, the number of ports may be distributed so that the difference between the numbers of ports is small (3 and 2) among multiple TDM-DMed CDM groups.

[0233] For example, when Value=5 and DMRS ports={0, 1, 2, 3, 12, 14} are specified, as shown in Fig. 4B, in two FDM CDM groups #0 and #1, the DMRS ports can be distributed to DMRS ports={0, 1, 12} and {2, 3, 14} corresponding to TD-OCC #0, respectively. In this way, when the rank number is 6, which is an even number, the number of ports in each of the multiple TDM CDM groups can be distributed evenly (three each).

[0234] Modification of [Embodiment 1.3] FIGS. 13A-13B show variations of the antenna port table when DMRS type=extended type 2 and DMRS maximum length=1.

[0235] In the case where the DMRS type is Extended Type 2 and the maximum DMRS length is 1, for example, the entry with a value of 24 in the antenna port field in the tables of Figures 11 and 12 may be defined (replaced) as shown in Figure 13A, where the number of DMRS CDM groups without data is 2 and the DMRS ports are {0, 2, 3} / {12, 14, 15}.

[0236] For example, in the entries of the antenna port field having values ​​(Value) = 9 and 33 in Figures 11 and 12 described above, combinations of DMRS ports = {0, 1, 2} and {12, 13, 14} are supported. Therefore, it is possible to indicate 2 + 1 = 3 layers by two CDM groups. On the other hand, in the entry of the antenna port field having value (Value) = 24, it is possible to indicate 1 + 2 = 3 layers by two CDM groups by supporting DMRS ports = {0, 2, 3} / {12, 14, 15}.

[0237] 11-12, entries with antenna port field values ​​(Value) = 60 and 61 as shown in FIG. 13B may be defined (or added) for the case of single DCI-based multi-TRP. In FIG. 13B, the entry with Value = 60 may associate the number of DMRS CDM groups without data = 2 with DMRS ports = {0, 2, 3}, and the entry with Value = 61 may associate the number of DMRS CDM groups without data = 2 with DMRS ports = {12, 14, 15}. As described above, by supporting DMRS ports = {0, 2, 3} / {12, 14, 15}, it is possible to indicate 1 + 2 = 3 layers using two CDM groups.

[0238] [Embodiment 1.4] In embodiment 1.4, a case will be described in which the DMRS type is extended type 2 and the maximum DMRS length is 2. Note that in embodiment 1.4, content that may be the same as (or may be controlled / configured / adjusted in the same way as) embodiments 1.1 / 1.2 / 1.3 will not be described repeatedly.

[0239] The antenna port table of embodiment 1.4 may include a DMRS port combination including only Category 2 DMRS ports. For example, the combination may correspond to a DMRS port combination obtained by adding +X (e.g., +12) to all indexes of at least one of the DMRS port combinations including only Category 1 DMRS ports.

[0240] 14-16 show an example of an antenna port table when the DMRS type is Extended Type 2 and the maximum DMRS length is 2. The antenna port table according to embodiment 1.3 is shown across three figures, Figures 14-16, due to the number of rows. That is, in this example, Figures 14-16 are defined as a single table, combining the three figures. More specifically, the top row (Value = 44) of Figure 15 is immediately below the bottom row (Value = 43) of Figure 14, and the top row (Value = 82) of Figure 16 is immediately below the bottom row (Value = 81) of Figure 15. As mentioned above, the tables shown in Figures 14-16 are merely examples, and separate tables may be defined depending on the applicable scenario (single TRP / multi-TRP, or any of Categories 1 to 3).

[0241] First, the row entries of 1CW (left half of FIGS. 14-16) will be described. In the antenna port table shown in this example, Value=0-10 of 1CW may correspond to Value=0-10 in FIG.

[0242] Values ​​0-57 may correspond to Category 1, 58-115 may correspond to Category 2, and 116-127 may correspond to Category 3. Note that in Category 3, all combinations of the number of DMRS CDM groups without data = 1-3 may be covered, or some combinations may be omitted. For example, when the number of DMRS CDM groups without data = 1, a combination of DMRS ports for one CDM group may be specified, when the number of DMRS CDM groups without data = 2, a combination of DMRS ports for two CDM groups may be specified, and when the number of DMRS CDM groups without data = 3, a combination of DMRS ports for three CDM groups may be specified.

[0243] 5 may indicate entries corresponding to the following values ​​in this example: Entries indicated by [ ] may indicate antenna ports / DMRS ports spanning CDM groups corresponding to multiple TRPs.

[0244] Values ​​0-2 in Fig. 5 may correspond to Values ​​0-2 in this example. Values ​​12-14 in Fig. 5 may correspond to Values ​​58-60 in this example. Values ​​24-25 in Fig. 5 may correspond to Values ​​116-117 in this example.

[0245] Values ​​9-10 in Fig. 5 may correspond to Values ​​9-10 in this example, and Values ​​21-22 in Fig. 5 may correspond to Values ​​67-68 in this example.

[0246] For example, if Value=23 is indicated in the existing specifications, Value=81 may be excluded (deleted) since MU-MIMO is not applied (other DMRS ports are not used for other UEs).

[0247] In addition, in the case of a single TRP, all or at least one of the entries with Value=9-10, 20-22, 42-47, 67-68, 78-80, and 100-105 may be deleted, thereby reducing the overhead of the DMRS.

[0248] Next, the row entries of 2CW (the right half of FIG. 14) will be described. In 2CW, in this example, Values ​​= 0-1, 10-13, 26, 37, 42-43 may be associated with the number of DMRS CDM groups without data = 3. Also, in this example, Values ​​= 2-9, 18-25, 38-41 may be associated with the number of DMRS CDM groups without data = 2. The other entries (Values ​​= 14-17) may be associated with the number of DMRS CDM groups without data = 1. All row entries of 2CW may be associated with ranks 5-8.

