Quasi-Co-location Assumptions for Aperiodic CSI-RS for Multi-TRP Operation

Abstract

The present disclosure relates to techniques for determining quasi - co - location assumptions for aperiodic channel state information reference signals for multi - transmission - reception point operation in a wireless communication system. A wireless device may establish wireless links with multiple transmission - reception points of a cellular network. The wireless device may receive downlink control information. The wireless device may determine a quasi - co - location assumption for an aperiodic channel state information reference signal for the downlink control information. If a scheduling offset of the downlink control information is below a scheduling offset threshold, the wireless device may buffer the received signal according to the quasi - co - location assumption for the aperiodic channel state information reference signal.

Description

Technical Field

[0001] This application relates to wireless communications and, more particularly, to systems, apparatuses, and methods for determining quasi - co - location assumptions for aperiodic channel state information reference signals for multi - transmission - reception point operation in a wireless communication system. Background Art

[0002] The use of wireless communication systems is growing rapidly. In recent years, wireless devices such as smart phones and tablet computers have become increasingly sophisticated. In addition to supporting telephone calls, many mobile devices (i.e., user equipment devices or UEs) now also provide access to the Internet, email, text messaging, and navigation using the Global Positioning System (GPS), and are capable of operating sophisticated applications that utilize these features. Additionally, there are many different wireless communication technologies and wireless communication standards. Some examples of wireless communication standards include GSM, UMTS (e.g., associated with the WCDMA or TD - SCDMA air interfaces), LTE, LTE - Advanced (LTE - A), NR, HSPA, 3GPP2 CDMA2000 (e.g., 1xRTT, 1xEV - DO, HRPD, eHRPD), IEEE 802.11 (WLAN or Wi - Fi), BLUETOOTH TM etc.

[0003] The introduction of an increasing number of features and functions in wireless communication devices also requires continuous improvement of wireless communication and improvement of wireless communication devices. Specifically, it is important to ensure the accuracy of the signals transmitted and received by user equipment (UE) devices (e.g., via wireless devices such as cellular phones, base stations, and relay stations used in wireless cellular communication). Additionally, increasing the functionality of UE devices can place a significant strain on the battery life of UE devices. Therefore, it is also very important to reduce the power requirements in UE device designs while allowing UE devices to maintain good transmit and receive capabilities to improve communication. Thus, improvements in this area are desired. Summary of the Invention

[0004] Embodiments of apparatuses, systems, and methods for determining quasi - co - location assumptions for aperiodic channel state information reference signals for multi - transmission - reception point operation in a wireless communication system are presented herein.

[0005] The techniques described herein can support a wireless device in aspects such as determining which quasi - co - location assumption to use for buffering received signals, e.g., in cases where the received signals include non - periodic channel state information reference signals when a scheduling offset is below a certain threshold. These techniques can include methods for determining the quasi - co - location assumption for non - periodic channel state information reference signals for each of a single downlink control information mode (e.g., when a single downlink control information transmission is provided to schedule communications for multiple transmission - reception points) and a multi - downlink control information mode (e.g., when each transmission - reception point can provide its own downlink control information to schedule communications).

[0006] According to various embodiments, these techniques can include one or more primary methods for determining the quasi - co - location assumption for non - periodic channel state information reference signals (e.g., for each of a single downlink control information mode and a multi - downlink control information mode), and one or more backup / default methods, e.g., in cases where the conditions of the primary methods are not met and / or in cases where the wireless device does not support the method for determining the quasi - co - location assumption for non - periodic channel state information reference signals. Additionally, at least in some instances, there may be cases where different methods (e.g., configured by a base station or specified by a cellular communication standard) are taken for different types of channel state information reference signals.

[0007] Note that the techniques described herein can be implemented in and / or used with several different types of devices, including but not limited to base stations, access points, mobile phones, portable media players, tablets, wearable devices, unmanned aerial vehicles, unmanned flight controllers, cars and / or motor vehicles, and various other computing devices.

[0008] This summary is intended to provide a brief overview of some of the subject matter described in this document. Accordingly, it should be understood that the above features are merely examples and should not be construed in any way as narrowing the scope or essence of the subject matter described herein. Other features, aspects, and advantages of the subject matter described herein will become apparent from the following detailed description, the drawings, and the claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] A better understanding of the subject matter can be obtained when considering the following detailed description of various embodiments in conjunction with the following drawings, in which:

[0010] Figure 1 An exemplary (and simplified) wireless communication system is shown in accordance with some embodiments;

[0011] Figure 2Illustrates an exemplary base station communicating with an exemplary wireless user equipment (UE) device according to some embodiments;

[0012] Figure 3 Illustrates an exemplary block diagram of a UE according to some embodiments;

[0013] Figure 4 Illustrates an exemplary block diagram of a base station according to some embodiments;

[0014] Figure 5 Is a flowchart showing aspects of an exemplary possible method for determining a quasi - co - location assumption for an aperiodic channel state information reference signal for multi - transmission - reception point operation in a wireless communication system;

[0015] Figure 6 Illustrates aspects of an exemplary possible PDSCH QCL assumption determination process for a single DCI mode according to some embodiments;

[0016] Figure 7 Illustrates aspects of an exemplary possible PDSCH QCL assumption determination process for a multi - DCI mode according to some embodiments;

[0017] Figure 8 And Figure 9 Illustrates aspects of an exemplary possible aperiodic CSI - RS QCL assumption determination process for a single DCI mode according to some embodiments; and

[0018] Figure 10 And Figure 11 Illustrates aspects of an exemplary possible aperiodic CSI - RS QCL assumption determination process for a multi - DCI mode according to some embodiments.

[0019] Although the features described herein are susceptible to various modifications and alternative forms, specific embodiments thereof are shown by way of example in the drawings and are described in detail herein. However, it should be understood that the drawings and the detailed description thereof are not intended to limit the present disclosure to the specific forms disclosed, but on the contrary, are intended to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the subject matter as defined by the appended claims. Detailed Description

[0020] Acronyms

[0021] Various acronyms are used throughout this disclosure. The definitions of the most prominent acronyms that may appear throughout this disclosure are as follows:

[0022] · UE: User Equipment

[0023] ·RF: Radio Frequency

[0024] ·BS: Base Station

[0025] ·GSM: Global System for Mobile Communications

[0026] ·UMTS: Universal Mobile Telecommunications System

[0027] ·LTE: Long-Term Evolution

[0028] ·NR: New Radio

[0029] ·TX: Transmission

[0030] ·RX: Reception

[0031] ·RAT: Radio Access Technology

[0032] ·TRP: Transmission and Reception Point

[0033] ·DCI: Downlink Control Information

[0034] ·CORESET: Control Resource Set

[0035] ·QCL: Quasi-Co-Located

[0036] ·CSI: Channel State Information

[0037] ·CSI-RS: Channel State Information Reference Signal

[0038] ·CQI: Channel Quality Indicator

[0039] ·PMI: Precoding Matrix Indicator

[0040] ·RI: Rank Indicator

[0041] Terms

[0042] The following is a glossary of terms that will appear in this disclosure:

[0043] Memory medium—any of various types of non-transitory memory devices or storage devices. The term "memory medium" is intended to include installation media such as CD-ROMs, floppy disks, or magnetic tape devices; computer system memory or random access memory such as DRAM, DDR RAM, SRAM, EDO RAM, Rambus RAM, etc.; non-volatile memory such as flash memory, magnetic media such as hard disk drives or optical storage devices; registers, or other similar types of memory elements, etc. The memory medium may also include other types of non-transitory memory or combinations thereof. In addition, the memory medium may be located in a first computer system that executes a program, or may be located in a different second computer system that is connected to the first computer system via a network such as the Internet. In the latter instance, 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 at different locations in different computer systems connected, for example, via a network. The memory medium may store program instructions (e.g., embodied as a computer program) that can be executed by one or more processors.

[0044] Carrier medium—the memory medium as described above, and physical transmission media such as buses, networks, and / or other physical transmission media that convey signals such as electrical, electromagnetic, or digital signals.

[0045] Computer system (or computer)—any of various types of computing or processing systems, including personal computer systems (PCs), mainframe computer systems, workstations, network appliances, Internet appliances, personal digital assistants (PDAs), television systems, grid computing systems, or other devices or combinations of devices. Generally, the term "computer system" can be broadly defined as any device (or combination of devices) that includes at least one processor that executes instructions from a memory medium.

