METHOD AND APPARATUS FOR PROVIDING DM-RS CONFIGURATION INFORMATION IN A WIRELESS COMMUNICATION SYSTEM

Abstract

The present invention relates to a method performed by a User Equipment (UE) in a wireless communication system, comprising: receiving Downlink Control Information (DCI) for a Physical Downlink Shared Channel (PDSCH) from a Base Station (BS); and receiving a demodulation reference signal (DM-RS) from the BS based on port information of the DM-RS included in the DCI, wherein the DM-RS port information identifies at least one DM-RS port from among DM-RS ports included in a first DM-RS port group and DM-RS ports included in a second DM-RS port group, and the DM-RS ports included in the second DM-RS port group are determined based on at least one offset from the DM-RS ports included in the first DM-RS port group.

Description

[Technical Field]

[0001] The present invention relates to a wireless communication system, and more particularly to a method and apparatus for providing DM-RS (Demodulation Reference Signal) configuration information in a wireless communication system. [Background technology]

[0002] Wireless communication systems have been widely deployed to provide various communication services such as voice and data. Generally, wireless communication systems are multiple access systems that can support communication with multiple users by sharing available system resources (e.g., bandwidth, transmit power, etc.). Examples of multiple access systems include code division multiple access (CDMA) systems, frequency division multiple access (FDMA) systems, time division multiple access (TDMA) systems, orthogonal frequency division multiple access (OFDMA) systems, and single carrier frequency division multiple access (SC-FDMA) systems. Summary of the Invention [Problem to be solved by the invention]

[0003] Based on the above discussion, the following will propose a method and apparatus for providing DM-RS configuration information in a wireless communication system.

[0004] The technical problems to be achieved by the present invention are not limited to the above-mentioned technical problems, and other technical problems not mentioned will be clearly understood by those skilled in the art to which the present invention pertains from the following description. [Means for solving the problem]

[0005] According to one aspect of the present invention, there is provided a method performed by a User Equipment (UE) in a wireless communication system, the method including: receiving Downlink Control Information (DCI) for a Physical Downlink Shared Channel (PDSCH) from a Base Station (BS); and receiving a demodulation reference signal (DM-RS) from the BS based on port information of the DM-RS included in the DCI, wherein the DM-RS port information identifies at least one DM-RS port from among DM-RS ports included in a first DM-RS port group and DM-RS ports included in a second DM-RS port group, and the DM-RS ports included in the second DM-RS port group are determined based on at least one offset from the DM-RS ports included in the first DM-RS port group.

[0006] In another aspect of the present invention, there is provided a user equipment (UE) in a wireless communication system. The user equipment includes at least one transceiver, at least one processor, and at least one computer memory operatively connected to the at least one processor and storing instructions that, when executed, cause the at least one processor to perform operations. The operations include receiving downlink control information (DCI) for a physical downlink shared channel (PDSCH) from a base station (BS), and receiving the PDSCH from the BS based on demodulation reference signal (DM-RS) port information included in the DCI, wherein the DM-RS port information identifies at least one DM-RS port from among DM-RS ports included in a first DM-RS port group and DM-RS ports included in a second DM-RS port group, and the DM-RS ports included in the second DM-RS port group are determined based on at least one offset from the DM-RS ports included in the first DM-RS port group.

[0007] In yet another aspect of the present invention, there is provided a processing device in a wireless communication system, the processing device including at least one processor and at least one computer memory operatively connectable to the at least one processor and storing instructions that, when executed, cause the at least one processor to perform operations for a user equipment (UE). The operations include receiving Downlink Control Information (DCI) for a Physical Downlink Shared Channel (PDSCH) from a base station (BS), and receiving the PDSCH from the BS based on demodulation reference signal (DM-RS) port information included in the DCI, wherein the DM-RS port information identifies at least one DM-RS port from among DM-RS ports included in a first DM-RS port group and DM-RS ports included in a second DM-RS port group, and the DM-RS ports included in the second DM-RS port group are determined based on at least one offset from the DM-RS ports included in the first DM-RS port group.

[0008] In yet another aspect of the present invention, a computer-readable storage medium is provided, the computer-readable storage medium storing at least one computer program including instructions that, when executed by at least one processor, cause the at least one processor to perform operations for a user equipment (UE), the operations including receiving Downlink Control Information (DCI) for a physical downlink shared channel (PDSCH) from a base station (BS) and receiving the PDSCH from the BS based on demodulation reference signal (DM-RS) port information included in the DCI, the DM-RS port information identifying at least one DM-RS port from among DM-RS ports included in a first DM-RS port group and DM-RS ports included in a second DM-RS port group, the DM-RS ports included in the second DM-RS port group being determined based on at least one offset from the DM-RS ports included in the first DM-RS port group.

[0009] In yet another aspect of the present invention, there is provided a method performed by a Base Station (BS) in a wireless communication system, comprising: transmitting Downlink Control Information (DCI) for a Physical Downlink Shared Channel (PDSCH) to a User Equipment (UE); and transmitting the PDSCH to the UE based on demodulation reference signal (DM-RS) port information included in the DCI, wherein the DM-RS port information indicates at least one DM-RS port from among DM-RS ports included in a first DM-RS port group and DM-RS ports included in a second DM-RS port group, and the DM-RS ports included in the second DM-RS port group are determined based on at least one offset from the DM-RS ports included in the first DM-RS port group.

[0010] In another aspect of the present invention, a base station (BS) is provided in a wireless communication system. The user equipment (UE) includes at least one transceiver, at least one processor, and at least one computer memory operatively connected to the at least one processor and storing instructions that, when executed, cause the at least one processor to perform operations. The operations include transmitting Downlink Control Information (DCI) for a Physical Downlink Shared Channel (PDSCH) to a User Equipment (UE), and transmitting the PDSCH to the UE based on demodulation reference signal (DM-RS) port information included in the DCI, wherein the DM-RS port information indicates at least one DM-RS port from among DM-RS ports included in a first DM-RS port group and DM-RS ports included in a second DM-RS port group, and the DM-RS ports included in the second DM-RS port group are determined based on at least one offset from the DM-RS ports included in the first DM-RS port group.

[0011] Preferably, the minimum value of the at least one offset is 0, and if the type of the DM-RS is a first type, the maximum value of the at least one offset is 8, and if the type of the DM-RS is a second type, the maximum value of the at least one offset is 12.

[0012] Preferably, when the number of DM-RS ports identified by the DM-RS port information is two or more, the DM-RS port information includes information regarding offsets corresponding to each of the two or more DM-RS ports.

[0013] Preferably, the DCI schedules a single codeword over the PDSCH, and the number of FL (Front-Loaded) symbols of the DM-RS is two.

[0014] Furthermore, the DCI includes information regarding the number of DM-RS CDM groups without data, and when the DCI schedules multiple codewords via the PDSCH or the number of FL (Front-Loaded) symbols of the DM-RS is 1, the number of DM-RS CDM groups without data of the DM-RS is twice the number of DM-RS CDM groups without data included in the DCI.

[0015] The above-described solutions to problems are merely some of the embodiments of the present invention, and various embodiments reflecting the technical features of the present invention will be understood and derived by those skilled in the art based on the detailed description of the present invention below. [Effects of the Invention]

[0016] According to the present invention, it is possible to efficiently transmit and receive radio signals in a radio communication system.

[0017] The effects obtained by the present invention are not limited to those mentioned above, and other effects not mentioned will be clearly understood by those skilled in the art from the following description. [Brief explanation of the drawings]

[0018] The accompanying drawings, which are included as part of the detailed description to aid in the understanding of embodiments of the present invention, provide examples of the invention and, together with the detailed description, explain embodiments of the invention.

[0019] [Figure 1] 1 is a diagram illustrating physical channels used in a 3GPP (registered trademark) system, which is an example of a wireless communication system, and a general signal transmission method using these channels. [Figure 2]FIG. 1 is a diagram illustrating the structure of a radio frame. [Figure 3] FIG. 1 illustrates a resource grid of slots. [Figure 4] FIG. 10 is a diagram illustrating an example of mapping physical channels within a slot. [Figure 5] FIG. 1 illustrates a PDSCH and ACK / NACK transmission process. [Figure 6] FIG. 1 illustrates a PUSCH transmission process. [Figure 7] FIG. 10 is a diagram illustrating an example of a DM-RS configuration type. [Figure 8] 10 is a flowchart illustrating a process for receiving a PDSCH according to the present disclosure. [Figure 9] 1 is a diagram illustrating a communication system 1 and wireless devices applicable to the present invention. [Figure 10] 1 is a diagram illustrating a communication system 1 and wireless devices applicable to the present invention. [Figure 11] 1 is a diagram illustrating a communication system 1 and wireless devices applicable to the present invention. [Figure 12] 1 is a diagram illustrating a communication system 1 and wireless devices applicable to the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0020] The following technologies can be used for various wireless access systems, such as code division multiple access (CDMA), frequency division multiple access (FDMA), time division multiple access (TDMA), orthogonal frequency division multiple access (OFDMA), and single carrier frequency division multiple access (SC-FDMA). CDMA can be implemented using radio technologies such as Universal Terrestrial Radio Access (UTRA) and CDMA2000. TDMA can be implemented using radio technologies such as Global System for Mobile communications (GSM), General Packet Radio Service (GPRS), and Enhanced Data Rates for GSM Evolution (EDGE). OFDMA can be implemented using radio technologies such as IEEE 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802-20, and Evolved UTRA (E-UTRA). UTRA is part of the Universal Mobile Telecommunications System (UMTS). 3GPP (3rd Generation Partnership Project) LTE (long term evolution) is a part of E-UMTS (Evolved UMTS) that uses E-UTRA, and LTE-A is an evolved version of 3GPP LTE. 3GPP NR (New Radio Access Technology) is an evolved version of 3GPP LTE / LTE-A.

[0021] As more communication devices require larger communication capacities, there is an emerging need for improved mobile broadband communication compared to existing radio access technologies (RATs). Furthermore, massive machine-type communications (MTC), which connects multiple devices and objects to provide various services anytime, anywhere, is one of the important issues to be considered in next-generation communications. Furthermore, communication system designs that take into account reliability- and latency-sensitive services / terminals are being discussed. Thus, the introduction of next-generation RATs that take into account enhanced mobile broadband communication (eMBB), massive MTC, and ultra-reliable and low latency communication (URLLC) is being discussed. For convenience, the present invention refers to these technologies as new radio or new RATs (NR).

