UE beam switching synchronization

Abstract

A base station can receive an active notification from a user equipment (UE) that the UE will perform a beam switch from a first UE beam to a second UE beam. In response, the base station can determine a beam switch time slot on which the UE will perform a synchronized beam switch and perform a link transient mitigation operation for communications with the UE after the UE beam switch and until channel state information associated with the new UE beam is updated. The base station can then receive channel state information feedback from the UE for a channel associated with the second UE beam and adjust downlink data transmission parameters to align with the second UE beam based on the received channel state information feedback (CSF). The base station can also adjust uplink data transmission parameters based on sounding reference signals transmitted by the UE on the second UE beam.

Description

[0001] Related applications

[0002] This application claims the benefit of priority to U.S. Patent Application No. 17 / 149,536, filed January 14, 2021, the entire contents of which are incorporated herein by reference.

[0003] background

[0004] In Long Term Evolution (LTE), fifth-generation (5G) New Radio (NR) and other communication systems utilize the millimeter-wave (mmWave) band to provide high-bandwidth communication links for user equipment (UEs). The mmWave band is susceptible to free-space path loss and atmospheric absorption. To mitigate these issues, 5G NR mmWave communication systems utilize beamforming technology to generate highly directional signals, known as beams. Both the transmitting and receiving devices tune their respective antenna arrays to form directional beams.

[0005] Currently, beam selection, UE beam reselection, and UE beam tracking procedures are performed autonomously by the radio equipment, referred to herein as the User Equipment (UE). The base station serving the UE does not receive any information about this UE behavior or its timing. When a UE performs a beam switch, the physical channel, its characteristics, and capacity change, and some transmit parameters used by the base station and the UE may no longer be optimal and may be inconsistent with the new channel obtained after the UE beam switch for a period of time until updated Channel State Information (CSI) becomes available, resulting in link transients that may degrade communication link performance.

[0006] Overview

[0007] The aspects include systems and methods performed by a base station and a UE for synchronizing or coordinating UE beam switching and performing link transient mitigation after UE beam switching. Some aspects may include: receiving from the UE via a serving beam an active notification that the UE will perform a beam switch from a first UE beam to a second UE beam; determining, based on the received notification, the UE beam switching time slot on which the UE will perform the beam switch; performing link transient mitigation operations from the beam switching time slot for communication with the UE on the serving beam; receiving from the UE a channel state information feedback (CSF) for a channel associated with the second UE beam; and adjusting data communication parameters, at least in part, based on the received CSF, to align with the channel associated with the second UE beam.

[0008] Some aspects may include: stopping the execution of link transient mitigation operations for communication with the UE on the serving beam after receiving the CSF from the UE. In some aspects, performing link transient mitigation operations for communication with the UE on the serving beam from the UE beam switching time slot may include: reducing the modulation and coding scheme (MCS) for communication with the UE. In some aspects, performing link transient mitigation operations for communication with the UE on the serving beam from the UE beam switching time slot may include: increasing the MCS margin of the external link adaptation loop for communication with the UE. In some aspects, performing link transient mitigation operations for communication with the UE on the serving beam from the UE beam switching time slot may include: using single-layer transmission for communication with the UE. In some aspects, performing link transient mitigation operations for communication with the UE on the serving beam from the UE beam switching time slot may include: performing link transient mitigation operations for communication with the UE until the data transmission parameters are adjusted based on the received CSF or based on the received SRS associated with the channel obtained using the second UE beam.

[0009] Some aspects may include: allocating resources for the Channel State Indicator Reference Signal (CSI-RS) during the UE beam switching time slot or during the next available downlink time slot; and transmitting information about scheduling CSFs to the UE, wherein the CSFs are based on the CSI-RS. In such an aspect, adjusting data communication parameters based on the received CSFs to align with the channel associated with the second UE beam may include: avoiding scheduling downlink data transmission to the UE from the start of the UE beam switching time slot until the data transmission parameters are adjusted based on the received CSFs.

[0010] Some aspects may include: transmitting information to the UE during the UE beam switching time slot or during the next available uplink time slot; and receiving the SRS from the UE. Such aspects may include: adjusting parameters for uplink data transmission from the UE on the second UE beam obtained after the UE beam switching based on the SRS; and avoiding scheduling uplink data transmission from the UE from the UE since the UE beam switching time slot until after adjusting the parameters for uplink data transmission from the UE on the second UE beam.

[0011] Some aspects may include: transmitting information to the UE during the UE beam-switching time slot or during the next available downlink time slot to schedule the transmission of an aperiodic tracking reference signal (TRS) so that the UE can refine the estimation of channel characteristics associated with the serving beam acquired after the UE beam-switching; and transmitting the aperiodic TRS to the UE according to the scheduling information. In some aspects, determining the UE beam-switching time slot on which the UE will perform a beam-switching based on received notification may include: determining the UE beam-switching time slot based on the time slot and time slot offset on which the base station receives notification that the UE will perform a beam-switching. Some aspects may include: executing a P2 beam management procedure for beam refinement of the serving base station beam after the UE beam-switching to the second UE beam and starting from the UE beam-switching time slot. In various embodiments, the UE beam-switching time slot may be an uplink or downlink time slot. In some embodiments, resources for CSI-RS, TRS, and / or P2 may be scheduled on a first downlink time slot available after the UE beam-switching. In some embodiments, resources for SRS can be scheduled in the first uplink time slot available after the UE beam switching.

[0012] Further aspects may include a base station having a processor configured to perform one or more operations of any of the methods outlined above. Further aspects include processing means for use in a base station configured with processor-executable instructions for performing operations of any of the methods outlined above. Further aspects include a non-transient processor-readable storage medium having processor-executable instructions stored thereon, the processor-executable instructions being configured to cause a processor of the base station to perform operations of any of the methods outlined above. Further aspects include a base station having means for performing functions of any of the methods outlined above. Further aspects include a system-on-a-chip for use in a base station, the system-on-a-chip including a processor configured to perform one or more operations of any of the methods outlined above.

[0013] The aspects include systems and methods performed by the UE for UE beam switching synchronization and link transient mitigation after UE beam switching. Some aspects may include: determining that a UE beam switching is required; in response to determining that a UE beam switching is required, sending an active notification to a base station that the UE will perform a beam switching from a first UE beam to a second UE beam; performing the beam switching from the first UE beam to the second UE beam in a UE beam switching time slot; receiving from the base station control information allocating CSI-RS resources in the UE beam switching time slot for CSF for a channel associated with the second UE beam; receiving aperiodic CSI-RS from the base station using the second UE beam; determining a CSF including information about the channel associated with the second UE beam based on the CSI-RS; transmitting a CSF assessment to the base station using the allocated CSI-RS resources; and receiving from the base station instructions to adjust data communication parameters and align with the channel associated with the second UE beam, at least in part, based on the transmitted CSF.

[0014] Some aspects may include: receiving information from the base station during the UE beam switching time slot or during the next available uplink time slot; transmitting the SRS to the base station; and receiving instructions from the base station to adjust data communication parameters for uplink data transmission on the second UE beam based on the SRS. Some aspects may include: receiving information from the base station during the UE beam switching time slot or during the next available downlink time slot; receiving the TRS according to the information on the scheduled aperiodic TRS; and refining the estimation of channel characteristics associated with the serving beam obtained after the UE beam switching to the second UE beam.

[0015] A further aspect includes a UE having a processor configured to perform one or more operations of any of the methods outlined above. A further aspect includes processing devices for use in a UE, the processing devices being configured with processor-executable instructions for performing operations of any of the methods outlined above. A further aspect includes a non-transient processor-readable storage medium having processor-executable instructions stored thereon, the processor-executable instructions being configured to cause a processor of the UE to perform operations of any of the methods outlined above. A further aspect includes a UE having means for performing functions of any of the methods outlined above. A further aspect includes a system-on-a-chip for use in a UE, the system-on-a-chip including a processor configured to perform one or more operations of any of the methods outlined above. Brief description of the attached diagram

[0017] Figure 1 This is a system block diagram illustrating an example communication system applicable to implementing any of the various embodiments.

[0018] Figure 2A This is a component block diagram illustrating an example computing and wireless modem system applicable to implementing any of the various embodiments.

[0019] Figure 2B This is a component block diagram illustrating an mmWave receiver applicable to implementing any of the various embodiments.

[0020] Figure 2C This is a block diagram illustrating the components of an mmWave transmitter applicable to implementing any of the various embodiments.

[0021] Figure 3 This is a component block diagram illustrating a software architecture, including a radio protocol stack for the user plane and control plane in wireless communication, applicable to implementing any of the various embodiments.

[0022] Figure 4A This is a component block diagram illustrating the components and processing modules of the base station applicable to various embodiments.

[0023] Figure 4B This is a component block diagram illustrating the components and processing modules of the UE applicable to various embodiments.

[0024] Figure 5A This is a flowchart illustrating the methods executed by the base station's processor for UE beam switching synchronization and link transient mitigation after UE beam switching, according to various embodiments.

[0025] Figure 5B , 5C 5D is a process flow diagram illustrating operations that can be performed as part of methods for UE beam switching synchronization and link transient mitigation after UE beam switching, according to various embodiments.

[0026] Figure 6A This is a flowchart illustrating the methods executed by the UE's processor for UE beam switching synchronization and link transient mitigation after UE beam switching, according to various embodiments.

[0027] Figure 6B and 6C The description explains the operations that can be performed as part of methods for UE beam switching synchronization and link transient mitigation after UE beam switching, according to various embodiments.

[0028] Figure 7 This is a component block diagram of a base station computing device applicable to various embodiments.

[0029] Figure 8 This is a component block diagram of the UE applicable to various embodiments.

[0030] Detailed description

[0031] Various embodiments will be described in detail with reference to the accompanying drawings. Where possible, the same reference numerals will be used throughout the drawings to refer to the same or similar parts. References to specific examples and implementations are for illustrative purposes and are not intended to limit the scope of the claims.

[0032] Various embodiments include systems and methods for synchronizing UE beam switching between a UE and a base station to improve communication between the UE and a base station serving the UE (i.e., communicating with the UE) by mitigating link transients caused by beam switching performed by the UE. In various embodiments, the UE may send an active notification to the base station regarding its intention to perform beam switching. Based on this notification, the base station may implement one or more link transient mitigation measures. Furthermore, the base station and / or the UE may send information and / or instructions to another device to enable rapid adjustment of data communication parameters for a new composite serving beam obtained after the UE performs beam switching.

[0033] Various embodiments can improve communication link stability and reduce the probability of beam failure or communication link failure. Various embodiments can improve beam tracking capabilities and consequently lead to higher link efficiency. Various embodiments can improve mobility support for mmWave communication.

[0034] The term “User Equipment” (“UE”) is used herein to refer to any of a variety of wireless devices, including, for example: wireless router devices, wireless appliances, cellular phones, smartphones, portable computing devices, personal or mobile multimedia players, laptop computers, tablet computers, smartbooks, ultrabooks, handheld computers, wireless email receivers, Internet-enabled multimedia cellular phones, medical devices and equipment, biosensors / devices, wearable devices (including smartwatches, smart clothing, smart glasses, smart wristbands, smart jewelry (e.g., smart rings and smart bracelets, etc.)), entertainment devices (e.g., wireless game controllers, music and video players, satellite radios, etc.), Internet of Things (IoT) devices with wireless networks enabled (including smart meters / sensors, industrial manufacturing equipment, large and small machines and appliances for home or business use), wireless communication elements in autonomous and semi-autonomous vehicles, wireless devices attached to or incorporated into various mobile platforms, GPS devices, and similar electronic devices including memory, wireless communication components, and programmable processors.

