Methods and apparatus for communication

Abstract

Embodiments of this application provide a method and apparatus for communication. This application proposes a new concept called a “reference channel.” The communication device can acquire channel data samples in a time window and determine K reference channels based on the channel data samples. The K reference channels may be used to determine information for the downlink (DL) channel, thereby reducing the overhead related to the feedback of DL channel information in a MIMO system.

Description

[Technical Field]

[0001] This application relates to and claims priority to U.S. Provisional Patent Application No. 63 / 507,222, “A METHOD OF OBTAINING SPATIAL REFERENCE CHANNEL BY ONLINE / OFFLINE TRAINING,” filed on 9 June 2023. The disclosures of the aforementioned application are incorporated herein by reference in their entirety.

[0002] Embodiments of the present invention relate to the field of wireless technology, and more specifically to methods and apparatus for communication. [Background technology]

[0003] In wireless systems, multi-user multiple-input multiple-output (MU-MIMO) is typically used for the downlink (DL), with the base station (BS) being the transmitter and multiple user devices (UEs) being the corresponding receivers. The MIMO channels of multiple UEs are paired by a common precoder to multiplex over frequency and time resources. For higher throughput and system efficiency, modern MU-MIMO systems deploy many antenna ports over wider bandwidths. For example, in a terabit-MIMO (T-MIMO) system, the BS is expected to have 3072 antenna ports and the UEs 64 antenna ports over a 400 MHz bandwidth. MIMO channels become a three-dimensional tensor.

[0004] In large-scale MIMO systems, such as T-MIMO systems, how to estimate the downlink (DL) channel is a difficult problem that needs to be solved. [Overview of the Initiative]

[0005] Embodiments of this application provide a method and apparatus for communications that propose determining a reference channel based on channel data samples related to a wireless environment in order to facilitate channel estimation of DL channels from absolute estimation to relative estimation. [Means for solving the problem]

[0006] According to a first embodiment, a method for communication is provided, which can be performed by a communication device or a chip installed in a communication device. The method includes taking M channel data samples within a time window, wherein the M channel data samples relate to an environmental parameter set, where M is a positive integer, and determining K reference channels based on the M channel data samples, where K ≥ 1, where K is an integer.

[0007] In some embodiments of this application, a communication device can acquire a certain amount of channel data samples related to an environmental parameter set, for example, M channel data samples related to the environmental parameter set, and then determine K(k) reference channels based on the M channel data samples. The novel concepts of “channel data samples” and “reference channels” are proposed to facilitate channel estimation of DL channels from absolute estimation to relative estimation.

[0008] In one implementation of the first embodiment, the method further includes estimating a downlink (DL) channel between a transmitter and a receiver based on K reference channels.

[0009] In this implementation, K(or more) reference channels are determined such that the DL channel can be estimated based on the K(or more) reference channels, which simplifies the complexity of channel estimation in MIMO systems. In particular, in large-scale MIMO systems, the proposed solution enables computations related to pairing and precoder matrix calculations.

[0010] In one implementation of the first embodiment, the time window is predefined or configured.

[0011] The time window for acquiring channel data samples can be determined by the communication device in an appropriate manner, such as a predefined or configured method or by other means.

[0012] The following provides several implementations for obtaining M channel data samples within a time window.

[0013] In one implementation of the first embodiment, the method further includes receiving configuration information of a DL signal used to determine M channel data samples, and determining M channel data samples within a time window includes determining M channel data samples based on the DL signal within a time window.

[0014] In this implementation, M channel data samples can be acquired using DL signals. Note that DL signals refer to one or more DL signals.

[0015] In one implementation of the first embodiment, the method further includes transmitting configuration information of a detection signal used to determine M channel data samples, and determining M channel data samples in a time window includes determining M channel data samples in a time window based on echo signals corresponding to the detection signal.

[0016] In this implementation, M channel data samples may be obtained by detection.

[0017] In one implementation of the first embodiment, the method further includes transmitting a detection signal, determining M channel data samples within a time window, and determining M channel data samples within a time window based on an echo signal corresponding to the detection signal.

[0018] In this implementation, M channel data samples may be acquired by monostatic detection in the communication device.

[0019] In one implementation of the first embodiment, the method further includes transmitting configuration information of an uplink (UL) signal used to determine M channel data samples, and determining M channel data samples within a time window includes determining M channel data samples based on the UL signal within a time window.

[0020] In this implementation, M channel data samples can be acquired using the UL signal.

[0021] In one implementation of the first embodiment, estimating the DL channel between a transmitter and a receiver based on K reference channels (or more) further includes determining one or more first reference channels from the K reference channels (or more), wherein the distance between the first reference channels and the DL channel is less than or equal to a threshold.

[0022] In this implementation, the first reference channel(s) may be determined from K reference channels(s). The first reference channel(s) can be representative of the DL channels if the channel estimation of the first reference channel(s) satisfies the requirements, specifically, if the distance between the first reference channel(s) and the DL channels is below a threshold. Therefore, the reporting of DL channel information may be replaced with information from the first reference channel(s), for example, the index of the first reference channel(s). In this way, the feedback of DL channel information can be simplified, and the overhead associated with feedback can be reduced.

[0023] In one implementation of the first aspect, the method further includes monitoring the performance of one or more first reference channels to determine whether one or more first reference channels need to be updated, the performance including communication-related performance or intermediate performance.

[0024] In this implementation, the "representative channel" of the DL channel, i.e., one or more first reference channels, can be tracked by monitoring the performance of the representative channel, which supports high mobility scenarios.

[0025] In one implementation of the first aspect, the method further includes initiating an update of one or more first reference channels when one or more reference channels need to be updated.

[0026] In this implementation, the "representative channel" of the DL channel can be updated to support high-mobility scenarios.

[0027] According to a second embodiment, a communication device is provided that has the function of implementing either the method or the implementation form of the first embodiment.

[0028] According to a third aspect, a chip (or chip system) is provided. The chip may include at least one processor, the at least one processor being coupled to at least one memory. The at least one memory is configured to store one or more instructions and / or executable computer code. The at least one processor is configured to call one or more instructions and / or executable computer code, thereby enabling communications installed on the chip to perform the method and any possible implementation provided in the first aspect.

[0029] According to a fourth aspect, a communication system is provided. The communication system may include a communication device according to a second aspect.

[0030] According to a fifth aspect, a computer storage medium is provided for storing executable computer code, the executable computer code is used to execute one or more instructions for the method according to the first aspect or any possible implementation of the first aspect.

[0031] According to the sixth aspect, a computer program product including one or more instructions is provided, and when the computer program product is executed on a computer, the computer performs the method according to the first aspect or any possible implementation of the first aspect.

[0032] One or more embodiments are illustrated by corresponding accompanying drawings, and these illustrative descriptions and accompanying drawings do not constitute limitations to embodiments. Elements having the same reference numeral in the accompanying drawings are shown as similar elements, and the drawings are not limited to scale. [Brief explanation of the drawing]

[0033] [Figure 1] This is a schematic diagram of an application scenario according to one embodiment of this application. [Figure 2] An example of a communication system is shown. [Figure 3] Another example of an electronic device (ED) and a base station is shown. [Figure 4] This is an example of a channel model for a MIMO system. [Figure 5] This is a schematic flowchart of a communication method proposed by one embodiment of this application. [Figure 6] This is an example of a method according to an embodiment of this application. [Figure 7] This is an example of a method according to an embodiment of this application. [Figure 8] This is an example of a method according to an embodiment of this application. [Figure 9] This is an example of a method according to an embodiment of this application. [Figure 10] This is a schematic block diagram of a communication device according to one embodiment of the present application. [Figure 11] This is a schematic block diagram of a communication device according to one embodiment of the present application. [Figure 12] The dimensions of a TMIMO channel according to one embodiment of this application are shown. [Figure 13]This invention presents an example of vectorizing tensor-formatted MIMO channel samples according to one embodiment of this application. [Figure 14] This shows the selection of representative nodes based on a graph relating the "distance" between data samples. [Figure 15] This is an example of an embodiment of the present application. [Figure 16] This is an example of an embodiment of the present application. [Figure 17] This is an example of an embodiment of the present application. [Figure 18] This is an example of an embodiment of the present application. [Figure 19] An example of a basic module structure according to one embodiment of this application is shown. [Modes for carrying out the invention]

[0034] To gain a detailed understanding of the features and technical content of the embodiments of this application, implementations of the embodiments of this application are described in detail below with reference to the accompanying drawings, which are for reference and illustrative purposes only and do not limit the embodiments of this application. The following technical description includes numerous details to facilitate explanation and to provide a complete understanding of the disclosed embodiments.

[0035] Referring to Figure 1, a simplified schematic diagram of a communication system is provided as an illustrative, not limiting, example. The communication system 100 includes 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-110j (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 depend on or be independent of the radio access technology used in the communication system 100. The communication system 100 also includes a public switched telephone network (PSTN) 140, the Internet 150, and other networks 160.

[0036] 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 can 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 can provide a wide range of communication services and applications, such as earth monitoring, remote sensing, passive sensing and positioning, navigation and tracking, autonomous distribution and mobility, etc. The communication system 100 can 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 may result in what can be considered a heterogeneous network involving multiple layers. Compared to conventional communication networks, heterogeneous networks can achieve better overall performance through efficient multi-link joint operation, more flexible function sharing, and faster physical layer link switching between terrestrial and non-terrestrial networks.

[0037] Terrestrial and non-terrestrial communication systems can be considered subsystems of a communication system. In the illustrated example, the communication system 100 includes electronic devices (EDs) 110a-110d (collectively referred to as ED 110), radio access networks (RANs) 120a-120b, non-terrestrial communication networks 120c, a core network 130, a public switched telephone network (PSTN) 140, the Internet 150, and other networks 160. The RANs 120a-120b include their respective base stations (BSs) 170a-170b, which can generally be referred to as terrestrial transceiver points (T-TRPs) 170a-170b. The non-terrestrial communication network 120c includes access nodes 120c, which can generally be referred to as non-terrestrial transceiver points (NT-TRPs) 172.

[0038] Any ED 110 may be configured to interface with, access, or communicate with any other T-TRP 170a-170b and NT-TRP 172, the Internet 150, the core network 130, the PSTN 140, other networks 160, or any combination thereof. In some examples, ED 110a may communicate with T-TRP 170a for uplink and / or downlink transmits via interface 190a. In some examples, EDs 110a, 110b, and 110d may also communicate directly with each other via one or more sidelink air interfaces 190b. In some examples, ED 110d may communicate with NT-TRP 172 for uplink and / or downlink transmits via interface 190c.

[0039] Air interfaces 190a and 190b can use any suitable radio access technology, or similar communication technology. For example, communication system 100 can 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 can utilize other higher-dimensional signal spaces, which may involve combinations of orthogonal and / or non-orthogonal dimensions.

[0040] The air interface 190c can enable communication between the ED 110d and one or more NT-TRP 172 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.

[0041] RANs 120a and 120b communicate with the core network 130 to provide various services to EDs 110a, 110b, and 110c, such as voice, data, and other services. RANs 120a and 120b and / or the core network 130 may communicate directly or indirectly with one or more other RANs (not shown), which may or may not be directly serviced by the core network 130, and may or may not employ the same radio access technology as RANs 120a, RAN 120b, or both. The core network 130 may also function as a gateway access between (i) RANs 120a and 120b, or EDs 110a, 110b, and 110c, or both, and (ii) other networks (such as the PSTN 140, the Internet 150, and other networks 160). In addition, some or all of the ED 110a, 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, the ED 110a, 110b, and 110c may communicate with service providers or switches (not shown) and the Internet 150 via wired communication channels. The PSTN 140 may include a circuit-switched telephone network for providing basic telephone services (POTS). The Internet 150 may include a network of computers and / or subnets (intranets) and may incorporate protocols such as Internet Protocol (IP), Transmit Control Protocol (TCP), and User Datagram Protocol (UDP). The ED 110a, 110b, and 110c may be multimode devices capable of operating according to multiple radio access technologies and may incorporate multiple transceivers as necessary to support such operation.