[0046] User equipment (UE) (or "UE device")—any of various types of computer systems or devices that are mobile or portable and perform wireless communication. Examples of UE devices include mobile phones or smartphones (e.g., iPhone TM , Android TM -based phones), tablets (e.g., iPad TM , Samsung Galaxy TM ), portable gaming devices (e.g., Nintendo DS TM , PlayStation Portable TM , Gameboy Advance TM , iPhone TM) Wearable devices (e.g., smartwatches, smart glasses), laptop computers, PDAs, portable Internet devices, music players, data storage devices, other handheld devices, automobiles and / or motor vehicles, unmanned aerial vehicles (UAVs) (e.g., drones), UAV controllers (UACs), etc. Generally speaking, the term "UE" or "UE device" can be broadly defined to cover any electronic device, computing device, and / or telecommunications device (or combination of these devices) that is easily transportable by a user and capable of wireless communication.

[0047] Wireless device - Any one of various types of computer systems or devices that perform wireless communication. The wireless device can be portable (or mobile), or can be stationary or fixed in a certain location. A UE is an example of a wireless device.

[0048] Communication device - Any one of various types of computer systems or devices that perform communication, where the communication can be wired or wireless. The communication device can be portable (or mobile), or can be stationary or fixed in a certain location. A wireless device is an example of a communication device. A UE is another example of a communication device.

[0049] Base station (BS) - The term "base station" has the full scope of its ordinary meaning and at least includes a wireless communication station installed at a fixed location and used for communication as part of a wireless telephone system or radio system.

[0050] Processing element (or processor) - Refers to various elements or combinations of elements that can perform functions in a device (such as a user equipment device or a cellular network device). The processing element can include, for example: a processor and associated memory, parts or circuits of individual processor cores, entire processor cores, processor arrays, circuits such as ASICs (application-specific integrated circuits), programmable hardware elements such as field-programmable gate arrays (FPGAs), and any one of various combinations of the above.

[0051] Wi-Fi - The term "Wi-Fi" has the full scope of its ordinary meaning and at least includes a wireless communication network or RAT that is served by wireless LAN (WLAN) access points and provides 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 different from cellular networks.

[0052] Automatically - means that 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.) performs the action or operation without the action or operation being directly specified or performed through user input. Thus, the term "automatically" is contrasted with a user manually performing or specifying an operation, where the user provides input to directly perform the operation. An automatic process can be initiated by input provided by the user, but the subsequent actions that are "automatically" performed are not specified by the user, i.e., they are not performed "manually", where the user specifies each action to be performed. For example, a user filling out a spreadsheet by selecting each field and providing input to specify information (e.g., by typing information, selecting checkboxes, radio selections, etc.) is manually filling out the form, even though the computer system must update the form in response to the user's actions. The form can be filled out automatically by a computer system, where the computer system (e.g., software executed on a computer system) analyzes the fields of the form and fills out the form without any user input specifying the answers to the fields. As indicated above, the user can initiate the automatic filling of the form but does not participate in the actual filling of the form (e.g., the user does not manually specify the answers to the fields but they are completed automatically). This specification provides various examples of operations that are automatically performed in response to actions taken by the user.

[0053] Configured to - various components can be described as "configured to" perform one or more tasks. In such an environment, "configured to" is a broad statement that generally means "having" the "structure" to perform one or more tasks during operation. Thus, even when the component is not currently performing a task, the component can be configured to perform the task (e.g., a set of electrical conductors can be configured to electrically connect a module to another module even when the two modules are not connected). In some contexts, "configured to" can be a broad statement that generally means "having" the "circuitry" to perform one or more tasks during operation. Thus, even when the component is not currently powered on, the component can be configured to perform the task. Generally, the circuitry that forms the structure corresponding to "configured to" can include hardware circuitry.

[0054] For ease of description, various components can be described as performing one or more tasks. Such a description should be interpreted as including the phrase "configured to". A component described as configured to perform one or more tasks is expressly intended not to invoke the interpretation of 35 U.S.C. § 112, paragraph 6 with respect to that component.

[0055] Figure 1 and Figure 2 - Exemplary Communication System

[0056] Figure 1 illustrates an exemplary (and simplified) wireless communication system that can implement various aspects of the present disclosure according to some embodiments. Note thatFigure 1 The system is only one example of possible systems, and this implementation can be realized in any of various systems as needed.

[0057] As shown in the figure, the exemplary wireless communication system includes a base station 102 that communicates with one or more (e.g., any number) user equipments 106A, 106B, etc. up to 106N via a transmission medium. Each user equipment can be referred to herein as a “user equipment” (UE) or a UE device. Thus, the user equipment 106 is referred to as a UE or a UE device.

[0058] The base station 102 can be a transceiver base station (BTS) or a cell site and can include hardware and / or software for implementing wireless communication with the UEs 106A to 106N. If the base station 102 is implemented in the context of LTE, it can be referred to as an “eNodeB” or an “eNB”. If the base station 102 is implemented in the context of 5G NR, it can alternatively be referred to as a “gNodeB” or a “gNB”. The base station 102 can also be equipped to communicate with a network 100 (e.g., the core network of a cellular service provider, a telecommunications network such as the public switched telephone network (PSTN), and / or the Internet, as well as various possible networks). Thus, the base station 102 can facilitate communication between user equipments and / or between user equipments and the network 100. The communication area (or coverage area) of a base station can be referred to as a “cell”. Also as used herein, with respect to a UE, a base station can sometimes be considered to represent the network when considering the uplink and downlink communications of the UE. Thus, a UE that communicates with one or more base stations in a network can also be understood as a UE that communicates with the network.

[0059] The base station 102 and the user equipment can be configured to communicate via a transmission medium using any of various radio access technologies (RATs), which are also referred to as wireless communication technologies or telecommunications standards, such as GSM, UMTS (WCDMA), LTE, LTE-Advanced (LTE-A), LAA / LTE-U, 5G NR, 3GPP2, CDMA2000 (e.g., 1xRTT, 1xEV-DO, HRPD, eHRPD), Wi-Fi, etc.

[0060] Base stations 102 and other similar base stations operating according to the same or different cellular communication standards can thus provide one or more cell networks that can provide continuous or nearly continuous overlapping services to the UEs 106 and similar devices over a certain geographical area via one or more cellular communication standards.

[0061] Note that the UE 106 is capable of communicating using multiple wireless communication standards. For example, the UE 106 may be configured to communicate using either or both of the 3GPP cellular communication standard or the 3GPP2 cellular communication standard. In some embodiments, the UE 106 may be configured to perform techniques for determining quasi-co-location assumptions for non-periodic channel state information reference signals for multi-transmission-reception point operations in a wireless communication system, such as according to the various methods described herein. The UE 106 may also be configured or alternatively configured to communicate using WLAN, BLUETOOTH TM , one or more Global Navigation Satellite Systems (GNSS, such as GPS or GLONASS), one and / or more mobile television broadcast standards (e.g., ATSC-M / H), etc. Other combinations of wireless communication standards (including more than two wireless communication standards) are also possible.

[0062] Figure 2 An exemplary user equipment 106 (e.g., one of devices 106A to 106N) communicating with a base station 102 is shown according to some embodiments. The UE 106 may be a device having wireless network connectivity, such as a mobile phone, a handheld device, a wearable device, a computer or tablet, an unmanned aerial vehicle (UAV), an unmanned aircraft controller (UAC), an automobile, or almost any type of wireless device. The UE 106 may include a processor (processing element) configured to execute program instructions stored in a memory. The UE 106 may perform any of the method embodiments described in the present invention by executing such stored instructions. Alternatively or additionally, the UE 106 may include programmable hardware elements, such as an FPGA (Field Programmable Gate Array), an integrated circuit, and / or any one of various other possible hardware components configured to perform (e.g., individually or in combination) any one of the method embodiments described herein or any part of any one of the method embodiments described herein. The UE 106 may be configured to communicate using any one of multiple wireless communication protocols. For example, the UE 106 may be configured to communicate using two or more of CDMA2000, LTE, LTE-A, 5G NR, WLAN, or GNSS. Other combinations of wireless communication standards are also possible.

[0063] UE 106 may include one or more antennas that communicate using one or more wireless communication protocols according to one or more RAT standards. In some embodiments, UE 106 may share one or more portions of the receive chain and / or transmit chain among multiple wireless communication standards. The shared radio components may include a single antenna or may include multiple antennas for performing wireless communication (e.g., for MIMO). Generally, the radio components may include any combination of a baseband processor, analog radio frequency (RF) signal processing circuitry (e.g., including filters, mixers, oscillators, amplifiers, etc.) or digital processing circuitry (e.g., for digital modulation and other digital processing). Similarly, the radio components may implement one or more receive chains and transmit chains using the foregoing hardware.

