Terminal, wireless communication method, base station and system

Abstract

A terminal according to one embodiment of the present disclosure comprises: a reception unit that receives a demodulation reference signal (DMRS) configuration; and a control unit that, on the basis of said configuration and at least one association between a plurality of code division multiplexing (CDM) groups and a plurality of DMRS ports, controls the transmission and reception of the DMRS. The number of the plurality of CDM groups for a DMRS configuration type 1 is greater than 2, and the number of the plurality of CDM groups for a DMRS configuration type 2 is greater than 3. With this embodiment of the present disclosure, it is possible to use a suitable number of DMRS ports.

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) 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] In future wireless communication systems (e.g., NR), a beam management technique is being introduced. For example, in NR, it is being considered to form (or use) a beam in at least one of a base station and a user terminal (user equipment (UE)).

[0006] On the other hand, for orthogonalizing layers, a reference signal of multiple ports (for example, a demodulation reference signal (DMRS)) is used. In future wireless communication systems, it is required to increase the number of DMRS ports compared to the existing specifications. However, how to increase the number of DMRS ports has not yet been studied. If an appropriate number of DMRS ports cannot be used, there is a risk that communication throughput / communication quality will deteriorate.

[0007] Therefore, one of the objects of the present disclosure is to provide a terminal, a wireless communication method, and a base station that use an appropriate number of DMRS ports.

[0008] A terminal according to one aspect of the present disclosure has a receiving unit that receives a demodulation reference signal (DMRS) configuration, and a control unit that controls transmission and reception of the DMRS based on one or more associations between a plurality of code division multiplexing (CDM) groups and a plurality of DMRS ports and the configuration, wherein the number of the plurality of CDM groups for DMRS configuration type 1 is greater than two, and the number of the plurality of CDM groups for DMRS configuration type 2 is greater than three.

[0009] According to one aspect of the present disclosure, any suitable number of DMRS ports may be used.

[0010] FIG. 1 shows example parameters for PDSCH DMRS configuration type 1. FIG. 2 shows example parameters for PUSCH DMRS configuration type 1. FIG. 3 shows an example of a new DMRS port table for increasing the number of DMRS ports. FIG. 4 shows another example of a new DMRS port table for increasing the number of DMRS ports. FIG. 5 shows an example of a new DMRS port table for DMRS configuration type 1 according to option 1 of option 1. FIG. 6 shows an example of a new DMRS port table for DMRS configuration type 2 according to option 1 of option 1. FIG. 7 shows an example of a new DMRS port table for DMRS configuration type 1 according to option 2 of option 1. FIG. 8 shows an example of a new DMRS port table for DMRS configuration type 2 according to option 2 of option 1. FIG. 9 shows an example of a new DMRS port table for case 1 of option 2. FIG. 10 shows an example of a new DMRS port table for case 3 of option 2. FIG. 11 shows an example of a pseudo-random sequence generator for generating DMRS sequences. Figure 12 shows an example of a CDM group list for Case 1. Figure 13 shows an example of a CDM group list for Case 2. Figure 14 shows an example of a CDM group list for Case 3. Figure 15 shows an example of a CDM group list for Case 4. Figure 16 shows an example of a DMRS configuration. Figure 17 shows an example of an existing antenna port table for DMRS configuration type 1, DMRS maximum length = 1. Figure 18 shows a first example of an existing antenna port table for DMRS configuration type 1, DMRS maximum length = 2. Figure 19 shows a second example of an existing antenna port table for DMRS configuration type 1, DMRS maximum length = 2. Figure 20 shows a first example of an existing antenna port table for DMRS configuration type 2, DMRS maximum length = 1. Figure 21 shows a second example of an existing antenna port table for DMRS configuration type 2, DMRS maximum length = 1. Figure 22 shows a first example of an existing antenna port table for DMRS configuration type 2, DMRS maximum length = 2. FIG. 23 shows a second example of the existing antenna port table for DMRS configuration type 2, DMRS maximum length=2.Figure 24 shows a third example of an existing antenna port table for DMRS configuration type 2, maximum DMRS length = 2. Figure 25 shows an example of a new antenna port table for DMRS configuration type 1, maximum DMRS length = 1, the number of extension ports, and rank = 1. Figure 26 shows an example of a new antenna port table for DMRS configuration type 1, maximum DMRS length = 1, the number of extension ports, and rank = 2. Figure 27 shows an example of a new antenna port table for DMRS configuration type 1, maximum DMRS length = 1, the number of extension ports, and rank = 3 or 4. Figure 28 shows another example of a new antenna port table for DMRS configuration type 1, maximum DMRS length = 1, the number of extension ports, and rank = 1. Figure 29 shows another example of a new antenna port table for DMRS configuration type 1, maximum DMRS length = 1, the number of extension ports, and rank = 2. Figure 30 shows another example of a new antenna port table for DMRS configuration type 1, maximum DMRS length = 1, the number of extension ports, and rank = 3 or 4. Figure 31 shows an example of a new antenna port table for DMRS configuration type 1, maximum DMRS length = 2, number of extension ports, and rank = 1. Figure 32 shows an example of a new antenna port table for DMRS configuration type 1, maximum DMRS length = 2, number of extension ports, and rank = 2. Figure 33 shows an example of a new antenna port table for DMRS configuration type 1, maximum DMRS length = 2, number of extension ports, and rank = 3 or 4. Figure 34 shows an example of extension of the new antenna port table. Figure 35 shows an example of a new antenna port table for DMRS configuration type 2, maximum DMRS length = 1, number of extension ports, and rank = 1. Figure 36 shows an example of a new antenna port table for DMRS configuration type 2, maximum DMRS length = 1, number of extension ports, and rank = 2. Figure 37 shows an example of a new antenna port table for DMRS configuration type 2, maximum DMRS length = 1, number of extension ports, and rank = 3 or 4. Figure 38 shows an example of a new antenna port table for DMRS configuration type 2, maximum DMRS length = 2, number of extension ports, and rank = 1. Figure 39 shows an example of a new antenna port table for DMRS configuration type 2, maximum DMRS length = 2, number of extension ports, and rank = 2. Figure 40 shows an example of a new antenna port table for DMRS configuration type 2, maximum DMRS length = 2, number of extension ports, and rank = 3.Figure 41 shows an example of a new antenna port table for DMRS configuration type 2, maximum DMRS length = 2, the number of extension ports, and rank = 4. Figure 42 shows an example of an existing antenna port table for PDSCH, DMRS configuration type = 1, maximum DMRS length = 1. Figure 43 shows an example of an existing antenna port table for PDSCH, DMRS configuration type = 1, maximum DMRS length = 2. Figure 44 shows an example of an existing antenna port table for PDSCH, DMRS configuration type = 2, maximum DMRS length = 1. Figure 45 shows an example of an existing antenna port table for PDSCH, DMRS configuration type = 2, maximum DMRS length = 2. Figure 46 shows an example of a new antenna port table for DMRS configuration type 1, maximum DMRS length = 1, and the number of extension ports according to embodiment #9. Figure 47 shows an example of a first part of a new antenna port table for DMRS configuration type 1, maximum DMRS length = 2, and the number of extension ports according to embodiment #9. FIG. 48 shows an example of a second part of a new antenna port table for a case where DMRS configuration type 1, maximum DMRS length = 2, and the number of extension ports according to embodiment #9. FIG. 49 shows an example of a third part of a new antenna port table for a case where DMRS configuration type 1, maximum DMRS length = 2, and the number of extension ports according to embodiment #9. FIG. 50 shows an example of a group subset for Case 1. FIG. 51 shows an example of a group subset for Case 2. FIG. 52 shows an example of a group subset for Case 3. FIG. 53 shows an example of a group subset for Case 4. FIG. 54 is a diagram showing an example of a schematic configuration of a wireless communication system according to an embodiment. FIG. 55 is a diagram showing an example of a configuration of a base station according to an embodiment. FIG. 56 is a diagram showing an example of a configuration of a user terminal according to an embodiment. FIG. 57 is a diagram showing an example of hardware configurations of a base station and a user terminal according to an embodiment. FIG. 58 is a diagram showing an example of a vehicle according to an embodiment.

[0011] (Beam Management) In NR, a beam management technique is introduced. For example, in NR, forming (or using) a beam in at least one of a base station and a UE is considered.

[0012] By applying beam forming (BF), it is expected that the difficulty of ensuring coverage due to an increase in carrier frequency will be alleviated and radio wave propagation loss will be reduced.

[0013] BF is a technology for forming beams (antenna directivity) by controlling (also called precoding) the amplitude / phase of signals transmitted or received from each element using a massively multi-element antenna. Note that Multiple Input Multiple Output (MIMO) using such massively multi-element antennas is also called massive MIMO.

[0014] Beam sweeping may be performed on both the transmitting and receiving sides to select an appropriate pair from multiple patterns of candidate transmitting and receiving beam pairs. A pair of transmitting and receiving beams may be called a beam pair and may be identified as a beam pair candidate index.

[0015] In beam management, instead of using a single beam, beam control at multiple levels such as a rough beam and a fine beam may be performed.

[0016] BF can be classified into digital BF and analog BF, which may be called digital precoding and analog precoding, respectively.

[0017] Digital BF is a method of performing precoding signal processing (on digital signals) on the baseband, for example. In this case, parallel processing such as inverse fast Fourier transform (IFFT), digital-to-analog converter (DAC), and radio frequency (RF) is required for the number of antenna ports (or RF chains). On the other hand, beams can be formed at any timing, in a number corresponding to the number of RF chains.

[0018] Analog beamforming is a method that uses, for example, a phase shifter on the RF. Although analog beamforming cannot form multiple beams at the same time, it can be easily configured and implemented at low cost because it simply rotates the phase of the RF signal.

[0019] It is also possible to realize a hybrid BF configuration that combines digital and analog BFs. The introduction of large-scale MIMO is being considered for NR, but if a huge number of beams are formed using only digital BFs, the circuit configuration will become expensive, so the use of a hybrid BF configuration is also envisioned.

[0020] (TCI, spatial relationship, QCL) In NR, it is considered to control the reception processing (e.g., at least one of reception, demapping, demodulation, and decoding) and transmission processing (e.g., at least one of transmission, mapping, precoding, modulation, and encoding) of at least one of a signal and a channel (which may be expressed as signal / channel. Similarly, hereinafter, "A / B" may be read as "at least one of A and B") based on the transmission configuration indication state (TCI state).

[0021] The TCI state may represent that which is applied to a downlink signal / channel, and the equivalent of the TCI state that is applied to an uplink signal / channel may be expressed as a spatial relation.

[0022] The TCI state is information about the Quasi-Co-Location (QCL) of signals / channels, and may also be called spatial reception parameters, spatial relation information (SRI), etc. The TCI state may be configured in the UE on a per-channel or per-signal basis.

[0023] The QCL is an index indicating the statistical properties of signals / channels. For example, if a signal / channel has a QCL relationship with another signal / channel, it may mean that it can be assumed that at least one of a Doppler shift, a Doppler spread, an average delay, a delay spread, and a spatial parameter (e.g., a spatial Rx parameter) is the same between these different signals / channels (i.e., the signals / channels have a QCL with respect to at least one of these).

[0024] The spatial reception parameters may correspond to a reception beam (e.g., a reception analog beam) of the UE, and the beam may be identified based on a spatial QCL. The QCL (or at least one element of the QCL) in the present disclosure may be replaced with sQCL (spatial QCL).

[0025] A plurality of types (QCL types) of QCL may be defined. For example, four QCL types A to D may be provided, each having different parameters (or parameter sets) that can be assumed to be the same, and the parameters (which may be referred to as QCL parameters) are as follows: QCL type A: Doppler shift, Doppler spread, mean delay, and delay spread QCL type B: Doppler shift and Doppler spread QCL type C: Doppler shift and mean delay QCL type D: Spatial reception parameters

[0026] Types A to C may correspond to QCL information related to synchronization processing of at least one of time and frequency, and type D may correspond to QCL information related to beam control.

[0027] The UE's assumption that a given Control Resource Set (CORESET), channel, or reference signal has a specific QCL (e.g., QCL type D) relationship with another CORESET, channel, or reference signal may be referred to as a QCL assumption.

[0028] The UE may determine at least one of a transmit beam (Tx beam) and a receive beam (Rx beam) for a signal / channel based on the TCI condition or QCL assumption of the signal / channel.