[0249] In 2CW, entries with Value=14-37 can reduce overhead in combining DMRS ports using one CDM group.

[0250] In 2CW, according to the entries of Value=6-13, 14-37, the number of ports for each of a plurality of CDM groups can be distributed (mapped) evenly or so that the difference in the number of ports becomes small.

[0251] For example, when Value = 7 and DMRS ports = {0, 1, 2, 3, 12, 14} are specified, as shown in Figure 4B, in the two FDM CDM groups #0 and #1, DMRS ports = {0, 1, 12} and {2, 3, 14} corresponding to TD-OCC #0 can be evenly distributed three by three.

[0252] For example, when Value = 15 and DMRS ports = {0, 1, 6, 7, 12, 18} are specified, as shown in Figure 4B, in the two TDM CDM groups #0, DMRS ports = {0, 1, 12} corresponding to TD-OCC #0 and DMRS ports = {6, 7, 18} corresponding to TD-OCC #1 can be evenly distributed three ports each.

[0253] For example, when Value = 23 and DMRS ports = {2, 3, 8, 9, 14, 20} are specified, as shown in Figure 4B, in the two TDM CDM groups #1, DMRS ports = {2, 3, 14} corresponding to TD-OCC #0 and DMRS ports = {8, 9, 20} corresponding to TD-OCC #1 can be evenly distributed three ports each.

[0254] In this way, when the rank number is an even number of 6, the number of ports in each of the multiple CDM groups to be TDMed may be distributed evenly (three each).

[0255] Also, for example, when Value = 14 and DMRS port = {0, 1, 6, 7, 12} is indicated, as shown in Figure 4B, in the two TDM CDM groups #0, they can be distributed to DMRS ports = {0, 1, 12} and {6, 7} corresponding to TD-OCC #0, respectively.

[0256] In this way, the number of ports corresponding to a UE is distributed evenly or so that the difference between the numbers of ports is small among multiple TDM-DMed CDM groups (CDM groups having the same index). Note that in the example where Value=14, since the rank number is 5, which is an odd number, the number of ports may be distributed so that the difference between the numbers of ports between multiple TDM-DMed CDM groups is small (3 and 2).

[0257] Furthermore, all or at least one of the entries with Value=38-43 may be deleted, thereby reducing the overhead of the DMRS.

[0258] Modification of [Embodiment 1.4] FIGS. 17A and 17B show variations of the antenna port table when DMRS type=extended type 2 and DMRS maximum length=2.

[0259] In the case where the DMRS type is Extended Type 2 and the maximum DMRS length is 2, for example, the entry with a value of 58 in the antenna port field in the tables of Figures 14-16 may be defined (replaced) as shown in Figure 17A. In Figure 17A, the number of DMRS CDM groups without data = 2 may be associated with DMRS ports = {0, 2, 3} / {12, 14, 15}.

[0260] For example, in the entries of Figures 14-16 described above with values ​​(Value) = 9 and 67 in the antenna port field, combinations of DMRS ports = {0, 1, 2} and {12, 13, 14} are supported. Therefore, it is possible to indicate 2 + 1 = 3 layers by two CDM groups. On the other hand, in the entry of value (Value) = 58 in the antenna port field, by supporting DMRS ports = {0, 2, 3} / {12, 14, 15}, it is possible to indicate 1 + 2 = 3 layers by two CDM groups.

[0261] Furthermore, in the tables of Figures 14 to 16 described above, entries with antenna port field values ​​(Value) = 128 and 129 as shown in Figure 17B may be defined (or added) for the case of single DCI-based multi-TRP. In Figure 17B, the entry with Value = 128 may associate the number of DMRS CDM groups without data = 2 with DMRS ports = {0, 2, 3}, and the entry with Value = 129 may associate the number of DMRS CDM groups without data = 2 with DMRS ports = {12, 14, 15}. As described above, by supporting DMRS ports = {0, 2, 3} / {12, 14, 15}, it is possible to indicate 1 + 2 = 3 layers using two CDM groups.

[0262] <Variations> In the first embodiment, as described in embodiments 1.1 to 1.4, the number of entries constituting the antenna port table and the antenna port field for indicating DMRS ports can be enormous. Therefore, the DMRS ports may be indicated based on other information in addition to the antenna port field.

[0263] For example, a DMRS port may be indicated using both the CDM group subset and the antenna port fields. Here, a CDM group subset may be a sub-component of a CDM group, and one CDM group may include multiple CDM group subsets. The CDM group subset may be configured in the UE by a higher layer parameter associated with the PDSCH / PUSCH (e.g., RRC signaling or MAC CE), or may be specified by the DCI that schedules the PDSCH / PUSCH. The CDM group subset may be identified by a CDM group subset ID.

[0264] For each group subset, the order of the CDM groups in the antenna port table may be reused. For example, if the antenna port table indicates a DMRS port index j for the first group subset, a table in which the DMRS port index j in the DMRS port table is replaced with j+P may be used for the second group subset. Here, P may be the number of DMRS ports in the group subset (the maximum number of DMRS ports in the group subset).

[0265] In the first embodiment, all of the categories 1, 2, and 3 may be defined in the antenna port table, or only some of them may be defined.

[0266] For example, reducing the size of the antenna port field may be configured in the UE by a higher layer parameter. By reducing the size of the antenna port field, a reduction in DCI overhead can be expected.

[0267] Note that, when a higher layer parameter indicating that the size of the antenna port field of the DCI is to be reduced compared to the Rel. 17 NR specifications is configured in the UE, a table in which one or more combinations of DMRS ports are selected from a specific antenna port table (e.g., an antenna port table when a higher layer parameter indicating that the size of the antenna port field of the DCI is to be increased compared to the Rel. 17 NR specifications is configured) based on an RRC configuration or a predetermined rule may be used.