[0035] The term "System-on-a-Chip" (SOC) is used herein to refer to a single integrated circuit (IC) chip containing multiple resources or processors integrated on a single substrate. A single SOC may contain circuitry for digital, analog, mixed-signal, and radio frequency functions. A single SOC may also include any number of general-purpose or special-purpose processors (digital signal processors, modem processors, video processors, etc.), memory blocks (such as ROM, RAM, flash memory, etc.), and resources (such as timers, voltage regulators, oscillators, etc.). Each SOC may also include software for controlling the integrated resources and processors, as well as software for controlling peripheral devices.

[0036] The term "System-in-Package" (SIP) may be used herein to refer to a single module or package containing multiple resources, computing units, cores or processors on two or more IC chips, a substrate, or a System-on-a-Chip (SoC). For example, a SIP may include a single substrate on which multiple IC chips or semiconductor dies are stacked in a vertical configuration. Similarly, a SIP may include one or more multi-chip modules (MCMs) on which multiple ICs or semiconductor dies are packaged into a unified substrate. A SIP may also include multiple independent SoCs coupled together and packaged adjacently (e.g., on a single motherboard or within a single UE) via high-speed communication circuitry. The proximity of the SoCs facilitates high-speed communication and the sharing of memory and resources.

[0037] As used herein, the terms “network,” “system,” “wireless network,” “cellular network,” and “wireless communication network” can be used interchangeably to refer to a portion or all of an operator’s wireless network associated with a UE and / or a subscription on the UE. The techniques described herein can be used in a variety of wireless communication networks, such as Code Division Multiple Access (CDMA), Time Division Multiple Access (TDMA), FDMA, Orthogonal FDMA (OFDMA), Single Carrier FDMA (SC-FDMA), Global System for Mobile Communications (GSM), and others. Generally, any number of wireless networks can be deployed in a given geographic area. Each wireless network can support at least one radio access technology, which can operate on one or more frequencies or frequency ranges. For example, a CDMA network can implement Universal Terrestrial Radio Access (UTRA) (including the Wideband Code Division Multiple Access (WCDMA) standard), CDMA2000 (including the IS-2000, IS-95, and / or IS-856 standards), etc. In another example, a TDMA network can implement GSM Enhanced Data Rate (EDGE) for GSM evolution. In another example, OFDMA networks can implement Evolved UTRA (E-UTRA) (including the LTE standard), IEEE 802.11 (WiFi), IEEE 802.16 (WiMAX), IEEE 802.20, Flash-OFDM, etc. References to wireless networks using the LTE standard are possible, and therefore the terms "Evolved Universal Terrestrial Radio Access," "E-UTRAN," and "eNodeB" can be used interchangeably herein to refer to wireless networks. However, such references are provided merely as examples and are not intended to exclude wireless networks using other communication standards. For example, while various third-generation (3G), fourth-generation (4G), and fifth-generation (5G) systems are discussed herein, those systems are cited only as examples and can be replaced by future generations of systems (e.g., sixth-generation (6G) or higher) in various examples.

[0038] 5G NR mmWave communication systems utilize beamforming technology to transmit and receive highly directional beams. The optimal combination of transmit and receive beams can be determined by the system, and this combination is used as a composite beam (sometimes called the serving beam) for the transmission of control and data signals (e.g., via the Physical Downlink Control Channel (PDCCH) and / or the Physical Downlink Shared Channel (PDSCH)). To achieve efficient and reliable communication over time, the system can adaptively identify and track the optimal combination of transmit and receive beams.

[0039] Currently, beam selection, beam reselection, and beam tracking procedures are performed autonomously by the UE. The base station serving the UE does not receive any information about this UE behavior or its timing. However, each time a UE performs a beam switch, the physical channel, as well as its characteristics and capacity, changes. Therefore, when a UE performs a beam switch, the transmit and receive parameters of the base station and the UE may be mismatched for a period of time. Some transmit parameters of the base station and the UE may no longer be optimal and may be inconsistent with the new channel obtained after the UE beam switch for a period of time until updated CSI information becomes available, resulting in link transients. For example, previous transmit parameters may not be aligned with the new channel, and previously known CSI may be invalidated by the UE beam switch. Communication link performance may degrade during link transients.

[0040] Channel State Information (CSI) can be used to determine channel conditions and assist in link adaptation procedures for serving beams to maintain reliable and efficient communication between the base station and the UE. For the downlink portion of the communication link, the UE can provide Channel State Information Feedback (CSF) to the base station, which may include, for example, a Rank Indicator (RI), a Precoding Matrix Indicator (PMI), a Channel Quality Indicator (CQI), and / or other information. The base station can use the CSF to perform one or more link adaptation operations.

[0041] However, when a UE performs a beam switch, the physical channel characteristics and capacity may change for both the uplink and downlink portions of the communication link. Previously reported CSFs may no longer be valid for the new composite beam (i.e., after the UE changes its beam). As a result, communication link performance may be degraded due to a mismatch between outdated CSFs and new channel state information during the period from when the UE performs a beam switch until the UE sends a new, updated CSF report to the base station that allows adjustment of transmission parameters for the new channel acquired in the downlink and associated with the new composite (serving) beam. Even when the UE is not highly mobile (i.e., even in low UE mobility scenarios), the UE beam switching rate can still be significant due to UE rotation and changes in the UE environment. Each UE beam change can potentially degrade communication link quality (i.e., reliability) over a certain time duration (e.g., transient periods), or in some extreme cases, even lead to link failure events. For example, the MCS may become unreliable due to PMI mismatch. In some scenarios, base stations can perform external link adaptation loop operations and / or reduce the MCS to quickly recover from poor link reliability conditions; however, if such steps are not performed quickly enough (e.g., external link adaptation responses typically have some latency), this scenario can lead to communication link failures or beam failure events. In the case of a link failure, the UE may need to reconnect to the communication network. In some cases, RI (Rank Indicator) mismatch can cause communication link failures. For example, if RI=2 is used before the UE beam switch, but the channel obtained after the UE beam switch only allows RI=1 (e.g., high correlation between two polarities received by the second device beam, or only a single polarity is correctly received on the second UE beam), and RI=1 should have been used after the UE beam switch (e.g., reflecting the stronger Reference Signal Received Power (RSRP) characteristics of the second UE beam, but with a lower rank), the network may be unable to transmit two streams on a channel with RI=1. These and other problems can be caused by asynchronous UE beam switching, which may be followed by potential link transients or temporary link reliability issues.

[0042] As another example, the UE can perform beam selection and tracking based on the Synchronization Signal Block (SSB) signal. In some cases, such as for P3 beam management operations, the UE can utilize a special beam management channel state indicator reference signal (CSI-RS). According to current technical specifications, beam management (including UE beam selection and tracking) is typically based on the Reference Signal Received Power (RSRP) criterion using a single receive port reference signal. The beam management CSI-RS signal used for P3 operations can be assigned to a single port (two-port assignment is also permitted, but is generally not used), and the SSB signal can utilize a single port. Millimeter-wave signals can use both horizontal and vertical polarization, which are generally well separated and result in a rank=2 channel, and for most UEs, two-layer transmission (i.e., for the maximum value of mmWave signals) is more likely (e.g., where the signal-to-noise ratio (SNR) is greater than a threshold SNR). In some cases, depending on the selected beam (or the antenna module used), it is possible for the UE to receive a stronger beam (i.e., with higher RSRP) that only allows a single dominant polarization or a strongly correlated polarization that only allows a channel with RI=1.

[0043] When a UE performs a UE beam change, the new beam (i.e., the second beam) is most likely to have a different and / or more suitable PMI compared to a currently used (or known) beam based on the last CSF update. However, because the base station is unaware that the UE has performed a beam change, it may continue to use the PMI and RI selected for the previous beam (i.e., the old UE beam or the first UE beam). This mismatch can lead to downlink quality degradation (referred to herein as link transients) at least until the next opportunity for the UE to report a CSF to the base station. Similarly, this mismatch can lead to link transients in the uplink portion of the communication link at least until the next opportunity for the UE to transmit a probe reference signal (SRS) to the base station on the new UE beam (the second UE beam). In cases where the base station and UE utilize two-layer communication, PMI mismatch can introduce higher sensitivity than in single-layer transmission cases. In the case where the new composite beam (i.e., the beam obtained by utilizing the second UE beam) has a rank indicator of 1 (i.e., RI=1), the severity of link transients may be even higher, even if the new beam has a higher RSRP, especially when downlink data communication is performed using two-layer communication (e.g., based on the old CSF report).

[0044] Various embodiments include methods and systems for mitigating the negative impacts of link transients that may accompany UE beam switching. In some embodiments, these methods may be applied in conjunction with, as part of, or related to P3 beam management procedures. Alternatively or additionally, synchronization signal block (SSB) resources may be used to perform UE procedures for beam selection, beam refinement, and beam tracking.

[0045] In various embodiments, a UE beam management algorithm executed on the UE can determine that a UE beam handover is required. For example, the UE can determine that there exists a beam (second UE beam) that is superior to the currently used serving beam (first UE beam). In response, the UE can (e.g., via the serving beam) send an active indication to the base station that the UE will perform a beam handover from the first UE beam to the second UE beam. In some embodiments, the time slot in which the UE sends this indication to the base station can be referred to as time slot n. In some embodiments, the UE can send the indication in uplink control information (UCI), which can be encoded and transmitted via the physical uplink control channel (PUCCH) or the physical uplink shared channel (PUSCH). In some embodiments, the UE can transmit the indication in a manner similar to ACK-NACK or scheduling request (SR) bits. The UE can perform the beam handover during a UE beam handover time slot N time slots after time slot n (i.e., during time slot n+N, where N represents the time slot offset). In other words, the UE can perform beam switching on a time slot index having an N-slot offset relative to the time slot in which the UE beam switching indication is transmitted. In this way, the UE beam switching time slot can be synchronized between the base station and the UE, as further described below. In some embodiments, the time slot offset N can be a value defined in the technical specifications. In some embodiments, the time slot offset N can be configured in the memories of the base station and the UE. In some embodiments, the UE beam switching time slot can be any type of time slot, such as downlink time slots and uplink time slots, or a hybrid time slot. In some embodiments, the execution of UE beam switching may not occupy the entire time slot and can be performed very quickly (e.g., within tens of nanoseconds). In some embodiments, the base station can “assume” (e.g., via the execution of the operation) that the UE will perform beam switching exactly before the first OFDM (Orthogonal Frequency Division Multiplexing) symbol of the UE beam switching time slot for downlink and / or uplink signal reception or transmission by the UE. In some embodiments, the base station can determine that the execution of UE beam switching occurs (or has already occurred) exactly before the first OFDM symbol for both downlink and uplink signaling.

[0046] In various embodiments, the base station may receive an active UE beam switching notification and may perform link transient mitigation operations (or one or more link transient mitigation operations). In some embodiments, starting in the UE beam switching slot (e.g., slot n+N), the base station may reduce the modulation and coding scheme (MCS) for data communication with the UE in the uplink and / or downlink (i.e., in the PDSCH and / or PUSCH) to make it more robust to changing channel conditions and misaligned transmission parameters. In some embodiments, this may include an active external link adaptation (OLA) loop response. In some embodiments, the base station may transmit control information to the UE (before or during the UE beam switching slot) that allocates CSI-RS resources on the UE beam switching slot for Channel State Information Feedback (CSF) evaluation of the channel associated with the second UE beam. In some embodiments, the control information may instruct the CSF evaluation transmission time and CSF reporting configuration.