[0029] The TCI state may be, for example, information about the QCL between a target channel (or a Reference Signal (RS) for that channel) and another signal (e.g., another Downlink Reference Signal (DL-RS)). The TCI state may be set (indicated) by higher layer signaling, physical layer signaling, or a combination thereof.

[0030] In the present disclosure, higher layer signaling may be, for example, any one of Radio Resource Control (RRC) signaling, Medium Access Control (MAC) signaling, broadcast information, and the like, or a combination thereof.

[0031] The MAC signaling may use, for example, a MAC Control Element (MAC CE), a MAC Protocol Data Unit (PDU), etc. The 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.

[0032] The physical layer signaling may be, for example, Downlink Control Information (DCI).

[0033] The channel for which the TCI state is set (designated) may be, for example, at least one of a downlink shared channel (Physical Downlink Shared Channel (PDSCH)), a downlink control channel (Physical Downlink Control Channel (PDCCH)), an uplink shared channel (Physical Uplink Shared Channel (PUSCH)), and an uplink control channel (Physical Uplink Control Channel (PUCCH)).

[0034] Furthermore, the RS (DL-RS) that has a QCL relationship with the channel may be, for example, at least one of a synchronization signal block (SSB), a channel state information reference signal (CSI-RS), and a sounding reference signal (SRS). Alternatively, the DL-RS may be a CSI-RS (also called a tracking reference signal (TRS)) used for tracking, or a reference signal (also called a QRS) used for QCL detection.

[0035] An SSB is a signal block including at least one of a Primary Synchronization Signal (PSS), a Secondary Synchronization Signal (SSS), and a Physical Broadcast Channel (PBCH). An SSB may also be referred to as an SS / PBCH block.

[0036] The TCI state information element ("TCI-state IE" in RRC) set by higher layer signaling may include one or more pieces of QCL information ("QCL-Info"). The QCL information may include at least one of information on DL-RSs having a QCL relationship (DL-RS relationship information) and information indicating a QCL type (QCL type information). The DL-RS relationship information may include information such as an index of the DL-RS (e.g., an SSB index, a Non-Zero-Power (NZP) CSI-RS resource identifier), an index of a cell in which the RS is located, and an index of a Bandwidth Part (BWP) in which the RS is located.

[0037] (Advances in MIMO Technology and Beams) Incidentally, MIMO technology has been used in frequency bands (or frequency bands) lower than 6 GHz until now, but it is being considered that it will be applied to frequency bands higher than 6 GHz in the future.

[0038] Note that frequency bands lower than 6 GHz may be called sub-6, Frequency Range (FR) 1, etc. Frequency bands higher than 6 GHz may be called above-6, FR2, millimeter wave (mmW), FR4, etc.

[0039] The maximum number of MIMO layers is assumed to be limited by the antenna size.

[0040] Even at mmW, the use of higher-order MIMO and cooperation among multiple UEs can improve the freedom and diversity of MIMO multiplexing, and ultimately improve throughput.

[0041] In this way, it is expected that future wireless communication systems (e.g., NR from Rel-17 onwards) will use only digital beams (which may be called full digital operation) without analog beams, even at high frequencies (e.g., FR2), or will use operations that predominantly use digital beams.

[0042] For example, in the case of full digital operation, by simultaneously applying orthogonal precoding (or orthogonal beams, digital beams) to multiple UEs, it is expected that frequency utilization efficiency will be improved. If the digital beam cannot be applied appropriately, interference between UEs will increase, leading to deterioration of communication quality (or reduction in cell capacity). Note that orthogonal in the present disclosure may be interpreted as quasi-orthogonal.

[0043] If a base station (which may be read as a Transmission / Reception Point (TRP), panel, etc.) can transmit only one beam at a time, the base station switches the beam to transmit and receive to the UE. If a base station can transmit multiple beams at a time, the base station can simultaneously transmit and receive to and from multiple UEs using different beams.

[0044] Even if base stations become fully digital, as long as Rel-15 UEs exist, they should be accommodated (supported).

[0045] (DMRS) The front-loaded DMRS is the first DMRS (at or near the first symbol) for faster demodulation. An additional DMRS can be configured by RRC for fast-moving UEs or high modulation and coding scheme (MCS) / rank. The frequency location of the additional DMRS is the same as that of the front-loaded DMRS.

[0046] 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.

[0047] 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.

[0048] 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.

[0049] Single symbol DMRS or double symbol DMRS is configured.

[0050] 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.

[0051] Double-symbol DMRS is used for more DMRS ports (especially MU-MIMO). In double-symbol DMRS, the number of additional DMRS (symbols) is {0, 1}. Double-symbol DMRS is supported when frequency hopping is disabled. If the maximum number (maxLength) in the uplink DMRS configuration (DMRS-UplinkConfig) is 2 (len2), whether single-symbol DMRS or double-symbol DMRS is used is determined by the DCI or configured grant.

[0052] 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

[0053] Multiple DMRS ports that are mapped to the same RE (time and frequency resource) are called a DMRS CDM group.

[0054] For DMRS configuration type 1 and single-symbol DMRS, four DMRS ports can be used. Within each DMRS CDM group, two DMRS ports are multiplexed using FD OCC of length 2. Between multiple DMRS CDM groups (two DMRS CDM groups), two DMRS ports are multiplexed using FDM.

[0055] For DMRS configuration type 1 and double-symbol DMRS, eight DMRS ports can be used. Within each DMRS CDM group, two DMRS ports are multiplexed by an FD OCC of length 2, and two DMRS ports are multiplexed by a TD OCC. Between multiple DMRS CDM groups (two DMRS CDM groups), two DMRS ports are multiplexed by FDM.

[0056] 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.

[0057] 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.

[0058] Here, an example of DMRS mapping type B is shown, but DMRS mapping type A is also similar.

[0059] 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.

[0060] 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.

[0061] (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.

[0062] 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.

[0063] 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.

[0064] In Rel-15 NR, multi-port DMRS is supported by using frequency division multiplexing (FDM), frequency domain orthogonal cover code (FD-OCC), time domain OCC (TD-OCC), etc., with up to eight ports for Type 1 DMRS (i.e., DMRS configuration type 1) and up to 12 ports for Type 2 DMRS (i.e., DMRS configuration type 2).

[0065] 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.

[0066] The OCC in the present disclosure may be interchangeably read as orthogonal code, orthogonalization, cyclic shift, and the like.

[0067] The type of DMRS may be referred to as a DMRS configuration type.

[0068] 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.

[0069] 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.

[0070] 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).

[0071] In the case of DMRS configuration type 1 and double-symbol DMRS, 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}).

[0072] 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.

[0073] 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.

[0074] 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.

[0075] 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.

[0076] 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.

[0077] 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').

[0078] The TD-OCC and FD-OCC of the DMRS of Rel. 15 NR both correspond to OCCs with a sequence length (which may also be referred to as the OCC length) of 2. Therefore, the possible values ​​of k' and l' above are both 0 and 1. By multiplying this FD-OCC in RE units, two-port DMRS can be multiplexed using the same time and frequency resources (2 RE). When both the FD-OCC and TD-OCC are applied, four-port DMRS can be multiplexed using the same time and frequency resources (4 RE).

[0079] The two existing DMRS port tables for PDSCH described above correspond to DMRS configuration type 1 and type 2, respectively. Note that p indicates the antenna port number, and Δ indicates a parameter for shifting (offsetting) the frequency resource.

[0080] For example, for antenna ports 1000 and 1001, {w ｆ (0), w ｆ (1)} = {+1, +1} and {w ｆ (0), w ｆ (1)}={+1, -1} is applied to the vectors, and the vectors are orthogonalized using FD-OCC.

[0081] 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.

[0082] 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.

[0083] 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.

[0084] 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.

[0085] In Rel. 18, increasing the total number of DMRS ports to 8, 16, 12, and 24 for Cases 1, 2, 3, and 4, respectively, is considered.

[0086] The DMRS CDM group and the associated DMRS port indication table have not yet been fully considered, and if they are not clear, communication throughput / communication quality may be degraded.

[0087] Therefore, the present inventors have devised a method for setting / determining DMRS ports / DMRS CDM groups.

[0088] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. Each of the following embodiments (e.g., each case) may be used alone or in combination of at least two of them.

[0089] In the present disclosure, "A / B" and "at least one of A and B" may be interpreted interchangeably. Also, in the present disclosure, "A / B / C" may mean "at least one of A, B, and C."

[0090] 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.

[0091] 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.

[0092] In the present disclosure, higher layer signaling may be, for example, any one of Radio Resource Control (RRC) signaling, Medium Access Control (MAC) signaling, broadcast information, and the like, or a combination thereof.

[0093] 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.

[0094] In the present disclosure, physical layer signaling may be, for example, Downlink Control Information (DCI), Uplink Control Information (UCI), and the like.

[0095] 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.

[0096] In the present disclosure, the terms panel, UE panel, panel group, beam, beam group, precoder, Uplink (UL) transmitting entity, Transmission / Reception Point (TRP), base station, Spatial Relation Information (SRI), spatial relation, SRS Resource Indicator (SRI), Control Resource Set (CORESET), Physical Downlink Shared Channel (PDSCH), Codeword (CW), Transport Block (TB), Reference Signal (RS), antenna port (e.g., Demodulation Reference Signal (DMRS) port), antenna port group (e.g., DMRS port group), group (e.g., spatial relation group, Code Division Multiplexing (CDM) group, reference signal group, CORESET group, Physical Uplink Control Channel (PUCCH) group, PUCCH resource group), resource (e.g., reference signal resource, SRS resource), resource set (e.g., reference signal resource set), CORESET pool, downlink Transmission Configuration Indication state (TCI state) (DL TCI state), uplink TCI state (UL TCI state), unified TCI state, common TCI state, Quasi-Co-Location (QCL), QCL assumption, etc. may be read as interchangeable.

[0097] In the present disclosure, time domain resource allocation and time domain resource assignment may be read interchangeably.

[0098] (Wireless communication method) In each embodiment, DMRS, DL DMRS, UL DMRS, PDSCH DMRS, and PUSCH DMRS may be interchangeable.

[0099] In each embodiment, the orthogonal sequence, OCC, FD OCC, and TD OCC may be interchangeable.

[0100] In each embodiment, the DMRS port, antenna port, and port may be interchangeable. In each embodiment, the port index and port number may be interchangeable. In each embodiment, the DMRS CDM group and CDM group may be interchangeable. In each embodiment, the antenna port indication and antenna port field may be interchangeable.

[0101] In each embodiment, the terms "CDM group list" and "list" may be interchangeable. In each embodiment, the terms "CDM group subset" and "group subset" may be interchangeable.

[0102] In each embodiment, the DMRS for PDSCH (DMRS ports 1000-10xx) and the DMRS for PUSCH (DMRS ports 0-xx) may be read as interchangeable.

[0103] - Analysis #1 Figure 3 shows an example of a new DMRS port table for increasing the number of DMRS ports for PDSCH DMRS configuration type 1. Figure 4 shows another example of a new DMRS port table for increasing the number of DMRS ports for PDSCH DMRS configuration type 1. Such a new DMRS port table and the new FD OCC W f (k') / TD OCC W tBy using (l') / DMRS allocation, the number of DMRS ports can be increased from the existing number of DMRS ports. f (k') may have the same length as the existing FD OCC, or may be longer than the existing FD OCC. f (k') may be a sequence having values ​​of 0 and 1, or may be a sequence having complex values. In this new DMRS port table, the CDM group for the new DMRS port is the existing CDM group.

[0104] The UE may receive the DMRS configuration and control transmission and reception of the DMRS based on one or more associations and configurations between the CDM groups and the DMRS ports. The number of the CDM groups for DMRS configuration type 1 may be greater than two, and the number of the CDM groups for DMRS configuration type 2 may be greater than three.

[0105] <Embodiment #1> This embodiment relates to mapping of CDM groups and DMRS port indices (e.g., DMRS port index order, CDM group order, CDM grouping order / method).

[0106] In Cases 1 to 4 of Rel. 15, the mapping of CDM groups and DMRS port indices is as follows:

[0107] [Case 1] Four ports and two CDM groups may be available. For the PUSCH, CDM group #0 may correspond to DMRS port indices {0,1}, and CDM group #1 may correspond to DMRS port indices {2,3}. For the PDSCH, CDM group #0 may correspond to DMRS port indices {1000,1001}, and CDM group #1 may correspond to DMRS port indices {1002,1003}.

