Downlink transmission configuration indication based on sounding reference signal

Abstract

To reduce beam reporting delays, a base station may include a sounding reference signal (SRS) indication to a wireless communication device (UE) as part of transmission configuration information (TCI) transmitted to the UE, thereby allowing the UE to receive the corresponding downlink signal using the same beam (or utilizing the same beam) as the beam used by the UE to transmit (or used by the UE to transmit) the SRS indicated in the TCI. The SRS may be one of multiple SRSs previously transmitted by the UE. The UE may transmit multiple SRSs periodically and / or according to semi-persistent scheduling, or the UE may transmit the SRS non-periodically. Therefore, the UE does not need to report beam quality, and the base station may instead perform the necessary beam measurements. Various parameters and conditions may be defined for the UE to support SRS-based TCI.

Description

Technical Field

[0001] The present application relates to wireless communications, and more particularly to providing a sounding reference signal (SRS) based downlink transmission configuration indication (TCI) during wireless communications, such as during 3GPP New Radio (NR) communications.

[0002] Related technical description

[0003] The use of wireless communication systems is growing rapidly. In recent years, wireless devices such as smart phones and tablets have become increasingly sophisticated. In addition to supporting phone calls, many mobile devices (i.e., user equipment devices or UEs) now also provide access to the Internet, email, text messaging, and navigation using a global positioning system (GPS), and are capable of operating complex and sophisticated applications that utilize these functions. In addition, there are many different wireless communication technologies and wireless communication standards. Some examples of wireless communication standards include GSM, UMTS (WCDMA, TDS-CDMA), LTE, LTEAdvanced (LTE-A), HSPA, 3GPP2 CDMA2000 (e.g., 1xRTT, 1xEV-DO, HRPD, eHRPD), IEEE 802.11 (WLAN or Wi-Fi), IEEE 802.16 (WiMAX), BLUETOOTH TM etc. The proposed next telecommunication standard beyond the current International Mobile Telecommunications Advanced (IMT-Advanced) standard is known as the 5th generation mobile network or 5th generation wireless system, referred to as 3GPP NR (also known as 5G New Radio (5G-NR), also referred to as NR for short). NR provides higher capacity for a higher density of mobile broadband users while supporting device-to-device, ultra-reliable and massive machine communications, as well as lower latency and lower battery consumption than the current LTE standard.

[0004] The introduction of an ever-increasing number of features and functions in wireless communication devices also requires continuous improvements in wireless communications and improvements in wireless communication devices. Of particular importance is ensuring the accuracy of signals transmitted and received by user equipment (UE) devices (e.g., by wireless devices such as cellular phones, base stations, and relay stations used in wireless cellular communications). In many cases, modern wireless communication networks use MIMO (Multiple Input Multiple Output) technology to achieve high data rates. One MIMO technology is beamforming, which allows directional illumination of a specific area so that transmissions to users at the far edge of cellular coverage can be improved. Beamforming is an important component of many wireless communication standards such as WLAN and WiMAX. TM Beamforming is one of many features of LTE, LTE and NR. Beamforming is especially important for the time division duplex (TDD) mode in LTE and NR.

[0005] Wireless communication standards such as 3GPP LTE and 3GPP NR also provide for additional signaling intended to improve communications. One example is the Sounding Reference Signal (SRS), which is a reference signal transmitted by the UE in the uplink direction and is used by the base station to estimate the uplink channel quality over a wider bandwidth. The base station can use this information for uplink frequency selective scheduling and can also use the SRS for uplink timing estimation as part of the timing alignment process, especially when there are no PUSCH / PUCCH transmissions in the uplink for a long period of time, and therefore relies on the SRS for uplink timing estimation. The SRS does not need to be transmitted in the same physical resource block as the PUSCH is transmitted, because the SRS can extend over a larger frequency range.

[0006] Another useful feature in wireless communications (e.g., in beamforming) is that it is possible to utilize a reference signal associated with one channel to determine the communication conditions associated with another channel. Therefore, reference signals associated with different corresponding channels can be considered to have a quasi-co-location (QCL) relationship determined based on the corresponding antennas associated with those reference signals. Thus, if the properties of the channel that transmits the symbols on one antenna port can be inferred from the channel that transmits the symbols on the other antenna port, the two antenna ports are considered to be quasi-co-located (QCL). For example, two reference signals transmitted by the same antenna array and applying the same spatial filter will experience similar channel conditions and have similar channel properties. Since these reference signals have similar channel properties, the UE can detect one of the reference signals and can apply the channel properties of the reference signal to detect the other reference signal. Therefore, the two reference signals are considered to be QCL.

[0007] An indication of the QCL relationship may be provided to the UE in the downlink control information (DCI) as part of the transmission configuration indication (TCI). The TCI may include configurations such as the QCL relationship between a downlink reference signal (DL-RS) and a PDSCH demodulation reference signal (DMRS) port in a channel state information RS (CSI-RS) set. Each TCI state can contain parameters for configuring the QCL relationship between one or two downlink reference signals and a DMRS port of a PDSCH, a DMRS port of a PDCCH, or a CSI-RS port of a CSI-RS resource. In an effort to improve reporting delays, further improvements to the transmission of TCI are expected.

[0008] Other corresponding problems related to the prior art will become apparent to those skilled in the art after comparing such prior art with the disclosed embodiments described herein. Summary of the invention

[0009] In particular, embodiments of a method for implementing transmission of a downlink transmission configuration indication (TCI) based on a sounding reference signal (SRS), for example, during 3GPP New Radio (NR) communications are presented herein. Embodiments of a wireless communication system are further presented herein, the wireless communication system comprising a user equipment (UE) device and / or base stations communicating with each other within the wireless communication system.

[0010] To reduce beam reporting delay, SRS-based downlink beam indication or SRS-based downlink TCI may be implemented. The UE may transmit multiple SRSs in different beams, and the base station may indicate one of the SRSs to the UE in the TCI. Based on the SRS indication, the UE may receive downlink signals using the same beam as the UE used to transmit the SRS. Therefore, the UE does not need to report beam quality, as the base station may instead perform the necessary beam measurements.

[0011] According to the above, the UE may transmit multiple SRSs continuously to the base station, which includes the UE transmitting the first SRS using the first beam. The UE may receive an indication of the first SRS among the multiple SRSs from the base station in the TCI at least in response to the base station receiving the first SRS. The UE may then receive a downlink signal corresponding to the first SRS from the base station using the first beam in response to at least receiving the indication of the first SRS. The first SRS may be transmitted within a specified number of time slots before the TCI is received from the base station, or within a specified number of time slots before the downlink signal is received from the base station. In this case, the specified number of time slots may represent spatial relationship information corresponding to the indication of the SRS received by the UE in the TCI, and the UE may use (or follow) the information to determine which beam to use to receive the downlink signal. The TCI may be received in a physical control channel corresponding to the first SRS, and the downlink signal may be received in a physical data channel corresponding to the first SRS. The specified number may be a predefined number, a number configured by higher layer signaling, or may be reported by device capability signaling.

[0012] In some embodiments, when the multiple SRS are periodic or semi-persistent SRS, each of the multiple SRS may be transmitted using the same beam. In the case where the multiple SRS are non-periodic, that is, they are not periodic or semi-persistent SRS, the first SRS may be the SRS most recently transmitted before the corresponding downlink signal is received. In some embodiments, the first beam may be identified based on the spatial relationship information for the latest indication of the SRS.

[0013] In some embodiments, a TCI state with SRS as the source reference signal may not be configured for CORESET 0 or any CORESET in the CORESET. The UE may monitor CORESET 0 associated with a specific synchronization signal block until a new TCI is received or until the physical random access procedure commanded by the physical control channel does not trigger the random access channel procedure. The SRS may be an SRS for beam management, an SRS for codebook-based transmission, an SRS for non-codebook-based transmission, and / or an SRS for antenna switching. The downlink signal may be a physical data channel, a channel state information reference signal (CSI-RS) with repeated on, a CSI-RS with repeated off, a CSI-RS with tracking reference signal (TRS) information configured, a CSI-RS without repetition and without TRS information configured, or a CORESET. The first SRS may indicate quasi-co-location parameters, which may include spatial reception parameters, delay offset, Doppler shift, delay spread, and / or Doppler spread. The first SRS may be transmitted in the same serving cell as the downlink signal or in a serving cell different from the downlink signal. The serving cell index for the first SRS and / or the bandwidth portion index for the first SRS may be configured by higher layer signaling (e.g., via radio resource control (RRC) signaling). In some embodiments, the base station may assume that downlink signals can be received simultaneously when corresponding source SRSs are configured in different resource sets having the same purpose, or when corresponding source SRSs are configured in different panel identifiers having the same purpose.

