Scalar quantization-based channel state information feedback mechanism

Abstract

According to one aspect of the present disclosure, a method is provided, in an apparatus, the method comprising the steps of: obtaining a quantized channel estimate for at least a subset of channel estimates by quantizing the channel estimate using scalar quantization, wherein the channel estimate is obtained for channel state information reference symbols (CSI-RS) transmitted across a plurality of transmission antenna ports; and transmitting channel state information (CSI) based on the quantized channel estimate.

Description

[Technical Field]

[0001] Cross-reference of related applications This disclosure claims priority and interest in U.S. Provisional Application No. 63 / 453,007, filed with the U.S. Patent and Trademark Office on 17 March 2023.

[0002] This application relates generally to wireless telecommunications, and more specifically to a system and method for transmitting and receiving channel status information (CSI), as well as a method for configuring the transmission of CSI. [Background technology]

[0003] According to the new Radio (NR) standard, the CSI feedback mechanism has been modified on several occasions in subsequent releases. For example, R15 specifies Type I / II codebooks, R16 specifies Type II tf compression, R17 specifies reciprocity-based codebooks, and R18 specifies codebooks specifically designed for mobility.

[0004] This is a significant standardization effort with each release, including new chipset implementation efforts for each codebook extension.

[0005] 6G networks have a diverse set of implementation scenarios, including a variety of frequency bands, transceiver architectures such as hybrid beamforming (HBF) and / or digital beamforming (DBF), and multiple antenna array options such as uniform or heterogeneous antenna arrays, and two-dimensional or three-dimensional antenna arrays.

[0006] For example, the carrier frequency range may include less than 3 GHz, C band, 6-15 GHz (cm wave), mm wave, and less than THz. The transceiver architecture in gNB is: For frequencies below 3GHz, fully digital RF is also acceptable. For the C band, 6-15 GHz, a fully digital RF system may be used for horizontal antenna elements, and a hybrid (analog + digital RF) system may be used for vertical antenna elements. For mm waves and frequencies below THz, HBF may also be used. The antenna array may be, for example, a uniform or non-uniform antenna panel, or a two-dimensional or three-dimensional antenna aperture.

[0007] The number of antenna ports may be 2^n for some value of n, or there may be a more general constraint that the number of antenna ports N is less than or equal to some number M of supported antenna ports.

[0008] CSI transmission can be performed in these diverse situations and in a variety of scenarios, including CSI for various narrowband vs. wideband and high-speed / medium-speed / low-speed equipment (UE). [Overview of the Initiative] [Means for solving the problem]

[0009] According to one aspect of the present disclosure, a method is provided comprising the steps of: obtaining a quantized channel estimate for at least a subset of channel estimates by quantizing the channel estimate using scalar quantization, wherein the channel estimate is obtained for channel state information reference symbols (CSI-RS) transmitted across a plurality of transmission antenna ports; and transmitting channel state information (CSI) based on the quantized channel estimate.

[0010] In some embodiments, the method further includes the step of performing compression of quantized channel estimates to generate compressed quantized channel estimates, and the step of transmitting channel state information (CSI) based on quantized channel estimates further includes the step of transmitting compressed quantized channel estimates.

[0011] In some embodiments, the method further includes receiving first signaling, and when the first signaling indicates to perform scalar quantization on channel estimation values, obtaining respective quantized channel estimation values by quantizing the channel estimation values using scalar quantization for at least each subset of the channel estimation values, and performing the steps of transmitting channel state information (CSI) based on the quantized channel estimation values.

[0012] In some embodiments, the method further includes receiving second signaling, and when the second signaling indicates to use vector quantization on channel estimation values, transmitting CSI feedback using vector quantization.

[0013] In some embodiments, the method further includes receiving signaling indicating quantization accuracy applied to all channel estimation values, and performing quantization using the indicated quantization accuracy.

[0014] In some embodiments, the method further includes receiving signaling indicating respective quantization accuracies applied to respective channel estimation values, and performing quantization of the respective channel estimation values using the respective quantization accuracies.

[0015] In some embodiments, each quantization accuracy includes an indication of a first number of bits for amplitude and an indication of a second number for phase.

[0016] In some embodiments, the method further includes selecting a subset of channel estimation values to be fed back, and transmitting an indication of the selected subset of channel estimation values that are being fed back.

[0017] In some embodiments, the step of selecting a subset of channel estimates to be fed back includes the step of applying a threshold based on the strongest channel estimate.

[0018] In some embodiments, the at least subset of channel estimates includes all of the channel estimates.

[0019] In some embodiments, the method further includes the step of receiving signaling indicating the configuration of the transmitted CSI-RS.

[0020] According to one aspect of the present disclosure, an apparatus is provided comprising a processor and a computer-readable storage medium storing computer-executable instructions. When executed by the processor, the computer-executable instructions cause the apparatus to obtain a quantized channel estimate for at least a subset of channel estimates by quantizing the channel estimates using scalar quantization, the channel estimates being obtained for CSI-RS transmitted across a plurality of transmission antenna ports, and the CSI being transmitted based on the quantized channel estimates.

[0021] In some embodiments, the computer executable instruction further includes, when executed by the processor, a computer executable instruction that causes the device to perform the method described above.

[0022] According to one aspect of the present disclosure, a method is provided comprising the step of receiving channel state information (CSI), the CSI being transmitted based on quantized channel estimates, and for at least a subset of channel estimates, each quantized channel estimate being obtained by quantizing the channel estimate using scalar quantization, and the channel estimates being obtained for a CSI reference symbol (CSI-RS) transmitted across a plurality of transmission antenna ports.

[0023] According to one aspect of the present disclosure, a non-temporary computer-readable storage medium is provided, the computer-readable storage medium storing instructions that, when executed by the processor of the device, enable the device to perform the method described above.

