Multi-Input Multi-Output (MIMO) Enhancement for High-Speed Mobility

Abstract

The present disclosure relates to techniques for performing wireless communications by rapidly moving user equipment devices communicating with a network. The UE may adapt communication techniques in response to the UE's movement. For example, reference signals may be transmitted by the UE to additional transmission / reception points and / or using different configurations. Similarly, the UE may receive reference signals from additional transmission / reception points.

Description

Technical Field

[0001] This application relates to wireless communication and includes adapting communication procedures of base stations and network elements in a wireless communication system to user equipment devices moving at high speed.

Background Art

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

[0003] Mobile electronic devices generally may take the form of smartphones or tablets carried by users. Wearable devices (also called accessory devices) are a newer form of mobile electronic devices, and one example is a smartwatch. In addition, low-cost and low-complexity wireless devices intended for stationary or mobile deployments are also increasing rapidly as part of the deployment of the "Internet of Things." In other words, there are an increasingly wide range of desired device complexities, capabilities, traffic patterns, and other characteristics. Generally, it would be desirable to recognize and provide improved support for a wide range of desired wireless communication characteristics. One characteristic could be, for example, the high-speed movement of electronic devices on high-speed trains or other forms of high-speed transportation. Therefore, improvements in this field are desired.

Summary of the Invention

[0004] In particular, embodiments of systems, apparatuses, and methods for performing radio resource control connection procedures for moving a wireless device at high speed in a wireless communication system are presented herein.

[0005] As described above, the number of use cases for wireless networks communicating with different classes of user equipment devices (UEs) having widely variable capabilities and usage expectations is increasing. One direction in the expansion of possible use cases supported by wireless communication techniques may include increasing the use of wireless networks by UEs moving at high speeds. Wireless communication may be affected by high-speed movement, including, for example, due to different channel characteristics observed by different transmit and receive points (TRPs) along the route of a high-speed moving UE. For example, a UE moving along a high-speed train route may experience / demonstrate different characteristics with respect to TRPs in front of and behind the UE.

[0006] Accordingly, the techniques described herein include techniques for a UE (e.g., communicating with a network) to adapt communication techniques to such high-speed movement. For example, a UE may receive reference signals from multiple TRPs and use them to demodulate data and / or control signals from the TRPs. In another example, a UE may update a reference signal configuration in response to flexible signaling. In another example, the concepts and procedures of spatial relation and / or quasi-collocation may be adapted to support high-speed moving UEs. Different transmission configurations may be used by different TRPs, and the transmission configurations may be signaled flexibly.

[0007] Furthermore, the definition of spatial relation may be extended to include a frequency offset. A UE may transmit reference signals based on the spatial relation and / or based on an absolute channel number / frequency.

[0008] Furthermore, to support such high-speed movement, a new operating mode for the UE may be created. For example, the new mode may be a type of single downlink control information (DCI), multi-TRP mode. The new mode may include using multiple transmission configurations.

[0009] The techniques described herein can be implemented in and / or used with several different types of devices including, but not limited to, a cellular phone or smartphone (e.g., iPhone®, Android™-based phone), a tablet computer (e.g., iPad®, Samsung Galaxy®), a portable game device (e.g., Nintendo DS™, PlayStation Portable®, Gameboy Advance®, iPhone®), a wearable device (e.g., smartwatch, smart glasses), a laptop, a PDA, a portable Internet device, a music player, a data storage device, other handheld devices, a vehicle, an automobile, an unmanned aerial vehicle (e.g., drone) and an unmanned aerial controller, other cellular network infrastructure devices, a server, and various other computing devices.

[0010] The summary of the invention is intended to provide some brief overviews of some of the subject matter described in this document. Thus, it is to be understood that the above features are merely examples and should not be construed as narrowing the scope or spirit 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] The subject matter of the present invention can be better understood when the following detailed description of the embodiments is considered in conjunction with the following drawings.

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[0018] The features described in this specification have room for various modifications and alternative forms. At the same time, specific embodiments are shown in the drawings as examples and will be described in detail in this specification. However, it should be understood that the drawings and their detailed descriptions are not intended to limit to the specific forms disclosed, but rather are intended to encompass all modifications, equivalents, and alternatives within the spirit and scope of the subject matter defined by the appended claims.

Mode for Carrying Out the Invention

[0019] Acronyms and Abbreviations The following acronyms and abbreviations are used in this disclosure.

[0020] 3GPP: 3rd Generation Partnership Project

[0021] 3GPP2: 3rd Generation Partnership Project 2

[0022] GSM: Global System for Mobile Communications

[0023] UMTS: Universal Mobile Telecommunications System

[0024] LTE: Long Term Evolution

[0025] IoT: Internet of Things

[0026] QCL: Quasi-Co-Location

[0027] TCI: Transmit Configuration Indication

[0028] RRC: Radio Resource Control

[0029] MAC: Medium Access Control

[0030] CE: Control Element

[0031] Tx: Transmission (or Transmit)

[0032] Rx: Reception (or Receive)

[0033] RS: Reference Signal

[0034] CSI: Channel State Information Glossary

[0035] The following are the definitions of the terms used in this disclosure.

[0036] Memory medium - Any of various types of non-transitory memory devices or storage devices. The term "memory medium" is intended to include, for example, installation media such as CD-ROMs, floppy disks, or tape devices; computer system memory or random access memory such as DRAM, DDR RAM, SRAM, EDO RAM, Rambus RAM; magnetic media such as flash, hard drives, or non-volatile memory such as optical storage; registers, or other similar types of memory elements. The memory medium may also include other types of non-transitory memory, or combinations thereof. Additionally, the memory medium may be located in a first computer system on which the program is executed, or in a second different computer system connected to the first computer system via a network such as the Internet. In the latter case, the second computer system can provide program instructions to the first computer for execution. The term "memory medium" may include two or more memory media that can exist in different locations, for example, in different computer systems connected via a network. The memory medium may store program instructions that can be executed by one or more processors (e.g., embodied as a computer program).

[0037] Carrier medium - The memory medium as described above, as well as physical transmission media such as buses, networks, and / or other physical transmission media that transmit signals such as electrical signals, electromagnetic signals, or digital signals.

[0038] Programmable hardware elements - include various hardware devices comprising a plurality of programmable functional blocks connected via a programmable interconnect. Examples include Field Programmable Gate Arrays (FPGAs), Programmable Logic Devices (PLDs), Field Programmable Object Arrays (FPOAs), and Complex Programmable Logic Devices (CPLDs). Programmable functional blocks can range from fine-grained ones (combinational logic or look-up tables) to coarse-grained ones (arithmetic logic units or processor cores). Programmable hardware elements are also sometimes referred to as "reconfigurable logic".

[0039] Computer systems - any of various types of computing or processing systems, including personal computer systems (PCs), mainframe computer systems, workstations, network devices, Internet devices, personal digital assistants (PDAs), television systems, grid computing systems, or other devices or combinations of devices. In general, the term "computer system" can be defined broadly to include any device (or combination of devices) having at least one processor that executes instructions from a memory medium.

[0040] 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 (registered trademark), Android (trademark)-based phones), tablet computers (e.g., iPad (registered trademark), Samsung Galaxy (registered trademark)), portable game devices (e.g., Nintendo DS (trademark), PlayStation Portable (trademark), Gameboy Advance (registered trademark), iPhone (registered trademark)), wearable devices (e.g., smartwatches, smart glasses), laptops, PDAs, portable Internet devices, music players, data storage devices, other handheld devices, vehicles, automobiles, unmanned aerial vehicles (e.g., drones), unmanned aerial controllers, etc. In general, the terms "UE" or "UE device" can be broadly defined to include any electronic device, computing device, and / or telecommunication device (or combination of devices) that can be easily carried by a user and is capable of wireless communication.

[0041] 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 may be stationary or fixed in a location. A UE is an example of a wireless device.

[0042] 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 may be portable (or mobile), or it may be stationary or fixed in a particular location. A wireless device is an example of a communication device. A UE is another example of a communication device.

[0043] Base station - The term "base station" has its full ordinary meaning and includes at least a radio communication station installed at a fixed location and used for communication as part of a radiotelephone system.

[0044] Link budget limited - Includes its full ordinary meaning and includes at least the characteristics of a wireless device (e.g., UE) that exhibits limited communication capabilities or limited power with respect to a device where the link budget is not limited or with respect to a device for which a radio access technology (RAT) standard has been developed. A wireless device with a limited link budget may experience relatively limited receiving and / or transmitting capabilities, which may be due to one or more factors such as the design of the device, the size of the device, the size of the battery, the size or design of the antenna, the transmit power, the receive power, the current transmission medium state, and / or other factors. Such a device may be referred to herein as a "link budget limited" (or "link budget constrained") device. A device may be inherently link budget limited due to its size, battery power, and / or transmit / receive power. 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, a device may not be inherently link budget limited, e.g., 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, e.g., a smartphone at the edge of a cell. Note that the term "link budget limited" includes or encompasses power limitations, and thus a device with limited power can be considered a link budget limited device.