[0047] In some embodiments, the base station may use a reduced MCS for data communication from the UE beam switching time slot until the base station receives a new CSF (e.g., an updated assessment or report of CSI) associated with the second UE beam. In some embodiments, the base station may use a reduced MCS for data communication from the UE beam switching time slot until the base station receives the next SRS from the UE. In some embodiments, starting in the UE beam switching time slot (e.g., time slot n+N), the base station may configure a higher MCS margin for communication to and / or from the UE to reduce the likelihood of communication link failure or beam failure. In some embodiments, starting from the UE beam switching time slot and until the next CSF report and / or SRS, the base station may utilize single-layer transmission for communication to the UE to reduce sensitivity to potential RI and / or PMI mismatches. In some embodiments, the base station may perform transient mitigation operations until the next CSF report is received from the UE.

[0048] In some embodiments, the base station may utilize allocated AP CSI-RS resources during the UE beam switching time slot or during the next available downlink time slot to schedule (i.e., send scheduling information to the UE) aperiodic (AP) Channel State Indicator (CSI) reports (i.e., CSFs). The base station may transmit the CSI-RS to be received at the UE side using the UE's second beam (i.e., the new beam) during the UE beam switching time slot, and the UE may send an updated CSF to the base station based on the CSI-RS. The base station may then adjust the communication parameters (e.g., MCS, PMI, and / or RI) for the channel associated with the second UE beam based on the CSF. Providing CSI-RS and CSF scheduling in this manner can reduce potential link transients to a relatively small number of destination time slots (also known as CSF turnaround time). In some embodiments, the base station may avoid scheduling transmissions to the UE (e.g., data transmissions) until the data transmission parameters are adjusted based on the received CSF.

[0049] In some embodiments, the base station may schedule aperiodic SRS for the UE during the UE beam switching time slot or during the next available uplink time slot (i.e., may send scheduling information for aperiodic SRS to the UE). The UE may transmit aperiodic SRS to the base station based on the scheduling information. In some embodiments, the base station may process the aperiodic SRS and may determine updated uplink data channel (e.g., PUSCH) transmission parameters for the UE that are aligned with the new UE beam (or a new associated composite / serving uplink (UL) beam). Scheduling aperiodic SRS in this manner and determining updated uplink data channel parameters can reduce potential link transients to a relatively small number of destination time slots (also known as SRS turnaround time). In some embodiments, the base station may avoid scheduling uplink data transmission from the UE until after adjusting the parameters for uplink data transmission from the UE on a new channel associated with the second UE beam in the uplink.

[0050] In some embodiments, the base station may schedule an aperiodic tracking reference signal (TRS) during the UE beam switching time slot or during the next available downlink time slot (i.e., scheduling information for the aperiodic tracking reference signal (TRS) may be transmitted). The base station may transmit the aperiodic TRS based on the scheduling information. The UE may receive and process the aperiodic TRS, and based on the aperiodic TRS, the UE may refine the estimation of the channel characteristics of the channel associated with the second UE beam. In some embodiments, the base station may perform a P2 beam management operation on the downlink time slot after the UE beam switching time slot to perform beam refinement on the new serving beam obtained using the second UE beam after the beam switching performed by the UE.

[0051] Figure 1 This is a system block diagram illustrating an example communication system 100. Communication system 100 can be a 5G New Radio (NR) network, or any other suitable network (such as a Long Term Evolution (LTE) network). Although Figure 1 The 5G network has been explained, but subsequent networks may include the same or similar elements. Therefore, the references to 5G networks and 5G network elements in the following description are for illustrative purposes and are not intended to be limiting.

[0052] Communication system 100 may include a heterogeneous network architecture, which includes a core network 140 and various UEs (in...). Figure 1 The core network 100 is referred to as UE 120a-120e. The communication system 100 may also include several base stations (referred to as BS 110a, BS 110b, BS 110c, and BS 110d) and other network entities. A base station is an entity that communicates with the UE and may also be referred to as a B-node, an LTE evolved B-node (eNodeB or eNB), an access point (AP), a radio headend, a transmit / receive point (TRP), a new radio base station (NR BS), a 5G B-node (NB), a next-generation B-node (gNodeB or gNB), and so on. Each base station provides communication coverage for a specific geographic area. In 3GPP, the term "cell" can refer to the coverage area of ​​a base station, the base station subsystem serving that coverage area, or a combination thereof, depending on the context in which the term is used. The core network 140 can be any type of core network, such as an LTE core network (e.g., an EPC network), a 5G core network, etc.

[0053] Base stations 110a-110d can provide communication coverage for macrocells, picocells, femtocells, another type of cell, or a combination thereof. Macrocells can cover a relatively large geographic area (e.g., a radius of several kilometers) and allow unrestricted access by UEs with a service subscription. Picocells can cover a relatively small geographic area and allow unrestricted access by UEs with a service subscription. Femtocells can cover a relatively small geographic area (e.g., a residential area) and allow restricted access by UEs associated with that femtocell (e.g., UEs in a Closed Subscriber Group (CSG)). A base station used for a macrocell may be referred to as a macro BS. A base station used for a picocell may be referred to as a pico BS. A base station used for a femtocell may be referred to as a femtocell BS or a home BS. Figure 1In the example described, base station 110a can be a macro BS for macro cell 102a, base station 110b can be a pico BS for pico cell 102b, and base station 110c can be a femto BS for femto cell 102c. Base stations 110a-110d can support one or more (e.g., three) cells. The terms “eNB,” “base station,” “NR BS,” “gNB,” “TRP,” “AP,” “B node,” “5G NB,” and “cell” are used interchangeably herein.

[0054] In some examples, the cell may not be stationary, and the geographical area of ​​the cell may move depending on the location of the mobile base station. In some examples, base stations 110a-110d may interconnect with each other and with one or more other base stations or network nodes (not described) in communication system 100 using any suitable transport network through various types of backhaul interfaces (such as direct physical connections, virtual networks, or combinations thereof).

[0055] Base stations 110a-110d can communicate with the core network 140 via wired or wireless communication link 126. UEs 120a-120e can communicate with base stations 110a-110d via wireless communication link 122.

[0056] The wired communication link 126 can use various wired networks (such as Ethernet, TV cable, telephone, fiber optic, and other forms of physical network connection) that can use one or more wired communication protocols, such as Ethernet, point-to-point protocol, high-level data link control (HDLC), advanced data communication control protocol (ADCCP), and transmission control protocol / internet protocol (TCP / IP).

[0057] The communication system 100 may also include relay stations (such as relay BS 110d). A relay station is an entity capable of receiving data transmissions from an upstream station (e.g., a base station or a UE) and transmitting those data transmissions to a downstream station (e.g., a UE or a base station). A relay station can also be a UE capable of relaying transmissions for other UEs. Figure 1 In the example described, relay station 110d can communicate with macro base station 110a and UE 120d to facilitate communication between base station 110a and UE 120d. A relay station can also be referred to as a relay base station, relay, relay, etc.

[0058] The communication system 100 can be a heterogeneous network comprising different types of base stations (e.g., macro base stations, pico base stations, femto base stations, relay base stations, etc.). These different types of base stations may have different transmit power levels, different coverage areas, and different effects on interference in the communication system 100. For example, macro base stations may have high transmit power levels (e.g., 5 to 40 watts), while pico base stations, femto base stations, and relay base stations may have lower transmit power levels (e.g., 0.1 to 2 watts).

[0059] Network controller 130 can be coupled to a set of base stations and can provide coordination and control over these base stations. Network controller 130 can communicate with the base stations via backhaul. Base stations can also communicate with each other directly or indirectly, for example, via wireless or wired backhaul.

[0060] UEs 120a, 120b, and 120c can be distributed throughout the communication system 100, and each UE can be stationary or mobile. UEs can also be referred to as access terminals, terminals, mobile stations, subscriber units, stations, user equipment (UE), etc.

[0061] Macro base station 110a can communicate with communication network 140 on wired or wireless communication link 126. UEs 120a, 120b, and 120c can communicate with base stations 110a-110d on wireless communication link 122.

[0062] Wireless communication links 122 and 124 may include multiple carrier signals, frequencies, or frequency bands, each of which may include multiple logical channels. Wireless communication links 122 and 124 may utilize one or more radio access technologies (RATs). Examples of RATs that can be used in wireless communication links include: 3GPP LTE, 3G, 4G, 5G (such as NR), GSM, Code Division Multiple Access (CDMA), Wideband Code Division Multiple Access (WCDMA), Microwave Access Global Interoperability (WiMAX), Time Division Multiple Access (TDMA), and other mobile phone communication technology cellular RATs. Other examples of RATs that can be used in one or more of the various wireless communication links within communication system 100 include mid-range protocols (such as Wi-Fi, LTE-U, LTE-Direct, LAA, MuLTEfire) and relatively short-range RATs (such as ZigBee, Bluetooth, and Bluetooth Low Energy (LE)).

[0063] Some wireless networks (e.g., LTE) utilize Orthogonal Frequency Division Multiplexing (OFDM) on the downlink and Single-Carrier Frequency Division Multiplexing (SC-FDM) on the uplink. OFDM and SC-FDM divide the system bandwidth into multiple (K) orthogonal subcarriers, often referred to as frequency modulation, frequency slots, etc. Each subcarrier can be modulated with data. Generally, modulation symbols are transmitted in the frequency domain for OFDM and in the time domain for SC-FDM. The spacing between adjacent subcarriers can be fixed, and the total number of subcarriers (K) can depend on the system bandwidth. For example, the subcarrier spacing could be 15 kHz, and the minimum resource allocation (called a "resource block") could be 12 subcarriers (or 180 kHz). Therefore, for system bandwidths of 1.25, 2.5, 5, 10, or 20 MHz, the nominal Fast Fourier Transform (FFT) size could be 128, 256, 512, 1024, or 2048, respectively. The system bandwidth can also be divided into subbands. For example, a subband can cover 1.08 MHz (i.e., 6 resource blocks), and for system bandwidths of 1.25, 2.5, 5, 10, or 20 MHz, there can be 1, 2, 4, 8, or 16 subbands, respectively.

[0064] While some implementations may use terminology and examples associated with LTE technology, some implementations are applicable to other wireless communication systems, such as New Radio (NR) or 5G networks. NR can utilize OFDM with a cyclic prefix (CP) on both the uplink (UL) and downlink (DL) and includes support for half-duplex operation using Time Division Duplex (TDD). A single component carrier bandwidth of 100 MHz can be supported. NR resource blocks can span 12 subcarriers with a subcarrier bandwidth of 75 kHz over a duration of 0.1 milliseconds (ms). Each radio frame can include 50 subframes with a length of 10 ms. Therefore, each subframe can have a length of 0.2 ms. Each subframe can indicate the link direction for data transmission (i.e., DL or UL), and the link direction of each subframe can be dynamically switched. Each subframe can include DL / UL data and DL / UL control data. Beamforming can be supported and beam direction can be dynamically configured. Precoded multiple-input multiple-output (MIMO) transmission can also be supported. The MIMO configuration in DL can support up to 8 transmit antennas (with up to 8 streams of multilayer DL transmission) and up to 2 streams per UE. Multilayer transmission with up to 2 streams per UE is supported.

[0065] Up to eight serving cells can be used to support the aggregation of multiple cells. Alternatively, NR can support different air interfaces in addition to the OFDM-based air interface.