[0024] Next, embodiments of the present disclosure will be described with reference to the attached drawings. [Brief explanation of the drawing]

[0025] [Figure 1] This is a block diagram of a communication system. [Figure 2] This is a block diagram of a communication system. [Figure 3] This is a block diagram of a communication system showing the basic component structure of electronic devices (EDs) and base stations. [Figure 4] This is a block diagram of a module that may be used to carry out or perform one or more steps of the embodiments of this application. [Figure 5A] This document outlines a framework for CSI reporting. [Figure 5B] This shows a UE function block for CSI reporting using scalar quantization. [Figure 6A] An example of sparse CSI-RS is shown. [Figure 6B] An example of sparse CSI-RS is shown. [Figure 7] This is a flowchart of the CSI-RS reporting method. [Figure 8] This is a detailed example of channel estimation. [Figure 9] The set of quantized channel estimates generated from the example in Figure 8 is shown. [Figure 10] Examples of spatial, frequency, and time domains that may be used in CSI-RS transmissions to which vector quantization may be applied, according to embodiments of this disclosure. [Figure 11] An example of a uniform planar antenna array that may be used for transmitting a reference signal of a CSI being processed, according to an embodiment of this application, is shown. [Figure 12] An example of a three-dimensional antenna array that may be used for transmitting a reference signal of a CSI being processed, according to an embodiment of this application, is shown. [Figure 13] An example of a chirp signal that can be used as a reference signal for determining CSI according to an embodiment of this application is shown. [Figure 14] An example of a chirp beam basis matrix for a UE in a near-field antenna according to an embodiment of this application is shown. [Figure 15] An example of a basis matrix shown to constitute a subset of the basis matrix according to the embodiments of this application is provided. [Figure 16] An example of an equation for determining a basis matrix using oversampling according to an embodiment of this application is shown. [Figure 17] This document outlines a framework for CSI reporting. [Figure 18] This is a signal flow diagram for signaling between a UE and a base station (BS) according to embodiments of the present disclosure. [Figure 19] This is an example of a coordinate transformation. [Modes for carrying out the invention]

[0026] Embodiments of this disclosure provide a unified, configurable CSI feedback mechanism suitable, for example, 6G MIMO. The novel CSI feedback mechanism includes a feedback mechanism based on scalar quantization.

[0027] Referring to Figure 1, a simplified schematic diagram of a communication system is provided as an illustrative, not limiting, example. The communication system 100 comprises a radio access network 120. The radio access network 120 may be a next-generation (e.g., 6G or later) radio access network or a legacy (e.g., 5G, 4G, 3G, or 2G) radio access network. One or more communication electrical devices (EDs) 110a-120j (collectively referred to as 110) may be interconnected with each other or connected to one or more network nodes (170a, 170b, collectively referred to as 170) within the radio access network 120. The core network 130 may be part of the communication system and may or may not depend on the radio access technology used in the communication system 100. The communication system 100 also comprises a public switched telephone network (PSTN) 140, the Internet 150, and other networks 160.

[0028] Figure 2 shows an exemplary communication system 100. Generally, the communication system 100 enables multiple wireless or wired elements to communicate data and other content. The purpose of the communication system 100 may be to provide content such as voice, data, video, and / or text via broadcast, multicast, and unicast, etc. The communication system 100 may operate by sharing resources such as carrier spectral bandwidth among its components. The communication system 100 may include a terrestrial communication system and / or a non-terrestrial communication system. The communication system 100 may provide a wide range of communication services and applications, such as earth monitoring, remote sensing, passive sensing and positioning, navigation and tracking, autonomous delivery and mobility, etc. The communication system 100 may provide high availability and robustness through the joint operation of the terrestrial and non-terrestrial communication systems. For example, integrating a non-terrestrial communication system (or its components) into a terrestrial communication system can result in what can be thought of as a heterogeneous network with multiple layers. Compared to conventional communication networks, heterogeneous networks can achieve better overall performance through efficient multilink collaboration between terrestrial and non-terrestrial networks, more flexible function sharing, and faster physical layer link switching.

[0029] Terrestrial and non-terrestrial communication systems can be considered subsystems of a communication system. In the illustrated example, communication system 100 includes electronic devices (EDs) 110a-110d (collectively referred to as ED110), radio access networks (RANs) 120a-120b, non-terrestrial communication networks 120c, core network 130, public switched telephone network (PSTN) 140, the internet 150, and other networks 160. RANs 120a-120b include their respective base stations (BS, e.g., gNBs) 170a-170b, which may be collectively referred to as terrestrial transceiver points (T-TRPs) 170a-170b. Non-terrestrial communication networks 120c include access nodes 120c, which may be collectively referred to as non-terrestrial transceiver points (NT-TRPs) 172.

[0030] Any ED110 may be configured to interface with, access, or communicate with any other T-TRP170a-170b and NT-TRP172, the Internet 150, the core network 130, the PSTN 140, other networks 160, or any combination thereof. In some examples, ED110a may communicate with T-TRP170a for uplink and / or downlink transmissions via interface 190a. In some examples, ED110a, 110b, and 110d may also communicate directly with each other via one or more sidelink air interfaces 190b. In some examples, ED110d may communicate with NT-TRP172 for uplink and / or downlink transmissions via interface 190c.

[0031] Air interfaces 190a and 190b may use any suitable radio access technology or similar communication technology. For example, communication system 100 may implement one or more channel access methods in air interfaces 190a and 190b, such as code division multiple access (CDMA), time division multiple access (TDMA), frequency division multiple access (FDMA), orthogonal FDMA (OFDMA), or single-carrier FDMA (SC-FDMA). Air interfaces 190a and 190b may utilize other higher-dimensional signal spaces, which may include combinations of orthogonal and / or non-orthogonal dimensions.

[0032] The air interface 190c can enable communication between the ED110d and one or more NT-TRP172s via a wireless link or simply a link. In some examples, the link is a dedicated connection for unicast transmission, a connection for broadcast transmission, or a connection between a group of EDs and one or more NT-TRPs for multicast transmission.

[0033] RAN120a and 120b communicate with the core network 130 to provide various services to ED110a, 110b, and 110c, such as voice, data, and other services. RAN120a and 120b and / or the core network 130 may communicate directly or indirectly with one or more other RANs (not shown) that may or may not be directly serviced by the core network 130 and may or may not use the same radio access technology as RAN120a, RAN120b, or both. The core network 130 may also function as a gateway access between (i) RAN120a and 120b or ED110a, 110b, and 110c or both, and (ii) other networks (such as PSTN 140, the Internet 150, and other networks 160). In addition, some or all of ED110a, 110b, and 110c may include the ability to communicate with different wireless networks via different wireless links using different wireless technologies and / or protocols. Instead of (or in addition to) wireless communication, ED110a, 110b, and 110c may communicate with a service provider or switch (not shown) and the Internet 150 via a wired communication channel. PSTN 140 may include a circuit-switched telephone network for providing conventional telephone services (POTS). The Internet 150 may include a network and subnet (intranet) of computers or both, and may incorporate protocols such as Internet Protocol (IP), Transmission Control Protocol (TCP), and User Datagram Protocol (UDP). ED110a, 110b, and 110c may be multimode devices capable of operating according to multiple wireless access technologies and may incorporate multiple transceivers as necessary to support such operation.

[0034] Figure 3 shows another example of the ED110 and base stations 170a, 170b, and / or 170c. The ED110 is used to connect people, things, machines, etc. The ED110 can be widely used in various scenarios, such as cellular communication, device-to-device (D2D), vehicle-to-vehicle / vehicle-to-infrastructure (V2X), peer-to-peer (P2P), machine-to-machine (M2M), machine-type communication (MTC), Internet of Things (IoT), virtual reality (VR), augmented reality (AR), industrial control, autonomous driving, telemedicine, smart grids, smart furniture, smart offices, smart wearables, smart transportation, smart cities, drones, robots, remote sensing, passive sensing, positioning, navigation and tracking, autonomous delivery and mobility, etc.