[0022] For clarity of explanation, the description will be focused on 3GPP NR, but the technical idea of the present invention is not limited thereto.

[0023] In this specification, the term "setting" may be replaced with the term "configure / configuration," and the two terms may be used interchangeably. Conditional expressions (e.g., "if," "in a case," or "when") may be replaced with expressions such as "based on that" or "in a state / status." The operation or SW / HW configuration of a terminal / base station based on the satisfaction of a corresponding condition may be inferred or understood by analogy. In signal transmission and reception between wireless communication devices (e.g., base station, terminal), if the process on the receiving (or transmitting) side can be inferred or understood from the process on the transmitting (or receiving) side, the explanation may be omitted. For example, the signal determination / generation / encoding / transmission on the transmitting side may be understood as the signal monitoring / reception / decoding / decision on the receiving side. An expression that a terminal performs (or does not perform) a specific operation may also be interpreted as the base station operating by expecting / assuming (or expecting / assuming not) that the terminal will perform the specific operation. An expression that a base station performs (or does not perform) a specific operation can also be interpreted as a terminal operating under the expectation / assuming (or expecting / assuming not to perform) the execution of a specific operation of the base station. Furthermore, in the following description, divisions and indexes for each section, embodiment, example, option, method, solution, etc. are for the convenience of explanation and should not be interpreted as meaning that each necessarily constitutes an independent invention or that each necessarily must be implemented individually. Furthermore, in describing each section, embodiment, example, option, method, solution, etc., unless explicitly stated to conflict or contradict, it can be inferred / interpreted that at least some of them may be combined and implemented together, or at least some may be omitted and implemented.

[0024] In a wireless communication system, a terminal receives information from a base station via a downlink (DL), and transmits information from the base station via an uplink (UL). Information exchanged between the base station and the terminal includes data and various control information, and various physical channels exist depending on the type / purpose of the information exchanged.

[0025] FIG. 1 is a diagram illustrating physical channels used in a 3GPP system and a general signal transmission method using these channels.

[0026] A terminal that has been powered on in a powered-off state or that has newly entered a cell performs an initial cell search, such as establishing synchronization with a base station (S101). To this end, the terminal receives a synchronization signal block (SSB) from the base station. The SSB includes a primary synchronization signal (PSS), a secondary synchronization signal (SSS), and a physical broadcast channel (PBCH). The terminal establishes synchronization with the base station based on the PSS / SSS and obtains information such as a cell identity (ID). The terminal also obtains broadcast information within the cell based on the PBCH. In addition, during the initial cell search phase, the terminal can receive a downlink reference signal (DL RS) to check the status of the downlink channel.

[0027] After completing the initial cell search, the terminal receives a physical downlink control channel (PDCCH) and a physical downlink shared channel (PDSCH) corresponding to the physical downlink control channel to obtain more specific system information (S102).

[0028] Thereafter, the terminal performs a random access procedure to complete connection to the base station (S103 to S106). More specifically, the terminal transmits a preamble over a physical random access channel (PRACH) (S103) and receives a response message to the preamble over a physical downlink control channel (PRACH) and a corresponding physical downlink shared channel (S104). In the case of contention-based random access, the terminal performs a contention resolution procedure, such as transmitting a further physical random access channel (S105) and receiving a physical downlink control channel and a corresponding physical downlink shared channel (S106).

[0029] After performing this procedure, the terminal then receives a physical downlink control channel / physical downlink shared channel (S107) and transmits a physical uplink shared channel (PUSCH) / physical uplink control channel (PUCCH) (S108) as a general uplink / downlink signal transmission procedure. Control information transmitted by the terminal to the base station is referred to as uplink control information (UCI). UCI includes HARQ ACK / NACK (Hybrid Automatic Repeat and reQuest Acknowledgement / Negative-ACK), SR (Scheduling Request), CSI (Channel State Information), etc. CSI includes CQI (Channel Quality Indicator), PMI (Precoding Matrix Indicator), RI (Rank Indication), etc. UCI is generally transmitted via PUCCH, but may be transmitted via PUSCH when control information and traffic data need to be transmitted simultaneously. In addition, the UE may aperiodically transmit UCI via PUSCH at the request / instruction of the network.

[0030] FIG. 2 illustrates the structure of a radio frame. In NR, uplink and downlink transmissions are organized into frames. A radio frame has a length of 10 ms and is divided into two 5 ms half-frames (HF). A half-frame is divided into five 1 ms subframes (SF). A subframe is divided into one or more slots, and the number of slots in a subframe depends on the subcarrier spacing (SCS). Each slot contains 12 or 14 orthogonal frequency division multiplexing (OFDM) symbols depending on the cyclic prefix (CP). When a normal CP is used, each slot contains 14 OFDM symbols. When an extended CP is used, each slot contains 12 OFDM symbols.

[0031] Table 1 shows the number of OFDM symbols per slot (N slot symb ), number of slots per frame (N frame,u slot ) and the number of slots per subframe (N subframe,u slot )

[0032] [Table 1]

[0033] Table 2 shows the number of OFDM symbols per slot (N slot symb ), number of slots per frame (N frame,u slot ) and the number of slots per subframe (N subframe,u slot )

[0034] [Table 2]

[0035] The frame structure is illustrative only, and the number of subframes, slots, and symbols in a frame can vary.

[0036] In an NR system, OFDM numerology (e.g., SCS) can be configured to be different among multiple cells merged into one terminal. Accordingly, the (absolute time) duration of time resources (e.g., SF, slot, or TTI) (collectively referred to as TU (Time Unit) for convenience) consisting of the same number of symbols can be configured to be different among the merged cells. Here, the symbols include OFDM symbols (or CP-OFDM symbols) and SC-FDMA symbols (or Discrete Fourier Transform-spread-OFDM, DFT-s-OFDM symbols).

[0037] FIG. 3 illustrates a resource grid of a slot. One slot includes multiple symbols in the time domain. For example, in the case of a general CP, one slot includes 14 symbols, while in the case of an extended CP, one slot includes 12 symbols. A carrier includes multiple subcarriers in the frequency domain. A resource block (RB) is defined by multiple (e.g., 12) consecutive subcarriers in the frequency domain. A bandwidth part (BWP) is defined by multiple consecutive physical RBs (PRBs) in the frequency domain and can correspond to one numerology (e.g., SCS, CP length, etc.). A carrier includes up to N (e.g., 5) BWPs. Data communication is performed using activated BWPs, and only one BWP can be activated for one terminal. Each element in the resource grid is called a resource element (RE), and one modulation symbol can be mapped to it.

[0038] Figure 4 shows an example of mapping physical channels within a slot. PDCCH is transmitted in the DL control region, and PDSCH is transmitted in the DL data region. PUCCH is transmitted in the UL control region, and PUSCH is transmitted in the UL data region. GP provides a time gap when the base station and the terminal switch from transmission mode to reception mode or from reception mode to transmission mode. Some symbols at the time of switching from DL to UL within a subframe can be set as GP.

[0039] Each physical channel will be described in more detail below.

[0040] The PDCCH carries Downlink Control Information (DCI). For example, the PCCCH (i.e., DCI) carries the transmission format and resource allocation of the downlink shared channel (DL-SCH), resource allocation information for the uplink shared channel (UL-SCH), paging information for the Paging Channel (PCH), system information on the DL-SCH, resource allocation information for higher layer control messages such as voluntary access responses transmitted on the PDSCH, transmit power control commands, and activation / deactivation of configured scheduling (CS). The DCI includes a cyclic redundancy check (CRC), which is masked / scrambled with various identifiers (e.g., Radio Network Temporary Identifier, RNTI) depending on the owner or use of the PDCCH. For example, if the PDCCH is for a specific terminal, the CRC is masked with a terminal identifier (e.g., Cell-RNTI, C-RNTI). If the PDCCH is related to paging, the CRC is masked with a Paging-RNTI (P-RNTI). If the PDCCH is related to system information (e.g., System Information Block, SIB), the CRC is masked with a System Information RNTI (SI-RNTI). If the PDCCH is related to an voluntary access response, the CRC is masked with a Random Access RNTI (RA-RNTI).

[0041] The PDCCH consists of 1, 2, 4, 8, or 16 Control Channel Elements (CCEs) depending on the Aggregation Level (AL). A CCE is a logical allocation unit used to provide a PDCCH with a predetermined code rate according to the radio channel condition. A CCE consists of 6 Resource Element Groups (REGs). A REG is defined by one OFDM symbol and one (P)RB. The PDCCH is transmitted using a Control Resource Set (CORESET). A CORESET is defined by a set of REGs with a given pneumatic system (e.g., SCS, CP length, etc.). Multiple CORESETs for one UE can be overlapped in the time / frequency domain. A CORESET is configured by system information (e.g., Master Information Block, MIB) or UE-specific higher layer (e.g., Radio Resource Control, RRC, layer) signaling. Specifically, the number of RBs and the number of OFDM symbols (maximum 3) that make up a CORESET are configured by higher layer signaling.

[0042] To receive / detect the PDCCH, the UE monitors PDCCH candidates. PDCCH candidates indicate the CCEs that the UE should monitor for PDCCH detection. Each PDCCH candidate is defined by 1, 2, 4, 8, or 16 CCEs depending on the AL. Monitoring includes (blind) decoding of the PDCCH candidates. The set of PDCCH candidates that the UE monitors is defined as the PDCCH search space (SS). The search space includes a common search space (CSS) or a UE-specific search space (USS). The UE can obtain DCI by monitoring PDCCH candidates in one or more search spaces configured by MIB or higher layer signaling. Each CORESET is associated with one or more search spaces, and each search space is associated with one COREST. The search space is defined based on the following parameters:

[0043] - controlResourceSetId: Indicates the CORESET associated with the search space.

[0044] - monitoringSlotPeriodicityAndOffset: Indicates the PDCCH monitoring period (in slot units) and the PDCCH monitoring period offset (in slot units).

[0045] - monitoringSymbolsWithinSlot: indicates the PDCCH monitoring symbols within the slot (for example, indicates the first symbol of CORESET).

[0046] - nrofCandidates: indicates the number of PDCCH candidates (one of 0, 1, 2, 3, 4, 5, 6, 8) for each AL={1, 2, 4, 8, 16}.

[0047] *An opportunity (e.g., time / frequency resource) for monitoring a PDCCH candidate is defined as a PDCCH (monitoring) opportunity. One or more PDCCH (monitoring) opportunities are configured within a slot.

[0048] Table 3 illustrates the characteristics of each search space type.

