A method and apparatus for transmitting channel state information for multiple time instances in a wireless communication system.

Abstract

Providing methods for UE (Unified User) actions in wireless communication systems. [Solution] The method includes the steps of: receiving a control signal from a BS for CSI reporting; receiving at least one CMR from the BS based on the control signal; calculating at least one PMI for at least one time instance in a TD compressed codebook based on the at least one CMR; and transmitting the CSI to the BS, which includes information on a plurality of NZCs related to the at least one PMI, based on the uplink grant resources included in the control signal, wherein the plurality of NZCs have priority values ​​determined by considering, in order, the index of the TD basis vector, the index of the FD basis vector, the index of the SD basis vector, and the layer index.

Description

[Technical Field]

[0001] The present invention relates to a wireless communication system. More specifically, to a method and apparatus for transmitting channel state information for multiple time instances in a wireless communication system. [Background technology]

[0002] Wireless communication systems are 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 (bandwidth, transmission power, etc.). Examples of multiple access systems include CDMA (code division multiple access) systems, FDMA (frequency division multiple access) systems, TDMA (time division multiple access) systems, OFDMA (orthogonal frequency division multiple access) systems, and SC-FDMA (single carrier frequency division multiple access) systems. [Overview of the project] [Problems that the invention aims to solve]

[0003] Based on the arguments presented above, the following proposes a method and apparatus for transmitting channel state information for multiple time instances in a wireless communication system.

[0004] The technical problems that this invention aims to solve are not limited to those described above, and other technical problems not mentioned will be clearly understandable to a person with ordinary skill in the art to which this invention belongs from the following description. [Means for solving the problem]

[0005] As one aspect of the present invention, a method is provided for a User Equipment (UE) in a wireless communication system. The method includes the steps of: receiving a control signal from a Base Station (BS) for reporting Channel Status Information (CSI); receiving at least one channel measurement resource (CMR) from the BS based on the control signal; calculating at least one Precoding Matrix Index (PMI) for at least one time instance in a Time Domain Compressed (TD) codebook based on the at least one CMR; and transmitting the CSI to the BS, which includes information on a plurality of non-zero coefficients (NZCs) related to the at least one PMI, based on the uplink grant resource included in the control signal, wherein the plurality of NZCs have priority values ​​determined by considering, in order, the index of the Time Domain basis vector (TD), the index of the Frequency Domain basis vector (FD), the index of the Spatial Domain basis vector (SD), and the layer index.

[0006] In another aspect of the present invention, a User Equipment (UE) is provided in a wireless communication system. The User Equipment includes at least one transceiver, 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 an operation. The operation includes the steps of: receiving a control signal from a Base Station (BS) for reporting Channel Status Information (CSI); receiving at least one channel measurement resource (CMR) from the BS based on the control signal; calculating at least one Precoding Matrix Index (PMI) for at least one time instance in a Time Domain Compressed (TD) codebook based on the at least one CMR; and transmitting the CSI to the BS, which includes information on a plurality of non-zero coefficients (NZCs) related to the at least one PMI, based on the uplink grant resource included in the control signal, wherein the plurality of NZCs have priority values ​​determined by considering, in order, the index of the Time Domain basis vector (TD), the index of the Frequency Domain basis vector (FD), the index of the Spatial Domain basis vector (SD), and the layer index.

[0007] In yet another aspect of the present invention, a processing device is provided in a wireless communication system. The processing device includes 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 UE (User Equipment). The operation includes the steps of: receiving a control signal from a Base Station (BS) for reporting Channel Status Information (CSI); receiving at least one channel measurement resource (CMR) from the BS based on the control signal; calculating at least one Precoding Matrix Index (PMI) for at least one time instance in a Time Domain Compressed (TD) codebook based on the at least one CMR; and transmitting the CSI to the BS, which includes information on a plurality of non-zero coefficients (NZCs) related to the at least one PMI, based on the uplink grant resource included in the control signal, wherein the plurality of NZCs have priority values ​​determined by considering, in order, the index of the Time Domain basis vector (TD), the index of the Frequency Domain basis vector (FD), the index of the Spatial Domain basis vector (SD), and the layer index.

[0008] In yet another aspect of the present invention, a computer-readable storage medium is provided. The computer-readable storage medium stores at least one computer program which, when executed by at least one processor, causes the at least one processor to perform an action for a UE (User Equipment). The operation includes the steps of: receiving a control signal from a Base Station (BS) for reporting Channel Status Information (CSI); receiving at least one channel measurement resource (CMR) from the BS based on the control signal; calculating at least one Precoding Matrix Index (PMI) for at least one time instance in a Time Domain Compressed (TD) codebook based on the at least one CMR; and transmitting the CSI to the BS, which includes information on a plurality of non-zero coefficients (NZCs) related to the at least one PMI, based on the uplink grant resource included in the control signal, wherein the plurality of NZCs have priority values ​​determined by considering, in order, the index of the Time Domain basis vector (TD), the index of the Frequency Domain basis vector (FD), the index of the Spatial Domain basis vector (SD), and the layer index.

[0009] In each aspect of the present invention, the plurality of NZCs are characterized in that the larger the index of the TD basis vector, the higher the priority value; when the indices of the TD basis vectors are the same, the larger the index of the FD basis vector, when the indices of the TD basis vectors and the FD basis vectors are the same, the larger the index of the SD basis vector, and when the indices of the TD basis vectors, the FD basis vectors and the SD basis vectors are the same, the larger the layer index, the higher the priority value.

[0010] In each aspect of the present invention, the priority order of an NZC having the layer index l, the SD basis vector index i, the FD basis vector index f, and the TD basis vector index t is determined by the following formula.

[0011] [Mathematical formula]

number

[0012] (where υ is a value related to the number of layers, 2L is a value related to the number of SD basis vectors, N3 is a value related to the number of FD basis vectors, and π'(t) is a function that transforms the indices of the TD basis vectors.)

[0013] In each aspect of the present invention, if the uplink grant resource is smaller than the payload of the CSI, the UE drops at least one of the plurality of NZCs in order of the priority value assigned to the plurality of NZCs.

[0014] In each aspect of the present invention, the maximum number of NZCs per layer is determined based on the product of the number of TD basis vectors, the number of FD basis vectors, the number of SD basis vectors, and a constant greater than 0 and less than or equal to 1.

[0015] The above-described problem-solving method is only a part of the embodiments of the present invention, and various embodiments reflecting the technical features of the present invention can be derived and understood by those having ordinary knowledge in the art based on the detailed description of the present invention described below.

Effects of the Invention

[0016] According to the present invention, in a wireless communication system, wireless signals can be efficiently transmitted and received.

[0017] The effects obtained by the present invention are not limited to the effects mentioned above, and other effects not mentioned will be clearly understandable to those having ordinary knowledge in the technical field to which the present invention pertains from the following description.

Brief Description of the Drawings

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

[0019] [Figure 1] It 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] It is a diagram illustrating the structure of a radio frame. [Figure 3] It is a diagram illustrating the resource grid of a slot. [Figure 4] It is a diagram showing an example in which a physical channel is mapped within a slot. [Figure 5] It is a diagram illustrating the PDSCH and ACK / NACK transmission processes. [Figure 6] It is a diagram illustrating the PUSCH transmission process. [Figure 7] It is a diagram showing an example of a CSI-related procedure. [Figure 8]This is a diagram to explain the concepts of AI / ML / Deep Learning. [Figure 9] This diagram illustrates various AI / ML models using deep learning. [Figure 10] This diagram illustrates various AI / ML models using deep learning. [Figure 11] This diagram illustrates various AI / ML models using deep learning. [Figure 12] This diagram illustrates various AI / ML models using deep learning. [Figure 13] This is a diagram illustrating the 3GPP RAN Intelligence framework. [Figure 14] This figure shows an example of reporting PMI for multiple time instances. [Figure 15] This figure shows an example of reporting PMI for multiple time instances. [Figure 16] This disclosure provides a flowchart showing how to report CSI for multiple-time instances. [Figure 17] This figure illustrates a communication system 1 and wireless equipment applicable to the present invention. [Figure 18] This figure illustrates a communication system 1 and wireless equipment applicable to the present invention. [Figure 19] This figure illustrates a communication system 1 and wireless equipment applicable to the present invention. [Figure 20] This figure illustrates a communication system 1 and wireless equipment applicable to the present invention. [Modes for carrying out the invention]

[0020] The following technologies can be used in various wireless connectivity systems such as CDMA (code division multiple access), FDMA (frequency division multiple access), TDMA (time division multiple access), OFDMA (orthogonal frequency division multiple access), and SC-FDMA (single carrier frequency division multiple access). CDMA can be implemented using radio technologies such as UTRA (Universal Terrestrial Radio Access) and CDMA2000. TDMA can be implemented using radio technologies such as GSM (Global System for Mobile communications) / GPRS (General Packet Radio Service) / EDGE (Enhanced Data Rates for GSM Evolution). OFDMA can be implemented using radio technologies such as IEEE 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802-20, and E-UTRA (Evolved UTRA). UTRA is part of UMTS (Universal Mobile Telecommunications System). 3GPP (3rd Generation Partnership Project) LTE (long term evolution) is part of E-UMTS (Evolved UMTS) which 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 demand greater communication capacity, the need for improved mobile broadband communication compared to existing RAT (Radio Access Technology) is emerging. Furthermore, massive machine type communications (MTC), which connects multiple devices and things to provide various services anytime, anywhere, are one of the important issues to consider in next-generation communications. In addition, 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 eMBB (enhanced Mobile Broadband Communication), massive MTC, URLLC (Ultra-Reliable and Low Latency Communication), etc., is being discussed, and in this invention, for convenience, the relevant technology is referred to as NR (New radio or New RAT).

[0022] To clarify the explanation, 3GPP NR will be used as the primary reference, but the technical concept of this invention is not limited to this.

[0023] In this specification, the expression "setting" may be replaced with the expression "configure / configuration," and the two may be used interchangeably. Also, 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." Furthermore, the operation of the terminal / base station or the SW / HW configuration can be inferred / understood based on the satisfaction of the relevant conditions. In addition, 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 / 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 can be understood as signal monitoring / reception / decoding / determination on the receiving side. Furthermore, the expression that a terminal performs (or does not perform) a specific operation can also be interpreted as the base station operating on the expectation / assumption (or expectation / assumption that the terminal will not perform) a specific operation. The expression that a base station performs (or does not perform) a specific operation can also be interpreted as the terminal operating while expecting / assuming (or expecting / assuming that) the base station will perform that specific operation. Furthermore, in the following description, the sections, examples, illustrations, options, methods, schemes, etc., and the index are for the convenience of explanation and should not be interpreted as each necessarily constituting an independent invention or each necessarily being implemented individually. Also, in describing each section, example, illustration, option, method, scheme, etc., unless there is an explicit conflict / contradictory statement, it should be inferred / interpreted that at least some of these may be combined and implemented together, or at least some may be omitted and implemented.

[0024] In wireless communication systems, terminals receive information from base stations via the downlink (DL) and transmit information from base stations via the uplink (UL). The information transmitted and received between base stations and terminals includes data and various control information, and various physical channels exist depending on the type and purpose of the information being transmitted and received.

[0025] Figure 1 illustrates the physical channels used in 3GPP systems and typical signal transmission methods using them.

[0026] A terminal that is powered on from an OFF state or that newly enters a cell performs initial cell search operations, such as establishing synchronization with the base station (S101). For this purpose, the terminal receives an SSB (Synchronization Signal Block) from the base station. The SSB includes a PSS (Primary Synchronization Signal), an SSS (Secondary Synchronization Signal), and a PBCH (Physical Broadcast Channel). Based on the PSS / SSS, the terminal establishes synchronization with the base station and obtains information such as the cell identity. The terminal also obtains broadcast information within the cell based on the PBCH. In addition, during the initial cell search stage, the terminal can receive a Downlink Reference Signal (DL RS) to check the status of the downlink channel.

[0027] Once the initial cell discovery is complete, the terminal receives the Physical Downlink Control Channel (PDCCH) and the Physical Downlink Shared Channel (PDSCH) corresponding to the Physical Downlink Control Channel to obtain more specific system information (S102).