[0042] Figure 3 shows another example of the ED 110 and base stations 170a, 170b, and / or 170c. The ED 110 is used to connect people, objects, machines, etc. The ED 110 can be widely used in a variety of scenarios, such as cellular communication, device-to-device (D2D), vehicle-to-everything (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, remote medical care, 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.

[0043] Each ED 110 represents any suitable end-user device for wireless operation, and among other possibilities, may include (or may be referred to as) devices such as UE, WTRU, mobile station, fixed or mobile subscriber unit, cellular telephone, STA, MTC device, PDA, smartphone, laptop, computer, tablet, wireless sensor, home electronic device, smartbook, vehicle, automobile, railroad, bus, train, or IoT device, industrial device, or equipment within the aforementioned devices (e.g., communication module, modem, or chip). Next-generation ED 110 may be referred to using other terms. Base stations 170a and 170b are T-TRPs and will be referred to as T-TRP 170 below. Also, as shown in Figure 3, the NT-TRP will be referred to as NT-TRP 172 below. Each ED 110 connected to T-TRP 170 and / or NT-TRP 172 may 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 or more of the connection availability and connection needs.

[0044] ED 110 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 alternatively be panels. 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 a signal for wireless or wired transmission and / or processing a signal received wirelessly or wired. Each antenna 204 includes any suitable structure for transmitting and / or receiving wireless or wired signals.

[0045] The ED 110 includes at least one memory 208. The memory 208 stores instructions and data used, generated, or collected by the ED 110. For example, the memory 208 can store software instructions or modules executed by the processing unit 210, which may be configured to implement 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(s). 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, or on-processor cache.

[0046] ED 110 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 users or other devices in the network. Each input / output device includes any suitable structure for providing information to or receiving information from a user, including network interface communication, such as a speaker, microphone, keypad, keyboard, display, or touchscreen.

[0047] ED 110 further includes a processor 210 for performing operations related to preparing transmissions for uplink transmissions to NT-TRP 172 and / or T-TRP 170, processing downlink transmissions received from NT-TRP 172 and / or T-TRP 170, and processing sidelink transmissions to and from another ED 110. Processing operations related to preparing transmissions for uplink transmissions may include operations such as coding, modulation, transmit beamforming, and generation of symbols for transmission. Processing operations related to processing downlink transmissions may include operations such as receive beamforming, demodulation, and decoding of received symbols. Depending on the embodiment, downlink transmissions may be received by a receiver 203, possibly using receive beamforming, and the processor 210 may extract signaling from the downlink transmissions (e.g., by detecting and / or decoding the signaling). An example of signaling may be a reference signal transmitted by NT-TRP 172 and / or T-TRP 170. In some embodiments, the processor 276 implements transmit beamforming and / or receive beamforming based on beam direction indications, e.g., beam angle information (BAI), received from 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 detecting synchronization sequences and decoding and acquiring system information. In some embodiments, the processor 210 may perform channel estimation using, for example, a reference signal received from NT-TRP 172 and / or T-TRP 170.

[0048] 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.

[0049] The processor 210, and the processing components of 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 (for example, in memory 208). Alternatively, some or all of the processing components of the processor 210, and the processing components of the transmitter 201 and receiver 203, may be implemented using dedicated circuits such as programmed field-programmable gate arrays (FPGAs), graphical processing units (GPUs), or application-specific integrated circuits (ASICs).

[0050] In some embodiments, T-TRP 170 may be known by other names such as base station, base transceiver station (BTS), radio base station, network node, network device, network-side device, transmit / receive node, node B, evolved node B (enode B or eNB), home enode B, next-generation node B (gNB), transmit point (TP), site controller, access point (AP), or wireless router, relay station, remote radio head, ground node, ground network device, or ground base station, BBU, RRU, radio unit (RU), AAU, RRH, CU, DU, positioning node, etc. T-TRP 170 may be a macro BS, pico BS, relay node, donor node, etc., or a combination thereof. T-TRP 170 may refer to a forged device or apparatus (e.g., communication module, modem, or chip) within the devices described above.

[0051] CU (or CU control plane (CP) and CU user plane (UP)), DU, or RU may be known by other names in some embodiments. For example, in an open RAN (ORAN) system, CU may be called open CU (O-CU), DU may be called open DU (O-DU), CU-CP may be called open CU-CP (O-CU-CP), CU-UP may be called open CU-UP (O-CU-CP), and RU may be called open RU (O-RU). Any one of CU (or CU-CP, CU-UP), DU, or RU may be implemented via a software module, a hardware module, or a combination of a software module and a hardware module.

[0052] In some embodiments, portions of the T-TRP 170 may be distributed. For example, some modules of the T-TRP 170 may be located away from the equipment housing the antennas of the T-TRP 170 and may be coupled to the equipment housing the antennas via a communication link (not shown) which may also be known as a fronthaul, such as a Common Public Radio Interface (CPRI). Thus, in some embodiments, the term T-TRP 170 may also refer to network-side modules that perform processing operations such as determining the location of the ED 110, resource allocation (scheduling), message generation, and coding / decoding, and which are not necessarily part of the equipment housing the antennas of the T-TRP 170. Modules may also be coupled to other T-TRPs. In some embodiments, the T-TRP 170 may actually be multiple T-TRPs working together to serve the ED 110, for example, via coordinated multipoint transmission.

[0053] The T-TRP 170 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 may alternatively be panels. The transmitter 252 and receiver 254 may be integrated as a transceiver. The T-TRP 170 further includes a processor 260 for performing operations related to preparing a transmission for downlink transmission to ED 110, processing an uplink transmission received from ED 110, preparing a transmission for backhaul transmission to NT-TRP 172, and processing a transmission received from NT-TRP 172 via backhaul. Processing operations related to preparing a transmission for downlink or backhaul transmission may include operations such as coding, modulation, precoding (e.g., MIMO precoding), transmit beamforming, and symbol generation for transmission. Processing operations related to processing received transmissions in the uplink or via backhaul may include operations such as receive beamforming, and demodulation and decoding of received symbols. In some embodiments, the processor 260 may also perform operations related to network access (e.g., initial access) and / or downlink synchronization, such as generating the contents of a synchronous signal block (SSB) and generating system information. The processor 260 may also generate beam direction indications, e.g., BAI, which can be scheduled for transmission by the scheduler 253. In some embodiments, the processor 260 may perform 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. 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. Any signaling generated by the processor 260 is transmitted by the transmitter 252. The term "signaling" as used herein may alternatively be referred to as control signaling.Dynamic signaling may be transmitted in 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 in a data channel, such as a physical downlink shared channel (PDSCH).

[0054] The scheduler 253 may be coupled to the processor 260. The scheduler 253 may be contained within or operate separately from the T-TRP 170, and may schedule uplink, downlink, and / or backhaul transmissions, including issuing scheduling permissions and / or configuring scheduling-free ("configured permission") 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 be configured to implement some or all of the functions and / or embodiments described herein and may store software instructions or modules executed by the processor 260.

[0055] 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 implement a scheduler 253. Although not shown, memory 258 may form part of the processor 260.

[0056] 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, for example, 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.

[0057] Although the NT-TRP 172 is shown merely as a drone as an example, the NT-TRP 172 can be implemented in any suitable non-terrestrial form. The NT-TRP 172 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. The NT-TRP 172 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 alternatively be a panel. The transmitter 272 and receiver 274 may be integrated as a transceiver. The NT-TRP 172 further includes a processor 276 for performing operations related to preparing a transmission for a downlink transmission to ED 110, processing an uplink transmission received from ED 110, preparing a transmission for a backhaul transmission to T-TRP 170, and processing a transmission received from T-TRP 170 via backhaul. Processing operations related to preparing a transmission for downlink or backhaul transmission may include operations such as coding, modulation, precoding (e.g., MIMO precoding), transmit beamforming, and symbol generation for transmission. Processing operations related to processing a received transmission on uplink or via backhaul may include operations such as receive beamforming, and demodulation and decoding of the received symbol. In some embodiments, the processor 276 implements transmit 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 can generate signaling to configure one or more parameters of, for example, the ED 110. In some embodiments, the NT-TRP 172 implements physical layer processing but does not implement higher layer functions such as functions in the medium access control (MAC) or radio link control (RLC) layer. This is just an example, and more generally, the NT-TRP 172 may implement higher layer functions in addition to physical layer processing.

[0058] The NT-TRP 172 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.

[0059] The processor 276 and the processing components of the 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 processor 276 and the processing components of the transmitter 272 and receiver 274 may be implemented using dedicated circuitry such as a programmed FPGA, GPU, or ASIC. In some embodiments, the NT-TRP 172 may actually be multiple NT-TRPs working together to serve the ED 110, for example, via coordinated multipoint transmission.

[0060] T-TRP 170, NT-TRP 172, and / or ED 110 may include other components, which are omitted for clarity.

[0061] MIMO technology enables an antenna array of multiple antennas to perform signal transmission and reception to meet high transmission rate requirements. The ED 110 and T-TRP 170, and / or NT-TRP described above use MIMO to communicate over a wireless resource block. MIMO utilizes multiple antennas in the transmitting and / or receiving devices to transmit parallel wireless signals over the wireless resource block. MIMO can beamform parallel wireless signals for reliable multipath transmission over the wireless resource block. MIMO can combine parallel wireless signals carrying different data to increase the data rate of the wireless resource block.

[0062] In recent years, MIMO (Major MIMO) wireless communication systems with the above-mentioned T-TRP 170 and / or NT-TRP 172, which are composed of numerous antennas, have attracted greater attention from academia and industry. In a major MIMO system, the T-TRP 170 and / or NT-TRP 172 generally consist of more than 10 antenna units (such as 128 or 256) and serve dozens of ED 110s (such as 40). The numerous antenna units of the T-TRP 170 and / or NT-TRP 172 significantly increase the spatial degrees of freedom of wireless communication, greatly improving transmission speed, spectral efficiency, and power efficiency, and significantly eliminating interference between cells. By increasing the number of antennas, the size of each antenna unit can be reduced, lowering costs. Using the spatial degrees of freedom provided by the large number of antenna units, the T-TRP 170 and / or NT-TRP 172 in each cell can communicate with many ED 110s within the cell on the same time-frequency resources, thus greatly increasing spectral efficiency. The numerous antenna units of the T-TRP 170 and / or NT-TRP 172 also allow each user to have better spatial directivity for uplink and downlink transmission. Therefore, the transmit power of the T-TRP 170 and / or NT-TRP 172 and ED 110 is reduced, and power efficiency is increased. When the number of T-TRP 170 and / or NT-TRP 172 antennas is sufficiently large, the random channels between each ED 110 and the T-TRP 170 and / or NT-TRP 172 can approach orthogonality. The effects of interference and noise between the cell and the user can be eliminated. Due to the multiple advantages described above, large-scale MIMO systems have a good outlook for applications.

[0063] A MIMO system may include a receiver connected to a receiving (Rx) antenna, a transmitter connected to a transmitting (Tx) antenna, and a signal processor connected to both the transmitter and receiver. Each of the receiving and transmitting antennas may include multiple antennas. For example, the receiving antenna may have a uniform linear array (ULA) antenna array in which multiple antennas are arranged in a line at equal intervals. When a radio frequency (RF) signal is transmitted through the transmitting antenna, the receiving antenna can receive the signal reflected back from a target in front of it.

[0064] In this application, the central device may be network node 170a or 170b in Figure 1, and the user device may be one of ED 110a to 110j in Figure 1; or the central device may be one of T-TRP 170a to 170b and NT-TRP 172 in Figure 2, and the user device may be one of ED 110a to 110d in Figure 2; or the central device may be T-TRP 170 or NT-TRP 172 in Figure 3, and the user device may be ED 110 in Figure 3.

[0065] Figure 4 shows an example of a channel model for a MIMO system. The transmitter is connected to four Tx antennas x1 to x4, and the receiver is connected to four Rx antennas y1 to y4, and a transmit channel may be formed between each Tx antenna and each Rx antenna. For example, an RF signal transmitted via x1 may be received at y2 via channel h21. An RF signal transmitted via x3 may be received at y1 via channel h13.

