Improving Network Multiple-Input Multiple-Output (MIMO) Performance with High Doppler Drift

Abstract

The present disclosure relates to techniques for performing wireless communication by a network communicating with a UE that is moving at high speed. The network may adapt the communication technique in response to the movement of the UE. For example, reference signals may be transmitted to the UE from additional transmission and reception points and / or using different configurations.

Description

Technical Field

[0001] This application relates to wireless communication, including communication processes for adapting base stations and network elements in a wireless communication system for rapidly moving user equipment devices. Background Art

[0002] The use of wireless communication systems is growing rapidly. Additionally, wireless communication technology has evolved from voice-only communication to also include the transmission of data such as Internet and multimedia content.

[0003] Mobile electronic devices can take the form of smart phones or tablets that users typically carry. Wearable devices (also known as accessory devices) are a newer form of mobile electronic device, one example being a smart watch. Additionally, low-cost, low-complexity wireless devices intended for static or dynamic deployment are also increasing rapidly as part of the development of the "Internet of Things". In other words, the range of complexities, capabilities, traffic patterns, and other characteristics of the required devices is becoming increasingly broad. Generally speaking, it is desirable to recognize and provide improved support for a wide range of required wireless communication characteristics. One characteristic could be, for example, the rapid movement of electronic devices on high-speed trains or other forms of rapid transportation. Therefore, improvements in this field are desired. Summary of the Invention

[0004] Embodiments of systems, apparatuses, and methods are presented herein for performing radio resource control connection procedures for rapidly moving wireless devices in a wireless communication system.

[0005] As described above, the number of use cases for communicating with wireless networks of different types of user equipment devices (UEs) with widely varying capabilities and usage expectations is increasing. One expansion direction of the possible use cases supported by wireless communication technology can include increasing the use of wireless networks by rapidly moving UEs. Wireless communication can be affected by rapid movement, including being affected by different channel characteristics observed by different transmission and reception points (TRPs) (e.g., along the route of a rapidly moving UE). For example, a UE moving along a high-speed train route may experience / exhibit different characteristics relative to TRPs before and after the UE.

[0006] Therefore, the techniques described herein include techniques for a network (e.g., communicating with a rapidly moving UE) to adapt communication technology to such rapid movement. For example, the network can schedule reference signals from multiple TRPs for use by the UE to demodulate data and / or control signals from the TRP. In another example, the network can use more flexible signaling to update the reference signal configuration. In another example, spatial relationships and / or the quasi-co-location concept and procedures can be adapted to support rapidly moving UEs. Different transmission configurations can be used by different TRPs, and the transmission configuration can be signaled flexibly.

[0007] In addition, the definition of spatial relation can be extended to include frequency offset. The network can configure the UE to transmit reference signals based on spatial relation and / or based on absolute channel number / frequency.

[0008] In addition, new operation modes can be created to support such fast movement. For example, the new mode can be a type of single downlink control information (DCI) multi-TRP mode. The new mode can include using multiple transmission configurations.

[0009] The techniques described herein can be implemented in and / or used with multiple different types of devices, including but not limited to mobile phones or smartphones (e.g., iPhone TM , Android TM -based phones), tablets (e.g., iPad TM , Samsung Galaxy TM ), portable game devices (e.g., Nintendo DS TM , PlayStation Portable TM , Gameboy Advance TM , iPhone TM ), wearable devices (e.g., smart watches, smart glasses), laptops, PDAs, portable Internet devices, music players, data storage devices, other handheld devices, vehicles, automobiles, unmanned aerial vehicles (e.g., drones) and unmanned flight controllers, other cellular network infrastructure equipment, servers, and any of a variety of other computing devices.

[0010] This summary is intended to provide a brief overview of some of the subject matter described in this document. Accordingly, it should be understood that the above features are merely examples and should not be construed as in any way narrowing the scope or essence of the subject matter described herein. Other features, aspects, and advantages of the subject matter described herein will become apparent from the following detailed description, the drawings, and the claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] A better understanding of the subject matter can be obtained when considering the following detailed description of the embodiments in conjunction with the drawings.

[0012] Figure 1 An exemplary wireless communication system including an accessory device is shown in accordance with some embodiments;

[0013] Figure 2 An exemplary wireless communication system in which two wireless devices are capable of performing direct device-to-device communication is shown in accordance with some embodiments;

[0014] Figure 3 is a block diagram showing an example wireless device according to some embodiments;

[0015] Figure 4 is a block diagram showing an exemplary base station according to some embodiments;

[0016] Figure 5 is a communication flowchart showing an exemplary method for performing communication in the case of a fast - moving UE; and

[0017] Figures 6 to 16 shows aspects of performing communication in the case of a fast - moving UE according to some embodiments.

[0018] Although the features described herein are susceptible to various modifications and alternative forms, specific embodiments thereof are shown by way of example in the drawings and are described in detail herein. However, it should be understood that the drawings and the detailed description thereof are not intended to limit the present disclosure to the specific forms disclosed, but on the contrary, are intended to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the subject matter as defined by the appended claims. Detailed Description

[0019] Acronyms and Abbreviations

[0020] The following acronyms and abbreviations are used in this disclosure:

[0021] 3GPP: 3rd Generation Partnership Project

[0022] 3GPP2: 3rd Generation Partnership Project 2

[0023] GSM: Global System for Mobile Communications

[0024] UMTS: Universal Mobile Telecommunications System

[0025] LTE: Long Term Evolution

[0026] IoT: Internet of Things

[0027] QCL: Quasi - Co - Located

[0028] TCI: Transmission Configuration Indication

[0029] RRC: Radio Resource Control

[0030] MAC: Medium Access Control

[0031] CE: Control Element

[0032] Tx: Transmit (or Transmission)

[0033] Rx: Receive

[0034] RS: Reference Signal

[0035] CSI: Channel State Information

[0036] Term

[0037] The following are definitions of terms used in this disclosure:

[0038] Memory medium - any of various types of non-transitory memory devices or storage devices. The term "memory medium" is intended to include installation media such as CD-ROMs, floppy disks, or magnetic tape devices; computer system memory or random access memory such as DRAM, DDR RAM, SRAM, EDO RAM, Rambus RAM, etc.; non-volatile memory such as flash memory, magnetic media such as hard disk drives or optical storage devices; registers, or other similar types of memory elements, etc. The memory medium may also include other types of non-transitory memory or combinations thereof. In addition, the memory medium may be located in a first computer system that executes a program, or may be located in a different second computer system that is connected to the first computer system via a network such as the Internet. In the latter case, the second computer system may provide program instructions to the first computer for execution. The term "memory medium" may include two or more memory media that may reside at different locations in different computer systems connected, for example, via a network. The memory medium may store program instructions (e.g., embodied as a computer program) executable by one or more processors.

[0039] Carrier medium - the memory medium as described above, and physical transmission media such as buses, networks, and / or other physical transmission media that convey signals such as electrical, electromagnetic, or digital signals.

[0040] Programmable hardware element - includes various hardware devices that include multiple programmable functional blocks connected via programmable interconnects. Examples include FPGAs (Field Programmable Gate Arrays), PLDs (Programmable Logic Devices), FPOAs (Field Programmable Object Arrays), and CPLDs (Complex PLDs). The programmable functional blocks can vary from fine-grained (combinational logic components or look-up tables) to coarse-grained (arithmetic logic units or processor cores). Programmable hardware elements may also be referred to as "configurable logic components".

[0041] Computer system - Any of various types of computing or processing systems, including personal computer systems (PCs), mainframe computer systems, workstations, network appliances, Internet appliances, personal digital assistants (PDAs), television systems, grid computing systems, or other devices or combinations of devices. Generally speaking, the term "computer system" can be broadly defined to cover any device (or combination of devices) having at least one processor that executes instructions from a memory medium.

[0042] User Equipment (UE) (or "UE device") - Any of various types of computer systems or devices that are mobile or portable and perform wireless communication. Examples of UE devices include mobile phones or smartphones (e.g., iPhone TM , Android TN -based phones), tablets (e.g., iPad TM , Samsung Galaxy TM ), portable gaming devices (e.g., Nintendo DS TM , PlayStation Portable TM , Gameboy Advance TM , iPhone TM ), wearable devices (e.g., smartwatches, smart glasses), laptop computers, PDAs, portable Internet devices, music players, data storage devices, other handheld devices, vehicles, automobiles, unmanned aerial vehicles (e.g., drones), and unmanned flight controllers, etc. Generally speaking, the term "UE" or "UE device" can be broadly defined to cover any electronic device, computing device, and / or telecommunications device (or combination of these devices) that is easily transportable by a user and capable of performing wireless communication.

[0043] Wireless device - Any of various types of computer systems or devices that perform wireless communication. A wireless device can be portable (or mobile), or it can be stationary or fixed in a certain location. A UE is an example of a wireless device.

[0044] Communication device - Any of various types of computer systems or devices that perform communication, where the communication can be wired or wireless. A communication device can be portable (or mobile), or it can be stationary or fixed in a certain location. A wireless device is an example of a communication device. A UE is another example of a communication device.

[0045] Base station - The term "base station" has the full scope of its ordinary meaning and includes at least a wireless communication station that is installed at a fixed location and used for communication as part of a wireless communication system.