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

[0029] A terminal that has performed these procedures then receives the physical downlink control channel / physical downlink shared channel (S107) and transmits the physical uplink shared channel (PUSCH) / physical uplink control channel (PUCCH) (S108), as part of the general uplink / downlink signal transmission procedure. The control information that the terminal transmits to the base station is called 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 if control information and traffic data need to be transmitted simultaneously. Furthermore, terminals can transmit UCI aperiodically via PUSCH at the request / instruction of the network.

[0030] FIG. 2 is a diagram illustrating the structure of a radio frame. In NR, uplink and downlink transmissions are composed of frames. One radio frame has a length of 10 ms and is divided into two 5 - ms half - frames (HF). One half - frame is divided into five 1 - ms sub - frames (SF). One sub - frame is divided into one or more slots, and the number of slots in a sub - frame depends on the sub - carrier spacing (SCS). Each slot contains 12 or 14 OFDM (Orthogonal Frequency Division Multiplexing) symbols by means of a cyclic prefix (CP). When normal CP is used, each slot contains 14 OFDM symbols. When extended CP is used, each slot contains 12 OFDM symbols.

[0031] Table 1 shows the number of OFDM symbols per slot (N slot symb ), the number of slots per frame (N frame,u slot ), and the number of slots per sub - frame (N subframe,u slot ) when normal CP is used.

[0032]

Table 1

[0033] Table 2 shows the number of OFDM symbols per slot (N slot symb ), the number of slots per frame (N frame,u slot ), and the number of slots per sub - frame (N subframe,u slot ) when extended CP is used.

[0034]

Table 2

[0035] The frame structure shown is merely an example; the number of subframes, slots, and symbols within a frame can be varied in many ways.

[0036] In an NR system, OFDM pneumatics (numerology, e.g., SCS) can be configured to differ between multiple cells merged into a single terminal. This allows the (absolute time) intervals of time resources (e.g., SF, slots, or TTI) (collectively referred to as TU (Time Unit) for convenience), which consist of the same number of symbols, to differ between the merged cells. Here, symbols include OFDM symbols (or CP-OFDM symbols) and SC-FDMA symbols (or Discrete Fourier Transform-spread-OFDM, DFT-s-OFDM symbols).

[0037] Figure 3 illustrates a resource grid for a slot. A single slot contains multiple symbols in the time domain. For example, in the case of a general CP, a single slot contains 14 symbols, while in the case of an extended CP, a single slot contains 12 symbols. A carrier wave contains multiple subcarriers in the frequency domain. An RB (Resource Block) is defined by multiple (e.g., 12) consecutive subcarriers in the frequency domain. A BWP (Bandwidth Part) is defined by multiple consecutive PRBs (Physical RBs) in the frequency domain and can correspond to one numerology (e.g., SCS, CP length). A carrier wave contains up to N (e.g., 5) BWPs. Data communication is performed on activated BWPs, and only one BWP is activated per terminal. In the resource grid, each element is called a Resource Element (RE), and one modulation symbol can be mapped to it.

[0038] Figure 4 shows an example of how physical channels are mapped within a slot. In the DL control domain, PDCCH is transmitted, and in the DL data domain, PDSCH is transmitted. In the UL control domain, PUCCH is transmitted, and in the UL data domain, PUSCH is transmitted. GP provides a time gap during the transition between the base station and the terminal from transmit mode to receive mode or from receive mode to transmit mode. Some symbols at the point of transition from DL to UL within a subframe can be set as GP.

[0039] The following provides a more detailed explanation of each physical channel.

[0040] The PDCCH carries DCI (Downlink Control Information). For example, the PCCCH (i.e., DCI) carries the transmission format and resource allocation for the DL-SCH (downlink shared channel), resource allocation information for the UL-SCH (uplink shared channel), paging information for the PCH (Paging Channel), system information on the DL-SCH, resource allocation information for higher-level control messages such as arbitrary connection responses transmitted on the PDSCH, transmission power control commands, and activation / deactivation of CS (Configured scheduling). The DCI includes a CRC (cyclic redundancy check), 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 P-RNTI (Paging-RNTI). If the PDCCH relates to system information (e.g., System Information Block, SIB), the CRC is masked with SI-RNTI (System Information RNTI). If the PDCCH relates to an arbitrary connection response, the CRC is masked with RA-RNTI (Random Access-RNTI).

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

[0042] For PDCCH reception / detection, the terminal monitors PDCCH candidates. PDCCH candidates indicate CCEs that the terminal should monitor for PDCCH detection. Each PDCCH candidate is defined by AL with 1, 2, 4, 8, or 16 CCEs. Monitoring includes (blind) decoding of PDCCH candidates. The set of PDCCH candidates monitored by the terminal is defined as the PDCCH Search Space (SS). Search spaces include Common Search Spaces (CSS) or UE-specific search spaces (USS). The terminal can obtain a DCI by monitoring PDCCH candidates in one or more search spaces configured by MIB or higher-level signaling. Each CORESET is associated with one or more search spaces, and each search space is associated with one CORESET. Search spaces are defined based on the following parameters:

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

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

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

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

[0047] * A PDCCH (monitoring) opportunity is defined as an opportunity to monitor a PDCCH candidate (e.g., a time / frequency resource). 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 the DCI format transmitted via PDCCH.

[0051] [Table 4]

[0052] DCI format 0_0 is used to schedule TB-based (or TB-level) PUSCH, and DCI format 0_1 ​​is used to schedule TB-based (or TB-level) PUSCH or CBG (Code Block Group)-based (or CBG-level) PUSCH. DCI format 1_0 is used to schedule TB-based (or TB-level) PDSCH, and DCI format 1_1 is used to schedule TB-based (or TB-level) PDSCH or CBG-based (or CBG-level) PDSCH (DL grant DCI). DCI formats 0_0 / 0_1 are called UL grant DCI or UL scheduling information, and DCI formats 1_0 / 1_1 are called DL grant DCI or DL ​​scheduling information. DCI format 2_0 is used to transmit dynamic slot format information (e.g., dynamic SFI) to the terminal, and DCI format 2_1 is used to transmit downlink pre-emption information to the terminal. DCI format 2_0 and / or DCI format 2_1 are transmitted to terminals within a group via a Group Common PDCCH, which is a PDCCH transmitted to terminals defined within a group.

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

[0054] PDSCH carries downlink data (e.g., DL-SCH transport block, DL-SCH TB), and modulation methods such as QPSK (Quadrature Phase Shift Keying), 16QAM (Quadrature Amplitude Modulation), 64QAM, and 256QAM are applied. TB is encoded to generate a codeword. 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, along with a DMRS (Demodulation Reference Signal), is mapped to a resource and generated as an OFDM symbol signal, which is then transmitted by the corresponding antenna port.

[0055] PUCCH carries UCI (Uplink Control Information). UCI includes the following:

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

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

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

[0059] Table 5 illustrates the PUCCH format. Based on the PUCCH transmission length, it can be classified into Short PUCCH (formats 0 and 2) and Long PUCCH (formats 1, 3, and 4).

[0060] [Table 5]

[0061] PUCCH format 0 carries a UCI up to 2 bits in size and is mapped and transmitted based on a sequence. Specifically, a terminal sends a specific UCI to a base station by sending one of several sequences via PUCCH, which is PUCCH format 0. A terminal sends PUCCH, which is PUCCH format 0, within the PUCCH resource for the corresponding SR configuration only when sending a positive SR.

[0062] PUCCH format 1 carries a UCI up to 2 bits in size, and the modulation symbol is spread in the time domain by an orthogonal cover code (OCC) (which is set differently depending on whether frequency hopping is present or not). DMRS is transmitted with a symbol that is not transmitted (i.e., transmitted using TDM (Time Division Multiplexing)).

[0063] PUCCH format 2 carries UCIs with bit sizes greater than 2 bits, and the modulated symbols are transmitted using DMRS and FDM (Frequency Division Multiplexing). DM-RS symbols are located at symbol indices #1, #4, #7, and #10 within a 1 / 3 density resource block. PN (Pseudo Noise) sequences are used for DM_RS sequences. Frequency hopping can be activated for 2-symbol PUCCH format 2.

[0064] PUCCH format 3 does not perform terminal multiplexing within the same physical resource block and carries UCI with a bit size greater than 2 bits. In other words, PUCCH resources in PUCCH format 3 do not contain orthogonal cover codes. Modulation symbols are transmitted using DMRS and TDM (Time Division Multiplexing).

[0065] PUCCH format 4 supports multiplexing of up to four terminals within the same physical resource block and carries UCIs with bit sizes greater than 2 bits. That is, PUCCH resources in PUCCH format 3 include orthogonal cover codes. Modulation symbols are transmitted using DMRS and TDM (Time Division Multiplexing).

[0066] A terminal can have at least one of its configured cells set up for PUCCH transmission. At least one primary cell can be set up as a cell for PUCCH transmission. Based on at least one cell set up for PUCCH transmission, the terminal has at least one PUCCH cell group, each PUCCH cell group containing one or more cells. A PUCCH cell group is also simply called a PUCCH group. PUCCH transmission can be set up not only on primary cells but also on SCells. Primary cells belong to primary PUCCH groups, and PUCCH-SCells set up for PUCCH transmission belong to secondary PUCCH groups. For cells belonging to primary PUCCH groups, the PUCCH on the primary cell is used, and for cells belonging to secondary PUCCH groups, the PUCCH on the PUCCH-SCell is used.

[0067] 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 CP-OFDM (Cyclic Prefix-Orthogonal Frequency Division Multiplexing) waveform or a DFT-s-OFDM (Discrete Fourier Transform-spread-Orthogonal Frequency Division Multiplexing) waveform. When PUSCH is transmitted based on a DFT-s-OFDM waveform, the terminal applies transform precoding before transmitting PUSCH. For example, if transform precoding is not possible (e.g., transform precoding is disabled), the terminal transmits PUSCH based on a CP-OFDM waveform; if transform precoding is possible (e.g., transform precoding is enabled), the terminal transmits PUSCH based on either a CP-OFDM waveform or a DFT-s-OFDM waveform. PUSCH transmissions are dynamically scheduled by UL grants within DCI, or semi-statically scheduled based on higher-level (e.g., RRC) signaling (and / or Layer 1 (L1) signaling (e.g., PDCCH)). PUSCH transmissions are performed on a codebook-based or non-codebook-based basis.

[0068] Figure 5 illustrates the ACK / NACK transmission process. Referring to Figure 5, the terminal can detect the PDCCH in slot #n. Here, the PDCCH contains downlink scheduling information (e.g., DCI format 1_0, 1_1), and the PDCCH indicates the DL assignment-to-PDSCH offset (K0) and the PDSCH-HARQ-ACK reporting offset (K1). For example, DCI format 1_0, 1_1 includes the following information:

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

[0070] - Time domain resource assignment: 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] - The PDSCH-to-HARQ_feedback timing indicator shows K1.

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

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

[0074] Subsequently, the terminal receives a PDSCH from slot #(n+K0) based on the scheduling information of slot #n. After receiving the PDSCH in slot #n1 (where n+K0≦n1), it transmits a UCI via PUCCH in slot #(n1+K1). Here, the UCI includes a HARQ-ACK response to the PDSCH. In Figure 5, for convenience, it is assumed that the SCS for PDSCH and the SCS for 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 PUCCH.

[0075] If a PDSCH is configured to transmit up to one TB, the HARQ-ACK response consists of 1 bit. If a PDSCH is configured to transmit up to 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 HARQ-ACKs to multiple PDSCHs is specified as slot #(n+K1), the UCI transmitted at slot #(n+K1) will contain HARQ-ACK responses to multiple PDSCHs.

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

[0077] Spatial bundling is supported when the maximum number of TBs (or codewords) that a serving cell can receive at once (or schedule by 1DCI) is two (or more) (for example, when the higher-level parameter maxNrofCodeWordsScheduledByDCI corresponds to 2-TB). On the other hand, more than four layers are used for 2-TB transmission, and up to four layers are used for 1-TB transmission. As a result, when spatial bundling is configured for a cell group, spatial bundling is performed on serving cells within that cell group that can schedule more than four layers. On such a serving cell, a terminal attempting to send a HARQ-ACK response via spatial bundling can generate the HARQ-ACK response by performing a bitwise logical AND operation on the A / N bits for multiple TBs.