[0066] In MIMO systems, channel estimation must be performed on the uplink or downlink channel to implement functions such as system synchronization, channel information feedback, and data transmission. Channel estimation refers to the process of reconstructing or restoring the received signal to compensate for signal distortion caused by channel fading and noise. In channel estimation, reference signals transmitted by the transmitter can be used to track changes in the time domain and / or frequency domain of the channel in order to reconstruct or restore the received signal. Reference signals are sometimes referred to as pilot signals, reference sequences, etc., and will be described as reference signals below for ease of understanding. Reference signals include, for example, channel status information reference signals (CSI-RS), sounding reference signals (SRS), demodulation reference signals (DMRS), phase tracking reference signals (PT-RS), or cell reference signals (CRS). The reference signals listed above are merely examples and do not constitute any limitation to this application. This application does not rule out the possibility that other reference signals may be defined in future protocols to implement the same or similar functions.

[0067] To facilitate understanding of the embodiments of this application, the CSI-RS will be described in detail by the following example. The CSI-RS is primarily used for downlink channel estimation corresponding to physical antenna ports. For example, a receiving device (i.e., a user device) may perform channel estimation for each physical antenna port based on the CSI-RS transmitted by a transmitting device (i.e., a central device) and feed back channel status information (CSI) based on the channel estimation results. The CSI may include relevant information such as a channel quality indicator (CQI), a precoding matrix indicator (PMI), a layer indicator (LI), and a rank indicator (RI). The CSI is used to reconfigure or precode the downlink channel. In some embodiments, the process by which the central device acquires the CSI may include: the central device transmitting a reference signal to the UE; the UE acquiring an estimated CSI value according to the received reference signal; the UE selecting a precoding vector from a codebook according to the estimated CSI value; the UE feeding back the index of the precoding vector to the central device; and the central device determining the CSI reconfiguration value by referring to the index of the precoding vector. The reconstructed CSI value may be the closest CSI to the true value of the CSI that can be obtained by the central device.

[0068] In one embodiment, the transmitting device maps a sequence of reference signals to a specific physical resource and transmits the reference signals through that specific physical resource. The sequence of reference signals and the physical resource are known to both the transmitting device and the receiving device that receives the reference signals. Therefore, the receiving device can perform channel estimation based on the known sequence of reference signals and the received signals.

[0069] A transmitting device can map a sequence to a physical resource in order to transmit a reference signal. A physical resource may include multiple resource elements, each of which is a physical resource allocated for transmitting a reference signal. For example, when DM-RS is transmitted, the resource element is included in a common resource block allocated for physical downlink shared channel (PDSCH) transmission.

[0070] The location of the physical resources of a reference signal is sometimes referred to as the reference signal pattern or pilot pattern. The location of the physical resources is generally described through at least one of the following dimensions: time, frequency, or space.

[0071] The time dimension can be represented by one or more time-domain resource units. Time-domain resource units may include, but are not limited to, symbols, orthogonal frequency division multiplexing (OFDM) symbols, slots, and the like. In some embodiments, time-domain units may be represented by symbol indices, OFDM symbol indices, or slot indices.

[0072] The frequency dimension can be represented by one or more frequency-domain resource units. A frequency-domain resource unit may include, but is not limited to, subcarriers or subbands. According to some embodiments, a frequency-domain unit may also be represented by a subcarrier index or a subband index. In some embodiments, a frequency-domain unit may also be represented by a resource element (RE) index, a resource block (RB) index, or a resource block group (RBG) index. An RE includes a symbol in the time domain and a subcarrier in the frequency domain, and the RE index may be used to indicate the location of a subcarrier. An RB includes a slot in the time domain and 12 consecutive subcarriers in the frequency domain. The RB index may be used to indicate the location of the 12 subcarriers. An RBG consists of a group of RBs, and the RBG index may be used to indicate the location of a group of subcarriers.

[0073] A spatial dimension can be represented by one or more spatial domain resource units. A spatial domain resource unit can be represented by an antenna port. In the embodiments of this application, an antenna port may be a Tx antenna. An antenna port may be identified by an antenna port index.

[0074] To facilitate understanding of the embodiments of this application, in the following exemplary description, symbol indexes are used to represent the location of time-domain resource units, subcarrier indexes are used to represent the location of frequency-domain resource units, and antenna port indexes are used to represent the location of spatial-domain resource units.

[0075] The channel estimation process described above is merely an illustrative example and does not constitute any limitation to this application. The channel estimation process is known in the prior art, and for the sake of brevity, a detailed description of the specific process is omitted herein.

[0076] The receiving device may be an ED (i.e., a user device) and the transmitting device may be a T-TRP or NT-TRP (i.e., a central device), or the receiving device may be a T-TRP or NT-TRP (i.e., a central device) and the transmitting device may be an ED (i.e., a user device). In some embodiments, when the reference signal in these embodiments is a downlink (e.g., CSI-RS), the transmitting device may be a central device and the receiving device may be a user device. When the reference signal in these embodiments is an uplink (e.g., SRS), the transmitting device may be a user device and the receiving device may be a central device. A single transmitting device can transmit a reference signal to one or more receiving devices, but the following embodiments, for simplicity, focus on the method between one transmitting device and one receiving device, and these examples are not intended to limit the scope of this application.

[0077] The embodiments of this application will be described in detail below with reference to the attached drawings.

[0078] The proposed method described in the embodiments of this application may be used in T-MIMO systems having a greater number of antenna ports and a larger bandwidth for the transmitter and receiver. The method may also be applied to conventional MIMO systems (e.g., 5G MIMO systems) or single-antenna systems, and is not limited to these applications.

[0079] In the following, a T-MIMO radio channel is used as an example to illustrate the solution proposed by this application, and this application shortens T-MIMO radio channel to radio channel or channel. This application is also applicable to high-dimensional signal spaces other than T-MIMO.

[0080] Generally speaking, embodiments of this application propose a method for communications that focuses on how to estimate DL MIMO channels in a MIMO system.

[0081] Figure 5 is a flowchart of a method (500) for communication proposed by one embodiment of the present application. Method (500) specifically includes the following steps 510 to 520. The steps of method (500) may be performed by a communication device or a chip installed in a communication device. The communication device may be a transmitting device or a receiving device, or a chip installed in a transmitting device or a receiving device. Optionally, the communication device may be a remote data center connected to a BS via a core network or the Internet.

[0082] In some embodiments of this application, a device that receives a reference signal(s) is referred to as a receiving device, for example, one or more UEs in a MIMO system, and a device that transmits a reference signal(s) is referred to as a transmitting device, for example, a BS in a MIMO system.

[0083] The method may be applied to a MIMO system including one transmitter and one or more receivers. The embodiment of the method will be described below using one transmitter and one receiver as an example. The transmitter may be a BS, and the receiver may be an UE. In this case, the communication device may be either a transmitter or a receiver.

[0084] In step 510, the communication device acquires M channel data samples within a time window, where M is a positive integer.

[0085] As described above, the communication device may be a transmitting device, a receiving device, or a remote data center. In one implementation, the transmitting device may have more powerful computing power and larger memory space than the UE, so M channel data samples may be acquired at the transmitting device. In another implementation, the channel data samples may be acquired at a remote data center connected to the BS via the core network or the internet. In yet another implementation, the M channel data samples may be acquired at one or more UEs, in particular when one or more UEs have powerful computing power and large memory space.

[0086] The communication device may have different methods for acquiring M channel data samples within a time window.

[0087] For example, in one implementation, the communication device may be the UE, and the time window is defined by the BS. The BS may also transmit configuration information to the UE, which indicates the period for the UE to acquire M channel data samples. This period of time is the time window.

[0088] In another implementation, the communication device may be the UE. The BS may send a first command indicating a start time to notify the UE to begin acquiring channel data samples, and a second command indicating an end time to notify the UE to stop acquiring channel data samples. Alternatively, the first and second commands may be sent in one message or in different messages, but are not limited to this.

[0089] In another implementation, the communication device may be an UE, and the BS transmits configuration information of the DL reference signal to perform channel estimation, and channel data samples can be obtained from the estimation results. The configuration information of the DL reference signal may include the number of times the BS transmits the DL reference signal, i.e., the number of times the UE receives the DL reference signal. The number of times the BS transmits the DL reference signal corresponds to a period of time in the time domain, and this period of time may be a time window.

[0090] In yet another implementation, the communication device may be a BS, which may determine the time window itself according to a policy for acquiring channel data samples.

[0091] In yet another implementation, the time window can be defined in the communication standard. By default, the communication device acquires channel data samples within the time window.

[0092] In this application, “time window” may refer to a single radio resource in the time domain, and the granularity of the time window is not limited. For example, the granularity of the time window may be any one of the following: frame, subframe, slot, transmit time interval (TTI), or orthogonal frequency division multiplexing (ODFM) symbol. For example, the time window may be N TTIs, where N is an integer.

[0093] In some embodiments of this application, M channel data samples are associated with an environmental parameter set. Details of the environmental parameter set will be described later.

[0094] In step 520, the communication device determines K reference channels (or more) based on M channel data samples.

[0095] A communication device may determine K reference channels based on M channel data samples, and some examples may include, but are not limited to, one of the following alternative forms.

[0096] Alternative form #1: The communication device may randomly select K channel data samples from M channel data samples.

[0097] Alternative form #2: The communication device can select K channel data samples from M channel data samples using several algorithms.

[0098] Alternative Form #3: The transmitter can score the "distance" between M channel data samples, and then select K channel data samples with the highest degree. "Degree" is a graph theory term indicating how many connections a node on a graph has. Nodes with higher degrees are called "hub" nodes on the graph. Nodes with higher degrees are considered more typical or representative. Note that each node on the graph represents a channel data sample in Alternative Form #3.

[0099] In embodiments of this application, a communication device can acquire a certain amount of channel data samples related to an environmental parameter set, for example, M channel data samples related to the environmental parameter set, and then determine K reference channels based on the M channel data samples. Novel concepts of "channel data samples" and "reference channels" are proposed. The K reference channels are determined such that the estimation of DL channels can be performed based on the K reference channels in order to facilitate channel estimation of DL channels from absolute estimation to relative estimation.

[0100] Method (500) may include step 530.

[0101] In step 530, the communication device estimates the DL channel between the transmitting device and the receiving device based on K reference channels (or more).

[0102] In this way, K reference channels are determined such that the DL channels can be estimated based on the K reference channels, which simplifies the complexity of channel estimation in MIMO systems. In particular, in large-scale MIMO systems, the proposed solution enables the calculation of pairing and precoder matrices, assuming that the channel estimation of the DL channels is obtained first.

[0103] K reference channels are determined to determine a representative of the DL channel between the transmitter and receiver in a MIMO system. If a representative whose channel conditions are close to the DL channel can be found from the K reference channels, the receiver can report the representative information instead of channel estimation for the DL channel, which is beneficial to channel estimation in a MIMO system, for example, by simplifying or reducing the complexity of channel estimation.

[0104] In some embodiments of this application, new concepts of “channel data sample” and “reference channel” are proposed. Alternatively, the reference channel may also be referred to as a mooring channel or anchor channel, but is not limited to these. To facilitate understanding of the embodiments of this application, several relevant technologies are introduced herein.

[0105] The radio channel between a transmitter and a receiver is primarily governed by the environment in which the transmitter and receiver are located. The inherent relationship between the environment and the radio channel is one embodiment of a ray tracing (RT) channel model that generates a channel response as a function of line-of-sight (LOS) and non-line-of-sight (NLOS) (reflection and / or diffusion), i.e., rays or clusters of rays with some randomness added. According to the RT channel model, the radio channel consists of a deterministic portion attributable to RT and a probabilistic portion attributable to random events. In one implementation of this application, the deterministic portion is several common characteristics between channels in a nearby region, which can be learned or acquired and represented as common information.