[0049] [Table 3]

[0050] Table 4 illustrates DCI formats transmitted via the PDCCH.

[0051] [Table 4]

[0052] DCI format 0_0 is used to schedule a TB-based (or TB-level) PUSCH, and DCI format 0_1 is used to schedule a TB-based (or TB-level) PUSCH or a Code Block Group (CBG)-based (or CBG-level) PUSCH. DCI format 1_0 is used to schedule a TB-based (or TB-level) PDSCH, and DCI format 1_1 is used to schedule a TB-based (or TB-level) PDSCH or a CBG-based (or CBG-level) PDSCH (DL grant DCI). DCI formats 0_0 / 0_1 are referred to as UL grant DCI or UL scheduling information, and DCI formats 1_0 / 1_1 are referred to as DL grant DCI or DL scheduling information. DCI format 2_0 is used to convey dynamic slot format information (e.g., dynamic SFI) to a UE, and DCI format 2_1 is used to convey downlink pre-emption information to a UE. DCI format 2_0 and / or DCI format 2_1 are transmitted to terminals in a corresponding group via a group common PDCCH, which is a PDCCH transmitted to terminals defined in one group.

[0053] DCI format 0_0 and DCI format 1_0 are called fallback DCI formats, and DCI format 0_1 and DCI format 1_1 are called non-fallback DCI formats. The fallback DCI format maintains the same DCI size / field configuration regardless of the terminal settings. On the other hand, the non-fallback DCI format has different DCI size / field configurations depending on the terminal settings.

[0054] The PDSCH carries downlink data (e.g., DL-SCH transport block, DL-SCH TB) and uses modulation methods such as Quadrature Phase Shift Keying (QPSK), Quadrature Amplitude Modulation (16QAM), 64QAM, and 256QAM. The TB is encoded to generate a codeword. The PDSCH carries up to two codewords. Scrambling and modulation mapping are performed for each codeword, and the modulation symbols generated from each codeword are mapped to one or more layers. Each layer is mapped to resources along with a Demodulation Reference Signal (DMRS), generated as an OFDM symbol signal, and transmitted from the corresponding antenna port.

[0055] The PUCCH carries Uplink Control Information (UCI), which includes:

[0056] - SR (Scheduling Request): Information used to request UL-SCH resources.

[0057] - HARQ-ACK: A response to a downlink data packet (e.g., a codeword) on the PDSCH. It indicates whether the downlink data packet has been successfully received. One HARQ-ACK bit is transmitted in response to a single codeword, and two HARQ-ACK bits are transmitted in response to two codewords. HARQ-ACK responses include positive ACK (simply referred to as ACK), negative ACK (hereinafter referred to as NACK), DTX (Discontinuous Transmission), or NACK / DTX. Here, the term HARQ-ACK is used interchangeably with HARQ ACK / NACK and ACK / NACK.

[0058] CSI (Channel State Information): Feedback information for a downlink channel. MIMO (Multiple Input Multiple Output)-related feedback information includes a Rank Indicator (RI) and a Precoding Matrix Indicator (PMI).

[0059] Table 5 shows an example of a PUCCH format. According to the PUCCH transmission length, it can be divided into Short PUCCH (formats 0 and 2) and Long PUCCH (formats 1, 3, and 4).

[0060] [Table 5]

[0061] PUCCH format 0 carries UCI with a maximum size of 2 bits and is mapped and transmitted based on a sequence. Specifically, the terminal transmits one of multiple sequences over a PUCCH with PUCCH format 0 to transmit specific UCI to the base station. The terminal transmits a PUCCH with PUCCH format 0 within the PUCCH resource for the corresponding SR setting only when transmitting a positive SR.

[0062] PUCCH format 1 carries UCI with a maximum size of 2 bits, and modulation symbols are spread in the time domain by an orthogonal cover code (OCC) (which is set differently depending on whether frequency hopping is enabled or disabled). DMRS is transmitted in symbols where no modulation symbols are transmitted (i.e., it is transmitted using TDM (Time Division Multiplexing)).

[0063] PUCCH format 2 carries UCI with a bit size greater than 2 bits, and modulation symbols are transmitted using frequency division multiplexing (FDM) with DM-RS. DM-RS is located at symbol indices #1, #4, #7, and #10 within a 1 / 3 density resource block. A pseudo noise (PN) sequence is used for the DM-RS sequence. Frequency hopping can be enabled for the 2-symbol PUCCH format 2.

[0064] In PUCCH format 3, terminals are not multiplexed within the same physical resource block and UCI with a bit size greater than 2 bits is carried. That is, the PUCCH resources of PUCCH format 3 do not include orthogonal cover codes. Modulation symbols are transmitted using DMRS and TDM (Time Division Multiplexing).

[0065] PUCCH format 4 supports multiplexing of up to four UEs in the same physical resource block and carries UCI with a bit size greater than 2. That is, the PUCCH resource of PUCCH format 3 includes an orthogonal cover code. Modulation symbols are transmitted using DMRS and TDM (Time Division Multiplexing).

[0066] At least one of the one or more configured cells can be configured for PUCCH transmission in the UE. At least a primary cell can be configured as a cell for PUCCH transmission. At least one PUCCH cell group is configured in the UE based on the at least one cell configured for PUCCH transmission, and each PUCCH cell group includes one or more cells. A PUCCH cell group is also simply referred to as a PUCCH group. PUCCH transmission is configured not only for the primary cell but also for SCells, and the primary cell belongs to the primary PUCCH group, and the PUCCH-SCell configured for PUCCH transmission belongs to a secondary PUCCH group. The PUCCH on the primary cell is used for cells belonging to the primary PUCCH group, and the PUCCH on the PUCCH-SCell is used for cells belonging to the secondary PUCCH group.

[0067] The PUSCH carries uplink data (e.g., UL-SCH transport block, UL-SCH TB) and / or uplink control information (UCI) and is transmitted based on a cyclic prefix-orthogonal frequency division multiplexing (CP-OFDM) waveform or a discrete fourier transform-spread-orthogonal frequency division multiplexing (DFT-s-OFDM) waveform. When the PUSCH is transmitted based on the DFT-s-OFDM waveform, the terminal applies transform precoding to transmit the PUSCH. For example, if transform precoding is not possible (e.g., transform precoding is disabled), the terminal transmits the PUSCH based on the CP-OFDM waveform, and if transform precoding is possible (e.g., transform precoding is enabled), the terminal transmits the PUSCH based on the CP-OFDM waveform or the DFT-s-OFDM waveform. PUSCH transmissions are dynamically scheduled by UL grants in the DCI or semi-statically scheduled (configured grant) based on higher layer (e.g., RRC) signaling (and / or Layer 1 (L1) signaling (e.g., PDCCH)). PUSCH transmissions can be codebook-based or non-codebook-based.

[0068] 5 is a diagram illustrating an ACK / NACK transmission process. Referring to FIG. 5, a UE can detect a PDCCH in slot #n. Here, the PDCCH includes downlink scheduling information (e.g., DCI format 1_0, 1_1), and the PDCCH indicates a DL assignment-to-PDSCH offset (K0) and a PDSCH-HARQ-ACK reporting offset (K1). For example, DCI formats 1_0, 1_1 include the following information:

[0069] - Frequency domain resource assignment: Indicates the RB set assigned to the PDSCH.

[0070] Time domain resource assignment: Indicates K0 (e.g., slot offset), the starting position of the PDSCH within slot #n+K0 (e.g., OFDM symbol index) and the length of the PDSCH (e.g., number of OFDM symbols).

[0071] - PDSCH-to-HARQ_feedback timing indicator: Indicates K1.

[0072] - HARQ process number (4 bits): Indicates the HARQ process ID (Identity) for data (e.g., PDSCH, TB).

[0073] - PUCCH resource indicator (PRI): Indicates the PUCCH resource used for UCI transmission from among multiple PUCCH resources in a PUCCH resource set.

[0074] Thereafter, the UE receives the PDSCH from slot #(n+K0) according to the scheduling information of slot #n, and then transmits UCI via the PUCCH in slot #(n1+K1) after finishing receiving the PDSCH in slot #n1 (where n+K0≦n1). Here, the UCI includes a HARQ-ACK response to the PDSCH. For convenience, in FIG. 5, it is assumed that the SCS for the PDSCH and the SCS for the PUCCH are the same and that slot #n1 = slot #n+K0, but the present invention is not limited to this. If the SCSs are different, K1 is indicated / interpreted based on the SCS of the PUCCH.

[0075] If the PDSCH is configured to transmit a maximum of one TB, the HARQ-ACK response consists of 1 bit. If the PDSCH is configured to transmit a maximum of two TBs, the HARQ-ACK response consists of 2 bits if spatial bundling is not configured, and 1 bit if spatial bundling is configured. If the transmission time of the HARQ-ACK for multiple PDSCHs is specified as slot #(n+K1), the UCI transmitted in slot #(n+K1) includes the HARQ-ACK responses for multiple PDSCHs.

[0076] Whether a UE should perform spatial bundling for HARQ-ACK responses can be configured for each cell group (e.g., RRC / higher layer signaling). For example, spatial bundling is configured individually for each HARQ-ACK response transmitted via a PUCCH and / or a HARQ-ACK response transmitted via a PUSCH.

[0077] Spatial bundling is supported when the maximum number of TBs (or codewords) that can be received at one time (or scheduled by 1 DCI) in the serving cell is two (or more than two) (e.g., when the upper layer parameter maxNrofCodeWordsScheduledByDCI is equal to 2-TB). On the other hand, for 2-TB transmission, more than four layers are used, and for 1-TB transmission, up to four layers are used. As a result, when spatial bundling is configured for the cell group, spatial bundling is performed on serving cells in the cell group that can schedule more than four layers. A UE that wishes to transmit a HARQ-ACK response via spatial bundling in the serving cell can generate a HARQ-ACK response by performing a bit-wise logical AND operation on A / N bits for multiple TBs.

[0078] For example, assuming that a terminal receives DCI scheduling 2-TB and receives 2-TB via PDSCH based on the DCI, a terminal performing spatial bundling can generate a single A / N bit by logically ANDing the first A / N bit for the first TB and the second A / N bit for the second TB. As a result, if both the first TB and the second TB are ACK, the terminal reports an ACK bit value to the base station, and if any one of the TBs is NACK, the terminal reports a NACK bit value to the base station.