[0066] Some UEs can be considered machine-type communication (MTC) devices or evolved or enhanced machine-type communication (eMTC) UEs. MTC and eMTC UEs include, for example, robots, drones, remote devices, sensors, meters, monitors, location tags, etc., which can communicate with a base station, another device (e.g., a remote device), or some other entity. Wireless computing devices can provide connectivity to or to a network (e.g., a wide area network, such as the Internet) or a cellular network, for example, via wired or wireless communication links. Some UEs can be considered Internet of Things (IoT) devices or can be implemented as NB-IoT (Narrowband Internet of Things) devices. UEs 120a-120e can be included within a housing that houses the components of UEs 120a-120e, such as processor components, memory components, similar components, or combinations thereof.

[0067] Generally, any number of communication systems and wireless networks can be deployed in a given geographical area. Each communication system and wireless network can support a specific Radio Access Technology (RAT) and can operate on one or more frequencies. A RAT can also be referred to as a radio technology, air interface, etc. A frequency can also be referred to as a carrier, frequency channel, etc. Each frequency can support a single RAT in a given geographical area to avoid interference between communication systems using different RATs. In some cases, 4G / LTE and / or 5G / NR RAT networks can be deployed. For example, a 5G Non-Self-Aggressive (NSA) network can use a 4G / LTE RAT on the 4G / LTE RAN side of a 5G NSA network, and simultaneously use a 5G / NR RAT on the 5G / NR RAN side of the 5G NSA network. The 4G / LTE RAN and 5G / NR RAN can be interconnected and connected to the 4G / LTE core network (e.g., an evolved packet core (EPC) network) in the 5G NSA network. Other example network configurations may include a 5G self-reliant (SA) network, in which the 5G / NR RAN is connected to the 5G core network.

[0068] In some implementations, two or more UEs (e.g., referred to as UE 120a and UE 120e) may communicate directly using one or more sidelink channels (e.g., without using base stations 110a-d as intermediaries). For example, UEs 120a-e may communicate using peer-to-peer (P2P) communication, device-to-device (D2D) communication, vehicle-to-everything (V2X) protocols (which may include vehicle-to-vehicle (V2V) protocols, vehicle-to-infrastructure (V2I) protocols, or similar protocols), mesh networks, or similar networks, or combinations thereof. In this scenario, UEs 120a-120e may perform scheduling operations, resource selection operations, and other operations described elsewhere herein as performed by base stations 110a-110d.

[0069] Figure 2A This is a component block diagram illustrating an example computing and wireless modem system 200 suitable for implementing any of the various embodiments. The various embodiments can be implemented on several single-processor and multi-processor computer systems, including system-on-a-chip (SOC) or system-in-package (SIP) systems.

[0070] Reference Figure 1 and 2A The illustrated example computing system 200 (which may be a SIP in some embodiments) includes two SOCs 202 and 204 coupled to a clock 206, a voltage regulator 208, and a wireless transceiver 266 configured to transmit and receive wireless communications to and from a UE (such as base station 110a) via an antenna (not shown). In some implementations, the first SOC 202 may operate as the central processing unit (CPU) of the UE, executing instructions by performing arithmetic, logic, control, and input / output (I / O) operations specified by instructions from a software application. In some implementations, the second SOC 204 may operate as a dedicated processing unit. For example, the second SOC 204 may operate as a dedicated 5G processing unit responsible for managing high-capacity, high-speed (such as 5Gbps) or ultra-high frequency shortwave length (such as 28GHz mmWave spectrum) communications.

[0071] The first SOC 202 may include a digital signal processor (DSP) 210, a modem processor 212, a graphics processor 214, an application processor 216, one or more coprocessors 218 (such as vector coprocessors) connected to one or more of these processors, memory 220, a custom circuit system 222, system components and resources 224, an interconnect / bus module 226, one or more temperature sensors 230, a thermal management unit 232, and a thermal power envelope (TPE) component 234. The second SOC 204 may include a 5G modem processor 252, a power management unit 254, an interconnect / bus module 264, multiple mmWave transceivers 256, memory 258, and various additional processors 260 (such as application processors, packet processors, etc.).

[0072] Each processor 210, 212, 214, 216, 218, 252, 260 may include one or more cores, and each processor / core may perform operations independently of other processors / cores. For example, the first SOC 202 may include a processor running a first type of operating system (such as FreeBSD, LINUX, OS X, etc.) and a processor running a second type of operating system (such as MICROSOFT WINDOWS 10). Furthermore, any or all of processors 210, 212, 214, 216, 218, 252, 260 may be included as part of a processor cluster architecture (such as a synchronous processor cluster architecture, an asynchronous or heterogeneous processor cluster architecture, etc.).

[0073] The first and second SOCs 202 and 204 may include various system components, resources, and custom circuitry for managing sensor data, analog-to-digital conversion, wireless data transmission, and performing other specialized operations, such as decoding data packets and processing encoded audio and video signals for display in a web browser. For example, the system components and resources 224 of the first SOC 202 may include power amplifiers, voltage regulators, oscillators, phase-locked loops, peripheral bridges, data controllers, memory controllers, system controllers, access ports, timers, and other similar components used to support processors and software clients running on the UE. System components and resources 224 or custom circuitry 222 may also include circuitry for interfacing with peripheral devices, such as cameras, electronic displays, wireless communication devices, external memory chips, etc.

[0074] The first and second SOCs 202 and 204 can communicate via interconnect / bus module 250. Various processors 210, 212, 214, 216, and 218 can be interconnected via interconnect / bus module 226 to one or more memory elements 220, system components and resources 224, custom circuitry 222, and thermal management unit 232. Similarly, processor 252 can be interconnected via interconnect / bus module 264 to power management unit 254, mmWave transceiver 256, memory 258, and various additional processors 260. Interconnect / bus modules 226, 250, and 264 may include arrays of reconfigurable logic gates or implement bus architectures (such as CoreConnect, AMBA, etc.). Communication can be provided by advanced interconnects such as high-performance on-chip networks (NoC).

[0075] The first or second SOC 202, 204 may further include input / output modules (not described) for communicating with external resources (such as clock 206 and voltage regulator 208). External resources (such as clock 206 and voltage regulator 208) may be shared by two or more internal SOC processors / cores.

[0076] In addition to the example SIP 200 discussed above, some implementations can also be implemented in a wide variety of computing systems, which may include a single processor, multiple processors, multi-core processors, or any combination thereof.

[0077] Figure 2B This is a block diagram illustrating the components of the mmWave receiver 270 applicable to various aspects, and Figure 2C This is a block diagram illustrating the components of the mmWave transmitter 290 applicable to various aspects. The mmWave receiver 270 and mmWave transmitter 290 can also be referred to as beamforming architectures. References Figure 1-2C mmWave receiver 270 and mmWave transmitter 290 can be used in UEs (e.g., 120a-120e, 200) or base stations (e.g., 110a-110d, 200).

[0078] In various embodiments, the UE may be configured with both an mmWave receiver 270 and an mmWave transmitter 290 (i.e., having both architectures), and may use one or both. As an example, the mmWave receiver 270 architecture and the mmWave transmitter 290 architecture may be part of the mmWave transceiver 256. Implementing a UE with multiple architectures solves the limitations of a single static architecture. One architecture may be efficient for a first communication set (e.g., using appropriate spectral efficiency, resolution, and / or power consumption, etc.), while another architecture may be efficient for a second communication set. Conversely, by using a single architecture to transmit and / or receive communications, a static selection of a single architecture can lead to inefficient use of computational, communication, network, and / or power resources.

[0079] Reference Figure 2B The mmWave receiver 270 includes an antenna array 274 comprising multiple antenna elements contained within one or more antenna panels. Figure 2B In this context, the value "N" represents the number of antenna elements in antenna array 274. Antenna array 274 may include multiple cross-polarized antennas (each represented by the symbol "X"). In some implementations, the UE may be configured with four dipole antennas (i.e., eight in total). Based on a selected beamforming codebook that can be converted into a set of phase shifts in an analog beamforming block, the UE can form beams A1 to up to A... N .

[0080] The mmWave receiver 270 can be configured to perform analog or hybrid beamforming. The signal received at antenna N of antenna array 274 at time t... The signal can be propagated to the hybrid beamforming circuit 276. Hybrid beamforming can be performed at radio frequency (RF) or intermediate frequency (IF) by the hybrid beamforming circuit 276. The hybrid beamforming circuit 276 may include a set of phase shifters 278 and adders 280 connected to some antenna elements. While analog and hybrid beamforming techniques are generally power-efficient, they can only receive signals in a few directions. If an mmWave signal is received outside the analog beam supported by the mmWave receiver 270, signal quality degradation or even beam failure may occur.

[0081] The mmWave receiver 270, applicable to various embodiments, can be configured to perform analog or hybrid beamforming. The mmWave receiver 270 can perform beamforming at a baseband frequency. In the mmWave receiver 270, the number of antenna elements (e.g., 1-N) of the antenna array 274 can correspond to the number of RF chains 272 (e.g., 1-N). RF In some embodiments, the UE may be configured with a high-resolution ADC (one per RF chain).

[0082] Reference Figure 2C The mmWave transmitter 290 may include an antenna array 274 comprising multiple antenna elements contained within one or more antenna panels. The mmWave transmitter 290 may include a hybrid beamforming circuit 282 that can receive n signals from N RF chains 272. The hybrid beamforming circuit 282 may include a set of splitters 284 and a set of phase shifters 278. The hybrid beamforming circuit 282 can transform the signals... The propagation is transmitted to antenna N of antenna array 274.

[0083] Figure 3 This is a component block diagram illustrating a software architecture 300 including a radio protocol stack for the user plane and control plane in wireless communication, applicable to implementing any of the various embodiments. (Refer to...) Figure 1-3UE 320 may implement software architecture 300 to facilitate communication between UE 320 (e.g., UE 120a-120e, 200) and base station 350 (e.g., base station 110a-110d) of a communication system (e.g., 100). In various embodiments, layers in software architecture 300 may form logical connections with corresponding layers in the software of base station 350. Software architecture 300 may be distributed among one or more processors (e.g., processors 212, 214, 216, 218, 252, 260). Although described with respect to a single radio protocol stack, in a multi-SIM (Subscriber Identity Module) UE, software architecture 300 may include multiple protocol stacks, each associated with a different SIM (e.g., in a dual-SIM wireless communication device, two protocol stacks are associated with two SIMs respectively). Although described below with reference to the LTE communication layer, software architecture 300 may support any of a variety of standards and protocols for wireless communication, and / or may include additional protocol stacks that support any of a variety of standards and protocols for wireless communication.

[0084] Software architecture 300 may include a Non-Access Layer (NAS) 302 and an Access Layer (AS) 304. NAS 302 may include functions and protocols supporting packet filtering, security management, mobility control, session management, and traffic and signaling between the UE's SIM(s) (such as SIM(s) 204) and its core network 140. AS 304 may include functions and protocols supporting communication between SIM(s) (such as SIM(s) 204) and entities of the supported access network (such as base stations). Specifically, AS 304 may include at least three layers (Layer 1, Layer 2, and Layer 3), each layer may contain various sublayers.

[0085] In the user plane and control plane, Layer 1 (L1) of AS 304 can be Physical Layer (PHY) 306, which supervises the functions of transmitting or receiving over the air interface via a wireless transceiver (e.g., 266). Examples of such Physical Layer 306 functions may include Cyclic Redundancy Check (CRC) appending, decoding blocks, scrambling and descrambling, modulation and demodulation, signal measurement, MIMO, etc. The Physical Layer may include various logical channels, including the Physical Downlink Control Channel (PDCCH) and the Physical Downlink Shared Channel (PDSCH).

[0086] In the user plane and control plane, Layer 2 (L2) of AS 304 can be responsible for the link between UE 320 and base station 350 on physical layer 306. In some implementations, Layer 2 may include Media Access Control (MAC) sublayer 308, Radio Link Control (RLC) sublayer 310, and Packet Data Convergence Protocol (PDCP) sublayer 312, each sublayer forming a logical connection terminated at base station 350.