[0045] Refers to various elements or combinations of elements capable of performing functions within a processing element (or processor) - within a device, for example, within a user equipment device or within a cellular network device. A processing element may include, for example, a processor and associated memory, portions or circuits of individual processor cores, entire processor cores, individual processors, processor arrays, circuits such as application specific integrated circuits (ASICs), programmable hardware elements such as field programmable gate arrays (FPGAs), and any of various combinations of the foregoing.

[0046] Automatically - where user input causes a computer system (e.g., software executed by a computer system) or device (e.g., circuit mechanism, programmable hardware element, ASIC, etc.) to perform those actions or operations without directly specifying or executing the action or operation. Thus, the term "automatically" is contrasted with actions that are manually performed or specified by the user, where the user provides input to directly execute the action. An automatic procedure can be initiated by input provided by the user, but subsequent actions that are "automatically" performed are not specified by the user. That is, each action performed is not "manually" specified by the user. For example, a user filling out an electronic form by selecting each field and providing input to specify information (e.g., by typing information, selecting a checkbox, making radio selections, etc.) is considered a manual filling out of the form, although the computer system must update the form in response to the user action. The form may be filled out automatically by a computer system, where the computer system (e.g., software executed on the computer system) analyzes the fields of the form and fills out the form without user input specifying the responses to the fields. As described above, the user can initiate the automatic filling out of the form but is not involved in the actual filling out of the form (e.g., the user does not manually specify responses to the fields; rather, the responses are automatically completed). This specification provides various examples of actions that are automatically performed in response to actions taken by the user.

[0047] configured to - Various components can be described as being "configured to" perform a task. In such a context, "configured to" is a broad description generally meaning "having a structure" that performs a task or tasks during operation. Thus, a component may be configured to perform a task even when the component is not currently performing the task (e.g., a set of conductors may be configured to electrically connect a module to another module even when the two modules are not connected). In some contexts, "configured to" may be a broad description of a structure generally meaning "having a circuit" that performs a task or tasks during operation. Thus, a component may be configured to perform a task even when the component is not currently on. Generally, a circuit forming the structure corresponding to "configured to" may include a hardware circuit.

[0048] In the description herein, for convenience, various components can be described as performing a task or tasks. Such descriptions should be construed to include the phrase "configured to." It is clearly intended that the description of a component configured to perform one or more tasks does not apply the interpretation of that component under paragraph 6 of 35 U.S.C. § 112. Figures 1 - 2: Wireless Communication System

[0049] FIG. 1 shows an example of a wireless cellular communication system. FIG. 1 represents one of many possibilities, and it should be noted that, if desired, the features of the present disclosure may be implemented in any of various systems. For example, the embodiments described herein may be implemented in any type of wireless device.

[0050] As shown in the figure, an exemplary wireless communication system includes a cellular base station 102 that communicates via a transmission medium, along with one or more wireless devices 106A, 106B, etc. and an accessory device 107. The wireless devices 106A, 106B, and 107 may be user devices that may be referred to herein as "user equipment" (UE) or UE devices.

[0051] The base station 102 can be a base transceiver station (BTS) or a cell site, and may include hardware and / or software that enables wireless communication with the UE devices 106A, 106B, and 107. If the base station 102 is implemented in the context of LTE, it may alternatively be referred to as an "eNodeB" or "eNB". If the base station 102 is implemented in the context of 5G NR, it may alternatively be referred to as a "gNodeB" or "gNB". Also, the base station 102 may be equipped to communicate with a network 100 (e.g., among various possibilities, a core network of a cellular service provider, a telecommunications network such as a public switched telephone network (PSTN), and / or the Internet). Therefore, the base station 102 can facilitate communication between the UE devices 106 and 107, and / or between the UE devices 106 / 107 and the network 100. Also, as used herein, from the perspective of the UE, the base station may be regarded as representing the network as far as the UL (uplink) communication and DL (downlink) communication of the UE are concerned. Thus, a UE communicating with one or more base stations in the network may be interpreted as a UE communicating with the network.

[0052] In other implementations, the base station 102 may be configured to provide communication through one or more WLAN protocols such as 802.11a, b, g, n, ac, ad, and / or ax, or through one or more other wireless technologies such as an access point that supports LTE in the license-exempt band (LAA).

[0053] The communication area (or coverage area) of base station 102 is sometimes called a "cell". Base station 102 and UE 106 / 107 may be configured to communicate via a transmission medium using any of various radio access technologies (RATs) or wireless communication technologies such as GSM, UMTS (WCDMA (registered trademark), TDS-CDMA), LTE, LTE-Advanced (LTE-A), NR, HSPA, 3GPP2 CDMA2000 (e.g., 1xRTT, 1xEV-DO, HRPD, eHRPD), Wi-Fi (trademark).

[0054] Base station 102 and other similar base stations (not shown) operating according to one or more cellular communication technologies may thus be provided as a network of cells that can provide continuous or nearly continuous overlapping services to UE devices 106A - N, 107, and similar devices across a geographic area via one or more cellular communication technologies.

[0055] Note that in at least some examples, UE devices 106 / 107 can communicate using any 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 (trademark), one or more global satellite navigation systems (GNSS, e.g., GPS or GLONASS), and one and / or two or more mobile television broadcast standards (e.g., ATSC-M / H). Other combinations of wireless communication technologies (including three or more wireless communication technologies) are also possible. Similarly, in some examples, UE devices 106 / 107 may be configured to communicate using only a single wireless communication technology.

[0056] UE106A and 106B may include handheld devices such as smartphones or tablets, and / or may include any of various types of devices having a cellular communication function. For example, one or more of UE 106A and 106B may be wireless devices intended for fixed or nomadic deployment, such as appliances, measurement devices, control devices, etc. UE 106B may be configured to communicate with a UE device 107, sometimes referred to as accessory device 107. Accessory device 107 may be any of various types of wireless devices, typically a wearable device with a smaller form factor, and may have limited battery, output power, and / or communication capabilities compared to UE106. As one common example, UE106B may be a smartphone carried by a user, and accessory device 107 may be a smartwatch worn by the same user. UE106B and accessory device 107 may communicate using any of various short-range communication protocols such as Bluetooth or Wi-Fi. In some cases, UE106B and accessory device 107 may perform direct peer-to-peer communication using Proximity Services (ProSe) techniques, for example, in a manner supported by a cellular base station. For example, such ProSe communication may be performed as part of a relay link to support a radio resource control connection between accessory device 107 and BS102, according to various embodiments described herein.

[0057] UE106B may also be configured to communicate with UE106A. For example, UE106A and UE106B may be capable of performing direct device-to-device (D2D) communication. D2D communication may be supported by cellular base station 102 (e.g., BS102 may facilitate discovery, among various possible forms of assistance), or may be performed in a way not supported by BS102. For example, it may be the case where UE106A and UE106B are capable of configuring and performing D2D communication (e.g., including discovery communication) with each other even when they are outside the coverage of BS102 and other cellular base stations.

[0058] BS 102 may control one or more transmit receive points (TRPs) and may use the TRPs to communicate with the UE. The TRPs may be co-located with the BS and / or at separate physical locations.

[0059] FIG. 2 shows an exemplary BS 102 communicating with a UE device 106, and the UE device 106 communicates with an accessory device 107. The UE device 106 and the accessory device 107 can be any of a mobile phone, a tablet, or any other type of handheld device, a smartwatch or other wearable device, a media player, a computer, a laptop, an unmanned aerial vehicle (UAV), an unmanned aerial controller, a vehicle, or substantially any type of wireless device. In some embodiments, the accessory device is designed to have low cost and / or low power consumption and can benefit from the use of a relay link with the UE device 106 (and / or another companion device) to support communication with the BS 102. A device that utilizes a relay link with another wireless device to communicate with a cellular base station, as in the scenario shown in FIG. 2, may be referred to herein as a remote wireless device, a remote device, or a remote UE device, and a wireless device that provides such a relay link may be referred to herein as a relay wireless device, a relay device, or a relay UE device. According to some embodiments, such a BS 102, UE 106, and accessory device 107 may be configured to execute radio resource control procedures for a remote wireless device according to various techniques described herein.