[0106] A radio channel may be affected to a greater or lesser extent by its environment, resulting in multipath fading. A radio ray or cluster (or group) of rays in a radio channel may be subject to reflection and diffusion of radio waves at surrounding physical surfaces, edges, or corners such as buildings, roads, buses, railways, and people, which can result in multiple radio paths at the receiving end. Some surfaces, edges, and corners are stationary (e.g., buildings, bridges, poles, roads, sidewalks), while others are moving (e.g., moving vehicles), which can cause timing variations (or fading) on ​​multiple radio paths. In practice, most moving entities can follow specific trajectories at specific speeds that are also regulated by the surrounding environment, which consists of several stationary entities (e.g., vehicles only travel on roads). Thus, a radio channel can be closely related to the environment in which the transmitting and receiving devices are located. The environment may be a generalized definition, and may be represented by an environment parameter set. The environment parameter set may include one or more environment parameters. One or more environmental parameters may include one or more of the following: spatial domain, frequency band, duplex mode (e.g., time-division duplex or frequency-division duplex, half-duplex or full-duplex), time or duration, weather, and data traffic (e.g., traffic mode or non-traffic mode; traffic mode refers to a period when data traffic exceeds a certain threshold; non-traffic mode refers to a period when data traffic is below a certain threshold).

[0107] Multiple radio channels located within the same environment can share several commonalities. These commonalities can be considered as common environmental prior knowledge regarding the radio channels. This common environmental prior knowledge is: Alternative form #1: Using one or more statistical functions with arguments, Alternative form #2: Using one or more matrices, Alternative form #3: It can be represented in various forms, including but not limited to one of the following: one or more trained artificial intelligence (AI) models (e.g., DNNs).

[0108] Common environmental prior knowledge can be learned or acquired for several wireless channels between a transmitting device (e.g., a central device) and multiple receiving devices (e.g., user devices) located within the same environment. The acquired common environmental prior knowledge related to the environment may be valid, persistent, and useful for wireless channels between receiving and transmitting devices entering the environment in the period after the common environmental prior knowledge has been acquired. Thus, the acquired common environmental prior knowledge can represent spatial and timing-persistent commonalities related to that environment.

[0109] The transmitting device can acquire and / or store multiple common environmental prior knowledge, each associated with a single environment. In some embodiments of this application, the common environmental prior knowledge can be learned or acquired from M channel data samples associated with the same environment (i.e., the same set of environmental parameters), where M is a positive integer. Alternatively, the common environmental prior knowledge may be referred to as common information in this application.

[0110] Different environments may or may not overlap in physical spatial domains, or different environments may or may not overlap between UL and DL, or different environments may or may not overlap across frequency bands.

[0111] In this embodiment, "spatial domain" may relate to a domain within a spatial domain, and "physical spatial domain" may relate to an actually existing domain or space.

[0112] The following are some examples of how communication devices acquire common information.

[0113] Example #1: A communication device may acquire common information related to the environment.

[0114] Example #2: A communication device may acquire two pieces of common information. The first piece of common information relates to a radio channel corresponding to a first spatial region, and the second piece of common information relates to a radio channel corresponding to a second spatial region. The two spatial regions may or may not overlap, may be adjacent or separate, and the spatial regions may be specified as sectors.

[0115] Example #3: A communication device may acquire two pieces of common information. The first piece of common information relates to a radio channel corresponding to a first physical spatial domain, and the second piece of common information relates to a radio channel corresponding to a second physical spatial domain. The first spatial domain may include the second spatial domain.

[0116] Example #4: The communication device may be a UE. The communication device may acquire two pieces of common information. The first piece of common information relates to the radio channel between the BS and the UE to which the UE can apply a first Rx decoder, and the second piece of common information relates to the radio channel between the BS and the UE to which the UE can apply a second Rx decoder. The UE can apply two different Rx decoders to the BS.

[0117] Example #5: The communication device may be a BS. The communication device may acquire two pieces of common information. The first piece of common information relates to a radio channel in a first frequency band between the BS and the UE(s), and the second piece of common information relates to a radio channel in a second frequency band between the BS and the UE(s). The two frequency bands may or may not overlap, and may be adjacent or separate.

[0118] Example #6: The communication device may be a BS. The BS can obtain two pieces of common information. The first piece of common information relates to the UL radio channel between the BS and the UE(s), and the second piece of common information relates to the DL radio channel between the BS and the UE(s).

[0119] Furthermore, the common information acquired by the communication device may be a combination of the examples above. Moreover, the common information may change over time.

[0120] Furthermore, any common information described above can be obtained from several channel data samples (which may also be referred to as channel samples, data sample sets, training datasets, etc.), for example, from M channel data samples, which can be stored and prepared in the following ways, including but not limited to one of the following methods:

[0121] Alternative form #1: The communication device may be a BS or an UE. Channel data samples may be measured and then stored in history by either the BS or UE(s), or both. For example, the BS may use a UL-SRS sounding channel to store channel data samples. The UE(s) may estimate the DL channel by CSI-RS and then feed back the CSI to the BS storing the channel data samples.

[0122] Alternative form #2: The communication device may be a BS. Channel data samples may be fed back by several physical reference receivers, which may be deployed at several key or random locations in the target environment, receive DL signals from the BS, estimate DL channels, and then feed back those estimated DL radio channels (preferably in a compressed format) as channel data samples to the BS, which stores the estimated DL radio channels as channel data samples.

[0123] Alternative form #3: Communication can obtain channel data samples from a digital environment simulator. The channel data samples may be virtually generated by the digital environment simulator, which may be referred to as a digital twin of the target environment.

[0124] The channel data samples and environmental parameter sets are described in detail above.

[0125] Some detailed examples of method (500) are given below.

[0126] Figure 6 shows an example of a method (500) according to one embodiment of the present application. In this example, the device may be a UE. The UE can receive configuration information of one or more DL signals from a BS. The configuration information indicates radio resources in the time domain and / or frequency domain. The configuration information may further indicate other information relating to one or more DL signals. For example, the configuration information may further indicate a time window. The configuration information is used by the UE to receive one or more DL signals. The DL signals are transmitted within the time window. Thus, the UE can receive one or more DL signals from the BS according to the configuration information. Within the time window, the UE can determine M channel data samples based on one or more DL signals. For example, the UE obtains M channel data samples by performing channel measurements using one or more DL signals. For example, one or more DL signals may be one or more channel status information reference signals (CSI-RS).

[0127] It should be noted that the way BS indicates the time window is merely an example, and the time window can be determined using any suitable method described in step 510.

[0128] Figure 7 shows an example of a method (500) according to one embodiment of the present application. In this example, the device may be a BS. The BS may transmit configuration information of one or more uplink (UL) signals to the UE. The configuration information is used by the UE to transmit one or more UL signals. The UE may transmit one or more UL signals according to the configuration information, and the BS may obtain M channel data samples by performing channel measurements using one or more UL signals. For example, one or more UL signals may be one or more UL RS signals.

[0129] One or more UL signals are transmitted within a time window, and signal measurements are performed within the time window. The time window may be configured using the configuration information of one or more UL signals, or the time window may be configured using any suitable method described in step 510.

[0130] Figure 8 shows an example of method (500) according to one embodiment of the present application. This example is shown in a flowchart of method (600). The device may be a BS or an UE. In step 610, the device may transmit one or more sensing signals. In step 620, the device performs a signal measurement using one or more echo signals corresponding to one or more sensing signals to acquire M channel data samples. Figure 8 shows an example of monostatic sensing. One or more sensing signals may be transmitted within a time window, and the signal measurement may be performed within a time window. In this example, the time window may be configured using any suitable method described in step 510. For example, the time window may be configured by the BS itself or by a communication standard, etc.

[0131] Figure 9 shows an example of method (500) according to one embodiment of the present application. In this example, the device may be a UE. The BS can transmit configuration information of one or more sensing signals to the UE. The configuration information is used by the UE to transmit one or more sensing signals. The BS obtains M channel data samples by performing signal measurements using echo signals corresponding to one or more sensing signals.

[0132] The detection signal may be transmitted within a time window, which may be configured using any suitable method described in step 510, and this is not repeated.

[0133] After the communication device has determined K reference channels, it may continue to update the set of K reference channels. For example, the communication device may retire some old reference channels, register some new reference channels, and maintain or change the size (i.e., K) of the set of reference channels.

[0134] As described above, the communication device can estimate the DL channel between the transmitting device and the receiving device based on K(K) reference channels.

[0135] Specifically, the communication device determines one or more first reference channels from K reference channels, and the distance between the first reference channels and the DL channels is less than or equal to a threshold. The distance between the DL channels and the first reference channels is a similarity metric that can be used to represent the similarity between the DL channels and the first reference channels.

[0136] One or more first reference channels may be determined by channel estimation (i.e., channel measurement) of the DL channel and K(or more) reference channels. One or more first reference channels may be selected from K(or more) reference channels as representative(or more) of the DL channel. The communication device may be a receiving device in a MIMO system. In some embodiments, one or more first reference channels may be determined by the receiving device.

[0137] Method (500) may further include steps 540 and 550.

[0138] In step 540, the communication device monitors the performance of one or more first reference channels to determine whether one or more first reference channels need to be updated.

[0139] In some implementations, performance may include communication-related performance or intermediate performance. For example, communication-related performance may include the block error rate (BLER) and channel quality indicators (CQI). Here, intermediate performance may be evaluated by a similarity metric between the DL channel and the first reference channel.

[0140] For example, if the similarity metric value between the DL channel and the first reference channel is less than or equal to a threshold, e.g., a first threshold, it means that the first reference channel does not need to be updated. If the similarity metric value between the first channel and the first reference channel is greater than a threshold, e.g., a second threshold, it means that the first reference channel needs to be updated. The communication device can retire the first reference channel and select a new one.

[0141] If one or more first reference channels need to be updated, method (500) may further include step 550.

[0142] In step 550, the communication device initiates updating one or more first reference channels if one or more first reference channels need to be updated.

[0143] Updating one or more first reference channels may involve updating the number of first reference channels, or removing some older first reference channels and registering some new first reference channels. For example, if only one first reference channel exists and the distance between the first reference channel and the first channel is greater than or equal to a second threshold, the first reference channels need to be updated.

[0144] In some embodiments, the K reference channels may be updated, for example, the set of K reference channels may need to be updated when the environment in which the transmitting device and one or more receiving devices are located changes.

[0145] The method proposed by this application is described in detail above, and the communication device provided by this application is described in detail below.

[0146] Figure 10 is a schematic block diagram of a communication device 10 according to one embodiment of the present application. As shown in Figure 10, the device 10 includes a receiver module 11, a processing module 12, and a transmitter module 13.

[0147] The processing module 12 is configured to acquire M channel data samples within a time window, where M channel data samples are associated with an environment parameter set, where M is a positive integer, and to determine K reference channels based on the M channel data samples, where K ≥ 1, and K is an integer.

[0148] In one implementation, the time window is either predefined or configured.

[0149] In other implementations, the receiver module 11 is configured to receive configuration information of a downlink (DL) signal used to determine M channel data samples, and the processing module 12 is configured to determine M channel data samples based on the DL signal within a time window.

[0150] In yet another implementation, the transmitter module 13 is configured to transmit configuration information of a detection signal used to determine M channel data samples, and the processing module 12 is configured to determine M channel data samples based on echo signals corresponding to the detection signal within a time window.

[0151] In yet another implementation, the transmitter module 13 is further configured to transmit a detection signal, and the processing module 12 is configured to determine M channel data samples based on the echo signal corresponding to the detection signal within a time window.

[0152] In yet another implementation, the transmitter module 13 is further configured to transmit configuration information of the uplink UL signal used to determine M channel data samples, and the processing module 12 is configured to determine M channel data samples based on the UL signal within a time window.

[0153] In yet another implementation, the processing module 12 is configured to determine one or more first reference channels from K reference channels, and the distance between the first reference channels and the DL channels is less than or equal to a threshold.

[0154] In yet another implementation, the processing module 12 is configured to monitor the performance of one or more first reference channels in order to determine whether one or more first reference channels need to be updated, and the performance includes communication-related performance or intermediate performance.

[0155] In yet another implementation, the processing module 12 is configured to initiate updating of one or more first reference channels if one or more reference channels need to be updated.