[0035] Each ED110 represents any end-user device suitable for wireless operation, and among other possibilities, may include user equipment / devices (UE), wireless transmission / receiving units (WTRU), mobile stations, fixed or mobile subscriber units, cellular telephones, stations (STA), machine-type communications (MTC) devices, personal digital assistants (PDAs), smartphones, laptops, computers, tablets, wireless sensors, consumer electronics devices, smartbooks, vehicles, automobiles, trucks, buses, trains, or IoT devices, industrial devices, or devices within the aforementioned devices (e.g., communication modules, modems, or chips). Future generations of ED110 may be referred to using other terms. Base stations 170a and 170b are T-TRPs and will be referred to as T-TRP170 below. As also shown in Figure 3, the NT-TRP will be referred to as NT-TRP172 below. Each ED110 connected to the T-TRP170 and / or NT-TRP172 can be dynamically or semi-statically turned on (i.e., established, activated, or enabled), turned off (i.e., released, deactivated, or disabled), and / or configured in response to one of several factors, connection availability and connection need.

[0036] ED110 includes a transmitter 201 and a receiver 203 coupled to one or more antennas 204. Only one antenna 204 is shown. One, some, or all of the antennas may be a panel. The transmitter 201 and receiver 203 may be integrated as, for example, a transceiver. The transceiver is configured to modulate data or other content for transmission by at least one antenna 204 or a network interface controller (NIC). The transceiver is also configured to demodulate data or other content received by at least one antenna 204. Each transceiver includes any suitable structure for generating signals for wireless or wired transmission and / or processing signals received wirelessly or wired. Each antenna 204 includes any suitable structure for transmitting and / or receiving wireless or wired signals.

[0037] In addition, the ED110 includes at least one memory 208. The memory 208 stores instructions and data used, generated, or collected by the ED110. For example, the memory 208 can store software instructions or modules executed by the processing unit 210, configured to perform some or all of the functions and / or embodiments described herein. Each memory 208 includes any suitable volatile and / or non-volatile storage and retrieval device. Any suitable type of memory may be used, such as random access memory (RAM), read-only memory (ROM), hard disk, optical disk, subscriber identification module (SIM) card, memory stick, secure digital (SD) memory card, and on-processor cache.

[0038] The ED110 may further include one or more input / output devices (not shown) or interfaces (such as a wired interface to the Internet 150 in Figure 1). The input / output devices enable interaction with the user or other devices in the network. Each input / output device includes any suitable structure for providing information to or receiving information from the user, including network interface communication, such as a speaker, microphone, keypad, keyboard, display, or touchscreen.

[0039] ED110 further includes a processor 210 for performing operations related to preparing transmissions for uplink transmissions to NT-TRP172 and / or T-TRP170, processing downlink transmissions received from NT-TRP172 and / or T-TRP170, and processing sidelink transmissions to and from another ED110. Processing operations related to preparing transmissions for uplink transmissions may include operations such as encoding, modulating, transmission beamforming, and generating symbols for transmission. Processing operations related to processing downlink transmissions may include operations such as receiving beamforming, demodulation, and decoding of received symbols. Depending on the embodiment, the downlink transmission may be received by a receiver 203, possibly using receive beamforming, and the processor 210 may extract signaling from the downlink transmission (e.g., by detecting and / or decoding the signaling). An example of signaling may be a reference signal transmitted by NT-TRP172 and / or T-TRP170. In some embodiments, the processor 276 performs transmission beamforming and / or reception beamforming based on beam direction indications, such as beam angle information (BAI), received from the T-TRP 170. In some embodiments, the processor 210 may perform operations related to network access (e.g., initial access) and / or downlink synchronization, such as operations related to synchronization sequence detection, decoding and retrieval of system information. In some embodiments, the processor 210 may perform channel estimation using, for example, reference signals received from the NT-TRP 172 and / or the T-TRP 170.

[0040] Although not shown, the processor 210 may form part of the transmitter 201 and / or receiver 203. Although not shown, the memory 208 may form part of the processor 210.

[0041] The processing components of the processor 210 and the transmitter 201 and receiver 203 may each be implemented by one or more identical or different processors configured to execute instructions stored in memory (e.g., memory 208). Alternatively, some or all of the processing components of the processor 210 and the transmitter 201 and receiver 203 may be implemented using dedicated circuits such as programmed field-programmable gate arrays (FPGAs), graphics processing units (GPUs), or application-specific integrated circuits (ASICs).

[0042] In some embodiments, T-TRP170 may be known by other names, among other possibilities, such as base station, base transceiver station (BTS), radio base station, network node, network device, network-side device, transmission / receiving node, node B, advanced node B (enode B or eNB), home enode B, next-generation node B (gNB), transmission point (TP), site controller, access point (AP), or wireless router, relay station, remote radio head, ground node, ground network device, or ground base station, baseband unit (BBU), remote radio unit (RRU), active antenna unit (AAU), remote radio head (RRH), central unit (CU), distributed unit (DU), positioning node, etc. T-TRP170 may also be a macro BS, pico BS, relay node, or donor node, or a combination thereof. T-TRP170 may refer to a forged device or a device within the aforementioned device (e.g., a communication module, modem, or chip).

[0043] In some embodiments, portions of the T-TRP170 may be distributed. For example, some modules of the T-TRP170 may be located away from the equipment housing the T-TRP170 antenna and may be coupled to the equipment housing the antenna via a communication link (not shown) sometimes known as a fronthaul, such as a Common Public Radio Interface (CPRI). Thus, in some embodiments, the term T-TRP170 may also refer to network-side modules that are not necessarily part of the equipment housing the T-TRP170 antenna and perform processing operations such as determining the location of the ED110, resource allocation (scheduling), message generation, and coding / decoding. These modules may also be coupled to other T-TRPs. In some embodiments, the T-TRP170 may actually be multiple T-TRPs working together to service the ED110, for example, by coordinated multipoint transmission.