[0060] UE106 and / or accessory device 107 may each include a device or integrated circuit, referred to as a cellular modem, to facilitate cellular communication. The cellular modem may include one or more processors (processing elements) configured to execute program instructions stored in memory, and / or various hardware components described herein. UE106 and / or accessory device 107 can each execute any of the method embodiments described herein by executing such stored instructions. Alternatively or in addition, UE106 and / or accessory device 107 may include programmable hardware elements such as a Field Programmable Gate Array (FPGA), integrated circuit, and / or any of the method embodiments described herein, or any arbitrary portion of any of the method embodiments described herein (e.g., individually or in combination), such as any of various other possible hardware components configured to execute. The cellular modems described herein can be used in a UE device as defined herein, a wireless device as defined herein, or a communication device as defined herein. The cellular modems described herein can also be used in a base station or other similar network-side device.

[0061] UE106 and / or accessory device 107 may include one or more antennas for communicating using one or more wireless communication protocols compliant with one or more RAT standards. In some embodiments, one or both of UE106 or accessory device 107 may be configured to communicate using a single shared radio. The shared radio may be coupled to a single antenna or (e.g., for MIMO) multiple antennas to perform wireless communication. Generally, the radio may include any combination of a baseband processor, analog RF signal processing circuitry (including, e.g., filters, mixers, oscillators, amplifiers, etc.), or digital processing circuitry (e.g., for digital modulation and other digital processing). Similarly, the radio may implement one or more receive and transmit chains using the above hardware.

[0062] Alternatively, UE106 and / or accessory device 107 may include two or more radios. For example, in some embodiments, UE106 and / or accessory device 107 may include separate transmit and / or receive chains (including, e.g., separate antennas and other radio components) for each wireless communication protocol that UE106 is configured to use for communication. As a further possibility, UE106 and / or accessory device 107 may include one or more radios shared among multiple wireless communication protocols and one or more radios exclusively used by a single wireless communication protocol. For example, UE106 and / or accessory device 107 may include a shared radio for communicating using either LTE or CDMA2000 1xRTT (or LTE or NR or LTE or GSM) and individual radios for communicating using each of Wi-Fi and BLUETOOTH®. Other configurations are possible. Figure 3 - Block diagram of UE device

[0063] FIG. 3 shows one possible block diagram of a UE device such as UE device 106 or 107. As shown in the figure, UE device 106 / 107 may include a system on chip (SOC) 300 that may include various parts for various purposes. For example, as shown in the figure, SOC 300 may include a processor(s) 302 capable of executing program instructions for UE device 106 / 107 and a display circuit 304 capable of performing graphic processing and providing a display signal to a display 360. SOC 300 may also include a motion sensing circuit 370 capable of detecting the motion of UE 106 using, for example, a gyroscope, an accelerometer, and / or any of various other motion sensing components. Processor(s) 302 may also be coupled to a memory management unit (MMU) 340 configured to receive addresses from processor(s) 302 and translate those addresses to locations within a memory (e.g., memory 306, read only memory (ROM) 350, flash memory 310), and / or may also be coupled to other circuits or other devices such as display circuit 304, radio 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(s) 302.

[0064] As shown in the figure, SOC 300 may be coupled to various other circuits of UE 106 / 107. For example, UE 106 / 107 may include various types of memory (e.g., including NAND flash 310), a connector interface 320 (e.g., for coupling to a computer system, dock, charging station, etc.), a display 360, and a wireless communication circuit 330 (e.g., for LTE, LTE-A, NR, CDMA2000, Bluetooth, Wi-Fi, NFC, GPS, etc.).

[0065] UE devices 106 / 107 may include at least one antenna, and in some embodiments, a plurality of antennas 335a and 335b, for performing wireless communication with a base station and / or other devices. For example, UE devices 106 / 107 can use antennas 335a and 335b to perform wireless communication. As described above, UE devices 106 / 107 may be configured to wirelessly communicate using multiple wireless communication standards or radio access technologies (RATs) in some embodiments.

[0066] Wireless communication circuitry 330 may include Wi-Fi logic 332, a cellular modem 334, and Bluetooth logic 336. Wi-Fi logic 332 is for enabling UE devices 106 / 107 to perform Wi-Fi communication on an 802.11 network. Bluetooth logic 336 is for enabling UE devices 106 / 107 to perform Bluetooth communication. Cellular modem 334 can be a low-power cellular modem capable of performing cellular communication according to one or more cellular communication technologies.

[0067] As described herein, the UE106 / 107 may include hardware and software components for implementing embodiments of the present disclosure. The processor(s) 302 of the UE device 106 / 107 may be configured to execute some or all of the methods described herein, for example, by executing program instructions stored in a memory medium (e.g., a non-transitory computer-readable memory medium). In other embodiments, the processor(s) 302 may be configured as a programmable hardware element such as a field-programmable gate array (FPGA) or as an application-specific integrated circuit (ASIC). Further, the processor(s) 302 may be coupled to and / or interoperate with other components shown in FIG. 3 to execute radio resource control procedures for remote wireless devices according to various embodiments disclosed herein. The processor(s) 302 may also implement various other applications and / or end-user applications operating on the UE106. Alternatively, or in addition, one or more components of the wireless communication circuitry 330 (e.g., cellular modem 334) of the UE device 106 / 107 may be configured to execute some or all of the methods described herein using, for example, a processor that executes program instructions stored in a memory medium (e.g., a non-transitory computer-readable memory medium), a processor configured as an FPGA (field-programmable gate array), and / or dedicated hardware components that may include an ASIC (application-specific integrated circuit). FIG. 4 - Block Diagram of Base Station

[0068] FIG. 4 shows an exemplary block diagram of base station 102 according to some embodiments. Note that the base station in FIG. 4 is merely an example of a possible base station. As shown in the figure, base station 102 may include a processor(s) 404 capable of executing program instructions for base station 102. The processor(s) 404 may also be coupled to a memory management unit (MMU) 440, which is configured to receive addresses from the processor(s) 404 and convert those addresses to locations within a memory (e.g., memory 460 and read-only memory (ROM) 450) or other circuits or devices.

[0069] Base station 102 may include at least one network port 470. Network port 470 is configured to couple to a telephone network and may provide access to that telephone network to a plurality of devices such as UE devices 106 / 107 as described above with respect to FIGS. 1 and 2.

[0070] Network port 470 (or an additional network port) may also or alternatively be configured to couple to a cellular network such as, for example, the core network of a cellular service provider. This core network may be able to provide mobility-related services and / or other services to a plurality of devices such as 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) and / or a packet data network gateway (PGW) for providing an external data connection to, for example, the Internet. In some cases, network port 470 may couple to the telephone network via the core network and / or the core network may provide the telephone network (e.g., among other UE devices served by a cellular service provider).

[0071] The base station 102 may include at least one antenna 434, and possibly multiple antennas. The antenna(s) 434 may be configured to operate as a wireless transceiver and may be further configured to communicate with the UE devices 106 / 107 via the radio 430. The antenna(s) 434 communicate with the radio 430 via the communication chain 432. The communication chain 432 may be a receive chain, a transmit chain, or both. The radio 430 can be configured to communicate according to various wireless communication standards including, but not limited to, LTE, LTE-A, NR, GSM, UMTS, CDMA2000, Wi-Fi, etc.

[0072] The base station 102 can be configured to perform wireless communication using multiple wireless communication standards. In some cases, the base station 102 can include multiple radios, which can enable the base station 102 to communicate according to multiple wireless communication technologies. For example, as one possibility, the 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 a case, the base station 102 can operate as both an LTE base station and a Wi-Fi access point. As another possibility, the base station 102 can include a multi-mode radio, which can perform communication according to any of multiple wireless communication technologies (e.g., LTE and NR, LTE and Wi-Fi, LTE and UMTS, LTE and CDMA2000, UMTS and GSM, etc.).

[0073] As further described herein below, BS102 can include hardware and software components for implementing or supporting the implementation of the features described herein. According to some embodiments, the processor 404 of base station 102 may be configured to implement some or all of the methods described herein, for example, by executing program instructions stored in 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 a field programmable gate array (FPGA), or as an application specific integrated circuit (ASIC), or as a combination thereof. Alternatively (or in addition), the processor 404 of BS102, together with one or more of the other components 430, 432, 434, 440, 450, 460, 470, may be configured to implement, and / or support the implementation of, wireless resource control procedures for remote wireless devices according to various embodiments disclosed herein, and / or any of various others of the features described herein. Figure 5 - Communication Flow Diagram

[0074] High-Speed Train (HST) is a deployment scenario of great interest to several operators, especially those from countries / regions (e.g., China) where HST systems are deployed. As a result, HST enhancements can be part of the further enhanced (Fe) multiple-input multiple-output (MIMO) (FeMIMO) in Release 17. For example, a UE can move between two transmit receive points (TRPs) in an HST scenario, or other scenarios involving high-speed movement. The UE can observe a very high positive Doppler shift from one TRP and a very high negative Doppler shift from the other TRP. As a result, the composite channel can change rapidly. For example, Doppler shifts close to 4 kHz or higher may be observed. Such shifts can potentially reduce the channel capacity and / or make it very difficult for the UE to perform accurate channel estimation.