[0078] For example, assuming a terminal receives a DCI scheduling 2-TB and receives 2-TB via PDSCH based on that DCI, the terminal performing spatial bundling can generate a single A / N bit by performing a logical AND operation on 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 and second TBs are ACK, the terminal reports the ACK bit value to the base station; if either TB is NACK, the terminal reports the NACK bit value to the base station.

[0079] For example, if only 1-TB is actually scheduled on a serving cell 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 directly to the base station.

[0080] Multiple parallel DL HARQ processes exist at the base station / terminal for DL ​​transmission. These multiple parallel HARQ processes ensure that DL transmissions are performed continuously while waiting for HARQ feedback regarding the success or failure of previous DL transmissions. Each HARQ process is associated with a HARQ buffer in the MAC (Medium Access Control) hierarchy. Each DL HARQ process manages state variables related to the number of MAC PDUs (Physical Data Blocks) transmitted in the buffer, HARQ feedback for MAC PDUs in the buffer, and the current redundancy version. Each HARQ process is distinguished by its HARQ process ID.

[0081] Figure 6 illustrates the PUSCH transmission process. Referring to Figure 6, the terminal can detect PDCCH in slot #n. Here, PDCCH contains uplink scheduling information (e.g., DCI format 0_0, 0_1). DCI format 0_0, 0_1 contains the following information:

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

[0083] - Time domain resource assignment: Indicates 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 SLIV (Start and Length Indicator Value) or are indicated separately.

[0084] Subsequently, the terminal can send a PUSCH message in slot #(n+K2) based on the scheduling information for slot #n. Here, the PUSCH message includes UL-SCH TB.

[0085] CSI-related operations

[0086] Figure 7 shows an example of a procedure related to CSI.

[0087] The terminal receives configuration information related to CSI from the base station via RRC signaling (710). The configuration information related to CSI includes at least one of the following: information about CSI-IM (interference management) resources, information about CSI measurement configuration, information about CSI resource configuration, information about CSI-RS resources, or information about CSI report configuration.

[0088] - CSI-IM resources are configured for interference measurement (IM) of the terminal. In the time domain, CSI-IM resource sets are configured periodically, semi-persistent, or aperiodicly. CSI-IM resources are configured for the terminal as ZP (Zero Power)-CSI-RS. ZP-CSI-RS is configured separately from NZP (Non-Zero Power)-CSI-RS.

[0089] - The UE can assume that the CSI-RS resource for channel measurement and the CSI-IM / NZP-CSI-RS resource for interference measurement (when the NZP-CSI-RS resource is used for interference measurement) set up for one CSI report are in a QCL relationship with respect to 'QCL-TypeD' for each resource.

[0090] - The CSI resource configuration includes at least one of the following: CSI-IM resource for interference measurement, NZP-CSI-RS resource for interference measurement, and NZP-CSI-RS resource for channel measurement. CMR (channel measurement resource) is NZP-CSI-RS for CSI acquisition, and IMR (Interference measurement resource) is NZP-CSI-RS for CSI-IM and IM.

[0091] - CSI-RS may be configured on one or more terminals. Different CSI-RS configurations may be provided for each terminal, or the same CSI-RS configuration may be provided for multiple terminals. CSI-RS can support up to 32 antenna ports. CSI-RS corresponding to N (where N is 1 or more) antenna ports is mapped to N RE locations within a time-frequency unit corresponding to one slot and one RB. If N is 2 or more, the N-port CSI-RS is multiplexed by CDM, FDM and / or TDM schemes. CSI-RS is mapped to REs other than those to which CORESET, DM-RS and SSB are mapped. In the frequency domain, CSI-RS is configured for the entire bandwidth, a portion of the bandwidth (BWP), or a portion of the bandwidth. CSI-RS is transmitted at each RB within the bandwidth in which CSI-RS is configured (i.e., density = 1), or CSI-RS is transmitted at every second RB (e.g., even or odd RBs) (i.e., density = 1 / 2). When CSI-RS is used as a Tracking Reference Signal (TRS), a single-port CSI-RS may be mapped onto three subcarriers in each resource block (i.e., density = 3). One or more CSI-RS resource sets are configured at the terminal in the time domain. Each CSI-RS resource set contains one or more CSI-RS settings. Each CSI-RS resource set is configured periodically, semi-persistent, or aperiodic.

[0092] - CSI reporting settings include settings for feedback type, measurement resources, reporting type, etc. The NZP-CSI-RS resource set is used for the terminal's CSI reporting settings (report configuration). The NZP-CSI-RS resource set may be associated with CSI-RS or SSB. In addition, multiple periodic NZP-CSI-RS resource sets are configured as a TRS resource set. (i) Feedback types include CQI (channel quality indicator), PMI (precoding matrix indicator), CRI (CSI-RS resource indicator), SSBRI (SS / PBCH block resource indicator), LI (layer indicator), RI (rank indicator), L1-RSRP, etc. (ii) Measurement resources include settings for downlink signals and / or downlink resources that the terminal should measure to determine feedback information. Measurement resources are configured as ZP and / or NZP-CSI-RS resource sets associated with the CSI reporting settings. The NZP-CSI-RS resource set includes a CSI-RS set or an SSB set. For example, L1-RSRP is measured against the CSI-RS set or against the SSB set. (iii) The reporting type includes settings for when the terminal reports and for the uplink channel, etc. Reporting timing can be set to periodic, semi-permanent, or aperiodic. Periodic CSI reports are sent over PUCCH. Semi-permanent CSI reports are sent over PUCCH or PUSCH based on MAC CE indicating activation / deactivation. Aperiodic CSI reports are indicated by DCI signaling. For example, the CSI request field of an uplink grant indicates one of several report trigger sizes. Aperiodic CSI reports are sent over PUSCH.

[0093] The terminal measures the CSI based on configuration information related to the CSI. The CSI measurement includes the procedure of receiving the CSI-RS (720) and calculating the received CSI-RS to obtain the CSI (730).

[0094] The terminal transmits a CSI report to the base station (740). The time and frequency resources available to the UE for CSI reporting are controlled by the base station. CSI (channel state information) includes at least one of the following: CQI (channel quality indicator), PMI (precoding matrix indicator), CRI (CSI-RS resource indicator), SSBRI (SS / PBCH block resource indicator), LI (layer indicator), RI (rank indicator), L1-RSRP and / or L-SINR.

[0095] The time domain behavior of CSI reporting supports periodic, semi-persistent, or aperiodic behavior. i) P (periodic)-CSI reporting is performed on short PUCCH and long PUCCH. The periodicity and slot offset of P-CSI reporting are set in RRC and refer to CSI-ReportConfig IE. ii) SP (semi-periodic)-CSI reporting is performed on short PUCCH, long PUCCH, or PUSCH. If SP-CSI is on short PUCCH / long PUCCH, the periodicity and slot offset are set in RRC and CSI reporting is activated / deactivated by a different MAC CE / DCI. When SP-CSI is used on PUSCH, the periodicity of SP-CSI reporting is set by RRC, but the slot offset is not set by RRC, and SP-CSI reporting is activated / deactivated by DCI (format 0_1). A separate RNTI (SP-CSI C-RNTI) is used for SP-CSI reporting on PUSCH. The timing of the first CSI report follows the PUSCH time domain allocation value indicated by DCI, and subsequent CSI report timings follow the period set by RRC. DCI format 0_1 ​​includes a CSI request field and activates / deactivates a predetermined configured SP-CSI trigger state. SP-CSI reporting has the same or similar activation / deactivation as the mechanism that has data transmission on SPS PUSCH. iii) AP-CSI reporting is performed on PUSCH and triggered by DCI. In this case, the information related to the AP-CSI report trigger is communicated / directed / configured by MAC-CE.In the case of AP-CSI with AP-CSI-RS, the AP-CSI-RS reception timing is set by RRC, and the transmission timing for AP-CSI reports is dynamically controlled by DCI.

[0096] QCL (quasi-co location)

[0097] Two antenna ports are quasi-co-located if the channel properties of one antenna port can be inferred from the channels of another antenna port. 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 parameter.

[0098] The terminal is configured with a list of multiple TCI-State configurations via the higher-level parameter PDSCH-Config. Each TCI-State is linked to a QCL configuration parameter between one or two DL reference signals and the PDSCH's DM-RS port. 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:

[0099] -'QCL-TypeA':{Doppler shift, Doppler spread, average delay, delay spread}

[0100] -'QCL-TypeB':{Doppler shift, Doppler spread}

[0101] -'QCL-TypeC':{Doppler shift, average delay}

[0102] -'QCL-TypeD':{Spatial Rx parameter}

[0103] Beam Management (BM)

[0104] The BM process is the process of obtaining and maintaining a set of BS (or transmission and reception point, TRP) and / or UE beams available for downlink (DL) and uplink (UL) transmission / reception, and includes the following processes and terms:

[0105] - Beam measurement: An operation in which a beamforming station (BS) or beamforming engineer (UE) measures the characteristics of the beamforming signal received.

[0106] - Beam determination: The process by which a broadcasting station (BS) or receiver (UE) selects its own transmit beam (Tx beam) and / or receive beam (Rx beam).

[0107] - Beam sweeping: An operation that uses transmitted and / or received beams to cover a spatial domain over a predetermined time interval.

[0108] - Beam report: An operation in which the UE reports information about the beamformed signal based on beam measurements.

[0109] The beam metering (BM) process is divided into (1) DL BM processes using SSB or CSI-RS, and (2) UL BM processes using SRS (Sounding reference signal). Each BM process also includes Tx beam sweeping to determine the Tx beam and Rx beam sweeping to determine the Rx beam.

[0110] In this case, the DLBM process includes (1) transmission of beamformed DL RS (e.g., CSI-RS or SSB) by BS and (2) beam reporting by UE.

[0111] Here, the beam report includes the preferred DL RS ID and its corresponding reference signal received power (RSRP). The DL RS ID is either an SSBRI (SSB Resource Indicator) or a CRI (CSI-RS Resource Indicator).

[0112] M-TRP (multi-transmission and reception point) transmission

[0113] NR Standard Release 17 supports M-TRP PDCCH repetition transmission, M-TRP PDCCH / PDSCH SFN transmission, S-DCI-based M-TRP PUSCH repetition transmission, and single-PUCCH resource-based M-TRP PUCCH repetition transmission.

[0114] All of these transmission techniques are URLLC-targeted enhancements for increased reliability, where the same content (i.e., DCI, UL TB, or UCI) is transmitted repeatedly. In the case of M-TRP PDCCH repetition transmission, it is transmitted repeatedly using TDM or FDM, and M-TRP PDCCH / PDSCH SFN is transmitted repeatedly at the same time / frequency / layer. S-DCI-based M-TRP PUSCH repetition transmission uses TDM, and single-PUCCH resource-based M-TRP PUCCH repetition transmission uses TDM before being transmitted repeatedly.

[0115] - S-DCI-based M-TRP PDCCH repetitive transmission

[0116] In NR Standard Release 17, for M-TRP PDCCH repetition transmission, multiple CORESETs with different TCI states (i.e., different QCL RS) are configured on the UE, and multiple SS (Search Space) sets are configured linked to each of these CORESETs. The base station instructs / configures the UE that the SS sets linked to one CORESET and the SS sets linked to other CORESETs are linked for repetition transmission, so the UE knows that the PDCCH candidates for that SS set will be transmitted repeatedly.

[0117] For example, two CORESETs, CORESET #0 and CORESET #1, are configured in the UE, and each of CORESET #0 and CORESET #1 is linked to SS sets #0 and #1, and SS sets #0 and #1 are linked. The UE can see that the PDCCH candidate in SS set #0 and the PDCCH candidate in SS set #1 repeatedly transmit the same DCI, and that according to a predetermined rule, a specific PDCCH candidate in SS set #0 and a specific PDCCH candidate in SS set #1 are a pair configured to repeatedly transmit the same DCI. These two PDCCH candidates are called linked PDCCH candidates, and the UE can successfully decode the DCI if it correctly receives either of the two PDCCH candidates. However, when receiving a PDCCH candidate for SS set #0, the TCI state QCL RS (i.e., the downlink beam) of CORESET #0 connected to SS set #0 is used, and when receiving a PDCCH candidate for SS set #1, the TCI state QCL RS (i.e., the downlink beam) of CORESET #1 connected to SS set #1 is used, resulting in linked PDCCH candidates being received on different beams.