[0044] The T-TRP170 includes at least one transmitter 252 and at least one receiver 254 coupled to one or more antennas 256. Only one antenna 256 is shown. One, some, or all of the antennas, or a panel, may be present. The transmitter 252 and receiver 254 may be integrated as a transceiver. The T-TRP170 further includes a processor 260 for performing operations including operations related to preparing transmission for downlink transmission to ED110, processing uplink transmission received from ED110, preparing transmission for backhaul transmission to NT-TRP172, and processing transmission received from NT-TRP172 via backhaul. Processing operations related to preparing transmission for downlink or backhaul transmission may include operations such as encoding, modulation, precoding (e.g., MIMO precoding), transmission beamforming, and generation of symbols for transmission. Processing operations related to processing received transmission in uplink or backhaul may include operations such as receive beamforming, demodulation, and decoding of received symbols. The processor 260 may also perform operations related to network access (e.g., initial access) and / or downlink synchronization, such as generating the content of synchronous signal blocks (SSBs) and generating system information. In some embodiments, the processor 260 may also generate beam direction instructions, e.g., BAI, which can be scheduled for transmission by the scheduler 253. The processor 260 performs other network-side processing operations described herein, such as determining the location of the ED 110 and determining where to deploy the NT-TRP 172. In some embodiments, the processor 260 may generate signaling to configure, for example, one or more parameters of the ED 110 and / or one or more parameters of the NT-TRP 172. The signaling generated by the processor 260 is transmitted by the transmitter 252. Note that, as used herein, “signaling” may also be called control signaling.Dynamic signaling may be transmitted over a control channel, such as a physical downlink control channel (PDCCH), while static or semi-static upper-layer signaling may be included in packets transmitted over a data channel, such as a physical downlink shared channel (PDSCH).

[0045] The scheduler 253 may be coupled to the processor 260. The scheduler 253 may be contained within the T-TRP 170 or may operate separately, and may schedule uplink, downlink, and / or backhaul transmissions, including issuing scheduling grants and / or configuring scheduling-free ("configuration grants") resources. The T-TRP 170 further includes memory 258 for storing information and data. Memory 258 stores instructions and data used, generated, or collected by the T-TRP 170. For example, memory 258 may store software instructions or modules executed by the processor 260, configured to perform some or all of the functions and / or embodiments described herein.

[0046] Although not shown, the processor 260 may form part of the transmitter 252 and / or receiver 254. Also, although not shown, the processor 260 may perform the function of a scheduler 253. Although not shown, memory 258 may form part of the processor 260.

[0047] The processing components of processor 260, scheduler 253, and transmitter 252 and receiver 254 may each be implemented by one or more identical or different processors configured to execute instructions stored in memory (e.g., memory 258). Alternatively, some or all of the processing components of processor 260, scheduler 253, and transmitter 252 and receiver 254 may be implemented using dedicated circuitry such as FPGAs, GPUs, or ASICs.

[0048] Although NT-TRP172 is shown only as a drone as an example, NT-TRP172 may be implemented in any suitable non-terrestrial form. NT-TRP172 may also be known by other names in some embodiments, such as a non-terrestrial node, a non-terrestrial network device, or a non-terrestrial base station. NT-TRP172 includes a transmitter 272 and a receiver 274 coupled to one or more antennas 280. Only one antenna 280 is shown. One, some, or all of the antennas may be a panel. The transmitter 272 and receiver 274 may be integrated as a transceiver. NT-TRP172 further includes a processor 276 for performing operations including operations related to preparing transmissions for downlink transmissions to ED110, processing uplink transmissions received from ED110, preparing transmissions for backhaul transmissions to T-TRP170, and processing transmissions received from T-TRP170 via backhaul. Processing operations related to preparing transmissions for downlink or backhaul transmissions may include operations such as encoding, modulation, precoding (e.g., MIMO precoding), transmission beamforming, and generation of symbols for transmission. Processing operations related to processing received transmissions in uplink or backhaul may include operations such as receive beamforming, demodulation, and decoding of received symbols. In some embodiments, the processor 276 performs transmission beamforming and / or receive beamforming based on beam direction information (e.g., BAI) received from the T-TRP 170. In some embodiments, the processor 276 may generate signaling to configure one or more parameters of, for example, the ED 110. In some embodiments, the NT-TRP 172 performs physical layer processing but does not perform higher layer functions such as functions in the media access control (MAC) or radio link control (RLC) layer. This is just an example, and more generally, the NT-TRP 172 may perform higher layer functions in addition to physical layer processing.

[0049] The NT-TRP172 further includes a memory 278 for storing information and data. Although not shown, a processor 276 may form part of the transmitter 272 and / or receiver 274. Although not shown, the memory 278 may form part of the processor 276.

[0050] The processing components of processor 276 and transmitter 272 and receiver 274 may each be implemented by one or more identical or different processors configured to execute instructions stored in memory, for example, memory 278. Alternatively, some or all of the processing components of processor 276 and transmitter 272 and receiver 274 may be implemented using dedicated circuitry such as a programmed FPGA, GPU, or ASIC. In some embodiments, NT-TRP 172 may actually be multiple NT-TRPs working together to service ED110, for example by cooperative multipoint transmission.

[0051] T-TRP170, NT-TRP172, and / or ED110 may include other components, but these are omitted for clarity.

[0052] One or more steps of the methods of the embodiments provided herein may be performed by corresponding units or modules, as shown in Figure 4. Figure 4 shows units or modules in a device such as ED110, T-TRP170, or NT-TRP172. For example, a signal may be transmitted by a transmission unit or transmission module. For example, a signal may be transmitted by a transmission unit or transmission module. A signal may be received by a receiving unit or receiving module. A signal may be processed by a processing unit or processing module. Other steps may be performed by artificial intelligence (AI) or machine learning (ML) modules. Each unit or module may be implemented using hardware, one or more components or devices that run software, or a combination thereof. For example, one or more of the units or modules may be integrated circuits such as programmed FPGAs, GPUs, or ASICs. If the modules are implemented using software for execution by a processor, it will be acknowledged that, for example, they may be retrieved by the processor in one or more instances, individually or together, as whole or in part, for processing, and that the modules themselves may contain instructions for further deployment and instantiation.

[0053] Further details regarding ED110, T-TRP170, and NT-TRP172 are known to those skilled in the art; therefore, these details are omitted here.

[0054] The overall CSI feedback framework is shown in Figure 5A. This framework can be implemented, for example, using the systems shown in Figures 1 to 4. CSI-RS transmission is generally shown in 500. CSI feedback configuration is generally shown in 502. The gNB implements 500 and 502. UE-side functions include CSI measurements, generally shown in 504, and CSI reporting, generally shown in 506. CSI-RS Transmission

[0055] CSI-RS is transmitted using a transmission antenna port. Transmission using an antenna port involves transmitting known reference symbols using one or more designated antennas and one or more OFDM subcarriers. CSI configuration

[0056] The CSI configuration includes the transmission of signaling from the gNB to the UE to inform the UE of the nature of the CSI-RS transmission (e.g., CSI RS port configuration) and / or how to report the CSI. In some embodiments, multiple feedback mechanisms are available for use by the UE, one of which is a method of providing feedback based on scalar quantization. In some embodiments, the CSI configuration includes the gNB transmitting instructions on which feedback mechanism to use, among the scalar quantization-based method and one or more other methods. Application scenarios for the use of scalar quantization-based feedback include, but are not limited to, detection-assisted channel acquisition and AI-assisted channel acquisition. CSI measurement