[0064] In some embodiments, UE 106 may include separate transmit chains and / or receive chains (e.g., including separate antennas and other radio components) for each wireless communication protocol it is configured to communicate with. As another possibility, UE 106 may include one or more radio components shared among multiple wireless communication protocols and one or more radio components uniquely used by a single wireless communication protocol. For example, UE 106 may include shared radio components for communicating using any of LTE or CDMA2000 1xRTT (or LTE or NR, or LTE or GSM), and separate radio components for communicating using each of Wi-Fi and BLUETOOTH TM Each. Other configurations are possible.

[0065] Figure 3 - Block diagram of an exemplary UE device

[0066] Figure 3FIG. shows a block diagram of an exemplary UE 106 in accordance with some embodiments. As shown, UE 106 may include a system-on-a-chip (SOC) 300, which may include portions for various purposes. For example, as shown, SOC 300 may include a processor 302 that may execute program instructions for UE 106, and a display circuit 304 that may perform graphics processing and provide a display signal to a display 360. SOC 300 may also include a sensor circuit 370, which may include components for sensing or measuring any of a variety of possible characteristics or parameters of UE 106. For example, sensor circuit 370 may include a motion sensing circuit configured to detect the motion of UE 106 using, for example, a gyroscope, an accelerometer, and / or any of a variety of other motion sensing components. As another possibility, sensor circuit 370 may include one or more temperature sensing components, for example, for measuring the temperature of each of one or more antenna panels and / or other components of UE 106. As needed, any of a variety of other possible types of sensor circuits may also or alternatively be included in UE 106. Processor 302 may also be coupled to a memory management unit (MMU) 340, which may be configured to receive addresses from processor 302 and translate those addresses into locations in a memory (e.g., memory 306, read-only memory (ROM) 350, NAND flash memory 310) and / or other circuits or devices, such as display circuit 304, radio components 330, connector I / F 320, and / or display 360. MMU 340 may be configured to perform memory protection and page table translation or setup. In some embodiments, MMU 340 may be included as part of processor 302.

[0067] 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 310), a connector interface 320 (e.g., for coupling to a computer system, a docking station, a charging station, etc.), a display 360, and wireless communication circuitry 330 (e.g., for LTE, LTE-A, NR, CDMA2000, BLUETOOTH 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 communication with the base station 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. Generally speaking, one or more antennas are collectively referred to as antenna 335. For example, the UE device 106 may use antenna 335 via radio circuitry 330 to perform wireless communication. As described above, in some embodiments, the UE may be configured to perform wireless communication using multiple wireless communication standards.

[0068] The UE 106 may include hardware and software components for implementing the methods of the UE 106 to perform techniques for determining quasi-co-location assumptions for non-periodic channel state information reference signals for multi-transmission-reception point operation in a wireless communication system, such as further described hereinbelow. 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). Additionally, as Figure 3 shown, the processor 302 may be coupled to and / or interoperate with other components to perform techniques for determining quasi-co-location assumptions for non-periodic channel state information reference signals for multi-transmission-reception point operation in a wireless communication system according to various embodiments disclosed herein. The processor 302 may also implement various other applications and / or end-user applications running on the UE 106.

[0069] In some embodiments, the radio component 330 may include separate controllers dedicated to controlling communication for various respective RAT standards. For example, as Figure 3 shown, the radio component 330 may include a Wi-Fi controller 352, a cellular controller (e.g., an LTE and / or LTE-A controller) 354, and a BLUETOOTH TM controller 356, and in at least some embodiments, one or more or all of these controllers may be implemented as respective integrated circuits (simply referred to as ICs or chips), which communicate with each other and with the SOC 300 (more specifically with the processor 302). For example, the Wi-Fi controller 352 may communicate with the cellular controller 354 via a cell-ISM link or a WCI interface, and / or BLUETOOTH TMThe controller 356 may communicate with the cellular controller 354 via a cell-ISM link or the like. Although three separate controllers are shown within the radio component 330, other embodiments may be implemented in the UE device 106 with fewer or more similar controllers for various different RATs.

[0070] In addition, embodiments are contemplated in which the controller may implement functions associated with multiple radio access technologies. For example, according to some embodiments, in addition to the hardware and / or software components for performing cellular communication, the cellular controller 354 may further include hardware and / or software components for performing one or more activities associated with Wi-Fi, such as Wi-Fi preamble detection, and / or generation and transmission of Wi-Fi physical layer preamble signals.

[0071] Figure 4 - Block diagram of an exemplary base station

[0072] Figure 4 A block diagram of an exemplary base station 102 according to some embodiments is shown. Note that Figure 4 the base station is only one example of a possible base station. As shown, the base station 102 may include a processor 404 that may execute program instructions for the base station 102. The processor 404 may also be coupled to a memory management unit (MMU) 440 or other circuitry or device, which may be configured to receive addresses from the processor 404 and translate those addresses into locations in a memory (e.g., memory 460 and read-only memory (ROM) 450).

[0073] The base station 102 may include at least one network port 470. The network port 470 may be configured to couple to a telephone network and provide access to multiple devices such as the UE device 106 as described above in Figure 1 and Figure 2 . The network port 470 (or an additional network port) may also be configured or alternatively configured to couple to a cellular network, such as the core network of a cellular service provider. The core network may provide mobility-related services and / or other services to multiple 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).

[0074] Base station 102 may include at least one antenna 434 and possibly multiple antennas. One or more antennas 434 may be configured to operate as a wireless transceiver and may be further configured to communicate with UE device 106 via radio component 430. Antenna 434 communicates with radio component 430 via communication link 432. Communication link 432 may be a receive link, a transmit link, or both. Radio component 430 may be designed to communicate via various radio communication standards, including but not limited to NR, LTE, LTE-A, WCDMA, CDMA2000, etc. Processor 404 of base station 102 may be configured to implement and / or support the implementation of part or all of the methods described herein, for example, by executing program instructions stored on a memory medium (e.g., a non-transitory computer-readable memory medium). Alternatively, processor 404 may be configured as a programmable hardware element such as an FPGA (Field Programmable Gate Array), or as an ASIC (Application Specific Integrated Circuit), or a combination thereof. In the case of certain RATs (e.g., Wi-Fi), base station 102 may be designed as an access point (AP), in which case 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 radio component 430 may be designed to communicate according to the Wi-Fi standard.

[0075] Channel state information

[0076] Wireless devices such as user equipment may be configured to measure the quality of the downlink channel and report information related to the quality measurement to the base station. For example, the UE may periodically send channel state information (CSI) to the BS. The base station may then receive and use the channel state information during communication with the wireless device to determine adjustments to various parameters. Specifically, the BS may use the received channel state information to adjust the coding of its downlink transmission to improve the downlink channel quality.

[0077] In most cellular systems, the base station transmits pilot signals (or reference signals), such as channel state information reference signals (CSI-RS), where the reference signal is used to estimate the channel (or a part of the channel) between the base station and the UE. The UE receives the reference signal and calculates channel state information (CSI) based on the reference signal. Then, the UE reports the channel state information back to the base station. Then, the base station may generate downlink data based on the received CSI and transmit the downlink data to the UE. In other words, the base station may adjust the way the downlink data is encoded and generated based on the channel state information received from the UE.

[0078] For example, according to at least some embodiments, in the 3GPP NR cellular communication standard, the channel state information fed back from a UE may include one or more of a channel quality indicator (CQI), a precoding matrix indicator (PMI), a rank indicator (RI), a CSI-RS resource indicator (CRI), an SSBRI (SS / PBCH resource block indicator), and a layer indicator (LI).

[0079] The channel quality information may be provided to the base station for link adaptation, for example, to provide guidance on which modulation and coding scheme (MCS) the base station should use when transmitting data. For example, when the communication quality of the downlink channel between the base station and the UE is determined to be high, the UE may feedback a high CQI value, which may cause the base station to transmit data using a relatively high modulation order and / or a low channel coding rate. As another example, when the communication quality of the downlink channel between the base station and the UE is determined to be low, the UE may feedback a low CQI value, which may cause the base station to transmit data using a relatively low modulation order and / or a high channel coding rate.

[0080] PMI feedback may include preferred precoding matrix information and may be provided to the base station to indicate which MIMO precoding scheme the base station should use. In other words, the UE may measure the quality of the downlink MIMO channel between the base station and the UE based on the pilot signals received on the channel and may recommend which MIMO precoding the desired base station should apply through PMI feedback. In some cellular systems, the PMI configuration is represented in matrix form, which provides linear MIMO precoding. The base station and the UE may share a codebook composed of multiple precoding matrices, where each MIMO precoding matrix in the codebook may have a unique index. Therefore, as part of the channel state information fed back by the UE, the PMI may include the index (or possibly multiple indexes) corresponding to the most preferred MIMO precoding matrix (or matrices) in the codebook. This may enable the UE to minimize the amount of feedback information. Therefore, according to at least some embodiments, the PMI may indicate which precoding matrix from the codebook should be used for transmission to the UE.