[0268] Furthermore, rows that can be specified by DCI (e.g., DCI format 1_1 / 1_2) from the above-mentioned antenna port table may be specified / configured / restricted by RRC / MAC CE. Furthermore, a specific DMRS port may be specified based on different rules for DCI format 1_1 and DCI format 1_2. For example, DCI format 1_1 may specify rows that can be specified from the table, and DCI format 1_2 may specify rows that can be deleted / omitted. This makes it possible to reduce DCI overhead.

[0269] For example, DMRS ports may be indicated by a bitmap (one bit or multiple bits) of each row in the antenna port table, or by a subset obtained by grouping each row into a group subset (which may simply be referred to as grouping) as described above. The grouping rule may be determined in advance in a specification, or may be based on a predetermined number of rows in the table described above, a category, a number of ranks, or the number of DMRS CDM groups without data. Multiple rows may be grouped, and the DMRS ports that can be indicated may be indicated for each group using DCI. This makes it possible to reduce the overhead of RRC / MAC CE.

[0270] Furthermore, rows that can be indicated / configured / restricted using RRC / MAC CE may be limited to some rows in the table. That is, rows other than these limited rows may be indicated using DCI. Furthermore, rows that can be indicated by DCI for each of the above-mentioned subsets (groups consisting of multiple rows) may be indicated / configured / restricted using RRC / MAC CE.

[0271] According to the first embodiment described above, the UE can appropriately determine the Rel. 18 PDSCH DMRS port to be used.

[0272] Second Embodiment The second embodiment relates to MU-MIMO scheduling constraints.

[0273] For example, in Rel. 15, the following restrictions (constraints) are set for MU-MIMO scheduling:

[0274] For example, in the case of DMRS type = Type 1 / Type 2, if a UE is scheduled for 1 CW and assigned an antenna port mapping with a specific index in the existing antenna port table, or if a UE is scheduled for 2 CWs, the UE may assume that the remaining orthogonal antenna ports are not associated with transmitting PDSCH to another UE.

[0275] 18A-18B are diagrams showing an example of association of CDM groups, DMRS ports between multiple UEs, and OCCs when DMRS type = Type 1 / Type 2.

[0276] For example, existing specifications allow MU-MIMO based on existing DMRS port combinations, as shown in Figure 18A (Type 1) / Figure 18B (Type 2).

[0277] FIG. 18A shows an example in which two UEs (UE#0 / UE#1) corresponding to rank 1 are permitted MU-MIMO within the same CDM group.

[0278] 18B shows an example in which two UEs (UE#0 / UE#1) corresponding to rank 3 are permitted to use MU-MIMO between multiple CDM groups #0-2. Specifically, the DMRS port of UE#0 is mapped across CDM groups #0-1, and the DMRS port of UE#1 is mapped across CDM groups #1-2.

[0279] Thus, existing specifications allow MU-MIMO between different UEs within the same CDM group / across multiple CDM groups.

[0280] In the above-mentioned extended type case, it is not clear how to specify the MU-MIMO scheduling constraints.

[0281] Therefore, we have considered applying the MU-MIMO scheduling constraint to the above-mentioned extended type as well. Below, the MU-MIMO scheduling constraint will be explained using the above-mentioned antenna port tables as examples. Embodiments 2.1 to 2.4 shown below correspond to the above-mentioned embodiments 1.1 to 1.4, respectively.

[0282] 19A-19B are diagrams showing an example of association of CDM groups, DMRS ports between multiple UEs, and OCCs when DMRS type = Extended Type 1 / Extended Type 2.

[0283] For example, in Rel. 18 and later, four DMRS ports may exist in a CDM group. As shown in Figure 19A, four UEs (UEs #0-3) corresponding to rank 1 are preferably allowed MU-MIMO in one CDM group #0. Also, as shown in Figure 19B, two UEs (UEs #0-1) corresponding to rank 2 are preferably allowed MU-MIMO in one CDM group #0.

[0284] In this example, to support the above example, MU-MIMO scheduling constraints between multiple DMRS ports in Enhanced Type 1 / Enhanced Type 2 within one CDM group / among multiple CDM groups will be described.

[0285] For example, in the case of DMRS type = Enhanced Type 1 / Enhanced Type 2, if a UE is scheduled with 1 CW and assigned an antenna port mapping with a specific index in the new antenna port table (each of the antenna port tables mentioned above), the UE may assume that all remaining orthogonal antenna ports are not associated with transmitting PDSCH to another UE.

[0286] Here, a specific index in the new antenna port table may correspond to an entry of a row index indicated by a condition described later. That is, the above assumption made by the UE based on a certain condition may be interpreted as an MU-MIMO scheduling constraint.

[0287] Furthermore, the above-mentioned "all remaining orthogonal antenna ports" may refer to DMRS ports within the same CDM group (one CDM group), or may refer to DMRS ports within multiple CDM groups.

[0288] Also, in 2CW, MU-MIMO scheduling constraints may or may not be applied.

[0289] When applying DMRS type = Extended Type 1 / Extended Type 2, the UE may control the above scheduling constraints (whether to make the above assumptions) based on the type of extended type (Extended Type 1 / Extended Type 2), the maximum DMRS length (1 / 2), whether to apply single DCI-based multi-TRP, and the number of CWs (1CW / 2CW).

[0290] For example, in the rows (Values) where the following DMRS port combinations are indicated, the UE may assume that the remaining DMRS ports in the same CDM group / multiple CDM groups are not used by other UEs: All DMRS ports in a CDM group are already assigned to a certain UE (e.g., DMRS ports for Extension Type 1 = {0, 1, 8, 9}, DMRS ports for Extension Type 2 = {0, 1, 12, 13}). DMRS ports corresponding to 2CW (right side of each antenna port table (corresponding to ranks 5-8)). Three DMRS ports in a CDM group are assigned to a certain UE (e.g., DMRS ports for Extension Type 1 = {0, 1, 8}, DMRS ports for Extension Type 2 = {0, 1, 12}).