[0118] - M-TRP SFN PDCCH

[0119] As a special case of M-TRP PDCCH repeated transmission, multiple TRPs can repeatedly transmit the same DCI at the same time / frequency / DM-RS port; this is called SFN PDCCH transmission. However, for SFN PDCCH transmission, instead of setting up multiple CORESETs with different TCI states, the base station sets up multiple TCI states in a single CORESET. When the UE receives a PDCCH candidate via an SS set linked to that single CORESET, it attempts to estimate and decode the PDCCH DM-RS channel using any of the multiple TCI states.

[0120] - M-TRP SFN PDSCH

[0121] During the M-TRP PDSCH repeated transmission described above, the two TRPs repeatedly transmit the channel to different resources. However, in a special case, even when the resources used by the two TRPs are the same, i.e., when the same channel is repeatedly transmitted at the same frequency, time, and layer (or DM-RS port), the reliability of the channel can be improved. In this case, the same channel that is repeatedly transmitted is received together on the air without resource separation, and is therefore recognized as a single channel at the receiving end. The NR standard sets two downlink TCI states for PDSCH DM-RS reception in order to transmit PDSCH SFN.

[0122] - S-DCI-based M-TRP push repetition transmission

[0123] The base station configures two SRS sets on the UE for S-DCI-based M-TRP push transmission, with each SRS set used to indicate the uplink transmit ports and uplink beam / QCL information directed to TRP #1 and TRP #2. The base station can also indicate SRS resources for each SRS set using two SRI fields in a single DCI, and can indicate up to two power control (PC) parameter sets. For example, the first SRI field indicates the SRS resources and PC parameter set defined in set 0, and the second SRI field indicates the SRS resources and PC parameter set defined in set 1.

[0124] The UE is instructed by the first SRI field to specify the uplink transmit port, PC parameter set, and uplink beam / QCL information for TRP #1, thereby performing a push transmission at the TO corresponding to SRS set #0. Similarly, the UE is instructed by the second SRI field to specify the uplink transmit port, PC parameter set, and uplink beam / QCL information for TRP #2, thereby performing a push transmission at the TO corresponding to SRS set #1.

[0125] - M-TRP PUCCH repeated transmission based on a single PUCCH resource

[0126] For M-TRP PUCCH transmission based on a single PUCCH resource, the base station activates / configures two spatial relation info for the single PUCCH resource to the UE, and when the UE transmits UL UCI via that PUCCH resource, each of the spatial relation info is used to indicate the spatial relation info toward TRP #1 and TRP #2.

[0127] For example, the value indicated in the first spatial relation info instructs the UE to transmit beam / PC parameters toward TRP #1, and uses this information to perform a PUCCH transmission at the TO corresponding to TRP #1. Similarly, the value indicated in the second spatial relation info instructs the UE to transmit beam / PC parameters toward TRP #2, and uses this information to perform a PUCCH transmission at the TO corresponding to TRP #2.

[0128] At the Rel 17 standardization meeting, the configuration method was enhanced so that two spatial relation information pieces are set in the PUCCH resource for repeated transmission of M-TRP PUCCH. Specifically, if PC parameters are set for each spatial relation information piece, the spatial relation RS can be set. As a result, the PC information and spatial relation RS information corresponding to two TRPs can be set using two spatial relation information pieces, and the UE transmits using the first spatial relation information piece via PUCCH at TO 1, and transmits using the second spatial relation information piece via the same UCI (i.e., CSI, ACKNAK, SR) PUCCH at TO 2.

[0129] Hereinafter, a PUCCH resource with two spatial relation info settings will be referred to as an M-TRP PUCCH resource, and a PUCCH resource with one spatial relation info setting will be referred to as an S-TRP PUCCH resource.

[0130] Meaning of TCI status / beam indication

[0131] When receiving data / DCI / UCI for any frequency / time / space resource, using or mapping a specific TCI state (or TCI) means, in the case of a downlink, estimating the channel from the DM-RS using the QCL type and QCL RS indicated by the downlink TCI state for that frequency / time / space resource, and then receiving / demodulating the data / DCI on the estimated channel.

[0132] In the case of an uplink, this means transmitting / modulating DM-RS and data / UCI using the transmit beam and / or transmit power indicated by the uplink TCI state within that frequency / time / space resource.

[0133] The uplink TCI state includes the UE's transmit beam or transmit power information. Instead of the TCI state, spatial relation information or other parameters may be used to set the UE.

[0134] The uplink TCI state may be directly indicated by the DCI that transmits the uplink grant, or it may mean spatial relational information of the SRS resource indicated by the SRI field of the UL grant DCI. Alternatively, it may mean an open-loop transmit power control parameter coupled to a value indicated by the SRI field of the UL grant DCI. Alternatively, the uplink TCI may be indicated using a DL grant DCI.

[0135] AI / ML(Artificial intelligence / machine learning)

[0136] The advancement of AI / ML technology will lead to the intelligence and sophistication of nodes and terminals that constitute wireless communication networks. In particular, the intelligence of networks and base stations is expected to enable the rapid optimization, derivation, and application of various network / base station determination parameter values ​​(e.g., transmit / receive power of each base station, transmit power of each terminal, base station / terminal precoder / beam, time / frequency resource allocation for each terminal, multiplexing (duplex) method of each base station) according to various environmental parameters (e.g., distribution / location of base stations, distribution / location / material of buildings / furniture, terminal location / movement direction / speed, climate information, etc.). Following this trend, many standardization groups (e.g., 3GPP, O-RAN) are considering its introduction, and research in this area is actively underway.

[0137] While AI / ML can be broadly defined as deep learning-based artificial intelligence, conceptually it is as shown in Figure 8.

[0138] - Artificial Intelligence: This refers to all automation that allows machines to perform tasks that humans would normally have to do.

[0139] - Machine Learning: Without explicitly programming rules, machines learn patterns for decision-making from data on their own.

[0140] - Deep Learning: An AI / ML model based on artificial neural networks, in which the machine performs feature extraction and decision-making from unstructured data in a single step. The algorithm relies on a multi-layer network composed of interconnected nodes for feature extraction and transformation, inspired by the biological nervous system, i.e., neural networks. Common deep learning network architectures include deep neural networks (DNNs), recurrent neural networks (RNNs), and convolutional neural networks (CNNs).

[0141] Classification of AI / ML types based on various criteria

[0142] 1. Offline vs. Online

[0143] (1) Offline Learning: This method involves sequentially following the procedures of database collection, training, and prediction. Specifically, data collection and training are performed offline, and the completed program is installed on-site and used for prediction work. In most situations, this offline learning method is used.

[0144] (2) Online Learning: Recently, online learning has come about by taking advantage of the fact that data usable for learning is continuously generated via the internet, and by using this generated data to gradually increase and add to the learning process, thereby slowly improving performance.

[0145] 2. Classification based on AI / ML framework concepts

[0146] (1) Centralized Learning: Training data collected from multiple different nodes is reported to a centralized node, and all data resources / storage / learning (e.g., supervised, unsupervised, reinforcement learning) are performed on a single central node.

[0147] (2) Federated Learning: Collective AI / ML models are constructed based on data distributed among data owners. Instead of bringing data to the AI / ML model, the AI / ML model is brought to the data source, and local nodes / individual devices collect the data and train their own copies of the AI / ML model, eliminating the need to report source data to a central node. In Federated Learning, the parameters / weights of the AI / ML model can be retransmitted to the centralized node to support the training of the general AI / ML model. The advantages of Federated Learning are increased computation speed and superior information security. In other words, since the process of uploading personal data to a central server is unnecessary, the leakage and misuse of personal information can be prevented.

[0148] (3) Distributed Learning: This refers to the concept in which the machine learning process is extended and distributed across the entire node cluster. The training AI / ML model is shared among multiple nodes that are divided and operate simultaneously to increase the speed of AI / ML model training.

[0149] 3. Classification by learning method

[0150] (1) Supervised Learning: Supervised learning is a machine learning operation that aims to learn the mapping function from input to output, given a dataset with specified labels. The input data is called training data and has known labels or results. Examples of supervised learning include (i) Regression: Linear Regression, Logistic Regression, (ii) Instance-based Algorithms: k-Nearest Neighbor (KNN), (iii) Decision Tree Algorithms: CART, (iv) Support Vector Machines: SVM, (v) Bayesian Algorithms: Naive Bayes, and (vi) Ensemble Algorithms: Extreme Gradient Boosting, Bagging: Random Forest, etc. Supervised learning can be further grouped by regression and classification problems, where classification is predicting labels and regression is predicting quantities.

[0151] (2) Unsupervised Learning: This is a machine learning process that aims to learn the ability to explain hidden structures in data that has not been labeled. The input data has no labels and there are no known results. Some examples of unsupervised learning include K-means clustering, principal component analysis (PCA), nonlinear independent component analysis (ICA), and LSTM.

[0152] (3) Reinforcement Learning: In reinforcement learning (RL), the agent aims to optimize long-term goals by interacting with the environment based on a trial-and-error process, and is goal-oriented learning based on interaction with the environment. Examples of RL algorithms include (i) Q-learning, (ii) Multi-armed bandit learning, (iii) Deep Q Network, State-Action-Reward-State-Action (SARSA), (iv) Temporal Difference Learning, (v) Actor-critic reinforcement learning, (vi) Deep deterministic policy gradient, and (vii) Monte-Carlo tree search. Reinforcement learning can be further grouped into AI / ML model-based reinforcement learning and AI / ML model-free reinforcement learning. Model-based reinforcement learning is an RL algorithm that uses predictive AI / ML models, obtaining switching establishments between states using various dynamic states of the environment and AI / ML models that lead to compensation for such states. Model-free reinforcement learning is a value or policy-based RL algorithm that achieves the greatest future compensation, and in multi-agent environments / states, it is necessary to accurately represent the environment without computational complexity. On the other hand, RL algorithms can also be classified into categories such as value-based RL versus policy-based RL, policy-based RL versus non-policy RL, and so on.

[0153] AI / ML Model

[0154] Figure 9 illustrates an FFNN (Feed-Forward Neural Network) AI / ML model. Referring to Figure 9, the FFNN AI / ML model includes an input layer, a hidden layer, and an output layer.

[0155] Figure 10 illustrates an RNN (Recurrent Neural Network) AI / ML model. Referring to Figure 10, an RNN AI / ML model is a type of artificial neural network in which hidden nodes are connected by directional edges, forming a directed cycle structure. It is an AI / ML model suitable for processing sequentially appearing data such as speech and text. One type of RNN is LSTM (Long Short-Term Memory), which is a structure in which cell states are added to the hidden states of an RNN. Specifically, in an LSTM, input gates, forget gates, and output gates are added to the RNN cells, and cell states are added.

[0156] Figure 11 illustrates a CNN (Convolutional Neural Network) AI / ML model. CNNs are used for two purposes: to reduce the complexity of AI / ML models and to extract good features, by applying convolution operations commonly used in the fields of video and image processing. Referring to Figure 11, a kernel or filter refers to a unit / structure that applies weighted values ​​to an input within a given range / unit. Stride refers to the range of movement of the kernel within the input. Feature map refers to the result of applying the kernel to the input. Padding refers to the value added to adjust the size of the feature map. Pooling refers to operations (e.g., max pooling, average pooling) that downsample the feature map to reduce its size.

[0157] Figure 12 shows an autoencoder AI / ML model. Referring to Figure 12, an autoencoder is a neural network that takes a feature vector x as input and outputs the same or similar vector x', where the input and output nodes have the same features, and is a type of unsupervised learning.

[0158] Figure 13 is a diagram illustrating the 3GPP RAN (radio access network) intelligence framework.

[0159] The following definitions are used for terms related to AI / ML (see 3GPP TS37.817).