[0081] For example, when the base station and the UE have multiple antennas, the rank indicator information (RI feedback) may indicate the number of transmission layers that the UE determines can be supported by the channel, which can be achieved through spatial multiplexing for multi-layer transmission. The RI and the PMI may jointly allow the base station to know which precoding needs to be applied to which layer, for example, depending on the number of transmission layers.

[0082] In some cellular systems, the PMI codebook is defined according to the number of transmission layers. In other words, for R-layer transmission, N t ×R matrices may be defined (for example, where R represents the number of layers, N trepresents the number of transmitter antenna ports, and N represents the size of the codebook). In such a scenario, the number of transmission layers (R) can conform to the rank value of the precoding matrix (N t ×R matrix), and thus R can be referred to as the "Rank Indicator (RI)" in this context.

[0083] Therefore, the channel state information can include the allocated rank (e.g., rank indicator or RI). For example, a MIMO-capable UE communicating with the BS can include four receiver chains and, for example, can include four antennas. The BS can also include four or more antennas to enable MIMO communication (e.g., 4×4 MIMO). Thus, the UE is capable of receiving up to four (or more) signals (e.g., layers) from the BS simultaneously. Layer-to-antenna mapping can be applied, for example, each layer can be mapped to any number of antenna ports (e.g., antennas). Each antenna port can transmit and / or receive information associated with one or more layers. The rank can include multiple bits and can indicate the number of signals that the BS can send to the UE during an upcoming time period (e.g., during an upcoming transmission time interval or TTI). For example, an indication of rank 4 can indicate that the BS will send 4 signals to the UE. As a possibility, the length of the RI can be two bits (e.g., since two bits are sufficient to distinguish 4 different rank values). Note that according to various embodiments, other quantities and / or configurations of antennas (e.g., at either or both of the UE or the BS) and / or other quantities of data layers are possible.

[0084] Figure 5 - QCL assumptions for aperiodic CSI-RS for multi-TRP operation

[0085] According to some cellular communication technologies, a wireless device can communicate with multiple transmission and reception points (TRPs), including potentially simultaneously. Downlink control information (DCI) can be used to schedule such communication, and this downlink control information can be provided using control signaling, such as on a physical downlink control channel (PDCCH) that can be transmitted in one or more control resource sets (CORESETs). The DCI can be provided in a single DCI mode, in which communication using a single DCI (e.g., from only one TRP) is used to schedule communication between multiple TRPs and the wireless device, or the DCI can be provided in a multi-DCI mode, in which each TRP among the multiple TRPs can provide DCI communication to schedule its own communication with the wireless device.

[0086] Communications scheduled in such multi-TRP scenarios can include data communications (e.g., which can be transmitted using the Physical Downlink Shared Channel (PDSCH)) and / or aperiodic Channel State Information Reference Signal (CSI-RS) transmissions, among other possibilities. Additionally, aperiodic CSI-RS transmissions can include CSI-RS configured for multiple possible purposes such as for beam management, tracking, or CSI acquisition. At least according to some embodiments, the amount of time between a DCI transmission and the communication scheduled by the DCI (e.g., in any of various absolute units or units specific to a cellular communication system, such as milliseconds, time slots, symbols, etc.) can be referred to as the scheduling offset.

[0087] When a wireless device receives a DCI scheduling (e.g., PDSCH or aperiodic CSI-RS) communication, the wireless device may require a certain amount of time to decode the DCI and determine the scheduling time of the communication. At least in some embodiments, this amount of time can be referred to as the scheduling offset threshold and can be reported by the wireless device in the capability information. If the DCI schedules the communication with a scheduling offset greater than the scheduling offset threshold, the wireless device can fully decode and determine the resources scheduled for the communication, which may include, for example, the beam configuration to be used for the communication. For example, at least in some embodiments, the DCI can include a quasi-co-location indication such as a Transmission Configuration Indicator (TCI), from which the wireless device can select an antenna / beam configuration to receive the signal scheduled by the DCI. However, if the DCI schedules the communication with a scheduling offset lower than the scheduling offset threshold, the wireless device may not be able to determine the TCI used for the communication from the DCI before the communication occurs. In some instances, it may be possible to require that the scheduling offset (e.g., at least for certain types of communications) is always greater than the wireless device's scheduling offset threshold, however at least in some instances, this can limit network scheduling flexibility.

[0088] Thus, at least in some embodiments, in a case where a scheduling offset of a DCI transmission is lower than a scheduling offset threshold of a wireless device, the wireless device may use a quasi - co - location assumption to buffer the received signal. The quasi - co - location assumption may include assumptions about: if the DCI schedules a communication with a scheduling offset lower than the scheduling offset threshold of the wireless device, the antenna and beam configurations to be used (e.g., TCI state). In other words, the wireless device may make a quasi - co - location assumption in order to determine the spatial filter (e.g., which antenna ports / beam configurations) to apply to or command for: receiving and buffering a signal that may contain the scheduled communication in the absence of an explicit quasi - co - location indication (e.g., before possible decoding). In such cases, if the DCI transmission does schedule the communication included in the buffered signal, the wireless device is able to decode the transmission from the buffered signal after decoding the DCI. At least according to some embodiments, if both the wireless device and the network know the technique by which the wireless device determines the quasi - co - location assumption, such a mechanism may allow a cellular network to schedule a communication with a scheduling offset lower than the scheduling offset threshold of the wireless device and expect the wireless device to be able to reliably receive and decode the scheduled communication, e.g., if those communications are scheduled according to the quasi - co - location assumption that the wireless device will make.

[0089] Thus, it may be beneficial to specify a technique for a wireless device to determine a quasi - co - location assumption in various scenarios. To illustrate a set of such possible techniques, Figure 5 is a flowchart showing a method for determining a quasi - co - location assumption for an aperiodic channel state information reference signal for multi - transmission - reception point operation in a wireless communication system according to at least some embodiments.

[0090] Figure 5 Aspects of the method may be implemented by a wireless device, e.g., in conjunction with one or more cellular base stations (such as UE 106 and BS 102 shown and described with respect to the various figures herein), or more generally, in conjunction with any of the computer circuits, systems, devices, elements, or components shown in the above - mentioned figures as needed. For example, a processor (and / or other hardware) of such a device may be configured to cause the device to perform any combination of the shown method elements and / or other method elements.

[0091] Note that although aspects of the method are described in a way that involves communication technologies and / or features associated with 3GPP and / or NR specification documents, this description is not intended to limit the present disclosure, and it may be used in any suitable wireless communication system as needed. Figure 5 Figure 5 ​Aspects of the method. In various embodiments, some of the elements of the illustrated method may be executed simultaneously in an order different from the illustrated order, may be replaced by other method elements, or may be omitted. Additional method elements may also be performed as needed. As shown, Figure 5 the method may operate as follows.

[0092] The wireless device may establish a wireless link with a cellular base station. According to some embodiments, the wireless link may include a cellular link according to 5G NR. For example, the wireless device may establish a session with an AMF entity of the cellular network via one or more gNBs that provide radio access to the cellular network. As another possibility, the wireless link may include a cellular link according to LTE. For example, the wireless device may establish a session with a mobility management entity of the cellular network via an eNB that provides radio access to the cellular network. According to various embodiments, other types of cellular links are also possible, and the cellular network may also or alternatively operate according to another cellular communication technology (e.g., UMTS, CDMA2000, GSM, etc.).

[0093] Establishing the wireless link may include establishing an RRC connection with the serving cellular base station at least according to some embodiments. Establishing the first RRC connection may include configuring various parameters for communication between the wireless device and the cellular base station, establishing environmental information of the wireless device, and / or any of various other possible features, e.g., relating to establishing an air interface of the wireless device for cellular communication with the cellular network associated with the cellular base station. After establishing the RRC connection, the wireless device may operate in the RRC connected state. In some instances, the RRC connection may also be released (e.g., after a certain period of inactivity with respect to data communication), in which case the wireless device may operate in the RRC idle state or the RRC inactive state. In some instances, e.g., due to wireless device mobility, change in wireless medium conditions, and / or any of various other possible reasons, the wireless device may perform a handover (e.g., when in the RRC connected mode) or cell reselection (e.g., when in the RRC idle mode or the RRC inactive mode) to a new serving cell.