[0291] Each case will be described below in embodiments 2.1 to 2.4.

[0292] [Embodiment 2.1] In embodiment 2.1, a case where DMRS type=extended type 1 and DMRS maximum length=1 will be described.

[0293] In the antenna port tables shown in Figures 5-7 above, if at least one of the following rows (conditions 1-4) is indicated, the UE may apply the MU-MIMO scheduling constraint, i.e., the UE may assume that no other DMRS ports are assigned to other UEs.

[0294] <Condition 1> (Value=9, 10, 21, 22, 30, 31) These row indexes are examples in which 3 / 4 ports are assigned across two CDM groups.

[0295] <Condition 2> (Value = 11, 23) These row indexes are examples in which two ports are allocated across two CDM groups. In this case, the UE can estimate the channel without considering FD-OCC by knowing that MU-MIMO is not applied. In particular, in cases where frequency selectivity is strong, both the effect of reducing the UE processing load and the effect of improving performance (because FD-OCC is not actually used) can be expected.

[0296] <Condition 3> (Value = 24-29) These row indices are examples in which 3 / 4 ports are allocated in one CDM group. - If the above-mentioned "all remaining orthogonal antenna ports" refers to DMRS ports within the same CDM group (one CDM group), when 4 ports are allocated, additional multiplexing within the same CDM group is physically impossible. Therefore, this constraint is necessary. - If the above-mentioned "all remaining orthogonal antenna ports" refers to DMRS ports within multiple CDM groups, additional multiplexing within multiple CDM groups is possible. Therefore, this constraint may or may not be applied.

[0297] <Condition 4> (Value of 2CW (corresponding to the right half of the antenna port table) = 0-3) In the case of 2CW, allocating an available DMRS port to another UE may or may not be prohibited.

[0298] [Embodiment 2.2] In embodiment 2.2, a case will be described in which DMRS type = extended type 1 and DMRS maximum length = 2. Note that in embodiment 2.2, content that may be the same as (or may be controlled / configured / adjusted in the same way as) embodiment 2.1 will not be described repeatedly.

[0299] In the antenna port tables shown in Figures 8-10 above, if at least one of the following rows (conditions 1-4) is indicated, the UE may apply the MU-MIMO scheduling constraint, i.e., the UE may assume that no other DMRS ports are assigned to other UEs:

[0300] <Condition 1> (Value=9, 10, 26-30, 40-41, 57-61, 68, 69) These row indexes are examples in which 3 / 4 ports are assigned across two CDM groups.

[0301] <Condition 2> (Value = 11, 42) These row indices are examples in which two ports are allocated across two CDM groups. In this case, the UE can estimate the channel without considering FD-OCC by knowing that MU-MIMO is not applied. In particular, in cases where frequency selectivity is strong, both the effect of reducing the UE processing load and the effect of improving performance (because FD-OCC is not actually used) can be expected.

[0302] <Condition 3> (Value = 62-67) These row indices are examples in which 3 / 4 ports are allocated in one CDM group. - If the above-mentioned "all remaining orthogonal antenna ports" refers to DMRS ports within the same CDM group (one CDM group), when 4 ports are allocated, additional multiplexing within the same CDM group is physically impossible. Therefore, this constraint is necessary. - If the above-mentioned "all remaining orthogonal antenna ports" refers to DMRS ports within multiple CDM groups, additional multiplexing within multiple CDM groups is possible. Therefore, this constraint may or may not be applied.

[0303] <Condition 4> (Value of 2CW (corresponding to the right half of the antenna port table) = 0-23) In the case of 2CW, allocating an available DMRS port to another UE may or may not be prohibited.

[0304] [Embodiment 2.3] In embodiment 2.3, a case will be described in which DMRS type = extended type 2 and DMRS maximum length = 1. Note that in embodiment 2.3, content that may be the same as (or may be controlled / configured / adjusted in the same way as) embodiments 2.1-2.2 will not be described repeatedly.

[0305] In the antenna port tables shown in Figures 11-13 above, if at least one of the following rows (conditions 1-4) is indicated, the UE may apply the MU-MIMO scheduling constraint, i.e., the UE may assume that no other DMRS ports are assigned to other UEs:

[0306] <Condition 1> (Value=9, 10, 20-22, 33-34, 44-46, 60, 61) These row indices are examples in which 3 / 4 ports are assigned across two CDM groups. Note that Value=10 and 34 may be excluded from this constraint.

[0307] <Condition 2> (Value = 23, 47) These row indices are examples in which two ports are allocated across two CDM groups. In this case, the UE knows that MU-MIMO is not applied, and can perform channel estimation without considering FD-OCC. In particular, in cases where frequency selectivity is strong, both the effect of reducing the UE processing load and the effect of improving performance (because FD-OCC is not actually used) can be expected.

[0308] <Condition 3> (Value = 48-59) These row indices are examples in which 3 / 4 ports are allocated in one CDM group. - If the above-mentioned "all remaining orthogonal antenna ports" refers to DMRS ports within the same CDM group (one CDM group), when 4 ports are allocated, additional multiplexing within the same CDM group is physically impossible. Therefore, this constraint is necessary. - If the above-mentioned "all remaining orthogonal antenna ports" refers to DMRS ports within multiple CDM groups, additional multiplexing within multiple CDM groups is possible. Therefore, this constraint may or may not be applied.

[0309] <Condition 4> (Value of 2CW (corresponding to the right half of the antenna port table) = 0-11) In the case of 2CW, allocation of an available DMRS port to another UE may or may not be prohibited.

[0310] [Embodiment 2.4] In embodiment 2.4, a case will be described in which DMRS type = extended type 2 and DMRS maximum length = 2. Note that in embodiment 2.4, content that may be the same as (or may be controlled / configured / adjusted in the same way as) embodiments 2.1 to 2.3 will not be described repeatedly.