[0014] In some embodiments, the base station may receive a first SRS transmitted by the device using a first beam from the device, and may transmit an indication of the first SRS in the TCI in response to at least receiving the first SRS, so that the device receives a downlink signal using the first beam. The base station may then transmit a downlink signal to the device, and the device may receive the downlink signal using the first beam.

[0015] It should be noted that the techniques described herein may be implemented in and / or used with a number of different types of devices, including but not limited to base stations, access points, cellular telephones, portable media players, tablet computers, wearable devices, and various other computing devices.

[0016] This disclosure is intended to provide a brief overview of some of the topics described in this document. Therefore, it should be understood that the above features are only examples and should not be construed as narrowing the scope or essence of the topics described herein in any way. Other features, aspects and advantages of the topics described herein will become apparent through the following detailed description, drawings and claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 An exemplary (and simplified) wireless communication system according to some embodiments is shown;

[0018] Figure 2 illustrates an exemplary base station in communication with an exemplary wireless user equipment (UE) device in accordance with some embodiments;

[0019] Figure 3 is an exemplary block diagram of a UE according to some embodiments;

[0020] Figure 4 is an exemplary block diagram of a base station according to some embodiments;

[0021] Figure 5 shows an exemplary simplified block diagram illustrating cellular communication circuitry according to some embodiments;

[0022] Figure 6 A timing diagram illustrating SRS signaling, PDCCH transmission, PDSCH transmission and corresponding beam patterns is shown;

[0023] Figure 7 shows a timing diagram illustrating SSB and SS / CORESET0 transmission and TCI indication;

[0024] Figure 8 A timing diagram showing SRS signaling, PDCCH transmission, and PDSCH transmission when beams are used based on the timing of SRS and downlink beam reception of corresponding PDSCH according to an illustration of some embodiments;

[0025] Fig. 9 A timing diagram showing SRS signaling, PDCCH transmission, and PDSCH transmission when beams are used based on the timing of SRS and downlink beam reception of corresponding PDCCHs according to an illustration of some embodiments;

[0026] Fig.10 A timing diagram showing SRS signaling, PDCCH transmission, and PDSCH transmission when the same beam is used for all SRS transmissions and downlink channel receptions according to an illustration of some embodiments;

[0027] Fig.11 A timing diagram showing SSB and SS / CORESET0 transmissions and TCI indications when a UE monitors SS / CORESET 0 according to some embodiments;

[0028] Fig.12 A timing diagram showing SRS signaling, PDCCH transmission, and PDSCH transmission when source SRS is configured in different resource sets having the same purpose according to an illustration of some embodiments; and

[0029] Fig.13 A timing diagram of SRS signaling, PDCCH transmission, and PDSCH transmission when source SRS are configured in different panel IDs having the same purpose is shown according to an illustration of some embodiments.

[0030] Although the features described herein are susceptible to various modifications and alternative forms, specific embodiments thereof are shown by way of example in the drawings and described in detail herein. However, it should be understood that the drawings and detailed description thereof are not intended to limit this document to the specific forms disclosed, but on the contrary, their purpose is to cover all modifications, equivalents and alternatives that fall within the spirit and scope of the subject matter as defined by the appended claims. DETAILED DESCRIPTION

[0031] Acronyms

[0032] Various acronyms are used throughout this patent application. The definitions of the most prominent acronyms used that may appear throughout this patent application are as follows:

[0033] APR: Application Processor

[0034] BS: Base Station

[0035] BSR: Buffer Size Report

[0036] CMR: Change Mode Request

[0037] CRC: Cyclic Redundancy Check

[0038] CSI: Channel State Information

[0039] DCI: Downlink Control Information

[0040] DL: Downlink (from BS to UE)

[0041] DYN: Dynamic

[0042] FDD: Frequency Division Duplex

[0043] FT: frame type

[0044] GC-PDCCH: Group Common Physical Downlink Control Channel

[0045] GPRS: General Packet Radio Service

[0046] GSM: Global System for Mobile Communications

[0047] GTP: GPRS Tunneling Protocol

[0048] IR: Initialization and refresh status

[0049] LAN: Local Area Network

[0050] LTE: Long Term Evolution

[0051] MAC: Media Access Control

[0052] MAC-CE: MAC control element

[0053] MIB: Master Information Block

[0054] MIMO: Multiple Input Multiple Output

[0055] OSI: Open Systems Interconnection

[0056] PBCH: Physical Broadcast Channel

[0057] PDCCH: Physical Downlink Control Channel

[0058] PDCP: Packet Data Convergence Protocol

[0059] PDN: Packet Data Network

[0060] PDSCH: Physical Downlink Shared Channel

[0061] PDU: Protocol Data Unit

[0062] QCL: Quasi-Co-location

[0063] RACH: Random access process

[0064] RAT: Radio Access Technology

[0065] RF: Radio Frequency

[0066] RMSI: Remaining Minimum System Information

[0067] ROHC: Robust Header Compression

[0068] RRC: Radio Resource Control

[0069] RS: Reference signal (symbol)

[0070] RSI: Root Sequence Indicator

[0071] RTP: Real-time Transport Protocol

[0072] RX: Receive / Receive

[0073] SID: System Identification Number

[0074] SGW: Service Gateway

[0075] SRS: Sounding Reference Signal

[0076] SS: Search Space

[0077] SSB: Synchronous Signal Block

[0078] TBS: Transport Block Size

[0079] TCI: Transmission Configuration Indicator

[0080] TDD: Time Division Duplex

[0081] TRS: Tracking Reference Signal

[0082] TX: Transmit / Transmit

[0083] UE: User Equipment

[0084] UL: Uplink (from UE to BS)

[0085] UMTS: Universal Mobile Telecommunications System

[0086] Wi-Fi: Wireless local area network (WLAN) RAT based on the Institute of Electrical and Electronics Engineers (IEEE) 802.11 standard

[0087] WLAN: Wireless LAN

[0088] the term

[0089] The following is a glossary of terms that will appear in this application:

[0090] Memory medium - any of various types of memory devices or storage devices. The term "memory medium" is intended to include installation media, such as CD-ROM, floppy disk or tape devices; computer system memory or random access memory such as DRAM, DDR RAM, SRAM, EDO RAM, Rambus RAM, etc.; non-volatile memory such as flash memory, magnetic media, for example, hard disk drive or optical storage device; registers, or other similar types of memory elements, etc. The memory medium may also include other types of memory or a combination thereof. In addition, the memory medium may be located in a first computer system executing a program, or may be located in a different second computer system connected to the first computer system via a network such as the Internet. In the latter example, the second computer system may provide program instructions to the first computer system for execution. The term "memory medium" may include two or more memory media that may reside in different locations in different computer systems connected, for example, via a network. The memory medium may store program instructions (e.g., in the form of a computer program) that may be executed by one or more processors.

[0091] Carrier Medium—storage media as described above, and physical transmission media such as a bus, network, and / or other physical transmission media that transport signals such as electrical, electromagnetic or digital signals.

[0092] Programmable hardware element - includes various hardware devices that include multiple programmable function blocks connected via programmable interconnects. Examples include FPGA (field programmable gate array), PLD (programmable logic device), FPOA (field programmable object array), and CPLD (complex PLD). Programmable function blocks can vary from fine-grained (combinational logic unit or lookup table) to coarse-grained (arithmetic logic unit or processor core). Programmable hardware elements may also be referred to as "configurable logic units".