[0057] CSI measurement in a UE, also known as channel estimation, involves estimating the CSI (e.g., amplitude and phase) for each receiving antenna and each transmitting antenna port. The full set of channel estimates includes one estimate for each transmitting antenna port and each receiving antenna pair. The UE performs CSI estimation on the configured CSI-RS resources to obtain channel estimates between the gNB and the UE. CSI report

[0058] CSI reporting, also known as CSI feedback, involves the transmission of information from the UE to the gNB based on CSI estimates. In some embodiments, multiple feedback mechanisms are available for use by the UE, one of which is a method of providing feedback based on scalar quantization. In some embodiments, the gNB transmits instructions on which feedback mechanism to use, among the provided method based on scalar quantization and one or more other methods. Another available mechanism may be, for example, one of the existing codebook-based mechanisms. Which feedback mechanism a given UE uses may be determined based on explicit or implicit signaling from the base station, or it may be determined based on other conditions. For example, in one embodiment, the UE: Transparency of the antenna structure to the UE (meaning whether the UE is aware of the antenna deployment scenario), Sparsity of RS transmission (for example, in the case of supersparse reference symbol (RS) transmission, when the sparsity is sufficiently sparse (e.g., defined by some metric and associated threshold), feedback based on scalar quantization can be used; Figure 6A shows an example of sparse CSI-RS transmission, where it can be understood that CSI-RS is transmitted in only a fraction of the possible locations in the frequency transmission antenna dimension; Figure 6B shows another example, where the RS is beamformed, for example, in the case of beamformed RS, scalar quantization is used), UE capability (Since feedback based on scalar quantization can be relatively low in complexity compared to other mechanisms, it may be suitable for UEs with low ability to use such mechanisms.) Based on one or more of these factors, you select which feedback method to use. For example, a codebook-based method may involve the use of computationally intensive matrix operations, such as matrix factorization and matrix multiplication, which are not required for a scalar quantization-based method.

[0059] In the scalar quantization-based approach, the set of channel estimates itself (after quantization, and possibly compression) is fed back. This is relatively simpler compared to codebook-based methods where the channel estimate vectors are projected onto a codebook matrix and then quantized. This approach is particularly well-suited to CSI feedback measured in discontinuous blocks, for example, based on a hypersparse reference signal in the time / frequency / space domain.

[0060] An example of the UE function is shown in Figure 5B. Channel estimation block 510 and quantization block 512 are shown. Quantization block 512 performs scalar quantization according to the method described herein. CSI reporting is performed based on the output of scalar quantization. Methods for CSI reporting using scalar quantization

[0061] In this embodiment, the UE directly quantizes the complex numbers of the CSI-RS channel estimates and then feeds some or all of these quantized values ​​back to the gNB. Optionally, the quantized data is also compressed based on a configured compression scheme, and the compressed quantized values ​​are fed back to the gNB. The compression scheme includes transforms, entropy coding, etc. The transform may be a Fast Fourier Transform (FFT), Inverse Fast Fourier Transform (IFFT), Discrete Cosine Transform (DCT), or Wavelet Transform. The entropy coding may include arithmetic coding, Huffman coding, or Run-Length coding.

[0062] In some embodiments, each channel estimate has its own index. The index of a given channel estimate is associated with the receiving antenna and transmitting antenna ports. In some embodiments, all channel estimates are fed back. In some embodiments, only a subset of channel estimates are fed back, and to indicate which channel estimates are being fed back, the UE also transmits a set of indices to the gNB to identify them. Specific examples of which channel estimates to be fed back are selected based on relative channel strength are described below.

[0063] In embodiments that include compression, an order may be specified for aggregating channel estimates in order to perform compression.

[0064] The quantization precision of the channel estimate for CSI feedback can be configured in the signaling from the gNB. This can, for example, configure the number of bits for quantizing the estimate by the UE. Alternatively, the quantization precision can be associated with the number of configured RS resources.

[0065] In some embodiments, all channel estimates are quantized with a common quantization precision. Alternatively, the quantization precision can differ for different channel estimates. For example, higher precision may be used for critical estimates. In some embodiments, differential quantization of channel estimates is used. In some embodiments, the quantization precision is specified separately for amplitude and phase. For example, (3,4) bits may mean quantization using 3 bits for amplitude and 4 bits for phase.

[0066] In some embodiments, criteria such as thresholds are used to select which channel estimates to feed back. In a particular example, given channel estimate C i The channel estimate is fed back if the following is true:

number

[0067] A specific example of UE behavior is shown in the flowchart in Figure 7. At 700, the UE performs channel estimation based on the RS configuration. At 702, the UE selects the channel estimate to feed back based on the configured threshold. At 704, the UE performs quantization of the selected channel estimate. At 706, the UE transmits the quantized channel estimate to the gNB. The UE also transmits the index of the selected channel estimate. These can be transmitted together with the channel estimate or separately.

[0068] In some embodiments, the UE transmits a capability report indicating the number of transmission antenna ports. The indicated number of antenna ports serves as a threshold for the base station to determine whether to instruct the UE to use the scalar quantization method or a more complex method provided by channel feedback. This technique is suitable for situations where the UE may not have the computational power to perform the more complex method for a larger number of antennas, for example, when it cannot perform matrix calculations exceeding a certain size. For example, the UE may transmit a capability report indicating a transmission antenna port capability of 16. A gNB with 128 antenna ports > 16 then configures the UE to use the scalar quantization method.

[0069] Detailed examples are shown in Figures 8 and 9. Figure 8 shows a set of channel estimates for the sparse pattern in Figure 6A. To select the channel estimates to feed back, the sequence is normalized to the maximum amplitude value. In the illustrated example, the maximum amplitude = 180.77986620472976. The normalized sequence is as follows:

[0070] The normalized amplitudes are 0.25392, 0.32416, 0.27448, 0.065109, 0.1374, 0.21382, 1, 0.21846, 0.19411, and 0.19956.

[0071] Quantization is performed on the amplitude using 4 bits: 0.281250, 0.343750, 0.281250, 0.093750, 0.156250, 0.218750, 0.968750, 0.218750, 0.218750, 0.218750.

[0072] Transfer them to bits: 0100, 0101, 0100, 0010, 0011, 0100, 1111, 0100, 0100, 0100.

[0073] Perform Huffman coding to compress the data to 1011101011111110001101000.

[0074] The normalized phases are 0.79697, 0.4381, 0.38515, -2.7148, 0.9367, 0.6715, -2.157, 0.1351, 0.30761, and 1.0808.

[0075] Perform quantization on the amplitude with 5 bits: 11111001011011101001100010001.