[0079] For example, if only 1-TB is actually scheduled on a serving cell that is configured to receive 2-TB, the terminal can logically AND the A / N bit for that 1-TB with a bit value of 1 to generate a single A / N bit. As a result, the terminal reports the A / N bit for 1-TB to the base station as is.

[0080] A base station / UE has multiple parallel DL HARQ processes for DL transmission. Multiple parallel HARQ processes enable continuous DL transmission while waiting for HARQ feedback for successful or unsuccessful reception of previous DL transmission. Each HARQ process is associated with a HARQ buffer in the Medium Access Control (MAC) layer. Each DL HARQ process manages state variables related to the number of transmissions of MAC Physical Data Blocks (PDUs) in the buffer, HARQ feedback for MAC PDUs in the buffer, the current redundancy version, etc. Each HARQ process is distinguished by a HARQ process ID.

[0081] 6 illustrates a PUSCH transmission process. Referring to FIG. 6, a UE can detect a PDCCH in slot #n. Here, the PDCCH includes uplink scheduling information (e.g., DCI formats 0_0 and 0_1). DCI formats 0_0 and 0_1 include the following information:

[0082] - Frequency domain resource assignment: Indicates the RB set assigned to the PUSCH.

[0083] - Time domain resource assignment: Indicates the slot offset K2, the starting position (e.g., symbol index) and length (e.g., number of OFDM symbols) of the PUSCH within the slot. The starting symbol and length are indicated by the SLIV (Start and Length Indicator Value) or are indicated separately.

[0084] Thereafter, the UE can transmit a PUSCH in slot #(n+K2) according to the scheduling information of slot #n, where the PUSCH includes the UL-SCH TB.

[0085] QCL (quasi-co location)

[0086] Two antenna ports are quasi-colocated if the channel properties of one antenna port can be inferred from the channel of the other antenna port. The channel properties include one or more of the following: delay spread, Doppler spread, frequency / Doppler shift, average received power, received timing / average delay, and spatial RX parameters.

[0087] A list of multiple TCI-State configurations is configured in the terminal by the higher layer parameter PDSCH-Config. Each TCI-State is associated with QCL configuration parameters between one or two DL reference signals and the DM-RS port of the PDSCH. The QCL includes qcl-Type1 for the first DL RS and qcl-Type2 for the second DL RS. The QCL type corresponds to one of the following:

[0088] - 'QCL-TypeA':{Doppler shift, Doppler spread, average delay, delay spread}

[0089] - 'QCL-TypeB':{Doppler shift, Doppler spread}

[0090] -'QCL-TypeC':{Doppler shift, average delay}

[0091] -'QCL-TypeD':{Spatial Rx parameter}

[0092] Beam Management (BM)

[0093] The BM process is a process for obtaining and maintaining a set of BS (or transmission and reception point (TRP)) and / or UE beams that can be used for downlink (DL) and uplink (UL) transmission / reception, and includes the following processes and terms:

[0094] - Beam measurement: An operation in which a BS or UE measures the characteristics of a received beamforming signal.

[0095] - Beam determination: The operation by which a BS or a UE selects its own transmit beam (Tx beam) / receive beam (Rx beam).

[0096] Beam sweeping: The operation of covering a spatial domain using transmit and / or receive beams in a predetermined manner for a certain time period.

[0097] - Beam report: An operation in which the UE reports information about beamformed signals based on beam measurements.

[0098] The BM process is divided into (1) a DL BM process using SSB or CSI-RS and (2) a UL BM process using SRS (Sounding Reference Signal). Each BM process includes Tx beam sweeping to determine the Tx beam and Rx beam sweeping to determine the Rx beam.

[0099] In this case, the DL BM process includes: (1) transmission of a beamformed DL RS (e.g., CSI-RS or SSB) by the BS; and (2) beam reporting by the UE.

[0100] Here, the beam report includes a preferred DL RS ID and its corresponding reference signal received power (RSRP). The DL RS ID is an SSB Resource Indicator (SSBRI) or a CSI-RS Resource Indicator (CRI).

[0101] RS related to MIMO (Multi-Input Multi-Output) operation

[0102] Among the RSs related to MIMO operation, DM-RS (demodulation reference signal) will be described below.

[0103] In NR, DM-RS is characterized by being transmitted only when necessary to enhance network energy efficiency and ensure forward compatibility. The time domain density of DM-RS varies depending on the speed or mobility of the terminal. That is, in NR, the density for DM-RS can be increased in the time domain to track rapid changes in the wireless channel.

[0104] (1) DM-RS reception procedure

[0105] The operation related to the DM-RS for receiving the PDSCH will be described.

[0106] When receiving a PDSCH scheduled by DCI format 1_0, or when receiving a PDSCH before configuring any dedicated higher layer among the parameters DM-RS-AdditionalPosition, maxLength, and DM-RS-Type, the terminal assumes that there is no PDSCH in any symbol carrying a DM-RS except for a PDSCH having an allocation duration of 2 symbols with PDSCH mapping type B, that a single-symbol front-loaded DM-RS with configuration type 1 is transmitted on DM-RS port 1000, and that all remaining orthogonal antenna ports are not associated with transmitting a PDSCH to other terminals. Furthermore,

[0107] - For PDSCH with mapping type A, the terminal assumes that there are DM-RS-AdditionalPosition='pos2' and up to two additional single-symbol DM-RSs in the slot according to the PDSCH duration indicated in the DCI.

[0108] For a PDSCH with an allocation duration of 7 symbols for a normal CP or 6 symbols for an extended CP with mapping type B, when a front-loaded DM-RS symbol is in the 1st or 2nd symbol of the PDSCH allocation duration, respectively, the terminal shall assume that one additional single-symbol DM-RS is present in the 5th or 6th symbol. Otherwise, the terminal shall assume that no additional DM-RS symbol is present.

[0109] For a PDSCH having an allocation duration of 4 symbols with mapping type B, the terminal assumes that no additional DM-RS exists,

[0110] For a PDSCH with an allocation duration of 2 symbols with mapping type B, the terminal assumes that no additional DM-RS is present, and the terminal assumes that the PDSCH is present within a symbol carrying a DM-RS.

[0111] When receiving a PDSCH scheduled by DCI format 1_1 via a PDCCH having a CRC scrambled by a C-RNTI, an MCS-C-RNTI, or a CS (configured scheduling)-RNTI,

[0112] The UE may be configured with an upper layer parameter DM-RS-Type, and the configured DM-RS configuration type is used to receive the PDSCH.

[0113] The UE may be configured with the maximum number of front-loaded DM-RS symbols for the PDSCH according to the upper layer parameter maxLength provided by DM-RS-DownlinkConfig.

[0114] The terminal can be scheduled with the number of DM-RS ports according to the antenna port index of DCI format 1_1.

[0115] 7 shows an example of DM-RS configuration types, in particular, FIG. 7(a) shows a type 1 DM-RS and FIG. 7(b) shows a type 2 DM-RS.

[0116] Type 1 DM-RS has higher RS density in the frequency domain and supports up to 4 (8) ports for single (double)-symbol DM-RS. Type 1 DM-RS also supports length 2 F-CDM and FDM for single-symbol DM-RS and length 2 F / T-CDM and FDM for double-symbol DM-RS. Type 2 DM-RS supports more DM-RS antenna ports and supports up to 6 (12) ports for single (double)-symbol DM-RS.

[0117] For Type 1 DM-RS, if a terminal is scheduled with one codeword and the antenna port mapping is assigned an index of {2, 9, 10, 11, or 30}, or if the terminal is scheduled with two codewords, the terminal may assume that none of the remaining orthogonal antenna ports are associated with transmitting PDSCH to other terminals.

[0118] For Type 2 DM-RS, if a terminal is scheduled with one codeword and the antenna port mapping is assigned an index of {2, 10, 23}, or if the terminal is scheduled with two codewords, the terminal may assume that none of the remaining orthogonal antenna ports are associated with transmitting PDSCH to other terminals.

[0119] (2) DM-RS transmission procedure

[0120] The DM-RS-related operations for PUSCH reception will now be described. The DM-RS transmission operations are similar to the DM-RS reception operations described above, except that the names of the DL-related parameters are replaced with the names of the UL-related parameters.

[0121] DM-RS (demodulation reference signal) setting instruction

[0122] When a UE receives a PDSCH scheduled by DCI, the UE is configured with a DM-RS configuration type by an upper layer parameter DM-RS-Type, and the DM-RS type is used to receive the PDSCH. In addition, the UE is configured with a maximum number of front-loaded (FL) DM-RS symbols to be inserted forward for the PDSCH by an upper layer parameter maxLength.

[0123] For Type 1 DM-RS, the terminal assumes that if a single codeword is scheduled and a DM-RS antenna port mapped with an index of {2, 9, 10, 11, or 30} is specified, or if two codewords are scheduled, the remaining orthogonal DM-RS antenna ports are also not associated with PDSCH transmission to other terminals.

[0124] Alternatively, in the case of Type 2 DM-RS, the terminal assumes that if a single codeword is scheduled and a DM-RS antenna port mapped with an index of {2, 10, or 23} is specified, or if two codewords are scheduled, all remaining orthogonal DM-RS antenna ports are also not involved in PDSCH transmission to other terminals.

[0125] According to the current 3GPP NR standard, for a Type 1 DM-RS with 2 FL (front loaded) symbols, there are a total of eight DM-RS antenna ports, from DM-RS antenna port 0 to DM-RS antenna port 7, and a combination of DM-RS antenna ports consisting of a subset of the eight DM-RS antenna ports (i.e., DM-RS antenna port 0 to DM-RS antenna port 7) is indicated via the DM-RS antenna port indicator table / field of the DCI.

[0126] Meanwhile, in 3GPP NR Standard Release 18, in addition to DM-RS antenna port 0 to DM-RS antenna port 7, DM-RS antenna port 8 to DM-RS antenna port 15 are added, bringing the total number of 16 DM-RS antenna ports to 16. Therefore, if the conventional DM-RS antenna port indicator table / field is used as is, only DM-RS antenna port 0 to DM-RS antenna port 7 can be indicated, and the added DM-RS antenna port 8 to DM-RS antenna port 15 cannot be indicated, which is a problem.

[0127] In the present disclosure, when the number of orthogonal DM-RS antenna ports is doubled compared to the conventional method, a method is proposed in which the DM-RS antenna ports are indicated by DCI.