[0093] Computer system (or computer)—any of various types of computing or processing systems, including a personal computer system (PC), a mainframe computer system, a workstation, a network appliance, an Internet appliance, a personal digital assistant (PDA), a television system, a grid computing system, or other devices or combinations of devices. In general, the term "computer system" may be broadly defined as any device (or combination of devices) that includes at least one processor that executes instructions from a memory medium.

[0094] User Equipment (UE) (or "UE device") - any of various types of computer system devices that perform wireless communications. Also referred to as wireless communication devices, many of which may be mobile and / or portable. Examples of UE devices include mobile phones or smart phones (e.g., iPhone TM , based on Android TM phones) and tablets such as iPads TM 、Samsung Galaxy TM etc., gaming devices (such as Sony PlayStation TM , Microsoft XBox TM etc.), portable gaming devices (e.g., Nintendo DS TM , PlayStation Portable TM 、Gameboy Advance TM , iPod TM ), laptops, wearable devices (e.g., Apple Watch TM , Google Glass TM), PDAs, portable Internet devices, music players, data storage devices or other handheld devices, etc. Various other types of devices may include Wi-Fi communication capabilities or both cellular and Wi-Fi communication capabilities and / or other wireless communication capabilities (e.g., via short-range radio access technologies (SRAT) such as BLUETOOTH TM In general, the term "UE" or "UE device" can be broadly defined to cover any electronic device, computing device and / or telecommunication device (or combination of devices) capable of wireless communication and may also be portable / mobile.

[0095] Wireless device (or wireless communication device) - any of various types of computer system devices that perform wireless communication using WLAN communication, SRAT communication, Wi-Fi communication, etc. As used herein, the term "wireless device" may refer to a UE device as defined above or a fixed device such as a fixed wireless client or a wireless base station. For example, a wireless device may be a wireless station of any type of 802.11 system, such as an access point (AP) or a client station (UE), or a wireless station of any type of cellular communication system that communicates according to a cellular radio access technology (e.g., LTE, CDMA, GSM), such as a base station or a cellular phone.

[0096] Communication device - any of various types of computer systems or devices that perform communication, where the communication may be wired or wireless. A communication device may be portable (or mobile), or may be stationary or fixed at a location. A wireless device is an example of a communication device. A UE is another example of a communication device.

[0097] Base Station (BS)—The term "base station" has the full breadth of its ordinary meaning and includes at least a wireless communication station installed at a fixed location and used to communicate as part of a wireless telephone system or radio system.

[0098] Processor—refers to various elements (e.g., circuits) or combinations of elements that are capable of performing functions in a device (e.g., in a user equipment device or in a cellular network device). Processors may include, for example: general purpose processors and associated memory, portions or circuits of individual processor cores, entire processor cores or processing circuit cores, processing circuit arrays or processor arrays, circuits such as ASICs (application specific integrated circuits), programmable hardware elements such as field programmable gate arrays (FPGAs), and any various combinations of the foregoing.

[0099] Channel - a medium used to transmit information from a sender (transmitter) to a receiver. It should be noted that since the characteristics of the term "channel" may vary according to different wireless protocols, the term "channel" used in the present invention may be considered to be used in a manner that conforms to the standards of the type of device to which the term is used. In some standards, the channel width may be variable (e.g., depending on device capabilities, frequency band conditions, etc.). For example, LTE may support scalable channel bandwidths of 1.4 MHz to 20 MHz. In contrast, a WLAN channel may be 22 MHz wide, while a Bluetooth channel may be 1 MHz wide. Other protocols and standards may include different definitions of channels. In addition, some standards may define and use multiple types of channels, such as different channels for uplink or downlink and / or different channels for different purposes such as data, control information, etc.

[0100] Band (or frequency band)—The term "band" has the full range of its usual meaning and includes at least a section of the spectrum (e.g., radio frequency spectrum) in which channels are used or set aside for the same purpose. In addition, "frequency band" is used to refer to any interval in the frequency domain that is bounded by lower and higher frequencies. The term may refer to a radio frequency band or some other interval of the spectrum. A radio communication signal may occupy a frequency range over which the signal is carried (or within which the signal is carried). Such a frequency range is also referred to as the bandwidth of the signal. Thus, the bandwidth refers to the difference between the upper and lower frequencies in a continuous frequency band. A frequency band may represent one communication channel, or it may be subdivided into multiple communication channels. The allocation of radio frequency ranges for different uses is a primary function of radio spectrum allocation.

[0101] Transmission Scheduling - In cellular radio communications, signal and data transmissions may be organized according to designated time units within a specific duration in which the transmission occurs. For example, in 3GPP LTE, transmissions are divided into radio frames, each of which has an equal (time) duration (e.g., 10 ms per radio frame). Radio frames in LTE may be further divided into ten subframes, each of which has an equal duration, with subframes being designated as the minimum (shortest) scheduling unit, or designated time unit for transmission. Similarly, the minimum (or shortest) scheduling unit for 5G NR (or simply NR) transmissions is referred to as a "time slot." Thus, as used herein, the term "time slot" refers to the minimum (or shortest) scheduling time unit for the wireless communication being described. However, as described above, such scheduling time units may be named differently in different communication protocols, e.g., "subframes" in LTE, etc.

[0102] Wi-Fi—The term "Wi-Fi" has the full scope of its usual meaning and includes at least wireless communication networks or RATs that are served by wireless LAN (WLAN) access points and provide connectivity to the Internet through these access points. Most modern Wi-Fi networks (or WLAN networks) are based on the IEEE 802.11 standard and are marketed under the name "Wi-Fi". Wi-Fi (WLAN) networks are distinct from cellular networks.

[0103] Automatic—refers to an action or operation performed by a computer system (e.g., software executed by a computer system) or a device (e.g., a circuit, a programmable hardware element, an ASIC, etc.) without the need for user input to directly specify or perform the action or operation. Thus, the term "automatic" is in contrast to a user manually performing or specifying an action, where the user provides input to directly perform the action. An automatic process may be initiated by input provided by a user, but subsequent actions performed "automatically" are not specified by the user, i.e., are not performed "manually," where the user specifies each action to be performed. For example, a user filling out an electronic form by selecting each field and providing input specifying information (e.g., by typing in information, selecting checkboxes, radio selections, etc.) is manually filling out the form, even though the computer system must update the form in response to the user action. The form may be automatically filled out 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 any user input specifying the answers to the fields. As indicated above, a user may invoke automatic filling out of a form, but not participate in the actual filling out of the form (e.g., the user does not manually specify the answers to the fields but rather they are automatically completed). This specification provides various examples of operations that are automatically performed in response to actions taken by a user.

[0104] Approximately - refers to a value that is close to a correct or exact value. For example, approximately can refer to a value that is within 1% to 10% of an exact (or desired) value. However, it should be noted that the actual threshold value (or tolerance) may depend on the application. For example, in some embodiments, "approximately" may mean within 0.1% of some specified or desired value, while in various other embodiments, the threshold value may be, for example, 2%, 3%, 5%, etc., depending on the expectations or requirements of a particular application.

[0105] Concurrency - refers to parallel execution or implementation, where tasks, processes, or programs are executed in an at least partially overlapping manner. For example, concurrency can be achieved using "strong" or strict parallelism, where tasks are executed (at least partially) in parallel on respective computing elements, or using "weak parallelism", where tasks are executed in an interleaved manner (e.g., by time multiplexing of execution threads).

[0106] Station (STA)—The term "station" herein refers to any device that has the ability to communicate wirelessly (e.g., using the 802.11 protocol). A station may be a laptop, desktop PC, PDA, access point, or Wi-Fi phone, or any type of device similar to a UE. A STA may be fixed, mobile, portable, or wearable. Generally speaking, in wireless networking terminology, a station (STA) broadly encompasses any device that has wireless communication capabilities, and the terms station (STA), wireless client (UE), and node (BS) are therefore often used interchangeably.

[0107] Configured to - Various components may be described as being "configured to" perform one or more tasks. In such environments, "configured to" is a broad statement that generally means "having a structure" that performs one or more tasks during operation. Thus, a component can be configured to perform a task even when the component is not currently performing the task (e.g., a set of electrical conductors can be configured to electrically connect a module to another module even when the two modules are not connected). In some contexts, "configured to" can be a broad statement that generally means "having a structure" that performs one or more tasks during operation. Thus, the component can be configured to perform a task even when the component is not currently turned on. Typically, the circuitry that forms the structure corresponding to "configured to" may include hardware circuitry.