[0311] In the antenna port tables shown in Figures 14-17 above, if at least one of the following rows (conditions 1-4) is indicated, the UE may apply the MU-MIMO scheduling constraint, i.e., the UE may assume that no other DMRS ports are assigned to other UEs:

[0312] <Condition 1> (Value=9, 10, 20-22, 42-47, 67-68, 78-80, 100-105, 128-129) These row indices are examples in which 3 / 4 ports are assigned across two CDM groups. Note that Value=10 may be excluded from this constraint.

[0313] <Condition 2> (Value = 23, 81) These row indices are an example in which two ports are allocated across two CDM groups. In this case, the UE knows that MU-MIMO is not applied, and can perform channel estimation without considering FD-OCC. In particular, in cases where frequency selectivity is strong, both the effect of reducing the UE processing load and the effect of improving performance (because FD-OCC is not actually used) can be expected.

[0314] <Condition 3> (Value = 116-127) These row indices are an example in which 3 / 4 ports are allocated in one CDM group. - If the above-mentioned "all remaining orthogonal antenna ports" refers to DMRS ports within the same CDM group (one CDM group), when 4 ports are allocated, additional multiplexing within the same CDM group is physically impossible. Therefore, this constraint is necessary. - If the above-mentioned "all remaining orthogonal antenna ports" refers to DMRS ports within multiple CDM groups, additional multiplexing within multiple CDM groups is possible. Therefore, this constraint may or may not be applied.

[0315] <Condition 4> (Value of 2CW (corresponding to the right half of the antenna port table) = 0-43) In the case of 2CW, allocating an available DMRS port to another UE may or may not be prohibited.

[0316] <Variation 1> As described in the above embodiments, when 2CW is instructed, the above constraint may or may not be applied.

[0317] Furthermore, the above constraint may be applied to a CDM group to which a DMRS port corresponding to 2 CWs is mapped. On the other hand, the above constraint may not be applied to another CDM group (a CDM group to which a DMRS port corresponding to 2 CWs is not mapped). For example, this case applies to a row associated with three DMRS CDM groups without data when two CDM groups are applied in Extended Type 2.

[0318] In addition, the maximum number of UEs that can be multiplexed in MU-MIMO may be limited depending on the total number of MIMO layers that the UE can process. For example, if a maximum of four layers is specified and three DMRS ports are specified for a UE, it may be permitted to assign one additional DMRS port to another UE in the same or a different CDM group. In this case, it may not be permitted to assign two or more additional DMRS ports to another UE in the same or a different CDM group.

[0319] This is because it is assumed that there is a limit to the MIMO order (number of layers) that the UE processes when receiving PDSCH using MU-MIMO. The total number of MIMO layers that the UE can process may be specified in the specifications, configured in a higher layer, or reported in the UE capabilities. These values ​​may be configured / specified / reported for each BWP / CC / Band / Frequency range.

[0320] <Variation 2> FIG. 20 shows a variation of the antenna port table when the DMRS type is extended type 1 and the maximum DMRS length is 1.

[0321] For example, even if the same DMRS port combination is indicated in an antenna port table for a single DCI-based multi-TRP and in other antenna port tables, the applicability of MU-MIMO scheduling constraints may differ. For example, an example will be described in the antenna port table shown in Figure 20. Each row entry shown in Figure 20 represents an example useful when applying a single-based multi-TRP.

[0322] In Figure 20, Value = 9 corresponds to 2 + 1 = 3 layers, Value = 10 corresponds to 2 + 2 = 4 layers, Value = 11 corresponds to 1 + 1 = 2 layers, Value = 21 corresponds to 2 + 1 = 3 layers, Value = 22 corresponds to 2 + 2 = 4 layers, Value = 30 corresponds to 1 + 2 = 3 layers, and Value = 31 corresponds to 1 + 2 = 3 layers. Note that Value = 30 and 31 may be row entries that are applied only to the single DCI-based multi-TRP case, as described above.

[0323] In this way, in the case of a single DCI-based multi-TRP, in order to avoid the above-mentioned near-far problem (e.g., performance degradation of a certain CDM group caused by differences in received power between multiple TRPs), DMRS ports are assigned so that each TRP uses a different CDM group. Therefore, it is preferable not to apply MU-MIMO even for the same CDM group. This is because the above-mentioned near-far problem may occur if DMRS ports of the same CDM group are transmitted from different TRPs between UEs. Therefore, in the case of a single DCI-based multi-TRP, when the row entries shown in Figure 20 are indicated, the above constraints may be applied.

[0324] On the other hand, when a single DCI-based multi-TRP is not applied (especially in the case of a single TRP), the above-mentioned near-far problem between DMRSs does not occur. Therefore, even if different UEs are multiplexed into the same CDM group, the impact is considered to be small. Therefore, when a single DCI-based multi-TRP is not applied, if the row entry shown in Figure 20 is indicated, the above constraint may not be applied.

[0325] For example, in the case of Value=11 in Fig. 20, applying the MU-MIMO scheduling constraint regardless of the multi-TRP is considered to be beneficial in terms of characteristics and UE processing load. Therefore, the constraint may be applied.

[0326] According to the second embodiment described above, the UE can appropriately control the application of MU-MIMO operation.

[0327] <Supplementary Information> [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.

[0328] 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.

[0329] 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.

[0330] Furthermore, notification of any information to the UE in the above embodiments may be performed periodically, semi-persistently, or aperiodically.

[0331] [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.

[0332] 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.

[0333] If the notification is made by UCI, the notification may be transmitted using PUCCH or PUSCH.

[0334] Furthermore, any information in the above-described embodiments may be notified from the UE periodically, semi-persistently, or aperiodically.

[0335] [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.

[0336] At least one of the above-described embodiments may be applied only to UEs that have reported or support a particular UE capability.