[0108] [Case 2] Eight ports and two CDM groups may be available. For the PUSCH, CDM group #0 may correspond to DMRS port indices {0, 1, 4, 5}, and CDM group #1 may correspond to DMRS port indices {2, 3, 6, 7}. For the PDSCH, CDM group #0 may correspond to DMRS port indices {1000, 1001, 1004, 1005}, and CDM group #1 may correspond to DMRS port indices {1002, 1003, 1006, 1007}.

[0109] [Case 3] Six ports and three CDM groups may be available. For the PUSCH, CDM group #0 may correspond to DMRS port index {0,1}, CDM group #1 may correspond to DMRS port index {2,3}, and CDM group #2 may correspond to DMRS port index {4,5}. For the PDSCH, CDM group #0 may correspond to DMRS port index {1000,1001}, CDM group #1 may correspond to DMRS port index {1002,1003}, and CDM group #2 may correspond to DMRS port index {1004,1005}.

[0110] [Case 4] 12 ports and 3 CDM groups may be available. For the PUSCH, CDM group #0 may correspond to DMRS port indices {0, 1, 6, 7}, CDM group #1 may correspond to DMRS port indices {2, 3, 8, 9}, and CDM group #2 may correspond to DMRS port indices {4, 5, 10, 11}. For the PDSCH, CDM group #0 may correspond to DMRS port indices {1000, 1001, 1006, 1007}, CDM group #1 may correspond to DMRS port indices {1002, 1003, 1008, 1009}, and CDM group #2 may correspond to DMRS port indices {1004, 1005, 1010, 1011}.

[0111] In this embodiment, the mapping of CDM groups and DMRS port indices may follow either of the following options 1 and 2.

[0112] Option 1: The UE may support new CDM groups for new (more) DMRS ports. In this case, the UE may support at least one of the following cases 1 to 4:

[0113] [Case 1] Eight ports may be available. Two CDM groups may be maintained, similar to the existing DMRS port table. For PUSCH, CDM group #0 may correspond to DMRS port index {0,1}, and CDM group #1 may correspond to DMRS port index {2,3}. For PDSCH, CDM group #0 may correspond to DMRS port index {1000,1001}, and CDM group #1 may correspond to DMRS port index {1002,1003}.

[0114] [Case 2] 16 ports may be available. Four CDM groups may be available according to either of the following options 1 and 2. [[Option 1]] Four CDM groups may be available by extending / adding two existing CDM groups. For PUSCH, CDM group #0 may correspond to DMRS port index {0, 1, 4, 5}, CDM group #1 may correspond to DMRS port index {2, 3, 6, 7}, CDM group #2 may correspond to DMRS port index {8, 9, 10, 13}, and CDM group #3 may correspond to DMRS port index {10, 11, 14, 15}. For the PDSCH, CDM group #0 may correspond to DMRS port indices {1000, 1001, 1004, 1005}, CDM group #1 may correspond to DMRS port indices {1002, 1003, 1006, 1007}, CDM group #2 may correspond to DMRS port indices {1008, 1009, 1012, 1013}, and CDM group #3 may correspond to DMRS port indices {1010, 1011, 1014, 1015}. [Option 2] Four CDM groups may be available with the new mapping order.

[0115] [Case 3] Twelve ports may be available. Three CDM groups may be maintained, similar to the existing DMRS port table. For the PUSCH, CDM group #0 may correspond to DMRS port indices {0, 1, 6, 7}, CDM group #1 may correspond to DMRS port indices {2, 3, 8, 9}, and CDM group #2 may correspond to DMRS port indices {4, 5, 10, 11}. For the PDSCH, CDM group #0 may correspond to DMRS port indices {1000, 1001, 1006, 1007}, CDM group #1 may correspond to DMRS port indices {1002, 1003, 1008, 1009}, and CDM group #2 may correspond to DMRS port indices {1004, 1005, 1010, 1011}.

[0116] [Case 4] 24 ports may be available. Six CDM groups may be available according to either of the following options 3 and 4. [[Option 3]] Six CDM groups may be available by extending / adding two existing CDM groups. For PUSCH, CDM group #0 may correspond to DMRS port index {0, 1, 6, 7}, CDM group #1 may correspond to DMRS port index {2, 3, 8, 9}, CDM group #2 may correspond to DMRS port index {4, 5, 10, 11}, CDM group #3 may correspond to DMRS port index {12, 13, 18, 19}, CDM group #4 may correspond to DMRS port index {14, 15, 20, 21}, and CDM group #5 may correspond to DMRS port index {16, 17, 22, 23}. For the PDSCH, CDM group #0 may correspond to DMRS port indices {1000, 1001, 1006, 1007}, CDM group #1 may correspond to DMRS port indices {1002, 1003, 1008, 1009}, CDM group #2 may correspond to DMRS port indices {1004, 1005, 1010, 1011}, CDM group #3 may correspond to DMRS port indices {1012, 1013, 1018, 1019}, CDM group #4 may correspond to DMRS port indices {1014, 1015, 1020, 1021}, and CDM group #5 may correspond to DMRS port indices {1016, 1017, 1022, 1023}. [Option 4] Six CDM groups may be available with the new mapping order.

[0117] Consider the PDSCH example for option 1 / 3 in case 2 / 4 above. It is similar to the PUSCH except that the DMRS port index starts from 0.

[0118] The number of CDM groups is increased in at least one of the cases where the number of DMRS ports for DMRS configuration type 1 is greater than 8 and where the number of DMRS ports for DMRS configuration type 2 is greater than 12.

[0119] In option 1 / 3, for each DMRS configuration type, a unified DMRS port table for single symbol DMRS and double symbol DMRS may be defined, since the same DMRS port index belongs to the same CDM group in both single symbol DMRS and double symbol DMRS.

[0120] 5 shows an example of a new DMRS port table for DMRS configuration type 1 according to option 1. In this example, the number of CDM groups is 2 even though the number of supported DMRS ports for DMRS configuration type 1 and single-symbol DMRS is increased to 8.

[0121] 6 shows an example of a new DMRS port table for DMRS configuration type 2 according to option 1. In this example, even though the number of supported DMRS ports for DMRS configuration type 2 and single-symbol DMRS is increased to 12, the number of CDM groups is still 2.

[0122] In Option 2 / 4 of the above Case 2 / 4, a new mapping order of DMRS CDM groups and DMRS port indices may be defined.

[0123] 7 shows an example of a new DMRS port table for DMRS configuration type 1 according to option 2. For PDSCH, CDM group #0 corresponds to DMRS port indices {1000, 1001, 1008, 1009}, CDM group #1 corresponds to DMRS port indices {1002, 1003, 1010, 1011}, CDM group #2 corresponds to DMRS port indices {1004, 1005, 1012, 1013}, and CDM group #3 corresponds to DMRS port indices {1006, 1007, 1014, 1015}.

[0124] 8 shows an example of a new DMRS port table for DMRS configuration type 2 according to option 2. For PDSCH, CDM group #0 corresponds to DMRS port index {1000, 1001, 1012, 1013}, CDM group #1 corresponds to DMRS port index {1002, 1003, 1014, 1015}, CDM group #2 corresponds to DMRS port index {1004, 1005, 1016, 1016}, CDM group #3 corresponds to DMRS port index {1006, 1007, 1018, 1019}, CDM group #4 corresponds to DMRS port index {1008, 1009, 1020, 1021}, and CDM group #5 corresponds to DMRS port index {1010, 1011, 1022, 1023}.

[0125] In option 2 / 4, for each DMRS configuration type, a unified DMRS port table for single-symbol DMRS and double-symbol DMRS may be defined, such that the same DMRS port index belongs to the same CDM group in both single-symbol DMRS and double-symbol DMRS.

[0126] Option 2: The UE may support new CDM groups for enhanced DMRS configuration type 1 / 2 (e.g., Rel / 18 DMRS configuration type 1 / 2). In this case, the UE may support at least one of the following cases 1 to 4:

[0127] [Case 1] Eight ports may be available. Four CDM groups may be available. Figure 9 shows an example of a new DMRS port table. For the PUSCH, CDM group #0 may correspond to DMRS port index {0,1}, CDM group #1 may correspond to DMRS port index {2,3}, CDM group #2 may correspond to DMRS port index {4,5}, and CDM group #3 may correspond to DMRS port index {6,7}. For the PDSCH, CDM group #0 may correspond to DMRS port index {1000,1001}, CDM group #1 may correspond to DMRS port index {1002,1003}, CDM group #2 may correspond to DMRS port index {1004,1005}, and CDM group #3 may correspond to DMRS port index {1006,1007}.

[0128] [Case 2] 16 ports may be available. 4 CDM groups may be available. The mapping of CDM groups and DMRS port indices may be similar to option 1 / 3 of case 2 in option 1 above.

[0129] [Case 3] 12 ports may be available. 6 CDM groups may be available. Figure 10 shows an example of a new DMRS port table. For PUSCH, CDM group #0 may correspond to DMRS port index {0,1}, CDM group #1 may correspond to DMRS port index {2,3}, CDM group #2 may correspond to DMRS port index {4,5}, CDM group #3 may correspond to DMRS port index {6,7}, CDM group #4 may correspond to DMRS port index {8,9}, and CDM group #5 may correspond to DMRS port index {10,11}. For the PDSCH, CDM group #0 may correspond to DMRS port index {1000, 1001}, CDM group #1 may correspond to DMRS port index {1002, 1003}, CDM group #2 may correspond to DMRS port index {1004, 1005}, CDM group #3 may correspond to DMRS port index {1006, 1007}, CDM group #4 may correspond to DMRS port index {1008, 1009}, and CDM group #5 may correspond to DMRS port index {1010, 1011}.

[0130] Case 4: 24 ports may be available. 6 CDM groups may be available. The mapping of CDM groups and DMRS port indices may be similar to options 2 / 4 of Case 4 in Option 1 above.

[0131] If Option 2 is adopted for single-symbol DMRS, it may be aligned with Alternative 2 / 4, in which case, for each DMRS configuration type, a unified DMRS port table for single-symbol DMRS and double-symbol DMRS may be defined, such that the same DMRS port index in both single-symbol DMRS and double-symbol DMRS belongs to the same CDM group.

[0132] According to this embodiment, the UE can properly determine the relationship between the DMRS port and the CDM group.

[0133] <Embodiment #2> This embodiment relates to a DMRS sequence.

[0134] As shown in the example of FIG. 11, the pseudo-random sequence generator of the pseudo-random sequence c(i) used to generate the DMRS sequence r(n) is set to an initial value c init Rel. 16 uses the CDM group specific c to reduce the PAPR to the same level as the data symbol for all port combinations. init Support.

[0135] Same as Rel. 16 init In the above, identifier n - SCID λ- may be used, where n - may be written by writing a - (bar) over n, and may be called n-bar. λ- may be written by writing a - (bar) over λ, and may be called λ-bar.

[0136] n for new values ​​of CDM group index λ (e.g., λ=3, 4, 5) - SCID λ- For λ=0, 2, 4, n - SCID λ- = n SCID For λ=1, 3, 5, n - ID λ- = 1-n SCID n for λ may be - ID λ- However, it is not limited to this and may be given by other formulas. ID ^(n - SCID λ- ) is the scrambling ID (higher layer parameter N ID 0 , N ID 1 based on the physical layer cell identity NID cell and n SCID ∈{0,1}.

[0137] According to this embodiment, the UE can appropriately determine the relationship between the CDM group and the DMRS sequence.

[0138] <Embodiment #0-1> This embodiment relates to mapping of CDM groups and DMRS ports.

[0139] In the CDM group in Option 1 / 2 of Embodiment #1, a new concept of a CDM group list (list) may be introduced above the CDM group. The number of CDM groups and the order of the CDM groups for each CDM group list may follow the existing DMRS port table. The CDM group list may support at least one of the following Cases 1 to 4.

[0140] [Case 1] 8 ports may be available. 2 CDM group lists may be available. There may be 2 CDM groups per CDM group list. There may be 2 DMRS ports per CDM group. List #1 may contain CDM groups {0,1} and list #2 may contain CDM groups {2,3}.