[0046] Link budget limited - includes the full scope of its ordinary meaning and at least includes the characteristics of a wireless device (e.g., UE) that exhibits limited communication capabilities or limited power relative to a device that is not link budget limited or relative to a device for which a radio access technology (RAT) standard has been developed. A link budget limited wireless device may suffer from relatively limited receiving and / or transmitting capabilities, which may be due to one or more factors such as device design, device size, battery size, antenna size or design, transmit power, receive power, current transmission medium conditions, and / or other factors. Such a device may be referred to herein as a "link budget limited" (or "link budget constrained") device. Due to the size of the device, battery power, and / or transmit / receive power, the device may be inherently link budget limited. For example, a smartwatch communicating with a base station via LTE or LTE-A may be inherently link budget limited due to its reduced transmit / receive power and / or reduced antenna. Wearable devices such as smartwatches are generally link budget limited devices. Alternatively, the device may not be inherently link budget limited, for example, it may have sufficient size, battery power, and / or transmit / receive power for normal communication via LTE or LTE-A, but may be temporarily link budget limited due to current communication conditions, such as a smartphone at the cell edge, etc. It should be noted that the term "link budget limited" includes or encompasses power limitations, and thus a link limited device may be considered a link budget limited device.

[0047] Processing element (or processor) – refers to various elements or combinations of elements capable of performing functions in a device (e.g., a user equipment device or a cellular network device). Processing elements may include, for example: a processor and associated memory, portions or circuits of individual processor cores, entire processor cores, separate processors, processor arrays, circuits such as ASICs (application specific integrated circuits), programmable hardware elements such as field programmable gate arrays (FPGAs), and any of the various combinations above.

[0048] Automatically - means that an action or operation is performed by a computer system (e.g., software executed by a computer system) or a device (e.g., a circuit, a programmable hardware element, an ASIC, etc.) without the action or operation being directly specified or performed through user input. Thus, the term "automatically" is contrary to an operation being performed or specified manually by a user, where the user provides input to directly perform the operation. An automatic process can be initiated by input provided by the user, but the subsequent actions that are "automatically" performed are not specified by the user, i.e., they are not "manually" performed, where the user specifies each action to be performed. For example, a user filling out a spreadsheet by selecting each field and providing input to specify information (e.g., by typing information, selecting checkboxes, radio selections, etc.) is manually filling out the form, even though the computer system must update the form in response to the user's actions. The form can be filled out automatically by a computer system, where the computer system (e.g., software executed on a computer system) analyzes the fields of the form and fills out the form without any user input specifying the answers to the fields. As indicated above, the user can initiate the automatic filling of the form but does not participate in the actual filling of the form (e.g., the user does not manually specify the answers to the fields but they are completed automatically). This specification provides various examples of operations that are automatically performed in response to actions taken by the user.

[0049] Configured to - various components can be described as "configured to" perform one or more tasks. In such an environment, "configured to" is a broad statement generally meaning "having" the "structure" to perform one or more tasks during operation. Thus, even when the component is not currently performing a task, the component can be configured to perform the task (e.g., a set of electrical conductors can be configured to electrically connect a module to another module even when the two modules are not connected). In some contexts, "configured to" can be a broad statement generally meaning "having" the "circuitry" to perform one or more tasks during operation. Thus, even when the component is not currently powered on, the component can be configured to perform the task. Generally, the circuitry that forms the structure corresponding to "configured to" can include hardware circuitry.

[0050] For ease of description, various components can be described as performing one or more tasks. Such a description should be interpreted to include the phrase "configured to". A component described as configured to perform one or more tasks is specifically intended not to invoke the interpretation of paragraph 6 of section 112 of title 35 of the United States Code for that component.

[0051] Figures 1 - 2 — Wireless communication system

[0052] Figure 1 Illustrates an example of a wireless cellular communication system. It should be noted that Figure 1Represents one possibility among many possibilities, and the features of the present disclosure can be implemented by any one of various systems as needed. For example, the embodiments described herein can be implemented in any type of wireless device.

[0053] As shown in the figure, an exemplary wireless communication system includes a cellular base station 102 that communicates with one or more wireless devices 106A, wireless device 106B, etc., and accessory device 107 via a transmission medium. Wireless device 106A, wireless device 106B, and wireless device 107 can be user equipment that may be referred to as "user equipment" (UE) or UE devices in the text.

[0054] Base station 102 can be a transceiver base station (BTS) or a cell site and can include hardware and / or software for implementing wireless communication with UE devices 106A, UE device 106B, and UE device 107. If base station 102 is implemented in the context of LTE, it can be referred to as an "eNodeB" or "eNB". If base station 102 is implemented in the context of 5G NR, it can alternatively be referred to as a "gNodeB" or "gNB". Base station 102 can also be equipped to communicate with network 100 (e.g., the core network of a cellular service provider, a telecommunications network such as the public switched telephone network (PSTN), and / or the Internet, and various possible networks). Thus, base station 102 can facilitate communication between UE device 106 and UE device 107 and / or communication between UE devices 106 / 107 and network 100. Similarly, as used herein, with respect to a UE, when considering the uplink (UL) and downlink (DL) communications of the UE, the base station can sometimes be considered to represent the network. Therefore, a UE that communicates with one or more base stations in the network can also be understood as a UE that communicates with the network.

[0055] In other specific implementations, base station 102 can be configured to provide communication via one or more other wireless technologies, such as an access point that supports one or more WLAN protocols (such as 802.11a, b, g, n, ac, ad, and / or ax, or LTE in the unlicensed band (LAA)).

[0056] The communication area (or coverage area) of base station 102 can be referred to as a "cell". Base station 102 and UE 106 / 107 can be configured to communicate via a transmission medium using any one of various radio access technologies (RATs) or wireless communication technologies (such as GSM, UMTS (WCDMA, TDS-CDMA), LTE, advanced LTE (LTE-A), NR, HSPA, 3GPP2 CDMA2000 (e.g., 1xRTT, 1xEV-DO, HRPD, eHRPD), Wi-Fi, etc.).

[0057] Accordingly, the base station 102 and other similar base stations (not shown) operating according to one or more cellular communication technologies may be provided as a cell network that can provide continuous or near-continuous overlapping services to UE devices 106A-N, UE device 107, and similar devices within a geographical area via one or more cellular communication technologies.

[0058] Note that, at least in some cases, UE devices 106 / 107 may be able to communicate using any one of a plurality of wireless communication technologies. For example, UE devices 106 / 107 may be configured to communicate using one or more of GSM, UMTS, CDMA2000, LTE, LTE-A, NR, WLAN, Bluetooth, one or more Global Navigation Satellite Systems (GNSS, such as GPS or GLONASS), one and / or more mobile television broadcast standards (e.g., ATSC-M / H), etc. Other combinations of wireless communication technologies (including more than two wireless communication technologies) are also possible. Similarly, in some cases, UE device 106 / UE device 107 may be configured to communicate using only a single wireless communication technology.

[0059] UE 106A and UE 106B may include handheld devices such as smart phones or tablets, and / or may include any device among various types of devices having cellular communication capabilities. For example, one or more of UE 106A and UE 106B may be wireless devices intended for static or dynamic deployment, such as home appliances, measurement devices, control devices, etc. UE 106B may be configured to communicate with UE device 107, which may be referred to as an accessory device 107. The accessory device 107 may be any one of various types of wireless devices, and is typically a wearable device having a smaller form factor and having limited battery, output power, and / or communication capabilities relative to UE 106. As a common example, UE 106B may be a smart phone carried by a user, and the accessory device 107 may be a smart watch worn by the same user. UE 106B and the accessory device 107 may communicate using any one of various short-range communication protocols such as Bluetooth or Wi-Fi. In some cases, UE 106B and the accessory device 107 may utilize Proximity Services (ProSe) technology, for example, in a manner supported by a cellular base station, to perform direct peer-to-peer communication. For example, such ProSe communication may be performed as part of a relay link to support a radio resource control connection between the accessory device 107 and the BS 102, such as according to various embodiments described herein.

[0060] UE 106B may also be configured to communicate with UE 106A. For example, UE 106A and UE 106B may be capable of performing direct device-to-device (D2D) communication. The D2D communication may be supported by the cellular base station 102 (e.g., BS 102 may facilitate discovery and various possible forms of assistance), or may be performed in a manner not supported by BS 102. For example, it may be possible for UE 106A and UE 106B to arrange and perform D2D communication (e.g., including discovery communication) even when there is no coverage from BS 102 and other cellular base stations.

[0061] BS 102 may control one or more transmit and receive points (TRPs), and may use the TRPs to communicate with the UE. The TRPs may be collocated with the BS and / or at separate physical locations.

[0062] Figure 2 An exemplary BS 102 communicating with the UE device 106 is shown, which in turn communicates with the accessory device 107. The UE device 106 and the accessory device 107 may be any one of a mobile phone, a tablet computer, or any other type of handheld device, a smart watch or other wearable device, a media player, a computer, a laptop, an unmanned aerial vehicle (UAV), an unmanned flight controller, a vehicle, or almost any type of wireless device. In some embodiments, the accessory device may be a wireless device designed to have low cost and / or low power consumption, and may benefit from a relay link with the UE device 106 (and / or another companion device) to support communication with BS 102. For example, in Figure 2 the illustrative scenario, a device that uses a relay link with another wireless device to communicate with a cellular base station may also be referred to herein as a remote wireless device, a remote device, or a remote UE device, while a wireless device that provides such a relay link may also be referred to herein as a relay wireless device, a relay device, or a relay UE device. According to some embodiments, such BS 102, UE 106, and accessory device 107 may be configured to perform radio resource control procedures on the remote wireless device according to the various techniques described herein.

[0063] Both the UE 106 and the accessory device 107 may include a device or integrated circuit, referred to as a cellular modem, for facilitating cellular communication. The cellular modem may include one or more processors (processing elements) configured to execute program instructions stored in a memory and / or various hardware components described herein. The UE 106 and / or the accessory device 107 may each execute any of the method implementations described herein by executing such stored instructions. Alternatively or in addition, the UE 106 and / or the accessory device 107 may include programmable hardware elements, such as FPGAs (field programmable gate arrays), integrated circuits, and / or any of various other possible hardware components, configured to (e.g., individually or in combination) execute any one or any part of any of the method implementations described herein. The cellular modems described herein may be used in UE devices as defined herein, wireless devices as defined herein, or communication devices as defined herein. The cellular modems described herein may also be used in base stations or other similar network-side devices.