[0160] - Data collection: Data collected from network nodes, management entities, or terminals, which forms the basis for ML AI / ML model training, data analysis, and inference.

[0161] - ML Model: A data-driven algorithm that generates a set of output consisting of predicted information based on a set of inputs by applying ML methods.

[0162] - ML training: This is an online or offline process of learning the features and patterns that best represent the data, training an ML AI / ML model, and obtaining the trained ML AI / ML model for inference.

[0163] - ML inference: This is the process of using trained ML AI / ML models to guide predictions or decisions based on collected data and the ML AI / ML models themselves.

[0164] Referring to Figure 13, data collection is the function that provides input data to the AI / ML model training and AI / ML model inference functions. Data preparation for each AI / ML algorithm (e.g., data preprocessing and organization, formatting, and transformation) is not performed by the data collection function.

[0165] Examples of input data include measurements of UEs or other network entities, actor feedback, and AI / ML model outputs. Training data is the data required as input for the AI / ML model training function. Inference data is the data required as input for the AI / ML model inference function.

[0166] AI / ML model training is part of the AI / ML model testing procedure and is a function that performs AI / ML model training, validation, and testing capable of generating AI / ML model performance metrics. If necessary, the AI / ML model training function can also be responsible for data preparation (e.g., data preprocessing and organization, formatting, and transformation) based on the training data provided by the data collection function.

[0167] AI / ML Model Deployment / Update: Used to initially distribute trained, validated, and tested AI / ML models to the AI / ML model inference function, or to transmit updated AI / ML models to the AI / ML model inference function.

[0168] Model inference is a function that provides AI / ML model inference output (e.g., prediction or decision). Depending on the case, the AI / ML model inference function may also provide AI / ML model performance feedback to the AI / ML model training function. If necessary, the AI / ML model inference function may also perform data preparation (e.g., data preprocessing and organization, formatting, and transformation) based on the inference data transmitted by the data acquisition function. Output refers to the inference output of the AI / ML model generated by the AI / ML model inference function. AI / ML model performance feedback is used to monitor the performance of the AI / ML model.

[0169] An actor is a function that receives the output of an AI / ML model inference function and triggers or executes that action. Actors trigger actions directed at other entities or themselves. Feedback is the information necessary to derive training or inference data or performance feedback.

[0170] dataset

[0171] The data used in AI / ML includes at least one of the following: AI / ML model training data, validation data, and test data.

[0172] AI / ML model training data is a dataset used to train an AI / ML model.

[0173] Validity data is a dataset used to validate AI / ML models that have already completed training. It is used to prevent overfitting of AI / ML model training datasets. It may also be a dataset used to select the best AI / ML model from among the various models trained during the training process, and therefore can be considered a type of training.

[0174] The test data is a dataset for the final evaluation and does not necessarily need to be related to the training process.

[0175] For example, AI / ML model training data and validation data may be used in an 8:2 or 7:3 ratio, or if test data is also considered, a 6:2:2 ratio (training:validation:test) may be used.

[0176] Collaboration level

[0177] As an example, the level of cooperation (or category) is defined as follows, depending on whether AI / ML functionality is available between the base station and the terminal, and variations are possible through the combination or separation of the following levels.

[0178] Cat 0a) No collaboration framework: AI / ML algorithms are implemented, but no changes are required on the wireless interface.

[0179] A modified interface is provided to realize a more efficient AL / ML Alfort than Cat 0b).

[0180] Cat 1) Inter-node cooperation is possible to improve the AL / ML algorithms of each node. Terminals can receive or provide assistance from the base station for training, adaptation, etc. However, the exchange of AI / ML model information between network nodes is not required.

[0181] Cat 2) Joint AI / ML operation between terminals and base stations, requiring instructions / exchanges between network nodes.

[0182] TD (Time Domain) Compressed Codebook

[0183] Figures 14 and 15 show an example of reporting PMI for multiple time instances.

[0184] In particular, the PMI shown in Figures 14 and 15 ref_rsc PMI ref_rsc+τ and PMI ref_rsc+2τ It is compressed based on the TD (Time Domain) compression codebook to reduce PMI feedback overhead.

[0185] As shown in Figures 14 and 15, the base station signals the UE in the following way to determine the time instance of the channel represented by PMI. One example of this signaling is indicated by the RRC signaling parameters for codebook configuration.

[0186] First, the number of time instances to represent in PMI is specified. In Figures 14 and 15, the number of time instances is three. The number of time instances is set considering the time variation of the channel, and for this purpose, the UE reports its speed information, Doppler information (Doppler shift / spread), etc. to the base station. Alternatively, the UE reports its preferred number of time instances to the base station based on its speed or Doppler information, and the base station confirms or makes a final selection. The UE reports candidate values ​​for the number of time instances as UE capability.

[0187] Furthermore, Figures 14 and 15 indicate the interval τ value between each time instance. The τ value is set considering the time variation of the channel, and for this purpose, the UE reports its velocity information, Doppler information (Doppler shift / spread), etc., to the base station. Alternatively, the UE reports a preferred τ value to the base station based on its velocity or Doppler information, and the base station confirms or makes a final selection. The τ value is expressed as absolute time, slot OFDM symbol, etc. The UE reports candidate values ​​for the τ value as UE capability.

[0188] This indicates which of the time instances configured as described above the CSI reference resource corresponds to.

[0189] In FIG. 14, among the three time instances, the CSI reference resource is set for the first time instance, and for this reason, the base station sets the time instance offset of the CSI reference resource to 0. As the CSI reference resource is set for the first time instance, the remaining time instances at subsequent points are set after the CSI reference resource. In FIG. 15, among the three time instances, the CSI reference resource is set for the last (third) time instance, and for this reason, the base station sets the time instance offset of the CSI reference resource to 2. As the CSI reference resource is set for the third time instance, the remaining time instances at the previous points are set before the CSI reference resource.

[0190] The time instance offset is set in consideration of the time-varying nature of the channel. For this reason, the UE reports its speed information, Doppler information (Doppler shift / spread), etc. to the base station. Alternatively, the UE reports to the base station the time instance offset it prefers from its own speed or Doppler information, and the base station confirms this or makes the final selection. Also, depending on the UE implementation, as shown in FIG. 14, the UE that can set the time instance offset to other time instances than the last time instance, and as shown in FIG. 15, the UE that can set the time instance offset only to the last time instance are distinguished, and this is reported as UE capability information. The latter does not need to perform channel prediction, so the implementation is simple, but the former needs to perform channel prediction, so the implementation is complex.

[0191] More specifically, in the case of the former, it is possible to additionally report the minimum value of the setable time instance offset or the candidates for the setable time instance offset values. Since more channel prediction needs to be performed as the minimum value is smaller, the UE implementation becomes more complex.

[0192] <CSI Overhead Reduction Method>

[0193] In the method for reporting PMI for multiple time instances as described in Figures 14 and 15 above, if the uplink resource reporting the CSI (e.g., PUCCH resource / PUSCH resource) is set to be smaller than the CSI payload, it is necessary to reduce the PMI feedback overhead.

[0194] 1. One possible method for reducing feedback overhead is to report PMI with different levels of accuracy for each of the multiple time instances.

[0195] (1) First, when reporting one W1 that applies to multiple time instances in common and multiple W2s that apply to each of the multiple time instances without TD (Time Domain) compression, the following methods a) to c) can be considered.

[0196] (1)-(a) Omission of W2 reporting for specific time instances. Specific time instances include odd-numbered time instances (or even-numbered time instances), the most recent time instances (e.g., the most recent N / 2 time instances out of N time instances), or other time instances.

[0197] Alternatively, a specific time instance refers to the time instances from the most recent time instance L, when W2 is omitted in reverse chronological order (i.e., L-1, L-2, ...), until the CSI payload is sent to the uplink resource. Conversely, it refers to the time instances from the first time instance, when W2 is omitted in chronological order (i.e., the second time instance, the third time instance, ...), until the CSI payload is sent to the uplink resource.

[0198] Nevertheless, if uplink resources are insufficient, only W2 for a specific time instance (e.g., W2 calculated using the conventional method based on conventional CSI reference resources) will be reported.

[0199] (1)-(b) Instead of omitting W2 reporting for specific time instances, you can also reduce the payload size by adjusting the W2 parameters for specific time instances.

[0200] For example, you can reduce the granularity of the amplitude (non-zero coefficient) of the NZC (i.e., reduce the number of bits used to indicate amplitude), reduce the granularity of the phase (e.g., reduce from 16PSK to 8PSK to reduce the number of bits), reduce the number of NZCs, or reduce the upper limit (K0) of the number of NZCs. You can also reduce the W2 payload by omitting some NZCs from the CSI report (e.g., omitting NZCs with small amplitude values ​​from the CSI report), or by reducing the number (M) of the Frequency Domain (FD) basis vectors.

[0201] Alternatively, the number of layers can be reduced for a specific time instance to decrease the W2 payload and report it. For example, when RI=2 is determined and PMI is reported for t1, t2, and t3, a W2 report for RI=2 should be reported for each time instance, but the W2 report for a specific layer in a specific time instance can be omitted to reduce the payload.

[0202] When W2 for t1, t2, and t3 are denoted as W2(t1), W2(t2), and W2(t3), respectively, if RI is 2, then W2(t1), W2(t2), and W2(t3) each basically need to calculate / report PMI for 2 layers, 2 layers, and 2 layers. If this is shown in 2-2-2, then if there are insufficient uplink resources, CSI can be omitted in the order of 2-2-1 -> 2-1-1 -> 1-1-1 -> 1-1-0 -> 1-0-0 -> 0-0-0. Alternatively, CSI can be omitted in the order of 2-2-2 -> 2-2-1 -> 2-2-0 -> 2-1-0 -> 2-0-0 -> 1-0-0 -> 0-0-0.

[0203] (1)-(c) On the other hand, as a combination of (1)-(a) and (1)-(b) described above, if there are still insufficient uplink resources after performing (1)-(b), (1)-(a) can be applied to omit the W2 report. Alternatively, if there are still insufficient uplink resources after applying (1)-(a), (1)-(b) can be applied to the other W2s that have not been omitted to lower the W2 payload and report them.

[0204] (2) Next, when using a TD compressed codebook, the PMI for multiple time instances is represented in a single codebook. That is, the PMI for multiple time instances is represented at once by a linear combination of TD basis vectors. For example, since the number of time instances is the same as the number of TD basis vectors, time instances 0 through 3 are represented by a linear combination of TD basis vectors of length 4, and as a result, the i-th element of the linearly combined TD basis vectors represents the PMI for the i-th time instance. In this case as well, the above-mentioned (1)-(a) to (1)-(c) can be extended and applied as follows.

[0205] (2)-(a) When (1)-(a) is extended and applied to a TD compressed codebook, PMI reporting is omitted for certain time instances, and as a result, those time instances are excluded from the TD basis vector. For example, if time instances 0 through 3 are configured to use a TD basis vector of length 4, and PMI for even-numbered time instances is omitted from the CSI report, then a TD basis vector of length 2 must be used for time instances 1 and 3.

[0206] The number of TD basis vectors, N, is proportional to the length of the TD basis vectors (for example, N is the length of the TD basis vectors / 4), and as the length of the TD basis vectors (i.e., the number of time instances) decreases, N also decreases. Furthermore, as N decreases, the PMI payload decreases as follows:

[0207] Specifically, an NZC is selected for each layer using a 2L*M*N bitmap. Here, 2L is the number of SD (Spartial Domain) basis vectors, M is the number of FD (Frequency Domain) basis vectors, and N is the number of TD basis vectors. In this case, as N decreases, the size of the bitmap per layer decreases. Also, the upper limit K0 of KNZ (i.e., the number of NZCs) per layer can be determined in proportion to 2L*M*N (for example, K0 = 2L*M*N / 8), and as N decreases, K0 also decreases, and KNZ decreases. Since amplitude and phase need to be reported for each NZC, a decrease in KNZ (the number of NZCs) results in a decrease in the PMI payload.