[0156] The apparatus 10 in this application may correspond to a communication device in any one of the embodiments of the method described above, and the operation and / or function of the apparatus 10 is intended to implement the corresponding steps of the method described above. For brevity, the details will not be repeated here.

[0157] Optionally, the transmitter module 13 and the receiver module 11 may be implemented by transceivers, and the processing module 12 may be implemented by a processor.

[0158] Referring to Figure 11, the communication device 20 may include a transceiver 21. Optionally, the communication device may further include a processor 22 and a memory 23. The memory 23 may be configured to store data, information, code, or instructions, etc., executed by the processor 22, to cause the communication device 20 to perform the operations of the communication device in the corresponding embodiment.

[0159] The processor 22 may be an integrated circuit chip and may have signal processing capabilities. In one embodiment of the process, the steps in the above-described embodiment of the method may be implemented by using hardware integrated logic circuits in the processor or by using instructions in the form of software. The processor 22 may be a general-purpose processor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), or another programmable logic device, discrete gate or transistor logic device, or discrete hardware component. All methods, steps, and logic block diagrams disclosed in these embodiments of the present application may be implemented or executed. The general-purpose processor may be a microprocessor, or the processor may be any conventional processor, etc. The steps of the methods disclosed in embodiments of the present invention may be performed and completed directly by a hardware decoding processor, or they may be performed and completed using a combination of hardware and software modules in the decoding processor. The software modules may reside in storage media known in the art, such as random access memory (RAM), flash memory, read-only memory (ROM), programmable read-only memory (PROM), electrically erasable programmable memory, registers, etc. The storage medium is placed in memory, the processor reads the information from memory, and, in combination with the processor's hardware, completes the steps of the method described above.

[0160] It will be understood that the memory 23 in embodiments of the present invention may be volatile memory or non-volatile memory, or may include both volatile and non-volatile memory. Non-volatile memory may be ROM, programmable read-only memory (programmable ROM, PROM), erasable programmable read-only memory (erasable PROM, EPROM), electrically erasable programmable read-only memory (electrically EPROM, EEPROM), or flash memory. Volatile memory may be RAM, which may be used as an external cache. Many forms of RAM may be used, but are not limited to examples, such as static random access memory (static RAM, SRAM), dynamic random access memory (dynamic RAM, DRAM), synchronous dynamic random access memory (synchronous DRAM, SDRAM), double data rate synchronous dynamic random access memory (Double Data Rate SDRAM, DDR SDRAM), enhanced synchronous dynamic random access memory (enhanced SDRAM, ESDRAM), synch link dynamic random access memory (synch Link DRAM, SLDRAM), and direct Rambus dynamic random access memory (direct Rambus RAM, DR RAM). The storage and methods of the systems described herein are intended to include, but are not limited to, these and other suitable storage.

[0161] One embodiment of this application further provides a communication system. The communication system comprises a communication device 10 and a communication device 30 according to any of the embodiments described above.

[0162] One embodiment of the present application further provides a computer storage medium capable of storing one or more instructions for performing any of the methods described above.

[0163] The storage medium may optionally be memory 23 or 43.

[0164] One embodiment of the present application further provides a computer program product that can store one or more instructions for performing any of the methods described above.

[0165] In the embodiments of this application, "and / or" describes an association between related objects and indicates that three relationships may exist. For example, A and / or B may represent the following three cases: namely, only A exists, namely, both A and B exist, and namely, only B exists. The letter " / " generally indicates an "or" relationship between related objects. "At least one" means one or more. "At least one of A and B" similarly describes an association between related objects and indicates that three relationships may exist. For example, at least one of A and B may represent the following three cases: namely, only A exists, namely, both A and B exist, and namely, only B exists.

[0166] Technical terms such as "reference channel" and "channel data sample" do not have to be limited to a specific name; other names may be used.

[0167] Furthermore, the use of the singular forms "a," "an," and "the" in the embodiments of this application and the appended claims is also intended to include the plural form unless explicitly indicated herein by context.

[0168] Those skilled in the art will recognize, in combination with the examples described in the embodiments disclosed herein, that units and algorithmic steps can be implemented using electronic hardware or a combination of computer software and electronic hardware. Whether a function is performed using hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art may use different methods to implement the functions described for each specific application, but the embodiments should not be considered to exceed the scope of this application.

[0169] For convenience and brevity, the detailed operating processes of the systems, apparatus, and units described above may refer to the corresponding processes in the embodiments of the methods described above, and details will not be described again here, as will be understood by those skilled in the art.

[0170] In the various embodiments provided in this application, the disclosed systems, apparatus, and methods may be implemented in other ways. For example, the embodiments of the apparatus described are merely examples. For example, unit division is a logical functional division, and other division methods may be used in actual embodiments. For example, multiple units or components may be coupled or integrated into other systems, or some features may be ignored or not performed. In addition, the mutual coupling, direct coupling, or communication connection shown or discussed may be implemented by using various communication interfaces. Indirect coupling or communication connection between apparatus or units may be implemented electronically, mechanically, or in other forms.

[0171] In addition, the functional units in the embodiments of this application may be integrated into a single processing unit, each unit may exist physically independently, or two or more units may be integrated into a single unit.

[0172] When a function is implemented in the form of a software function unit and sold or used as an independent product, the function may be stored on a computer-readable storage medium. The technical solution of this application may be implemented in the form of a software product. The software product is stored on a storage medium and includes a number of instructions for instructing a computer device (which may be a personal computer, server, network device, etc.) to perform all or part of the steps of the method described in the embodiments of this application. The storage medium mentioned above includes any medium capable of storing program code, such as a USB flash drive, removable hard disk, ROM, RAM, magnetic disk, or optical disk.

[0173] Units described as separate parts may or may not be physically separate, and parts represented as units may or may not be physical units, may be located in one location, or may be distributed across multiple network units. Some or all of the units may be selected based on actual requirements to achieve the objectives of the solutions of the embodiments. Furthermore, the functional units in the embodiments of this application may be integrated into a single processing unit, or each unit may exist physically independently, or two or more units may be integrated into a single unit.

[0174] The above description represents only specific embodiments of this application and is not intended to limit the scope of protection of this application. Any modifications or substitutions readily understood by those skilled in the art within the scope of the technical scope disclosed herein shall fall within the scope of protection of this application. Accordingly, the scope of protection of this application shall be subject to the scope of protection of the claims.

[0175] How to acquire spatial reference channels through online / offline training

[0176] Technical field This disclosure relates to wireless communications in general.

[0177] Acronyms and abbreviations

[0178]

Table 1

[0179] MIMO and MU - MIMO MIMO systems are widely deployed in modern wireless systems to improve system capacity and bandwidth efficiency by utilizing spatial diversity between antenna ports. For example, on a given sub - carrier or RE, a transceiver consisting of N Tx Tx antenna ports and N Rx Rx antenna ports can be decomposed via SVD[4] into an N Tx - by - N Rx complex matrix H UE,RE represented by an N Tx - by - N Rx MIMO channel, where H UE,RE = Z UE,RE S UE,RE V UE,RE H and here, Z UE,RE is an N Tx - by - N Tx square orthogonal matrix (satisfying Z UE,RE H Z UE,RE = I), V UE,RE is an N Rx - by - N Rx square orthogonal matrix (satisfying V UE,RE H V UE,RE = I), and S UE,RE is an N Tx - by - N Rx rectangular diagonal matrix. The rank (r UE,RE ) of H UE,RE is less than or equal to the smaller of N Rx and N Tx , that is, r UE,RE = min(N Tx , N Rx ). According to standard SVD, if the transmitter applies the precoder matrix Z UE,RE H and the receiver applies the receive matrix VUE,RE If applied, N Tx -by-N Rx MIMO channels are defined as follows: UE,RE This results in individual, independent, parallel (orthogonal) subchannels. Z UE,RE H H UE,RE V UE,RE =( Z UE,RE H Z UE,RE )S UE,RE (V UE,RE H V UE,RE )=S UE,RE

[0180] Each subchannel has a scaled channel response (H UE,RE (i)) that is, S UE,RE The i-th diagonal element (singular value, h) UE,RE (i) = S UE,RE It has (i,i). Therefore, the SNR on the i-th subchannel is

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[0181] SNR-based truncation MIMO decomposition transforms standard SVD into rank-reduced SVD by discarding subchannels with an SNR below a threshold (multiple thresholds are possible), i.e., H UE,RE ≒Z UE,RE S UE,RE V UE,RE H (The reduced SVD in [4]), where Z UE,RE is, N Tx -by-r UE,RE The orthonormal matrix of (Z UE,RE H Z UE,RE (satisfying I) and V UE,RE is, r UE,RE -by-N RxThe orthogonal matrix (V UE,RE H V UE,RE = I is satisfied), and S UE,RE is an r UE,RE -by-r UE,RE square diagonal matrix. The MIMO flow number of H UE,RE is r UE,RE ≦ min(N Tx , N Rx ). When the transmitter applies the precoder matrix Z UE,RE H and the corresponding receiver applies the receiving matrix V UE,RE [[ID=2�]] Tx -by-N Rx The MIMO channel becomes as follows. Z UE,RE H H UE,RE V UE,RE = (Z UE,RE H Z UE,RE ) S UE,RE (V UE,RE H V UE,RE ) = S UE,RE

[0182] In the rank reduction SVD, S UE,RE is an r UE,RE -by-r UE,RE diagonal matrix.

[0183] Mathematically speaking, the precoder matrix Z UE,RE at the transmitter and the receiving matrix V H at the receiver act multiplicatively on the entire MIMO channel on the effective subchannels by linear transformation over the MIMO channel H UE,RE UE,RE . The MIMO gain or spatial diversity gain is SNRs

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[0184] For higher MIMO gain, the wireless system has a number of antenna ports, i.e., N Tx and N Rx This increases r UE,RE ≤min(N) Tx ,N Rx ) Therefore, the upper limit on the number of potential MIMO flows is increased. However, in practice, r UE,RE Its upper limit min(N) Tx ,N Rx This is much smaller than ). This motivates the development of MU-MIMO, i.e., if one MIMO channel generates an insufficient number of MIMO flows, multiple MIMO channels can be multiplexed by a common precoder W. Two MIMO channels on the same RE, H UE(1),RE and H UE(2),RE Assuming they are very different from each other, it is likely that we will find a common precoder to multiplex (separate) both, but two MIMO channels on the same RE, H UE(1),RE and H UE(2),RE Assuming they are nearly identical, the likelihood of finding a common precoder to multiplex (separate) both is low.

[0185] Mathematically, this common precoder W is equivalent to precoder Z UE(1),RE and Z UE(2),RE Related to this. The method that is actually widely used is based on EZF. Two precoders from reduced SVD on a MIMO channel,

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[0186] After the common precoder W is calculated, the transmitter multiplies it by its transmission signal.

[0187] Trade-offs of MU-MIMO technology In the case of a wireless system, MU-MIMO is usually used in the DL, the BS is the transmitter, and the UE is the receiver. The MIMO channels of multiple UEs are paired by a common precoder W and multiplexed at the same RE (frequency) and the same duration (timing).

[0188] For higher throughput and system efficiency, modern MU-MIMO systems deploy a large number of antenna ports over a wider bandwidth. For example, in a (6G) T-MIMO system, it is expected that the BS has 1024 antenna ports and the UE has 32 antenna ports over a 500 MHz bandwidth. The MIMO channel becomes a three-dimensional tensor (N RE -by-N Tx -by-N Rx ).

[0189] FIG. 12 shows the dimensions of the TMIMO channel according to an embodiment of the present application.

[0190] Major Trade-off #1: Assumptions Regarding DL / UL Channel Reciprocity MU-MIMO should be paired on a DL channel between one BS and multiple UEs, but it is not feasible for each candidate UE to report or feed back its DL channel estimation to the BS, as this would result in enormous UL feedback overhead due to the large dimension of the T-MIMO channel. In a TDD system, it is assumed that the DL channel between one BS and one UE can be approximated by the UL channel between the BS and the UE. In 4G and 5G-NR systems, an SRS UL channel is designated for UL channel measurement or estimation for this purpose. The SRS UL channel is shared by a number of UEs. These UEs transmit their own SRS reference signals on the SRS pilot position so that the BS can estimate each of their UL MIMO channels. In 5G-NR, sharing is achieved by coded multiplexing on the modulated signal.