[0141] [Case 2] 16 ports may be available. 2 CDM group lists may be available. There may be 2 CDM groups per CDM group list. There may be 4 DMRS ports per CDM group. List #1 may contain CDM groups {0,1} and list #2 may contain CDM groups {2,3}.

[0142] [Case 3] 12 ports may be available. 2 CDM group lists may be available. There may be 3 CDM groups per CDM group list. There may be 2 DMRS ports per CDM group. List #1 may contain CDM groups {0,1,2} and list #2 may contain CDM groups {3,4,5}.

[0143] [Case 4] 24 ports may be available. 2 CDM group lists may be available. There may be 3 CDM groups per CDM group list. There may be 4 DMRS ports per CDM group. List #1 may contain CDM groups {0,1,2} and list #2 may contain CDM groups {3,4,5}.

[0144] For each DMRS port in the list, the order of the CDM groups in the existing DMRS port table may be reused. For the second list, the DMRS port index j in the DMRS port table may mean j+P, where P may be the number of DMRS ports in the list (the maximum number of DMRS ports in the list). For the second list, the DMRS CDM group index k in the DMRS port table may mean k+Q, where Q may be the number of DMRS CDM groups in the list (the maximum number of DMRS CDM groups in the list).

[0145] Figure 12 shows an example of a CDM group list for Case 1. In the DMRS port table, DMRS ports {1000, 1001, 1002, 1003} correspond to CDM groups {0, 0, 1, 1}, respectively. The mapping for List #1 is as shown in the DMRS port table. The mapping for List #2 is as shown in the DMRS port table, where P=4 and Q=2 are applied to the DMRS port table, so that DMRS port j+P corresponds to CDM group k+Q.

[0146] Figure 13 shows an example of a CDM group list for Case 2. In the DMRS port table, DMRS ports {1000, 1001, 1002, 1003, 1004, 1005, 1006, 1007} ​​correspond to CDM groups {0, 0, 1, 1, 0, 0, 1, 1}, respectively. The mapping for List #1 is as shown in the DMRS port table. The mapping for List #2 is as shown in the DMRS port table, where P=8 and Q=2 are applied to the DMRS port table, so that DMRS port j+P corresponds to CDM group k+Q.

[0147] Figure 14 shows an example of a CDM group list for Case 3. In the DMRS port table, DMRS ports {1000, 1001, 1002, 1003, 1004, 1005} correspond to CDM groups {0, 0, 1, 1, 2, 2}, respectively. The mapping for list #1 is as shown in the DMRS port table. The mapping for list #2 is as shown in the DMRS port table, where P=6 and Q=3 are applied to the DMRS port table, so that DMRS port j+P corresponds to CDM group k+Q.

[0148] Figure 15 shows an example of a CDM group list for Case 4. In the DMRS port table, DMRS ports {1000, 1001, 1002, 1003, 1004, 1005, 1006, 1007, 1008, 1009, 1010, 1011} correspond to CDM groups {0, 0, 1, 1, 2, 2, 0, 0, 1, 1, 2, 2}, respectively. The mapping for List #1 is as shown in the DMRS port table. The mapping for List #2 is as shown in the DMRS port table, where P = 12 and Q = 3 are applied to the DMRS port table, so that DMRS port j + P corresponds to CDM group k + Q.

[0149] According to this embodiment, the number of CDM groups and DMRS ports can be increased appropriately.

[0150] <Embodiment #0-2> This embodiment relates to a DMRS structure.

[0151] In Rel. 16 / 17, different CDM groups are FDM'd.

[0152] Since the received signals between different UEs with different received powers have a near-far problem (i.e., received signals from close distances affect received signals from far distances), for MU-MIMO, the base station may assign different CDM groups to different UEs.

[0153] As the number of CDM groups increases, how to allocate REs to the CDM groups becomes an issue.

[0154] 16 shows an example of mapping (allocation) of CDM groups to REs for DMRS configuration types 1 and 2. For DMRS configuration type 1, four CDM groups may be FDM-multiplexed using a comb structure with a transmission comb number of 4. For DMRS configuration type 2, six CDM groups may be FDM-multiplexed with two REs each.

[0155] - Analysis #2 For PUSH, the antenna port indication (antenna port field) in DCI format 0_1 / 0_2 may indicate a CDM group number > 2 for DMRS configuration type 1 and a CDM group number > 3 for DMRS configuration type 2.

[0156] The existing antenna port table can only indicate that the number of CDM groups is ≦2 for DMRS configuration type 1, and can only indicate that the number of CDM groups is ≦3 for DMRS configuration type 2.

[0157] In the legacy antenna port table for a combination of DMRS configuration type (dmrs-Type), DMRS maximum length (maxLength, maximum number of DMRS symbols), and rank (rank), the value of the antenna port indication is associated with the number of DMRS CDM groups (the number of DMRS CDM groups without data) and the DMRS port index. For DMRS configuration type 1 and DMRS maximum length = 1, Figure 17 shows an example of the legacy antenna port table for rank = 1, 2, 3, or 4. For DMRS configuration type 1 and DMRS maximum length = 2, Figures 18 and 19 show examples of the legacy antenna port table for rank = 1, 2, 3, or 4. For DMRS configuration type 2 and DMRS maximum length = 1, Figures 20 and 21 show examples of the legacy antenna port table for rank = 1, 2, 3, or 4. For DMRS configuration type 2 and maximum DMRS length=2, Figures 22, 23, and 24 show examples of existing antenna port tables for rank=1, 2, 3, and 4.

[0158] The UE may receive a DCI (DCI format) including a PUSCH resource allocation and a value for an antenna port indication (antenna port field), and control the transmission of DMRS based on the association between the value, the number of CDM groups, and the DMRS port.

[0159] The extension of the antenna port indication for PUSCH may follow either of the following directions #2-1 and #2-2.

[0160] --Direction #2-1 A new antenna port table may be defined for the following cases 1 to 4 (embodiments #3 to #7): [Case 1] DMRS setting type 1, maximum DMRS length = 1, number of ports = 8, rank = 1 / 2 / 3 / 4 [Case 2] DMRS setting type 1, maximum DMRS length = 2, number of ports = 16, rank = 1 / 2 / 3 / 4 [Case 3] DMRS setting type 2, maximum DMRS length = 1, number of ports = 12, rank = 1 / 2 / 3 / 4 [Case 4] DMRS setting type 2, maximum DMRS length = 2, number of ports = 24, rank = 1 / 2 / 3 / 4

[0161] Different options in embodiment #1 describe different CDM grouping orders / methods. For different CDM grouping methods, the DMRS port index in each CDM group may be different, and the antenna port table may be different. For simplicity and to be applicable to all CDM grouping methods, in each of the following embodiments, x,y (or i_x,y) may represent the y-th DMRS port index in the x-th CDM group (CDM group #(x-1)), where x>=1, y>=1.

[0162] For example, in the example of the DMRS port table (FIG. 5) of option 1 of embodiment # above, i 1,1 =1000, i 1,2 =1001, i 1,3 =1004, i 1,4 =1005, i 2,1 =1002, i 2,2 =1003, ...

[0163] For example, in the example of the DMRS port table (FIG. 7) of option 2 of option 1 of embodiment # described above, 1,1 =1000, i 1,2 =1001, i 1,3 =1008, i 1,4 =1009, i 2,1 =1002, i 2,2 =1003, ...

[0164] <Embodiment #3> This embodiment relates to a new antenna port table for Case 1 of PUSCH.

[0165] The DMRS setting type may be 1, the maximum DMRS length may be 1, and the number of extension ports (number of DMRS ports) may be 8 (Case 1).

[0166] <<Assumption A>> Option 1 of embodiment #1 may be applied to two CDM groups for eight ports. Four existing antenna port tables for Case 1 may be reused for Case 1 with the extended number of ports. The field size (number of bits) of the antenna port indication may be increased to four bits.

[0167] <<Scenario B>> Option 2 of embodiment #1 may be applied to 4 CDM groups for 8 ports.

[0168] The field size (number of bits) of the antenna port indication may be increased so that the new antenna port table includes entries with DMRS CDM group numbers {3,4} without data. DMRS CDM group numbers 1, 2, 3, and 4 without data may refer to CDM groups {0}, {0,1}, {0,1,2}, and {0,1,2,3}, respectively. The antenna port table may be defined to have all or some of the entries in the following example new antenna port table: Example of a new antenna port table with DMRS setting type 1, maximum DMRS length = 1, number of extension ports, and rank = 1 ( FIG. 25 ) Example of a new antenna port table with DMRS setting type 1, maximum DMRS length = 1, number of extension ports, and rank = 2 ( FIG. 26 ) Example of a new antenna port table with DMRS setting type 1, maximum DMRS length = 1, number of extension ports, and rank = 3 (first table in FIG. 27 ) Example of a new antenna port table with DMRS setting type 1, maximum DMRS length = 1, number of extension ports, and rank = 4 (second table in FIG. 27 )

[0169] The new antenna port table may include the assumption of the CDM grouping order / method of option 2 of embodiment #1. 1,1 =0, i 1,2 =1, i 2,1 =2, i 2,2 =3, i 3,1 = 4, i 3,2 =5, i 4,1 =6, i 4,2 = 7. The antenna port table may be specified to have entries of all or some of the following examples of new antenna port tables: Example of a new antenna port table with DMRS configuration type 1, maximum DMRS length = 1, number of extension ports, and rank = 1 (Figure 28) Example of a new antenna port table with DMRS configuration type 1, maximum DMRS length = 1, number of extension ports, and rank = 2 (Figure 29) Example of a new antenna port table with DMRS configuration type 1, maximum DMRS length = 1, number of extension ports, and rank = 3 (first table in Figure 30) Example of a new antenna port table with DMRS configuration type 1, maximum DMRS length = 1, number of extension ports, and rank = 4 (second table in Figure 30)

[0170] According to this embodiment, antenna port indication in case 1 of PUSCH can be performed appropriately.

[0171] <Embodiment #4> This embodiment relates to a new antenna port table for Case 2 of PUSCH.

[0172] The DMRS setting type may be 1, the maximum DMRS length may be 2, and the number of extension ports (number of DMRS ports) may be 16 (Case 2).

[0173] The field size (number of bits) of the antenna port indication may be increased so that the new antenna port table includes entries with DMRS CDM group numbers {3,4} without data. DMRS CDM group numbers 1, 2, 3, and 4 without data may refer to CDM groups {0}, {0,1}, {0,1,2}, and {0,1,2,3}, respectively. The antenna port table may be defined to have all or some of the entries in the following example new antenna port table: Example of a new antenna port table with DMRS setting type 1, maximum DMRS length = 2, number of extension ports, and rank = 1 ( FIG. 31 ) Example of a new antenna port table with DMRS setting type 1, maximum DMRS length = 2, number of extension ports, and rank = 2 ( FIG. 32 ) Example of a new antenna port table with DMRS setting type 1, maximum DMRS length = 2, number of extension ports, and rank = 3 (first table in FIG. 33 ) Example of a new antenna port table with DMRS setting type 1, maximum DMRS length = 2, number of extension ports, and rank = 4 (second table in FIG. 33 )

[0174] In these examples, the number of forward (DMRS) symbols may be 1 or 2. Some rows may be repeated using two values ​​(for the number of forward symbols). For example, the four rows for the number of CDM groups=2 (rows with values ​​1 to 4) in the example of the first antenna port table in Figure 33 may be expanded to eight rows by being repeated using a different number of forward symbols, as in the example of Figure 34.

[0175] According to this embodiment, antenna port indication in case 2 of PUSCH can be performed appropriately.

[0176] <Embodiment #5> This embodiment relates to a new antenna port table for Case 3 of PUSCH.

[0177] DMRS setting type 2, maximum DMRS length = 1, number of extension ports (number of DMRS ports) = 12 (Case 3).

[0178] <<Assumption A>> Option 1 of embodiment #1 may be applied to three CDM groups for 12 ports. Four existing antenna port tables for Case 3 may be reused for Case 3 with an extended number of ports. The field size (number of bits) of the antenna port indication may be increased to five bits.

[0179] <<Scenario B>> Option 2 of embodiment #1 may be applied to 6 CDM groups for 12 ports.