[0208] (2)-(b) When applying (1)-(b) to a TD compressed codebook, the payload can be reduced by adjusting the PMI parameters for a particular time instance. For example, the payload of W2 can be reduced by lowering the amplitude granularity of NZCs (i.e., reducing the number of bits used to indicate amplitude), lowering the phase granularity of NZCs (e.g., from 16PSK to 8PSK), lowering the number of NZCs, lowering the upper limit K0 for the number of NZCs, omitting some NZCs from the CSI report (e.g., omitting NZCs with small amplitude values ​​from the CSI report), or reducing the number of Frequency Domain (FD) basis vectors (M).

[0209] Alternatively, the time instances of PMI to be reported can be configured differently for each layer. For example, when the RI is 4, the first layer reports PMI for all time instances (in this case, the TD compressed codebook may be applied, or W2 may be reported for each time instance without applying the codebook), the second layer reports PMI for even-numbered time instances, the third layer reports PMI for even-numbered time instances among those reported by the second layer (i.e., the third layer reports CSI for half of the time instances of the second layer), and the fourth layer reports PMI for even-numbered time instances among the time instances of the third layer. Alternatively, the third and fourth layers may also report PMI for the same time instances as the second layer.

[0210] Alternatively, the first layer reports PMIs for all time instances, the second layer reports PMIs for the first half of the time instances in chronological order, the third layer reports PMIs for half of the first half of the time instances in chronological order, and the second layer reports PMIs for half of the first half of the time instances in chronological order.

[0211] (2)-(c) On the other hand, as a combination of (2)-(a) and (2)-(b) described above, if there are still insufficient uplink resources after performing (2)-(b), (2)-(a) can be applied to omit the W2 report. Alternatively, if there are still insufficient uplink resources after applying (2)-(a), (2)-(b) can be applied to the other W2s that have not been omitted to lower the W2 payload and report it.

[0212] 2. A second method for reducing feedback overhead is to omit reporting the NZC (non-zero coefficient) for specific TD basis vectors when using a TD compressed codebook.

[0213] Specifically, the process of omitting NZC in conventional FD compression codebooks will be extended and applied to TD compression codebooks. First, the process of omitting NZC in conventional FD compression codebooks will be explained, and the proposed method will be described later.

[0214] In the conventional CSI omission method, the NZC report for specific FD basis vectors using a Type II codebook can be omitted by the following equation 1, thereby reducing the payload size, as disclosed in 3GPP 38.314 section 5.2.3.

[0215] [Formula 1]

number

[0216] According to Equation 1 above, the NZC of a specific FD beam, i.e., an FD beam far from the FD beam with index 0 by π(f), will have a higher Pri(l,i,f) value than the NZC of other FD beams. Since a higher Pri(l,i,f) value indicates a lower priority, the NZC of the aforementioned specific FD beam will be omitted from the NZC report. For the same FD beam, the NZC will have a lower priority as the SD beam index increases, and for the same FD beam and the same SD beam, the NZC will have a lower priority as the layer index increases. Here, SD beam and FD beam refer to the SD basis vector and FD basis vector, respectively.

[0217] Furthermore, we propose modifying Equation 1 above so that the priority of NZC is determined not only for the FD basis vector index (f), the SD basis vector index (i), and the layer index (l), but also for the TD basis vector index (t), i.e., the TD beam index, as follows. Also, υ is the number of layers, and 2L is the number of SD basis vectors.

[0218] 2-(1) First, the priority of NZC can be determined by the following formula 2.

[0219] [Formula 2]

number

[0220] υ is a value related to the number of layers, 2L is the number of SD basis vectors, N3 is the number of FD basis vectors, and π'(t) is a function that determines the priority for the t-th TD basis vector, where t is 0, 1, 2, ..., N-1, and N is the number of TD basis vectors. More simply, π'(t) may be a function that maps t to integer values ​​between 0, 1, 2, ..., N-1 in a one:1 manner.

[0221] For example, when mapping t to t in a 1:1 manner, the preceding TD basis vector has a higher priority than the following TD basis vector. Conversely, when mapping t=0, 1, 2, ..., N-1 to N-1, N-2, N-3, ..., 0 in a 1:1 manner, the following TD basis vector has a higher priority than the preceding TD basis vector. Alternatively, when t is even, it is mapped to a smaller value than when t is odd, and for both even and odd t values, the preceding TD basis vector is mapped to a smaller (or larger) value. In this case, the TD basis vectors with even indices have a higher priority.

[0222] Alternatively, π'(t) may be a function that maps t to integer values ​​between 0 and N4-1 in a one-to-one manner. That is, we can also show π'(t) = t. N4 is the number of time instances, which is the same as the length of the TD basis vectors, and N TD basis vectors can be generated by selecting N vectors in a DFT matrix of size (N4*N4).

[0223] To simplify this, a larger Pri(l,i,f,t) value results in a lower priority, so NZC for a particular TD beam is omitted earlier in the NZC report. For the same TD beam, an NZC with a larger FD beam index has a lower priority, and for the same TD beam and the same FD beam, an NZC with a larger SD beam index has a lower priority. For the same TD beam, the same FD beam, and the same SD beam, an NZC with a larger layer index has a lower priority. Here, SD beam and FD beam refer to the SD basis vector and FD basis vector, respectively.

[0224] While π'(t) is simply assumed to be a single permutation scheme, the permutation scheme changes depending on the terminal's movement speed, direction, etc. After pre-setting multiple permutation schemes, an indicator indicating which scheme was used can be considered as a new feedback factor. Alternatively, permutation information can be communicated using a combinational number or similar method.

[0225] Based on the priority of NZC determined by equation 2 above, a group of NZC values ​​(i.e., amplitude and / or phase) is determined, and each group also includes a bitmap for the NZCs belonging to that group (i.e., a bitmap that distinguishes NZC from ZC among 2L*M*N coefficients). For example, according to the priority, half of the NZCs corresponding to the higher priority are assigned to group 1, and the other NZCs to group 2. If NZCs are omitted for all TD basis vectors, the PMI is reported using a conventional codebook for one time instance (e.g., a conventional CSI reference resource slot) instead of a TD compressed codebook, and the conventional CSI omission rules are applied to that conventional codebook to determine the CSI payload.

[0226] 2-(2) Next, the priority of NZC can be determined by the following formula 3.

[0227] [Formula 3]

number

[0228] π'(t) is the same as that defined in Equation 2. However, Equation 3 is obtained by changing the order of application of the priority order of the FD basis vectors and TD basis vectors corresponding to f and t in Equation 2.

[0229] In other words, in equation 2, the priority of NZC is determined first by the TD basis vector, and then the priority is determined by the FD basis vector for the same TD basis vector. On the other hand, in equation 3, the priority of NZC is determined first by the FD basis vector, and then the priority is determined by the TD basis vector for the same FD basis vector.

[0230] In equation 3, we assume that π'(t) is a function that outputs values ​​between 0 and N-1. However, if π'(t) is a function that outputs values ​​between 0 and N4-1, then we need to change N to N4 in equation 3.

[0231] If NZC is omitted for all FD basis vectors, PMI will be reported using the WB codebook instead of the FD compressed codebook, and the CSI omission process can be applied to the WB codebook by setting π(f) in Equation 3 to 0. That is, the WB PMI will be reported for multiple time instances using the TD compressed codebook, but if there are insufficient uplink resources, the NZC of the lower-priority TD basis vectors will be omitted first. If both the NZC of the FD basis vectors and the NZC of the TD basis vectors are omitted, PMI will be reported using the conventional WB codebook for one time instance (e.g., a conventional CSI reference resource slot).

[0232] 2-(3) If we use the conventional rule, Equation 1, as is, Equation 1 does not take into account TD basis vectors, so there may be multiple NZCs with the same priority. Therefore, we propose a method to determine the priority among multiple NZCs with the same priority using the index of the TD basis vector.

[0233] For example, assuming that in equation 1 there are three NZCs where π(f), f,i,l are identical and have the same priority, and that each NZC is a coefficient for TD basis vector 1 to TD basis vector 3, then the priority of the three NZCs is determined according to the priority of the TD basis vectors determined using π' from 2-(1) above.

[0234] After priorities are determined in this way, half of the NZCs with high priority can be placed in Group 1, as in the past, and the remaining NZCs can be placed in Group 2.

[0235] Furthermore, the NZC of some TD basis vectors can be set to 0 (i.e., omitted), and the proposal in 2-(3) can be applied. That is, if there are insufficient uplink resources, some TD basis vectors corresponding to NZC are selected, the NZC of those TD basis vectors is omitted first, and then the proposal in 2-(3) is applied. In this case, the selection of some TD basis vectors is determined by even-numbered TD basis vectors (or odd-numbered TD basis vectors), the first TD basis vector (or the second TD basis vector) obtained by halving the TD basis vectors, or TD basis vectors with small coefficient amplitudes.

[0236] 2-(4) Priority can be determined by applying both Equation 2 and Equation 3. For example, Equation 2 can be applied first to omit half (or some) of the NZCs corresponding to lower priority, and if there are still insufficient uplink resources, Equation 3 can be applied to the remaining NZCs to omit half (or some) of the NZCs corresponding to lower priority. In this process, some NZCs for lower priority TD basis vectors are omitted first, and then some NZCs for lower priority FD basis vectors are omitted. Of course, Equation 3 can also be applied first to omit some NZCs, and then Equation 2 can be applied.

[0237] The BS can set the UE to determine which of the above formulas (1 to 3) is used to apply the NZC omission.

[0238] 3. As a third method for reducing feedback overhead, when using TD compressed codebooks, we propose reducing PMI feedback overhead by setting a smaller upper limit K0 for the number of NZCs.

[0239] In conventional Type II codebooks, the upper limit of the NZC number is set so that K0 = 2L * M * beta for each layer. Here, beta is a constant that is greater than 0 and less than 1, or equal to 1.

[0240] In the TD compression codebook, 2L*M*N coefficients (NZC or ZC) are defined per layer based on the number of TD basis vectors N. Reflecting this, if the upper limit K0 for the number of NZCs per layer is set to 2L*M*N*beta, the overhead increases excessively as the value of N increases. To reduce this increase in overhead, beta can be set to decrease as N increases. For example, if TD compression is not used, N=1 is set to K0=2L*M*N*beta and the conventional beta value is applied. On the other hand, if TD compression is used, i.e., for N>1, a value smaller than the conventional beta value is applied.

[0241] Alternatively, the beta value can be kept the same, but an alpha value can be added, thereby achieving similar behavior. For example, if K0 is determined to be 2L*M*N*beta*alpha, and TD compression is not used, N is set to 1, the conventional beta value is applied, and alpha is set to 1. On the other hand, if TD compression is used, i.e., for N>1, the conventional beta value is used, and an alpha value less than 1 is applied. Furthermore, alpha can be set to decrease as N increases.

[0242] Furthermore, the current 3GPP NR standard limits the sum of the number of NZCs across all layers to 2K0 to prevent an excessive increase in the number of NZCs as the rank increases. This limit can be set more strictly when using TD compressed codebooks. For example, the sum of the number of NZCs across all layers can be limited to m*K0 (e.g., m<2 and m=1).

[0243] When reporting a single W1 that applies to multiple time instances in common and multiple W2s that apply to each of those time instances without TD (Time Domain) compression, the feedback payload can be adjusted by applying different beta values ​​to each of the multiple time instances. Specifically, a large beta value can be applied to one slot (e.g., a traditional CSI reference resource slot) among the multiple time instances, while smaller values ​​can be applied to the other time instances, thereby reducing the number of NZCs. Alternatively, it is possible to apply larger beta values ​​to time instances in chronological order, such as applying larger beta values ​​to time instances further in the past, or conversely, to time instances further in the future. Since CSI calculations for future time instances may be inaccurate, it is preferable to reduce the beta.

[0244] 4. According to conventional technology, a base station can set a Codebook subset restriction (CBSR) to prevent certain PMIs from being reported to the UE. For example, a base station can set a restriction on SD beams that the UE can report for interference management purposes, and set an amplitude (or power) limit for specific SD beams.

[0245] As a fourth method for reducing feedback overhead, we propose setting different CBSRs for each time instance when PMI is reported for multiple time instances. This is because the base station will perform different interference management for each time instance.