[0128] Although the proposed method described below is based on downlink DM-RS antenna port indication, a similar method can also be applied to uplink DM-RS antenna port indication. However, since the uplink DM-RS antenna port indication is determined for each rank indicated by an SRS Resource Indicator (SRI) or a Precoding Matrix Index (PMI), the downlink DM-RS antenna port indicator table proposed in this disclosure can be configured with only the DM-RS antenna port indicator value of the corresponding rank.

[0129] <Proposal 1>

[0130] In Proposal 1 of the present disclosure, the DM-RS antenna port can be indicated by adding an offset f to the DM-RS antenna port combination for each value defined in the conventional DM-RS antenna port indicator table. Although Proposal 1 described below is based on Type 1 DM-RS, the proposed method can be applied regardless of the DM-RS type.

[0131] The base station may set the value of f differently for each UE and may indicate it by RRC / MAC CE / DCI. In addition, for a Type 1 DM-RS, the value of f may be indicated to at least one value in the range of 0 to 8, and for a Type 2 DM-RS, the value of f may be indicated to at least one value in the range of 0 to 12.

[0132] A conventional DM-RS indicator table will be taken as an example.

[0133] Table 6 illustrates a conventional DM-RS indicator table for a Type 1 DM-RS where the maximum number of FL (Front-Loaded) DM-RS symbols is two.

[0134] [Table 6]

[0135] When the value 20 (i.e., rank 2, DM-RS antenna port 0 and DM-RS antenna port 1) is indicated by the conventional DM-RS indicator table in Table 6, the UE interprets this as indicating DM-RS antenna port 0+f and DM-RS antenna port 1+f. When UE1 is set to an offset of 0, UE1 continues to use the conventional DM-RS indicator table, and DM-RS antenna port indication is performed for a subset of DM-RS antenna port 0 through DM-RS antenna port 7. In other words, when the value 20 is indicated, UE1 interprets this as indicating the conventional value, rank 2, and DM-RS antenna port 0 and DM-RS antenna port 1.

[0136] On the other hand, an offset of 8 is set for UE2, and DM-RS antenna port indication is made for a subset of DM-RS antenna port 8 through DM-RS antenna port 15. For example, if a value of 20 is indicated, UE2 adds 8 to each DM-RS antenna port, giving a rank of 2, and interprets this as indicating DM-RS antenna port 8 and DM-RS antenna port 9.

[0137] As a result, a UE for which an offset of 0 is specified is MU (multi-user)-MIMO scheduled using DM-RS antenna port 0 through DM-RS antenna port 7, and a UE for which an offset of 8 is specified is MU-MIMO scheduled using DM-RS antenna port 8 through DM-RS antenna port 15. Furthermore, both a UE for which an offset of 0 is specified and a UE for which an offset of 8 is specified are MU-MIMO scheduled, in this case using DM-RS antenna port 0 through DM-RS antenna port 15.

[0138] In the proposed scheme, the DM-RS indicator value to which an offset is applied can only be applied when there are 2 FL symbols and / or when only codeword 0 is enabled. When there is 1 FL symbol, the number of orthogonal DM-RS antenna ports is only four. Even if a new DM-RS pattern is introduced in 3GPP NR Standard Release 18 to double the number of DM-RS antenna ports, the number is still eight, the same as the number of DM-RS antenna ports for the conventional 2 FL symbols. Therefore, there is no reason or benefit to introduce a new DM-RS pattern, and therefore, application of an offset is unnecessary. When both codeword 0 and codeword 1 are enabled, this is a high rank case from the perspective of each UE (i.e., from the perspective of a single user (SU)). However, since MU MIMO is mainly used when the rank of each UE is low, there is little reason or benefit to use a new DM-RS pattern.

[0139] In Proposal 1, a common offset is applied regardless of the value of the DM-RS indicator table, so that a UE configured with Type 1 DM-RS offset 0 performs DM-RS indication within DM-RS antenna port 0 through DM-RS antenna port 7, and a UE configured with Type 1 DM-RS offset 8 performs indication within DM-RS antenna port 8 through DM-RS antenna port 15. That is, from the perspective of one UE, some of DM-RS antenna port 0 through DM-RS antenna port 7 and some of DM-RS antenna port 8 through DM-RS antenna port 15 cannot be indicated together. For example, in the case of rank 4, DM-RS antenna port 0, DM-RS antenna port 1, DM-RS antenna port 10, and DM-RS antenna port 11 cannot be indicated.

[0140] To alleviate this problem and enable more flexible DM-RS antenna port indication, different offsets can be applied to each port or port set. For example, for ranks 4 and above, the first two DM-RS antenna ports are increased by an offset f1, and the other two DM-RS antenna ports are increased by an offset f2. Furthermore, for ranks 4 and below, the indicated DM-RS antenna port is increased by an offset f when indicating DM-RS antenna ports.

[0141] For more flexible application, the offsets can be set so that, among the indicated DM-RS antenna ports, the first and second DM-RS antenna ports are increased by f1, the third and fourth DM-RS antenna ports are increased by f2, and the fifth and sixth DM-RS antenna ports are increased by f3.

[0142] <Proposal 2>

[0143] Proposal 1 of the present disclosure can be utilized in a scheme that increases the length of the Time Domain (TD)-Orthogonal Cover Code (OCC), a scheme that increases the length of the Frequency Domain (FD)-OCC, or a scheme that increases the number of DM-RS antenna ports by the TDM scheme, but is not effective in an FDM scheme (i.e., a scheme that increases the number of DM-RS CDM groups and increases the number of DM-RS antenna ports) because the DM-RS indicator table indicates the number of DM-RS CDM groups without data, and the increased number of DM-RS CDM groups is not reflected in the DM-RS indicator table.

[0144] Here, Proposal 2 of the present disclosure proposes to double the number of DM-RS CDM groups with no data in the DM-RS indicator table and interpret it accordingly, i.e., if the number of DM-RS CDM groups with no data is 1, 2, or 3, it should be interpreted as 2, 4, or 6, respectively.

[0145] Conventional Type 2 DM-RS CDM groups consist of only three groups, DM-RS CDM group 0 to DM-RS CDM group 2, but when new DM-RS patterns are generated by FDM, there can be six groups, DM-RS CDM group 0 to DM-RS CDM group 5.

[0146] A conventional DM-RS indicator table will be taken as an example.

[0147] Table 7 illustrates a conventional DM-RS indicator table for a Type 2 DM-RS where the maximum number of FL (Front-Loaded) DM-RS symbols is two.

[0148] [Table 7]

[0149] For example, in Table 7, Proposal 1 is applied only when the single codeword case is used and the number of FL symbols is 2, and further, when the number of DM-RS CDM groups without data is 1 to 3, the number of DM-RS CDM groups is interpreted as 2, 4, and 6, respectively.

[0150] Specifically, if the number of DM-RS CDM groups is interpreted as 2, DM-RS CDM group 0 and DM-RS CDM group 1 are deemed to be indicated; if the number of DM-RS CDM groups is interpreted as 4, DM-RS CDM group 0 through DM-RS CDM group 3 are deemed to be indicated; and if the number of DM-RS CDM groups is interpreted as 6, DM-RS CDM group 0 through DM-RS CDM group 5 are deemed to be indicated.

[0151] In this case, DM-RS antenna port 0, DM-RS antenna port 1, DM-RS antenna port 6, and DM-RS antenna port 7 are configured in DM-RS CDM group 0, and DM-RS antenna port 12, DM-RS antenna port 13, DM-RS antenna port 18, and DM-RS antenna port 19, which have an offset of 12 added, are configured in DM-RS CDM group 1.

[0152] In addition, DM-RS antenna port 2, DM-RS antenna port 3, DM-RS antenna port 8, and DM-RS antenna port 9 are configured in DM-RS CDM group 2, and DM-RS antenna port 14, DM-RS antenna port 15, DM-RS antenna port 20, and DM-RS antenna port 21, which have an offset of 12 added, are configured in DM-RS CDM group 3.

[0153] Similarly, DM-RS antenna port 4, DM-RS antenna port 5, DM-RS antenna port 10, and DM-RS antenna port 11 are configured in DM-RS CDM group 4, and DM-RS antenna port 16, DM-RS antenna port 17, DM-RS antenna port 22, and DM-RS antenna port 23, which have an offset of 12 added, are configured in DM-RS CDM group 5.

[0154] In addition, for backward compatibility with legacy UEs, the RE union of DM-RS CDM group 0 and DM-RS CDM group 1 must have the same RE position as conventional DM-RS CDM group 0, the RE union of DM-RS CDM group 2 and DM-RS CDM group 3 must have the same RE position as conventional DM-RS CDM group 1, and the RE union of DM-RS CDM group 4 and DM-RS CDM group 5 must have the same RE position as conventional DM-RS CDM group 2.

[0155] Proposal 2 is applied to Type 1 DM-RS as follows:

[0156] If the number of DM-RS CDM groups without data is 1 or 2, it should be interpreted as the number of DM-RS CDM groups without data being 2 or 4, respectively.

[0157] For example, in Table 6, Proposal 1 is applied only when the single codeword case is present and the number of FL symbols is 2, and further, if the number of DM-RS CDM groups without data is 1 or 2, the number of DM-RS CDM groups without data is interpreted as 2 or 4, respectively.

[0158] If the number of DM-RS CDM groups without data is interpreted as 2, then DM-RS CDM group 0 and DM-RS CDM group 1 are deemed to be indicated, and if the number of DM-RS CDM groups without data is interpreted as 4, then DM-RS CDM group 0 through DM-RS CDM group 3 are deemed to be indicated.

[0159] DM-RS antenna port 0, DM-RS antenna port 1, DM-RS antenna port 4, and DM-RS antenna port 5 are configured in DM-RS CDM group 0, and DM-RS antenna port 8, DM-RS antenna port 9, DM-RS antenna port 12, and DM-RS antenna port 13, which are offset by 8, are configured in DM-RS CDM group 1.

[0160] In addition, DM-RS antenna port 2, DM-RS antenna port 3, DM-RS antenna port 6, and DM-RS antenna port 7 are configured in DM-RS CDM group 2, and DM-RS antenna port 10, DM-RS antenna port 11, DM-RS antenna port 14, and DM-RS antenna port 15, which have an offset of 8 added, are configured in DM-RS CDM group 3.

[0161] In addition, for backward compatibility with legacy UEs, the RE union of DM-RS CDM group 0 and DM-RS CDM group 1 must have the same RE position as conventional DM-RS CDM group 0, and the RE union of DM-RS CDM group 2 and DM-RS CDM group 3 must have the same RE position as conventional DM-RS CDM group 1.