[0337] The specific UE capability may indicate at least one of the following: Supporting specific processing / operation / control / information for at least one of the above embodiments. Supporting a greater number of DMRS ports for PDSCH / PUSCH than in existing specifications. Supporting a greater number of DMRS ports for PDSCH / PUSCH DMRS using TD-OCC / FD-OCC / FDM than in existing specifications. Supporting FD OCC of length 4 / 6. Supporting Category 1 / 2 / 3 (Category 1 / 2 / 3 DMRS ports, Category 1 / 2 / 3 DMRS port combinations). Supporting MU-MIMO restrictions.

[0338] 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).

[0339] 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)).

[0340] Furthermore, at least one of the above-described embodiments may be applied when specific information related to the above-described embodiments (or performing the operations of the above-described embodiments) is configured / activated / triggered in the UE by higher layer signaling / physical layer signaling. For example, the specific information may be information indicating that the functions of the respective embodiments are enabled, any RRC parameters for a specific release (e.g., Rel. 18 / 19), etc.

[0341] 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.

[0342] (Supplementary Notes) The following inventions are supplemented with respect to one embodiment of the present disclosure. [Supplementary Note 1] A terminal, comprising: a receiver that, when supporting a combination of Category 1 Demodulation Reference Signal (DMRS) ports and Category 2 DMRS ports in at least one Code Division Multiplexing (CDM) group, receives Downlink Control Information (DCI) indicating the combination and scheduling a shared channel for one or two codewords; and a controller that controls transmission or reception of the shared channel based on the combination, wherein the combination further includes a combination of Category 3 DMRS ports and includes an entry indicating at least one of a DMRS port spanning the CDM group and a DMRS port corresponding to a plurality of transmission / reception points. [Supplementary Note 2] The terminal according to Supplementary Note 1, wherein the combination includes a plurality of DMRS ports for each of a plurality of CDM groups. [Supplementary Note 3] The terminal according to Supplementary Note 1 or Supplementary Note 2, wherein the combinations are distributed so that the numbers of DMRS ports are equal or have small differences for each of a plurality of CDM groups corresponding to two codewords. [Supplementary Note 4] The terminal according to any one of Supplementary Note 1 to Supplementary Note 3, wherein the combination is defined for each DMRS type or each DMRS maximum length.

[0343] (Supplementary Notes) The following inventions are supplementary notes regarding one embodiment of the present disclosure. [Supplementary Note 1] A terminal comprising: a receiver unit that, when supporting a combination of Category 1 Demodulation Reference Signal (DMRS) ports and Category 2 DMRS ports in at least one Code Division Multiplexing (CDM) group, receives Downlink Control Information (DCI) indicating the combination and scheduling a shared channel for one or two codewords; and a controller that controls transmission or reception of the shared channel based on the combination, wherein the combination includes an entry indicating at least one of a DMRS port spanning the CDM group and a DMRS port corresponding to a plurality of transmission and reception points, and the controller controls a Multi User Multiple Input Multiple Output (MU-MIMO) scheduling constraint when assigned a specific DMRS port mapping based on the combination. [Supplementary Note 2] The terminal according to Supplementary Note 1, wherein the scheduling constraint is to assume that orthogonal antenna ports in a CDM group are not associated with transmission of the shared channel to another terminal. [Supplementary Note 3] The terminal according to Supplementary Note 1 or Supplementary Note 2, wherein the controller controls the scheduling constraint based on any of a DMRS type, a DMRS maximum length, application of a single DCI-based multiple transmission / reception point (TRP), and a codeword number. [Supplementary Note 4] The terminal according to any of Supplementary Notes 1 to 3, wherein the controller does not apply the scheduling constraint on a specific DMRS port or another DMRS port when the specific DMRS port is configured.

[0344] (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.

[0345] 21 is a diagram illustrating 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) or 5th generation mobile communication system New Radio (5G NR) specified by the Third Generation Partnership Project (3GPP).

[0346] 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.

[0347] 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.

[0348] 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))).

[0349] 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.

[0350] 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).

[0351] 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.

[0352] 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.

[0353] 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.

[0354] 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.

[0355] 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.

[0356] The user terminal 20 may be a terminal that supports at least one of communication methods such as LTE, LTE-A, and 5G.

[0357] 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).

[0358] 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.

[0359] 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.

[0360] 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.

[0361] 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).

[0362] 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.

[0363] 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.

[0364] 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.

[0365] 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.

[0366] 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.

[0367] 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.

[0368] 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.

[0369] 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.

[0370] 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).

[0371] 22 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.

[0372] 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.

[0373] 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.

[0374] 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.

[0375] 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.

[0376] 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.

[0377] 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.

[0378] 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.

[0379] 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.

[0380] 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.

[0381] 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.

[0382] 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.

[0383] On the other hand, the transmitting / receiving unit 120 (RF unit 122) may perform amplification, filtering, demodulation to a baseband signal, etc. on the radio frequency band signal received by the transmitting / receiving antenna 130.

[0384] 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.

[0385] 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.

[0386] 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.

[0387] 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.

[0388] The transceiver 120 may transmit Downlink Control Information (DCI) to the user terminal 20 indicating a combination of Category 1 Demodulation Reference Signal (DMRS) ports and Category 2 DMRS ports in at least one Code Division Multiplexing (CDM) group, if the user terminal 20 supports the combination, and scheduling a shared channel for one or two codewords.

[0389] The control unit 110 may control reception or transmission of the shared channel. When a specific DMRS port mapping is assigned based on the combination, the control unit 110 may control a scheduling constraint for multi-user multiple input multiple output (MU-MIMO). The scheduling constraint is to assume that orthogonal antenna ports in a CDM group are not associated with transmitting the shared channel to another terminal. The control unit 110 may control the scheduling constraint based on any of a DMRS type, a maximum DMRS length, application of a single DCI-based multiple transmission / reception point (TRP), and the number of codewords. When a specific DMRS port is configured, the control unit 110 does not apply the scheduling constraint on the DMRS port or another DMRS port.

[0390] (User terminal) Fig. 23 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.

[0391] 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.