[0094] At least according to some embodiments, the wireless device may establish multiple wireless links with multiple TRPs of the cellular network, for example, according to a multi-TRP configuration. In such scenarios, the wireless device may be configured (e.g., via RRC signaling) to have one or more transmission control indicators (TCIs), e.g., the one or more TCIs may correspond to various beams that can be used for communication with the TRP. Additionally, there may be a situation where one or more of the configured TCI states can be activated by a media access control (MAC) control element (CE) of the wireless device at a particular time.

[0095] In at least some instances, establishing a wireless link may include a wireless device providing information about the capabilities of the wireless device. Such capability information may include information related to any one of a variety of types of wireless device capabilities. As one such possibility, the capability information may indicate one or more aperiodic CSI-RS QCL assumption determination methods supported by the wireless device. For example, some or all of the architectures described herein with reference to Figure 5 an architecture for determining QCL assumptions for aperiodic CSI-RS or another architecture for determining QCL assumptions for aperiodic CSI-RS may be defined as a feature that a wireless device may indicate support or non-support for.

[0096] At 502, the wireless device may receive downlink control information. According to various embodiments, the downlink control information may be received in a single DCI mode or a multi-DCI mode. The DCI may be provided using scheduled PDCCH communication via one or more CORESETs configured for the wireless device to monitor. In some instances, in the single DCI mode, the DCI may be provided using scheduled PDCCH communication via a single CORESET, while in the multi-DCI mode, it may be possible to provide the DCI using one (or more) of the multiple CORESETs configured for the wireless device to monitor (e.g., received using different TCIs).

[0097] At 504, the wireless device may determine the QCL assumption for the aperiodic CSI-RS for the downlink control information. The QCL assumption determination method may be at least partially based on whether the DCI is received in a single DCI mode or a multi-DCI mode, and / or at least partially based on the type of CSI-RS for which the QCL assumption is determined (e.g., CSI-RS for beam management; CSI-RS for tracking; or CSI-RS for CSI acquisition).

[0098] For example, as one possibility, if the DCI is received in the single DCI mode, determining the QCL assumption for the aperiodic CSI-RS for the downlink control information may include: selecting the TCI corresponding to the lowest TCI code point in the active TCI code point including two different TCI states. In such a scenario, if there is no TCI code point including more than 1 TCI state (or possibly, if the wireless device indicates in the capability information that it does not support such a method for determining the QCL assumption for aperiodic CSI-RS), the QCL assumption may be based on the QCL assumption for the monitored control resource set with the lowest identifier in the latest time slot.

[0099] As another possibility, if DCI is received in single DCI mode, determining the QCL assumption for aperiodic CSI-RS for downlink control information may include: selecting one of the TCIs included in the lowest TCI code point among the active TCI code points including two different TCI states (e.g., one of the two TCIs). Which of the two TCIs to select can be determined in any of various ways and can be pre-configured or can be configured by the cellular network (e.g., using configuration information received from the serving base station). As one possibility, which of the two TCIs to select can be based on the order of the two different TCI states included in the lowest TCI code point among the active TCI code points including two different TCI states (e.g., the first TCI can be selected, or the second TCI can be selected). As another possibility, which of the two TCIs to select can be based on their TCI state identifiers (e.g., the TCI with the lower TCI state ID can be selected, or the TCI with the higher TCI state ID can be selected). As yet another possibility, which of the two TCIs to select can be based on the CSI-RS resource index or CSI-RS resource set index of the aperiodic CSI-RS (e.g., the TCI state with TCI index = CSI-RS resource set index mod 2 can be selected, or any of various other formulas that associate the CSI-RS resource index or CSI-RS resource set index with the TCI index can be used to select the TCI). In such scenarios, if there is no TCI code point including more than 1 TCI state (or possibly, if the wireless device indicates in its capability information that it does not support such a method for determining the QCL assumption for aperiodic CSI-RS), the QCL assumption can be based on the QCL assumption for the monitoring control resource set with the lowest identifier in the latest time slot.

[0100] In some instances, if DCI is received in single DCI mode, but there is no TCI state activated by a MAC CE, the wireless device can determine the QCL assumption for aperiodic CSI-RS based on the QCL assumption for the CORESET with the lowest identifier in the latest time slot, or if there is no configured CORESET, the wireless device can determine the QCL assumption for aperiodic CSI-RS based on the TCI state with the lowest identifier and activated by RRC signaling. Alternatively, if DCI is received in single DCI mode, but there is no TCI state activated by a MAC CE, the wireless device can determine the QCL assumption for aperiodic CSI-RS based on the synchronization signal block (SSB) identified during the initial access procedure or the most recent random access procedure.

[0101] As yet another possibility, if DCI is received in a multi-DCI mode, determining the QCL assumption for the aperiodic CSI-RS for each corresponding CORESET pool (e.g., each of the multiple CORESET pools) may include: determining the QCL assumption for the aperiodic CSI-RS based on the QCL assumption for the CORESET with the lowest identifier in the latest time slot among the CORESETs in the corresponding CORESET pool. In such a scenario, if the wireless device indicates in the capability information that it does not support such a method for determining the QCL assumption for the aperiodic CSI-RS, there may be a case where the default QCL assumption is based on the QCL assumption of the monitored CORESET with the lowest identifier in the latest time slot.

[0102] As yet another possibility, if DCI is received in a multi-DCI mode, determining the QCL assumption for the aperiodic CSI-RS for the corresponding CORESET may be based on: the QCL assumption for the CORESET with the lowest identifier in the latest time slot among the CORESETs in the same CORESET pool as the corresponding CORESET. In such a scenario, if the wireless device indicates in the capability information that it does not support such a method for determining the QCL assumption for the aperiodic CSI-RS, there may be a case where the default QCL assumption is based on the QCL assumption of the monitored CORESET with the lowest identifier in the latest time slot.

[0103] In some instances, if there is no configured CORESET in the multi-DCI mode, determining the QCL assumption for the aperiodic CSI-RS may include: selecting the TCI state with the lowest identifier and activated by the MAC CE. If there is no TCI state activated by the MAC CE, the QCL assumption may be determined based on the SSB in the same component carrier or in the component carrier with the lowest identifier in the same frequency band or frequency band group.

[0104] In 506, if the scheduling offset of the downlink control information is lower than the scheduling offset threshold, the wireless device may buffer the received signal according to the determined QCL assumption for the aperiodic CSI-RS. Thus, at least according to some embodiments, if the DCI indicates that the aperiodic CSI is scheduled using the determined QCL assumption with a scheduling offset lower than the scheduling offset threshold, the wireless device can extract the aperiodic CSI scheduled by the DCI from the buffered signal.

[0105] Note that it may be negotiated that, at least in some instances, the scheduling offset for the aperiodic CSI-RS will be no less than a scheduling offset threshold reported by the wireless device. In such scenarios, the wireless device may not determine the QCL assumption for the aperiodic CSI-RS for the DCI, or buffer the received signal for the aperiodic CSI-RS. Such negotiation may be always valid, or may be configured at a specific time and / or for a specific scenario. For example, such negotiation may apply a single DCI mode and / or multiple DCI modes, and / or apply to any or all of the CSI-RS for beam management, the CSI-RS for tracking, or the CSI-RS for CSI acquisition. Note also that even in such scenarios, at least according to some embodiments, there may be a situation where the wireless device may still determine the QCL assumption for the PDSCH for the DCI, and buffer the received signal for the PDSCH based on the determined QCL assumption for the PDSCH.

[0106] Thus, at least according to some embodiments, Figure 5 The method can be used to provide a unified framework according to which a wireless device can determine a QCL hypothesis for an aperiodic CSI-RS, and therefore according to which a cellular network can schedule an aperiodic CSI-RS with a scheduling offset below a scheduling offset threshold of the wireless device. Therefore, in at least some instances, such an architecture can help improve cellular network scheduling flexibility and improve overall network efficiency.

[0107] Figures 6 to 11 and additional information

[0108] Figures 6 to 11 Shown can be combined if necessary Figure 5 However, it should be noted that Figures 6 to 11 The exemplary details shown in and described with respect to these figures are not intended to limit the disclosure as a whole: many variations and alternatives to the details provided below are possible and are to be considered within the scope of the disclosure.

[0109] For multi-TRP operation, PDSCH may be transmitted from multiple TRPs based on different transmission configuration indicators (TCIs). According to at least some embodiments, TCI may be used to indicate a quasi co-location (QCL) assumption for PDSCH reception, e.g., as defined in 3GPP TS 38.214, version 15.8.0, section 5.1.5. There may be cases where PDSCH may be scheduled via a single downlink control information (DCI) transmission or via multiple DCI transmissions, e.g., in single DCI mode or in multiple DCI mode.