[0064] The UE 106 and / or the accessory device 107 may include one or more antennas for communicating according to one or more RAT standards using one or more wireless communication protocols. In some implementations, one or both of the UE 106 or the accessory device 107 may be configured to communicate using a single shared radio component. The shared radio may be coupled to a single antenna or may be coupled to multiple antennas (e.g., for MIMO) for performing wireless communication. Generally, the radio component may include any combination of a baseband processor, analog radio frequency (RF) signal processing circuitry (e.g., including filters, mixers, oscillators, amplifiers, etc.), or digital processing circuitry (e.g., for digital modulation and other digital processing). Similarly, the radio component may implement one or more receive chains and transmit chains using the aforementioned hardware.

[0065] Alternatively, UE 106 and / or accessory device 107 may include two or more radio components. For example, in some embodiments, UE 106 and / or accessory device 107 may include a separate transmit chain and / or receive chain (e.g., including separate antennas and other radio components) for each wireless communication protocol for which it is configured to communicate. As another possibility, UE 106 and / or accessory device 107 may include one or more radio components shared among multiple wireless communication protocols, and one or more radio components uniquely used by a single wireless communication protocol. For example, UE 106 and / or accessory device 107 may include shared radio components for communicating using either LTE or CDMA2000 1xRTT (or LTE or NR, or LTE or GSM), and separate radio components for communicating using each of Wi-Fi and BLUETOOTH TM separately. Other configurations are possible.

[0066] Figure 3 —Block diagram of a UE device

[0067] Figure 3 A possible block diagram of a UE device such as UE device 106 or UE device 107 is shown. As shown, UE device 106 / 107 may include a system-on-chip (SOC) 300, which may include portions for various purposes. For example, as shown, SOC 300 may include a processor 302 and a display circuit 304, the processor may execute program instructions for UE device 106 / 107, and the display circuit may perform graphics processing and provide a display signal to a display 360. SOC 300 may also include a motion sensing circuit 370, which may detect the motion of UE 106 using, for example, a gyroscope, an accelerometer, and / or any of various other motion sensing components. Processor 302 may also be coupled to a memory management unit (MMU) 340, which may be configured to receive addresses from processor 302 and translate those addresses into locations in memory (e.g., memory 306, read-only memory (ROM) 350, flash memory 310) and / or other circuits or devices, such as display circuit 304, radio components 330, I / F 320, and / or display 360. MMU 340 may be configured to perform memory protection and page table translation or setup. In some embodiments, MMU 340 may be included as part of processor 302.

[0068] As shown in the figure, the SOC 300 can be coupled to various other circuits of the UE 106 / 107. For example, the UE 106 / 107 can include various types of memories (e.g., including NAND flash memory 310), a connector interface 320 (e.g., for coupling to a computer system, a docking station, a charging station, etc.), a display 360, and wireless communication circuitry 330 (e.g., for LTE, LTE-A, NR, CDMA2000, Bluetooth, Wi-Fi, NFC, GPS, etc.).

[0069] The UE device 106 / 107 can include at least one antenna and in some embodiments can include multiple antennas 335a and antenna 335b for performing wireless communication with a base station and / or other devices. For example, the UE device 106 / 107 can use the antenna 335a and the antenna 335b to perform wireless communication. As described above, the UE device 106 / 107 can be configured to perform wireless communication using multiple wireless communication standards or radio access technologies (RATs) in some embodiments.

[0070] The wireless communication circuitry 330 can include Wi-Fi logic 332, a cellular modem 334, and Bluetooth logic 336. The Wi-Fi logic 332 is for enabling the UE device 106 / 107 to perform Wi-Fi communication on an 802.11 network. The Bluetooth logic 336 is for enabling the UE device 106 / 107 to perform Bluetooth communication. The cellular modem 334 can be a lower-power cellular modem capable of performing cellular communication according to one or more cellular communication technologies.

[0071] As described herein, the UE 106 / 107 can include hardware components and software components for implementing the embodiments of the present disclosure. For example, by executing program instructions stored on a storage medium (e.g., a non-transitory computer-readable memory medium), the processor 302 of the UE device 106 / 107 can be configured to implement part or all of the methods described herein. In other embodiments, the processor 302 can be configured as a programmable hardware element, such as an FPGA (field-programmable gate array) or as an ASIC (application-specific integrated circuit). Additionally, the processor 302 can be coupled to, such as Figure 3The other components shown and / or may interoperate with the other components to perform radio resource control procedures for a remote wireless device according to various embodiments disclosed herein. The processor 302 may also implement various other applications and / or end-user applications running on the UE 106. Alternatively or in addition, one or more components of the wireless communication circuitry 330 of the UE device 106 / 107 (e.g., the cellular modem 334) may be configured to implement part or all of the methods described herein, for example, by a processor that executes program instructions stored on a memory medium (e.g., a non-transitory computer-readable memory medium), a processor configured as an FPGA (field programmable gate array) and / or using a dedicated hardware component that may include an ASIC (application specific integrated circuit).

[0072] Figure 4 —Block diagram of a base station

[0073] Figure 4 Exemplary block diagram of a base station 102 according to some embodiments is shown. Note that Figure 4 the base station shown is only one example of a possible base station. As shown, the base station 102 may include a processor 404 that may execute program instructions for the base station 102. The processor 404 may also be coupled to a memory management unit (MMU) 440 or other circuitry or device, and the MMU may be configured to receive addresses from the processor 404 and translate these addresses into locations in a memory (e.g., the memory 460 and read-only memory (ROM) 450).

[0074] The base station 102 may include at least one network port 470. As described above in Figure 1 and Figure 2 the network port 470 may be configured to be coupled to a telephone network and provide access to the telephone network for a plurality of devices, such as the UE devices 106 / 107.

[0075] The network port 470 (or an additional network port) may also be configured or alternatively configured to be coupled to a cellular network, such as the core network of a cellular service provider. The core network may provide mobility-related services and / or other services to a plurality of devices, such as the UE devices 106 / 107. For example, the core network may include, for example, a mobility management entity (MME) for providing mobility management services, a serving gateway (SGW) for providing, for example, an external data connection to the Internet, and / or a packet data network gateway (PGW), and so on. In some cases, the network port 470 may be coupled to the telephone network via the core network, and / or the core network may provide the telephone network (e.g., between other UE devices served by the cellular service provider).

[0076] Base station 102 may include at least one antenna 434 and possibly multiple antennas. One or more antennas 434 may be configured to operate as a wireless transceiver and may be further configured to communicate with UE devices 106 / 107 via radio component 430. Antenna 434 communicates with radio component 430 via communication link 432. Communication link 432 may be a receive link, a transmit link, or both. Radio component 430 may be configured to communicate via various wireless communication standards, which include but are not limited to LTE, LTE-A, NR, GSM, UMTS, CDMA2000, Wi-Fi, etc.

[0077] Base station 102 may be configured to perform wireless communication using multiple wireless communication standards. In some cases, base station 102 may include multiple radios that enable base station 102 to communicate according to multiple wireless communication technologies. For example, as a possibility, base station 102 may include an LTE radio for performing communication according to LTE and a Wi-Fi radio for performing communication according to Wi-Fi. In such cases, base station 102 may be able to operate as both an LTE base station and a Wi-Fi access point. As another possibility, base station 102 may include a multi-mode radio component capable of performing communication according to any one of multiple wireless communication technologies (e.g., LTE and NR, LTE and Wi-Fi, LTE and UMTS, LTE and CDMA2000, UMTS and GSM, etc.).

[0078] As further described subsequently herein, BS 102 may include hardware and software components for implementing or supporting the specific implementations of the features described herein. According to some embodiments, processor 404 of base station 102 may be configured to implement part or all of the methods described herein, for example, by executing program instructions stored on a memory medium (e.g., a non-transitory computer-readable memory medium). Alternatively, processor 404 may be configured as a programmable hardware element such as an FPGA (Field Programmable Gate Array), or as an ASIC (Application Specific Integrated Circuit), or a combination thereof. Alternatively (or in addition), in combination with one or more of the other components 430, 432, 434, 440, 450, 460, 470, processor 404 of BS 102 may be configured to implement or support the implementation of radio resource control procedures for remote wireless devices and / or any one of the various other features of the features described herein according to the various embodiments described herein.

[0079] Figure 5 - Communication flowchart

[0080] High-Speed Trains (HSTs) are a deployment scenario of great interest to some operators, especially those from countries / regions where HST systems are deployed (e.g., China). Thus, HST enhancements can be part of the Release 17 further enhanced (Fe) multiple-input multiple-output (MIMO) (FeMIMO). For example, a UE may travel between two transmission and reception points (TRPs) in an HST scenario or other scenarios involving fast movement. The UE may observe a very high positive Doppler shift from one TRP and a very high negative Doppler shift from the other TRP. Thus, the composite channel can change rapidly. For example, Doppler shifts approaching 4 kHz or even larger may be observed. Such shifts can potentially reduce the channel capacity and / or make it very challenging for the UE to perform accurate channel estimation.

[0081] There can be two broad approaches to mitigate this channel variation. In one approach, the UE may estimate two separate Doppler shifts, e.g., one Doppler shift from one TRP, but more than two TRPs can also be envisioned. The different Doppler shifts can be used to assist UE channel estimation, e.g., to perform different channel estimations for different TRPs. In another approach, the network may compensate for the Doppler shift. Thus, the network can determine the Doppler shift for each TRP for compensation.