[0075] 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 each TRP, although more than three TRPs are also 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 may determine the Doppler shift for each TRP for compensation.

[0076] FIG. 5 is a communication flow diagram illustrating an exemplary method for communicating in the case of a UE moving at high speed, according to some embodiments. The method of FIG. 5 may mitigate some communication challenges associated with high-speed movement. In various embodiments, some of the elements of the method shown in the figure may be executed simultaneously, may be executed in an order different from the order shown in the figure, may be replaced by other method elements, or may be omitted. Additional method elements may be executed as necessary.

[0077] Aspects of the method of FIG. 5 may be performed by a UE, such as UE 106 or 107, a cellular network, one or more transmit receive points (TRPs), and / or one or more BSs 102, as shown and described in the figures, or more generally, may be performed in conjunction with any of the computer systems, circuits, elements, components, or devices shown in the figures, as needed, among other devices. For example, one or more processors (or processing elements) (e.g., among various possibilities, a 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 a UE, a network element, and / or a BS to perform some or all of the illustrated method elements. Although at least some of the elements of the method of FIG. 5 are described as relating to the use of communication techniques and / or features associated with LTE standard documents, NR standard documents, and / or 3GPP (registered trademark) specifications, such descriptions are not intended to limit the present disclosure, and it should be noted that aspects of the method of FIG. 5 may be used in any suitable wireless communication system as needed. As shown in the figures, the method may operate as follows.

[0078] According to some embodiments, the UE can establish communication with the network via two TRPs (TRP501a and TRP501b) (502). It will be appreciated that according to various embodiments, the TRP can be controlled by a single BS or different BSs. The UE may be moving. For example, the UE may be moving towards one of the TRP501s and away from the other TRP501. For example, the UE may be moving on a high-speed train (or in a car, drone, UAV, or other vehicle) along a route (such as a railway line, highway, path, etc.), and the TRP501a and TRP501b may be along or near the route. Thus, the UE can approach one TRP501 and move away from the other TRP501. Thus, the signals exchanged between the UE and the TRP may be affected by the movement. For example, the signal may exhibit a Doppler shift or frequency offset due to the movement of the UE.

[0079] According to some embodiments, the network (such as the control BS102 and / or either or both of the TRP501a and / or TRP501b) and / or the UE can determine that the UE is moving at high speed (504). For example, the network and / or the TRP501 can determine that the UE is moving at high speed based on any or all of wireless measurements (such as reference signals or other communications transmitted by the UE), reports from the UE (such as wireless measurements taken by the UE and / or based on the UE's motion sensing characteristics, such as those from a global navigation satellite system like an accelerometer, motion sensor, gyroscope, GPS, etc.), knowledge of the UE's recent movement, and / or knowledge of transport information (such as train schedules, highway routes, knowledge of the movement of other UEs (such as multiple UEs in the same train / vehicle), etc.). Thus, in some embodiments, the network can be configured to infer the movement of the UE from various different measurements or inputs. The UE can similarly determine its movement based on, for example, similar information.

[0080] In some embodiments, the UE may explicitly indicate to the network information about its movement. For example, the UE may indicate to the network that it is on a high-speed train or moving at high speed in some other way. Based on receiving such an indication, the network may determine that the UE is moving at high speed.

[0081] According to some embodiments, the network and / or the UE can adapt the communication technique based on the movement of the UE (506). Such adaptation may include techniques for coordinating communication between two TRPs, for example, the TRP that the UE is moving towards and the TRP that the UE is moving away from, among other possibilities. Such adaptation can include enhancements in any of the following areas.

[0082] For example, enhancements for downlink data transmission and reception via reference signals (RS) used for demodulation. For example, the demodulation reference signal (DMRS) associated with the physical downlink shared channel (PDSCH) can be scheduled, transmitted, and / or processed separately. For example, both TRPs can transmit the DMRS or other RS to the UE for use by the UE, for example, while communicating with the UE simultaneously. The RS transmitted by different TRPs can be coordinated and orthogonalized in any of various ways (e.g., time division, frequency division, code division, and / or port division). For example, both TRPs can transmit the UE-specific RS to the UE during the first slot (or frame or other period), for example, in the same or different symbols of the first slot.

[0083] Enhancement for the transmission of control information to the UE, such as downlink control information (DCI) transmission. For example, reference signals (RSs) associated with the physical downlink control channel (PDCCH) (e.g., DMRS and / or other RSs) can be scheduled, transmitted, and / or processed differently, e.g., for enhanced reliability. For example, both TRPs can transmit RSs to the UE, e.g., for use by the UE communicating with the TRPs simultaneously. Multiple transmission configuration indication (TCI) states can be provided to the UE and used for communication between the UE and the network, and / or new quasi-colocation (QCL) types can be defined, provided to the UE, and used for communication between the UE and the network.

[0084] Enhancement of the spatial relationship for uplink RSs. For example, the configuration for uplink RSs such as sounding RSs (SRSs) used for UL power control or DL path loss RSs can be adapted.

[0085] New operation modes (e.g., HST mode). For example, the high-speed movement mode can be created as a special case (e.g., or a variation thereof) of the single downlink control information (DCI) multi-TRP mode. Such a new mode can 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).

[0086] According to some embodiments, the UE and the network (e.g., TRP501a and / or TRP501b) can communicate using adapted communication techniques (508). For example, while the UE is moving at high speed between TRP501a and TRP501b, the UE and the network can exchange data and / or control information using adapted communication techniques. The data and / or control information can be exchanged in the UL and / or DL directions.

[0087] The UE and the network can adapt the communication technique and continue to communicate as the UE moves. For example, when the UE passes through one TRP, the relationship with the TRP (e.g., Doppler shift, frequency offset, spatial relationship, QCL, and / or other parameters) may change. For example, the frequency offset regarding the TRP may change sign when the UE passes through the TRP.

[0088] Further examples and information regarding various types of adaptation of the UE to high-speed movement (e.g., as introduced above regarding 506) are described below. It will be understood that according to some embodiments, these examples may be used together (e.g., in any of various combinations) and / or separately. Downlink data enhancement

[0089] When the UE moves very fast towards or further away from a TRP, the UE may experience a large frequency offset regarding a Doppler shift that may be linearly proportional to the UE speed and the carrier frequency. Thus, at high frequencies and when the UE moves very fast, for example, approaching or exceeding 350 km / hr as in a high-speed train (HST), the frequency offset (Doppler shift) caused by the UE movement may be close to or exceed 2 kHz, and multiple cycles of the channel phase and amplitude will change per millisecond, which may be different from typical multi-TRP operation. Due to the high-speed movement in the HST scenario, it may be difficult for the UE to cope with the rapidly changing fluctuations.

[0090] FIG. 6 shows downlink data enhancement according to some embodiments (e.g., via PDSCH DMRS enhancement). As shown, UE 106 can move between two TRPs, TRP1 and TRP2 (e.g., on a train). According to some embodiments, it will be understood that the TRPs can be controlled by a single BS102 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 temporally overlapping (e.g., simultaneous) communication with both TRPs. In other words, the UE may maintain communication with both TRPs simultaneously. For example, both TRPs can transmit RSs to the UE in the same slot. Different TRPs can use the same or different symbols in the same slot.

[0091] According to some embodiments, the TRP can transmit DMRS or other RS according to a non-single frequency network (SFN) mode. For example, the DMRSs from different TRPs can be transmitted to a fast-moving UE communicating with both TRPs (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) using different DMRS ports, and / or (4) using different orthogonal codes (e.g., code division multiplexing (CDM)). For example, at 504, in response to determining that the UE is moving fast, the network can determine to transmit DMRS (and / or other RS) for use by the UE from multiple TRPs, e.g., simultaneously, or repeatedly or alternately. The UE can use the DMRS (and / or other RS) when demodulating the downlink data and / or control information transmitted by the corresponding TRP.