[0087] In the control plane, Layer 3 (L3) of AS 304 may include a Radio Resource Control (RRC) sublayer 3. Although not shown, software architecture 300 may include additional Layer 3 sublayers and various upper layers above Layer 3. In some implementations, RRC sublayer 313 may provide functions including broadcasting system information, paging, and establishing and releasing RRC signaling connections between UE 320 and base station 350.

[0088] In some implementations, PDCP sublayer 312 can provide uplink functions including multiplexing between different radio bearers and logical channels, sequence numbering, handover data processing, integrity protection, cryptography, and header compression. In the downlink, PDCP sublayer 312 can provide functions including in-order delivery of data packets, duplicate data packet detection, integrity verification, cryptographic decoding, and header decompression.

[0089] In the uplink, RLC sublayer 310 can provide segmentation and concatenation of upper-layer data packets, retransmission of lost data packets, and Automatic Repeat Request (ARQ). In the downlink, RLC sublayer 310 functions may include reordering of data packets to compensate for out-of-order reception, reassembly of upper-layer data packets, and ARQ.

[0090] In the uplink, MAC sublayer 308 provides functions including multiplexing between logical and transport channels, random access procedures, logical channel prioritization, and hybrid ARQ (HARQ) operation. In the downlink, MAC layer functions may include intracellular channel mapping, demultiplexing, discontinuous reception (DRX), and HARQ operation.

[0091] While the software architecture 300 provides the ability to transmit data over a physical medium, it may further include at least one host layer 314 to provide data transmission services to various applications within the UE 320. In some implementations, application-specific functionality provided by the at least one host layer 314 may provide an interface between the software architecture and the general-purpose processor 206.

[0092] In other implementations, software architecture 300 may include one or more higher logical layers (such as transport, session, presentation, application, etc.) that provide host layer functionality. For example, in some implementations, software architecture 300 may include a network layer (such as the Internet Protocol (IP) layer) where logical connections terminate at a Packet Data Network (PDN) gateway (PGW). In some implementations, software architecture 300 may include an application layer where logical connections terminate at another device (such as an end-user equipment, server, etc.). In some implementations, software architecture 300 may further include a hardware interface 316 in AS 304 between physical layer 306 and communication hardware (such as one or more radio frequency (RF) transceivers).

[0093] Figure 4A and 4B This is a block diagram illustrating a system 400 configured for UE beam switching synchronization and post-UE beam switching link transient mitigation according to various embodiments. (Refer to...) Figures 1-4B System 400 may include base station 402 and UE 404 (e.g., 110a-110d, 120a-120e, 200, 320, 350). Base station 402 and UE 404 exchange wireless communications to establish wireless communication links 122, 124, 126.

[0094] Base station 402 and UE 404 may include one or more processors 428, 432 coupled to electronic storage 426, 430 and a wireless transceiver (e.g., 266). In base station 402 and UE 404, wireless transceiver 266 may be configured to receive messages transmitted in transit and pass such messages to processors(s) 428, 432 for processing. Similarly, processors 428, 432 may be configured to send messages for transmission to wireless transceiver 266 for transmission.

[0095] Referring to base station 402, processor 428 can be configured by machine-readable instructions 406. Machine-readable instructions 406 may include one or more instruction modules. Instruction modules may include computer program modules. Instruction modules may include one or more of the following: notification receiving module 408, beam switching time slot module 410, link transient mitigation module 412, CSF module 414, parameter adjustment module 416, or other instruction modules.

[0096] The notification receiving module 408 can be configured, for example, to receive from the UE via the serving beam via the wireless transceiver 266, an active notification that the UE will perform a beam switching from the first UE beam to the second UE beam.

[0097] The beam switching time slot module 410 can be configured to determine the UE beam switching time slot during which the UE will perform beam switching based on the received notification.

[0098] The link transient mitigation module 412 can be configured to perform link transient mitigation operations for communication with the UE on the serving beam during the UE beam switching time slot.

[0099] CSF module 414 can be configured to receive channel state information feedback (CSF) from the UE for the channel associated with the second UE beam.

[0100] The parameter adjustment module 416 can be configured to adjust data communication parameters based on the received CSF to align with the channel associated with the second UE beam.

[0101] Referring to computing device 404, processor 432 may be configured by machine-readable instructions 434. Machine-readable instructions 406 may include one or more instruction modules. Instruction modules may include computer program modules. Instruction modules may include one or more of the following: UE beam switching determination module 436, notification sending module 438, beam switching module 440, CSF scheduling module 442, CSI-RS module 444, CSF determination module 446, TX / RX module 448, or other instruction modules.

[0102] The UE beam switching determination module 436 can be configured to determine that UE beam switching is required.

[0103] The notification sending module 438 can be configured, for example, to send a notification to the base station via the wireless transceiver 266 regarding the UE performing a beam switching from the first UE beam to the second UE beam.

[0104] The beam switching module 440 can be configured to perform beam switching from the first UE beam to the second UE beam during the UE beam switching time slot.

[0105] CSI-RS allocation information module 442 can be configured to receive from the base station control information for allocating CSI-RS resources on the UE beam switching time slot for use with the CSF of the channel associated with the second UE beam.

[0106] CSI-RS module 444 can be configured to receive aperiodic CSI-RS from the base station using the second UE beam.

[0107] CSF determination module 446 can be configured to determine CSF based on CSI-RS, including information about the channel associated with the second UE beam.

[0108] The TX / RX module 448 can be configured to transmit CSF to the base station using CSF resources.

[0109] In some embodiments, base station 402 and UE 404 may be operatively linked via one or more electronic communication links (e.g., wireless communication links 122, 124, 126). It will be understood that this is not intended to be limiting, and the scope of this disclosure includes embodiments in which base station 402 and UE 404 may be operatively linked via some other communication medium.

[0110] Electronic storage devices 426 and 430 may include non-transient storage media that electronically store information. The electronic storage media of electronic storage devices 426 and 430 may include one or both of system storage integrated with base station 402 and UE 404 (i.e., inherently non-removable) and removable storage devices removably connected to base station 402 and UE 404 via, for example, a port (e.g., a Universal Serial Bus (USB) port, a FireWire port, etc.) or a drive (e.g., a disk drive, etc.). Electronic storage devices 426 and 430 may include one or more of the following: optically readable storage media (e.g., optical discs, etc.), magnetically readable storage media (e.g., magnetic tape, magnetic hard disk drives, floppy disk drives, etc.), charge-based storage media (e.g., EEPROM, RAM, etc.), solid-state storage media (e.g., flash drives, etc.), and / or other electronically readable storage media. Electronic storage devices 426 and 430 may include one or more virtual storage resources (e.g., cloud storage, virtual private networks, and / or other virtual storage resources). Electronic storage devices 426 and 430 may store software algorithms, information determined by processors 428 and 432, information received from base station 402 and UE 404, or other information that enables base station 402 and UE 404 to operate as described herein.

[0111] Processors 428 and 432 may be configured to provide information processing capabilities in base station 402 and UE 404. Thus, processors 428 and 432 may include one or more of a digital processor, an analog processor, digital circuitry designed to process information, analog circuitry designed to process information, a state machine, and / or other mechanisms for electronically processing information. Although processors 428 and 432 are described as a single entity, this is for illustrative purposes only. In some embodiments, processors 428 and 432 may include multiple processing units and / or processor cores. Processing units may be physically located within the same device, or processors 428 and 432 may represent the processing functionality of multiple devices operating collaboratively. Processors 428 and 432 may be configured to execute modules 408-416 and modules 436-448 and / or other modules via software; hardware; firmware; a combination of software, hardware, and / or firmware; and / or other mechanisms for configuring the processing capabilities on processors 428 and 432. As used herein, the term "module" can refer to any component or collection of components that performs the functionality belonging to that module. This can include one or more physical processors, processor-readable instructions, circuitry, hardware, storage media, or any other components during the execution of processor-readable instructions.

[0112] The description below of the functionality provided by the various modules 408-416 and 436-448 is for illustrative purposes and not intended to be limiting, as any of modules 408-416 and 436-448 may provide more or less functionality than described. For example, one or more of modules 408-416 and 436-448 may be eliminated, and some or all of their functionality may be provided by other modules 408-416 and 436-448. As another example, processors 428, 432 may be configured to execute one or more additional modules that may perform some or all of the functionality attributed to one of the modules 408-416 and 436-448.

[0113] Figure 5A This is a flowchart illustrating method 500a, executed by the base station's processor according to various embodiments, for UE beam switching synchronization and post-UE beam switching link transient mitigation synchronization. (Refer to...) Figure 1-5A The operation of method 500a can be performed by the processor (such as processor 210, 212, 214, 216, 218, 252, 260, 428) of the base station (such as base station 110a-110d, 200, 350, 402).

[0114] In block 502, the processor may (e.g., via a serving beam) receive an active notification from the UE regarding that the UE will perform a beam switching from a first UE beam to a second UE beam. The means for performing the functions in block 502 may include a processor (e.g., 210, 212, 214, 216, 218, 252, 260, 428) and a radio transceiver (e.g., 266).

[0115] In block 504, the processor may determine the UE beam-switching time slot on which the UE will perform a beam-switching based on a received notification. In some embodiments, the processor may determine the UE beam-switching time slot based on the time slot in which the base station receives the active notification regarding the UE's upcoming beam-switching and the time slot offset. In some embodiments, the processor may determine that the UE beam-switching time slot is a predetermined number of time slots away from where the processor receives the notification regarding the UE's upcoming beam-switching. In some embodiments, the processor may determine that the UE will perform a beam-switching at the beginning of the beam-switching time slot. In some embodiments, the processor may determine that the UE will perform a beam-switching at the beginning of a first time slot associated with a downlink or uplink symbol of that time slot. Means for performing the functions in block 504 may include a processor (e.g., 210, 212, 214, 216, 218, 252, 260, 428).

[0116] In block 506, the processor may perform link transient mitigation operations for communication with the UE on the serving beam from the UE beam switching time slot. In various embodiments, performing link transient mitigation operations from the UE beam switching time slot allows the processor to perform link transient mitigation after the UE performs a UE beam switch to a second UE beam. In some embodiments, the processor may reduce the modulation and coding scheme (MCS) for communication with the UE after the UE switches its beam to the second UE beam and before updated CSI information becomes available for the channel associated with the new UE beam. In some embodiments, the processor may increase the MCS margin for communication with the UE after the UE switches its beam to the second UE beam and before updated CSI becomes available. In some embodiments, the processor may use single-layer transmission for communication with the UE during the transient period. In some embodiments, the processor may perform link transient mitigation operations for communication with the UE after the UE switches to the second UE beam until data transmission parameters are adjusted based on the received CSF. The means for performing the operations in block 506 may include a processor (e.g., 210, 212, 214, 216, 218, 252, 260, 428) and a wireless transceiver (e.g., 266).

[0117] In block 508, the processor can receive channel state information feedback (CSF) from the UE for the channel associated with the second UE beam. The means for performing the functions in block 508 may include a processor (e.g., 210, 212, 214, 216, 218, 252, 260, 428) and a radio transceiver (e.g., 266).

[0118] In block 510, the processor can adjust data communication parameters based on the received CSF to align with the channel associated with the second UE beam. Means for performing the functions in block 510 may include a processor (e.g., 210, 212, 214, 216, 218, 252, 260, 428) and a wireless transceiver (e.g., 266).