[0082] Figure 5 is a communication flow diagram showing an exemplary method for performing communication in the case of a fast-moving UE. Figure 5 The method can mitigate some communication challenges associated with fast movement. In various embodiments, some of the elements of the shown method may be executed simultaneously in an order different from the shown order, may be replaced by other method elements, or may be omitted. Additional method elements may also be executed as needed.

[0083] Figure 5 Aspects of the method can be implemented by a UE such as UE 106 or 107, a cellular network, one or more transmission and reception points (TRPs), and / or one or more BSs 102, e.g., as shown and described in the figures as needed, or more generally in conjunction with any of the computer systems, circuits, elements, components, or devices shown in the figures, etc. For example, one or more processors (or processing elements) (in various possibilities, e.g., processor 302, 404, a baseband processor, a processor associated with a communication circuit such as 330, 430, or 432, a processor associated with various core network elements, etc.) may cause the UE, network element, and / or BS to perform some or all of the shown method elements. Note that although the description has been presented in a manner that involves the use of communication technologies and / or features associated with LTE, NR, and / or 3GPP specification documents Figure 5At least some elements of the method, but this description is not intended to limit the present disclosure and may be used in any suitable wireless communication system as needed Figure 5 Aspects of the method. As shown, the method may operate as follows.

[0084] According to some embodiments, the UE may establish communication with the network (502) via two TRPs (TRP 501a and TRP 501b). It should be understood that, according to various embodiments, the TRPs may be controlled by a single BS or by different BSs. The UE may be moving. For example, the UE may be moving towards one of the TRPs 501 and away from the other TRP 501. For example, the UE may be traveling on a high-speed train (or in a car, drone, UAV, or other vehicle) along a route (e.g., a train track, a highway, a road, etc.), and the TRPs 501a and 501b may be along or near the route. Thus, the UE may be getting closer to one TRP 501 and farther away from the other TRP 501. Accordingly, the signals exchanged between the UE and the TRP may be affected by the movement. For example, the signals may exhibit Doppler drift or frequency offset due to the movement of the UE.

[0085] According to some embodiments, the network (e.g., the control BS 102 and / or any one or both of the TRPs 501a and / or 501b) and / or the UE may determine that the UE is moving rapidly (504). For example, the network and / or the TRP 501 may determine that the UE is moving rapidly based on any one or all of the following: radio measurements (e.g., of reference signals or other communications transmitted by the UE), reports from the UE (e.g., radio measurements made by the UE and / or based on the UE's motion sensing features such as an accelerometer, a motion sensor, a gyroscope, a global navigation satellite system such as GPS, etc.), knowledge of the UE's recent movement, and / or knowledge of traffic information (e.g., train schedules, highway routes, knowledge of the movement of other UEs (e.g., multiple UEs in the same train / vehicle), etc.). Thus, in some embodiments, the network may be configured to infer UE movement from various different measurements or inputs. The UE may similarly determine its movement based on similar information, for example.

[0086] In some embodiments, the UE may explicitly indicate information about its movement to the network. For example, the UE may indicate to the network that it is on a high-speed train or is otherwise moving rapidly. Based on receiving such an indication, the network may determine that the UE is moving rapidly.

[0087] According to some embodiments, the network and / or the UE may adapt the communication technology (506) based on the movement of the UE. Among various possibilities, such adaptation may include techniques for coordinating communication between two TRPs (e.g., the TRP that the UE is moving towards and the TRP that the UE is moving away from). Such adaptation may include enhancements in any of the following areas:

[0088] Enhancements for downlink data transmission and reception, for example, via reference signals (RSs) for demodulation. For example, the demodulation reference signals (DMRSs) associated with the physical downlink shared channel (PDSCH) may be scheduled, transmitted, and / or processed differently. For example, two TRPs may transmit DMRSs or other RSs to the UE, for example, for use by the UE communicating with these TRPs simultaneously. The RSs transmitted by different TRPs may be coordinated and orthogonalized in any of various ways (e.g., time division, frequency division, code division, and / or port division). For example, two TRPs may transmit UE-specific RSs to the UE during a first time slot (or frame or other time period) (e.g., during the same or different symbols of the first time slot).

[0089] Enhancements for the transmission of control information to the UE (such as downlink control information (DCI) transmission). For example, the RSs (e.g., DMRSs and / or other RSs) associated with the physical downlink control channel (PDCCH) may be scheduled, transmitted, and / or processed differently, for example, for reliability enhancement. For example, two TRPs may transmit RSs to the UE, for example, for use by the UE communicating with these TRPs simultaneously. Multiple transmission configuration indicator (TCI) states may be provided to the UE and used for communication between the UE and the network, and / or new quasi-co-location (QCL) types may be defined and provided to the UE and used for communication between the UE and the network.

[0090] Enhancements in the spatial relationship of uplink RSs. For example, the configuration of uplink RSs (such as sounding RSs (SRSs)) or downlink path loss RSs for UL power control may be adapted.

[0091] New operation modes (e.g., HST mode). For example, a high-speed traveling mode may be created as a special case (e.g., or a variation) of the single downlink control information (DCI) multi-TRP mode. This new mode may be activated by an explicit indication (e.g., in DCI, RRC, MAC CE, or other control signaling) or by an implicit indication (e.g., based on other conditions).

[0092] According to some embodiments, the UE and the network (e.g., TRP 501a and / or TRP 501b) may communicate (508) using an adapted communication technology. For example, when the UE is traveling rapidly between TRP 501a and TRP 501b, the UE and the network may use the adapted communication technology to exchange data and / or control information. The data and / or control information may be exchanged in the UL and / or DL directions.

[0093] The UE and the network may continue to adapt the communication technology and communicate while the UE is traveling. For example, when the UE passes by a TRP, the relationship with the TRP (e.g., Doppler drift, frequency offset, spatial relationship, QCL, and / or other parameters) may change. For example, when the UE passes by a TRP, the frequency offset relative to the TRP may change sign.

[0094] Additional examples and information regarding various types of adaptations for high-speed movement of the UE (e.g., as introduced above with respect to 506) are described below. It should be understood that according to some embodiments, these examples may be used together (e.g., in any combination of various combinations) and / or individually.

[0095] Downlink Data Enhancement

[0096] When the UE is traveling at a very high speed towards or further away from a TRP, the UE may experience a large frequency offset in terms of Doppler drift, which may be linearly proportional to the UE speed and the carrier frequency. Therefore, at high frequencies and when the UE is traveling very fast (e.g., close to or above 350 km / hr, as in a high-speed train (HST)), the frequency offset (Doppler drift) caused by the UE movement may be close to or exceed 2 kHz, which is equivalent to multiple channel phase and amplitude change cycles per millisecond, and this may be different from typical multi-TRP operations. Due to the high-speed movement in the HST scenario, it may be challenging for the UE to process the rapidly changing variations.

[0097] Figure 6Shows downlink data enhancement according to some embodiments (e.g., via PDSCH DMRS enhancement). As shown, UE 106 can travel between two TRPs (TRP 1 and TRP 2) (e.g., on a train). It should be understood that according to some embodiments, the TRPs can be controlled by a single BS 102 or by different BSs. The RSs transmitted by different TRPs can be orthogonalized in any of various ways (e.g., time division, frequency division, code division, and / or port division). Thus, the RSs transmitted by the TRPs can be used for communication that is temporally overlapping (e.g., simultaneously) with the two TRPs. In other words, the UE can maintain communication with two TRPs simultaneously. For example, two TRPs can transmit RSs to the UE during the same time slot. Different TRPs can use the same or different symbols of the same time slot.

[0098] According to some embodiments, the TRP can transmit DMRS or other RSs according to a non-single frequency network (SFN) mode. For example, DMRSs from different TRPs can be transmitted to a fast-moving UE that is communicating with the two TRPs in the following cases: (1) at different times (e.g., time division multiplexing (TDM)), and / or (2) at different frequency positions (e.g., frequency division multiplexing (FDM)), and / or (3) having different DMRS ports, and / or (4) having different orthogonal codes (e.g., code division multiplexing (CDM)). For example, in response to determining that the UE is moving fast (e.g., in 504), the network can determine to transmit DMRS (and / or other RSs) from multiple TRPs to the UE, for example, simultaneously or at overlapping or alternating times for the UE to use. The UE can use the DMRS (and / or other RSs) when demodulating the downlink data and / or control information transmitted by the corresponding TRP.

[0099] In some embodiments, the RSs (e.g., DMRS) transmitted to the UE from different TRPs can be UE-specific. In other words, specific RSs can be transmitted to the UE based on any of various factors such as the movement of the UE, the scheduled communication between the UE and the TRP, radio measurements of the channel between the UE and the TRP, etc. According to some embodiments, the RSs transmitted to the UE from different TRPs can be the same or can be different.

[0100] In some embodiments, different from the current DMRS design, different TRPs can transmit different RS (e.g., DMRS) patterns to the UE. Thus, the UE can separate the RSs from different TRPs. This distinction between the RSs can reduce the channel variation caused by the high UE movement speed and improve the UE channel estimation quality. Thus, according to some embodiments, the RSs can be UE-specific and TRP-specific.

[0101] As Figure 7As shown, DMRSs from different TRPs (e.g., or UE-specific RSs) can be transmitted at different times (e.g., symbols 0 to 13 of a time slot are shown horizontally in time; the frequency domain is shown vertically). For example, the DMRS position (e.g., in time / frequency) of the first TRP (e.g., TRP 501a) can be known from existing standards and / or configuration information. The DMRS position (e.g., in time / frequency) of the second TRP (e.g., TRP 501b) can be indicated via additional control information (e.g., radio resource control (RRC), medium access control (MAC) control element (CE), and / or downlink control information (DCI), etc.). Among various possibilities, the control information can be sent via multiple TRPs or via one of the TRPs. For example, both the first TRP and the second TRP can transmit the control information, or only one of the TRPs (e.g., the first TRP or the second TRP) can transmit the control information. Similarly, the DMRS position of the second TRP can be implicitly determined by the UE.