[0108] For ease of description, various components may be described as performing one or more tasks. Such descriptions should be interpreted as including the phrase "configured to". The description of a component being configured to perform one or more tasks is expressly intended to not invoke the interpretation of the sixth paragraph of Section 112 of Title 35 of the United States Code on that component.

[0109] Figure 1 and Figure 2 -Exemplary Communication System

[0110] Figure 1 An exemplary (and simplified) wireless communication system according to some embodiments is shown. Note that Figure 1 The system is only one example of a possible system, and the embodiment may be implemented in any of a variety of systems as desired.

[0111] As shown, the exemplary wireless communication system includes base stations 102A to 102N, also collectively referred to as multiple base stations 102 or base stations 102. Figure 1As shown, base station 102A communicates with one or more user equipment 106A to 106N via a transmission medium. Each user equipment may be referred to herein as a "user equipment" (UE) or a UE device. Therefore, user equipment 106A to 106N are referred to as UEs or UE devices, and are also collectively referred to as UE 106 or UE 106. Various UE devices in the UE devices may use SRS-based downlink TCI according to various embodiments disclosed herein.

[0112] Base station 102A may be a base transceiver station (BTS) or a cell site, and may include hardware that enables wireless communication with UEs 106A to 106N. Base station 102A may also be equipped to communicate with network 100, such as a core network of a cellular service provider, a telecommunications network such as a public switched telephone network (PSTN) and / or the Internet, a neutral host or various CBRS (Citizen Broadband Radio Service) deployments, and various possibilities. Therefore, base station 102A may facilitate communication between user devices and / or between user devices and network 100. In particular, cellular base station 102A may provide UE 106 with various communication capabilities such as voice, SMS and / or data services. The communication area (or coverage area) of a base station may be referred to as a "cell". It should also be noted that a "cell" may also refer to a logical identity for a given coverage area at a given frequency. In general, any independent cellular wireless coverage area may be referred to as a "cell". In such a case, a base station may be located at a specific intersection of three cells. In this uniform topology, a base station may serve three 120-degree beam width areas called cells. Moreover, for carrier aggregation, small cells, relays, etc. can all represent cells. Therefore, especially in carrier aggregation, there may be primary cells and secondary cells that can serve at least partially overlapping coverage areas but are served on different corresponding frequencies. For example, a base station may serve any number of cells, and the cells served by the base station may or may not be arranged in parallel (e.g., a remote radio head). Also as used herein, with respect to a UE, sometimes a base station may be considered to represent a network, taking into account the uplink and downlink communications of the UE. Therefore, a UE that communicates with one or more base stations in a network may also be interpreted as a UE that communicates with the network, and may also be considered to be at least a part of the UE communicating on or through the network.

[0113] The base station 102 and the user equipment may be configured to communicate over a transmission medium using any of a variety of radio access technologies (RATs), also referred to as wireless communication technologies or telecommunication standards, such as GSM, UMTS (WCDMA), LTE, LTE-Advanced (LTE-A), LAA / LTE-U, 5G-NR (abbreviated as NR), 3GPP2 CDMA2000 (e.g., 1xRTT, 1xEV-DO, HRPD, eHRPD), Wi-Fi, WiMAX, etc. It is noted that if the base station 102 is implemented in the context of LTE, it may alternatively be referred to as an "eNodeB" or "eNB". It is noted that if the base station 102A is implemented in the context of 5G NR, it may alternatively be referred to as a "gNodeB" or "gNB". In some embodiments, as described herein, the base station 102 may transmit a downlink TCI based on SRS. Depending on a given application or specific considerations, for convenience, some different RATs may be functionally grouped according to overall defining characteristics. For example, all cellular RATs may be collectively considered to represent a first (form / type) RAT, while Wi-Fi communications may be considered to represent a second RAT. In other cases, individual cellular RATs may be individually considered to be different RATs. For example, when distinguishing between cellular communications and Wi-Fi communications, "first RAT" may collectively refer to all cellular RATs considered, while "second RAT" may refer to Wi-Fi. Similarly, when applicable, different forms of Wi-Fi communications (e.g., over 2.4 GHz vs. over 5 GHz) may be considered to correspond to different RATs. In addition, cellular communications performed according to a given RAT (e.g., LTE or NR) may be distinguished from each other based on the spectrum in which those communications are performed. For example, LTE or NR communications may be performed on a primary licensed spectrum as well as on an unlicensed spectrum and / or a secondary spectrum of spectrum assigned to a Citizen Broadband Radio Service (CBRS). In general, the use of various terms and expressions will always be clearly indicated with respect to the context of the various applications / implementations considered and in that context.

[0114] As shown, base station 102A may also be configured to communicate with network 100 (e.g., a core network of a cellular service provider, a telecommunications network such as a public switched telephone network (PSTN), and / or the Internet, among various possibilities). Thus, base station 102A may facilitate communications between user devices and / or between user devices and network 100. In particular, cellular base station 102A may provide UE 106 with various communication capabilities such as voice, SMS, and / or data services. Base station 102A and other similar base stations (such as base stations 102B ... 102N) operating according to the same or different cellular communication standards may thus be provided as a network of cells that may provide continuous or nearly continuous overlapping services to UE 106A-106N and similar devices over a geographic area via one or more cellular communication standards.

[0115] Thus, although base station 102A may function as Figure 1 106A-106N, but each UE 106 may also be able to receive signals from (and possibly be within communication range of) one or more other cells (which may be provided by base stations 102B-102N and / or any other base stations), which may be referred to as "neighboring cells." Such cells may also be able to facilitate communications between user devices and / or between user devices and network 100. Such cells may include "macro" cells, "micro" cells, "pico" cells, and / or cells of any various other granularity of service area size. For example, in Figure 1 The base stations 102A-102B shown in FIG. 1 may be macro cells, while the base station 102N may be a micro cell. Other configurations are also possible.

[0116] In some embodiments, base station 102A may be a next generation base station, such as a 5G New Radio (5G NR) base station or "gNB". In some embodiments, a gNB may be connected to a legacy Evolved Packet Core (EPC) network and / or to a New Radio Communications Core (NRC) network. In addition, a gNB cell may include one or more transmission and reception points (TRPs). In addition, a UE capable of operating in accordance with 5G NR may connect to one or more TRPs within one or more gNBs.

[0117] As described above, the UE 106 may be capable of communicating using multiple wireless communication standards. For example, the UE may be configured to communicate using any or all of the 3GPP cellular communication standards (such as LTE or NR) or 3GPP2 cellular communication standards (such as cellular communication standards in the CDMA2000 family of cellular communication standards). The base station 102 and other similar base stations operating according to the same or different cellular communication standards may thus be provided as one or more cell networks that may provide continuous or nearly continuous overlapping services to the UE 106 and similar devices over a wide geographic area via one or more cellular communication standards.

[0118] UE 106 may also or alternatively be configured to use WLAN, BLUETOOTH TM 、BLUETOOTH TM The UE 106 may communicate with the network 100 through one or more base stations or through other devices, stations, or any apparatus not explicitly shown but considered to be part of the network 100. Therefore, the communication between the UE 106 and the network may be interpreted as the communication between the UE 106 and one or more network nodes that are considered to be part of the network, and may interact with the UE 106 to communicate with the UE 106, and in some cases affect at least some communication parameters and / or the use of communication resources of the UE 106.

[0119] In addition, Figure 1 As shown in FIG. 1 , at least some of the UEs 106 (e.g., UEs 106D and 106E) may represent vehicles that communicate with each other and with the base station 102A, for example, via cellular communications such as 3GPP LTE and / or 5G-NR. Additionally, UE 106F may represent pedestrians that are communicating and / or interacting with the vehicles represented by UEs 106D and 106E in a similar manner. In the context of vehicle-to-everything (V2X) communications (such as communications specified by 3GPP TS 22.185 V 14.3.0, etc.), disclosed in Figure 1 Other aspects of vehicles communicating in the network illustrated in FIG.