[0110] If the scheduling offset for the PDSCH is below a certain threshold, there may be a situation where the UE does not have enough time to decode the scheduling PDCCH for a potential PDSCH transmission. In this case, the UE can apply the default QCL, for example, to buffer the received signal in the case where a PDSCH transmission is indeed scheduled.

[0111] As a possibility, it can be negotiated that the default QCL assumption for the single DCI mode can be based on: two TCI states corresponding to the lowest TCI code point among the TCI code points that include two different activated TCI states. It can also be negotiated that the default QCL assumption for the multi DCI mode can be based on: the QCL assumption for the monitoring control resource set (CORESET) with the lowest ID in the latest time slot among the CORESETs with the same CORESET - poolIndex.

[0112] Figure 6 An example of a possible method for determining the default PDSCH QCL assumption for the single DCI mode according to some embodiments is shown. The TCI code point can correspond to the TCI field indicated by the DCI. As shown, in the exemplary scenario, the TCI code points indicating TCI 3 and TCI 4 can be the lowest TCI code points among the TCI code points that include two different activated TCI states, and thus can be used as the default PDSCH QCL assumption. Note that alternatively, for example, if the UE does not support this feature, the UE can fallback to the previous version of the PDSCH QCL assumption, such as the PDSCH QCL assumption in 3GPP Release 15. At least according to some embodiments, this can include: if multiple CORESETs are configured, selecting the default PDSCH QCL based on the QCL assumption for the CORESET with the lowest ID in the latest time slot. If no CORESET is configured, the default PDSCH QCL can be based on the activated TCI state with the lowest ID.

[0113] Figure 7Shows an example of a possible method for determining the default PDSCH QCL assumption for multi-DCI modes. According to the shown method, the UE can search for the most recently monitored CORESET for each CORESET pool, and if there are multiple CORESETS for a given CORESET pool in the most recent time slot, the one with the lowest CORESET ID can be selected. Thus, as shown, in the exemplary scenario, TCI 3 and TCI 4 can be used as the default PDSCH QCL assumptions; TCI 3 can be selected as the monitored CORESET with the lowest ID among the CORESETS with CORESET-poolIndex = 0 and in the most recent time slot, while TCI 4 can be selected as the monitored CORESET with the lowest ID among the CORESETS with CORESET-poolIndex = 1 and in the most recent time slot. Note that alternatively, for example, if the UE does not support this feature, the UE can fallback to the previous version of the PDSCH QCL assumption, such as the PDSCH QCL assumption of 3GPP Release 15. At least according to some embodiments, this may include: if multiple CORESETS are configured, selecting the default PDSCH QCL based on the QCL assumption for the CORESET with the lowest ID in the most recent time slot. If no CORESET is configured, the default PDSCH QCL can be based on the active TCI state with the lowest ID.

[0114] At least according to some embodiments, considering the following possibility, it may also be useful to provide techniques for determining the default QCL assumption for aperiodic CSI-RS: scheduling aperiodic CSI-RS by DCI with a scheduling offset lower than the threshold that allows the UE to decode DCI. For example, it may be useful to specify the QCL assumption for each of: single DCI mode and multi-DCI mode; and CSI-RS for beam management (e.g., CSI-RS resources in a resource set with configured repetition parameters), CSI-RS for tracking (e.g., CSI-RS resources in a resource set with configured TRS-info parameters), CSI-RS for CSI acquisition (e.g., CSI-RS resources in a resource set without configured repetition or TRS-info parameters). Note that at least according to some embodiments, there may be cases where it is not allowed to configure repetition and TRS-info in a CSI-RS resource set.

[0115] If the scheduling offset in single DCI mode is below a certain threshold, then as an option for determining the aperiodic CSI-RS QCL assumption, the QCL for aperiodic CSI-RS can be based on the TCI state corresponding to the lowest TCI code point among the TCI code points that include two different TCI states activated by the medium access control (MAC) control element (CE). If there is no TCI code point mapped to more than 1 TCI state, or if the UE does not support this feature, then if multiple CORESETs are configured, the aperiodic CSI-RS CQL can be based on: the QCL assumption for the monitored CORESET with the lowest ID in the latest slot.

[0116] Figure 8 Examples of such possible methods for determining the default aperiodic CSI-RS QCL assumption for single DCI mode according to some embodiments are shown. As shown, in an exemplary scenario, the TCI code points indicating TCI 3 and TCI 4 can be the lowest TCI code points among the TCI code points that include two different activated TCI states, and thus can be used as the default aperiodic CSI-RS QCL assumption. In a scenario where the UE does not support this feature, the UE can select TCI 3 as the default aperiodic CSI QCL assumption, for example, based on the QCL assumption for the CORESET with the lowest ID in the latest slot being TCI 3.

[0117] If the scheduling offset in the single DCI mode is below a certain threshold, then as another option for determining the aperiodic CSI-RS QCL assumption, the QCL for the aperiodic CSI-RS can be based on one of the TCI states, where these TCI states correspond to the lowest TCI code point among the TCI code points that include two different TCI states activated by the MAC CE. If there is no TCI code point mapped to more than 1 TCI state, or if the UE does not support this feature, then if multiple CORESETs are configured, the default aperiodic CSI-RS QCL assumption can be based on: the QCL assumption for the monitoring CORESET with the lowest ID in the latest time slot. The TCI state selection (selecting one from two TCI states) can be based on one of the following options. As the first option, the UE always selects the TCI state based on the order of the TCI states (e.g., always selects the first TCI state, or always selects the second TCI state). As the second option, the UE always selects the TCI state based on the ID of the TCI state (e.g., always selects the TCI state with the lowest ID, or always selects the TCI state with the highest ID). As the third option, the TCI index to be selected is configured by higher layer signaling from the cellular base station (e.g., gNB). As the fourth option, the TCI index to be selected is determined by the CSI-RS resource index or the CSI-RS resource set index. For example, as a possibility, the following formula can be used:

[0118] TCI index = CSI-RS resource set index mod 2

[0119] to determine the TCI index to be selected.

[0120] Figure 9 An example of such a possible method for determining the default aperiodic CSI-RS QCL assumption for the single DCI mode according to some embodiments is shown. As shown, in the exemplary scenario, the TCI code points indicating TCI 3 and TCI 4 can be the lowest TCI code points among the TCI code points that include two different activated TCI states, and from these TCI states, TCI 3 can be selected as the default aperiodic CSI-RS QCL assumption. In a scenario where the UE does not support this feature, the UE can select TCI 5 as the default aperiodic CSI QCL assumption, for example, based on the QCL assumption for the CORESET with the lowest ID in the latest time slot being TCI 5.

[0121] Note that, as another possibility, it can be negotiated that for single DCI mode, the scheduling offset for aperiodic CSI-RS should always be no less than the reported scheduling offset threshold. Also note that the same or different options can be applied to different types of CSI-RS (e.g., CSI-RS for beam management, CSI-RS for tracking, and CSI-RS for CSI acquisition). If there is no TCI state activated by a MAC CE, the default CQL for aperiodic CSI-RS and PDSCH can be based on one of the following options. As a first option, when the scheduling offset is lower than the scheduling offset threshold, if multiple CORESETs are configured, the PDSCH / aperiodic CSI-RS CQL assumption is based on the QCL assumption for the CORESET with the lowest ID in the latest time slot; if no CORESET is configured, the default PDSCH / aperiodic CSI-RS CQL assumption can be based on the TCI state with the lowest ID (e.g., activated by RRC). As a second option, when the scheduling offset is lower than the scheduling offset threshold, the PDSCH / aperiodic CSI-RS CQL assumption is based on the synchronization signal block identified during the initial access procedure or the most recent random access procedure.

[0122] If the scheduling offset is lower than a certain threshold in multi-DCI mode, then as an option for determining the aperiodic CSI-RS QCL assumption, the QCL for aperiodic CSI-RS can be based on: the QCL assumption for the monitored CORESET with the lowest ID in the latest time slot among the CORESETs with the same CORESET pool index. If the UE does not support this feature, then if multiple CORESETs are configured, the default aperiodic CSI-RS CQL can be based on: the QCL assumption for the monitored CORESET with the lowest ID in the latest time slot.

[0123] Figure 10An example of such a possible method for determining default aperiodic CSI-RS QCL assumptions for multi-DCI modes is shown. As shown, in an exemplary scenario, TCI 3 can be the QCL for the only CORESET (CORESET 1) with CORESET-poolIndex = 0, and TCI 4 can be the QCL for the CORESET with the lowest ID among the CORESETs with CORESET-poolIndex = 1 (CORESET 2), so TCI 3 and TCI 4 can be used as default aperiodic CSI-RS QCL assumptions. In scenarios where the UE does not support this feature, the UE can select TCI 3 as the default aperiodic CSI QCL assumption, for example, based on the QCL assumption for the CORESET with the lowest ID in the latest time slot being TCI 3.