[0092] In some embodiments, the RSs (e.g., DMRS) transmitted to the UE from different TRPs may be UE-specific. In other words, a particular RS may be transmitted to the UE based on any of a variety of factors, such as the movement of the UE, the scheduled communication between the UE and the TRP, and the radio measurements of the channel between the UE and the TRP. According to some embodiments, the RSs transmitted to the UE from different TRPs may be the same or different.

[0093] In some embodiments, unlike the current DMRS design, different TRPs may transmit different RS (e.g., DMRS) patterns to the UE. Thus, the UE can separate the RSs from different TRPs. Such a distinction between RSs can reduce channel variations caused by high UE movement speeds and improve UE channel estimation quality. Thus, according to some embodiments, the RSs can be both UE-specific and TRP-specific.

[0094] As shown in FIG. 7, the DMRSs (e.g., or UE-specific RSs) from different TRPs may be transmitted at different times (e.g., the symbols 0 to 13 of the slot in time are shown horizontally and the frequency domain is shown vertically). For example, the DMRS position (e.g., in time / frequency) of the first TRP (e.g., TRP501a) may be known from existing standards and / or configuration information. The DMRS position (e.g., in time / frequency) of the second TRP (e.g., TRP501b) may be indicated via further control information (e.g., radio resource control (RRC), media access control (MAC) control element (CE), and / or downlink control information (DCI), etc.). The control information may be transmitted via, among other possibilities, multiple TRPs, or one of the TRPs. For example, both the first and second TRPs may transmit the control information, or only one of the TRPs (e.g., either the first or the second) may transmit the control information. Similarly, the DMRS position of the second TRP may be implicitly determined by the UE.

[0095] For example, the new (e.g., additional) symbol positions for the DMRS of the second (e.g., additional) TRP can be defined in the technical specification, either explicitly or relative to the symbol positions for the DMRS of 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 a specific position for the DMRS (e.g., with respect to symbols and resource elements (REs)). For example, in FIG. 7, the position of the DMRS of TRP2 may be in symbols 1 and 8. Alternatively, the control information can indicate an offset for the DMRS position of the second TRP relative to the first TRP (e.g., in the example of FIG. 7, the position of the DMRS of TRP2 can be offset by one symbol relative to the DMRS of TRP1).

[0096] In some embodiments, existing DMRS symbol positions (e.g., symbols designated for DMRS transmission according to existing specifications and / or control information) can be split between the first TRP and the second TRP when multiple DMRS positions are configured. In other words, if a first number of REs in a slot can be designated (e.g., by previous control information and / or standards) for RS, the first number of REs can be re - split such that one subset of the REs is used for the RS of TRP1 and a second subset of the REs is used for the RS of TRP2. Control information can be used to indicate the re - split of the RS positions when the second RS is configured.

[0097] Although the time positions (e.g., symbols) of the RSs associated with the TRPs are different, it will be understood that the UE is communicating with the TRPs simultaneously. In other words, the time positions overlap and are time - division multiplexed (TDMd). For example, a TRP can transmit RSs in different symbols of the same slot. For example, the first TRP can use one or more first symbols, and the second TRP can use one or more second symbols.

[0098] FIG. 8 shows DMRS transmissions from different TRPs at different frequencies according to some embodiments. The DMRS transmissions in FIG. 8 can be shown using any combination of the techniques described above. For example, the RS positions can be shown explicitly or using an offset. Existing RS positions can be re-divided.

[0099] Another approach for orthogonalizing the RSs of different TRPs can be by code division multiplexing (CDM). For example, DMRSs from different TRPs can be transmitted in different CDM groups. Each CDM group can support up to four ports via orthogonal codes according to some embodiments. Different CDM groups can be orthogonalized via frequency division multiplexing (FDM). Depending on the number of CDM groups configured for the UE, various techniques can be used to orthogonalize the RSs of the TRPs.

[0100] When a single CDM group is configured, there can be one or more (e.g., pre-defined) ports indicated in the CDM group for the DMRS (e.g., or other RS). Thus, one or more ports indicated for the RS can be used for the RS and / or data transmission for one TRP. One or more other ports of the CDM group (e.g., the remaining ports) can be used for the RS and / or data transmission for another TRP. In some embodiments, which port is used for which TRP can be explicitly signaled in the control information or implicitly indicated (e.g., based on scheduling a single TRP on a particular port). For example, when one CDM group is configured (e.g., by DCI) and the DCI (or other control information) indicates the port (or ports) for the DMRS, that port (or ports) can be used for the first TRP and any other port can be used for the DMRS of another TRP. In some embodiments, the data from each TRP may use the same port as the RS from the corresponding TRP.

[0101] When two CDM groups are configured, the DMRS ports within the first CDM group can correspond to one TRP, and the DMRS ports within the second CDM group can correspond to the other TRP. Thus, as shown in FIG. 9, the REs can be split between the two CDM groups (e.g., alternating in this example, but other splits can be used as needed). Each CDM group can be used for DMRS from different TRPs. In the illustrated example, 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 use the DMRS of each TRP (e.g., jointly) to demodulate the corresponding data. For example, if two TRPs transmit replicated data (e.g., TRP2 transmits a copy of the data transmitted by TRP1), the UE can use the combination of DMRS from each TRP to estimate the channel and demodulate the data. Alternatively, if two TRPs transmit different data, the UE can use the DMRS from one TRP to estimate the channel from that TRP and demodulate the data. The data can be transmitted at different frequencies (e.g., simultaneously with the RS), at different times from the RS (e.g., different symbols but potentially the same frequency), and / or using different antenna ports from the RS.

[0102] When three CDM groups are configured, the (one or more) DMRS ports in the first subset of CDM groups (e.g., 1 or 2) may correspond to one TRP, and the DMRS ports in the rest of the CDM groups may correspond to other TRPs. FIG. 10 shows an example with three CDM groups according to some embodiments. CDM group 0 may correspond to the first TRP, and CDM groups 1 and 2 may correspond to the second TRP. In the illustrated example, the REs in CDM group 0 may be used for the DMRS corresponding to the first TRP, and the REs in CDM groups 1 and 2 may be used for the DMRS corresponding to the second TRP. The UE may use the DMRS from both the first and the second TRPs transmitted in CDM groups 0, 1, and 2 (e.g., together if different TRPs transmit replicated data) to decode the data of the PDSCH channel. Alternatively, when different TRPs transmit different data, the UE may, for example, use the DMRS of CDM group 1 to decode the data of CDM group 2 because CDM groups 1 and 2 are transmitted by the same TRP and thus share channel characteristics. Note that it is also possible to split such that CDM groups 0 and 1 correspond to the first TRP and CDM group 2 corresponds to the second TRP.

[0103] In another approach to orthogonalize the RSs, the RSs from different TRPs may be transmitted using different ports. For example, the UE may receive the RSs from different TRPs using different antenna ports.

[0104] In some embodiments, a second antenna port field may be introduced within the DCI. The second antenna port field may be a replica (e.g., a copy) of the existing port field. Thus, the network (e.g., the base station) may separately indicate the antenna port configuration for the RSs from each TRP, e.g., via the DCI. For example, in a DCI message to the UE, the network may indicate the first port for the DMRS of TRP1 and the second port for the DMRS of TRP2.

[0105] In some embodiments, a new table for antenna port field interpretation (e.g., in 38.212) may be introduced. Such a table may specify two different ports for at least some values of the antenna port field (e.g., for different TRPs). Thus, for such antenna port field indications, two sets of DMRS ports can be defined, i.e., one set of DMRS ports for the first TRP and a second set of DMRS ports for the second TRP.

[0106] In some embodiments, the data transmitted from the TRPs (e.g., associated with the RS) may be the same. For example, the first TRP may transmit first data to the UE during a slot. During the same slot (e.g., using any of the orthogonalization techniques described above, e.g., in the same and / or different symbols), the 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 can combine the 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 / second data. Downlink Control Channel Enhancement

[0107] Figures 11 to 15 show aspects of enhancing the reliability of the downlink control channel (e.g., PDCCH) according to some embodiments. According to some embodiments, multiple TRPs can transmit control information to a UE using the same control resource set (CORESET). Similar to the above description of downlink data enhancement, the RSs transmitted by different TRPs can be orthogonalized in various ways, such as frequency division, code division, and / or port division. Therefore, the RS transmitted by a TRP can be used for temporally overlapping (e.g., simultaneous) communication with both TRPs. In other words, the UE may maintain communication with both TRPs simultaneously. For example, both TRPs may transmit UE-specific RS to the same UE in each symbol of the CORESET. Further, as described above, the RS may be TRP-specific, and the UE can distinguish the RSs of different TRPs.