[0180] The antenna port indication field size (number of bits) may be increased so that the new antenna port table includes entries with DMRS CDM group numbers {4, 5, 6} without data. DMRS CDM group numbers 1, 2, 3, 4, 5, 6 without data may refer to CDM groups {0}, {0, 1}, {0, 1, 2}, {0, 1, 2, 3}, {0, 1, 2, 3, 4}, and {0, 1, 2, 3, 4, 5}, respectively. The antenna port table may be defined to have all or some of the entries in the following example new antenna port table: An example of a new antenna port table with DMRS configuration type 2, maximum DMRS length = 1, number of extension ports, and rank = 1 ( FIG. 35 ). An example of a new antenna port table with DMRS configuration type 2, maximum DMRS length = 1, number of extension ports, and rank = 2 ( FIG. 36 ). An example of a new antenna port table with DMRS configuration type 2, maximum DMRS length = 1, number of extension ports, and rank = 3 (first table in FIG. 37 ). An example of a new antenna port table with DMRS configuration type 2, maximum DMRS length = 1, number of extension ports, and rank = 4 (second table in FIG. 37 ).

[0181] According to this embodiment, antenna port indication in case 3 of PUSCH can be performed appropriately.

[0182] <Embodiment #6> This embodiment relates to a new antenna port table for Case 4 of PUSCH.

[0183] The DMRS setting type may be 1, the maximum DMRS length may be 2, and the number of extension ports (number of DMRS ports) may be 24 (Case 4).

[0184] The antenna port indication field size (number of bits) may be increased so that the new antenna port table includes entries with DMRS CDM group numbers {4, 5, 6} without data. DMRS CDM group numbers 1, 2, 3, and 4 without data may refer to CDM groups {0}, {0, 1}, {0, 1, 2}, {0, 1, 2, 3}, {0, 1, 2, 3, 4}, and {0, 1, 2, 3, 4, 5}, respectively. The antenna port table may be defined to have all or some of the entries in the following example new antenna port table: 38 shows an example of a new antenna port table for DMRS configuration type 2, maximum DMRS length = 2, number of extension ports, and rank = 1. FIG. 39 shows an example of a new antenna port table for DMRS configuration type 2, maximum DMRS length = 2, number of extension ports, and rank = 2. FIG. 40 shows an example of a new antenna port table for DMRS configuration type 2, maximum DMRS length = 2, number of extension ports, and rank = 3. FIG. 41 shows an example of a new antenna port table for DMRS configuration type 2, maximum DMRS length = 2, number of extension ports, and rank = 4.

[0185] In these examples, the number of forward (DMRS) symbols may be 1 or 2. Some rows may be repeated with two values ​​(for the number of forward symbols).

[0186] According to this embodiment, antenna port indication in case 4 of PUSCH can be performed appropriately.

[0187] <Embodiment #7> This embodiment relates to the size (number of rows, field size, number of bits) of the new antenna port table / antenna port indication for PUSCH.

[0188] A new antenna port table may be defined that has some of the entries in the antenna port table of embodiments #3-6.

[0189] <<Embodiment 7A>> The new antenna port table does not need to include all rows for all port indexes in each CDM group for a certain value of the "number of DMRS CDM groups without data." The new antenna port table may only include at least one port index in each CDM group.

[0190] In the example antenna port table (FIG. 31) of embodiment #4, in which DMRS configuration type is 1, maximum DMRS length is 2, number of extension ports is 2, and rank is 1, rows with antenna port indication values ​​{5, 6, 7, 9, 10, 11, 13, 14, 15, 17, 18, 19, 21, 22, 23, 25, 26, 27, 29, 30, 31, 33, 34, 35, 37, 38, 39, ...} may be deleted. By maintaining one DMRS port per CDM group, the field size of the antenna port indication may be reduced.

[0191] <<Embodiment 7B>> The new antenna port table may not need to include rows with port indices spanning multiple CDM groups for certain values ​​of "Number of DMRS CDM groups without data." The new antenna port table may only maintain rows with all port indices within one CDM group (if the rank is not greater than the number of port indices per CDM group).

[0192] In the example antenna port table (FIG. 32) of embodiment #4, where DMRS configuration type is 1, maximum DMRS length is 2, number of extension ports is 2, and rank is 2, rows with antenna port indication values ​​{5, 6, 14, 15, 24, 25, 26, ...} may be deleted. By maintaining one DMRS port per CDM group, the field size of the antenna port indication may be reduced.

[0193] <<Embodiment 7C>> When the number of extended ports is configured, a new field may be added to the DCI to indicate whether the number of scheduled PDSCH / PUSCH exceeds a specific number. The specific number may be the number of existing CDM groups (supported number) for the configured case, or the maximum number of existing DMRS ports (supported number) for the configured case. A number of scheduled PDSCH / PUSCH exceeding the specific number may mean that the number of scheduled users of the MU is greater than the number of users supported in Rel. 15.

[0194] If the new field indicates that the number of scheduled PDSCH / PUSCHs does not exceed a certain number, the existing antenna port table may be used for antenna port indication.

[0195] If the new field indicates that the number of scheduled PDSCH / PUSCHs exceeds a certain number, a new antenna port table may be used for antenna port indication. In this manner, the new antenna port table may include only entries with more CDM groups or more DMRS ports than the existing number. For example, for case 1, the number of DMRS ports may be > 4; for case 2, the number of DMRS ports may be > 8; for case 3, the number of DMRS ports may be > 6; and for case 4, the number of DMRS ports may be > 12.

[0196] In an example of an antenna port table (Figure 31) for embodiment #4, DMRS setting type 1, maximum DMRS length = 2, number of extension ports, and rank = 1, rows with antenna port indication values ​​0 to 11 may be deleted.

[0197] In an example of an antenna port table (Figure 32) for embodiment #4, DMRS setting type 1, maximum DMRS length = 2, number of extension ports, and rank = 2, rows with antenna port indication values ​​0 to 7 may be deleted.

[0198] To reduce the size of the new antenna port table (the field size of the antenna port indication), at least two of embodiments #7A, #7B, and #7C may be combined.

[0199] According to this embodiment, the size of the antenna port indication / antenna port table can be reduced.

[0200] --Direction #2-2 The UE may reuse the existing antenna port table per list with a new implementation using new settings / instructions (embodiment #8).

[0201] <Embodiment #8> This embodiment relates to reusing the existing antenna port table for PUSCH.

[0202] This embodiment may assume that embodiment #0 is used.

[0203] A new field (list indication field) may be added to DCI format 0_1 / 0_2 (for scheduling the PUSCH) to indicate at least one of whether one list or two lists are applied to the scheduled PUSCH (the number of lists, the number of lists for rate matching) and a list index. For antenna port indication, an existing antenna port table may be reused for each list.

[0204] If the new field indicates one list, the existing antenna port table and DMRS port index for antenna port indication may be used. By default, the one list may be the first list. If the new field indicates one list, the UE may not transmit data on the REs indicated by the DMRS REs in the first list (and may perform rate matching around the REs indicated by the DMRS REs in the first list for its PUSCH). If the antenna port field indicates a row with the number x of CDM groups, not transmitting data on the REs indicated by the DMRS REs in the first list may mean rate matching on all DMRS ports in the x CDM groups in the first list.

[0205] The DCI (scheduling the PUSCH / PDSCH) may indicate whether data is mapped to REs not used for DMRS (similar to the "number of CDM groups without data" in Rel. 15). The number of CDM groups without data may be configured by higher layer signaling.

[0206] The number of lists may be configured by higher layer signaling. Other parameters such as the maximum number of DMRS ports and the maximum number of DMRS CDM groups may be configured by higher layer signaling, and the UE may determine the number of lists based on the parameters.

[0207] If one list is indicated, it may mean that a user multiplexed with the UE whose PUSCH / PDSCH is scheduled occupies only the DMRS ports in one list (list #1 by default). The UE may perform rate matching around the DMRS REs in one list. If two lists are indicated, it may mean that a user multiplexed with the UE whose PUSCH / PDSCH is scheduled occupies the DMRS ports in both lists. The UE may perform rate matching around the DMRS REs in both lists.

[0208] If the new field points to a list, the new field may include a list index. If the new field points to a list and a list index, the list may be the list corresponding to the list index.

[0209] If the new field points to two lists (lists #1 and #2), the new field may contain a list index.

[0210] If the list index indicates a second list, then in the antenna port table, the indicated DMRS port index j may be considered as DMRS port j+P, where P may be the maximum number of DMRS ports per list (maximum number). DMRS without data CDM group number {1,2,3} may refer to the CDM groups in the second list.

[0211] If the list index indicates the first list, the indicated DMRS port index j may be DMRS port j in the antenna port table. The DMRS CDM group number {1, 2, 3} without data may refer to the CDM group in the first list.

[0212] If the new field indicates two lists, the UE may not transmit data on the REs indicated by the DMRS REs in the two lists. The UE may follow either rate matching 1 or 2 below. [Rate Matching 1] The UE performs rate matching around the DMRS REs in all DMRS ports in the two lists. [Rate Matching 2] The UE performs rate matching around the DMRS REs in all DMRS ports in the first list and a DMRS port in the second list. An additional field (CDM Group Number field) may be added (to the DCI) to indicate the number of CDM groups in the second list for rate matching. The additional field may only be applied if the DMRS RE position of the jth port in the two lists is different. If the list index indicates the second list, no additional field is needed, and the UE may follow the Antenna Port field for the CDM Group Number for rate matching. If the list index indicates the first list, the additional field is valid and the UE may follow the indicated number of CDM groups for rate matching.

[0213] For example, the value of the new field may indicate the following: - A value of 00 may indicate one list for rate matching and an antenna port indication (in default list #1) for that DMRS. - A value of 01 may indicate two lists for rate matching and an antenna port indication in list #1 for that DMRS. - A value of 10 may indicate two lists for rate matching and an antenna port indication in list #2 for that DMRS. - A value of 11 may be reserved.

[0214] As a variation, a list index may be required even if only one list is indicated. For example, the value of the new field may indicate the following: - A value of 00 may indicate one list for rate matching and the antenna port indication in list #1 for that DMRS. - A value of 01 may indicate one list for rate matching and the antenna port indication in list #2 for that DMRS. - A value of 10 may indicate two lists for rate matching and the antenna port indication in list #1 for that DMRS. - A value of 11 may indicate two lists for rate matching and the antenna port indication in list #2 for that DMRS.

[0215] In embodiments #3 to #7, some new entries with DMRS port indexes in lists #1 and #2 may be introduced, which makes the indication more flexible.

[0216] For example, in the example of the legacy antenna port table ( FIG. 17 ) for PUSCH, DMRS configuration type 1, DMRS maximum length=1, and rank=1, the interpretation of the legacy antenna port table may be as follows: In list #1, the DMRS CDM group numbers 1 and 2 without data may refer to CDM groups {0} and {0,1}, respectively. In list #2, the DMRS CDM group numbers 1 and 2 without data may refer to CDM groups {2} and {2,3}, respectively, in list #2. If two lists are indicated and list #2 is indicated, port index j may refer to the j-th port in list #2. In case 1, port index j may be index j+P=j+4 in list #2. For list #2, DMRS ports 0, 1, 2, and 3 may be interpreted as DMRS ports 4, 5, 6, and 7, respectively.

[0217] According to this embodiment, the number of DMRS ports can be increased without changing the antenna port table.

[0218] Analysis #3: For PDSCH (similar to PUSCH), the antenna port indication in DCI format 1_1 / 1_2 may indicate a number of CDM groups > 2 for DMRS configuration type 1 and a number of CDM groups > 3 for DMRS configuration type 2.

[0219] The legacy antenna port table can only indicate a CDM group count of ≦2 for DMRS configuration type 1, and can only indicate a CDM group count of ≦3 for DMRS configuration type 2. Figure 42 shows an example of a legacy antenna port table for PDSCH, DMRS configuration type=1, and maximum DMRS length=1. Figure 43 shows an example of a legacy antenna port table for PDSCH, DMRS configuration type=1, and maximum DMRS length=2. Figure 44 shows an example of a legacy antenna port table for PDSCH, DMRS configuration type=2, and maximum DMRS length=1. Figure 45 shows an example of a legacy antenna port table for PDSCH, DMRS configuration type=2, and maximum DMRS length=2.