[0119] In optional block 512, the processor can execute a P2 beam management procedure for beam refinement of the newly acquired composite / serving beam after a UE beam handover to a second UE beam and starting during the UE beam handover time slot. In various embodiments, the UE beam handover time slot can be an uplink or downlink time slot. In some embodiments, resources for CSI-RS, TRS, and / or P2 can be scheduled in a first downlink time slot available after the UE beam handover. In some embodiments, resources for SRS can be scheduled in a first uplink time slot available after the UE beam handover. In various embodiments, the processor can be configured to perform certain operations very quickly, such as updating the CSF (which requires scheduling CSI-RI resources), updating channel characteristics (which requires scheduling TRS resources), refining the serving beam (which requires scheduling P2 resources), and / or updating the uplink CSI (which requires uplink SRS transmission). To perform such operations quickly, the processor can schedule the required downlink resources in the first available downlink time slot after the UE performs a beam handover. Furthermore, the processor can schedule the required uplink resources on the first available uplink time slot after the UE performs a beam switching. In some embodiments, one or more of these operations can be scheduled in a later available downlink or uplink time slot that is relatively close in time to the UE beam switching time slot.

[0120] The means for performing the functions in optional box 512 may include a processor (e.g., 210, 212, 214, 216, 218, 252, 260, 428) and a wireless transceiver (e.g., 266).

[0121] In block 514, the processor may stop the execution of link transient mitigation operations for communication with the UE after receiving a CSF from the UE. In some embodiments, the CSF from the UE may represent a new channel obtained by the UE after a UE beam switching, such as a channel associated with a second UE beam. The means for performing the functions in block 514 may include a processor (e.g., 210, 212, 214, 216, 218, 252, 260, 428).

[0122] Figure 5B , 5C The 5D section explains operations 500b, 500c, and 500d, which, according to various embodiments, can be performed as part of method 500a for UE beam switching synchronization and link transient mitigation after UE beam switching. See also... Figure 1-5D Operations 500c and 500d can be performed by the processors (such as processors 210, 212, 214, 216, 218, 252, 260, 428) of the base stations (such as base stations 110a-110d, 200, 350, 402).

[0123] Reference Figure 5B In execution box 506 ( Figure 5A Following the operation, in block 520, the processor may allocate resources for the CSI reference signal (RS) during the UE beam switching time slot or during the next available downlink time slot. The means for performing the functions in block 520 may include a processor (e.g., 210, 212, 214, 216, 218, 252, 260, 428).

[0124] In block 522, the processor may transmit information about scheduling CSF to the UE, wherein the CSF is based on CSI-RS. The means for performing the functions in block 522 may include a processor (e.g., 210, 212, 214, 216, 218, 252, 260, 428) and a radio transceiver (e.g., 266).

[0125] In block 524, the processor may, starting from the UE beam switching time slot, avoid scheduling downlink data transmission to the UE until the data transmission parameters are adjusted based on the received CSF. The means for performing the operations in block 524 may include a processor (e.g., 210, 212, 214, 216, 218, 252, 260, 428) and a radio transceiver (e.g., 266).

[0126] The processor can then proceed to execute box 510 ( Figure 5A The operation is as described.

[0127] Reference Figure 5CIn execution box 506 ( Figure 5A Following the operation, in block 530, the processor may transmit information about scheduling aperiodic probe reference signals (SRS) to the UE during the UE beam switching time slot or during the next available uplink time slot. The means for performing the functions in block 530 may include a processor (e.g., 210, 212, 214, 216, 218, 252, 260, 428) and a radio transceiver (e.g., 266).

[0128] In block 532, the processor can receive SRS from the UE. The means for performing the functions in block 532 may include a processor (e.g., 210, 212, 214, 216, 218, 252, 260, 428) and a wireless transceiver (e.g., 266).

[0129] In block 534, the processor can adjust parameters based on SRS for uplink data transmission from the UE on the second UE beam obtained after UE beam switching. The means for performing the functions in block 530 may include a processor (e.g., 210, 212, 214, 216, 218, 252, 260, 428).

[0130] In block 536, the processor may avoid scheduling uplink data transmission from the UE from the UE beam switching time slot until after adjusting the parameters for uplink data transmission from the UE on the second UE beam. The means for performing the functions in block 536 may include a processor (e.g., 210, 212, 214, 216, 218, 252, 260, 428).

[0131] The processor can then proceed to execute box 510 ( Figure 5A The operation is as described.

[0132] refer to Figure 5D In execution box 506 ( Figure 5A Following the operation, in block 540, the processor may transmit information to the UE during the UE beam switching time slot or during the next available downlink time slot to schedule the transmission of the aperiodic tracking reference signal (TRS), enabling the UE to refine the estimation of the channel characteristics associated with the serving beam acquired after the UE beam switching. The means for performing the functions in block 540 may include a processor (e.g., 210, 212, 214, 216, 218, 252, 260, 428) and a radio transceiver (e.g., 266).

[0133] In block 542, the processor can transmit aperiodic TRS to the UE based on scheduling information. The means for performing the functions in block 540 may include a processor (e.g., 210, 212, 214, 216, 218, 252, 260, 428) and a wireless transceiver (e.g., 266).

[0134] Processor then executable box 510 ( Figure 5A The operation is as described.

[0135] Figure 6A This is a flowchart illustrating method 600a, executed by the UE's processor according to various embodiments, for UE beam switching synchronization and link transient mitigation after UE beam switching. (Refer to...) Figure 1-6A The operation of method 600a can be performed by the processor (such as processor 210, 212, 214, 216, 218, 252, 260, 432) of the base station (such as UE 120a-120f, 200, 320, 404).

[0136] In block 601, the processor may determine that a UE beam switching is required. The means for performing the functions in block 601 may include a processor (e.g., 210, 212, 214, 216, 218, 252, 260, 432) and a wireless transceiver (e.g., 266).

[0137] In block 602, the UE may send an active notification to the base station in response to determining that a UE beam switching is required, indicating that the UE will perform a beam switching from a first UE beam to a second UE beam. The means for performing the functions in block 602 may include a processor (e.g., 210, 212, 214, 216, 218, 252, 260, 432) and a radio transceiver (e.g., 266).

[0138] In block 604, the processor can perform a beam handover from a first UE beam to a second UE beam during a UE beam handover time slot. In some embodiments, starting from the UE beam handover time slot, the UE can use the new UE beam to receive any downlink transmissions intended for the UE and having a Transport Configuration Indicator (TCI) or Quasi-Co-location (QCL) corresponding to the serving beam. The means for performing the functions in block 604 may include a processor (e.g., 210, 212, 214, 216, 218, 252, 260, 432) and a radio transceiver (e.g., 266).

[0139] In block 606, the processor may receive control information from the base station regarding the allocation of CSI-RS resources on the UE beam switching time slot for channel state information feedback (CSF) for a channel associated with the second UE beam. In some embodiments, the processor may receive the information regarding the allocation of CSI-RS resources on a first relevant time slot or a later time slot. In some embodiments, the information regarding the allocation of CSI-RS resources may indicate CSF configuration and CSF transmission time. In some embodiments, the processor may receive the information regarding the allocation of CSI-RS resources on a first available time slot after the UE beam switching time slot. In some embodiments, the processor may receive the information regarding the allocation of CSI-RS resources on a later available downlink or uplink time slot that is temporally relatively close to the UE beam switching time slot. Amenities for performing the functions in block 606 may include a processor (e.g., 210, 212, 214, 216, 218, 252, 260, 432) and a radio transceiver (e.g., 266).

[0140] In block 608, the processor can use a second UE beam to receive an aperiodic channel state information reference signal (CSI-RS) from the base station. The means for performing the functions in block 608 may include a processor (e.g., 210, 212, 214, 216, 218, 252, 260, 432) and a radio transceiver (e.g., 266).

[0141] In block 610, the processor may determine a CSF, including information about the channel associated with the second UE beam, based on CSI-RS. Means for performing the functions in block 610 may include a processor (e.g., 210, 212, 214, 216, 218, 252, 260, 432).

[0142] In block 612, the processor can use the allocated CSI-RS resources to transmit CSF to the base station. In some embodiments, the processor can transmit CSF using CSF configuration during CSF transmission time. The means for performing the functions in block 612 may include a processor (e.g., 210, 212, 214, 216, 218, 252, 260, 432) and a radio transceiver (e.g., 266).

[0143] In block 614, the processor may receive instructions from the base station to adjust data communication parameters based on the transmitted CSF to align with the serving beam obtained using the second UE beam. The means for performing the functions in block 614 may include a processor (e.g., 210, 212, 214, 216, 218, 252, 260, 432) and a radio transceiver (e.g., 266).

[0144] Figure 6B and6C Operations 600b and 600c, according to various embodiments, can be performed by the UE's processor as part of a method 600a for UE beam switching synchronization and post-UE beam switching link transient mitigation. See also... Figure 1-6C Operations 600b and 600c can be performed by the processors of the UE (such as UE 120a-120f, 200, 320, 404) (such as processors 210, 212, 214, 216, 218, 252, 260, 432).

[0145] Reference Figure 6B In execution box 614 ( Figure 6A Following the operation, in block 620, the processor may receive information from the base station regarding the scheduling of aperiodic probe reference signal (SRS) transmissions during the UE beam switching time slot or during the next available uplink time slot. The means for performing the functions in block 620 may include a processor (e.g., 210, 212, 214, 216, 218, 252, 260, 432).

[0146] In block 622, the processor may transmit SRS to the base station. Means for performing the functions in block 622 may include a processor (e.g., 210, 212, 214, 216, 218, 252, 260, 432) and a wireless transceiver (e.g., 266).

[0147] In block 624, the processor may receive instructions from the base station to adjust data communication parameters for uplink data transmission on the second UE beam based on SRS. The means for performing the functions in block 624 may include a processor (e.g., 210, 212, 214, 216, 218, 252, 260, 432) and a radio transceiver (e.g., 266).

[0148] Reference Figure 6C In execution box 614 ( Figure 6A Following the operation, in block 630, the processor may receive information about the scheduling aperiodic tracking reference signal (TRS) from the base station during the UE beam switching time slot or during the next available downlink time slot. The means for performing the functions in block 630 may include a processor (e.g., 210, 212, 214, 216, 218, 252, 260, 432) and a radio transceiver (e.g., 266).

[0149] In block 632, the processor can receive the TRS based on information about scheduling the aperiodic TRS. The means for performing the functions in block 632 may include a processor (e.g., 210, 212, 214, 216, 218, 252, 260, 432) and a wireless transceiver (e.g., 266).

[0150] In block 634, the processor can refine the estimation of the channel characteristics associated with the service beam obtained after the UE beam handover to the second UE beam. The means for performing the functions in block 634 may include a processor (e.g., 210, 212, 214, 216, 218, 252, 260, 432) and a radio transceiver (e.g., 266).

[0151] Figure 7 This is a component block diagram of a base station computing device applicable to various embodiments. Such a base station computing device (e.g., base stations 110a-110d, 350, 402) may include at least Figure 7 The components explained in the text. See also... Figure 1-7 The base station computing device 700 may include a processor 701 coupled to volatile memory 702 and mass non-volatile memory (such as a disk drive 708). The base station computing device 700 may also include peripheral memory access devices 706 coupled to the processor 701, such as floppy disk drives, CD drives, or digital video disc (DVD) drives. The base station computing device 700 may also include a network access port 704 (or interface) coupled to the processor 701 for establishing data connections to networks (such as the Internet or local area networks coupled to other system computers and servers). The base station computing device 700 may include one or more antennas 707 for transmitting and receiving electromagnetic radiation, which may be connected to a wireless communication link. The base station computing device 700 may include additional access ports for coupling to peripheral devices, external memory, or other devices, such as USB, FireWire, Thunderbolt, etc.