[0108] Furthermore, according to some embodiments, the various techniques described above (e.g., with respect to downlink data) can be adapted for the control channel. It will be appreciated that the current control channel design includes RS in each symbol (e.g., time interval), and thus time division may not be applicable. However, according to some embodiments, the time division described above with respect to data enhancement can also be applied to a control channel that does not include RS in each time interval.

[0109] In some embodiments, the PDCCH may have separate RS (e.g., DMRS) transmissions from different TRPs. For example, the RS associated with the PDCCH may be transmitted from a second TRP in addition to, for example, a first TRP.

[0110] As one method of orthogonalizing the RSs of different TRPs, frequency division can be used. FIG. 11 shows, for example, a combined resource grid showing DMRS transmissions from each TRP on a control channel according to some embodiments. FIG. 12 shows DMRS transmissions from TRP1 according to some embodiments, and FIG. 13 shows DMRS transmissions from TRP2. In other words, FIGS. 12 and 13 show the individual RS transmissions of TRP1 and TRP2, respectively, according to some embodiments.

[0111] As shown in the figure, the DMRS can be transmitted by each TRP in each symbol of the CORESET. The DMRS can be transmitted by each TRP at various frequencies, for example, in periodically spaced REs. In the example shown in the figure, the DMRS can be transmitted by each TRP every 4 REs in each CORESET symbol. Note that other intervals may be used as needed. For example, the RE offset of the DMRS of TRP2 is 3, and the RE offset of the DMRS of TRP1 is 1. In other words, the DMRS of each TRP can occur every 4 REs, TRP1 is in the second RE (e.g., offset by 1 only), and TRP2 is in the fourth RE (e.g., offset by 3).

[0112] As another method of orthogonalizing the RSs of different TRPs, code division may be used. In other words, different TRPs can transmit RSs at the same frequency at the same time, but orthogonal codes can be used for transmission. For example, in a symbol, for each resource block (RB), the first RE and the second RE can be used for the DMRS. Other patterns may be used as needed.

[0113] Figures 14 and 15 show the code division multiplexing (CDM) of RS for the downlink control channel according to some embodiments. As shown in Figure 14, TRP1 can transmit RS using pattern (1-1), and as shown in Figure 15, TRP2 can use pattern (1-1). Based on the orthogonality of these patterns, the UE may be able to receive both the RS from TRP1 and the RS from TRP2 and use these RSs to demodulate the control information from TRP1 and TRP2. The TRP may transmit control information in the REs not used for RS transmission.

[0114] Another approach to enhancing the downlink control channel reliability may include configuring different transmission configuration indication (TCI) states for different TRPs. In some embodiments, the MAC CE may be used to configure two TCIs for the CORESET PDCCH. For example, the first TRP may transmit to the UE a MAC CE indicating the first TCI for the first TRP and the second TCI for the second TRP.

[0115] The TCI state may indicate the quasi-collocation (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 RSs (e.g., QCLed with the control and / or data channels according to the TCI) to decode the DL transmission from TRP501. TRP501 may use upper layer signaling (e.g., radio resource control (RRC)) to configure any number of TCI states and may use lower layer signaling (e.g., downlink control information (DCI)) (e.g., later) to select the TCI state to be used.

[0116] In some embodiments, multiple TCI code points may be defined and configured by RRC. The TCI code points may include one TCI state for each of two TCI states, e.g., two TRPs. Thus, in response to an indication of a TCI code point having two TCI states (e.g., in DCI or MAC CE), the UE may use a first TCI state for a first TRP and a second TCI state for a second TRP. It will be appreciated that a TCI code point having one TCI state may be used for single TRP operation and / or single DCI operation. Further, according to some embodiments, a TCI code point having three or more TCI states may be used.

[0117] In some embodiments, the MAC CE may indicate two TCI states for the same CORESET. FIG. 16 shows a MAC CE having an indication of a second TCI state (e.g., TCI state ID2 is added). Thus, in response to receiving a MAC CE having two TCI state IDs, the UE may use a first TCI state for a first TRP and a second TCI state for a second TRP. A MAC CE having a single TCI state ID may be used for single TRP operation and / or single DCI operation.

[0118] Another approach to enhancing downlink control channel reliability may include the use of a new quasi-collocation (QCL) type to indicate that two RSs are QCL with respect to Doppler shift or frequency offset. In a specification document (e.g., 3GPP® Release 15), the following four QCL types may be predefined (see, e.g., 5.1.5 of 38.214).

[0119] "QCL-TypeA": {Doppler shift, Doppler spread, average delay, delay spread}

[0120] "QCL-TypeB": {Doppler shift, Doppler spread}

[0121] "QCL-TypeC": {Doppler shift, average delay}

[0122] "QCL-TypeD": {Spatial Rx parameter}

[0123] Thus, in some embodiments, a fifth QCL type (e.g., type E) may be defined. The fifth type may be described, for example, as follows.

[0124] "QCL-TypeE": {Doppler shift}

[0125] In other words, the new type may be, for example, a stand-alone QCL based only on the Doppler shift. This may be in contrast to the current QCL types that may bundle the Doppler shift with other characteristics (e.g., Doppler spread in the case of QCL type B).

[0126] In some embodiments, the control information data transmitted from the TRP (e.g., associated with the RS) may be the same. For example, a first TRP may transmit first control information to the UE in a slot / CORESET. In the same slot / CORESET (e.g., using any of the orthogonalization techniques described 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 the 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 / second control information. Uplink RS Enhancement

[0127] The sounding reference signal (SRS) and / or other uplink RS may be enhanced to support uplink transmission 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 the movement of the UE.

[0128] In some embodiments, the MAC CE can be used to update the configuration for periodic SRS (P-SRS). For example, the MAC CE can be used to indicate which path loss RS can be used by the UE to estimate the path loss between the UE and the TRP for the determination of the transmission power of P-SRS based on open-loop power control. The same MAC CE or a different MAC CE can 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 can indicate multiple spatial relationships (e.g., directly indicating multiple TCI states or similar to the description of one MAC CE indicating TCI symbol points having multiple TCIs). For example, the MAC CE can directly indicate multiple spatial relationships or can indicate the spatial relationship symbol points that define multiple spatial relationships. Thus, the UE can transmit RS using multiple spatial relationships. The multiple spatial relationships can correspond to multiple TRPs (e.g., the first spatial relationship for the first TRP, etc.). The network can use the RS received at each TRP to estimate the channel between the UE and each TRP and / or demodulate the uplink transmission from the UE to each TRP. Using the MAC CE to update the configuration of the uplink RS (including, for example, the spatial relationship) can be faster than using the RRC to update the configuration. The DCI can be used to update the configuration of the uplink RS according to some embodiments.

[0129] 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 uplink RS only by the frequency offset of the spatial relation. Thus, the UE may "pre-correct" the uplink RS for the Doppler shift associated with the movement of the UE. 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 can 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 movement of the UE) and 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 for a spatial relation (e.g., based on measurements of downlink RS or other knowledge of the movement of the UE). In some embodiments, the frequency offset for one spatial relation may be determined based on the frequency offset for another spatial relation. For example, if the frequency offset for a TRP in front of the UE (e.g., in the direction of travel of the UE) is known, the frequency offset for another TRP behind the UE may be determined by inverting the sign of the frequency offset (e.g., multiplying by -1).

[0130] In some embodiments, the UE may transmit SRS or other uplink RS based on the absolute channel number (e.g., the frequency without offset as determined by the lower layer, e.g., layer 1), regardless of the estimated frequency offset. In other words, the uplink RS may be transmitted without frequency correction (by the UE) for UE movement. On the receiver side, the TRP may estimate the UE frequency offset due to UE movement from the SRS. From the UE frequency offset estimate, the TRP may correct for UE movement. For example, according to some embodiments, the TRP may apply a frequency offset (e.g., opposite) during transmission to the UE such that, for example, the received signal at the UE side is not affected by UE movement.

[0131] In some embodiments, the tracking reference signal (TRS) may be configured as a spatial relationship to the semi-persistent (SP) SRS, aperiodic (AP) SRS, and / or P-SRS. For example, the UE may be able to estimate the frequency offset from the configured TRS, and the frequency offset may be used to determine the UL transmission frequency of the P / SP / AP-SRS for which the TRS is configured as a spatial relationship. New communication modes for high-speed moving UEs

[0132] The new operation mode may be configured for use by the network and the UE when the UE is moving at high speed. For example, such a mode may be called, among other possibilities, the high-speed train (HST) mode. Such a mode may be useful for single DCI, multi-TRP operation. For example, the single DCI multi-TRP operation of Release 16 may be enhanced to support high-speed movement such as a UE on an HST. In other words, a special mode of single DCI multi-TRP operation may be configured.