[0392] 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.

[0393] 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.

[0394] 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.

[0395] 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.

[0396] 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.

[0397] 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.

[0398] 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.

[0399] 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.

[0400] 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.

[0401] 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.

[0402] 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.

[0403] 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.

[0404] 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.

[0405] 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.

[0406] The measurement unit 223 may derive channel measurements for CSI calculation based on the channel measurement resources. The channel measurement resources may be, for example, non-zero power (NZP) CSI-RS resources. The measurement unit 223 may also derive interference measurements for CSI calculation based on the interference measurement resources. The interference measurement resources may be at least one of an NZP CSI-RS resource for interference measurement, a CSI-Interference Measurement (IM) resource, etc. Note that CSI-IM may be referred to as CSI-Interference Management (IM) or may be interchangeably read as Zero Power (ZP) CSI-RS. Note that in the present disclosure, CSI-RS, NZP CSI-RS, ZP CSI-RS, CSI-IM, CSI-SSB, etc. may be interchangeably read as interchangeable.

[0407] 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.

[0408] When the transceiver 220 supports a combination of Category 1 Demodulation Reference Signal (DMRS) ports and Category 2 DMRS ports in at least one Code Division Multiplexing (CDM) group, the transceiver 220 may receive Downlink Control Information (DCI) indicating the combination and scheduling a shared channel (e.g., PDSCH / PUSCH) for one or two codewords. The controller 210 may control transmission or reception of the shared channel based on the combination. The combinations may further include a combination of Category 3 DMRS ports, and may include entries indicating at least one of a DMRS port spanning the CDM group and a DMRS port corresponding to multiple transmission / reception points. The combinations include multiple DMRS ports for multiple CDM groups. The combinations are distributed so that the number of DMRS ports is equal or has a small difference between them for multiple CDM groups corresponding to two codewords. The combinations are defined for each DMRS type or maximum DMRS length.

[0409] When a specific DMRS port mapping is assigned based on the combination, the control unit 210 may control a scheduling constraint for multi-user multiple input multiple output (MU-MIMO). The scheduling constraint is to assume that orthogonal antenna ports in a CDM group are not associated with transmitting the shared channel to another terminal. The control unit 210 may control the scheduling constraint based on any of the DMRS type, the maximum DMRS length, the application of a single DCI-based multiple transmit / receive point (TRP), and the number of codewords. When a specific DMRS port is configured, the control unit 210 does not apply the scheduling constraint on the DMRS port or another DMRS port.

[0410] (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.

[0411] 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.

[0412] 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. Fig. 24 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.

[0413] 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.

[0414] 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.

[0415] 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.

[0416] 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.

[0417] 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.

[0418] 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.

[0419] 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.

[0420] 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.

[0421] 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).

[0422] 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.

[0423] 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.

[0424] (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.

[0425] 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.

[0426] 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.

[0427] 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.

[0428] 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.

[0429] 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.

[0430] 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.

[0431] 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.

[0432] 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.

[0433] 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.

[0434] 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.

[0435] 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.

[0436] 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.

[0437] 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.

[0438] 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.

[0439] 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.

[0440] 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.

[0441] 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.

[0442] 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."

[0443] 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.

[0444] 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.

[0445] 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.

[0446] 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.

[0447] 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.

[0448] 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.

[0449] 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.

[0450] 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).

[0451] 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).

[0452] 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).

[0453] 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.

[0454] 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.

[0455] 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).

[0456] In this 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," "layer," "number of layers," "rank," "resource," "resource set," "beam," "beam width," "beam angle," "antenna," "antenna element," "panel," "UE panel," "transmitting entity," "receiving entity," etc. may be used interchangeably.

[0457] In the present disclosure, the term "antenna port" may be interchangeably read as an antenna port for any signal / channel (e.g., a demodulation reference signal (DMRS) port). In the present disclosure, the term "resource" may be interchangeably read as a resource for any signal / channel (e.g., a reference signal resource, an SRS resource, etc.). The resource may include time / frequency / code / space / power resources. Furthermore, the spatial domain transmission filter may include at least one of a spatial domain transmission filter and a spatial domain reception filter.

[0458] The group may include, for example, at least one of a spatial relationship group, a Code Division Multiplexing (CDM) group, a Reference Signal (RS) group, a Control Resource Set (CORESET) group, a PUCCH group, an antenna port group (e.g., a DMRS port group), a layer group, a resource group, a beam group, an antenna group, a panel group, and the like.

[0459] In addition, in the present disclosure, beam, SRS Resource Indicator (SRI), CORESET, CORESET pool, PDSCH, PUSCH, codeword (CW), transport block (TB), RS, etc. may be read as interchangeable terms.

[0460] In addition, in the present disclosure, the terms TCI state, downlink TCI state (DL TCI state), uplink TCI state (UL TCI state), unified TCI state, common TCI state, joint TCI state, etc. may be read interchangeably.

[0461] Furthermore, in the present disclosure, terms such as "QCL," "QCL assumption," "QCL relationship," "QCL type information," "QCL property / properties," "specific QCL type (e.g., Type A, Type D) property," and "specific QCL type (e.g., Type A, Type D)" may be interchangeable.

[0462] In the present disclosure, terms such as index, identifier (ID), indicator, indication, and resource ID may be interchangeable. In the present disclosure, terms such as sequence, list, set, group, cluster, and subset may be interchangeable.

[0463] Furthermore, the spatial relationship information identifier (ID) (TCI state ID) and the spatial relationship information (TCI state) may be interchangeable. The "spatial relationship information (TCI state)" may be interchangeable with "set of spatial relationship information (TCI state)", "one or more pieces of spatial relationship information", etc. The TCI state and the TCI may be interchangeable. The spatial relationship information and the spatial relationship may be interchangeable.

[0464] 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.

[0465] 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.

[0466] 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.