[0191] Major Trade-off - 2: Implementation Methods of Random or Pseudo-Random MU Pairing As mentioned above, MU pairing is an NP-hard problem. Theoretically, the optimal pairing is the result of exhaustive searching (computation) of all possible combinations of candidate UEs, from two to all of them. However, the pseudoinverse of a large matrix

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[0192] Strictly speaking, the trade-off is not about implementing pairing, but rather about the reversibility of either one.

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[0193] 5G-NR SRS UL and CSI-RS for acquiring DL MIMO channels 5G-NR uses SRS UL channels to measure the UL MIMO channel between the BS (as a transmitter) and multiple UEs (as receivers). The BS assumes the UL MIMO channel, measured or estimated from the SRS UL channel(s), as the DL MIMO channel between the BS and the UEs in TDD mode.

[0194] In detail, the SRS UL channel defines a set of uniform pilot (or reference signal) placement or position patterns with respect to RE (frequency), BS antenna port, and UE antenna port. The uniform pilot placement patterns are specified in the 5G-NR standard, to which both BS and UE must comply. One reason for standardizing uniform pilot placement patterns is their simplicity; only a few of the parameters are exchanged at both the transmitter and receiver to align the current pattern(s) to be used with one another.

[0195] Furthermore, to allow the BS to measure two or more UEs simultaneously, a coding multiplexing scheme is used on the pilot, enabling two or more UEs to share the same pilot location by masking their pilots with different codes. In 5G-NR, the coding multiplexing scheme on the SRS UL channel is designed to accommodate up to 16 UEs. If there are more than 16 UEs requesting to share the SRS UL channel, a new pilot location must be consumed. As a result, 5G-NR has the capacity for the SRS UL channel to measure several UEs simultaneously.

[0196] When the RF and IF portions are considered, UL / DL channels are not always reciprocal.

[0197] The received UL signal strength from the UE to the BS on the cell edge may be too weak to estimate. These UEs must feed back their DL MIMO channels instead of transmitting their pilots on the SRS UL channel. Therefore, 5G-NR provides a CSI-RS, a uniform pilot placement pattern, on the DL channel(s). The UE estimates the channel coefficients on the pilot (RS, reference signal) in the DL channel and then interpolates the entire channel coefficient from the estimates. The UE compresses the entire channel estimation into a CSI and then feeds it back to the BS on the UL channel. The 5G standard defines not only the pilot placement pattern(s) for CSI-RS on the DL channel, but also the compression method. For example, the CSI includes the PMI and RI, both of which are indices in some pre-configured table of precoding matrices and ranks. The BS is expected to reconstruct the CSI into a DL MIMO channel estimation and then perform subsequent MU-MIMO pairing and common precoder calculations. Generally, CSI-RS DL channels result in CSI compression for reconstruction purposes, and specifically, the CSI compression or encoder specified in 5G-NR is lossy compression.

[0198] MU-MIMO pairing and precoding matrix calculation using EZF As explained in the background technology section, pairing search and common precoder matrix calculation are performed together.

[0199] Firstly, the calculation of the common precoding matrix cannot be performed until all SVDs have been performed on the candidate UEs.

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[0200] Secondly,

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[0201] Non-uniform pilot placement patterns Both 5G-NR SRS UL channels and CSI-RS DL channels employ a uniform pilot placement pattern, partly because a uniform pilot placement pattern is one of the safest ways to guarantee channel estimation performance, especially with little prior knowledge of the current channels, and partly because they are easy to describe, standardize, and align (configure) across transceivers. However, a uniform pilot placement pattern is one of the least efficient patterns. Its density must be designed for the worst-case scenario in statistics, which is rare in practice. In other words, the uniform pilot placement pattern specified in the 5G-NR standard may be over-engineered in most real-world cases.

[0202] In 5G-NR, the average density of its uniform pilot placement pattern is approximately 7% to 17% of its radio resources used for pilot or reference signals. For example, one reference signal placed for each RB (consisting of 12 consecutive REs) results in 8.33% (approximately 1 / 12) of pilot overhead. As shown in Figure 12, if TMIMO were to adopt the same uniform density as 5G-NR, the pilot overhead would be too heavy to handle, or at least would prevent UEs on the cell edges from feeding back their T-MIMO CSI.

[0203] From prior knowledge representing a common-space basis (U), a nearly optimal non-uniform pilot placement pattern can be computed by pivot QRD[3]:UP=QR on U. Multiple "strongest" pivots in P (in a typical pivot QRD, the pivots are ordered in terms of their importance or contribution) indicate the most important or contributing positions for placing the reference signal (or pilot) for reconstruction purposes.

[0204] The non-uniform pilot placement pattern(s) indicated by the pivots within P results in nearly minimal pilot overhead, while still minimizing the MSE for reconfiguration (or decoder, restoration).

[0205] 5G-NR SRS UL and CSI-RS for acquiring DL MIMO channels The first major drawback stems from the assumption regarding UL / DL channel reciprocity. While the radio portion of a MIMO channel can typically satisfy UL / DL reciprocity thanks to information theory (I(X,Y)=I(Y,X), where I(X,Y) is the mutual information of two random variables X and Y), the RF and IF components (analog circuits) generally do not maintain the UL / DL reciprocity assumption. Consequently, this assumption inevitably impairs overall performance. Furthermore, this assumption holds only in TDD mode, not in FDD mode.

[0206] The second major drawback arises when the dimensionality of the MIMO channel becomes large, such as in T-MIMO in Figure 12. BS must estimate the total MIMO channel for all encoded multiplexing UEs on its SRS UL channel. Firstly, it must estimate the channel coefficients on all single pilots for each encoded multiplexing UE. Secondly, it must interpolate the entire MIMO channel from the estimated channel coefficients on pilots for each UE. Thirdly, it must attempt to pair all active UEs and compute their common precoder. The dimensionality of a typical T-MIMO makes memory and computation impossible.

[0207] A third major drawback is MAI between coding multiplexing UEs sharing the same SRS UL channel. MAI is unavoidable; on the one hand, it limits the maximum number of coding multiplexing UEs (capacity limit), and on the other hand, it impairs the accuracy (or performance) of channel estimation. This is why 5G-NR must limit the maximum number of UEs to share the same SRS UL channel. Nevertheless, the limited capacity on the SRS UL channel presents scheduling and overhead in 6G, where far more active UEs are accommodated by a single BS than in 5G-NR.

[0208] The fourth major drawback is due to mobility. It is well known that radio channels change significantly when the UE is moving. Sometimes, even small positional displacements cause LOS loss, leading to enormous channel changes. Because the SRS-UL channel is shared among all active UEs and the SRS-UL channel has a capacity cap, it is not easy for a large number of UEs and BSs to perform their SRS-UL channel estimations very frequently, and it consumes power. Thus, in practice, SRS-UL based MU-MIMO is very sensitive to mobility.

[0209] The final major drawback is the inclusion of DL CSI-RS channels for UEs on the cell edges. In fact, UEs on the cell edges using CSI-RS will suffer more severe performance losses.

[0210] MU-MIMO pairing and precoding matrix calculation using EZF The first drawback is that, even for any potential pairing attempt,

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[0211] The second drawback is that the widely used EZF method, for any potential pairing attempts,

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[0212] The final drawback is that the pairing and precoder calculations are sequential.

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[0213] QRD-based non-uniform pilot placement and compression This method provides a good channel estimation and compression mechanism with nearly minimal pilot and compression overhead, but it is still intended to reconstruct the channels as reliably as possible. This objective involves minimizing the overhead in the number of reference signals and the compression ratio, both of which require the minimum size of the common-space basis (U) in depth. From a source coding perspective, the common-space basis (U) is the codebook for minimizing the MSE in reconstruction. dim -by-r env How many of the r in U env Whether a column is preserved determines how much "detail" is reconstructed. A common-space basis (U) is the result of SVD[4], and since SVD typically orders the columns of U in descending order of their corresponding singular values, the first column of U is more important (more principal in mathematical terms) than the second column, and so on. More columns preserved in U provide more "detail" regarding the reconstruction, but these "details" are less important in terms of energy.

[0214] Overall MIMO channel (H UE,RE To reconstruct the BS and non-uniform pilot pattern (P), a sufficiently large common space basis (U) must be aligned between the BS and UE. Unfortunately, in the TMIMO scenario, both U and P are enormous in size. Furthermore, when the UE moves from one region to another, it must be updated from the current U and P as well as the new U and P.

[0215] Since a common-space basis (U) is learned from several data samples, the common-space basis (U) is itself a high IPR entity. Collecting and cleaning data samples, especially large-dimensional data samples, and computing the common-space basis (U) is costly. Anyone with a common-space basis (U) can optimize its non-uniform pilot pattern, and even its compression scheme.

[0216] 4. Detailed description of the technical solution of the present invention This invention focuses on how to achieve MU-MIMO pairing and precoder matrix computation in T-MIMO scenarios. Generally speaking, the invention includes how to estimate DL MIMO channels for moving UEs, how to select the best pair or group (more than two UEs) from all candidate combinations, and how to compute a common precoder matrix with reasonable storage and computational complexity.

[0217] As shown in Figure 12, a key problem arises from the enormous dimensions of T-MIMO, which present challenges at every step for feedback, storage, and computation.

[0218] More specifically, the following main problems are solved by the present invention.

[0219] 1) The method in this invention no longer makes the assumption of UL / DL channel reciprocity, and therefore there is no performance loss, it is not unfair to UEs on the cell edges, and furthermore, since the CSI-RS DL channel can be naturally shared simultaneously among an infinite number of UEs, it can ultimately support FDD-MU-MIMO.

[0220] 2) The UE estimates DL MIMO channels using CSI-RS DL channels with an extremely sparse, non-uniform pilot placement pattern, rather than 5G-NR CSI-RS DL channels with a uniform pilot placement pattern. The non-uniform pilot placement pattern of the present invention requires a pilot density several orders of magnitude lower than that of the uniform pilot placement pattern of 5G-NR.

[0221] 3) The UE can feed back highly compressed CSI to the BS while consuming several orders of magnitude less compression than 5G-NR's CSI compression.

[0222] 4) BS does not restore the CSI and continues to use the compressed CSI to complete all of the following operations, including SVD-based MIMO channel decomposition, EZF-based pairing, and precoder matrix calculation, thus saving a great deal of storage and computational complexity.

[0223] 5) Pairing and precoder matrix calculation can be separated, and furthermore, pairing or grouping can be performed before SVD channel decomposition, meaning that only selected UEs are notified to feed their compressed CSI back to BS for the final common precoder matrix calculation, thus achieving parallelism between pairing attempts and precoder calculations.

[0224] 6) Pairing can be simplified to support high mobility.

[0225] To address the challenges and problems discussed in the previous section, we will primarily rely on two fundamental principles: environment-dependent MIMO channels and equivalent low-dimensional signal spaces.

[0226] It is well known that the radio channel between a transmitter and a receiver is primarily governed by its environment. The inherent relationship between the environment and the radio channel is embodied in the RT channel model, which generates the channel response as a function of LOS and NLOS (reflection and / or spread), i.e., rays or clusters of rays, and some randomness. According to the RT channel model, the radio channel consists of a deterministic part due to RT and a probabilistic part due to random events. The deterministic part is several common properties between channels in a nearby region, which can be represented in a common orthonormal basis (U) that is learned and referred to as the basis in the following description. Any (vectorized) channel h can be represented by a weighted linear combination of columns of the basis U, where the weight coefficients are called the spectral coefficient vector c: h = Uc. A general orthonormal basis (U) is a thin and long matrix (N dim ≫r env ) However, the spectral coefficient vector c(r env -by-1) is h(N dim It is much smaller than (-by-1) and is mathematically an equivalent low-dimensional space of h. This allows some memory, representation, or computation for h to be performed equivalently on c, which is an equivalent low-dimensional signal space of h.