[0102] For example, the new (e.g., additional) symbol position of the DMRS for the second (e.g., additional) TRP can be explicitly defined in the technical specification or defined relative to the symbol position of the DMRS for the first TRP. For example, the network can send control information indicating the position of the DMRS from the second UE to the UE. The control information can explicitly identify the specific position of the DMRS (e.g., in terms of symbols and resource elements (REs)). For example, in Figure 7 , the positions of the DMRSs of TRP 2 can be in symbols 1 and 8. Alternatively, the control information can indicate the offset of the DMRS position of the second TRP relative to the first TRP (e.g., in the Figure 7 example, the position of the DMRS of TRP 2 can be offset by 1 symbol relative to the DMRS of TRP1).

[0103] In some embodiments, when multiple DMRS positions are configured, the existing DMRS symbol positions can be divided between the first TRP and the second TRP (e.g., the symbols designated for DMRS transmission according to existing specifications and / or control information). In other words, if a first number of REs in a time slot can be designated for RS (e.g., by previous control information and / or standards), then the first number of REs can be subdivided such that a subset of the REs is for the RS of TRP 1 and a second subset of the REs is for the RS of TRP 2. When the second RS is configured, control information can be used to indicate the subdivision of the RS positions.

[0104] It should be understood that although the temporal positions (e.g., symbols) of the RSs associated with the TRPs are different, the UE is communicating with the TRPs simultaneously. In other words, the temporal positions overlap and are time division multiplexed (TDMd). For example, a TRP may transmit RSs in different symbols of the same time slot. For example, a first TRP may use one or more first symbols, and a second TRP may use one or more second symbols.

[0105] Figure 8 DMRS transmissions from different TRPs at different frequencies are shown according to some embodiments. Any combination of the above techniques may be used to indicate Figure 8 the DMRS transmissions. For example, the RS position may be indicated explicitly or using an offset; existing RS positions may be subdivided.

[0106] Another method for orthogonalizing the RSs of different TRPs may be via code division multiplexing (CDM). For example, DMRSs from different TRPs may be transmitted in different CDM groups. According to some embodiments, each CDM group may support up to four ports via orthogonal codes. Different CDM groups may be orthogonalized via frequency division multiplexing (FDM). Depending on the number of CDM groups configured for the UE, various methods may be used to orthogonalize the RSs of the TRPs.

[0107] When a single CDM group is configured, there may be one or more (e.g., predefined) ports indicated for the DMRS (e.g., or other RS) in the CDM group. Thus, the one or more ports indicated for the RS may be used for the transmission of the RS and / or data for one TRP. One or more other ports (e.g., the remaining ports) of the CDM group may be used for the transmission of the RS and / or data for another TRP. In some embodiments, which ports are used for which TRPs may be signaled explicitly in the control information or indicated implicitly (e.g., based on scheduling a single TRP on a particular port). For example, if 1 CDM group is configured (e.g., via DCI) and the DCI (or other control information) indicates the port (or ports) for the DMRS, then that port (or ports) may be used for the first TRP; any other port may be used for the DMRS of other TRPs. In some embodiments, the data from each TRP may use the same ports as the RS from the corresponding TRP.

[0108] When two CDM groups are configured, the DMRS ports in the first CDM group may correspond to one TRP, and the DMRS ports in the second CDM group may correspond to another TRP. Thus, as Figure 9As shown, the REs can be partitioned between the two CDM groups (e.g., alternately in this example, but other partitions can be used as needed). Each CDM group can be used for DMRS from different TRPs. In the example shown, the REs in the first CDM group can be used for DMRS from the first TRP, and the REs in the second CDM group can be used for DMRS from the second TRP. The transmission of CDM group 1 can be performed by one TRP, and the transmission of CDM group 2 can be performed by another TRP. The UE can (e.g., jointly) use the DMRS of each TRP (e.g., each CDM group) to demodulate the corresponding data. For example, in the case where two TRPs transmit duplicate data (e.g., TRP2 transmits a copy of the data transmitted by TRP 1), the UE can use a combination of the DMRS from each TRP to estimate the channel and demodulate the data. Alternatively, in the case where two TRPs transmit different data, the UE can use the DMR from one TRP to estimate the channel from that TRP and demodulate the data. The data can be transmitted at a different frequency (e.g., simultaneously with the RS), at a different time from the RS (e.g., different symbols, but possibly the same frequency), and / or using a different antenna port from the RS.

[0109] When three CDM groups are configured, the DMRS ports in the first subset (e.g., 1 or 2) of the CDM groups can correspond to one TRP, and the DMRS ports in the remaining groups of the CDM groups can correspond to another TRP. Figure 10 An example with three CDM groups is shown according to some embodiments. CDM group 0 can correspond to the first TRP, and CDM groups 1 and 2 can correspond to the second TRP. In the example shown, the REs in CDM group 0 can be used for DMRS corresponding to the first TRP, and the REs in CDM groups 1 and 2 can be used for DMRS corresponding to the second TRP. The UE can (e.g., jointly in the case where different TRPs transmit duplicate data) use the DMRS from both the first and second TRPs transmitted in CDM groups 0, 1, and 2 to decode the data of the PDSCH channel. Alternatively, in the case where the TRPs transmit different data, the UE can use the DMRS of CDM group 1 to decode the data of CDM group 2, e.g., because CDM groups 1 and 2 are transmitted by the same TRP and thus share channel characteristics. Note that partitioning can also be performed such that CDM groups 0 and 1 correspond to the first TRP, and CDM group 2 corresponds to the second TRP.

[0110] In another method for orthogonalizing the RS, different ports can be used to transmit the RS from different TRPs. For example, the UE can receive the RS from different TRPs using different antenna ports.

[0111] In some embodiments, a second antenna port field may be introduced in the DCI. The second antenna port field may be a copy (e.g., duplication) of an existing port field. Thus, the network (e.g., a base station) may indicate, for example, via the DCI, the antenna port configuration for the RS from each TRP individually. For example, in a DCI message to the UE, the network may indicate a first port for the DMRS of TRP 1 and a second port for the DMRS of TRP 2.

[0112] In some embodiments, a new table for antenna port field interpretation may be introduced (e.g., in 38.212). This table may specify at least some values of the antenna port field for two different ports (e.g., for different TRPs). Thus, for such antenna port field indication, two sets of DMRS ports may be defined: a first set of DMRS ports for a first TRP and a second set of DMRS ports for a second TRP.

[0113] In some embodiments, the data transmitted from the TRPs (e.g., associated with the RS) may be the same. For example, a first TRP may transmit first data to the UE during a time slot. During the same time slot (e.g., in the same and / or different symbols, e.g., using any of the orthogonalization techniques discussed above), a second TRP may transmit second data to the UE. The second data may be a copy of the first data. The first data may be demodulated using the RS from the first TRP, and the second data may be demodulated using the RS from the second TRP. The UE may combine these channels before decoding the data. In other words, the UE may rely on both the first data and the second data (e.g., a copy of the first data) to determine the content of the first data / second data.

[0114] Downlink Control Channel Enhancement

[0115] Figures 11 to 15 Aspects of downlink control channel (e.g., PDCCH) reliability enhancement according to some embodiments are shown. According to some embodiments, multiple TRPs may use the same control resource set (CORESET) to transmit control information to the UE. Similar to the discussion of downlink data enhancement above, the RSs transmitted by different TRPs may be orthogonalized in various ways (e.g., frequency division, code division, and / or port division). Thus, the RSs transmitted by the TRPs may be used for communication that is temporally overlapping (e.g., simultaneous) with two TRPs. In other words, the UE may maintain communication with two TRPs simultaneously. For example, two TRPs may transmit UE-specific RSs to the same UE during each symbol of the CORESET. Additionally, as described above, the RSs may be TRP-specific, and the UE may distinguish between the RSs of different TRPs.

[0116] In addition, according to some embodiments, the various techniques discussed above (e.g., with respect to downlink data) may be adapted for use with control channels. It should be understood that current control channel designs include RS in each symbol (e.g., time interval), and thus time division may not be applicable. However, according to some embodiments, time division as discussed above with respect to data enhancement may also be applied to control channels that do not include RS in each time interval.

[0117] In some embodiments, the PDCCH may have separate RS (e.g., DMRS) transmissions from different TRPs. For example, in addition to the first TRP, the RS associated with the PDCCH may be transmitted from a second TRP, for example.

[0118] As a method for orthogonalizing the RS of different TRPs, frequency division may be used. Figure 11 A combined resource grid according to some embodiments is shown, e.g., showing DMRS transmissions from each TRP on the control channel. According to some embodiments, Figure 12 shows the DMRS transmission from TRP 1, and Figure 13 shows the DMRS transmission from TRP 2. In other words, Figure 12 and Figure 13 show the separate RS transmissions of TRP 1 and 2 according to some embodiments, respectively.

[0119] As shown, the DMRS may be transmitted by each TRP in each symbol of the CORESET. The DMRS may be transmitted by each TRP at various frequencies (e.g., in periodically spaced REs). In the example shown, the DMRS may be transmitted by each TRP in every fourth RE in each CORESET symbol. Note that other intervals may be used as needed. For example, the RE offset of the DMRS of TRP 2 is three, and the RE offset of the DMRS of TRP 1 is one. In other words, the DMRS of each TRP may occur in every 4 REs, where TRP 1 is in the second RE (e.g., offset of 1) and TRP 2 is in the fourth RE (e.g., offset of 3).