[0152] Figure 8 This is a component block diagram of the UE 800 applicable to various embodiments. (Refer to...) Figure 1-8 Various embodiments can be implemented on a wide variety of UE 800 (e.g., UE 120a-120e, 200, 320, 404), examples of which are shown in Figure 8The UE 800 is described in the form of a smartphone. It may include a first SOC 202 (e.g., an SOC-CPU) coupled to a second SOC 204 (e.g., a 5G-capable SOC). The first and second SOCs 202, 204 may be coupled to internal memory 816, a display 812, and a speaker 814. Additionally, the UE 800 may include an antenna 804 for transmitting and receiving electromagnetic radiation, which may be connected to a wireless transceiver 266 coupled to one or more processors in the first and / or second SOCs 202, 204. The UE 800 may include menu selection buttons or a joystick switch 820 for receiving user input.

[0153] UE 800 may include a voice encoding / decoding (CODEC) circuit 810 that digitizes sound received from a microphone into data packets suitable for wireless transmission and decodes the received voice data packets to generate an analog signal for use with a speaker to produce sound. One or more of the processors in the first and second SOCs 202, 204, the wireless transceiver 266, and the CODEC 810 may include digital signal processor (DSP) circuitry (not shown separately).

[0154] The processors of the base station computing device 700 and UE 800 can be any programmable microprocessor, microcomputer, or one or more processor chips that can be configured via software instructions (applications) to perform a variety of functions, including some of the functions described below. In some UEs, multiple processors may be provided (such as one processor within SOC 204 dedicated to wireless communication functions and another processor within SOC 202 dedicated to running other applications). Software applications can be stored in memories 702 and 816, and then accessed and loaded into the processor. The processor may include internal memory sufficient to store application software instructions.

[0155] The following paragraphs describe various implementation examples. While some of the following implementation examples are described as example methods, further example implementations may include: example methods discussed in the following paragraphs implemented by a base station or UE, the base station or UE including a processor configured with processor-executable instructions to perform the operations of the methods of the following implementation examples; example methods discussed in the following paragraphs implemented by a base station or UE, the UE including means for performing the functions of the methods of the following implementation examples; and example methods discussed in the following paragraphs may be implemented as a non-transient processor-readable storage medium storing processor-executable instructions configured to cause a processor of a base station or UE to perform the operations of the methods of the following implementation examples.

[0156] Example 1. A method executed by a processor of a base station for UE beam handover synchronization and link transient mitigation after UE beam handover, comprising: receiving from the UE an active notification that the UE will perform a beam handover from a first UE beam to a second UE beam; determining, based on the received notification, a UE beam handover time slot on which the UE will perform the beam handover; performing link transient mitigation operations from the UE beam handover time slot for communication with the UE on the serving beam; receiving from the UE a CSF for a channel associated with the second UE beam; and adjusting data communication parameters based on the received CSF to align with the channel associated with the second UE beam.

[0157] Example 2. The method of Example 1 further includes: after receiving the CSF from the UE, performing a stop link transient mitigation operation for communication with the UE on the serving beam.

[0158] Example 3. A method as in either Example 1 or 2, wherein performing link transient mitigation operations for communication with the UE on the serving beam during the UE beam switching time slot includes: reducing the MCS for communication with the UE.

[0159] Example 4. A method as in either Example 1 or 2, wherein performing link transient mitigation operations for communication with the UE on the serving beam during the UE beam switching time slot includes: increasing the MCS margin of the external link adaptation loop for communication with the UE.

[0160] Example 5. A method as in either Example 1 or 2, wherein performing link transient mitigation operations for communication with the UE on the serving beam during the UE beam switching time slot includes: using single-layer transmission for communication with the UE.

[0161] Example 6. A method as in either Example 1 or 2, wherein performing link transient mitigation operations for communication with the UE on the serving beam from the UE beam switching time slot includes: performing link transient mitigation operations for communication with the UE until data transmission parameters are adjusted based on the received CSF or based on the received SRS associated with the channel obtained using the second UE beam.

[0162] Example 7. The method of any of Examples 1-6 further includes: allocating resources for CSI-RS during a UE beam switching time slot or during the next available downlink time slot; and transmitting information to the UE regarding the scheduling of CSF, wherein the CSF is based on CSI-RS.

[0163] Example 8. As in Example 7, adjusting data communication parameters based on the received CSF to align with the channel associated with the second UE beam includes: avoiding scheduling downlink data transmission to the UE from the UE beam switching time slot until the data transmission parameters are adjusted based on the received CSF.

[0164] Example 9. The method of any of Examples 1-8 further includes: transmitting information to the UE during a UE beam switching time slot or during the next available uplink time slot; and receiving SRS from the UE.

[0165] Example 10. The method of Example 9 further includes: adjusting parameters for uplink data transmission from the UE on the second UE beam obtained after UE beam switching based on SRS; and avoiding scheduling uplink data transmission from the UE from the UE beam switching time slot until after adjusting the parameters for uplink data transmission from the UE on the second UE beam.

[0166] Example 11. The method of any of Examples 1-10 further includes: transmitting information to the UE during a UE beam switching time slot or during the next available downlink time slot to enable the UE to refine the estimation of channel characteristics associated with the serving beam obtained after the UE beam switching; and transmitting the aperiodic TRS to the UE according to the scheduling information.

[0167] Example 12. A method as in any of Examples 1-11, wherein determining the UE beam-switching time slot on which the UE will perform a beam-switching based on a received notification includes: determining the UE beam-switching time slot based on the time slot in which the base station receives a notification regarding the UE's intention to perform a beam-switching and a time slot offset.

[0168] Example 13. The method of any of Examples 1-12 further includes: performing a P2 beam management procedure for beam refinement of the serving base station beam after a UE beam handover to a second UE beam and starting from the UE beam handover time slot.

[0169] Example 14. A method executed by a processor of a UE for UE beam switching synchronization and link transient mitigation after UE beam switching, comprising: determining that a UE beam switching is required; in response to determining that a UE beam switching is required, sending an active notification to a base station regarding that the UE will perform a beam switching from a first UE beam to a second UE beam; performing the beam switching from the first UE beam to the second UE beam in a UE beam switching time slot; receiving from the base station control information allocating CSI-RS resources in the UE beam switching time slot for a CSF for a channel associated with the second UE beam; receiving a non-periodic CSI-RS from the base station using the second UE beam; determining a CSF including information about the channel associated with the second UE beam based on the CSI-RS; transmitting the CSF to the base station using the allocated CSI-RS resources; and receiving from the base station an instruction to adjust data communication parameters at least in part based on the transmitted CSF to align with the channel associated with the second UE beam.

[0170] Example 15. The method of Example 14 further includes: receiving information from the base station during a UE beam switching time slot or during the next available uplink time slot; transmitting the SRS to the base station; and receiving from the base station instructions for adjusting data communication parameters for uplink data transmission on the second UE beam based on the SRS.

[0171] Example 16. The method of any of Examples 14 or 15 further includes: receiving information from the base station during a UE beam switching time slot or during the next available downlink time slot; receiving the TRS based on the information of the scheduled aperiodic TRS; and refining the estimation of channel characteristics of the channel associated with the serving beam obtained after the UE beam switching to the second UE beam.

[0172] As used herein, the terms “component,” “module,” “system,” and similar terms are intended to include computer-related entities such as, but not limited to, hardware, firmware, combinations of hardware and software, software, or software in execution configured to perform a particular operation or function. For example, a component can be, but is not limited to, a process running on a processor, a processor, an object, an executable, a thread of execution, a program, or a computer. By way of explanation, both an application running on a UE and the UE itself can be referred to as a component. One or more components may reside within a process or a thread of execution, and components may be localized on a single processor or core or distributed across two or more processors or cores. Furthermore, these components may execute from various non-transient computer-readable media on which various instructions or data structures are stored. Components may communicate via local and / or remote processes, function or procedure calls, electronic signals, data packets, memory read / write, and other known network, computer, processor, or process-related communication methods.

[0173] Several different cellular and mobile communication services and standards are available and envisioned for the future, all of which are feasible and benefit from various implementations. These services and standards include, for example, the 3rd Generation Partnership Project (3GPP), Long Term Evolution (LTE) systems, 3rd generation wireless mobile communication technology (3G), 4th generation wireless mobile communication technology (4G), 5th generation wireless mobile communication technology (5G) and subsequent 3GPP technologies, GSM, Universal Mobile Telecommunications System (UMTS), 3GSM, Universal Packet Radio Service (GPRS), Code Division Multiple Access (CDMA) systems (e.g., cdmaOne, CDMA1020TM), Enhanced Data Rate GSM Evolution (EDGE), Advanced Mobile Phone Systems (AMPS), Digital AMPS (IS-136 / TDMA), Evolved Data Optimized (EV-DO), Digital Enhanced Cordless Telecommunications (DECT), Global Interoperability for Microwave Access (WiMAX), Wireless Local Area Networks (WLAN), Wi-Fi Protected Access I and II (WPA, WPA2), and Integrated Digital Enhanced Network (iDEN). Each of these technologies relates to the transmission and reception of, for example, voice, data, signaling, and / or content messages. It should be understood that any references to terms and / or technical details relating to individual telecommunications standards or technologies are for illustrative purposes only and are not intended to limit the scope of the claims to a particular communication system or technology, unless specifically stated in the language of the claims.

[0174] The various embodiments illustrated and described are provided merely as examples illustrating the various features of the claims. However, the features shown and described for any given embodiment are not necessarily limited to the associated embodiment and may be used in conjunction with or combined with other illustrated and described embodiments. Furthermore, the claims are not intended to be limited to any single example embodiment. For example, one or more of methods and operations 500a, 500b, 500c, 500d, 600a, 600b, and 600c may replace or combine one or more of methods and operations 500a, 500b, 500c, 500d, 600a, 600b, and 600c.

[0175] The foregoing method descriptions and process flow diagrams are provided as illustrative examples only and are not intended to require or imply that the operations of the various embodiments must be performed in the given order. As those skilled in the art will appreciate, the order of operations in the foregoing embodiments can be performed in any order. Terms such as “afterward,” “following,” and “next” are not intended to limit the order of operations; these terms are used to guide the reader through the description of the method. Furthermore, any reference to a singular claim element (e.g., references using the articles “a,” “some,” or “the”) should not be construed as limiting that element to the singular.

[0176] The various illustrative logic blocks, modules, components, circuits, and algorithmic operations described in conjunction with the embodiments disclosed herein can be implemented as electronic hardware, computer software, or a combination of both. To clearly illustrate this interchangeability between hardware and software, the various illustrative components, blocks, modules, circuits, and operations are described above in a generalized manner in terms of their functionality. Whether such functionality is implemented as hardware or software depends on the specific application and the design constraints imposed on the overall system. Those skilled in the art may implement the described functionality in different ways for each specific application, but such implementation decisions should not be construed as causing a departure from the scope of the claims.

[0177] The hardware used to implement the various illustrative logics, logic blocks, modules, and circuits described in conjunction with the embodiments disclosed herein may be implemented or executed by a general-purpose processor, digital signal processor (DSP), application-specific integrated circuit (ASIC), field-programmable gate array (FPGA) or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof, designed to perform the functions described herein. The general-purpose processor may be a microprocessor, but in alternatives, the processor may be any conventional processor, controller, microcontroller, or state machine. The processor may also be implemented as a combination of receiver intelligent objects, such as a combination of a DSP and a microprocessor, multiple microprocessors, one or more microprocessors cooperating with a DSP core, or any other such configuration. Alternatively, some operations or methods may be performed by a circuit system dedicated to a given function.