[0076] In this particular example, 4-bit quantization is performed on the amplitude and 5-bit quantization is performed on the phase. The quantized values ​​are shown in Figure 9. In embodiments where not all channel estimates are fed back, selection criteria (e.g., the relative amplitude criterion described above) are applied to select which channel estimates to feed back. The quantized versions of the selected channel estimates are then fed back along with their indices. In the example above, where there are 10 channel estimates, these can be given indices from 0 to 9.

[0077] The overall CSI feedback framework is shown in Figure 17. This framework can be implemented, for example, using the systems shown in Figures 1 to 4. CSI-RS transmission is generally shown in 1700. CSI feedback configuration is generally shown in 1702. The gNB implements 1700 and 1702. UE-side functions include CSI measurements, generally shown in 1704, and CSI reporting, generally shown in 1706. CSI-RS Transmission

[0078] CSI-RS is transmitted using a transmission antenna port. Transmission using an antenna port involves transmitting known reference symbols using one or more designated antennas and one or more OFDM subcarriers. CSI configuration

[0079] The CSI configuration includes the transmission of signaling from the gNB to the UE to inform the UE of the nature of the CSI-RS transmission (e.g., CSI RS port configuration) and / or how to report the CSI. In some embodiments, multiple feedback mechanisms are available for use by the UE, one of which is a method of providing feedback based on scalar quantization. In some embodiments, the CSI configuration includes the gNB transmitting instructions on which feedback mechanism to use, among the scalar quantization-based method and one or more other methods. Application scenarios for the use of scalar quantization-based feedback include, but are not limited to, detection-assisted channel acquisition and artificial intelligence (AI)-assisted channel acquisition. CSI measurement

[0080] CSI measurement in a UE, also known as channel estimation, involves estimating the CSI (e.g., amplitude and phase) for each receiving antenna and each transmitting antenna port. The full set of channel estimates includes one estimate for each transmitting antenna port and each receiving antenna pair. The UE performs CSI estimation on the configured CSI-RS resources to obtain channel estimates between the gNB and the UE. CSI report

[0081] CSI reporting, also known as CSI feedback, involves the transmission of information from the UE to the gNB based on CSI estimates. In some embodiments, multiple feedback mechanisms are available for use by the UE, one of which is a method of providing feedback based on scalar quantization. In some embodiments, the gNB transmits instructions on which feedback mechanism to use, among the provided method based on scalar quantization and one or more other methods. Another of the available mechanisms may be, for example, one of the existing codebook-based mechanisms. Which feedback mechanism a given UE uses may be determined based on explicit or implicit signaling from the base station, or it may be determined based on other conditions.

[0082] Determining an estimated channel between a transmitter and a receiver, for example between a base station and an UE, involves the transmitter transmitting a reference signal and the receiver receiving the reference signal. The receiver measures the received reference signal and determines how the known reference signal has changed and whether that change is due to channel influence.

[0083] Vector quantization, also known as "block quantization" or "pattern matching quantization," can be used for lossy data compression. Values ​​from a multidimensional vector space are encoded into a finite set of values ​​from a lower-dimensional discrete subspace. Lower-dimensional spatial vectors can use less memory space, and therefore the data is compressed. Vector quantization can be performed by projection or using a codebook.

[0084] The set of discrete amplitude levels is quantized together rather than each sample being quantized separately. Consider a k-dimensional vector [x1, x2, …, x k of amplitude levels. This is compressed by selecting the closest matching vector from a set of n-dimensional vectors [y1, y2, …, y] where n < k. All possible combinations of the n-dimensional vectors [y1, y2, …, y k form the vector space to which all the quantization vectors belong.

[0085] In some situations, only the index of the codeword within the codebook is transmitted instead of the quantization value. This saves space and achieves more compression.

[0086] In some embodiments, the representation of the channel H that undergoes vector quantization is represented as a matrix or a tensor. H = C × 1B T × 2B F × 3B S Here, B T , B F , and B S are the basis matrices for the time domain, frequency domain, and spatial domain respectively. C is a matrix that contains the channel parameters fed back to the transmitter.

[0087] When the antenna array at the transmitter is a uniform planar antenna array, the basis matrix B S for the spatial domain may be a two-dimensional discrete Fourier transform (2D-DFT).

[0088] When the antenna array at the transmitter is a non-uniform planar antenna array, the basis matrix B S for the spatial domain can be represented in the following form. B S = A · B DFT Here, the matrix A may be related to the shape of the non-uniform antenna array.

[0089] In some embodiments, matrix A may be configured for receivers by broadcast or multicast signaling via the network. In some embodiments, matrix B DFT This may be predefined, for example, in telecommunications standards.

[0090] In some embodiments, the time-domain basis matrix B T When is constructed as the identity matrix, only spatial and frequency domain vector quantization applies, and the channel matrix or tensor H can be expressed as follows: H=B S ·C·B F or

number

[0091] Time and frequency domain basis matrix B T and B F When each of these is constructed as an identity matrix, only spatial-domain vector quantization is applied, and the channel matrix or tensor H can be expressed as follows: H=B S ·C

[0092] In some embodiments, the time-domain, frequency-domain, and spatial-domain basis matrices may be configured independently. For example, a base station may transmit configuration information to the UE that enables the UE to configure itself to use an appropriate time-domain basis matrix, frequency-domain basis matrix, or spatial-domain basis matrix. Furthermore, the configuration may be used to modify or update a previously configured time-domain basis matrix, frequency-domain basis matrix, or spatial-domain basis matrix.

[0093] In some embodiments, the basis matrix or tensor may be the Kroneck product of two or more basis matrices comprising regions.

[0094] In some embodiments, one or more basis matrices from the time domain, frequency domain, or spatial domain may be predefined, for example, in a telecommunications standard. In some embodiments, one or more basis matrices from the time domain, frequency domain, or spatial domain may be communicated by the base station as part of the configuration information transmitted to the UE. Examples of predefined basis matrices may include the identity matrix, DFT matrix, and chirp matrix.

[0095] In some embodiments, the number of regions of the vector projection (selected from space, time, and frequency) may be configured by the base station. For example, the number of regions may be part of the configuration information transmitted by the base station.

[0096] In some embodiments, the number of regions of the vector projection (selected from space, time, or frequency) may be associated with a reference signal (RS) configured for CSI measurement. The type of RS may be a CSI-RS, or another type of RS that can be used to determine the CSI.

[0097] Vector quantization is suitable for determining CSI feedback across one or more domains. Measurements for determining the CSI are performed on a reference signal, which is measured in at least one of a continuous time window or block, a continuous frequency window or block, or a continuous space window or block. In some embodiments, with respect to the space domain, the receiver determining the CSI for CSI feedback purposes may recognize the antenna array structure. With respect to the frequency domain, the receiver determining the CSI for CSI feedback purposes may receive the reference signal across a continuous frequency band. With respect to the time domain, the receiver determining the CSI for CSI feedback purposes may receive the reference signal across a continuous frequency band time window.