[0120] As another method for orthogonalizing the RS of different TRPs, code division may be used. In other words, different TRPs may transmit the RS at the same time and at the same frequency, but orthogonal codes may be used for transmission. For example, in a symbol, for a corresponding resource block (RB), the first RE and the second RE may be used for the DMRS. Other patterns may be used as needed.

[0121] Figure 14 and Figure 15 illustrates code division multiplexing (CDM) of the RS for the downlink control channel according to some embodiments. AsFigure 14 As shown, TRP 1 can use pattern (1 1) to transmit RS, and as Figure 15 shown, TRP 2 can use pattern (1 -1). Based on the orthogonality of these patterns, the UE may be able to receive both the RS from TRP 1 and the RS from TRP 2 and use these RSs to demodulate the control information from TRP 1 and TRP 2. The TRP may transmit control information in the REs not used for RS transmission.

[0122] Another method for enhancing the reliability of the downlink control channel may include configuring different transmission configuration indication (TCI) states for different TRPs. In some embodiments, the MAC CE may be used to configure two TTIs for the CORESET PDCCH. For example, the first TRP may transmit a MAC CE to the UE, and the MAC CE indicates the first TCI of the first TRP and the second TCI of the second TRP.

[0123] The TCI state may indicate the quasi - co - location (QCL) relationship between one or more of various (e.g., periodic) RSs and the control and / or data channels (e.g., PDCCH and / or PDSCH, etc.) that the TRP may use to transmit to the UE. Thus, the UE may use the RS (e.g., according to the QCL of the TCI with the control and / or data channel) to decode the DL transmission from TRP 501. The TRP501 may use higher - layer signaling (e.g., radio resource control (RRC)) to configure any number of TCI states and (e.g., later) use lower - layer signaling (e.g., downlink control information (DCI)) to select the TCI state to be used.

[0124] In some embodiments, multiple TCI code points may be defined and configured by the RRC. The TCI code point may contain two TCI states, for example, one TCI state for each of two TRPs. Thus, in response to the indication of a TCI code point having two TCI states (e.g., in DCI or MAC CE), the UE may use the first TCI state for the first TRP and the second TCI state for the second TRP. It should be understood that a TCI code point having one TCI state may be used for single - TRP operation and / or single - DCI operation. Additionally, according to some embodiments, TCI code points having more than two TCI states may be used.

[0125] In some embodiments, the MAC CE may indicate two TCI states for the same CORESET. Figure 16A MAC CE indicating a second TCI state is shown (e.g., TCI state ID 2 is added). Thus, in response to receiving a MAC CE with two TCI state IDs, the UE can use the first TCI state for the first TRP and the second TCI state for the second TRP. A MAC CE with a single TCI state ID can be used for single TRP operation and / or single DCI operation.

[0126] Another method for enhancing the reliability of the downlink control channel may include using a new quasi - co - located (QCL) type to indicate that two reference signals (RSs) are QCL with respect to Doppler shift or frequency offset. In a standard document (e.g., 3GPP Release 15), the following four QCL types may be previously defined (see, for example, 5.1.5 in 38.214):

[0127] 'QCL - type A': {Doppler shift, Doppler spread, average delay, delay spread},

[0128] 'QCL - type B': {Doppler shift, Doppler spread},

[0129] 'QCL - type C': {Doppler shift, average delay}, and

[0130] 'QCL - type D': {spatial Rx parameters}.

[0131] Therefore, in some embodiments, a fifth QCL type (e.g., TypeE) may be defined. The fifth type may be described, for example, as:

[0132] 'QCL TypeE': {Doppler shift}

[0133] In other words, the new type can be, for example, an independent QCL based only on Doppler shift. This can be contrasted with the current QCL types, which may bundle Doppler shift with other properties (e.g., Doppler spread in the case of QCL - type B).

[0134] In some embodiments, the control information data transmitted from a TRP (e.g., associated with an RS) may be the same. For example, a first TRP may transmit first control information to a UE during a time slot / CORESET. During the same time slot / CORESET (e.g., using any of the orthogonalization techniques discussed above), a second TRP may transmit second control information to the UE. The second control information may be a copy of the first control information. The first control information may be demodulated using the RS from the first TRP, and the second control information may be demodulated using the RS from the second TRP. The UE may combine these channels before decoding the control information. In other words, the UE may rely on both the first control information and the second control information (e.g., a copy of the first control information) to determine the content of the first control information / second control information.

[0135] Uplink RS Enhancement

[0136] The sounding reference signal (SRS) and / or other uplink RSs may be enhanced to support uplink transmissions to the network. For example, the uplink RS may be used by the network to determine the UE speed and / or for channel estimation and / or to correct for UE movement.

[0137] In some embodiments, a MAC CE may be used to update the configuration for periodic SRS (P-SRS). For example, the MAC CE may be used to indicate which path loss RS may be used by the UE to estimate the path loss between the UE and the TRP for determining the transmission power of the P-SRS based on open-loop power control. The same MAC CE or a different MAC CE may be used to indicate the spatial relationship (e.g., the uplink beam of the UE) to be used for transmitting the uplink RS. The MAC CE may indicate multiple spatial relationships (e.g., similar to the discussion of directly indicating multiple TCI states or indicating a TCI code point with multiple TCIs for one MAC CE). For example, the MAC CE may directly indicate multiple spatial relationships, or may indicate a spatial relationship code point that defines multiple spatial relationships. Thus, the UE may use multiple spatial relationships to transmit the RS. The multiple spatial relationships may correspond to multiple TRPs (e.g., a first spatial relationship with a first TRP, etc.). The network may use the RS received at the corresponding TRP to estimate the channel between the UE and the corresponding TRP and / or to demodulate the uplink transmission from the UE to the corresponding TRP. Updating the configuration of the uplink RS (e.g., including the spatial relationship) using a MAC CE may be faster than updating the configuration using RRC. According to some embodiments, DCI may be used to update the configuration of the uplink RS.

[0138] In some embodiments, the spatial relation definition may be extended to include a frequency offset. Thus, according to one or more configured spatial relations, the UE may transmit SRS or other uplink RS based on the frequency offset estimated from the spatial relation RS. In some embodiments, the spatial relation RS may be configured as a downlink RS (e.g., CSI-RS or SSB), an uplink RS (e.g., SRS), or both a downlink RS and an uplink RS. In other words, the UE may offset the frequency of the transmitted uplink RS by the frequency offset of the spatial relation. Thus, the UE may "pre-correct" the uplink RS for the Doppler drift associated with the UE's movement. Different frequency offsets may be used for different spatial relations. For example, the UE may use a first spatial relation with a first offset for transmission to a first TRP and a second spatial relation with a second offset for transmission to a second TRP. The frequency offset may be determined in various ways. For example, the network may determine one or more frequency offsets (e.g., based on measurements of previous uplink RS from the UE, data reported from the UE, or other knowledge of the UE's movement) and may indicate the frequency offsets for the UE to use for one or more spatial relations. As another example, the UE may determine the frequency offset of the spatial relation (e.g., based on measurements of the downlink RS or other knowledge of the UE's movement). In some embodiments, the frequency offset of one spatial relation may be determined based on the frequency offset of another spatial relation. For example, if the frequency offset of a TRP in front of the UE (e.g., in the direction of the UE's travel) is known, the frequency offset of another TRP behind the UE may be determined by inverting the sign of the frequency offset (e.g., multiplying by -1).

[0139] In some embodiments, the UE may transmit SRS or other uplink RS based on an absolute channel number (e.g., frequency without offset, e.g., as determined by a lower layer (e.g., layer 1)), regardless of the estimated frequency offset. In other words, the uplink RS may be transmitted without any frequency correction (by the UE) for the UE's movement. On the receiver side, the TRP may estimate the UE frequency offset due to the UE's movement based on the SRS. Based on the UE frequency offset estimate, the TRP may correct for the UE's movement. For example, according to some embodiments, the TRP may apply an offset (e.g., opposite) frequency offset during transmission to the UE, e.g., such that the received signal at the UE side is not affected by the UE's movement.

[0140] In some embodiments, the Tracking Reference Signal (TRS) can be configured with a spatial relationship to the Semi-Persistent (SP) SRS, the Aperiodic (AP) SRS, and / or the P-SRS. For example, the UE can estimate a frequency offset based on the configured TRS, and the frequency offset can be used to determine the UL transmission frequency of the P / SP / AP-SRS for which the TRS is configured with the spatial relationship.

[0141] New communication mode in the case of a fast-moving UE

[0142] The new operation mode can be configured to be used by the network and the UE when the UE is moving fast. For example, among various possibilities, this mode can be referred to as the High-Speed Train (HST) mode. This mode can be used for single-DCI multi-TRP operation. For example, the Release 16 single-DCI multi-TRP operation can be enhanced to support fast movement, such as for a UE on an HST. In other words, a special mode of the single-DCI multi-TRP operation can be configured.

[0143] In some embodiments, in this new mode, the RRC-configured TCI code point can include two TCI states. For example, as discussed above, one TCI state can be used to communicate with one TRP, while the other TCI state can be used to communicate with another TRP. For example, the UE can transmit uplink RS according to the TCI state, and / or the network can transmit downlink RS to the UE according to the TCI state.

[0144] In some embodiments, in the new mode, QCL and / or spatial relationships can be configured for multiple TRPs.

[0145] In some embodiments, in the new mode, various adaptations discussed above can be applied by the UE and / or the network / TRP.

[0146] In some embodiments, in the new mode, one of the TRPs can provide DCI for uplink and downlink communication with two TRPs.