[0220] The antenna port indication in the existing DCI format 1_1 / 1_2 follows the existing DMRS port table. DMRS without data The CDM group numbers 1, 2, and 3 may refer to CDM groups {0}, {0,1}, and {0,1,2}, respectively.

[0221] The UE may receive a DCI (DCI format) containing a PDSCH resource allocation and a value for an antenna port indication (antenna port field), and control the transmission of DMRS based on the association between the value, the number of CDM groups, and the DMRS port.

[0222] The extension of the antenna port indication for PDSCH may follow either of the following directions #3-1 and #3-2.

[0223] --Direction #3-1 A new antenna port table may be defined for the following cases 1 to 4 (embodiment #9): [Case 1] DMRS setting type 1, maximum DMRS length = 1, number of ports = 8 [Case 2] DMRS setting type 1, maximum DMRS length = 2, number of ports = 16 [Case 3] DMRS setting type 2, maximum DMRS length = 1, number of ports = 12 [Case 4] DMRS setting type 2, maximum DMRS length = 2, number of ports = 24

[0224] <Embodiment #9> This embodiment relates to a new antenna port table for PDSCH.

[0225] Similar to embodiments #3-6, a new antenna port table for PDSCH may be defined.

[0226] Similar to embodiment #7, a new antenna port table may be defined that has some entries in the antenna port table for PDSCH based on embodiments #3-6.

[0227] <<Case 1>> The DMRS setting type may be 1, the maximum DMRS length may be 1, and the number of extension ports (number of DMRS ports) may be 8 (Case 1).

[0228] <<Assumption A>> Option 1 of embodiment #1 may be applied to two CDM groups for eight ports. Four existing antenna port tables for Case 1 may be reused for Case 1 with the extended number of ports. The field size (number of bits) of the antenna port indication may be increased to five bits.

[0229] <<Scenario B>> Option 2 of embodiment #1 may be applied to 4 CDM groups for 8 ports.

[0230] The field size (number of bits) of the antenna port indication may be increased so that the new antenna port table includes entries with DMRS CDM group numbers {3, 4} without data. DMRS CDM group numbers 1, 2, 3, and 4 without data may indicate CDM groups {0}, {0, 1}, {0, 1, 2}, and {0, 1, 2, 3}, respectively. The antenna port table may be defined to have all or some of the entries of the example new antenna port table in Figure 46 (DMRS configuration type 1, DMRS max length = 1, extended port number case).

[0231] <<Case 2>> The DMRS setting type may be 1, the maximum DMRS length may be 2, and the number of extension ports (number of DMRS ports) may be 16 (Case 2).

[0232] The field size (number of bits) of the antenna port indication may be increased so that the new antenna port table includes an entry with DMRS CDM group numbers {3, 4} without data. DMRS CDM group numbers 1, 2, 3, and 4 without data may indicate CDM groups {0}, {0, 1}, {0, 1, 2}, and {0, 1, 2, 3}, respectively. The antenna port table may be specified to have all or some of the entries of the example new antenna port table (DMRS configuration type 1, DMRS maximum length = 2, extended port number case) that combines the first part of Figure 47, the second part of Figure 48, and the third part of Figure 49.

[0233] The number of forward (DMRS) symbols may be 1 or 2. A row may be repeated using two rows that differ only in the number of forward symbols.

[0234] The new antenna port table for cases 3 / 4 is not illustrated because it would be large, but the same concept as for cases 1 / 2 may be used.

[0235] According to this embodiment, antenna port indication for PDSCH can be performed appropriately.

[0236] --Direction #3-2 The UE may reuse the existing antenna port table per list with a new implementation using new settings / instructions (embodiment #10).

[0237] <Embodiment #10> This embodiment relates to reusing the existing antenna port table for PDSCH.

[0238] As in embodiment #8, the existing antenna port table for PDSCH may be reused.

[0239] This embodiment may assume that embodiment #0 is used.

[0240] A new field (list indication field) may be added to DCI format 0_1 / 0_2 (for scheduling the PDSCH) to indicate at least one of whether one list or two lists are applied to the scheduled PDSCH (the number of lists, the number of lists for rate matching) and a list index. For antenna port indication, an existing antenna port table may be reused for each list.

[0241] If the new field indicates one list, the existing antenna port table and DMRS port index for antenna port indication may be used. By default, the one list may be the first list. If the new field indicates one list, the UE may not receive data on the REs indicated by the DMRS REs in the first list (and may perform rate matching around the REs indicated by the DMRS REs in the first list for the PDSCH). If the antenna port field indicates a row with the number x of CDM groups, not receiving data on the REs indicated by the DMRS REs in the first list may mean rate matching on all DMRS ports in the x CDM groups in the first list.

[0242] The DCI (scheduling the PUSCH / PDSCH) may indicate whether data is mapped to REs not used for DMRS (similar to the "number of CDM groups without data" in Rel. 15). The number of CDM groups without data may be configured by higher layer signaling.

[0243] The number of lists may be configured by higher layer signaling. Other parameters such as the maximum number of DMRS ports and the maximum number of DMRS CDM groups may be configured by higher layer signaling, and the UE may determine the number of lists based on the parameters.

[0244] If one list is indicated, it may mean that a user multiplexed with the UE whose PUSCH / PDSCH is scheduled occupies only the DMRS ports in one list (list #1 by default). The UE may perform rate matching around the DMRS REs in one list. If two lists are indicated, it may mean that a user multiplexed with the UE whose PUSCH / PDSCH is scheduled occupies the DMRS ports in both lists. The UE may perform rate matching around the DMRS REs in both lists.

[0245] If the new field points to a list, the new field may include a list index. If the new field points to a list and a list index, the list may be the list corresponding to the list index.

[0246] If the new field points to two lists (lists #1 and #2), the new field may contain a list index.

[0247] If the list index indicates a second list, then in the antenna port table, the indicated DMRS port index j may be considered as DMRS port j+P, where P may be the maximum number of DMRS ports per list (maximum number). DMRS without data CDM group number {1,2,3} may refer to the CDM groups in the second list.

[0248] If the list index indicates the first list, the indicated DMRS port index j may be DMRS port j in the antenna port table. The DMRS CDM group number {1, 2, 3} without data may refer to the CDM group in the first list.

[0249] If the new field indicates two lists, the UE may not receive data on the REs indicated by the DMRS REs in the two lists. The UE may follow either rate matching 1 or 2 below. [Rate Matching 1] The UE performs rate matching around the DMRS REs in all DMRS ports in the two lists. [Rate Matching 2] The UE performs rate matching around the DMRS REs in all DMRS ports in the first list and one DMRS port in the second list. An additional field (CDM Group Number field) may be added (to the DCI) to indicate the number of CDM groups in the second list for rate matching. The additional field may only be applied if the DMRS RE position of the jth port in the two lists is different. If the list index indicates the second list, no additional field is needed, and the UE may follow the Antenna Port field for the CDM Group Number for rate matching. If the list index indicates the first list, the additional field is valid and the UE may follow the indicated number of CDM groups for rate matching.

[0250] For example, the value of the new field may indicate the following: - A value of 00 may indicate one list for rate matching and an antenna port indication (in default list #1) for that DMRS. - A value of 01 may indicate two lists for rate matching and an antenna port indication in list #1 for that DMRS. - A value of 10 may indicate two lists for rate matching and an antenna port indication in list #2 for that DMRS. - A value of 11 may be reserved.

[0251] As a variation, a list index may be required even if only one list is indicated. For example, the value of the new field may indicate the following: - A value of 00 may indicate one list for rate matching and the antenna port indication in list #1 for that DMRS. - A value of 01 may indicate one list for rate matching and the antenna port indication in list #2 for that DMRS. - A value of 10 may indicate two lists for rate matching and the antenna port indication in list #1 for that DMRS. - A value of 11 may indicate two lists for rate matching and the antenna port indication in list #2 for that DMRS.

[0252] In embodiment #9, some new entries with DMRS port indexes in lists #1 and #2 may be introduced, which makes the indication more flexible.

[0253] For example, in the example of the legacy antenna port table (Figure 43) for PDSCH, DMRS configuration type 1, and DMRS max length = 1, the interpretation of the legacy antenna port table may be as follows: - In list #1, the DMRS CDM group numbers 1 and 2 without data may refer to CDM groups {0} and {0,1}, respectively. - In list #2, the DMRS CDM group numbers 1 and 2 without data may refer to CDM groups {2} and {2,3}, respectively, in list #2. - If two lists are indicated and list #2 is indicated, port index j may refer to the j-th port in list #2. In case 2, port index j may be index j+P=j+8 in list #2. For list #2, DMRS ports 0, 1, 2, and 3 may be interpreted as DMRS ports 4, 5, 6, and 7, respectively.

[0254] According to this embodiment, the number of DMRS ports can be increased without changing the antenna port table.

[0255] - Analysis #4 DMRS The number of CDM groups may not increase, but the number of DMRS ports per CDM group may increase.

[0256] The question is how to perform the mapping between DMRS ports and CDM groups. In the following embodiments, it is considered to use the existing mapping / order as much as possible.

[0257] The question arises as to how to use the legacy antenna port table / legacy DMRS port table for antenna port indication for PDSCH / PUSCH. In the following embodiment, consideration is given to using the legacy antenna port table / legacy DMRS port table as much as possible.

[0258] The UE may receive the DMRS configuration and control transmission and reception of DMRS based on one or more associations and configurations between the multiple CDM groups and the multiple DMRS ports. The number of DMRS ports for DMRS configuration type 1 may be more than 8, and the number of DMRS ports for DMRS configuration type 2 may be more than 12.

[0259] <Embodiment #11> This embodiment relates to mapping of CDM groups and DMRS ports.

[0260] A new concept of CDM group subset (group subset) may be introduced under the CDM group. The number of CDM groups per CDM group subset and the CDM group order may follow the existing DMRS port table. The CDM group subset may support at least one of the following cases 1 to 4.

[0261] [Case 1] Eight ports may be available. Two CDM groups may be available. There may be two group subsets per CDM group. Four DMRS ports may correspond to each CDM group. Group subsets #1 and #2 may each correspond to CDM group {0,1}.

[0262] [Case 2] 16 ports may be available. 2 CDM groups may be available. There may be 2 group subsets per CDM group. 8 DMRS ports may correspond to each CDM group. Group subsets #1 and #2 may each correspond to CDM group {0,1}.

[0263] [Case 3] 12 ports may be available. 3 CDM groups may be available. There may be 2 group subsets per CDM group. 4 DMRS ports may correspond to each CDM group. Group subsets #1 and #2 may each correspond to CDM groups {0, 1, 2}.

[0264] [Case 4] 24 ports may be available. 3 CDM groups may be available. There may be 2 group subsets per CDM group. 8 DMRS ports may correspond to each CDM group. Group subsets #1 and #2 may each correspond to CDM groups {0, 1, 2}.

[0265] For each group subset, the order of the CDM groups in the existing DMRS port table may be reused. For the second group subset, the DMRS port index j in the DMRS port table may refer to j+P, where P may be the number of DMRS ports in the group subset (the maximum number of DMRS ports in the group subset). For the first group subset, the DMRS port index j in the DMRS port table may refer to j.

[0266] Figure 50 shows an example of group subsets for Case 1. In the DMRS port table, DMRS ports {1000, 1001, 1002, 1003} correspond to CDM groups {0, 0, 1, 1}, respectively. The mapping for group subset #1 is as shown in the DMRS port table. The actual mapping for group subset #2 is achieved by applying P=4 to the DMRS port table, so that DMRS ports j+P={1004, 1005, 1006, 1007} ​​correspond to CDM groups {0, 0, 1, 1}, respectively.

[0267] Figure 51 shows an example of group subsets for Case 2. In the DMRS port table, DMRS ports {1000, 1001, 1002, 1003, 1004, 1005, 1006, 1007} ​​correspond to CDM groups {0, 0, 1, 1, 0, 0, 1, 1}, respectively. The mapping for group subset #1 is as shown in the DMRS port table. The actual mapping for group subset #2 is achieved by applying P=8 to the DMRS port table, so that DMRS ports j+P={1008, 1009, 1010, 1011, 1012, 1013, 1014, 1015} correspond to CDM groups {0, 0, 1, 1, 0, 0, 1, 1}, respectively.