[0120] Figure 2An exemplary user equipment 106 (e.g., one of devices 106A through 106N) is shown communicating with a base station 102 and an access point 112 in accordance with some embodiments. The UE 106 may be a device having cellular communication capabilities and non-cellular communication capabilities (e.g., BLUETOOTH TM , Wi-Fi, etc.), such as a mobile phone, a handheld device, a computer or a tablet computer, or almost any type of wireless device. UE 106 may include a processor configured to execute program instructions stored in a memory. UE 106 may execute any of the method implementation schemes described in the present invention by executing such stored instructions. Alternatively or in addition, UE 106 may include a programmable hardware element, such as a field programmable gate array (FPGA) configured to execute any of the method implementation schemes described in the present invention or any part of any of the method implementation schemes described in the present invention. UE 106 may be configured to communicate using any one of a plurality of wireless communication protocols. For example, UE 106 may be configured to communicate using two or more of CDMA 2000, LTE, LTE-A, NR, WLAN, or GNSS. Other combinations of wireless communication standards are also possible.

[0121] UE 106 may include one or more antennas for communicating using one or more wireless communication protocols according to one or more RAT standards, such as those previously described above. In some embodiments, UE 106 may share one or more parts of a receive chain and / or transmit chain between multiple wireless communication standards. The shared radio component may include a single antenna, or may include multiple antennas for performing wireless communication (e.g., for MIMO). Alternatively, UE 106 may include an independent transmit chain and / or receive chain (e.g., including independent antennas and other radio components) for each wireless communication protocol configured to communicate with it. As another alternative, UE 106 may include one or more radio components or radio circuits shared between multiple wireless communication protocols, and one or more radio components used exclusively by a single wireless communication protocol. For example, UE 106 may include a shared radio component for communicating using one of LTE or CDMA2000 1xRTT or NR, and a radio component for communicating using Wi-Fi and BLUETOOTH. TM Independent radio components for each of the communications. Other configurations are also possible.

[0122] Figure 3 - Block diagram of an exemplary UE

[0123] Figure 3A block diagram of an exemplary UE 106 according to some embodiments is shown. As shown, the UE 106 may include a system on chip (SOC) 300, which may include parts for various purposes. For example, as shown, the SOC 300 may include a processor 302 that can execute program instructions for the UE 106, and a display circuit 304 that can perform graphics processing and provide display signals to a display 360. The processor 302 may also be coupled to a memory management unit (MMU) 340, and / or other circuits or devices (such as display circuit 304, radio circuit 330, connector I / F 320 and / or display 360), which may be configured to receive addresses from the processor 302 and convert those addresses into locations in a memory (e.g., memory 306, read-only memory (ROM) 350, NAND flash memory 310). The MMU 340 may be configured to perform memory protection and page table conversion or setup. In some embodiments, the MMU 340 may be included as part of the processor 302.

[0124] As shown, SOC 300 may be coupled to various other circuits of UE 106. For example, UE 106 may include various types of memory (e.g., including NAND flash memory 310), a connector interface 320 (e.g., for coupling to a computer system), a display 360, and wireless communication circuits (e.g., for LTE, LTE-A, NR, CDMA2000, BLUETOOTH TM , Wi-Fi, GPS, etc.). The UE device 106 may include at least one antenna (e.g., 335a), and may include multiple antennas (e.g., as shown by antennas 335a and 335b) for performing wireless communications with base stations and / or other devices. Antennas 335a and 335b are shown by way of example, and the UE device 106 may include fewer or more antennas. In general, one or more antennas are collectively referred to as antennas 335. For example, the UE device 106 may use antenna 335 to perform wireless communications with the aid of radio circuitry 330. As described above, in some embodiments, the UE may be configured to perform wireless communications using multiple wireless communication standards.

[0125] As further described herein, the UE 106 (and / or the base station 102) may include hardware and software components for implementing at least the method for the UE 106 to use the SRS-based downlink TCI as further described herein. The processor 302 of the UE device 106 may be configured to implement part or all of the methods described herein, for example, by executing program instructions stored on a memory medium (e.g., a non-transitory computer-readable memory medium). In other embodiments, the processor 302 may be configured as a programmable hardware element, such as an FPGA (field programmable gate array) or as an ASIC (application-specific integrated circuit). In addition, the processor 302 may be coupled to a processor such as a processor 106, such as a processor 106, or a processor 106. Figure 3 Other components are shown and / or may interoperate with other components to use SRS-based downlink TCI according to various embodiments disclosed herein. Processor 302 may also implement various other applications and / or end-user applications running on UE 106.

[0126] In some embodiments, the radio circuit 330 may include a separate controller dedicated to controlling communications for each respective RAT standard. Figure 3 As shown, the radio circuit 330 may include a Wi-Fi controller 356, a cellular controller (eg, LTE and / or NR controller) 352, and a BLUETOOTH controller. TM Controller 354, and in at least some embodiments, one or more or all of these controllers may be implemented as respective integrated circuits (referred to as ICs or chips) that communicate with each other and with SOC 300 (more specifically, with processor 302). For example, Wi-Fi controller 356 may communicate with cellular controller 352 via a cell-ISM link or WCI interface, and / or BLUETOOTH TM The controller 354 may communicate with the cellular controller 352 via a cell-ISM link or the like. Although three separate controllers are shown within the radio circuit 330, other embodiments with fewer or more similar controllers for various different RATs may be implemented in the UE device 106. For example, in Figure 5 At least one exemplary block diagram illustrating some embodiments of the cellular controller 352 is shown in FIG. 1 and will be further described below.

[0127] Figure 4 - Block diagram of an exemplary base station

[0128] Figure 4 1 shows a block diagram of an exemplary base station 102 according to some embodiments. Note that Figure 4The base station of is only one example of a possible base station. As shown, the base station 102 may include a processor 404 that may execute program instructions for the base station 102. The processor 404 may also be coupled to a memory management unit (MMU) 440 or other circuit or device, which may be configured to receive addresses from the processor 404 and convert these addresses to locations in memory (e.g., memory 460 and read-only memory (ROM) 450).

[0129] Base station 102 may include at least one network port 470. Network port 470 may be configured to couple to a telephone network and provide access to the telephone network described above. Figure 1 and Figure 2 The network port 470 may be configured to couple to a plurality of devices such as the UE device 106 of the telephone network described in the embodiment of the present invention. The network port 470 (or an additional network port) may also be configured or alternatively configured to couple to a cellular network, such as a core network of a cellular service provider. The core network may provide mobility-related services and / or other services to a plurality of devices such as the UE device 106. In some cases, the network port 470 may be coupled to the telephone network via the core network, and / or the core network may provide the telephone network (e.g., in other UE devices served by the cellular service provider).

[0130] The base station 102 may include at least one antenna 434, and may include multiple antennas (e.g., shown by antennas 434a and 434b) for wireless communication with mobile devices and / or other devices. Antennas 434a and 434b are shown as examples, and the base station 102 may include fewer or more antennas. In general, one or more antennas that may include antenna 434a and / or antenna 434b are collectively referred to as antenna 434. Antenna 434 may be configured to operate as a wireless transceiver, and may be further configured to communicate with UE device 106 via radio circuit 430. Antenna 434 may communicate with radio circuit 430 via communication chain 432. Communication chain 432 may be a receiving chain, a transmitting chain, or both. Radio circuit 430 may be designed to communicate via various wireless telecommunication standards, including but not limited to LTE, LTE-A, 5G-NR (or NR for short), WCDMA, CDMA2000, etc. The processor 404 of the base station 102 may be configured to implement part or all of the methods described herein, for example by executing program instructions stored on a memory medium (e.g., a non-transitory computer-readable memory medium) to enable the base station 102 to communicate with a UE device that uses an SRS-based downlink TCI as disclosed herein. Alternatively, the processor 404 may be configured as a programmable hardware element such as an FPGA (field programmable gate array) or as an ASIC (application-specific integrated circuit) or a combination thereof. In the case of certain RATs (e.g., Wi-Fi), the base station 102 may be designed as an access point (AP), in which case the network port 470 may be implemented to provide access to a wide area network and / or one or more local area networks, for example, it may include at least one Ethernet port, and the radio component 430 may be designed to communicate according to the Wi-Fi standard. The base station 102 may operate according to the various methods and embodiments disclosed herein to transmit an SRS-based downlink TCI.