[0124] If the scheduling offset in the multi-DCI mode is below a certain threshold, then as another option for determining the aperiodic CSI-RS QCL assumption, the QCL for the aperiodic CSI-RS can be based on: among the CORESETs with the same CORESET-poolIndex as the CORESET carrying the scheduled PDCCH, the QCL assumption for the monitored CORESET with the lowest ID in the latest time slot. If the UE does not support this feature, then if multiple CORESETs are configured, the default aperiodic CSI-RS CQL can be based on: the QCL assumption for the monitored CORESET with the lowest ID in the latest time slot.

[0125] Figure 11 An example of such a possible method for determining default aperiodic CSI-RS QCL assumptions for multi-DCI modes is shown. As shown, in an exemplary scenario, for the CSI-RS scheduled by CORESET 1, the default QCL for the aperiodic CSI-RS can be based on TCI 3, for example, because TCI 3 is the QCL for CORESET 1, and CORESET 1 is the only monitored CORESET with CORESET-poolIndex = 0 and in the latest time slot. Similarly, for the CSI-RS scheduled by CORESET 2 or 3, the default QCL for the aperiodic CSI-RS can be based on TCI 4, for example, because TCI 4 is the QCL for CORESET 2, which can be the CORESET with the lowest ID among the CORESETs with CORESET-poolIndex = 1.

[0126] Note that, as yet another possibility, it may be negotiated that for multi-DCI mode, the scheduling offset for aperiodic CSI-RS should always be no less than the reported scheduling offset threshold. Also note that the same or different options may be applied to different types of CSI-RS (e.g., CSI-RS for beam management, CSI-RS for tracking, and CSI-RS for CSI acquisition). According to some embodiments, if there is no configured CORESET, the default QCL may follow the QCL of the TCI state that is activated by a MAC CE and has the lowest ID. According to some embodiments, if there is no activated TCI state, the default QCL may follow the SSB in the same component carrier (CC) or in the CC with the lowest ID in the same frequency band or frequency band group.

[0127] In the following, additional exemplary embodiments are provided.

[0128] A set of embodiments may include an apparatus that includes: a processor configured to cause a wireless device to: receive downlink control information (DCI); determine a quasi-colocation (QCL) assumption for an aperiodic channel state information reference signal (CSI-RS) for the downlink control information; and buffer the received signal according to the QCL assumption for the aperiodic CSI-RS if the scheduling offset of the DCI is below a scheduling offset threshold.

[0129] According to some embodiments, the DCI is received in single-DCI mode, wherein to determine the QCL assumption, the processor is further configured to cause the wireless device to: select a TCI corresponding to the lowest TCI code point among the active TCI code points including two different transmission configuration indicator (TCI) states.

[0130] According to some embodiments, if there is no TCI code point including more than 1 TCI state, the determined QCL assumption for the aperiodic CSI-RS is based on: the QCL assumption for the monitoring control resource set with the lowest identifier in the latest time slot.

[0131] According to some embodiments, the DCI is received in single-DCI mode, wherein to determine the QCL assumption, the processor is further configured to cause the wireless device to: select the TCI included in the lowest TCI code point among the active TCI code points including two different transmission configuration indicator (TCI) states.

[0132] According to some embodiments, the TCI is also selected at least in part based on one or more of the following: the order of two different TCI states included in the lowest TCI code point among the active TCI code points including two different TCI states; the TCI state identifier of the TCI; the configuration information received from the cellular base station; or the CSI-RS resource index of the aperiodic CSI-RS or a CSI-RS resource set index.

[0133] According to some embodiments, if at least one transmission configuration indicator (TCI) is activated by a media access control (MAC) control element (CE), the determined quasi-co-location (QCL) assumption for the aperiodic CSI-RS includes the TCI state activated by the MAC CE, wherein if there is no TCI state activated by the media access control (MAC) control element (CE), the processor is further configured to cause the wireless device to: determine the QCL assumption for the aperiodic CSI-RS based on the QCL assumption for the control resource set with the lowest identifier in the most recent time slot; and if there is no configured control resource set, determine the QCL assumption for the aperiodic CSI-RS based on the TCI state with the lowest identifier and activated by radio resource control (RRC) signaling.

[0134] According to some embodiments, if at least one transmission configuration indicator (TCI) is activated by a media access control (MAC) control element (CE), the determined quasi-co-location (QCL) assumption for the aperiodic CSI-RS includes the TCI state activated by the MAC CE, wherein if there is no TCI state activated by the media access control (MAC) control element (CE), the processor is further configured to cause the wireless device to: determine the QCL assumption for the aperiodic CSI-RS based on the synchronization signal block (SSB) identified during the initial access procedure or the most recent random access procedure.

[0135] Another set of embodiments may include a wireless device comprising: an antenna; radio components operatively coupled to the antenna; and a processor operatively coupled to the radio components; wherein the wireless device is configured to: receive downlink control information (DCI); determine a quasi-co-location (QCL) assumption for an aperiodic channel state information reference signal (CSI-RS) for the downlink control information; and buffer the received signal according to the QCL assumption for the aperiodic CSI-RS if the scheduling offset of the DCI is lower than a scheduling offset threshold.

[0136] According to some embodiments, DCI is received in a multi-DCI mode, wherein the wireless device is further configured for each respective control resource set (CORESET) pool among a plurality of CORESET pools: to determine a QCL assumption for an aperiodic CSI-RS based on a QCL assumption for the CORESET with the lowest identifier in the latest time slot among the CORESETs in the respective CORESET pool.

[0137] According to some embodiments, DCI is received in a multi-DCI mode, wherein the wireless device is further configured to: determine a QCL assumption for an aperiodic CSI-RS for the respective CORESET based on a QCL assumption for the CORESET with the lowest identifier in the latest time slot among the CORESETs in the CORESET pool that is the same as the respective control resource set (CORESET).

[0138] According to some embodiments, DCI is received in a multi-DCI mode, wherein if there is no configured control resource set (CORESET), then for determining the QCL assumption, the processor is further configured to cause the wireless device to: select a transmission configuration indicator (TCI) state with the lowest identifier and activated by a media access control (MAC) control element (CE).

[0139] According to some embodiments, if there is no TCI state activated by a MAC CE, the wireless device is further configured to: determine a QCL assumption for an aperiodic CSI-RS based on a synchronization signal block (SSB) in the same component carrier or in a component carrier with the lowest identifier in the same frequency band or frequency band group.

[0140] According to some embodiments, the wireless device is further configured to: determine a QCL assumption for an aperiodic CSI-RS based at least in part on the type of CSI-RS for which the QCL assumption is determined.

[0141] Another set of embodiments may include a method, comprising: by a wireless device: establishing a wireless link with a plurality of transmission-reception points (TRPs) of a cellular network according to a multi-TRP configuration; receiving downlink control information (DCI); determining a quasi-colocation (QCL) assumption for an aperiodic channel state information reference signal (CSI-RS) for the downlink control information; and buffering the received signal according to the QCL assumption for the aperiodic CSI-RS if a scheduling offset of the DCI is lower than a scheduling offset threshold.

[0142] According to some embodiments, DCI is received in a single-DCI mode, wherein determining the QCL assumption further comprises: selecting a TCI corresponding to the lowest TCI code point among the active TCI code points including two different transmission configuration indicator (TCI) states.

[0143] According to some embodiments, DCI is received in a single DCI mode, wherein determining the QCL assumption further includes: selecting one of two TCIs included in the lowest TCI code point among the active TCI code points including two different transmission configuration indicator (TCI) states.

[0144] According to some embodiments, DCI is received in a multi-DCI mode, wherein the method further includes, for each respective control resource set (CORESET) pool among a plurality of CORESET pools: determining a QCL assumption for an aperiodic CSI-RS based on the QCL assumption for the CORESET with the lowest identifier in the latest time slot among the CORESETs in the respective CORESET pool.

[0145] According to some embodiments, DCI is received in a multi-DCI mode, wherein the wireless device is further configured to: determine a QCL assumption for an aperiodic CSI-RS for a given CORESET based on the QCL assumption for the CORESET with the lowest identifier in the latest time slot among the CORESETs in the same CORESET pool as the control resource set (CORESET).

[0146] According to some embodiments, DCI is received in a multi-DCI mode, wherein the method further includes: determining a QCL assumption for an aperiodic CSI-RS for each respective CORESET based on the QCL assumption for the CORESET with the lowest identifier in the latest time slot among the CORESETs in the same CORESET pool as the respective control resource set (CORESET).