[0147] When one or more of the following conditions are true, the new mode can be entered (e.g., by the UE and / or the network / TRP):

[0148] The first condition can include that repetitionScheme-r16 is not configured by RRC. In other words, according to some embodiments, the first condition can include that none of the following single-DCI multi-TRP modes are configured: (1) FDMSchemeA, (2) FDMSchemeB, and / or (3) TDMSchemeA.

[0149] The second condition may include at least one of the following conditions: repetitionNumber-r16 is not configured in any entry in PDSCH-TimeDomainResourceAllocation and / or repetitionNumber-r16 is not indicated in the DCI field time domain resource assignment. In other words, the single DCI multi-TRP scheme 4 or the inter-slot TDM scheme is not configurable.

[0150] If both of the above two conditions are true, and 1 or 3 CDM groups are indicated in the DCI antenna port field, the network and / or the UE may regard these conditions as an implicit indication to operate according to the new operation mode. For example, the third condition may include configuring one or three CDM groups.

[0151] Alternatively, the network may explicitly configure (e.g., by RRC and / or MAC CE) the new operation mode.

[0152] Based on the implicit or explicit indication, the UE and the network may operate according to the new mode, for example until the condition changes or an explicit indication to change the mode is sent.

[0153] In some embodiments, an additional condition for entering the new mode may be that the UE is moving fast (e.g., above a threshold speed). Thus, if the UE is not moving fast enough, the UE may not enter the new mode. Motion / speed may be determined based on various means, including but not limited to radio measurements, GNSS, motion sensors, etc.

[0154] In some embodiments, frequency offset may be used to correct the Doppler drift of the downlink RS transmitted by one or more TRPs in a manner similar to that described above for the uplink RS.

[0155] In some embodiments, the UE may determine frequency offset information based on the downlink RS from one or more TRPs. The UE may apply the frequency offset information to the transmission of the uplink RS to one or more TRPs.

[0156] In some embodiments, the network may determine frequency offset information based on the uplink RS from the UE to one or more TRPs. The network may apply the frequency offset information to the transmission of the downlink RS from one or more TRPs to the UE.

[0157] In a first set of embodiments, a base station may include: a radio component; and a processor operatively connected to the radio component and configured to cause the base station to: transmit a first reference signal (RS) from a first transmission and reception point (TRP) to a user equipment device (UE) during a first symbol; transmit a second RS from a second TRP to the UE during the first symbol; transmit first control information from the first TRP to the UE during the first symbol, wherein the first control information is configured to be demodulated using the first RS; and transmit second control information from the second TRP to the UE during the first symbol, wherein the second control information is configured to be demodulated using the second RS.

[0158] In some embodiments, the first RS and the second RS may be transmitted at a plurality of resource elements during the first symbol, wherein the resource elements on which the second RS is transmitted are offset with respect to the resource elements on which the first RS is transmitted.

[0159] In some embodiments, the first RS and the second RS may be transmitted at a plurality of resource elements during the first symbol, wherein the resource elements on which the second RS is transmitted are the same as the resource elements on which the first RS is transmitted, and wherein the first RS and the second RS are orthogonalized using code division multiplexing.

[0160] In some embodiments, the processor may be further configured to cause the base station to: transmit control information from the first TRP to the UE, the control information including a transmission configuration indication (TCI) code point, wherein the TCI code point indicates a first TCI state and a second TCI state, wherein the first RS is transmitted according to the first TCI state, and the second RS is transmitted according to the second TCI state.

[0161] In some embodiments, the processor may be further configured to cause the base station to: transmit control information from the first TRP to the UE, the control information including a medium access control (MAC) control element (CE), wherein the MAC CE indicates a first transmission configuration indication (TCI) state and a second TCI state of a first control resource set (CORESET), wherein the first RS is transmitted according to the first TCI state, and the second RS is transmitted according to the second TCI state, and wherein the first symbol is associated with the first CORESET.

[0162] In some embodiments, the processor may be further configured to cause the base station to: transmit control information from the first TRP to the UE, the control information including an indication that the first RS and a third RS are quasi co-located with respect to at least one of Doppler drift or frequency offset.

[0163] In some embodiments, the control information may further include an indication that the second RS and the fourth RS are quasi - co - located with respect to at least one of Doppler drift or frequency offset.

[0164] In some embodiments, the processor may be further configured to cause the base station to: transmit control information from the first TRP to the UE, the control information including a Medium Access Control (MAC) Control Element (CE), where the MAC CE indicates to the UE an update to the configuration of the periodic sounding RS; and receive the periodic sounding RS from the UE at the first TRP and the second TRP according to the configuration.

[0165] In a second set of embodiments, an apparatus may include: a processor configured to cause a base station of a cellular network to: establish communication with a UE via a first Transmission and Reception Point (TRP); transmit a Medium Access Control (MAC) Control Element (CE) from the first TRP to the UE, where the MAC CE includes an indication of using multiple spatial relations to transmit an uplink periodic Reference Signal (RS); receive the uplink RS from the UE via the first TRP according to a first spatial relation among the multiple spatial relations; and receive the uplink RS from the UE via a second TRP according to a second spatial relation among the multiple spatial relations.

[0166] In some embodiments, the uplink periodic RS may be a sounding RS.

[0167] In some embodiments, the MAC CE further includes an indication of a path - loss RS for uplink power control of the uplink periodic RS.

[0168] In some embodiments, the first spatial relation may include a first frequency offset.

[0169] In some embodiments, the second spatial relation may include a second frequency offset different from the first frequency offset.

[0170] In some embodiments, the processor may be further configured to cause the base station to determine that the UE is moving rapidly between the first TRP and the second TRP, where the transmission of the MAC CE is in response to the determination.

[0171] In some embodiments, the processor may be further configured to cause the base station to compensate for the Doppler drift of the uplink RS, where the Doppler drift of the uplink RS received via the first TRP is different from the Doppler drift of the uplink RS received via the second TRP.

[0172] In a third set of embodiments, a method may include: at a cellular network, establishing communication with a user equipment device (UE); determining that the UE is moving rapidly between a first transmission and reception point (TRP) and a second TRP; in response to the determination: causing the first TRP to transmit a first demodulation reference signal (DMRS) to the UE on a first time / frequency resource, where the first time / frequency resource is within a first time slot and where the first DMRS is UE-specific; and causing the second TRP to transmit a second DMRS to the UE on a second time / frequency resource, where the second time / frequency resource is within the first time slot and different from the first time / frequency resource, where the second DMRS is UE-specific; causing the first TRP to transmit first data to be demodulated using the first DMRS; and causing the second TRP to transmit second data to be demodulated using the second DMRS.

[0173] In some embodiments, the first time / frequency resource is a time / frequency resource associated with DMRS transmissions to UEs not determined to be moving rapidly.

[0174] In some embodiments, the method may further include: causing at least one of the first TRP or the second TRP to transmit an indication of the second time / frequency resource to the UE.

[0175] In some embodiments, the indication may include an indication of the offset of the second time / frequency resource relative to the first time / frequency resource.

[0176] In some embodiments, the method may further include: splitting the time / frequency resource associated with DMRS transmissions to the UE not determined to be moving rapidly, where the second time / frequency resource and the first time / frequency resource are separate subsets of the time / frequency resource associated with DMRS transmissions to the UE not determined to be moving rapidly.

[0177] In some embodiments, the first time / frequency resource may be associated with a first code division multiplexing (CDM) group and the second time / frequency resource is associated with a second CDM group.

[0178] In a fourth set of embodiments, a user equipment device (UE) may include: radio components; and a processor operatively connected to the radio components and configured to cause the UE to: determine that the UE is moving rapidly between a first transmission and reception point (TRP) and a second TRP; that no repetition scheme is configured; and that one or three code division multiplexing groups are indicated in an antenna port field; in response to the determination, enter a first operating mode, where the first operating mode is associated with high-speed travel.

[0179] In some embodiments, the first operation mode may include a single downlink control information (DCI) multi-TRP mode.

[0180] In some embodiments, according to the first mode, a transmission configuration indication (TCI) code point may be configured, where the TCI code point indicates a first TCI state and a second TCI state.

[0181] In some embodiments, the processor may be further configured to cause the UE: to receive a first reference signal (RS) from the first TRP according to the first TCI state; and to receive a second RS from the second TRP according to the second TCI state.

[0182] In some embodiments, the first RS may be a channel state information RS, where the first RS is received during a first symbol, where the processor may be further configured to cause the UE: to receive control information from the first TRP during the first symbol; and to demodulate the control information using the first RS.

[0183] In some embodiments, the processor may be further configured to cause the UE: to transmit a first reference signal (RS) to the first TRP according to the first TCI state; and to transmit a second RS to the second TRP according to the second TCI state.

[0184] In some embodiments, the processor may be further configured to cause the UE to perform uplink transmissions to the first TRP and to the second TRP according to the first mode.

[0185] In a fifth group of embodiments, an apparatus may include: a processor configured to cause a user equipment device (UE) to: establish communication with a first transmission and reception point (TRP) of a network; receive a media access control (MAC) control element (CE) from the first TRP, where the MAC CE includes an indication to transmit an uplink periodic reference signal (RS) using a plurality of spatial relations; transmit the uplink RS to the first TRP according to a first spatial relation among the plurality of spatial relations; and transmit the uplink RS to the second TRP according to a second spatial relation among the plurality of spatial relations.

[0186] In some embodiments, the processor may be a baseband processor.

[0187] In some embodiments, the uplink periodic RS may be a sounding RS.

[0188] In some embodiments, the MAC CE includes an indication of a path loss RS for uplink power control of the uplink periodic RS.

[0189] In some embodiments, transmitting the uplink RS to the first TRP may include performing uplink power control based on the path loss RS from the first TRP.