[0131] Figure 5 - Block diagram of an exemplary cellular communication circuit

[0132] Figure 5 An exemplary simplified block diagram of an exemplary cellular controller 352 according to some embodiments is shown. Note that Figure 5The block diagram of the cellular communication circuitry of is only one example of possible cellular communication circuitry; other circuitry, such as circuitry that includes or is coupled to sufficient antennas for different RATs to perform uplink activities using separate antennas, or circuitry that includes or is coupled to fewer antennas, such as circuitry that can be shared between multiple RATs, is also possible. According to some embodiments, the cellular communication circuitry 352 may be included in a communication device such as the communication device 106 described above. As described above, the communication device 106 may be a user equipment (UE) device, a mobile device or mobile station, a wireless device or wireless station, a desktop computer or computing device, a mobile computing device (e.g., a laptop, notebook, or portable computing device), a tablet computer, and / or a combination of devices, among other devices.

[0133] The cellular communication circuitry 352 may be (e.g., communicatively; directly or indirectly) coupled to one or more antennas, such as antennas 335a-b and 336 as shown. In some embodiments, the cellular communication circuitry 352 may include dedicated receive chains for multiple RATs (including and / or coupled to (e.g., communicatively; directly or indirectly) dedicated processors and / or radio components (e.g., a first receive chain for LTE and a second receive chain for 5G NR). For example, Figure 5 As shown, the cellular communication circuit 352 may include a first modem 510 and a second modem 520. The first modem 510 may be configured for communication according to a first RAT (e.g., such as LTE or LTE-A), and the second modem 520 may be configured for communication according to a second RAT (e.g., such as 5G NR).

[0134] As shown, the first modem 510 may include one or more processors 512 and a memory 516 in communication with the processor 512. The modem 510 may communicate with a radio frequency (RF) front end 530. The RF front end 530 may include circuits for transmitting and receiving radio signals. For example, the RF front end 530 may include a receiving circuit (RX) 532 and a transmitting circuit (TX) 534. In some embodiments, the receiving circuit 532 may communicate with a downlink (DL) front end 550, which may include circuits for receiving radio signals via an antenna 335a.

[0135] Similarly, the second modem 520 may include one or more processors 522 and a memory 526 in communication with the processor 522. The modem 520 may communicate with the RF front end 540. The RF front end 540 may include circuits for transmitting and receiving radio signals. For example, the RF front end 540 may include a receiving circuit 542 and a transmitting circuit 544. In some embodiments, the receiving circuit 542 may communicate with the DL front end 560, which may include circuits for receiving radio signals via the antenna 335b.

[0136] In some embodiments, the switch 570 may couple the transmit circuit 534 to an uplink (UL) front end 572. In addition, the switch 570 may couple the transmit circuit 544 to the UL front end 572. The UL front end 572 may include circuitry for transmitting radio signals via the antenna 336. Thus, when the cellular communication circuit 352 receives an instruction to transmit according to a first RAT (e.g., via a transmit chain including the transmit circuit 534 and the UL front end 572) supported by the first modem 510, the switch 570 may be switched to a first state that allows the first modem 510 to transmit signals according to the first RAT (e.g., via a transmit chain including the transmit circuit 534 and the UL front end 572). Similarly, when the cellular communication circuit 352 receives an instruction to transmit according to a second RAT (e.g., via a transmit chain including the transmit circuit 544 and the UL front end 572) supported by the second modem 520, the switch 570 may be switched to a second state that allows the second modem 520 to transmit signals according to the second RAT (e.g., via a transmit chain including the transmit circuit 544 and the UL front end 572).

[0137] As described herein, the first modem 510 and / or the second modem 520 may include hardware and software components for implementing any of the various features and techniques described herein. For example, by executing program instructions stored on a memory medium (e.g., a non-transitory computer-readable memory medium), the processors 512, 522 may be configured to implement part or all of the features described herein. Alternatively (or in addition), the processors 512, 522 may be configured as programmable hardware elements, such as an FPGA (field programmable gate array) or as an ASIC (application-specific integrated circuit). Alternatively (or in addition), in combination with one or more of the other components 530, 532, 534, 540, 542, 544, 550, 570, 572, 335, and 336, the processors 512, 522 may be configured to implement part or all of the features described herein.

[0138] In addition, as described herein, the processors 512, 522 may include one or more processing elements. Thus, the processors 512, 522 may include one or more integrated circuits (ICs) configured to perform the functions of the processors 512, 522. In addition, each integrated circuit may include circuits (e.g., first circuits, second circuits, etc.) configured to perform the functions of the processors 512, 522.

[0139] In some embodiments, the cellular communication circuit 352 may include only one transmit / receive chain. For example, the cellular communication circuit 352 may not include the modem 520, the RF front end 540, the DL front end 560, and / or the antenna 335b. As another example, the cellular communication circuit 352 may not include the modem 510, the RF front end 530, the DL front end 550, and / or the antenna 335a. In some embodiments, the cellular communication circuit 352 may also not include the switch 570, and the RF front end 530 or the RF front end 540 may communicate with the UL front end 572, for example, directly.

[0140] SRS-based TCI

[0141] One possible way to reduce beam reporting delay is to support SRS-based downlink beam indication or downlink TCI. The UE can transmit multiple SRSs with different beams, and then the base station can indicate one of the SRSs to the UE in the TCI. Based on the SRS indication, the UE can use the same beam as the UE uses to transmit the SRS to receive the downlink signal. This means that the UE does not need to report the beam quality; instead, the base station can perform the necessary beam measurements. Therefore, when the SRS is indicated, the UE can apply the same beam as the beam used to transmit the uplink signal to receive the downlink signal. It should be noted that multiple SRSs may represent periodic and / or semi-persistent SRSs (i.e., SRSs transmitted according to semi-persistent scheduling), or they may represent non-periodic SRSs. Non-periodic SRSs are not transmitted according to any predefined periodicity or repetition schedule. There are several issues to consider in terms of how SRS-based TCI can be implemented.

[0142] First question

[0143] Figure 6 A timing diagram illustrating SRS signaling, PDCCH transmission, PDSCH transmission, and corresponding beam patterns is shown. In one sense, Figure 6 Different examples of how a UE can use different beams to transmit SRS are shown. Figure 6 As shown, beam 604 is used to transmit SRS 602, beam 608 is used to transmit SRS 606, beam 612 is used to transmit SRS 610, and beam 618 is used to transmit SRS 616. Figure 6In the example, PDCCH 614 is received between SRS 610 and SRS 616, and PDSCH 620 is received after SRS 616. Figure 6 As shown in , the TCI in the PDCCH is based on SRS, and since multiple instances of SRS are transmitted using different corresponding beams, the question of which beam the UE uses to receive PDSCH 620 remains unresolved. In other words, since the UE may apply different beams in different SRS transmission instances, the behavior of the UE for receiving downlink signals when SRS is indicated remains to be defined. In some embodiments, four options for defining the behavior of the UE under these conditions may be considered.

[0144] According to the first option, the timing of SRS and downlink beam reception of the corresponding PDSCH can be identified. In this case, after the SRS-based TCI takes effect, the UE can apply the same beam as the beam used by the UE to transmit the SRS in a specified number (K) of time slots before receiving the corresponding downlink channel. The specified number (e.g., K) can be defined according to one of the following conditions:

[0145] K is predefined, such as 0, 4, etc.

[0146] K is configured by higher layer signaling (e.g., RRC signaling); or

[0147] K is reported by UE capability signaling.