[0162] The DM-RS antenna port indication method can finally be applied by combining / joining the above proposals mentioned in this disclosure.

[0163] FIG. 8 is a flowchart illustrating a process for receiving a PDSCH according to the present disclosure.

[0164] Referring to Figure 8, in step A05, the UE receives Downlink Control Information (DCI) for PDSCH from the BS, where the DCI includes demodulation reference signal (DM-RS) port information and information on the number of DM-RS CDM groups without data.

[0165] Next, in step A10, the UE identifies at least one DM-RS port from among the DM-RS ports included in the first DM-RS port group and the DM-RS ports included in the second DM-RS port group using the DM-RS port information included in the DCI. Specifically, the DM-RS ports included in the second DM-RS port group are determined based on the DM-RS ports included in the first DM-RS port group and at least one offset.

[0166] Preferably, the DCI schedules a single codeword via the PDSCH and is limited to the case where the number of FL (Front-Loaded) symbols of the DM-RS is two, and the DM-RS ports included in the second DM-RS port group are determined based on the one offset.

[0167] More preferably, the minimum value of the at least one offset is 0, and the maximum value of the at least one offset is determined based on the type of the DM-RS. Specifically, if the type of the DM-RS is a first type, the maximum value of the at least one offset is 8, and if the type of the DM-RS is a second type, the maximum value of the at least one offset is 12. Furthermore, if the number of DM-RS ports identified by the DM-RS port information is two or more, the DM-RS port information includes information on offsets corresponding to each of the two or more DM-RS ports.

[0168] Finally, in step A15, the UE receives the PDSCH from the BS based on the identified DM-RS port.

[0169] For reference, if the DCI schedules multiple codewords via the PDSCH or the number of FL (Front-Loaded) symbols of the DM-RS is 1, it is preferable to interpret the number of DM-RS CDM groups without data of the DM-RS as twice the number of DM-RS CDM groups without data included in the DCI.

[0170] FIG. 9 illustrates a communication system 1 to which the present invention can be applied.

[0171] Referring to FIG. 9, the communication system 1 includes wireless devices, base stations, and a network. Here, the wireless devices refer to devices that communicate using wireless connection technologies (e.g., 5G NR, LTE), and are also referred to as communication / wireless / 5G devices. The wireless devices include, but are not limited to, a robot 100a, vehicles 100b-1 and 100b-2, an XR (eXtended Reality) device 100c, a handheld device 100d, a home appliance 100e, an IoT (Internet of Things) device 100f, and an AI server / device 400. For example, the vehicles include vehicles equipped with wireless communication capabilities, autonomous vehicles, vehicles capable of vehicle-to-vehicle communication, and the like. Here, the vehicles include unmanned aerial vehicles (UAVs) (e.g., drones). XR devices include Augmented Reality (AR), Virtual Reality (VR), and Mixed Reality (MR) devices, and are embodied in the form of Head-Mounted Devices (HMDs), Head-Up Displays (HUDs) mounted on vehicles, TVs, smartphones, computers, wearable devices, home appliances, digital billboards, vehicles, robots, etc. Mobile devices include smartphones, smart pads, wearable devices (e.g., smart watches, smart glasses), computers (e.g., laptops, etc.), etc. Home appliances include TVs, refrigerators, washing machines, etc. IoT devices include sensors, smart meters, etc. For example, base stations and networks may also be embodied as wireless devices, and a specific wireless device 200a may operate as a base station / network node for other wireless devices.

[0172] The wireless devices 100a to 100f are connected to a network 300 via a base station 200. The wireless devices 100a to 100f are equipped with AI (Artificial Intelligence) technology, and are connected to an AI server 400 via the network 300. The network 300 is configured using a 3G network, a 4G (e.g., LTE) network, or a 5G (e.g., NR) network. The wireless devices 100a to 100f can communicate with each other via the base station 200 / network 300, but can also communicate directly without going through the base station / network (e.g., sidelink communication). For example, vehicles 100b-1 and 100b-2 can communicate directly (e.g., V2V (Vehicle to Vehicle) / V2X (Vehicle to Everything) communication). IoT devices (e.g., sensors) can also communicate directly with other IoT devices (e.g., sensors) or other wireless devices 100a to 100f.

[0173] Wireless communication / connections 150a, 150b, and 150c are performed between the wireless devices 100a to 100f and the base stations 200, and between the base stations 200. Here, the wireless communication / connections are performed using various wireless connection technologies such as uplink / downlink communication 150a and sidelink communication 150b (or D2D communication), and communication between base stations 150c (e.g., relay, Integrated Access Backhaul (IAB)) (e.g., 5G NR). Through the wireless communication / connections 150a, 150b, and 150c, the wireless devices and the base stations, and the base stations, can transmit / receive wireless signals to / from each other. For example, the wireless communication / connections 150a, 150b, and 150c can transmit / receive signals via various physical channels. To this end, various configuration information setting processes for transmitting / receiving wireless signals, various signal processing processes (e.g., channel coding / decoding, modulation / demodulation, resource mapping / demapping, etc.), and / or resource allocation processes are performed according to various proposals of the present invention.

[0174] FIG. 10 illustrates a wireless device to which the present invention can be applied.

[0175] 10, a first wireless device 100 and a second wireless device 200 transmit and receive wireless signals using various wireless access technologies (e.g., LTE, NR), where {first wireless device 100, second wireless device 200} corresponds to {wireless device 100x, base station 200} and / or {wireless device 100x, wireless device 100x} in FIG.

[0176] The first wireless device 100 includes one or more processors 102 and one or more memories 104, and further includes one or more transceivers 106 and / or one or more antennas 108. The processor 102 is configured to control the memory 104 and / or the transceiver 106 to implement the descriptions, functions, procedures, suggestions, methods, and / or flowcharts disclosed herein. For example, the processor 102 processes information in the memory 104 to generate first information / signals and then transmits a wireless signal including the first information / signals via the transceiver 106. The processor 102 also receives a wireless signal including second information / signals via the transceiver 106 and then stores information obtained from signal processing of the second information / signals in the memory 104. The memory 104 is coupled to the processor 102 and stores various information related to the operation of the processor 102. For example, the memory 104 stores software code including instructions for performing some or all of the processes controlled by the processor 102 or for implementing the descriptions, functions, procedures, suggestions, methods, and / or flowcharts disclosed herein. Here, the processor 102 and memory 104 are part of a communication modem / circuit / chip designed to implement a wireless communication technology (e.g., LTE, NR). The transceiver 106 is coupled to the processor 102 and transmits and / or receives wireless signals via one or more antennas 108. The transceiver 106 includes a transmitter and / or a receiver. The transceiver 106 may also be referred to as an RF (radio frequency) unit. In the present invention, a wireless device may also refer to a communication modem / circuit / chip.

[0177] The second wireless device 200 includes one or more processors 202 and one or more memories 204, and further includes one or more transceivers 206 and / or one or more antennas 208. The processor 202 is configured to control the memory 204 and / or the transceiver 206 to implement the descriptions, functions, procedures, suggestions, methods, and / or flowcharts disclosed herein. For example, the processor 202 processes information in the memory 204 to generate third information / signal, and then transmits a wireless signal including the third information / signal via the transceiver 206. The processor 202 also receives a wireless signal including a fourth information / signal via the transceiver 206, and then stores information obtained from signal processing of the fourth information / signal in the memory 204. The memory 204 is coupled to the processor 202 and stores various information related to the operation of the processor 202. For example, the memory 204 stores software code including instructions for performing some or all of the processes controlled by the processor 202 or for implementing the descriptions, functions, procedures, suggestions, methods, and / or flowcharts disclosed herein. Here, the processor 202 and memory 204 are part of a communication modem / circuit / chip designed to implement a wireless communication technology (e.g., LTE, NR). The transceiver 206 is coupled to the processor 202 and transmits and / or receives wireless signals via one or more antennas 208. The transceiver 206 includes a transmitter and / or a receiver. The transceiver 206 may also be referred to as an RF unit. In the present invention, a wireless device may also refer to a communication modem / circuit / chip.

[0178] The hardware elements of the wireless devices 100, 200 are described in more detail below. Without limitation, one or more protocol layers may be implemented by one or more processors 102, 202. For example, one or more processors 102, 202 may implement one or more layers (e.g., functional layers such as PHY, MAC, RLC, PDCP, RRC, and SDAP). The one or more processors 102, 202 may generate one or more Protocol Data Units (PDUs) and / or one or more Service Data Units (SDUs) according to the descriptions, functions, procedures, suggestions, methods, and / or flowcharts disclosed herein. The one or more processors 102, 202 may generate messages, control information, data, or information according to the descriptions, functions, procedures, suggestions, methods, and / or flowcharts disclosed herein. The one or more processors 102, 202 generate signals (e.g., baseband signals) including PDUs, SDUs, messages, control information, data, or information according to the functions, procedures, suggestions, and / or methods disclosed herein and provide them to the one or more transceivers 106, 206. The one or more processors 102, 202 receive signals (e.g., baseband signals) from the one or more transceivers 106, 206 and derive the PDUs, SDUs, messages, control information, data, or information according to the descriptions, functions, procedures, suggestions, methods, and / or flowcharts disclosed herein.

[0179] The one or more processors 102, 202 may also be referred to as a controller, microcontroller, microprocessor, or microcomputer. The one or more processors 102, 202 may be implemented using hardware, firmware, software, or a combination thereof. For example, the one or more processors 102, 202 may include one or more application-specific integrated circuits (ASICs), one or more digital signal processors (DSPs), one or more digital signal processing devices (DSPDs), one or more programmable logic devices (PLDs), or one or more field programmable gate arrays (FPGAs). The descriptions, functions, procedures, suggestions, methods, and / or flowcharts disclosed herein may be implemented using firmware or software, and the firmware or software may be embodied to include modules, procedures, functions, etc. Firmware or software configured to perform the descriptions, functions, procedures, suggestions, methods, and / or flowcharts disclosed herein may be included in the one or more processors 102, 202 or may be stored in one or more memories 104, 204 and executed by the one or more processors 102, 202. The descriptions, functions, procedures, suggestions, methods and / or flow charts disclosed in this specification may be embodied using firmware or software in the form of code, instructions and / or sets of instructions.