[0246] For example, a base station can be configured not to report SD beam 0 and SD beam 1 to the UE, and SD beam 1 and SD beam 2 to the UE, in order to not perform downlink transmission using SD beam 0 and SD beam 1 at t1, and not to perform downlink transmission using SD beam 1 and SD beam 2 at t2. More specifically, the base station can set the maximum allowed average amplitude at t1 and the maximum allowed average amplitude at t2. The maximum allowed average amplitude can be replaced with the maximum allowed average power.

[0247] In addition to limiting each SD beam and / or power for each time instance, TD basis vectors can also be limited. Since applying TD basis vector limitations to all SD beams may seem excessive, it is preferable to operate them in conjunction with specific SD beams. For example, TD basis vectors 0 through 3 may be restricted from being used for SB beamset 1, and TD basis vectors 4 through 7 may be restricted from being used for SB beamset 2.

[0248] Figure 16 is a flowchart showing how the CSI for multiple-time instances is reported according to this disclosure.

[0249] Referring to Figure 16, in step A05, the UE receives a control signal from the BS for CSI reporting. The control signal includes information about the CMR (channel measurement resource) and / or information about the uplink grant for reporting the CSI.

[0250] Next, in step A10, the UE receives at least one CMR from the BS based on the control signal, and in A15, based on the at least one CMR, estimates at least one PMI (Precoding Matrix Index), i.e., a codeword, for at least one time instance using a Time Domain Compressed (TD) codebook. In other words, it estimates a plurality of NZCs (non-zero coefficients) that constitute the codeword. However, the maximum number of NZCs per layer is determined based on the product of the number of TD basis vectors, the number of FD basis vectors, and the number of SD basis vectors.

[0251] On the other hand, if the uplink grant resource is smaller than the payload of the CSI consisting of the estimated NZCs, the UE will drop the NZCs in order of their assigned priority value to form the CSI, as in step A20.

[0252] Specifically, the multiple NZCs have priority values ​​determined by considering, in order, the index of the TD (Time domain) basis vector, the index of the FD (Frequency domain) basis vector, the index of the SD (spatial domain) basis vector, and the layer index.

[0253] In this case, the NZCs have a higher priority value the larger the index of the TD basis vector; if the indices of the TD basis vectors are the same, the NZCs have a higher priority value the larger the index of the FD basis vector; if the indices of the TD basis vectors and the FD basis vectors are the same, the NZCs have a higher priority value the larger the index of the SD basis vector; and if the indices of the TD basis vectors, the FD basis vectors and the SD basis vectors are the same, the NZCs have a higher priority value the larger the layer index.

[0254] More specifically, the priority value (Pri(l,i,f,t)) of an NZC where the layer index is l, the index of the SD basis vector is i, the index of the FD basis vector is f, and the index of the TD basis vector is t can be determined by the above formula 2.

[0255] Finally, in stage A25, the UE transmits the CSI, which includes information about NZC, to the BS based on the uplink grant.

[0256] In the above proposal, reporting CSI for multiple time instances can mean that a single CMR set up for CSI calculation is set up in bursts for short time intervals (e.g., per slot or per symbol), or that a TD compressed codebook is set up for PMI reporting, or that one W1 and multiple W2s corresponding to other time instances are set up for PMI reporting, or that multiple time instances / multiple CSI reference resources are set up.

[0257] While the above proposal uses PMI as an example to explain a method for reducing the payload, it can be extended and applied to other CSIs outside of PMI, such as CQI.

[0258] The above proposals can finally be applied through combinations / combinations.

[0259] In the above proposal, the TD compression codebook is used as an example for explanation. However, the proposed method can also be extended and applied to the DD (Doppler domain) compression codebook.

[0260] In addition to CSI omission, the above proposal can be utilized as a method for reducing the size of the CSI payload. CSI omission can be performed when the uplink resource for reporting CSI (e.g., PUCCH resource / PUSCH resource) is set to be smaller than the CSI payload. However, regardless of the uplink resource, the proposed method can be applied for the purpose of reducing the CSI payload.

[0261] The above proposal can also be applied when an AIML UE predicts future CSI (e.g., CSI for channels after the CSI reporting time) and reports it to the base station.

[0262] Parameters mentioned in the above proposal, whether the proposal is applied or not, etc. can be set by the base station instructing the UE, the UE reporting to the base station, or as fixed values.

[0263] FIG. 17 illustrates a communication system 1 to which the present invention is applicable.

[0264] Referring to Figure 17, communication system 1 includes wireless equipment, base stations, and a network. Here, wireless equipment refers to equipment that communicates using wireless connectivity technology (e.g., 5G NR, LTE), and is also referred to as communication / wireless / 5G equipment. However, wireless equipment includes, but is not limited to, robots 100a, vehicles 100b-1, 100b-2, XR (eXtended Reality) equipment 100c, handheld devices 100d, home appliances 100e, IoT (Internet of Things) equipment 100f, and AI servers / equipment 400. For example, vehicles include vehicles equipped with wireless communication capabilities, autonomous vehicles, and vehicles capable of inter-vehicle communication. Here, vehicles include UAVs (Unmanned Aerial Vehicles) (e.g., drones). XR devices include AR (Augmented Reality) / VR (Virtual Reality) / MR (Mixed Reality) devices and are embodied in forms such as HMDs (Head-Mounted Devices), HUDs (Head-Up Displays) installed in vehicles, TVs, smartphones, computers, wearable devices, home appliances, digital signage, vehicles, and robots. Mobile devices include smartphones, smart pads, wearable devices (e.g., smartwatches, smart glasses), and computers (e.g., notebook computers). Home appliances include TVs, refrigerators, and washing machines. IoT devices include sensors and smart meters. For example, base stations and networks are also embodied in wireless devices, and certain wireless devices 200a can also operate as base stations / network nodes for other wireless devices.

[0265] Wireless devices 100a to 100f are connected to network 300 via base station 200. Artificial Intelligence (AI) technology is applied to wireless devices 100a to 100f, and wireless devices 100a to 100f are connected to AI server 400 via network 300. Network 300 is configured using a 3G network, 4G (e.g., LTE) network, or 5G (e.g., NR) network. Wireless devices 100a to 100f can communicate with each other via 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). Also, IoT devices (e.g., sensors) can communicate directly with other IoT devices (e.g., sensors) or other wireless devices 100a to 100f.

[0266] Wireless communication / connection 150a, 150b, and 150c are performed between wireless devices 100a-100f / base station 200 and between base stations 200 / base station 200. Here, wireless communication / connection is performed by uplink / downlink communication 150a and sidelink communication 150b (or D2D communication), and communication between base stations 150c (e.g., relay, IAB (Integrated Access Backhaul), etc., using various wireless connection technologies (e.g., 5G NR)). Wireless communication / connection 150a, 150b, and 150c enable wireless devices and base stations / wireless devices, and base stations to transmit / receive radio signals from each other. For example, wireless communication / connection 150a, 150b, and 150c can transmit / receive signals via various physical channels. To this end, based on various proposals of the present invention, one of the following is performed: a process of setting various configuration information for transmitting / receiving radio signals, a process of various signal processing (e.g., channel coding / decoding, modulation / demodulation, resource mapping / demapping, etc.), or a resource allocation process.

[0267] Figure 18 illustrates a wireless device to which the present invention can be applied.

[0268] Referring to Figure 18, the first wireless device 100 and the second wireless device 200 transmit and receive wireless signals using various wireless connection technologies (e.g., LTE, NR). Here, {first wireless device 100, second wireless device 200} correspond to {wireless device 100x, base station 200} and / or {wireless device 100x, wireless device 100x} in Figure 17.

[0269] 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 controls the memory 104 and / or the transceivers 106 and is configured to embody the descriptions, functions, procedures, suggestions, methods and / or flowcharts disclosed in this specification. For example, the processor 102 processes information in the memory 104 to generate first information / signals, and then transmits a wireless signal containing the first information / signals with the transceiver 106. The processor 102 also receives a wireless signal containing second information / signals with the transceiver 106, and then stores the information obtained from signal processing of the second information / signals in the memory 104. The memory 104 is linked to the processor 102 and stores various information related to the operation of the processor 102. For example, the memory 104 stores software code that includes instructions for performing some or all of the processes controlled by the processor 102, or for performing the descriptions, functions, procedures, suggestions, methods and / or flowcharts disclosed in this specification. Here, the processor 102 and memory 104 are part of a communication modem / circuit / chip designed to embody wireless communication technology (e.g., LTE, NR). The transceiver 106 is connected 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 receiver. The transceiver 106 can also be mixed with an RF (radio frequency) unit. In this invention, wireless equipment can also mean a communication modem / circuit / chip.

[0270] 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 controls the memory 204 and / or the transceivers 206 and is configured to embody the descriptions, functions, procedures, suggestions, methods and / or flowcharts disclosed in this specification. For example, the processor 202 processes information in the memory 204 to generate third information / signals, and then transmits a wireless signal containing the third information / signals with the transceiver 206. The processor 202 also receives a wireless signal containing fourth information / signals with the transceiver 206, and then stores the information obtained from signal processing of the fourth information / signals in the memory 204. The memory 204 is linked to the processor 202 and stores various information related to the operation of the processor 202. For example, the memory 204 stores software code that includes instructions for performing some or all of the processes controlled by the processor 202, or for performing the descriptions, functions, procedures, suggestions, methods and / or flowcharts disclosed in this specification. Here, the processor 202 and memory 204 are part of a communication modem / circuit / chip designed to embody wireless communication technology (e.g., LTE, NR). The transceiver 206 is connected 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 receiver. The transceiver 206 can also be mixed with an RF unit. In this invention, wireless equipment can also mean a communication modem / circuit / chip.

[0271] The hardware elements of the wireless devices 100 and 200 will be described in more detail below. However, one or more protocol layers are embodied by one or more processors 102 and 202. For example, one or more processors 102 and 202 embody one or more layers (e.g., functional layers such as PHY, MAC, RLC, PDCP, RRC, and SDAP). One or more processors 102 and 202 generate one or more PDUs (Protocol Data Units) and / or one or more SDUs (Service Data Units) by means of the descriptions, functions, procedures, suggestions, methods and / or flowcharts disclosed in this specification. One or more processors 102 and 202 generate messages, control information, data, or information by means of the descriptions, functions, procedures, suggestions, methods and / or flowcharts disclosed in this specification. One or more processors 102, 202 generate signals (e.g., baseband signals) containing PDUs, SDUs, messages, control information, data, or information by the functions, procedures, suggestions and / or methods disclosed in this specification and provide them to one or more transceivers 106, 206. One or more processors 102, 202 receive signals (e.g., baseband signals) from one or more transceivers 106, 206 and can obtain PDUs, SDUs, messages, control information, data, or information by the descriptions, functions, procedures, suggestions, methods and / or flowcharts disclosed in this specification.

[0272] One or more processors 102, 202 are also referred to as controllers, microcontrollers, microprocessors, or microcomputers. One or more processors 102, 202 are embodied by hardware, firmware, software, or a combination thereof. For example, one or more ASICs (Application Specific Integrated Circuits), one or more DSPs (Digital Signal Processors), one or more DSPDs (Digital Signal Processing Devices), one or more PLDs (Programmable Logic Devices), or one or more FPGAs (Field Programmable Gate Arrays) are included in one or more processors 102, 202. The descriptions, functions, procedures, suggestions, methods and / or flowcharts disclosed in this specification are embodied using firmware or software, and the firmware or software is embodied to include modules, procedures, functions, etc. Firmware or software configured to perform the descriptions, functions, procedures, suggestions, methods and / or flowcharts disclosed in this specification is included in one or more processors 102, 202, or is stored in one or more memories 104, 204 and driven by one or more processors 102, 202. The descriptions, functions, procedures, suggestions, methods and / or flowcharts disclosed in this specification may be embodied using firmware or software in the form of code, instructions and / or sets of instructions.

[0273] One or more memory units 104, 204 are connected to one or more processors 102, 202 and can store various forms of data, signals, messages, information, programs, code, instructions, and / or commands. One or more memory units 104, 204 consist of ROM, RAM, EPROM, flash memory, hard drives, registers, cache memory, computer read storage media, and / or combinations thereof. One or more memory units 104, 204 are located inside and / or outside one or more processors 102, 202. Furthermore, one or more memory units 104, 204 are connected to one or more processors 102, 202 by various technologies such as wired or wireless connections.