[0098] Figure 10 shows an example of a spatial domain antenna array 1010 where each "X" on the 2D antenna array represents a pair of antennas for transmitting a reference signal used for CSI measurement and feedback; an example of a frequency domain resource 1020 showing multiple subbands for transmitting a reference signal used for CSI measurement and feedback; and an example of a time domain resource 1030 used for transmitting a reference signal used for CSI measurement and feedback.

[0099] To determine the CSI, the receiver measures channel information in one or more of the time domain, frequency domain, or spatial domain. The receiver may determine feedback to transmit to the transmitter in the form of a channel matrix or tensor. The receiver may feed back all eigenvectors of the channel matrix or tensor, or a subset of the eigenvectors of the channel matrix or tensor.

[0100] In some embodiments, the receiver may also feed back a precoding matrix used on the UE side that has been selected by the UE or is recommended by the UE.

[0101] Information about the antenna array is particularly relevant to the spatial basis matrix. Examples of different types of antennas in which information about the antennas can influence the spatial basis matrix include 2D and 3D antenna arrays. Figure 11 shows an example of a 2D planar antenna array 1110. The antenna arrangement is also shown in a 2D arrangement 1120. In some embodiments, for a uniform planar array, the spatial basis matrix may be expressed as follows: B S =B DFT

[0102] Figure 12 shows examples of an individual 3D antenna 1210 and an antenna array 1220 composed of multiple individual 3D antennas. In some embodiments, for a uniform planar array, the basis matrix of the spatial region may be expressed as follows: B S =A·B DFT

[0103] Figure 19 shows the coordinate transformation. In polar coordinates, the direction vector unit can be expressed as follows:

number

[0104] The position of antenna element n can be expressed as follows:

number

number

[0105] Using the Jacobi-Anger approximation, the steering vector can be expressed as follows:

number

number

number

[0106] As a result, the steering vector can be expressed as follows:

number

number

[0107] In some embodiments, the CSI-RS is configured as a chirp signal, for example, a sensing CSI-RS. In such cases, the basis matrix may be at least one of either a frequency-domain basis matrix or a spatial-domain basis matrix. In a particular example, when the CSI-RS is a chirp signal, the frequency-domain basis matrix may be based on the following relationship: B freq =exp(j2πf i t+jπαt 2 )

[0108] Figure 13 shows an example of a chirp signal 1300 that can be used as CSI-RS.

[0109] In certain cases, when CSI-RS is a chirp signal, the spatial basis matrix may be based on the following relationship:

number

[0110] Figure 14 shows an example of a receiver in the form of a UE1420 in the near field of a one-dimensional antenna array of a transmitter in the form of a gNB1410 or base station. The antenna array has 2N Ant Includes +1 antenna. Figure 14 shows the variables θ0 and r0 for the antenna labeled "0" in the antenna array.

[0111] In some embodiments, the number of projections of the basis matrices for CSI quantization may be a subset of the complete orthogonal basis matrix set. Figure 15 shows an example of a complete orthogonal basis matrix 1500, consisting only of matrix elements 1510 within the circled portion. The portion may be constructed by identifying the matrix elements to be constructed and what the new constructed matrix elements are.

[0112] In some embodiments, oversampling of a complete orthogonal basis matrix set may be applied to the basis matrices for CSI quantization. Figure 16 shows an example of applicable weight coefficients, where O1 and O2 are oversampling coefficients.

[0113] In some embodiments, a transmitter, which may be a base station, transmits configuration information, including vector quantization configuration information, to a receiver, which may be a UE.

[0114] In some embodiments, the vector quantization configuration information may include an indication of what to quantize. In certain examples, this may include the fact that the vector quantization is intended to quantize the top two eigenvectors of a channel matrix or tensor representing the channels of a matrix or tensor between a transmitter and a receiver.

[0115] In some embodiments, the vector quantization configuration information may include information about the basis matrix configuration. For example, the vector quantization configuration information may indicate that the basis matrix is ​​a DFT basis matrix in at least one of the spatial domain or frequency domain, or that the basis matrix is ​​a time domain discrimination matrix. Other basis matrix configuration information may be oversampling coefficients, and the oversampling coefficient in the spatial domain is O spatial = 4, or the oversampling coefficient in the frequency domain is O freq For example, =4.

[0116] In some embodiments, the vector quantization configuration information may include information about thresholds used when selecting channel parameters for feedback to the transmitter. Specific examples of thresholds in the spatial domain include

number

number

[0117] In some embodiments, the vector quantization configuration information may include information about the vector quantization precision. For example, the vector quantization precision may define the number of bits used to represent the amplitude and phase of the channel parameters. A specific example of the vector quantization precision information might be 3 bits for amplitude and 4 bits for phase for spatial domain parameters. A specific example of the vector quantization precision information might be 2 bits for amplitude and 4 bits for phase for frequency domain parameters.

[0118] When a receiver receives vector quantization configuration information, the receiver may be configured to use the provided vector quantization configuration information as part of determining the CSI and providing CSI feedback to the transmitter.

[0119] As part of the CSI process, the transmitter also sends configuration information to the receiver that identifies the type of reference signal or other relevant information about the reference signal, as well as other configuration information such as how and which CSI information should be sent back to the transmitter.

[0120] After the receiver receives configuration information and recognizes that a reference signal is being transmitted, the receiver measures the received reference signal and performs channel estimation based on the reference signal configuration.

[0121] The receiver then projects the CSI matrix or tensor onto the constructed basis matrix to obtain at least one channel parameter from the time domain, spatial domain, or frequency domain.

[0122] The receiver performs channel parameter quantization and transmits feedback information to the transmitter.

[0123] Figure 18 shows an example of a signal flow diagram 1800 for signaling between a transmitter 1801 and a receiver 1802. In some embodiments, the transmitter 1801 may be a base station and the receiver 1802 may be a UE. The examples described below describe a scenario where the transmitter is a base station and the receiver is a UE, but it should be understood that the transmitter is a UE and the receiver is a UE, or the transmitter is a UE and the receiver is a base station.

[0124] In step 1810, the transmitter 1801 transmits channel state information (CSI) configuration information, which includes vector quantization configuration information. The configuration information may also transmit other configuration information related to the receiver 1802 that performs the CSI measurement and the receiver 1802 that sends the CSI information back to the transmitter 1801.

[0125] As step 1820, the transmitter 1802 transmits a reference signal that the receiver will use to determine the CSI of the channel on which the reference signal is received.

[0126] In step 1830, the receiver 1802 measures the received reference signal and determines the CSI parameters of the measured reference signal by performing vector quantization based on the vector quantization configuration information received in step 1810.

[0127] In step 1840, the receiver transmits the CSI parameters determined in step 1830 to the transmitter.