[0180] One or more memories 104, 204 may be coupled to one or more processors 102, 202 and may store various types of data, signals, messages, information, programs, code, instructions, and / or commands. The one or more memories 104, 204 may be comprised of ROM, RAM, EPROM, flash memory, hard drives, registers, cache memory, computer-readable storage media, and / or combinations thereof. The one or more memories 104, 204 may be located internal and / or external to the one or more processors 102, 202. Additionally, the one or more memories 104, 204 may be coupled to the one or more processors 102, 202 via various techniques, such as wired or wireless connections.

[0181] One or more transceivers 106, 206 can transmit user data, control information, wireless signals / channels, etc., as referenced in the methods and / or flowcharts herein to one or more other devices. One or more transceivers 106, 206 can receive user data, control information, wireless signals / channels, etc., as referenced in the descriptions, functions, procedures, suggestions, methods and / or flowcharts herein from one or more other devices. For example, one or more transceivers 106, 206 can be coupled to one or more processors 102, 202 and can transmit and receive wireless signals. For example, one or more processors 102, 202 can control one or more transceivers 106, 206 to transmit user data, control information, or wireless signals to one or more other devices. Also, one or more processors 102, 202 can control one or more transceivers 106, 206 to receive user data, control information, or wireless signals from one or more other devices. Furthermore, one or more transceivers 106, 206 are coupled to one or more antennas 108, 208, and are configured to transmit and receive user data, control information, radio signals / channels, etc., as referred to in the descriptions, functions, procedures, suggestions, methods, and / or flowcharts disclosed herein via the one or more antennas 108, 208. In this specification, one or more antennas may refer to multiple physical antennas or multiple logical antennas (e.g., antenna ports). The one or more transceivers 106, 206 convert the received user data, control information, radio signals / channels, etc., from RF band signals to baseband signals for processing by one or more processors 102, 202. The one or more transceivers 106, 206 convert the user data, control information, radio signals / channels, etc., processed by one or more processors 102, 202, from baseband signals to RF band signals. For this purpose, the one or more transceivers 106, 206 include (analog) oscillators and / or filters.

[0182] 11 shows another example of a wireless device to which the present invention is applied. The wireless device may be implemented in various forms depending on the use case / service (see FIG. 9).

[0183] 11, wireless devices 100 and 200 correspond to the wireless devices 100 and 200 of FIG. 10 and are composed of various elements, components, units / sections, and / or modules. For example, the wireless devices 100 and 200 include a communication unit 110, a control unit 120, a memory unit 130, and an additional element 140. The communication unit includes a communication circuit 112 and a transceiver 114. For example, the communication circuit 112 includes one or more processors 102 and 202 and / or one or more memories 104 and 204 in FIG. 10. For example, the transceiver 114 includes one or more transceivers 106 and 206 and / or one or more antennas 108 and 208 in FIG. 10. The control unit 120 is electrically coupled to the communication unit 110, the memory unit 130, and the additional element 140 and controls the overall operation of the wireless device. For example, the control unit 120 controls the electrical / mechanical operations of the wireless device based on the programs / codes / instructions / information stored in the memory unit 130. The control unit 120 also transmits the information stored in the memory unit 130 to an external device (e.g., another communication device) via the communication unit 110 via a wireless / wired interface, or stores information received from an external device (e.g., another communication device) via the communication unit 110 via a wireless / wired interface in the memory unit 130.

[0184] The additional element 140 may be configured in various ways depending on the type of wireless device. For example, the additional element 140 may include any one of a power unit / battery, an input / output unit (I / O unit), a driving unit, and a computer unit. Wireless devices may be embodied in the form of, but not limited to, a robot (FIG. 9, 100a), a vehicle (FIG. 9, 100b-1, 100b-2), an XR device (FIG. 9, 100c), a mobile device (FIG. 9, 100d), a home appliance (FIG. 9, 100e), an IoT device (FIG. 9, 100f), a digital broadcasting terminal, a hologram device, a public safety device, an MTC device, a medical device, a FinTech device (or financial device), a security device, a climate / environment device, an AI server / device (FIG. 9, 400), a base station (FIG. 9, 200), a network node, etc. Wireless devices may be mobile or fixed depending on the use case / service.

[0185] In FIG. 11, the various elements, components, units / sections and / or modules within the wireless devices 100, 200 are all connected to each other by wired interfaces or at least some are connected wirelessly by a communication section 110. For example, in the wireless devices 100 and 200, the control unit 120 and the communication unit 110 are connected by wire, and the control unit 120 and the first unit (e.g., 130, 140) are connected wirelessly via the communication unit 110. Furthermore, each element, component, unit / part and / or module in the wireless devices 100 and 200 further includes one or more elements. For example, the control unit 120 is configured with a set of one or more processors. For example, the control unit 120 is configured with a set of a communication control processor, an application processor, an ECU (Electronic Control Unit), a graphics processor, a memory control processor, etc. As another example, the memory unit 130 is configured with a RAM (Random Access Memory), a DRAM (Dynamic RAM), a ROM (Read Only Memory), a flash memory, a volatile memory, a non-volatile memory and / or a combination thereof.

[0186] 12 is a diagram illustrating an example of a vehicle or an autonomous vehicle to which the present invention is applied. The vehicle or the autonomous vehicle may be embodied as a mobile robot, a car, a train, an aerial vehicle (AV), a ship, etc.

[0187] One or more memories 104, 204 may be coupled to one or more processors 102, 202 and may store various types of data, signals, messages, information, programs, code, instructions, and / or commands. The one or more memories 104, 204 may be comprised of ROM, RAM, EPROM, flash memory, hard drives, registers, cache memory, computer-readable storage media, and / or combinations thereof. The one or more memories 104, 204 may be located internal and / or external to the one or more processors 102, 202. Additionally, the one or more memories 104, 204 may be coupled to the one or more processors 102, 202 via various techniques, such as wired or wireless connections.

[0188] One or more transceivers 106, 206 can transmit user data, control information, wireless signals / channels, etc., as referenced in the methods and / or flowcharts herein to one or more other devices. One or more transceivers 106, 206 can receive user data, control information, wireless signals / channels, etc., as referenced in the descriptions, functions, procedures, suggestions, methods and / or flowcharts herein from one or more other devices. For example, one or more transceivers 106, 206 can be coupled to one or more processors 102, 202 and can transmit and receive wireless signals. For example, one or more processors 102, 202 can control one or more transceivers 106, 206 to transmit user data, control information, or wireless signals to one or more other devices. Also, one or more processors 102, 202 can control one or more transceivers 106, 206 to receive user data, control information, or wireless signals from one or more other devices. Furthermore, one or more transceivers 106, 206 are coupled to one or more antennas 108, 208, and are configured to transmit and receive user data, control information, radio signals / channels, etc., as referred to in the descriptions, functions, procedures, suggestions, methods, and / or flowcharts disclosed herein via the one or more antennas 108, 208. In this specification, one or more antennas may refer to multiple physical antennas or multiple logical antennas (e.g., antenna ports). The one or more transceivers 106, 206 convert the received user data, control information, radio signals / channels, etc., from RF band signals to baseband signals for processing by one or more processors 102, 202. The one or more transceivers 106, 206 convert the user data, control information, radio signals / channels, etc., processed by one or more processors 102, 202, from baseband signals to RF band signals. For this purpose, the one or more transceivers 106, 206 include (analog) oscillators and / or filters.

[0189] 11 shows another example of a wireless device to which the present invention is applied. The wireless device may be implemented in various forms depending on the use case / service (see FIG. 9).

[0190] 11, wireless devices 100 and 200 correspond to the wireless devices 100 and 200 of FIG. 10 and are composed of various elements, components, units / sections, and / or modules. For example, the wireless devices 100 and 200 include a communication unit 110, a control unit 120, a memory unit 130, and an additional element 140. The communication unit includes a communication circuit 112 and a transceiver 114. For example, the communication circuit 112 includes one or more processors 102 and 202 and / or one or more memories 104 and 204 in FIG. 10. For example, the transceiver 114 includes one or more transceivers 106 and 206 and / or one or more antennas 108 and 208 in FIG. 10. The control unit 120 is electrically coupled to the communication unit 110, the memory unit 130, and the additional element 140 and controls the overall operation of the wireless device. For example, the control unit 120 controls the electrical / mechanical operations of the wireless device based on the programs / codes / instructions / information stored in the memory unit 130. The control unit 120 also transmits the information stored in the memory unit 130 to an external device (e.g., another communication device) via the communication unit 110 via a wireless / wired interface, or stores information received from an external device (e.g., another communication device) via the communication unit 110 via a wireless / wired interface in the memory unit 130.

[0191] The additional element 140 may be configured in various ways depending on the type of wireless device. For example, the additional element 140 may include any one of a power unit / battery, an input / output unit (I / O unit), a driving unit, and a computer unit. Wireless devices may be embodied in the form of, but not limited to, a robot (FIG. 9, 100a), a vehicle (FIG. 9, 100b-1, 100b-2), an XR device (FIG. 9, 100c), a mobile device (FIG. 9, 100d), a home appliance (FIG. 9, 100e), an IoT device (FIG. 9, 100f), a digital broadcasting terminal, a hologram device, a public safety device, an MTC device, a medical device, a FinTech device (or financial device), a security device, a climate / environment device, an AI server / device (FIG. 9, 400), a base station (FIG. 9, 200), a network node, etc. Wireless devices may be mobile or fixed depending on the use case / service.

[0192] In FIG. 11, the various elements, components, units / sections and / or modules within the wireless devices 100, 200 are all connected to each other by wired interfaces or at least some are connected wirelessly by a communication section 110. For example, in the wireless devices 100 and 200, the control unit 120 and the communication unit 110 are connected by wire, and the control unit 120 and the first unit (e.g., 130, 140) are connected wirelessly via the communication unit 110. Furthermore, each element, component, unit / part and / or module in the wireless devices 100 and 200 further includes one or more elements. For example, the control unit 120 is configured with a set of one or more processors. For example, the control unit 120 is configured with a set of a communication control processor, an application processor, an ECU (Electronic Control Unit), a graphics processor, a memory control processor, etc. As another example, the memory unit 130 is configured with a RAM (Random Access Memory), a DRAM (Dynamic RAM), a ROM (Read Only Memory), a flash memory, a volatile memory, a non-volatile memory and / or a combination thereof.

[0193] 12 is a diagram illustrating an example of a vehicle or an autonomous vehicle to which the present invention is applied. The vehicle or the autonomous vehicle may be embodied as a mobile robot, a car, a train, an aerial vehicle (AV), a ship, etc.