[0227] This IPR disclosure includes DL pilot placement patterns, channel estimation, and spatial reference channels.

[0228] In the following explanation, due to the high dimensionality of T-MIMO radio channels, as shown in Figure 12, we will use T-MIMO radio channels as an example and shorten them to radio channels or channels. It should be noted that spatial reference (anchoring) channels may be applicable to higher-dimensional signal spaces other than T-MIMO.

[0229] 1: Common prior knowledge regarding radio channels A radio channel, or multipath fading channel, is more or less affected by its surroundings because its radio path, radio waves, or clusters (or groups) of radio waves are physically involved in reflection and diffusion at physical surfaces, edges, or corners such as buildings, roads, buses, railway tracks, and people. Some surfaces, edges, and corners are stationary (e.g., buildings, bridges, pillars, roads, pavement, etc.), while others are moving (e.g., moving vehicles and pedestrians, etc.). Generally, stationary factors contribute to some deterministic part of the radio channel, while moving factors contribute to the stochastic part.

[0230] Up to 5G-NR, wireless systems treat both deterministic and probabilistic parts together as a single radio channel entity and do not assume prior knowledge about the radio channel. Therefore, the transceiver must consume both pilot and measurement feedback overhead to synchronously know what the current channel is.

[0231] Since most immovable factors stemming from the deterministic part of the radio channel are usually known in advance or available, this part of the radio channel can also be known in advance for both the transmitter and receiver, leaving only the stochastic part for pilot and measurement feedback overhead, and dramatically increasing effective bandwidth efficiency. In most practical cases where the deterministic part of the radio channel dominates the radio channel more persistently and consistently than the stochastic part, acquiring prior knowledge about the radio channel is valuable and important, and this can be expressed in various forms: - Alternative form #1: Statistical functions or functions with arguments; - Alternative form #2: One or more orthonormal bases; - Alternative form #3: One or more DNNs; - The same applies below.

[0232] While it is possible to learn or acquire prior knowledge of a specific radio channel between a single transmitter and receiver, in the context of cellular communications, it is more useful to learn or acquire common prior knowledge covering several similar radio channels within a particular spatial domain. By doing so, the acquired prior knowledge is shared and reused among any new radio channels within that spatial domain. In this sense, the acquired prior knowledge represents spatial commonality closely related to that spatial domain. A BS, either as a transmitter or a receiver, can have one or more common prior knowledge relating to one or more overlapping or non-overlapping spatial domains. Furthermore, since different bands correspond to different wavelengths, a BS may have one prior knowledge representation for one band and another prior knowledge representation for another band.

[0233] - Alternative form #1: BS has one common prior knowledge; - Alternative form #2: The BS has multiple sectors, each of which has its own common prior knowledge, and these sectors may or may not overlap; - Alternative form #3: The BS has one common prior knowledge, but has multiple sectors, each of which has its own common prior knowledge, and these sectors may or may not overlap; -Alternative form #4: BS has multiple pre-installed Tx precoders, each of which has its own common prior knowledge; -Alternative form #5: BS may have one piece of prior knowledge specific to one of its associated UEs, which may be useful for some fixed UEs; - The same applies below.

[0234] 2: Preparation of data samples for learning or acquiring common prior knowledge about radio channels. The common spatial prior knowledge related to a given spatial domain proposed in 1 is acquired or learned from data samples prepared in the following various ways.

[0235] Alternative form #1: Common prior knowledge is acquired or learned from a set of data samples, a learning dataset, or a training dataset accumulated in the history by either the transmitter or the receiver, and initially, the BS, as a transmitter without prior knowledge, must utilize some conventional technique methods such as SRS sounding and / or CSI-RS to accumulate a sufficient amount of radio channel data samples from which common prior knowledge is learned.

[0236] Alternative form #2: Common prior knowledge is acquired or learned from a set of data samples, training datasets, or development datasets fed back by several reference units (reference UEs or sensing UEs) deployed as receivers within the domain, and their DL estimated radio channels are fed back to the BS as transmitters to accumulate a sufficient amount of radio channel data samples for common prior knowledge to be learned.

[0237] Alternative form #3: Common prior knowledge is acquired or learned from a sample dataset, training dataset, or development dataset virtually generated by the digital twin, and the digital twin generates virtual data samples depending on the 3D map / model or other environment-related information.

[0238] Alternative Form #4: Common prior knowledge is acquired or learned from a sample dataset, training dataset, or development dataset, which is a combination result of Alternative Forms #2 and #3. First, the digital twin generates an initial data sample set for the initial prior knowledge. Then, the initial prior knowledge triggers a first actual measurement and feedback on the deployed sensing UE. The first measurement then partially replaces some samples in the data sample set with a second data sample set for refined second prior knowledge. The refined prior knowledge triggers a second actual measurement, and so on.

[0239] Alternative Form #5: Common prior knowledge is obtained or learned from a sample dataset, training dataset, or development dataset which is a combination of Alternative Forms #1, #2, and #3. First, historical data and digital twins generate an initial data sample set for initial prior knowledge. Then, the initial prior knowledge triggers a first actual measurement and feedback to the deployed sensing UE. The first measurement then partially replaces some samples in the data sample set with a second data sample set for refined second prior knowledge. The refined prior knowledge triggers a second actual measurement, and so on.

[0240] 3: Representation and learning / acquisition of common prior knowledge based on orthonormal bases (unitary matrices) The common spatial prior knowledge related to a given spatial domain, as proposed in 1, can be represented in different forms: statistical-based, basis (unitary matrix)-based, and DNN-based. In fact, prior art wireless systems have used statistical functions or equations to calculate important statistics about radio channels, such as coherent time, coherent frequency, and RMS delay. The basis-based and DNN-based representations are obtained from the data samples prepared in 2. Generally, the basis-based representation is linear, while the DNN-based representation is a nonlinear approximation of the basis-based representation. This embodiment focuses on a method for learning or obtaining a basis-based representation of common prior knowledge of radio channels related to a particular spatial domain.

[0241] MIMO wireless channels use a 3D tensor:N RE -by-N Tx -by-N Rx This is H. This must be vectorized for matrix-based decomposition, as shown in Figure 13.

[0242] Figure 13 shows a vectorization of a tensor MIMO channel sample according to one embodiment of this application.

[0243] If all MIMO radio channel samples are vectorized in the same dimensional order, the order itself is not very important for subsequent learning performance. In this IPR, the first MIMO radio channel data sample in the tensor is N RE -by-N Tx -by-N Rx H1 is H1, and in the order RE->Tx->Rx, h1(N dim -by-1, N dim =N RE N Tx N Rx ), vectorized into the first column vector, the second MIMO radio channel data samples in the tensor are N RE -by-N Tx -by-N Rx And in the same order h2(N dim -by-1, N dim =N RE N Tx N Rx ), then vectorized into a second column vector, and so on until all M MIMO radio channel samples in the tensor are vectorized.

[0244] A sufficient number (N dim ≫M>r env The vectorized MIMO radio channel samples satisfying M) are N dim -by-M matrix

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[0245] (Note that in the above deduction, h is set as a column vector. Without loss of generality, if we set h as a row vector,

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[0246] Using the basis (U), each vectorized channel data sample h is expressed as a spectral coefficient: c=U H It can be projected (compressed or encoded) into an equivalent low-dimensional space named h, where c is r env It is a -by-1 vector. The spectral coefficient representation can be backprojected (restored or decoded) onto the original channel data space: h=Uc, so c contains all the major information of h.

[0247] 4: Representation and learning / acquisition of common prior knowledge based on DNNs The DNN-based representation of prior knowledge in 2 is an approximation t for the linear basis (U) in 2. The encoded DNN (c=f(h;α)) is c=U in 3. H By approximating h, the decoded DNN (h=g(c;β)) approximates h=Uc in 3. The output of the latent layer (c=f(h;α)) approaches an equivalent low-dimensional space, i.e., the spectral coefficient representation of 3.

[0248] MSE

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[0249] 5: Scoring the distance between any two wireless channels According to the mathematical properties of SVD, the basis U of 3 represents common (spatial) prior knowledge of all radio channels related to a particular spatial domain. Any new MIMO radio channel (h user )(N dim -by-1, N dim =N RE N Tx N Rx ) is h user =Uc user and c user =U H h user A basis (U) satisfying the above conditions results in a lower-dimensional space, i.e., a spectral coefficient vector (c user )(r env It can be safely projected to -by-1).

[0250] The basis U is any two radio channels (h) in the equivalent low-dimensional space. user1 and h user2 It enables scoring or measuring the "distance (similarity, correlation, etc.)" metric between two wireless channels (h user1 and h user2 A scoring or measurement function δ that returns the "distance," "similarity," or "correlation" between ) 1,2 =d(h user1 ,h user2 This shows that if d() is linear, then δ 1,2 =d(h user1 ,h user2 )=d(Uc user1 ,Uc user2 )=Ud(c user1 ,c user2 This means that scoring or measurement can be performed equivalently in a low-dimensional spectral space. The scoring or measurement function d() can be linear and simple. - Alternative form #1: Euclidean function, - Alternative form #2: Inner product, - The same applies below.

[0251] In the case of the DNN-based representation in 4, the scoring or measurement function for the latent layer output is a different DNN(δ 1,2 =d(c user1 ,c user2 ,γ)), where γ is a neuron.

[0252] 6. Generation and alignment of pilot placement patterns and feedback spectral coefficients The basis U in 3 represents common (spatial) prior knowledge of all radio channels associated with a particular spatial domain. Arbitrary new MIMO radio channel estimation

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[0253] Pilot for channel estimation Channel estimation for the stochastic part of a wireless channel 1

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[0254] - Alternative form #1: By a legacy uniform pilot placement pattern. For example, in the 5G-NR specification, all RBs have one pilot, the pilot is always positioned across the RB direction, and both the transmitter and receiver are specified to conform to 3GPP® standards.

[0255] -Alternative form #2: Pilot positions are generated by a pseudo-random pilot placement pattern using a function of random seeds; the pattern function and random seeds must be explicitly or implicitly aligned across the transmitter and receiver;

[0256] - Alternative form #3: By pilot placement pattern in a function of basis U; one exemplary way of approaching the optimal pattern is disclosed in [1] (with an extended version for MIMO) and [2] (without an extended version), where either the generating function or basis U is explicitly or implicitly aligned across the transmitter and receiver, or the generated pattern is explicitly or implicitly aligned across the transmitter and receiver.

[0257] -Alternative form #4: The pilot placement pattern output from the generating DNN explicitly or implicitly aligns the generating DNN and its inputs across the transmitter and receiver, or the generated pattern explicitly or implicitly aligns across the transmitter and receiver.

[0258] - The same applies below.

[0259] In either generation method, the pilot placement pattern is N pilot -by-N dim The sampling (position or arrangement) matrix P can be represented by a sampling matrix P, where each row has only one "1" to indicate a position to be used as a pilot, and the BS as the transmitter transmits pilots at these positions indicated by the sampling matrix P, and the UE(s) as the receiver(s) transmit channel coefficients at these positions indicated by the same sampling matrix P.

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[0260] Therefore, in order to align the pilot placement scheme across the transmitter and receiver, the system -Alternative form #1: Using a predefined standard protocol similar to 5G-NR, -Alternative form #2: Random seeds and standardized methods or generation functions for random seeds, -Alternative form #3: If U is available on both sides, the generating function from the basis U can be used. -Alternative form #4: Generative DNN and its input, -Alternative form #4: This can be done by directly transmitting the pilot placement matrix (or scheme) as the payload.

[0261] Channel estimation feedback Even more interestingly, using the sampling matrix P, and setting θ = PU, we have the basis U(N dim -by-r env ) to N pilot -by-r env It can be "compressed" to θ. θ is much smaller than U (N pilot ≪N dim (Therefore) since no one can reconstruct the basis U from θ, θ can be a better alternative form of U. Furthermore, the receiver is given the spectral coefficient vector by θ.

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[0262] If the basis is approached by a DNN, both the transmitter and receiver should be aligned with f(α) and g(β) of 4.