[0178] In one or more embodiments, the described functionality may be implemented in hardware, software, firmware, or any combination thereof. If implemented in software, such functionality may be stored as one or more instructions or code on a non-transient computer-readable storage medium or a non-transient processor-readable storage medium. The operation of the methods or algorithms disclosed herein may be implemented in a processor-executable software module or processor-executable instructions, which may reside on a non-transient computer-readable or processor-readable storage medium. A non-transient computer-readable or processor-readable storage medium may be any storage medium accessible to a computer or processor. By way of example and not limitation, such a non-transient computer-readable or processor-readable storage medium may include RAM, ROM, EEPROM, flash memory, CD-ROM or other optical disk storage, magnetic disk storage or other magnetic storage smart objects, or any other medium that can be used to store desired program code in the form of instructions or data structures and is accessible to a computer. As used herein, disk and disc include compact discs (CDs), laser discs, optical discs, digital multi-purpose discs (DVDs), floppy disks, and Blu-ray discs. Disks typically reproduce data magnetically, while discs reproduce data optically using lasers. Combinations of these are also included within the scope of non-transient computer-readable and processor-readable media. Furthermore, the operation of a method or algorithm may reside as a piece of code and / or instructions, or any combination or set of codes and / or instructions, on a non-transient processor-readable and / or computer-readable storage medium that can be incorporated into a computer program product.

[0179] The prior description of the disclosed embodiments is intended to enable any person skilled in the art to make or use these claims. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein can be applied to other embodiments without departing from the scope of the claims. Thus, this disclosure is not intended to be limited to the embodiments shown herein, but should be accorded the broadest scope consistent with the appended claims and the principles and novel features disclosed herein.

Claims

1. A method performed by a processor of a base station for user equipment (UE) beam switch synchronization and UE beam switch post-link transient mitigation, comprising: receiving an active notification from a UE that the UE will perform a beam switch from a first UE beam to a second UE beam; determining, based on the received notification, a UE beam switch time slot on which the UE will perform the beam switch; performing, from the UE beam switch time slot, a link transient mitigation operation for communications with the UE on a serving beam; receiving, from the UE, channel state information feedback (CSF) for a channel associated with the second UE beam; and adjusting, based on the received CSF, data communication parameters to align with the channel associated with the second UE beam. stopping, after receiving the CSF from the UE, performance of the link transient mitigation operation for communications with the UE on the serving beam.

2. The method of claim 1, further comprising: performing, from the UE beam switch time slot, the link transient mitigation operation for communications with the UE on the serving beam comprises reducing a modulation and coding scheme (MCS) for communications with the UE.

3. The method of claim 1, wherein, performing, from the UE beam switch time slot, the link transient mitigation operation for communications with the UE on the serving beam comprises increasing an MCS margin of an outer link adaptation loop for communications with the UE.

4. The method of claim 1, wherein, performing, from the UE beam switch time slot, the link transient mitigation operation for communications with the UE on the serving beam comprises using a single layer transmission for communications with the UE.

5. The method of claim 1, wherein, performing, from the UE beam switch time slot, the link transient mitigation operation for communications with the UE on the serving beam comprises performing the link transient mitigation operation for communications with the UE until the data transmission parameters are adjusted based on the received CSF or based on a received SRS associated with the channel obtained with the second UE beam.

6. The method of claim 1, wherein, 7. The method of claim 1, further comprising: allocating resources for a channel state indicator-reference signal (CSI-RS) during the UE beam switch time slot or during a next available downlink time slot; and transmitting, to the UE, information scheduling the CSF, wherein the CSF is based on the CSI-RS. adjusting, based on the received CSF, data communication parameters to align with the channel associated with the second UE beam comprises refraining from scheduling downlink data transmissions to the UE from the UE beam switch time slot until the data transmission parameters are adjusted based on the received CSF.

9. The method of claim 1, further comprising:

8. The method of claim 7, wherein, transmitting, to the UE, information scheduling aperiodic sounding reference signal (SRS) transmission during the UE beam switch time slot or during a next available uplink time slot; and receiving, from the UE, the SRS.

10. The method of claim 9, further comprising: adjusting, based on the SRS, parameters for uplink data transmissions from the UE on the second UE beam obtained after the UE beam switch; and ​ ​ ​ ​ avoid scheduling uplink data transmissions from the UE until after adjusting the parameters for the uplink data transmissions from the UE on the second UE beam.

11. The method of claim 1, further comprising: transmitting, to the UE during the UE beam switch time slot or during a next available downlink time slot, information scheduling an aperiodic tracking reference signal (TRS) transmission to enable the UE to refine an estimate of a channel characteristic of the channel associated with the serving beam obtained after the UE beam switch; and transmitting the aperiodic TRS to the UE in accordance with the scheduling information.

12. The method of claim 1, wherein, determining the UE beam switch time slot in which the UE will perform the beam switch based on a time slot and a time slot offset in which the base station received the notification that the UE will perform a beam switch.

13. The method of claim 1, further comprising: performing, after the UE beam switch to the second UE beam and starting from the UE beam switch time slot, a P2 beam management procedure for beam refinement of a serving base station beam.

14. A method performed by a processor of a user equipment (UE) for UE beam switch synchronization and post-UE beam switch link transient mitigation, comprising: determining that a UE beam switch is needed; sending an active notification to a base station that the UE will perform a beam switch from a first UE beam to a second UE beam in response to determining that a UE beam switch is needed; performing the beam switch from the first UE beam to the second UE beam on a UE beam switch time slot; receiving, from the base station, control information allocating channel state information reference signal (CSI-RS) resources on the UE beam switch time slot for channel state information feedback (CSF) for a channel associated with the second UE beam; receiving, from the base station, an aperiodic CSI-RS using the second UE beam; determining the CSF including information about the channel associated with the second UE beam based on the CSI-RS; transmitting the CSF to the base station using the allocated CSI-RS resources; and receiving, from the base station, instructions to adjust data communication parameters based at least in part on the transmitted CSF to align with the channel associated with the second UE beam.

15. The method of claim 14, further comprising: receiving, from the base station, information scheduling an aperiodic sounding reference signal (SRS) transmission during the UE beam switch time slot or during a next available uplink time slot; and transmitting the SRS to the base station; and receiving, from the base station, instructions to adjust data communication parameters for uplink data transmissions on the second UE beam based on the SRS.

16. The method of claim 14, further comprising: receiving, from the base station, information scheduling an aperiodic tracking reference signal (TRS) during the UE beam switch time slot or during a next available downlink time slot; ​ ​ ​ receiving the TRS in accordance with the information scheduling the aperiodic TRS; and refining an estimate of a channel property of a channel associated with a serving beam obtained after the UE beam switch to the second UE beam.

17. A base station, comprising: a processor configured with processor-executable instructions to perform operations comprising: receiving an active notification from a user equipment (UE) that the UE will perform a beam switch from a first UE beam to a second UE beam; determining, based on the received notification, a UE beam switch time slot on which the UE will perform the beam switch; performing, from the UE beam switch time slot, a link transient mitigation operation for communication with the UE on a serving beam; receiving, from the UE, channel state information feedback (CSF) for a channel associated with the second UE beam; and adjusting, based on the received CSF, a data communication parameter to align with the channel associated with the second UE beam.

18. The base station of claim 17, wherein, the processor is configured with processor-executable instructions to perform operations further comprising, after receiving the CSF from the UE, ceasing performance of the link transient mitigation operation for communication with the UE on the serving beam.

19. The base station of claim 17, wherein, the processor is configured with processor-executable instructions to perform operations such that performing, from the UE beam switch time slot, the link transient mitigation operation for communication with the UE on the serving beam comprises decreasing a modulation and coding scheme (MCS) for communication with the UE.

20. The base station of claim 17, wherein, the processor is configured with processor-executable instructions to perform operations such that performing, from the UE beam switch time slot, the link transient mitigation operation for communication with the UE on the serving beam comprises increasing an MCS margin of an outer link adaptation loop for communication with the UE.

21. The base station of claim 17, wherein, the processor is configured with processor-executable instructions to perform operations such that performing, from the UE beam switch time slot, the link transient mitigation operation for communication with the UE on the serving beam comprises using a single layer transmission for communication with the UE.

22. The base station of claim 17, wherein, the processor is configured with processor-executable instructions to perform operations such that performing, from the UE beam switch time slot, the link transient mitigation operation for communication with the UE on the serving beam comprises performing the link transient mitigation operation for communication with the UE until the data communication parameter is adjusted based on the received CSF or based on a received SRS associated with the channel obtained with the second UE beam.

23. The base station of claim 17, wherein, the processor is configured with processor-executable instructions to perform operations further comprising: allocating resources for a CSI-reference signal (RS) during the UE beam switch time slot or during a next available downlink time slot; and transmitting, to the UE, information scheduling the CSF, wherein the CSF is based on the CSI-RS. ​ 24. The base station of claim 23, wherein, The processor is configured with processor-executable instructions to perform operations such that adjusting data communication parameters to align with the channel associated with the second UE beam based on the received CSF adjustment data comprises refraining from scheduling downlink data transmissions to the UE from the UE beam switch time slot until the data transmission parameters are adjusted based on the received CSF.

25. The base station of claim 17, wherein, The processor is configured with processor-executable instructions to perform operations further comprising: transmitting information to the UE to schedule an aperiodic sounding reference signal (SRS) transmission during the UE beam switch time slot or during a next available uplink time slot; and receiving the SRS from the UE.

26. The base station of claim 25, wherein, The processor is configured with processor-executable instructions to perform operations further comprising: adjusting parameters for uplink data transmissions from the UE on the second UE beam obtained after the UE beam switch based on the SRS; and refraining from scheduling uplink data transmissions from the UE from the UE beam switch time slot until after adjusting the parameters for the uplink data transmissions from the UE on the second UE beam.

27. The base station of claim 17, wherein, The processor is configured with processor-executable instructions to perform operations further comprising: transmitting information to the UE to schedule an aperiodic tracking reference signal (TRS) transmission during the UE beam switch time slot or during a next available downlink time slot to enable the UE to refine an estimate of channel characteristics of the channel associated with the serving beam obtained after the UE beam switch; and transmitting the aperiodic TRS to the UE in accordance with the scheduling information.

28. The base station of claim 17, wherein, The processor is configured with processor-executable instructions to perform operations such that determining the UE beam switch time slot on which the UE will perform the beam switch based on the received notification comprises determining the UE beam switch time slot based on a time slot and a time slot offset in which the base station receives the notification that the UE will perform a beam switch.

29. The base station of claim 17, wherein, The processor is configured with processor-executable instructions to perform operations further comprising performing a P2 beam management procedure for beam refinement of a serving base station beam after the UE beam switch to the second UE beam and from the UE beam switch time slot.

30. A user equipment (UE), comprising: a processor configured with processor-executable instructions to perform operations comprising: determining that a UE beam switch is needed; sending an active notification to a base station that the UE will perform a beam switch from a first UE beam to a second UE beam in response to determining that a UE beam switch is needed; performing the beam switch from the first UE beam to the second UE beam on a UE beam switch time slot; receiving control information from the base station that allocates CSI-RS resources on the UE beam switch time slot for channel state information feedback (CSF) for a channel associated with the second UE beam; receiving, from the base station, aperiodic channel state information reference signal (CSI-RS) using the second UE beam; determining, based on the CSI-RS, the CSF including information about the channel associated with the second UE beam; transmitting, to the base station, the CSF using the allocated CSI-RS resource; and receiving, from the base station, an instruction to adjust a data communication parameter to align with the channel associated with the second UE beam based at least in part on the transmitted CSF.

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