[0268] Figure 52 shows an example of group subsets for Case 3. In the DMRS port table, DMRS ports {1000, 1001, 1002, 1003, 1004, 1005} correspond to CDM groups {0, 0, 1, 1, 2, 2}, respectively. The mapping for group subset #1 is as shown in the DMRS port table. The actual mapping for group subset #2 is achieved by applying P=6 to the DMRS port table, so that DMRS ports j+P={1006, 1007, 1008, 1009, 1010, 1011} correspond to CDM groups {0, 0, 1, 1, 2, 2}, respectively.

[0269] Figure 53 shows an example of group subsets for Case 4. In the DMRS port table, DMRS ports {1000, 1001, 1002, 1003, 1004, 1005, 1006, 1007, 1008, 1009, 1010, 1011} correspond to CDM groups {0, 0, 1, 1, 2, 2, 0, 0, 1, 1, 2, 2}, respectively. The mapping for group subset #1 is as follows in the DMRS port table. The actual mapping for group subset #2 is by applying P=12 to the DMRS port table, where DMRS ports j+P={1012, 1013, 1014, 1015, 1016, 1017, 1018, 1019, 1020, 1021, 1022, 1023} correspond to CDM groups {0, 0, 1, 1, 2, 2, 0, 0, 1, 1, 2, 2}, respectively.

[0270] According to this embodiment, the number of DMRS ports can be increased appropriately.

[0271] <Embodiment #12> This embodiment relates to reusing an existing antenna port table.

[0272] A new field (group subset indication field) may be added to DCI format 0_1 / 0_2 / 1_1 / 1_2 (for scheduling the PUSCH / PDSCH) to indicate at least one of whether one group subset or one group subset is applied to the scheduled PUSCH / PDSCH (the number of group subsets, the number of group subsets for rate matching) and a group subset index. For antenna port indication, an existing antenna port table may be reused for each group subset.

[0273] If the new field indicates one group subset, the existing antenna port table and the DMRS port index for the antenna port indication may be used. By default, the one group subset may be the first group subset. If the new field indicates one group subset, the UE may not transmit / receive data on the REs indicated by the DMRS REs in the first group subset (and may perform rate matching for the PUSCH / PDSCH around the REs indicated by the DMRS REs in the first group subset). If the antenna port field indicates a row with the number x of CDM groups, not transmitting / receiving data on the REs indicated by the DMRS REs in the first group subset may mean rate matching on all DMRS ports in the x CDM groups in the first group subset.

[0274] The DCI (scheduling the PUSCH / PDSCH) may indicate whether data is mapped to REs not used for DMRS (similar to the "number of CDM groups without data" in Rel. 15). The number of CDM groups without data may be configured by higher layer signaling.

[0275] The number of group subsets may be configured by higher layer signaling. Other parameters such as the maximum number of DMRS ports and the maximum number of DMRS CDM groups may be configured by higher layer signaling, and the UE may determine the number of group subsets based on the parameters.

[0276] If one group subset is indicated, it may mean that users multiplexed with the UE scheduled for that PUSCH / PDSCH occupy only DMRS ports in one group subset (group subset #1 by default). The UE may perform rate matching around the DMRS REs in one group subset. If two group subsets are indicated, it may mean that users multiplexed with the UE scheduled for that PUSCH / PDSCH occupy DMRS ports in two group subsets. The UE may perform rate matching around the DMRS REs in the two group subsets.

[0277] If the new field indicates one group subset, the new field may include a group subset index. If the new field indicates one group subset and a group subset index, the one group subset may be the group subset corresponding to the group subset index.

[0278] If the new field indicates two group subsets (group subsets #1 and #2), the new field may include a group subset index.

[0279] If the group subset index indicates a second group subset, then in the antenna port table, the indicated DMRS port index j may be considered as DMRS port j+P, where P may be the maximum number of DMRS ports per group subset (maximum number). DMRS without data CDM group number {1,2,3} may refer to the CDM groups in the second group subset.

[0280] If the group subset index indicates the first group subset, then in the antenna port table, the indicated DMRS port index j may be DMRS port j. DMRS without data CDM group number {1,2,3} may refer to the CDM groups in the first group subset.

[0281] If the new field indicates two group subsets, the UE may not transmit / receive data on the REs indicated by the DMRS REs in the two group subsets. The UE may follow either rate matching 1 or 2 below. [Rate Matching 1] The UE performs rate matching around the DMRS REs in all DMRS ports in the two group subsets. [Rate Matching 2] The UE performs rate matching around the DMRS REs in all DMRS ports in the first group subset and one DMRS port in the second group subset. An additional field (CDM Group Number field) may be added (to the DCI) to indicate the number of CDM groups in the second group subset for rate matching. The additional field may only be applied if the DMRS RE position of the jth port in the two group subsets is different. If the group subset index indicates the second group subset, no additional field is needed, and the UE may follow the Antenna Port field for the CDM Group Number for rate matching. If the group subset index indicates the first group subset, the additional field is valid and the UE may follow the indicated number of CDM groups for rate matching.

[0282] For example, the value of the new field may indicate the following: - A value of 00 may indicate one group subset for rate matching and antenna port indication (in default group subset #1) for that DMRS. - A value of 01 may indicate two group subsets for rate matching and antenna port indication in group subset #1 for that DMRS. - A value of 10 may indicate two group subsets for rate matching and antenna port indication in group subset #2 for that DMRS. - A value of 11 may be reserved.

[0283] As a variation, a group subset index may be required even if only one group subset is indicated. For example, the value of the new field may indicate the following: - A value of 00 may indicate one group subset for rate matching and antenna port indication within group subset #1 for that DMRS. - A value of 01 may indicate one group subset for rate matching and antenna port indication within group subset #2 for that DMRS. - A value of 10 may indicate two group subsets for rate matching and antenna port indication within group subset #1 for that DMRS. - A value of 11 may indicate two group subsets for rate matching and antenna port indication within group subset #2 for that DMRS.

[0284] In embodiments #3 to #7, some new entries with DMRS port indexes in group subsets #1 and #2 may be introduced, which makes the indication more flexible.

[0285] For example, in the example of the legacy antenna port table (FIG. 17) for DMRS configuration type 1, DMRS max length = 1, the interpretation of the legacy antenna port table may be as follows: DMRS without data CDM group numbers 1 and 2 may refer to CDM groups {0} and {0,1}, respectively. In group subset #1, CDM group 0 may correspond to DMRS port index {0,1}, and CDM group 1 may correspond to DMRS port index {2,3}. In group subset #2, CDM group 0 may correspond to DMRS port index {4,5}, and CDM group 1 may correspond to DMRS port index {6,7}. If two group subsets are indicated and group subset #2 is indicated, port index j may refer to the j-th port in group subset #2. Port index j may be index j+P=j+4 within group subset #2. For group subset #2, DMRS ports 0, 1, 2, and 3 may be interpreted as DMRS ports 4, 5, 6, and 7, respectively.

[0286] According to this embodiment, the number of DMRS ports can be increased without changing the antenna port table.

[0287] <Variations> This embodiment relates to variations applicable to embodiments #8 / #10 / #12.

[0288] In embodiments #8 / #10, the j-th DMRS port (port index j) in list #1 and the j-th DMRS port (port index j+P) in list #2 can occupy (be mapped to) the same DMRS RS.

[0289] In embodiment #12, the j-th DMRS port (port index j) in group subset #1 and the j-th DMRS port (port index j+P) in group subset #2 can occupy (be mapped to) the same DMRS RS.

[0290] In these situations, rate matching on the j-th DMRS port in one list / group subset may have the same effect as rate matching on the j-th DMRS port in two lists / group subsets. Rate matching on all DMRS ports in one list / group subset may have the same effect as rate matching on all DMRS ports in two lists / group subsets. In this case, the following variations may apply: - The indication of one list or two lists (one group subset or two group subsets) for rate matching may not be necessary. - A new indication (new field) may be introduced to indicate the list index / group subset index of the antenna port indication. The antenna port indication can be interpreted based on the list index / group subset index. - If the second list / group subset is indicated, the interpretation of the existing table may be the same as in embodiments #8 / #10 / #12. In embodiments #8 / #10, for the second list, the indicated DMRS port index j in the existing DMRS port table may be considered as DMRS port j+P, and the CDM group numbers 1, 2, and 3 without data may refer to the CDM groups in the second list. In embodiment #12, for the second group subset, the indicated DMRS port index j in the existing DMRS port table may be considered as DMRS port j+P. Rate matching may be the same as in existing specifications. If the antenna port field indicates a row with CDM group number x, it may mean rate matching on all DMRS ports in the x CDM groups.

[0291] <Other Embodiments> <UE Capability Information / Higher Layer Parameter> Higher layer parameters (RRC IEs) / UE capabilities corresponding to the functions (features) in each of the above embodiments may be defined. The higher layer parameters may indicate whether the functions are enabled. The UE capabilities may indicate whether the UE supports the functions.

[0292] A UE configured with higher layer parameters corresponding to the function may perform the function. It may also be specified that "a UE not configured with higher layer parameters corresponding to the function shall not perform the function (for example, in accordance with Rel. 15 / 16)."

[0293] A UE that has reported / transmitted a UE capability indicating that it supports the feature may perform the feature. It may also be specified that a UE that has not reported a UE capability indicating that it supports the feature shall not perform the feature (e.g., in accordance with Rel. 15 / 16).

[0294] If the UE reports / transmits a UE capability indicating that it supports the function and the corresponding higher layer parameters are configured, the UE may perform the function. It may also be specified that "if the UE does not report / transmit a UE capability indicating that it supports the function or if the corresponding higher layer parameters are not configured, the UE shall not perform the function (e.g., in accordance with Rel. 15 / 16)."

[0295] Which embodiment / option / choice / function is used among the above multiple embodiments may be configured by higher layer parameters, may be reported by the UE as a UE capability, may be specified in a specification, or may be determined by the reported UE capability and the configuration of higher layer parameters.

[0296] The UE capabilities may indicate whether the UE supports at least one of the following features: - More DMRS ports than in the existing specification (Rel. 15 / 16). - More DMRS ports for DMRS configuration type 1 or 2 or both. - More DMRS ports for DMRS mapping type A or B or both. - More DMRS ports for single symbol DMRS or single symbol DMRS and double symbol DMRS. - More DMRS ports for single symbol DMRS or double symbol DMRS.

[0297] The UE capability may indicate at least one of the following values: Number of DMRS ports.

[0298] The above UE capabilities / higher layer parameters allow the UE to achieve the above functions while maintaining compatibility with existing specifications.

[0299] (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.

[0300] 54 is a diagram showing an example of a schematic configuration of a wireless communication system according to an embodiment. The wireless communication system 1 may be a system that realizes communication using Long Term Evolution (LTE) specified by the Third Generation Partnership Project (3GPP), 5th generation mobile communication system New Radio (5G NR), or the like.

[0301] 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.

[0302] 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.

[0303] 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))).

[0304] 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.

[0305] 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).

[0306] 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.

[0307] 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.

[0308] 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.

[0309] 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.

[0310] The user terminal 20 may be a terminal that supports at least one of communication methods such as LTE, LTE-A, and 5G.

[0311] 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).

[0312] 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.

[0313] 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.

[0314] 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.

[0315] 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).

[0316] 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.

[0317] 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.

[0318] 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.

[0319] 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.

[0320] 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.

[0321] 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.

[0322] 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.

[0323] 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.

[0324] 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).

[0325] (Base Station) Fig. 55 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 there may be one or more of each of the control unit 110, the transceiver unit 120, the transceiver antenna 130, and the transmission line interface 140.

[0326] 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.

[0327] 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.

[0328] 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.

[0329] 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.

[0330] 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.

[0331] 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.

[0332] 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.

[0333] 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.

[0334] 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.

[0335] 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.

[0336] 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.

[0337] 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.

[0338] 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.

[0339] 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.

[0340] The transmission path interface 140 may transmit and receive signals (backhaul signaling) between devices included in the core network 30, other base stations 10, etc., and may acquire and transmit user data (user plane data), control plane data, etc. for the user terminal 20.

[0341] 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.

[0342] The transceiver 120 may transmit a demodulation reference signal (DMRS) configuration. The controller 110 may control transmission and reception of the DMRS based on one or more associations between a plurality of code division multiplexing (CDM) groups and a plurality of DMRS ports and the configuration. The number of the plurality of CDM groups for DMRS configuration type 1 may be greater than two, and the number of the plurality of CDM groups for DMRS configuration type 2 may be greater than three.