[0263] To minimize pilot and feedback overhead, both the transmitter and receiver use a random seed, a pseudo-randomly generated pilot placement function, and θ(θ) H θ) -1 They should be aligned by: In the T-MIMO scenario, the BS as the transmitter has a random seed and θ(θ) in the DL as the control payload. H θ) -1 The common pilot placement scheme is broadcast or multicast, and pilots are transmitted according to the common pilot placement scheme. Candidate UEs as receivers use the common pilot placement scheme and θ(θ H θ) -1 The system acquires the data, demodulates the pilot according to the pilot placement scheme, estimates the channel coefficients for the pilot, and calculates the spectral coefficients with respect to the channel estimation for the pilot. Optionally, immediately after acquiring the spectral coefficients, the UE can feed the spectral coefficients back to the BS via the UL as a control payload.

[0264] Figure 6. Exemplary Procedure 7: Selection of a (Spatial) Reference (Anchoring) Channel A set of K (K ≤ M) wireless channels is selected from M training data samples, and 2 and 3

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[0265] Figure 14: Hubs in the graph are the most representative nodes.

[0266] In either selection method, K radio channel samples constitute a set of spatial reference (anchoring) channels, i.e.,

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[0267] In the following explanation, we will focus on a single set of spatial reference channels, since a single set can easily be extended to multiple sets, unless explicitly stated otherwise.

[0268] 8: Compression of spatial reference channels and transmission to the UE Reference channel

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[0269] According to Equation 3, the radio channel is given by the spectral coefficient vector c Set(k) =U H h Set(k) It can be equivalently projected (compressed or encoded) onto k=1,2,...,K. This projection is the set of spatial reference channels in 7.

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[0270] Preferably, the BS, as the transmitter, broadcasts, multicasts, or unicasts via the DL to its UE, as the receiver, a complete or partial set of compressed spatial reference channels.

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[0271] Compressed basis U TMIMO's N dim (h Set(k) (Both dimensions of and U) BS or UE are all

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[0272] MU-MIMO pairing is performed on an RBG basis, and one MU-MIMO pairing scheme and its precoder matrix have an average of N values ​​across RBGs containing multiple consecutive RBs (each RB has 12 REs). Tx -by-N Rx It is found on MIMO channels. Firstly, h Set(k) , 3:H Set(k) =tensorize(h Set(k) ) According to the dimensional order, its tensor form is, i.e., N RE -by-N Tx -by-N Rx H Set(k) It can be sorted from the first RE to N RE Up to the second RE, each RE is N Tx -by-N Rx H Set(k),RE (=H Set(k) [RE,:,:]) MIMO channel has first N RBG If RE constitutes the first RBG, then N on the first RBG Tx -by-N Rx MIMO channels are the first N RBG

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[0273] h Set(k) c is the spectral coefficient vector Set(k) Since it can be expressed as a linear combination of a sequence of basis U,

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[0274]

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[0275] Furthermore, H Set(k),RBG-l is, N Tx -by-N Rx The orthonormal projection matrix Q Set(k),RBG-l and N Rx -by-N RxUpper triangular square matrix R Set(k),RBG-l :H Set(k),RBG-l =Q Set(k),RBG-l R Set(k),RBG-l It can be converted to QRD. Projection matrix Q Set(k),RBG-l Using

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[0276] The present invention can be used to solve pilot design problems for T-MIMO systems with a large number of antenna ports on the transmitter and receiver and a large bandwidth. The same method can also be applied to conventional MIMO systems (e.g., 5G MIMO systems) or single-antenna systems.

[0277] By using this invention, the following characters will appear in the system.

[0278] Prior knowledge of the target environment's channel status is required. This means the system obtains the target environment's channel space basis (U) or a similar channel status-related representation. Thanks to prior knowledge of the target environment's channel status, pilot usage or overhead can be saved.

[0279] The pilot patterns are far more sparse than conventional pilot patterns (5G NR pilot designs) and can be non-uniformly distributed along time-frequency-spatial resources.

[0280] Novel Methods / Procedures for Acquiring Mooring Channels through Online / Offline Training for Large-Scale MIMO Wireless Communications • Pre-define a dedicated time window in the specification for spatial reference channel training. • Multiple RS transmission opportunities may be assumed by BS and UE. • The BS configures time, frequency, and spatial resources to obtain a spatial reference channel on the BS and / or UE side. Alternative form 1: The BS configures a UL reference signal to one or more UEs in order to acquire a spatial reference channel on the BS side. Alternative form 2: The BS receives the DL RS and configures a DL reference signal to one or more UEs to obtain a spatial reference channel on the UE side. Furthermore, based on the configuration, the UE can feed back information about the acquired spatial reference channel to the BS. • Alternative form 3: BS configures a sensing signal resource for one or more UEs to perform channel sensing, and the spatial reference channel is obtained on the UE side (e.g., monostatic sensing on the UE side). • BS and / or UE identify a set of spatial reference channels. The BS and / or UE monitor the performance of the set of spatial reference channels, e.g., communication-related performance (BLER, CQI, etc.) and intermediate performance metrics (distance or similarity of observed channels in the environment). • BS and / or UE start when an update of the spatial reference channel is required.

[0281] Figure 15: Embodiment 1 Figure 16: Embodiment 2 Figure 17: Embodiment 3 Figure 18: Embodiment 4

[0282] [1] PCT / CN2022 / 126878 A Method And Apparatus of Channel Estimation for MIMO System [2] PCT / CN2022 / 094688 An Method to Design Transmission Dimensionality and Reference Signal Placement Scheme for a Dimensional Transmission Channel by its Prior Structures [3] Pivot-QRD:https: / / en.wikipedia.org / wiki / QR_decomposition [4] SVD:https: / / en.wikipedia.org / wiki / QR_decomposition [5] Pseudo-Inverse:https: / / en.wikipedia.org / wiki / Moore%E2%80%93Penrose_inverse [6] MSE:https: / / en.wikipedia.org / wiki / Mean_squared_error [7] Condition number of matrix:https: / / en.wikipedia.org / wiki / Condition_number

[0283] 6G slingshots 2.3 6G Infrastructure Network One or more steps of the methods of the embodiments provided herein may be performed by corresponding units or modules, as shown in Figure 19. Figure 19 shows units or modules in a device such as ED 110, T-TRP 170, or NT-TRP 172. For example, a signal may be transmitted by a transmitting unit or transmitting module. For example, a signal may be transmitted by a transmitting unit or transmitting 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 modules are implemented, for example, using software for execution by a processor, they may be read by the processor individually or together, as needed, in single or multiple instances, for processing, and the modules themselves may contain instructions for further deployment and instantiation.

[0284] Further details regarding ED 110, T-TRP 170, and NT-TRP 172 are known to those skilled in the art; therefore, these details are omitted here.

[0285] A non-exhaustive list of possible units or configurable parameters, or of some embodiments of a MIMO system, includes:

[0286] Panel: A unit of antenna group, antenna array, or antenna sub-array capable of independently controlling the Tx or Rx beam.

[0287] Beams: Beams can be formed by performing amplitude and / or phase weighting on data transmitted or received by at least one antenna port, or by using another method, for example, by adjusting relevant parameters of the antenna unit. Beams may include Tx beams and / or Rx beams. The transmit beam shows the distribution of signal intensity formed in different directions in space after the signal has been transmitted through the antenna. The receive beam shows the distribution of signal intensity in different directions in space of the wireless signal received from the antenna. Beam information may also be a beam identifier, or an antenna port(s) identifier, or a CSI-RS resource identifier, or an SSB resource identifier, or an SRS resource identifier, or another reference signal resource identifier. [Explanation of Symbols]

[0288] 10. Communication equipment 11 Receiver Module 12 Processing Modules 13 Transmitter Module 20 Communication equipment 21 Transceivers 22 processors 23 memory 100 Communication Systems 110 Communication Electrical Devices 110a~110j Communication Electrical Devices (ED) 120 Wireless Access Networks 120a~120b Wireless Access Network (RAN) 120c Non-terrestrial communications network 130 Core Network 140 Public Switched Telephone Network (PSTN) 150 Internet 160 Other Networks 170a, 170b network nodes 170a~170b Base station (BS) 172 Non-terrestrial transmission / reception points (NT-TRP) 190a Air Interface 190b Air Interface 190c Air Interface 201 Transmitter 203 Receiver 208 memory 210 processors 252 Transmitter 253 Scheduler 254 Receiver 258 memory 260 processors 272 Transmitter 274 Receiver 276 processors 278 memory 280 antennas

Claims

1. A method for communication, Steps include: obtaining M channel data samples within a time window, wherein the M channel data samples are related to an environment parameter set, and M is a positive integer; A step of determining K reference channels (multiple channels are possible) based on the M channel data samples, wherein K ≥ 1 and K is an integer. Methods that include...

2. The aforementioned method, Steps to estimate the downlink (DL) channel between the transmitting device and the receiving device based on the K(or more) reference channels. The method according to claim 1, further comprising:

3. The method according to claim 1 or 2, wherein the time window is predefined or configured.

4. The aforementioned method, Step 1: Receiving configuration information of the DL signal used to determine the M channel data samples. It further includes, In the aforementioned time window, the step of determining the M channel data samples is: In the aforementioned time window, the step of determining the M channel data samples based on the DL signal. The method according to any one of claims 1 to 3, including the method described in any one of claims 1 to 3.

5. The aforementioned method, Step 1: Transmit configuration information of the detection signal used to determine the M channel data samples. It further includes, In the aforementioned time window, the step of determining the M channel data samples is: In the aforementioned time window, the step of determining the M channel data samples based on the echo signal corresponding to the detection signal. The method according to any one of claims 1 to 3, including the method described in any one of claims 1 to 3.

6. The aforementioned method, Step to transmit a detection signal It further includes, In the aforementioned time window, the step of determining the M channel data samples is: In the aforementioned time window, the step of determining the M channel data samples based on the echo signal corresponding to the detection signal. The method according to any one of claims 1 to 3, including the method described in any one of claims 1 to 3.

7. The aforementioned method, The step of transmitting configuration information of the uplink (UL) signal used to determine the M channel data samples. It further includes, In the aforementioned time window, the step of determining the M channel data samples is: In the aforementioned time window, the step of determining the M channel data samples based on the UL signal. The method according to any one of claims 1 to 3, including the method described in any one of claims 1 to 3.

8. The step of estimating the DL channel between the transmitting device and the receiving device based on the K(or more) reference channels is: A step of determining one or more first reference channels from the K reference channels, wherein the distance between the first reference channel and the DL channel is less than or equal to a threshold. The method according to any one of claims 2 to 7, further comprising:

9. The aforementioned method, A step of monitoring the performance of the one or more first reference channels in order to determine whether the one or more first reference channels need to be updated, wherein the performance includes communication-related performance or intermediate performance. The method according to claim 8, further comprising:

10. The aforementioned method, If one or more of the aforementioned reference channels need to be updated, the step of starting to update one or more of the aforementioned first reference channels. The method according to claim 9, further comprising:

11. A communication device comprising a processor, the processor configured to execute one or more instructions stored in memory, enabling the communication device to implement the method according to any one of claims 1 to 10.

12. The communication device according to claim 11, further comprising the memory.

13. The communication device according to claim 11 or 12, wherein the communication device includes a communication interface, and the communication interface is configured to input and / or output information or data.

14. A communication device comprising a function or unit for performing the method described in any one of claims 1 to 10.

15. A communication device comprising a circuit and a communication interface, wherein the communication interface is configured to receive information and / or data processed by the circuit and to transmit the information and / or data to the circuit, and the circuit is configured to perform the method according to any one of claims 1 to 10.

16. The communication device according to claim 15, wherein the communication interface is further configured to output information and / or data processed by the circuit.

17. A communication system comprising a transmitting device and a receiving device, wherein the receiving device performs the method described in any one of claims 1 to 10.

18. A computer-readable storage medium comprising one or more instructions, wherein when the one or more instructions are executed on a computer, the computer performs the method according to any one of claims 1 to 10.

19. A computer program product comprising one or more instructions, wherein when the one or more instructions are executed on a computer, the computer performs the method according to any one of claims 1 to 10.

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