[0194] 12, a vehicle or autonomous vehicle 100 includes an antenna unit 108, a communication unit 110, a control unit 120, a drive unit 140a, a power supply unit 140b, a sensor unit 140c, and an autonomous driving unit 140d. The antenna unit 108 is configured as part of the communication unit 110. Blocks 110 / 130 / 140a to 140d correspond to blocks 110 / 130 / 140 in FIG. 11, respectively.

[0195] The communication unit 110 transmits and receives signals (e.g., data, control signals, etc.) to and from external devices such as other vehicles, base stations (e.g., base stations, roadside units, etc.), and servers. The control unit 120 controls elements of the vehicle or autonomous vehicle 100 to perform various operations. The control unit 120 includes an ECU (Electronic Control Unit). The driving unit 140a causes the vehicle or autonomous vehicle 100 to move on the ground. The driving unit 140a includes an engine, a motor, a powertrain, wheels, brakes, a steering device, etc. The power supply unit 140b supplies power to the vehicle or autonomous vehicle 100 and includes wired / wireless charging circuits, a battery, etc. The sensor unit 140c can obtain vehicle status, surrounding environment information, user information, etc. The sensor unit 140c includes an IMU (inertial measurement unit) sensor, a collision sensor, a wheel sensor, a speed sensor, an inclination sensor, a weight detection sensor, a heading sensor, a position module, a vehicle forward / reverse sensor, a battery sensor, a fuel sensor, a tire sensor, a steering sensor, a temperature sensor, a humidity sensor, an ultrasonic sensor, an illuminance sensor, a pedal position sensor, etc. The autonomous driving unit 140d implements technology for maintaining a lane while driving, technology for automatically adjusting speed such as adaptive cruise control, technology for automatically driving along a predetermined route, technology for automatically setting a route and driving when a destination is set, etc.

[0196] For example, the communication unit 110 receives map data, traffic information data, etc. from an external server. The autonomous driving unit 140d generates an autonomous driving route and a driving plan based on the obtained data. The control unit 120 controls the driving unit 140a (e.g., adjusting speed / direction) so that the vehicle or autonomous vehicle 100 moves along the autonomous driving route according to the driving plan. The communication unit 110 aperiodically obtains the latest traffic information data from an external server during autonomous driving and also obtains surrounding traffic information data from surrounding vehicles. In addition, the sensor unit 140c obtains vehicle status and surrounding environment information during autonomous driving. The autonomous driving unit 140d updates the autonomous driving route and driving plan based on the newly obtained data / information. The communication unit 110 transmits information regarding the vehicle position, autonomous driving route, driving plan, etc. to an external server. The external server can predict traffic information data using AI technology based on information collected from the vehicle or autonomous vehicle and provide the predicted traffic information data to the vehicle or autonomous vehicle.

[0197] The above-described embodiments are combinations of the elements and features of the present invention in a predetermined form. Each element or feature should be considered optional unless otherwise explicitly stated. Each element or feature may be implemented without being combined with other elements or features. It is also possible to combine some elements and / or features to form an embodiment of the present invention. The order of operations described in the embodiments of the present invention may be changed. Some elements or features of any embodiment may be included in other embodiments, or may be replaced with corresponding elements or features of other embodiments. It is obvious that claims that are not explicitly cited in the claims may be combined to form an embodiment, or may be included as new claims by amendment after filing.

[0198] It is obvious to those skilled in the art that the present invention can be embodied in other specific forms without departing from the characteristics of the present invention. Therefore, the above detailed description should not be construed as limiting in all respects, but should be considered as illustrative. The scope of the present invention should be determined by reasonable interpretation of the appended claims, and all modifications within the equivalent scope of the present invention are included in the scope of the present invention. [Industrial Applicability]

[0199] The present invention can be used in a terminal, a base station or other equipment of a wireless mobile communication system.

Claims

1. A method performed by a UE (User Equipment) in a wireless communication system, receiving Downlink Control Information (DCI) for a Physical Downlink Shared Channel (PDSCH) from a Base Station (BS); receiving the PDSCH from the BS based on port information of a demodulation reference signal (DM-RS) included in the DCI; The port information of the DM-RS is Identifying at least one DM-RS port from among a DM-RS port included in a first DM-RS port group and a DM-RS port included in a second DM-RS port group; The DM-RS ports included in the second DM-RS port group are The DM-RS port is determined based on the DM-RS port included in the first DM-RS port group and at least one offset. method.

2. the minimum value of the at least one offset is 0; If the type of the DM-RS is a first type, the maximum value of the at least one offset is 8; When the type of the DM-RS is a second type, the maximum value of the at least one offset is 12. The method of claim 1.

3. When the number of DM-RS ports identified by the port information of the DM-RS is two or more, the port information of the DM-RS is The information includes information regarding offsets corresponding to each of the two or more DM-RS ports. The method of claim 1.

4. the DCI schedules a single codeword over the PDSCH; The number of FL (Front-Loaded) symbols of the DM-RS is 2, The method of claim 1.

5. The DCI includes information regarding the number of DM-RS CDM groups without data, When the DCI schedules multiple codewords over the PDSCH or the number of FL (Front-Loaded) symbols of the DM-RS is 1, the number of DM-RS CDM groups without data of the DM-RS is twice the number of DM-RS CDM groups without data included in the DCI. The method of claim 1.

6. In a wireless communication system, a UE (User Equipment) at least one transceiver; at least one processor; at least one computer memory operably connected to said at least one processor and storing instructions that, when executed, cause said at least one processor to perform operations, said operations including: receiving Downlink Control Information (DCI) for a Physical Downlink Shared Channel (PDSCH) from a Base Station (BS); receiving the PDSCH from the BS based on port information of a demodulation reference signal (DM-RS) included in the DCI; The port information of the DM-RS is Identifying at least one DM-RS port from among a DM-RS port included in a first DM-RS port group and a DM-RS port included in a second DM-RS port group; The DM-RS ports included in the second DM-RS port group are The DM-RS port is determined based on the DM-RS port included in the first DM-RS port group and at least one offset. UE.

7. the minimum value of the at least one offset is 0; If the type of the DM-RS is a first type, the maximum value of the at least one offset is 8; When the type of the DM-RS is a second type, the maximum value of the at least one offset is 12. The UE of claim 6.

8. When the number of DM-RS ports identified by the port information of the DM-RS is two or more, the port information of the DM-RS is The information includes information regarding offsets corresponding to each of the two or more DM-RS ports. The UE of claim 6.

9. the DCI schedules a single codeword over the PDSCH; The number of FL (Front-Loaded) symbols of the DM-RS is 2, The UE of claim 6.

10. The DCI includes information regarding the number of DM-RS CDM groups without data, When the DCI schedules multiple codewords over the PDSCH or the number of FL (Front-Loaded) symbols of the DM-RS is 1, the number of DM-RS CDM groups without data of the DM-RS is twice the number of DM-RS CDM groups without data included in the DCI. The UE of claim 6.

11. In a wireless communication system, a processing device comprising: at least one processor; and at least one computer memory operably connected to the at least one processor and storing instructions that, when executed, cause the at least one processor to perform operations for a User Equipment (UE), the operations including: receiving Downlink Control Information (DCI) for a Physical Downlink Shared Channel (PDSCH) from a Base Station (BS); receiving the PDSCH from the BS based on port information of a demodulation reference signal (DM-RS) included in the DCI; The port information of the DM-RS is Identifying at least one DM-RS port from among a DM-RS port included in a first DM-RS port group and a DM-RS port included in a second DM-RS port group; The DM-RS ports included in the second DM-RS port group are The DM-RS port is determined based on the DM-RS port included in the first DM-RS port group and at least one offset. Processing equipment.

12. 1. A computer-readable storage medium, comprising: The storage medium stores at least one program code including instructions that, when executed, cause at least one processor to perform an operation for a UE (User Equipment), the operation including: receiving Downlink Control Information (DCI) for a Physical Downlink Shared Channel (PDSCH) from a Base Station (BS); receiving the PDSCH from the BS based on port information of a demodulation reference signal (DM-RS) included in the DCI; The port information of the DM-RS is Identifying at least one DM-RS port from among a DM-RS port included in a first DM-RS port group and a DM-RS port included in a second DM-RS port group; The DM-RS ports included in the second DM-RS port group are The DM-RS port is determined based on the DM-RS port included in the first DM-RS port group and at least one offset. Storage medium.

13. A method performed by a BS (Base Station) in a wireless communication system, transmitting Downlink Control Information (DCI) for a Physical Downlink Shared Channel (PDSCH) to a User Equipment (UE); transmitting the PDSCH to the UE based on port information of a demodulation reference signal (DM-RS) included in the DCI; The port information of the DM-RS is indicating at least one DM-RS port among a DM-RS port included in a first DM-RS port group and a DM-RS port included in a second DM-RS port group; The DM-RS ports included in the second DM-RS port group are The DM-RS port is determined based on the DM-RS port included in the first DM-RS port group and at least one offset. method.

14. the minimum value of the at least one offset is 0; If the type of the DM-RS is a first type, the maximum value of the at least one offset is 8; When the type of the DM-RS is a second type, the maximum value of the at least one offset is 12. The method of claim 13.

15. When the number of DM-RS ports identified by the port information of the DM-RS is two or more, the port information of the DM-RS is The information includes information regarding offsets corresponding to each of the two or more DM-RS ports. The method of claim 13.

16. the DCI schedules a single codeword over the PDSCH; The number of FL (Front-Loaded) symbols of the DM-RS is 2, The method of claim 13.

17. The DCI includes information regarding the number of DM-RS CDM groups without data, When the DCI schedules multiple codewords over the PDSCH or the number of FL (Front-Loaded) symbols of the DM-RS is 1, the number of DM-RS CDM groups without data of the DM-RS is twice the number of DM-RS CDM groups without data included in the DCI. The method of claim 13.

18. In a wireless communication system, a BS (Base Station) at least one transceiver; at least one processor; at least one computer memory operably connected to said at least one processor and storing instructions that, when executed, cause said at least one processor to perform operations, said operations including: transmitting Downlink Control Information (DCI) for a Physical Downlink Shared Channel (PDSCH) to a User Equipment (UE); transmitting the PDSCH to the UE based on port information of a demodulation reference signal (DM-RS) included in the DCI; The port information of the DM-RS is indicating at least one DM-RS port among a DM-RS port included in a first DM-RS port group and a DM-RS port included in a second DM-RS port group; The DM-RS ports included in the second DM-RS port group are The DM-RS port is determined based on the DM-RS port included in the first DM-RS port group and at least one offset. B.S.

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