[0147] According to some embodiments, the method further includes: determining the QCL assumption for the aperiodic CSI-RS is at least partially based on whether the aperiodic CSI-RS includes: CSI-RS for beam management; CSI-RS for tracking; or CSI-RS for CSI acquisition.

[0148] According to some embodiments, the method further includes: providing capability information of the wireless device to the cellular base station, wherein the capability information indicates the method for determining the aperiodic CSI-RS QCL assumption supported by the wireless device.

[0149] Another exemplary embodiment may include a method that includes: performing any or all parts of the foregoing examples by a wireless device.

[0150] Another exemplary embodiment may include an apparatus that includes: an antenna; radio components coupled to the antenna; and a processing element operatively coupled to the radio components, wherein the apparatus is configured to implement any or all parts of the foregoing examples.

[0151] Another set of exemplary embodiments may include a non-transitory computer-accessible memory medium that includes program instructions that, when executed at an apparatus, cause the apparatus to implement any or all parts of any one of the foregoing examples.

[0152] Another set of exemplary embodiments may include a computer program that includes instructions for performing any or all parts of any one of the foregoing examples.

[0153] Another set of exemplary embodiments may include an apparatus that includes means for performing any or all elements of any one of the foregoing examples.

[0154] Another set of exemplary embodiments may include an apparatus that includes a processing element configured to cause a wireless device to perform any or all elements of any one of the foregoing examples.

[0155] It is well known that the use of personally identifiable information should follow 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 inadvertent or unauthorized access or use, and the nature of authorized use should be clearly explained to users.

[0156] Any method among the methods for operating a UE described herein can form the basis for a corresponding method for operating a base station by interpreting each message / signal X received by the user equipment (UE) in the downlink as a message / signal X transmitted by the base station, and interpreting each message / signal Y transmitted by the UE in the uplink as a message / signal Y received by the base station.

[0157] The embodiments of the present disclosure can be implemented in any of a variety of forms. For example, in some embodiments, the subject matter can be implemented as a computer-implemented method, a computer-readable memory medium, or a computer system. In other embodiments, the subject matter can be implemented using one or more custom-designed hardware devices such as an ASIC. In other embodiments, the subject matter can be implemented using one or more programmable hardware elements such as an FPGA.

[0158] In some embodiments, a non-transitory computer-readable memory medium (e.g., a non-transitory memory element) may be configured to store program instructions and / or data, where if the program instructions are executed by a computer system, the computer system is caused to execute a method, such as any of the method embodiments described herein, or any combination of the method embodiments described herein, or any subset of any of the method embodiments described herein, or any combination of such subsets.

[0159] In some embodiments, a device (e.g., a UE) may be configured to include a processor (or a set of processors) and a memory medium (or a memory element), where the memory medium stores program instructions, where the processor is configured to read and execute the program instructions from the memory medium, where the program instructions are executable to implement any one of the various method embodiments described herein (or any combination of the method embodiments described herein, or any subset of any of the method embodiments described herein or any combination of such subsets). The device may be implemented in any of a variety of forms.

[0160] Although the above embodiments have been described in considerable detail, many variations and modifications will become apparent to those skilled in the art once the above disclosure is fully understood. The present disclosure is intended that the following claims be construed to cover all such variations and modifications.

Claims

1. A device for wireless communication, comprising: A processor configured to cause a wireless device to: Receive downlink control information DCI in a single DCI mode; Determine a first quasi - co - location QCL assumption for an aperiodic channel state information reference signal CSI - RS for the DCI by selecting the TCI included in the lowest TCI code point among the active TCI code points including two different transmission configuration indicator TCI states, wherein the TCI is selected based on a first TCI among the two different TCI states; and If the scheduling offset of the DCI is lower than a scheduling offset threshold, buffer the received signal according to the first QCL assumption for the aperiodic CSI - RS.

2. The device according to claim 1, Wherein the TCI is also selected at least in part based on one or more of the following: The TCI state identifier of the TCI; Configuration information received from a cellular base station; or The CSI - RS resource index or CSI - RS resource set index of the aperiodic CSI - RS.

3. A wireless device, comprising: An antenna; Radio components operatively coupled to the antenna; And A processor operatively coupled to the radio components; Wherein the wireless device is configured to: Receive downlink control information DCI in a single DCI mode; Determine a first quasi - co - location QCL assumption for an aperiodic channel state information reference signal CSI - RS for the DCI by selecting the TCI included in the lowest TCI code point among the active TCI code points including two different transmission configuration indicator TCI states, wherein the TCI is selected based on a first TCI among the two different TCI states; and If the scheduling offset of the DCI is lower than a scheduling offset threshold, buffer the received signal according to the first QCL assumption for the aperiodic CSI - RS.

4. The wireless device according to claim 3, wherein a second DCI is received in a multi - DCI mode, and wherein the wireless device is further configured for each respective control resource set CORESET pool among a plurality of control resource set CORESET pools: Determine a second QCL assumption for the aperiodic CSI - RS based on the QCL assumption for the CORESET with the lowest identifier in the latest time slot among the CORESETs in the respective CORESET pool.

5. The wireless device according to claim 3, wherein a second DCI is received in a multi - DCI mode, and wherein the wireless device is further configured to: Determine a second QCL assumption for the aperiodic CSI - RS based on the QCL assumption for the monitoring CORESET with the lowest identifier in the latest time slot among the CORESETs in the CORESET pool that is the same as the CORESET carrying the scheduling physical downlink control channel PDCCH.

6. The wireless device according to claim 3, Wherein a second DCI is received in a multi - DCI mode, Wherein if there is no configured control resource set (CORESET), in order to determine the second QCL assumption, the processor is further configured to cause the wireless device to: Select a second Transmission Configuration Indicator (TCI) state that has the lowest identifier and is activated by a Medium Access Control (MAC) Control Element (CE).

7. The wireless device according to claim 6, wherein if there is no TCI state activated by a MAC CE, the wireless device is further configured to: Determine the second QCL assumption for the aperiodic Channel State Information - Reference Signal (CSI-RS) based on a Synchronization Signal Block (SSB) in the same component carrier or in a component carrier with the lowest identifier in the same frequency band or frequency band group.

8. The wireless device according to claim 3, wherein the wireless device is further configured to: Determine the first QCL assumption for the aperiodic CSI-RS, at least in part, further based on the type of CSI-RS for which the first QCL assumption is determined.

9. A method for wireless communication, comprising: Receiving downlink control information (DCI) in a single DCI mode; Determining a first Quasi-Co-Location (QCL) assumption for an aperiodic Channel State Information - Reference Signal (CSI-RS) for the DCI by selecting a TCI included in the lowest TCI code point among active TCI code points including two different Transmission Configuration Indicator (TCI) states, wherein the TCI is selected based on a first TCI among the two different TCI states; and Buffering the received signal according to the first QCL assumption for the aperiodic CSI-RS if a scheduling offset of the DCI is lower than a scheduling offset threshold.

10. The method according to claim 9, further comprising: Receiving a second DCI; And Determining a second QCL assumption for an aperiodic CSI-RS for the second DCI, wherein: If a scheduling offset of the second DCI is not lower than the scheduling offset threshold, the second QCL assumption is based on a QCL indication included in the second DCI; Or If the scheduling offset of the second DCI is lower than the scheduling offset threshold, the second QCL assumption is not determined based on the second DCI.

11. The method according to claim 9, wherein the second DCI is received in a multi-DCI mode, and wherein the method further comprises, for each respective CORESET pool among a plurality of control resource set (CORESET) pools: Determining a second QCL assumption for an aperiodic CSI-RS based on a QCL assumption for the CORESET with the lowest identifier in the latest time slot among the CORESETs in the respective CORESET pool.

12. The method according to claim 9, wherein the second DCI is received in a multi-DCI mode, and wherein the method further comprises: Determining a second QCL assumption for an aperiodic CSI-RS for the respective CORESET based on a QCL assumption for the CORESET with the lowest identifier in the latest time slot among the CORESETs in the same CORESET pool as the respective control resource set (CORESET).

13. The method according to claim 9, wherein the method further comprises: determining the first QCL assumption for the aperiodic CSI-RS, at least partially based on whether the aperiodic CSI-RS includes the following: CSI-RS for beam management; CSI-RS for tracking; or CSI-RS for CSI acquisition.

14. The method according to claim 9, wherein the method further comprises: providing the cellular base station with the capability information of the wireless device, wherein the capability information indicates the method for determining the aperiodic CSI-RS QCL assumption supported by the wireless device.

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