[0148] exist Figure 8 This situation is shown in Figure 8 1 shows a timing diagram illustrating SRS signaling, PDCCH transmission, and PDSCH transmission when a beam is used based on the timing of SRS and downlink beam reception of the corresponding PDSCH. Figure 8 As shown, beam 804 is used to transmit SRS 802, beam 808 is used to transmit SRS 806, beam 812 is used to transmit SRS 810, and beam 818 is used to transmit SRS 816. PDCCH 814 is received between SRS 810 and SRS 816, and PDSCH 820 is received after SRS 816. Figure 8 In , SRS 816 is transmitted a specified number (K) of time slots before PDSCH 820, so the beam 818 used by the UE to transmit SRS 816 is the same as the beam 822 used by the UE to receive PDSCH 820.

[0149] According to the second option, the timing of SRS and downlink beam reception corresponding to the PDCCH can be identified. In this case, after the SRS-based TCI takes effect, the UE can apply the same beam as the beam used for SRS transmission within a specified number (K) of time slots before receiving the scheduled PDCCH. The specified number (e.g., K) can be defined according to one of the following conditions:

[0150] K is predefined, such as 0, 4;

[0151] K is configured by higher layer signals; or

[0152] K is reported by UE capability signaling.

[0153] exist Fig. 9 This situation is shown in Fig. 9 1 shows a timing diagram illustrating SRS signaling, PDCCH transmission, and PDSCH transmission when a beam is used based on the timing of SRS and downlink beam reception of the corresponding PDCCH. Fig. 9 As shown, beam 904 is used to transmit SRS 902, beam 908 is used to transmit SRS 906, beam 912 is used to transmit SRS 910, and beam 918 is used to transmit SRS 916. PDCCH 914 is received between SRS 910 and SRS 916, and PDSCH 920 is received after SRS 916. Fig. 9 In , the SRS 910 is transmitted a specified number (K) of time slots before the PDCCH 914, so the beam 912 used by the UE to transmit the SRS 910 is the same as the beam 922 used by the UE to receive the PDSCH 920.

[0154] According to the third option, when periodic SRS or semi-persistent SRS is configured in the TCI state, the UE may not change the spatial transmission filter when not indicated by higher layer signaling. The UE may not need to check the beam used for SRS resources and does not need to define an offset. The UE may apply the same beam as the beam used to transmit SRS to receive the downlink signal indicated by the SRS-based TCI. As an extension, the UE may also expect that only periodic and / or semi-persistent SRS are indicated in the TCI state. Fig.10 This situation is shown in Fig.10 1 shows a timing diagram illustrating SRS signaling, PDCCH transmission, and PDSCH transmission when the same beam is used for all SRS transmissions and downlink channel receptions. Fig.10As shown, beam 1004 is used to transmit SRS 902, beam 1008 is used to transmit SRS 1006, beam 1012 is used to transmit SRS 1010, and beam 1018 is used to transmit SRS 1016. PDCCH 1014 is received between SRS 1010 and SRS 1016, and PDSCH 1020 is received after SRS 1016. Fig.10 As shown, beams 1004 , 1008 , 1012 , and 1018 used by the UE to transmit SRS 1002 , 1006 , 1010 , and 1016 , respectively, are identical, and they are also identical to beam 1022 used by the UE to receive PDSCH 1020 .

[0155] According to the fourth option, only non-periodic SRS (as SRS) can be configured in the TCI state. As mentioned above, in contrast to periodic and / or semi-persistent SRS (SRS transmitted according to semi-persistent scheduling), non-periodic SRS is not transmitted according to any predefined periodicity or repetition schedule. In the case where the SRS is non-periodic, before receiving the downlink signal, the UE may receive the downlink signal following the spatial transmission filter for the most recently transmitted SRS. That is, when only non-periodic SRS is indicated to the UE in the TCI, the UE may use the SRS indication to indicate that the UE is to use the same beam as the beam used by the UE to transmit the most recent (non-periodic) SRS to receive the downlink signal.

[0156] For all four options, when the spatial relationship information for SRS (e.g., the number of time slots as described above) can be configured, when SRS is configured in the TCI state of the UE, the UE can follow the latest indicated spatial relationship information of the SRS to receive the corresponding downlink channel. Alternatively, the spatial relationship information of the SRS may not be configured in the TCI state.

[0157] Second question

[0158] As currently specified, for control resource set (CORESET) 0, the CSI-RS indicated in the TCI is expected to be quasi co-located (QCL) with one synchronization signal block (SSB), and the UE is expected to monitor search space (SS) 0 and CORESET 0 opportunities associated with that SSB. It should be noted that in NR, a CORESET is a set of physical resources (e.g., a specific region of the downlink resource grid) and a set of parameters used to carry PDCCH / DCI. It can be considered equivalent to the LTE PDCCH region (the first 1, 2, 3, 4 OFDM symbols in a subframe). However, in the LTE PDCCH region, the PDCCH is distributed across the entire channel bandwidth, while the NR CORESET region is localized to a specific region in the frequency domain.

[0159] Figure 7 A timing diagram illustrating the SSB and SS / CORESET and TCI indications is shown. Figure 7 In FIG. 7 , the first instance (706) of CORESET 0 is linked to SSB 0 (702), which means that they are expected to share the same beam. However, the second instance (714) of CORESET 0 is linked to SSB 1 (710), and similar to the first instance, they are expected to share the same beam. Therefore, beam selection for this case may be problematic. When the TCI indication of CORESET 0 (716) is based on SRS, it is necessary to define the monitoring occasions of SS / CORESET 0. In some embodiments, two options for defining the monitoring occasions of SS / CORESET 0 may be considered.

[0160] According to a first option, a TCI state with SRS as the source reference signal may not be configured for CORESET 0. As a further extension, such a TCI state may not be configured for any CORESET.

[0161] According to the second option, when SRS is indicated in the TCI state of CORESET 0, the spatial relationship information of SRS may be based on one SSB, i.e. configured for one of the SSBs. The UE may monitor the SS / CORESET 0 associated with the SSB until there is a new TCI indication for CORESET 0 or until a PDCCH command does not initiate / trigger a random access channel (RACH) procedure. Fig.11 This situation is shown in Fig.11 FIG. 2 shows a timing diagram illustrating SSB and SS / CORESET 0 and TCI indication when the UE monitors SS / CORESET 0. Fig.11 As shown, a first instance (1104) of CORESET 0 is linked to SSB 0 (1102), and a second instance (1108) of CORESET 0 is linked to SSB 1 (1106). The TCI indication (1110) of CORESET 0 includes an SRS indication, and the spatial relationship for the SRS is based on SSB 0. Therefore, the UE can monitor SS / CORESET 0 (1106) associated with SSB 0 (1102).

[0162] The third question

[0163] Several types of SRS are currently defined, such as SRS for codebook-based transmission, SRS for non-codebook-based transmission, SRS for antenna switching, and SRS for beam management, to name a few. SRS for antenna switching involves downlink CSI measurement, where the UE can apply different antenna ports to different SRS source feeds, and the base station can derive the downlink CSI from the measured reference signal. SRS for beam management is used for uplink beam measurement. Since there are several different types of SRS, the QCL assumptions of the UE for different types of SRS need to be considered. Another consideration is whether the SRS and the configured downlink channel can be transmitted in different serving cells.

[0164] Regarding the type of SRS that can be indicated in the TCI state, three options can be considered. According to the first option, only the SRS used for beam management can be indicated. According to the second option, only the SRS used for beam management and / or the SRS used for codebook-based and non-codebook-based transmission can be indicated. According to the third option, all different types of SRS can be indicated.

[0165] The TCI state with SRS as the source reference signal can be configured for the TCI state of all or a subset of a set of specified downlink signals, which include but are not limited to PDSCH, CSI-RS with repetition = on, CSI-RS with repetition = off, CSI-RS configured with TRS information, CSI-RS without repetition and not configured with TRS information, and CORESET.

[0166] Regarding the QCL parameters that can be indicated by the SRS in the TCI state, two options can be considered. According to the first option, the SRS can only indicate the spatial reception parameters. According to the second option, the SRS can indicate all QCL parameters, including spatial reception parameters, delay offset, Doppler shift, delay spread, and Doppler spread.

[0167] Regarding when to configure SRS in TCI state, two options may be considered. According to the first option, the SRS may be in the same serving cell as the indicated downlink signal. According to the second option, the SRS may be in the same serving cell as the indicated downlink signal, or may be in a different serving cell. The serving cell index for SRS may be configured by higher layer signaling (e.g., RRC signaling). As an extension, the bandwidth part (BWP) index for SRS may also be configured by / through higher layer signaling.