[0467] In this disclosure, the terms "Mobile Station (MS)," "user terminal," "User Equipment (UE)," "terminal," etc. may be used interchangeably.

[0468] 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.

[0469] 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.

[0470] 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.

[0471] 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.

[0472] 25 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.

[0473] 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.

[0474] 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).

[0475] 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.

[0476] 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.

[0477] 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.

[0478] 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.

[0479] 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.

[0480] 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).

[0481] 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.

[0482] 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)).

[0483] 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.

[0484] 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.

[0485] 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.

[0486] 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.

[0487] 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.

[0488] 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).

[0489] 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."

[0490] 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.

[0491] 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.

[0492] 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.

[0493] Furthermore, "determination" may be considered to be "determining" resolving, selecting, choosing, establishing, comparing, etc. In other words, "determination" may be considered to be "determining" some kind of action. In the present disclosure, "determination" may be read interchangeably with the above-mentioned actions.

[0494] Furthermore, in this disclosure, "determine / determining" may be interchangeably read as "assume / assuming," "expect / expecting," "consider / considering," etc. Furthermore, in this disclosure, "does not expect to do..." may be interchangeably read as "assumes not to do...."

[0495] In the present disclosure, "expect" may be interchangeably read as "be expected." For example, "expect(s) ..." ("..." may be expressed, for example, as a that clause, a to-infinitive, etc.) may be interchangeably read as "be expected ...." "does not expect ..." may be interchangeably read as "be not expected ...." Furthermore, "An apparatus A is not expected ..." may be interchangeably read as "an apparatus B other than apparatus A does not expect ... from apparatus A" (e.g., if apparatus A is a UE, apparatus B may be a base station).

[0496] 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.

[0497] 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."

[0498] 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.

[0499] 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."

[0500] 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.

[0501] 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.

[0502] 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").

[0503] In this disclosure, the terms "of," "for," "regarding," "related to," "associated with," etc. may be read interchangeably.

[0504] In the present disclosure, terms such as "when A, B," "if A, (then) B," "B upon A," "B in response to A," "B based on A," "B during / while A," "B before A," "B at (the same time as) / on A," "B after A," "B since A," and "B until A" may be interchangeable. Note that A, B, and the like herein may be replaced with appropriate expressions such as nouns, gerunds, and regular sentences, depending on the context. Note that the time difference between A and B may be approximately zero (immediately after or immediately before). A time offset may also be applied to the time at which A occurs. For example, "A" may be interchangeable with "before / after a time offset at which A occurs." The time offset (eg, one or more symbols / slots) may be predefined or may be specified by the UE based on signaled information.

[0505] In the present disclosure, timing, time, duration, time instance, any time unit (e.g., slot, subslot, symbol, subframe), period, occasion, resource, etc. may be read interchangeably.

[0506] 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 description of the present disclosure is for illustrative purposes only and does not impose any limiting meaning on the invention according to the present disclosure.

Claims

1. A receiver for receiving downlink control information (DCI) indicating a demodulation reference signal (DMRS) port combination and scheduling a downlink shared channel (PDSCH) for one or two codewords; A control unit that controls reception of the PDSCH based on the combination when a DMRS extension type is set, The combination includes entries indicating DMRS ports across multiple code division multiplexing (CDM) groups, and the number of DMRS ports is distributed evenly or with a small difference between the number of DMRS ports among the multiple CDM groups corresponding to two codewords; If a PDSCH for one codeword is scheduled and a specific DMRS port mapping is assigned based on the combination, or if a PDSCH for two codewords is scheduled, the control unit assumes that the remaining orthogonal DMRS ports are not associated with transmitting the PDSCH to another terminal.

2. Receiving downlink control information (DCI) indicating a demodulation reference signal (DMRS) port combination and scheduling a downlink shared channel (PDSCH) for one or two codewords; If a DMRS extension type is configured, controlling reception of the PDSCH based on the combination; The combination includes entries indicating DMRS ports across multiple code division multiplexing (CDM) groups, and the number of DMRS ports is distributed evenly or with a small difference between the number of DMRS ports among the multiple CDM groups corresponding to two codewords; A wireless communication method for a terminal, wherein when a PDSCH for one codeword is scheduled and a specific DMRS port mapping is assigned based on the combination, or when PDSCHs for two codewords are scheduled, the terminal assumes that the remaining orthogonal DMRS ports are not associated with transmitting the PDSCH to another terminal.

3. A transmitter that transmits downlink control information (DCI) indicating a demodulation reference signal (DMRS) port combination and scheduling a downlink shared channel (PDSCH) for one or two codewords; A control unit that controls transmission of the PDSCH based on the combination when a DMRS extension type is set, The combination includes entries indicating DMRS ports across multiple code division multiplexing (CDM) groups, and the number of DMRS ports is distributed evenly or with a small difference between the number of DMRS ports among the multiple CDM groups corresponding to two codewords; A base station, wherein when a PDSCH for one codeword is scheduled and a specific DMRS port mapping is assigned based on the combination, or when a PDSCH for two codewords is scheduled, the remaining orthogonal DMRS port is not associated with transmitting the PDSCH to another terminal.

4. A system having a terminal and a base station, The terminal a receiver for receiving downlink control information (DCI) indicating a demodulation reference signal (DMRS) port combination and scheduling a downlink shared channel (PDSCH) for one or two codewords; A control unit that controls reception of the PDSCH based on the combination when a DMRS extension type is set, The combination includes entries indicating DMRS ports across multiple code division multiplexing (CDM) groups, and the number of DMRS ports is distributed evenly or with a small difference between the number of DMRS ports among the multiple CDM groups corresponding to two codewords; When a PDSCH for one codeword is scheduled and a specific DMRS port mapping is assigned based on the combination, or when a PDSCH for two codewords is scheduled, the control unit assumes that the remaining orthogonal DMRS ports are not associated with transmitting the PDSCH to another terminal; The base station A system comprising a transmitter that transmits the DCI.