[0133] In some embodiments, in the new mode, the RRC-configured TCI code points may include two TCI states. For example, as described above, one TCI state may be used for communicating with one TRP, and another TCI state may be used for another TRP. For example, the UE may transmit uplink RS according to the TCI state, and / or the network may transmit downlink RS to the UE according to the TCI state.

[0134] In some embodiments, QCL and / or spatial relationships may be configured for multiple TRPs in the new mode.

[0135] In some embodiments, in the new mode, various ones of the adaptations described above may be applied by the UE and / or the network / TRP.

[0136] In some embodiments, in the new mode, one of the TRPs may provide DCI for uplink and downlink communication with both TRPs.

[0137] When one or more of the following conditions are true, (e.g., by the UE and / or the network / TRP) it is possible to enter the new mode.

[0138] The first condition may include that repetitionScheme-r16 is not configured by RRC. In other words, the first condition may include that none of the following single DCI multi-TRP modes according to some embodiments, namely, (1) FDMSchemeA, (2) FDMSchemeB, and / or (3) TDMSchemeA, are configured.

[0139] The second condition may include at least one of the following: repetitionNumber-r16 is not configured in any entry in PDSCH-TimeDomainResourceAllocation, or repetitionNumber-r16 is not indicated in the DCI field time domain resource allocation. In other words, a single DCI Multi-TRP scheme 4 or an inter-slot TDM scheme cannot be configured.

[0140] If both of the above conditions are true and one or three CDM groups are indicated in the DCI antenna port field, the network and / or the UE may consider the conditions as an implicit indication to operate according to the new operating mode. For example, the third condition may include that one or three CDM groups are configured.

[0141] Alternatively, the network may explicitly configure the new operating mode (e.g., by means of RRC and / or MAC CE).

[0142] Based on the implicit or explicit indication, the UE and the network may operate according to the new mode, for example, until the conditions change or an explicit indication for changing the mode is sent.

[0143] In some embodiments, a further condition for entering the new mode may be that the UE is moving at a high speed (e.g., above a threshold speed). Thus, the UE may not enter the new mode if it is not moving fast enough. The movement / speed may be determined based on various means including, but not limited to, radio measurements, GNSS, movement sensors, etc.

[0144] In some embodiments, the downlink RS transmitted by one or more TRPs may be corrected for Doppler shift using a frequency offset in a manner similar to the method described above for the uplink RS.

[0145] In some embodiments, the UE may determine frequency offset information based on downlink RSs from one or more TRPs. The UE may apply the frequency offset information to the transmission of uplink RSs to one or more TRPs.

[0146] In some embodiments, the network may determine frequency offset information based on uplink RSs from the UE to one or more TRPs. The network may apply the frequency offset information to the transmission of downlink RSs from one or more TRPs to the UE.

[0147] In a first set of embodiments, the base station may include a radio and a processor operably connected to the radio 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) in a first symbol, transmit a second RS from a second TRP to the UE in the first symbol, transmit first control information from the first TRP to the UE in the first symbol, the first control information being configured to be demodulated using the first RS, and transmit second control information from the second TRP to the UE in the first symbol, the second control information being configured to be demodulated using the second RS.

[0148] In some embodiments, the first RS and the second RS may be transmitted in a plurality of resource elements in the first symbol, and the resource elements in which the second RS is transmitted are offset from the resource elements in which the first RS is transmitted.

[0149] In some embodiments, the first RS and the second RS may be transmitted in a plurality of resource elements in the first symbol, the resource elements in which the second RS is transmitted are the same as the resource elements in which the first RS is transmitted, and the first RS and the second RS are orthogonalized using code division multiplexing.

[0150] In some embodiments, the processor may be further configured to cause the base station to transmit control information including transmission configuration indication (TCI) code points from a first TRP to a UE, the TCI code points indicating a first TCI state and a second TCI state, a first RS being transmitted according to the first TCI state, and a second RS being transmitted according to the second TCI state.

[0151] In some embodiments, the processor may be further configured to cause the base station to transmit control information including a media access control (MAC) control element (CE) from a first TRP to a UE, the MAC CE indicating a first transmission configuration indication (TCI) state and a second TCI state for a first control resource set (CORESET), a first RS being transmitted according to the first TCI state, a second RS being transmitted according to the second TCI state, and a first symbol being associated with the first CORESET.

[0152] In some embodiments, the processor may be further configured to cause the base station to transmit control information including an indication that a first RS is quasi - co - located with a third RS with respect to at least one of a Doppler shift or a frequency offset from a first TRP to a UE.

[0153] In some embodiments, the control information may further include an indication that a second RS is quasi - co - located with a fourth RS with respect to at least one of a Doppler shift or a frequency offset.

[0154] In some embodiments, the processor may be further configured to cause the base station to transmit from a first TRP to a UE control information comprising a media access control (MAC) control element (CE), the MAC CE indicating to the UE to update the configuration of periodic sounding RS, and at a first TRP and a second TRP, cause the UE to receive periodic sounding RS according to the configuration.

[0155] In a second set of embodiments, the apparatus causes a base station of a cellular network to establish communication with a UE via a first transmission and reception point (TRP), and causes the first TRP to transmit to the UE a medium access control (MAC) control element (CE), the MAC CE including an indication for using a plurality of spatial relationships for transmission of uplink periodic reference signals (RSs), causes the first TRP to receive from the UE an uplink RS according to a first spatial relationship among the plurality of spatial relationships, and causes the second TRP to receive from the UE an uplink RS according to a second spatial relationship among the plurality of spatial relationships, and may include a processor configured as such.

[0156] In some embodiments, the uplink periodic RS may be a sounding RS.

[0157] In some embodiments, the MAC CE further includes an indication of a path loss RS for uplink power control of the uplink periodic RS.

[0158] In some embodiments, the first spatial relationship may include a first frequency offset.

[0159] In some embodiments, the second spatial relationship may include a second frequency offset different from the first frequency offset.

[0160] In some embodiments, the processor may be further configured to cause the base station to determine that the UE is moving at high speed between the first TRP and the second TRP, and the transmission of the MAC CE is responsive to the determination.

[0161] In some embodiments, the processor may be further configured to cause the base station to compensate for the Doppler shift of the uplink RS, and the Doppler shift of the uplink RS received via the first TRP is different from the Doppler shift of the uplink RS received via the second TRP.

[0162] In a third set of embodiments, the method comprises establishing communication with a user equipment device (UE) in a cellular network, determining that the UE is moving at high speed between a first transmission and reception point (TRP) and a second TRP, and in response to the determination, causing the first TRP to transmit to the UE a first demodulation reference signal (DMRS) that is UE-specific on a first time / frequency resource within a first slot, causing the second TRP to transmit to the UE a second DMRS that is UE-specific on a second time / frequency resource within the first slot and different from the first time / frequency resource, causing the first TRP to transmit to the UE first data demodulated using the first DMRS, and causing the second TRP to transmit to the UE second data demodulated using the second DMRS.

[0163] In some embodiments, the first time / frequency resource is a time / frequency resource associated with a DMRS transmitted to a UE not determined to be moving at high speed.

[0164] In some embodiments, the method may further comprise causing at least one of the first TRP or the second TRP to transmit to the UE an indication of the second time / frequency resource.

[0165] In some embodiments, the indication may include an indication of an offset of the second time / frequency resource relative to the first time / frequency resource.

[0166] In some embodiments, the method may further comprise splitting a time / frequency resource associated with a DMRS transmitted to a UE not determined to be moving at high speed, wherein the second time / frequency resource and the first time / frequency resource are separate subsets of the time / frequency resource associated with a DMRS transmitted to a UE not determined to be moving at high speed.

[0167] 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 may be associated with a second CDM group.

[0168] In a fourth set of embodiments, a user equipment device (UE) may include a radio and a processor operably connected to the radio and configured to cause the UE to determine that the UE is moving at high speed between a first transmit receive point (TRP) and a second TRP, that a repetition pattern is not configured, and that one or three code division multiplexing groups are indicated in an antenna port field, and in response to the determination, cause the UE to enter a first operating mode associated with high speed movement.

[0169] In some embodiments, the first operating mode may include single downlink control information (DCI) and a multi-TRP mode.

[0170] In some embodiments, in accordance with the first mode, a transmission configuration indication (TCI) code point may be configured, and the TCI code point indicates a first TCI state and a second TCI state.

[0171] In some embodiments, the processor may be further configured to cause the UE to receive a first reference signal (RS) from a first TRP according to the first TCI state and a second RS from a second TRP according to the second TCI state.