[0168] The fourth question

[0169] For a UE with multiple panels, which may be able to transmit and / or receive signals from multiple base stations simultaneously, the base station's assumption about the simultaneous reception of multiple downlink signals needs to be considered when indicating SRS in the TCI state. For example, it may be necessary to determine how a base station (e.g., a gNB) can identify that a downlink signal can be received by multiple panels. Regarding the base station's assumption about the simultaneous reception of multiple downlink signals, three options can be considered.

[0170] According to the first option, for a TCI state with SRS as the source reference signal, the base station may assume that downlink signals with different TCI states cannot be received simultaneously.

[0171] According to the second option, for the TCI state with SRS as the source reference signal, the base station may assume that when the source SRS is configured in different resource sets with the same purpose, downlink signals with different TCI states can be received simultaneously. Fig.12 This situation is shown in Fig.12 FIG. 4 shows a timing diagram illustrating SRS signaling, PDCCH transmission, and PDSCH transmission when source SRSs are configured in different resource sets having the same purpose. Fig.12 As shown, SRS 1 (1202) is transmitted using resource set 1, and SRS 2 (1204) is transmitted using resource set 2. Scheduled PDCCH 1206 (single or multiple) may include TCI 1 based on SRS 1 and TCI 2 based on SRS 2. Scheduled PDSCH 1210 is received by the UE simultaneously from two TCI states.

[0172] According to the third option, for TCI states with SRS as source reference signal, the base station may assume that downlink signals with different TCI states can be received simultaneously when the source SRS is configured in different panel IDs with the same purpose. The panel ID may be explicitly defined / configured by higher layer signaling (e.g., via RRC signaling), or it may be implicitly derived based on the latest beam report and the spatial relationship information indicated for the SRS. Fig.13 This situation is shown in Fig.13 FIG. 2 shows a timing diagram illustrating SRS signaling, PDCCH transmission, and PDSCH transmission when source SRSs are configured in different panel IDs having the same purpose. Fig.13 As shown, SRS 1 (1302) is configured with panel ID 1 and SRS 2 (1304) is configured with panel ID 2. Scheduled PDCCH 1306 (single or multiple) may include TCI 1 based on SRS 1 and TCI 2 based on SRS 2. Scheduled PDSCH 1310 is received by the UE from both TCI states simultaneously.

[0173] It is understood that the use of personally identifiable information should be subject to privacy policies and practices that are generally recognized to meet or exceed industry or government requirements for maintaining user privacy. Specifically, personally identifiable information data should be managed and processed to minimize the risk of unintentional or unauthorized access or use, and the nature of the authorized use should be clearly stated to users.

[0174] Embodiments of the present invention may be implemented in any of a variety of forms. For example, in some embodiments, the present invention may be implemented as a computer-implemented method, a computer-readable storage medium, or a computer system. In other embodiments, one or more custom-designed hardware devices such as ASICs may be used to implement the present invention. In other embodiments, one or more programmable hardware elements such as FPGAs may be used to implement the present invention.

[0175] In some embodiments, a non-transitory computer-readable storage medium (e.g., a non-transitory storage element) may be configured to store program instructions and / or data, wherein if the program instructions are executed by a computer system, the computer system is caused to perform a method, such as any of the method embodiments described herein, or any combination of the method embodiments described herein, or any subset of any method embodiments described herein, or any combination of such subsets.

[0176] In some embodiments, a device (e.g., a UE) may be configured to include a processor (or a group of processors) and a memory medium (or a memory element), wherein the memory medium stores program instructions, wherein the processor is configured to read and execute the program instructions from the memory medium, wherein the program instructions are executable to implement any of the various method implementations described herein (or any combination of the method implementations described herein, or any subset of any method implementations described herein or any combination of such subsets). The device may be implemented in any of various forms.

[0177] Although the above embodiments have been described in considerable detail, numerous variations and modifications will become apparent to those skilled in the art once the above disclosure is fully appreciated. It is intended that the following claims be interpreted to encompass all such variations and modifications.

Claims

1. A method for wireless communication between a device and a base station, the method comprising: Continuously transmitting a plurality of sounding reference signals (SRS) to a base station; receiving, from the base station in a transmission configuration indication (TCI), an indication of a first SRS of the plurality of SRSs, at least in response to the base station receiving one or more SRSs of the plurality of SRSs, wherein transmitting the plurality of SRSs comprises transmitting the first SRS using a first beam; as well as In response to at least receiving the indication of the first SRS, a downlink signal corresponding to the first SRS is received from the base station using the first beam.

2. The method according to claim 1, comprising: The first SRS is transmitted a specified number of time slots before one of: receiving the TCI from the base station; or The downlink signal is received from the base station.

3. The method according to claim 2, comprising: The TCI is received in a physical control channel corresponding to the first SRS.

4. The method according to claim 2, comprising: The downlink signal is received in a physical control channel corresponding to the first SRS.

5. The method according to claim 2, wherein: The specified number is one of the following: Predefined number; A number configured via higher layer signalling; or Reported by device capability signaling.

6. The method according to claim 1, comprising: When the plurality of SRSs are periodic or semi-persistent SRSs, each of the plurality of SRSs is transmitted using the same beam.

7. The method according to claim 1, wherein: When the plurality of SRSs are aperiodic SRSs, the first SRS is an SRS most recently transmitted before the downlink signal is received.

8. The method according to claim 1, further comprising: The first beam is identified based on the latest indicated spatial relationship information for the SRS.

9. The method according to claim 1, wherein: The TCI state with SRS as the source reference signal is not configured for one of the following: CORESET 0; or Any CORESET in CORESET.

10. The method according to claim 1, comprising: The CORESET 0 associated with a particular sync signal block is monitored until one of the following occurs: Receive new TCI; or The Physical Control Channel command does not trigger the Random Access Channel procedure.

11. The method according to claim 1, wherein: The first SRS is one of the following: SRS for beam management; SRS for codebook based transmission; SRS for non-codebook based transmission; or SRS for antenna switching.

12. The method according to claim 1, wherein: The downlink signal is one of the following: Physical data channel; Repeatedly turned on Channel State Information Reference Signal (CSI-RS); Repeatedly disabled CSI-RS; CSI-RS configured with Tracking Reference Signal (TRS) information; CSI-RS without duplication and TRS information configured; or CORESET.

13. The method according to claim 1, wherein: The first SRS indicates a quasi co-location parameter, where the quasi co-location parameter includes one or more of the following: Space receiving parameters; Delay offset; Doppler shift; Delayed expansion; or Doppler spread.

14. The method of claim 1, comprising transmitting the first SRS in one of: the same serving cell as the downlink signal; or A serving cell different from that of the downlink signal.

15. The method according to claim 14, further comprising: One or more of the following is configured via higher layer signaling: A serving cell index for the first SRS; or A bandwidth portion index for the first SRS.

16. The method according to claim 1, wherein: The base station assumes that the downlink signals can be received simultaneously based on one or more of the following situations: When the corresponding source SRS is configured in different resource sets with the same purpose; or When the corresponding source SRS is configured in different panel identifiers having the same purpose.

17. An apparatus comprising: A processor, wherein the processor is configured to cause a device to perform a method according to any one of claims 1 to 16.

18. A device comprising: radio circuitry configured to facilitate wireless communications of the device; and A processor communicatively coupled to the radio circuit and configured to cause the device to perform a method according to any one of claims 1 to 16.

19. A non-transitory memory element storing instructions executable by a processor to cause an apparatus to perform a method according to any one of claims 1 to 16.

20. A base station, comprising: radio circuitry configured to facilitate wireless communications of the base station; and a processor communicatively coupled to the radio circuitry and configured to cause the base station to: receiving, from a device, a first sounding reference signal (SRS) transmitted by the device using a first beam; transmitting, in response to at least receiving a first SRS, an indication of the first SRS in a transmission configuration indication (TCI) to cause the device to receive a downlink signal using the first beam; as well as The downlink signal is transmitted to the device.

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