[0128] In light of the above teachings, many modifications and variations of this disclosure are possible. Therefore, it should be understood that this disclosure may be implemented in ways other than those specifically described herein, within the scope of the appended claims. [Explanation of Symbols]

[0129] 100 Communication Systems 110 ED 110a ED 110b ED 110c ED 110d ED 110e ED 110f ED 110g ED 110h ED 110i ED 110j ED 120 Wireless Access Networks 120a Wireless Access Network 120b Wireless Access Network 120c Non-terrestrial communications network 130 Core Network 140 Public switched telephone network 150 Internet 160 Other Networks 170 network nodes 170a Network Node 170b Network Node 170c base station 172 Non-terrestrial transmission / reception points 190a Interface 190b interface 190c interface 190d Interface 201 Transmitter 203 Receiver 204 Antenna 208 memory 210 processors 252 Transmitter 253 Scheduler 254 Receiver 256 Antenna 258 memory 260 processors 272 Transmitter 274 Receiver 276 processors 278 memory 280 antennas 500 CSI-RS transmission 502 CSI Feedback Configuration 504 CSI measurement 506 CSI Report 510 Channel Estimation Block 512 channel estimation block 1010 Antenna Array 1020 Frequency Domain Resources 1030 Time Domain Resources 1110 2D Planar Antenna Array 1120 2D placement 1210 individual 3D antennas 1220 Antenna Array 1300 Chirp signal 1410 gNB 1420 UE 1500 Complete orthogonal basis matrices 1510 matrix elements

Claims

1. It is a method, A step of obtaining a quantized channel estimate for at least a subset of channel estimates by quantizing the channel estimate using scalar quantization, wherein the channel estimate is obtained for channel state information reference symbols (CSI-RS) transmitted across multiple transmission antenna ports. The steps include: transmitting channel state information (CSI) based on the quantized channel estimate; A method that includes this.

2. The step of performing compression of the quantized channel estimate in order to generate a compressed quantized channel estimate. It further includes, The method according to claim 1, wherein the step of transmitting channel state information (CSI) based on the quantized channel estimate includes the step of transmitting the compressed quantized channel estimate.

3. The steps include receiving a first signaling signal, When the first signaling indicates that scalar quantization should be performed on the channel estimates, the steps of performing the following are performed: obtaining each quantized channel estimate by quantizing the channel estimate using scalar quantization for at least a subset of the channel estimates; and transmitting channel state information (CSI) based on the quantized channel estimates. The method according to claim 1, further comprising:

4. The steps include receiving a second signaling signal, When the second signaling indicates the use of vector quantization for the channel estimate, the steps include: transmitting CSI feedback using the vector quantization; The method according to claim 1, further comprising:

5. The steps include receiving a signaling indicating the quantization accuracy applied to all channel estimates, The steps include: performing the quantization using the quantization precision indicated above; The method according to claim 1, further comprising:

6. The steps include receiving signaling that indicates the respective quantization precision applied to each channel estimate, The steps include: performing quantization of each channel estimate using the respective quantization precisions; The method according to claim 1, further comprising:

7. The method according to claim 5 or 6, wherein each of the quantization accuracies includes a first number of bits for amplitude and a second number for phase.

8. The steps include selecting the subset of the channel estimates to be fed back, The steps include transmitting instructions for a subset of the selected channel estimates that are being fed back, and The method according to claim 1, further comprising:

9. The method according to claim 8, wherein the step of selecting the subset of channel estimates to be fed back includes the step of applying a threshold based on the strongest channel estimate.

10. The method according to claim 1, wherein the at least subset of the channel estimates includes all of the channel estimates.

11. The step of receiving the signaling indicating the configuration of the transmitted CSI-RS. The method according to claim 1, further comprising:

12. It is a device, Processor and A computer-readable storage medium storing computer-executable instructions, wherein the computer-executable instructions, when executed by the processor, are stored in the device. For at least a subset of channel estimates, a quantized channel estimate is obtained by quantizing the channel estimate using scalar quantization, and the channel estimate is obtained for channel status information reference symbols (CSI-RS) transmitted across multiple transmission antenna ports. A computer-readable storage medium that transmits channel state information (CSI) based on the quantized channel estimates, and A device equipped with the following features.

13. The computer executable instruction is a computer executable instruction that, when executed by the processor, causes the device to To generate a compressed quantized channel estimate, the quantized channel estimate is compressed. Further including computer executable instructions, The apparatus according to claim 12, wherein transmitting channel state information (CSI) based on the quantized channel estimates includes transmitting the compressed quantized channel estimates.

14. The computer executable instruction is a computer executable instruction that, when executed by the processor, causes the device to The first signaling is received, When the first signaling indicates that scalar quantization should be performed on the channel estimates, the steps of obtaining a quantized channel estimate by quantizing the channel estimate using scalar quantization for at least a subset of the channel estimates, and transmitting channel state information (CSI) based on the quantized channel estimates are performed. The apparatus according to claim 12, further comprising computer executable instructions.

15. The computer executable instruction is a computer executable instruction that, when executed by the processor, causes the device to The second signaling signal was received. When the second signaling indicates that vector quantization should be used for the channel estimate, the CSI feedback should be transmitted using the vector quantization. The apparatus according to claim 12, further comprising computer executable instructions.

16. The computer executable instruction is a computer executable instruction that, when executed by the processor, causes the device to We receive a signal indicating the quantization accuracy applied to all channel estimates. Perform the quantization using the quantization precision indicated above. The apparatus according to claim 12, further comprising computer executable instructions.

17. The computer executable instruction is a computer executable instruction that, when executed by the processor, causes the device to The system receives signaling that indicates the respective quantization precision applied to each channel estimate. The respective channel estimates are quantized using the respective quantization accuracies. The apparatus according to claim 12, further comprising computer executable instructions.

18. The apparatus according to claim 16 or 17, wherein each of the quantization accuracies includes an indication of a first number of bits for amplitude and an indication of a second number for phase.

19. The computer executable instruction is a computer executable instruction that, when executed by the processor, causes the device to Select the subset of the channel estimates to be fed back, Transmit instructions for the selected subset of channel estimates that are being fed back. The apparatus according to claim 12, further comprising computer executable instructions.

20. It is a method, A step of receiving channel status information (CSI), wherein the CSI is transmitted based on quantized channel estimates, and for at least a subset of channel estimates, each quantized channel estimate is obtained by quantizing the channel estimate using scalar quantization, and the channel estimate is obtained for a CSI reference symbol (CSI-RS) transmitted across a plurality of transmission antenna ports. A method that includes this.

21. A non-temporary computer-readable storage medium, the computer-readable storage medium storing instructions that, when executed by the processor of the device, enable the device to perform the method according to any one of claims 1 to 11 and 20.

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