[0274] One or more transceivers 106, 206 can transmit user data, control information, radio signals / channels, etc., as referred to in the methods and / or flowcharts described herein, to one or more other devices. One or more transceivers 106, 206 can receive user data, control information, radio signals / channels, etc., as referred to in the descriptions, functions, procedures, suggestions, methods and / or flowcharts disclosed herein, from one or more other devices. For example, one or more transceivers 106, 206 can be connected to one or more processors 102, 202 to transmit and receive radio signals. For example, one or more processors 102, 202 can control one or more transceivers 106, 206 to transmit user data, control information, or radio 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 radio signals from one or more other devices. Furthermore, one or more transceivers 106, 206 are connected to one or more antennas 108, 208, and one or more transceivers 106, 206 are configured by one or more antennas 108, 208 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 in this specification. In this specification, one or more antennas are multiple physical antennas or multiple logical antennas (e.g., antenna ports). 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. 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, one or more transceivers 106, 206 include (analog) oscillators and / or filters.

[0275] Figure 19 shows another example of wireless equipment to which the present invention applies. Wireless equipment can be embodied in various forms depending on the use case / service (see Figure 17).

[0276] Referring to Figure 19, the wireless devices 100 and 200 correspond to the wireless devices 100 and 200 in Figure 18 and are composed of various elements, components, units / parts 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, 202 and / or one or more memories 104, 204 in Figure 18. For example, the transceiver 114 includes one or more transceivers 106, 206 and / or one or more antennas 108, 208 in Figure 18. The control unit 120 is electrically connected to the communication unit 110, the memory unit 130 and the additional element 140 and controls the various operations of the wireless device. For example, the control unit 120 controls the electrical and mechanical operation of the wireless device based on the program / code / 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 a wireless / wired interface using the communication unit 110, or stores information received from an external device (e.g., another communication device) via a wireless / wired interface into the memory unit 130 using the communication unit 110.

[0277] The additional element 140 is configured in various ways depending on the type of wireless device. For example, the additional element 140 includes, but is not limited to, one of the following: a power unit / battery, an input / output unit (I / O unit), a drive unit, and a computer unit. Wireless devices can be embodied in the form of robots (Figure 17, 100a), vehicles (Figure 17, 100b-1, 100b-2), XR devices (Figure 17, 100c), mobile devices (Figure 17, 100d), home appliances (Figure 17, 100e), IoT devices (Figure 17, 100f), digital broadcasting terminals, hologram devices, public safety devices, MTC devices, medical devices, fintech devices (or financial devices), security devices, climate / environmental devices, AI servers / devices (Figure 17, 400), base stations (Figure 17, 200), and network nodes. Depending on the use case / service, the wireless device may be mobile or used in a fixed location.

[0278] In Figure 19, various elements, components, units / parts and / or modules within the wireless devices 100, 200 are either entirely connected to each other by a wired interface, or at least some of them are wirelessly connected by the communication unit 110. For example, within wireless devices 100 and 200, the control unit 120 and the communication unit 110 are wired together, and the control unit 120 and the first units (e.g., 130 and 140) are wirelessly connected by the communication unit 110. Furthermore, each element, component, unit / part and / or module within wireless devices 100 and 200 further comprises one or more elements. For example, the control unit 120 is composed of one or more processor sets. For example, the control unit 120 is composed of a set of communication control processors, application processors, electronic control units (ECUs), graphics processing processors, memory control processors, etc. As another example, the memory unit 130 is composed of RAM (Random Access Memory), DRAM (Dynamic RAM), ROM (Read Only Memory), flash memory, volatile memory, non-volatile memory and / or a combination thereof.

[0279] Figure 20 illustrates a vehicle or autonomous vehicle to which the present invention applies. The vehicle or autonomous vehicle can be embodied in a mobile robot, a vehicle, a train, aerial vehicle (AV), ship, etc.

[0280] Referring to Figure 20, the 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 composed of a part of the communication unit 110. Blocks 110 / 130 / 140a to 140d correspond to blocks 110 / 130 / 140 in Figure 19, respectively.

[0281] 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 drive unit 140a enables the vehicle or autonomous vehicle 100 to travel on the ground. The drive unit 140a includes an engine, motor, powertrain, wheels, brakes, steering system, etc. The power supply unit 140b supplies power to the vehicle or autonomous vehicle 100 and includes a wired / wireless charging circuit, 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, collision sensor, wheel sensor, speed sensor, tilt sensor, weight sensor, heading sensor, position module, vehicle forward / reverse sensor, battery sensor, fuel sensor, tire sensor, steering sensor, temperature sensor, humidity sensor, ultrasonic sensor, illuminance sensor, pedal position sensor, etc. The autonomous driving unit 140d embodies technologies such as lane keeping during driving, automatic speed adjustment like adaptive cruise control, automatic driving along a predetermined route, and automatic route setting and driving when a destination is set.

[0282] As an 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 drive plan based on the obtained data. The control unit 120 controls the driving unit 140a so that the vehicle or the autonomous driving vehicle 100 moves along the autonomous driving route according to the drive plan (e.g., speed / direction adjustment). The communication unit 110 periodically obtains the latest traffic information data from the external server during autonomous driving and also obtains the traffic information data of surrounding vehicles from the surrounding vehicles. Further, the sensor unit 140c obtains the vehicle state and the surrounding environment information during autonomous driving. The autonomous driving unit 140d updates the autonomous driving route and the drive plan based on the newly obtained data / information. The communication unit 110 transmits information regarding the vehicle position, the autonomous driving route, the drive plan, etc. to the external server. The external server can predict the traffic information data in advance using AI technology, etc. based on the information collected from the vehicle or the autonomous driving vehicle and provide the predicted traffic information data to the vehicle or the autonomous driving vehicle.

[0283] The above-described embodiments are those in which the components and features of the present invention are combined in a predetermined form. Each component or feature should be considered as optional unless there is a separate explicit mention. Each component or feature can be implemented in a form not combined with other components or features. Also, it is possible to combine some components and / or features to form an embodiment of the present invention. The order of each operation described in the embodiments of the present invention can be changed. Some configurations and features of any one embodiment can be included in other embodiments or can be replaced with corresponding configurations or features of other embodiments. It is obvious that embodiments can be constituted by combining claims without an explicit citation relationship in the claims or can be included as new claims by amendment after filing.

[0284] It will be obvious to those skilled in the art that the present invention can be embodied in other specific forms without departing from the features of the invention. Therefore, the above detailed description should not be interpreted restrictively in any way, but should be considered illustrative. The scope of the invention shall be determined by a reasonable interpretation of the appended claims, and all modifications within the equivalent scope of the invention are included within the scope of the invention. [Industrial applicability]

[0285] This invention can be used in terminals, base stations, or other equipment of wireless mobile communication systems.

Claims

1. The UE (user equipment) receives DCI (downlink control information) from the BS (Base Station) to report CSI (Channel Status Information), The UE receives at least one CMR (channel measurement resource) from the BS based on the DCI, The UE calculates at least one PMI (Precoding Matrix Index) related to at least one time instance from a TD (time domain) compressed codebook based on the at least one CMR, The step includes the UE transmitting the CSI, which includes information about a plurality of non-zero coefficients (NZCs) associated with at least one PMI, based on the uplink grants included in the DCI, The method wherein the plurality of NZCs have a plurality of priority values ​​determined by sequentially considering the index of the TD basis vector, the index of the FD (Frequency Domain) basis vector, the index of the SD (Spatial Domain) basis vector, and the index of the layer.

2. The plurality of NZCs have higher priority values ​​as the index of the TD basis vector increases. Based on the fact that the indices of the TD basis vectors are the same, the plurality of NZCs have higher priority values ​​as the indices of the FD basis vectors increase. Based on the fact that the indices of the TD basis vectors are the same and the indices of the FD basis vectors are the same, the plurality of NZCs have higher priority values ​​as the indices of the SD basis vectors increase. The method according to claim 1, wherein the plurality of NZCs have higher priority values ​​as the index of the layer increases, based on the fact that the indices of the TD basis vectors are the same, the indices of the FD basis vectors are the same, and the indices of the SD basis vectors are the same.

3. The priority value for NZC is determined based on the following formula: [Formula] l is the layer index, i is the SD basis vector index, f is the FD basis vector index, and t is the TD basis vector index. υ is the number of layers, 2L is the number of SD basis vectors, and N ３ The method according to claim 1, wherein is a value related to the number of FD basis vectors, and π'(t) is a function for transforming the indices of the TD basis vectors.

4. The method according to claim 1, wherein, based on the fact that the uplink grant does not accommodate the payload of the CSI, at least one of the plurality of NZCs is dropped in order of priority value relative to the plurality of NZCs.

5. The maximum number of NZCs per layer is determined by multiplying the number of TD basis vectors, the number of FD basis vectors, the number of SD basis vectors, and a constant. The method according to claim 1, wherein the constant is greater than 0 and less than or equal to 1.

6. UE (User Equipment), At least one processor, Includes at least one computer memory that stores instructions causing the UE to perform an action when executed by the at least one processor, The aforementioned operation is, Receiving DCI (downlink control information) to report CSI (Channel Status Information) from BS (Base Station), Based on the DCI, at least one CMR (channel measurement resource) is received from the BS, Based on the aforementioned CMR, at least one PMI (Precoding Matrix Index) related to at least one time instance is calculated from the TD (time domain) compressed codebook, The CSI includes transmitting information about a plurality of non-zero coefficients (NZCs) associated with at least one PMI, based on the uplink grant included in the DCI, The aforementioned NZCs have a plurality of priority values ​​determined by sequentially considering the index of the TD basis vector, the index of the FD (Frequency Domain) basis vector, the index of the SD (Spatial Domain) basis vector, and the index of the layer, respectively, as UE.

7. The plurality of NZCs have higher priority values ​​as the index of the TD basis vector increases. Based on the fact that the indices of the TD basis vectors are the same, the plurality of NZCs have higher priority values ​​as the indices of the FD basis vectors increase. Based on the fact that the indices of the TD basis vectors are the same and the indices of the FD basis vectors are the same, the plurality of NZCs have higher priority values ​​as the indices of the SD basis vectors increase. The UE according to claim 6, wherein the plurality of NZCs have higher priority values ​​as the index of the layer increases, based on the fact that the indices of the TD basis vectors are the same, the indices of the FD basis vectors are the same, and the indices of the SD basis vectors are the same.

8. The priority value for NZC is determined based on the following formula: [Mathematical formula] l is the layer index, i is the SD basis vector index, f is the FD basis vector index, and t is the TD basis vector index. υ is the number of layers, 2L is the number of SD basis vectors, and N ３ The UE according to claim 6, wherein is a value related to the number of FD basis vectors, and π'(t) is a function for transforming the indices of the TD basis vectors.

9. The UE according to claim 6, wherein, based on the uplink grant not accommodating the payload of the CSI, at least one of the plurality of NZCs is dropped in order of priority value relative to the plurality of NZCs.

10. The maximum number of NZCs per layer is determined by multiplying the number of TD basis vectors, the number of FD basis vectors, the number of SD basis vectors, and a constant. The UE according to claim 6, wherein the constant is greater than 0 and less than or equal to 1.

11. A non-temporary computer-readable storage medium containing program instructions, When the aforementioned program instruction is executed by at least one processor, it causes the UE (User Equipment) to perform an action. The aforementioned operation is, Receiving DCI (downlink control information) to report CSI (Channel Status Information) from BS (Base Station), Based on the DCI, at least one CMR (channel measurement resource) is received from the BS, Based on the aforementioned CMR, at least one PMI (Precoding Matrix Index) related to at least one time instance is calculated from the TD (time domain) compressed codebook, The CSI includes transmitting information about a plurality of non-zero coefficients (NZCs) associated with at least one PMI, based on the uplink grant included in the DCI, The aforementioned NZCs have a plurality of priority values ​​determined by sequentially considering the index of the TD basis vector, the index of the FD (Frequency Domain) basis vector, the index of the SD (Spatial Domain) basis vector, and the index of the layer, respectively, as storage media.

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