[0343] The transceiver 120 may transmit downlink control information including a resource allocation for the physical uplink shared channel and a value of the antenna port indication. The controller 110 may control reception of a code division multiplexing (CDM) group based on an association between the value, the number of CDM groups, and a demodulation reference signal (DMRS) port. The number of CDM groups for DMRS configuration type 1 may be greater than two, and the number of CDM groups for DMRS configuration type 2 may be greater than three.

[0344] The transceiver 120 may transmit downlink control information including a resource allocation for the physical downlink shared channel and a value of the antenna port indication. The transceiver 120 may control transmission of a code division multiplexing (CDM) group based on an association between the value, the number of CDM groups, and a demodulation reference signal (DMRS) port. The number of CDM groups for DMRS configuration type 1 may be greater than two, and the number of CDM groups for DMRS configuration type 2 may be greater than three.

[0345] The transceiver 120 may transmit a configuration of a demodulation reference signal (DMRS). The controller 110 may control transmission and reception of the DMRS based on one or more associations between a plurality of code division multiplexing (CDM) groups and a plurality of DMRS ports and the configuration. The number of the plurality of DMRS ports for DMRS configuration type 1 may be greater than 8, and the number of the plurality of DMRS ports for DMRS configuration type 2 may be greater than 12. The plurality of DMRS ports may include a first plurality of DMRS ports and a second plurality of DMRS ports.

[0346] (User terminal) Fig. 56 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.

[0347] 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.

[0348] 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.

[0349] 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.

[0350] 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.

[0351] 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.

[0352] 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.

[0353] 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.

[0354] 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.

[0355] 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.

[0356] 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.

[0357] 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.

[0358] 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.

[0359] 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.

[0360] 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.

[0361] 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.

[0362] 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.

[0363] The transceiver 220 may receive a demodulation reference signal (DMRS) configuration. The controller 210 may control transmission and reception of the DMRS based on one or more associations between a plurality of code division multiplexing (CDM) groups and a plurality of DMRS ports and the configuration. The number of the plurality of CDM groups for DMRS configuration type 1 may be greater than two, and the number of the plurality of CDM groups for DMRS configuration type 2 may be greater than three.

[0364] The plurality of CDM ports may include a first plurality of CDM groups and a second plurality of CDM groups. The plurality of DMRS ports may include a first plurality of DMRS ports and a second plurality of DMRS ports. The number of the plurality of DMRS ports for DMRS configuration type 1 may be greater than 8, and the number of the plurality of DMRS ports for DMRS configuration type 2 may be greater than 12.

[0365] The one or more associations may include a first association between the first plurality of CDM groups and the first plurality of DMRS ports, and a second association between the second plurality of CDM groups and the second plurality of DMRS ports.

[0366] The one or more associations may include a first association between the first plurality of CDM groups and the first plurality of DMRS ports, and the controller 210 may determine an index of one of the second plurality of DMRS ports by adding a first number to an index of one of the first plurality of DMRS ports, and the controller 210 may determine an index of one of the second plurality of CDM groups by adding a second number to an index of one of the first plurality of CDM groups.

[0367] The transceiver 220 may receive downlink control information including a resource allocation for the physical uplink shared channel and a value of the antenna port indication. The controller 210 may control transmission of a code division multiplexing (CDM) group based on an association between the value, the number of CDM groups, and a demodulation reference signal (DMRS) port. The number of CDM groups for DMRS configuration type 1 may be greater than two, and the number of CDM groups for DMRS configuration type 2 may be greater than three.

[0368] The number of DMRS ports for DMRS configuration type 1 may be greater than 8, and the number of DMRS ports for DMRS configuration type 2 may be greater than 12.

[0369] The association may include an association between an index of a CDM group and an index of the DMRS port.

[0370] A first plurality of DMRS ports may be associated with a first plurality of CDM groups, and a second plurality of DMRS ports may be associated with a second plurality of CDM groups. The controller 210 may determine an index of one of the second plurality of DMRS ports among the plurality of DMRS ports by adding a first number to an index of one of the first plurality of DMRS ports.

[0371] The transceiver 220 may receive downlink control information including a resource allocation for a physical downlink shared channel and an antenna port indication value. The controller 210 may control reception of a code division multiplexing (CDM) group based on an association between the value, the number of CDM groups, and a demodulation reference signal (DMRS) port. The number of CDM groups for DMRS configuration type 1 may be greater than two, and the number of CDM groups for DMRS configuration type 2 may be greater than three.

[0372] The number of DMRS ports for DMRS configuration type 1 may be greater than 8, and the number of DMRS ports for DMRS configuration type 2 may be greater than 12.

[0373] The association may include an association between an index of a CDM group and an index of the DMRS port.

[0374] A first plurality of DMRS ports may be associated with a first plurality of CDM groups, and a second plurality of DMRS ports may be associated with a second plurality of CDM groups. The controller 210 may determine an index of one of the second plurality of DMRS ports among the plurality of DMRS ports by adding a first number to an index of one of the first plurality of DMRS ports.

[0375] The transceiver 220 may receive a demodulation reference signal (DMRS) configuration. The controller 210 may control transmission and reception of the DMRS based on one or more associations between a plurality of code division multiplexing (CDM) groups and a plurality of DMRS ports and the configuration. The number of the plurality of DMRS ports for DMRS configuration type 1 may be greater than 8, and the number of the plurality of DMRS ports for DMRS configuration type 2 may be greater than 12. The plurality of DMRS ports may include a first plurality of DMRS ports and a second plurality of DMRS ports.

[0376] A first plurality of DMRS ports may be associated with the plurality of CDM groups, and a second plurality of DMRS ports may be associated with the plurality of CDM groups.

[0377] The controller 210 may determine an index of one of the second plurality of DMRS ports by adding a first number to an index of one of the first plurality of DMRS ports.

[0378] The control unit 210 may perform rate matching based on the setting.

[0379] (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.

[0380] 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.

[0381] For example, a base station, a user terminal, etc. according to an embodiment of the present disclosure may function as a computer that performs processing of the wireless communication method of the present disclosure. Figure 57 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.

[0382] 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.

[0383] 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.

[0384] 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.

[0385] 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.

[0386] 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.

[0387] 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.

[0388] 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.

[0389] 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.

[0390] 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).

[0391] 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.

[0392] 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.

[0393] (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.

[0394] 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.

[0395] 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.

[0396] 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.

[0397] 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.

[0398] 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.

[0399] 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.

[0400] 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.

[0401] 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.

[0402] 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.

[0403] 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.

[0404] 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.

[0405] 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.

[0406] 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.

[0407] 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.

[0408] 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.

[0409] 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.

[0410] 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.

[0411] 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."

[0412] 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.

[0413] 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.

[0414] 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.

[0415] 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.

[0416] 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.

[0417] 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.

[0418] 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.

[0419] 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).

[0420] 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).

[0421] 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).

[0422] 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.

[0423] 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.

[0424] 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).

[0425] In the present disclosure, terms such as "precoding," "precoder," "weight (precoding weight)," "Quasi-Co-Location (QCL)," "Transmission Configuration Indication state (TCI state)," "spatial relation," "spatial domain filter," "transmit power," "phase rotation," "antenna port," "antenna port group," "layer," "number of layers," "rank," "resource," "resource set," "resource group," "beam," "beam width," "beam angle," "antenna," "antenna element," "panel," etc. may be used interchangeably.

[0426] 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.

[0427] 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.

[0428] In this disclosure, the terms "Mobile Station (MS)," "user terminal," "User Equipment (UE)," "terminal," etc. may be used interchangeably.

[0429] 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.

[0430] 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.

[0431] 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.

[0432] 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.

[0433] 58 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, an axle 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.

[0434] 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.

[0435] 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).

[0436] 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.

[0437] 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.

[0438] 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.

[0439] 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.

[0440] 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.

[0441] 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).

[0442] 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.

[0443] 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)).

[0444] 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.

[0445] 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.

[0446] 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.

[0447] 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.

[0448] 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.

[0449] 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).

[0450] 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."

[0451] 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.

[0452] 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.

[0453] 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.

[0454] Also, "determination" may be considered to be "deciding" resolving, selecting, choosing, establishing, comparing, etc. In other words, "determination" may be considered to be "deciding" some action.

[0455] Furthermore, "judgment (decision)" may be read as "assuming," "expecting," "considering," or the like.

[0456] 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.

[0457] 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."

[0458] 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.

[0459] 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."

[0460] 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.

[0461] 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.

[0462] Although the invention according to the present disclosure has been described in detail above, it is clear to those skilled in the art that the invention according to the present disclosure is not limited to the embodiments described in the present disclosure. The invention according to the present disclosure can be implemented in modified and altered forms without departing from the spirit and scope of the invention as defined by the description of the claims. Therefore, the description of the present disclosure is intended to be illustrative and explanatory and does not impose any limiting meaning on the invention according to the present disclosure.

Claims

1. A receiver that receives higher layer signaling for setting a first extended demodulation reference signal (DMRS) setting type or a second extended DMRS setting type, and receives downlink control information (DCI) for scheduling a physical uplink shared channel (PUSCH), the DCI including an antenna port instruction; A control unit that controls transmission of the DMRS for the PUSCH based on an association between a number of code division multiplexing (CDM) groups and one or more DMRS ports corresponding to the value of the antenna port indication, A terminal, wherein two CDM groups are available when the first extended DMRS configuration type is configured, and three CDM groups are available when the second extended DMRS configuration type is configured, and each of the CDM groups includes a first group subset corresponding to four existing DMRS ports and a second group subset corresponding to four extended DMRS ports.

2. The terminal described in claim 1, wherein, when the rank is 2 or less, the one or more DMRS ports are one or more DMRS ports included in only one of the existing DMRS ports or the extended DMRS ports.

3. A terminal as described in claim 1, wherein the number of bits of the antenna port instruction is greater than the number of bits of the antenna port instruction when the higher layer signaling is not received.

4. A method for receiving a first enhanced demodulation reference signal (DMRS) configuration type or a second enhanced DMRS configuration type, comprising receiving higher layer signaling and receiving downlink control information (DCI) for scheduling a physical uplink shared channel (PUSCH), the DCI including an antenna port indication; and controlling transmission of the DMRS for the PUSCH based on an association between a number of Code Division Multiplexing (CDM) groups and one or more DMRS ports corresponding to the value of the antenna port indication; A wireless communication method for a terminal, wherein two CDM groups are available when the first extended DMRS configuration type is configured, and three CDM groups are available when the second extended DMRS configuration type is configured, and each of the CDM groups includes a first group subset corresponding to four existing DMRS ports and a second group subset corresponding to four extended DMRS ports.

5. A transmitter that transmits higher layer signaling for setting a first extended demodulation reference signal (DMRS) setting type or a second extended DMRS setting type, and transmits downlink control information (DCI) for scheduling a physical uplink shared channel (PUSCH), the DCI including an antenna port indication; A control unit that controls reception of the DMRS for the PUSCH based on an association between a number of code division multiplexing (CDM) groups and one or more DMRS ports corresponding to the value of the antenna port indication, A base station, wherein two CDM groups are available when the first extended DMRS configuration type is configured, and three CDM groups are available when the second extended DMRS configuration type is configured, and each of the CDM groups includes a first group subset corresponding to four existing DMRS ports and a second group subset corresponding to four extended DMRS ports.

6. A system having a terminal and a base station, The terminal includes: A receiver that receives higher layer signaling for configuring a first extended demodulation reference signal (DMRS) configuration type or a second extended DMRS configuration type, and receives downlink control information (DCI) for scheduling a physical uplink shared channel (PUSCH), the DCI including an antenna port indication; A control unit that controls transmission of the DMRS for the PUSCH based on an association between a number of code division multiplexing (CDM) groups and one or more DMRS ports corresponding to the value of the antenna port indication, The base station, A transmitter for transmitting the higher layer signaling and the DCI, A system, wherein two CDM groups are available when the first extended DMRS configuration type is configured, and three CDM groups are available when the second extended DMRS configuration type is configured, each of the CDM groups including a first group subset corresponding to four existing DMRS ports and a second group subset corresponding to four extended DMRS ports.