[0172] In some embodiments, the first RS may be a channel state information RS, the first RS is received in a first symbol, and the processor may be further configured to cause the UE to receive control information from the first TRP during the first symbol and demodulate the control information using the first RS.

[0173] In some embodiments, the processor may be further configured to cause the UE to transmit a first reference signal (RS) to a first transmission and reception point (TRP) according to a first TCI state and a second RS to a second TRP according to a second TCI state.

[0174] In some embodiments, the processor may be further configured to cause the UE to perform uplink transmissions to the first TRP and the second TRP according to a first mode.

[0175] In a fifth set of embodiments, the 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 that includes an indication for using a plurality of spatial relationships for transmission of uplink periodic reference signals (RSs), cause the UE to transmit an uplink RS to the first TRP according to a first spatial relationship among the plurality of spatial relationships, and cause the UE to transmit an uplink RS to a second TRP according to a second spatial relationship among the plurality of spatial relationships.

[0176] In some embodiments, the processor may be a baseband processor.

[0177] In some embodiments, the uplink periodic RS may be a sounding RS.

[0178] In some embodiments, the MAC CE includes an indication of a path loss RS for use in uplink power control of the uplink periodic RS.

[0179] In some embodiments, transmitting the uplink RS to the first TRP may include performing uplink power control based on a path loss RS from the first TRP.

[0180] In some embodiments, transmitting the uplink RS to the second TRP may include performing uplink power control based on a path loss RS from the second TRP.

[0181] In some embodiments, the first spatial relationship may include a first frequency offset.

[0182] In some embodiments, the second spatial relationship may include a second frequency offset different from the first frequency offset.

[0183] In some embodiments, transmitting the uplink RS according to the first spatial relationship may correct the uplink RS with respect to the movement of the UE.

[0184] In some embodiments, transmitting the uplink RS may be based on a channel number without a frequency offset.

[0185] In a sixth set of embodiments, the method includes, in a user equipment device (UE), establishing communication with a cellular network, receiving a first downlink reference signal (RS) from a first transmit receive point (TRP) of the cellular network, receiving a second downlink RS from a second TRP of the cellular network, the second downlink RS being orthogonal to the first downlink RS, and communicating with the first TRP and the second TRP simultaneously, the communicating including 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.

[0186] In some embodiments, the first downlink RS and the second downlink RS may be time division multiplexed, and the first downlink signal and the second downlink signal may be data communication.

[0187] In some embodiments, the first downlink RS and the second downlink RS may be received by different antenna ports.

[0188] In some embodiments, the first downlink RS and the second downlink RS may be code-division multiplexed.

[0189] In some embodiments, the first downlink RS and the second downlink RS may be frequency-division multiplexed.

[0190] 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 the first uplink RS transmitted to the first TRP.

[0191] In various embodiments, various combinations of the above adaptations may be performed together. For example, the network may transmit 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.

[0192] Yet another exemplary embodiment can include a method performed by a wireless device that includes performing any or all parts of the preceding examples.

[0193] Other exemplary embodiments can include a wireless device, which can include a device comprising an antenna, a radio coupled to the antenna, and a processing element operably coupled to the radio, the device being configured to implement any or all parts of the foregoing examples.

[0194] Yet another exemplary embodiment can include an apparatus comprising a processing element configured to cause a wireless device to perform any or all parts of any of the preceding examples.

[0195] A further exemplary set of embodiments can include a non-transitory computer-accessible memory medium that, when executed on a device, causes the device to perform any or all parts of any of the foregoing examples, including program instructions.

[0196] A further exemplary set of embodiments can include a computer program that includes instructions to perform any or all parts of any of the foregoing examples.

[0197] Another exemplary set of embodiments can include an apparatus that includes means for performing any or all of any of the elements of the foregoing examples.

[0198] Any of the methods described herein for operating a user equipment (UE) can be the basis for a corresponding method for operating a base station by interpreting each message / signal X received by the UE in the DL as a message / signal X transmitted by the 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.

[0199] In addition to the above exemplary embodiments, further embodiments of the present disclosure can be implemented in any of a variety of forms. For example, some embodiments can be implemented as a method performed by a computer, 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.

[0200] In some embodiments, the non-transitory computer-readable memory medium may be configured to store program instructions and / or data, which, when executed by a computer system, cause the computer system to execute the method, for example, any of the embodiments of the methods described herein, or any combination of the embodiments of the methods described herein, or any subset of the embodiments of the methods described herein, or any combination of such subsets.

[0201] In some embodiments, a device (e.g., UE106 or 107) may be configured to include a processor (or a set of processors) and a memory medium. Here, the memory medium stores program instructions, and the processor is configured to read and execute the program instructions from the memory medium. The program instructions are executable to execute any of the various method embodiments described herein (or any combination of the method embodiments described herein, or any arbitrary subset of any of the method embodiments described herein, or any combination of such subsets). The device may be implemented in any of various forms.

[0202] It is well understood that the use of personal information should comply with privacy policies and practices generally recognized as meeting or exceeding industry or government requirements for maintaining user privacy. In particular, personal information data should be managed and handled to minimize the risk of unintended or unauthorized access or use, and the nature of authorized use should be clearly shown to the user.

[0203] Although the above embodiments have been described in considerable detail, many variations and modifications will become apparent to those skilled in the art if the above disclosure is fully understood. The following claims are intended to be construed as encompassing all such variations and modifications.

Claims

1. For a first control resource set (CORESET), transmitting a medium access control (MAC) control element (CE) indicating a first transmission configuration indication (TCI) state and a second TCI state from a first transmission and reception point (TRP) to a user equipment device (UE); Transmitting a first reference signal (RS) that is a UE-specific reference signal in a coded region in a first symbol from the first TRP to the UE according to the first TCI state; Transmitting a second RS that is a UE-specific RS in a coded region in the first symbol from a second TRP to the UE according to the second TCI state; Transmitting first control information from the first TRP to the UE in a first physical downlink control channel (PDCCH) transmission in the first symbol of the CORESET according to the first TCI state; Transmitting second control information from the second TRP to the UE in a second PDCCH transmission in the first symbol of the CORESET according to the second TCI state; Including; The method, wherein the second control information is a copy of the first control information.

2. The first control information is configured to be demodulated using the first RS, The method according to claim 1, wherein the second control information is configured to be demodulated using the second RS.

3. The method according to claim 1, wherein the first control information includes a first physical downlink control channel (PDCCH) message.

4. The MAC CE includes A serving cell identifier and An identifier of the first CORESET, the method according to claim 1.

5. The MAC CE includes An identifier of the first TCI state and An identifier of the second TCI state, the method according to claim 1.

6. An apparatus comprising a processor configured to cause a base station to execute the method according to any one of claims 1 to 5.

7. A computer-readable memory medium comprising program instructions configured to cause a base station to execute the method according to any one of claims 1 to 5.

8. A base station, comprising A radio and A processor operably coupled to the radio and configured to cause the base station to execute the method according to any one of claims 1 to 5. The base station comprising.

9. A method executed by a processor of a user equipment device (UE), comprising: Receiving, from a first transmission and reception point (TRP), a media access control (MAC) control element (CE) indicating a first transmission configuration indication (TCI) state and a second TCI state for a first control resource set (CORESET); Receiving, from the first TRP, a first reference signal (RS) that is a UE-specific RS in a coded region within a first symbol according to the first TCI state; Receiving, from a second TRP, a second RS that is a UE-specific RS in a coded region within the first symbol according to the second TCI state; Receiving, from the first TRP, first control information in a first physical downlink control channel (PDCCH) transmission according to the first TCI state within the first symbol of the CORESET; Receiving, from the second TRP, second control information in a second PDCCH transmission according to the second TCI state within the first symbol of the CORESET; Including: The method, wherein the second control information is a copy of the first control information. **Claim 10** The first control information is configured to be demodulated using the first RS; The second control information is configured to be demodulated using the second RS. The method according to claim 9. **Claim 11** The method according to claim 9, wherein the first control information includes a first physical downlink control channel (PDCCH) message. **Claim 12** The MAC CE includes: A serving cell identifier; and An identifier of the first CORESET. **Claim 13** The MAC CE includes: An identifier of the first TCI state; and An identifier of the second TCI state. **Claim 14** An apparatus comprising a processor configured to cause a user equipment to execute the method according to any one of claims 9 to 13. **Claim 15** A computer-readable memory medium comprising program instructions configured to cause a user equipment to execute the method according to any one of claims 9 to 13. **Claim 16** A user equipment, comprising: A radio; and A processor operably coupled to the radio and configured to cause the user equipment to execute the method according to any one of claims 9 to 13. The user equipment.

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