[0190] In some embodiments, transmitting the uplink RS to the second TRP may include performing uplink power control based on the path loss RS from the second TRP.

[0191] In some embodiments, the first spatial relationship may include a first frequency offset.

[0192] In some embodiments, the second spatial relationship may include a second frequency offset different from the first frequency offset.

[0193] In some embodiments, transmitting the uplink RS according to the first spatial relationship may correct the uplink RS for the movement of the UE.

[0194] In some embodiments, transmitting the uplink RS may be based on a channel number without a frequency offset.

[0195] In a sixth set of embodiments, a method may include: at a user equipment (UE): establishing communication with a cellular network; receiving a first downlink reference signal (RS) from a first transmission and reception point (TRP) of the cellular network; receiving a second downlink RS from a second TRP of the cellular network, wherein the second downlink RS is orthogonal to the first downlink RS; communicating with the first TRP and the second TRP simultaneously, wherein the communication includes: receiving a first downlink signal from the first TRP; demodulating the first downlink signal using the first downlink RS; receiving a second downlink signal from the second TRP; and demodulating the second downlink signal using the second downlink RS.

[0196] In some embodiments, the first downlink RS and the second downlink RS may be time-division multiplexed, wherein the first downlink signal and the second downlink signal may be data communications.

[0197] In some embodiments, the first downlink RS and the second downlink RS may be received according to different antenna ports.

[0198] In some embodiments, the first downlink RS and the second downlink RS may be code-division multiplexed.

[0199] In some embodiments, the first downlink RS and the second downlink RS may be frequency-division multiplexed.

[0200] In some embodiments, the method may further include: determining frequency offset information based on the first downlink RS; and applying the frequency offset information to a first uplink RS transmitted to the first TRP.

[0201] In various embodiments, the various combinations of the above adjustments may be performed together. For example, the network may send control information to the UE to cause the UE to process the downlink RS according to the above embodiments and transmit the uplink RS according to the above embodiments.

[0202] Another exemplary embodiment may include a method, including: by a wireless device: performing any or all parts of the foregoing examples.

[0203] Another exemplary embodiment may include a wireless device, the wireless device including: an antenna; radio components coupled to the antenna; and a processing element operatively coupled to the radio components, wherein the device is configured to implement any or all parts of the foregoing examples.

[0204] Another exemplary embodiment may include a device, the device including: a processing element configured to cause a wireless device to implement any or all parts of the foregoing examples.

[0205] Another exemplary set of embodiments may include a non-transitory computer-accessible memory medium including program instructions that, when executed at a device, cause the device to implement any or all parts of any one of the foregoing examples.

[0206] Another exemplary set of embodiments may include a computer program including instructions for performing any or all parts of any one of the foregoing examples.

[0207] Another exemplary set of embodiments may include a device, the device including means for performing any or all elements of any one of the foregoing examples.

[0208] By interpreting each message / signal X received by a user equipment (UE) in the DL as a message / signal X transmitted by a base station, and interpreting each message / signal Y transmitted by the UE in the UL as a message / signal Y received by the base station, any method among the methods for operating a UE described herein can form the basis for a corresponding method for operating a base station.

[0209] In addition to the above exemplary embodiments, further embodiments of the present disclosure may be implemented in any of a variety of forms. For example, some embodiments may be implemented as a computer-implemented method, a computer-readable memory medium, or a computer system. Other embodiments may be implemented using one or more custom-designed hardware devices such as an ASIC. Still other embodiments may be implemented using one or more programmable hardware elements such as an FPGA.

[0210] In some embodiments, a non-transitory computer-readable memory medium may be configured such that it stores program instructions and / or data, where if executed by a computer system, the program instructions cause the computer system to perform a method, such as any of the method embodiments described herein, or any combination of the method embodiments described herein, or any subset of any of the method embodiments described herein or any combination of such subsets.

[0211] In some embodiments, a device (e.g., UE 106 or 107) may be configured to include a processor (or a group of processors) and a memory medium, where the memory medium stores program instructions, where the processor is configured to read and execute the program instructions from the memory medium, where the program instructions may be executed to implement any of the various method embodiments described herein (or any combination of the method embodiments described herein, or any subset of any of the method embodiments described herein or any combination of such subsets). The device may be implemented in any of a variety of forms.

[0212] It is well known that the use of personally identifiable information should follow privacy policies and practices that are generally recognized as meeting or exceeding industry or government requirements for maintaining user privacy. Specifically, personally identifiable information data should be managed and processed to minimize the risk of inadvertent or unauthorized access or use, and the nature of authorized use should be clearly explained to users.

[0213] While the above embodiments have been described in considerable detail, many variations and modifications will become apparent to those skilled in the art once the above disclosure is fully understood. The present disclosure is intended that the following claims be construed to cover all such variations and modifications.

Claims

1. A method for wireless communication, the method comprising: Determining that three conditions for entering a high-speed moving operation mode are satisfied, wherein the three conditions are: A user equipment (UE) is moving rapidly between a first transmission and reception point (TRP) and a second TRP; Radio resource control (RRC) has not configured a repetition scheme for the UE; And One or three code division multiplexing groups are indicated for the UE in the antenna port field; and In response to the determination, entering the high-speed moving operation mode.

2. The method according to claim 1, wherein the high-speed moving operation mode includes a single downlink control information (DCI) multi-TRP mode.

3. The method according to claim 1, wherein according to the high-speed moving operation mode, a transmission configuration indication (TCI) code point is configured, wherein the TCI code point indicates a first TCI state and a second TCI state.

4. The method according to claim 3, further comprising: Receiving a first reference signal (RS) from the first TRP according to the first TCI state; And Receiving a second RS from the second TRP according to the second TCI state.

5. The method according to claim 4, wherein the first RS is a channel state information RS, and the first RS is received during a first symbol, the method further comprising: Receiving control information from the first TRP during the first symbol; And Demodulating the control information using the first RS.

6. The method according to claim 3, further comprising: Transmitting a first reference signal (RS) to the first TRP according to the first TCI state; And Transmitting a second RS to the second TRP according to the second TCI state.

7. The method according to claim 1, further comprising performing uplink transmissions to the first TRP and to the second TRP according to the high-speed moving operation mode.

8. A processor, the processor comprising: An integrated circuit configured to perform operations including: Determining that three conditions for entering a high-speed moving operation mode are satisfied, wherein the three conditions are: A user equipment (UE) is moving rapidly between a first transmission and reception point (TRP) and a second TRP; Radio resource control (RRC) has not configured a repetition scheme for the UE; And One or three code division multiplexing groups are indicated for the UE in the antenna port field; and In response to the determination, entering the high-speed moving operation mode.

9. The processor according to claim 8, wherein the high-speed moving operation mode includes a single downlink control information (DCI) multi-TRP mode.

10. The processor according to claim 8, wherein according to the high-speed moving operation mode, a transmission configuration indication (TCI) code point is configured, wherein the TCI code point indicates a first TCI state and a second TCI state.

11. The operations of the processor according to claim 10 further comprise: Receiving a first reference signal (RS) from the first TRP according to the first TCI state; And Receive a second RS from the second TRP according to the second TCI state.

12. The processor according to claim 11, wherein the first RS is a channel state information RS, and the first RS is received during a first symbol, and the operation further includes: Receiving control information from the first TRP during the first symbol; And Demodulating the control information using the first RS.

13. The processor according to claim 10, the operation further includes: Transmitting a first reference signal (RS) to the first TRP according to the first TCI state; And Transmitting a second RS to the second TRP according to the second TCI state.

14. The processor according to claim 8, wherein the operation further comprises: Perform uplink transmissions to the first TRP and to the second TRP according to the high-speed moving operation mode.

15. A method for wireless communication, the method includes: At a cellular network: Establish communication with a user equipment device (UE); Determine that three conditions for entering a high-speed moving operation mode regarding the UE are satisfied, wherein the three conditions are: The UE is moving rapidly between a first transmission and reception point (TRP) and a second TRP; The radio resource control (RRC) does not configure a repetition scheme for the UE; And One or three code division multiplexing groups are indicated for the UE in the antenna port field; and In response to the determination, enter the high-speed moving operation mode regarding the UE.

16. The method according to claim 15, wherein the high-speed moving operation mode includes: Causing the first TRP to transmit a first demodulation reference signal (DMRS) to the UE on a first time / frequency resource, wherein the first time / frequency resource is within a first time slot, and the first DMRS is UE-specific; And Causing the second TRP to transmit a second DMRS to the UE on a second time / frequency resource, wherein the second time / frequency resource is within the first time slot and is different from the first time / frequency resource, and the second DMRS is UE-specific; Causing the first TRP to transmit first data to be demodulated using the first DMRS to the UE; And Causing the second TRP to transmit second data to be demodulated using the second DMRS to the UE, wherein the second data is a copy of the first data.

17. The method according to claim 16, wherein the first time / frequency resource is a time / frequency resource associated with DMRS transmitted to a second UE not determined to be moving rapidly.

18. The method according to claim 17, further includes: Causing at least one of the first TRP or the second TRP to transmit an indication of the second time / frequency resource to the UE.

19. The method according to claim 18, wherein the indication includes an indication of the offset of the second time / frequency resource relative to the first time / frequency resource.

20. The method according to claim 17, wherein the method further includes: Split the time / frequency resources associated with the DMRS transmitted to the second UE not determined to be moving fast, wherein the second time / frequency resources and the first time / frequency resources are separate subsets of the time / frequency resources associated with the DMRS transmitted to the UE not determined to be moving fast.

21. The method according to claim 16, wherein the first time / frequency resources are associated with a first code division multiplexing (CDM) group, and the second time / frequency resources are associated with a second CDM group.

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