Beam switching upon reception of negative acknowledgement

Abstract

Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a user equipment (UE) can transmit a measurement report based at least in part on a set of measurements of one or more reference signals received using a set of candidate beams; transmit a negative acknowledgement for a downlink transmission scheduled for one or more beams of the set of candidate beams; and monitor one or more new beams of the set of candidate beams for a retransmission of the downlink transmission. Numerous other aspects are provided.

Description

[0001] Cross-reference to related applications

[0002] This patent application claims priority to Greek patent application No. 20200100111, filed on February 28, 2020, entitled “BEAM SWITCHING UPON NEGATIVE ACKNOWLEDGEMENT RECEPTION”, assigned to the assignee of this application. The disclosure of that earlier application is considered part of this patent application and is incorporated herein by reference.

[0003] open field

[0004] Various aspects of this disclosure generally relate to wireless communication, and to techniques and apparatus for beam switching based at least in part on receiving a negative acknowledgment (NACK).

[0005] background

[0006] Wireless communication systems are widely deployed to provide a variety of telecommunications services such as telephone, video, data, messaging, and broadcasting. Typical wireless communication systems employ multiple access technologies that can support communication with multiple users by sharing available system resources (e.g., bandwidth, transmit power). Examples of such multiple access technologies include Code Division Multiple Access (CDMA) systems, Time Division Multiple Access (TDMA) systems, Frequency Division Multiple Access (FDMA) systems, Orthogonal Frequency Division Multiple Access (OFDMA) systems, Single Carrier Frequency Division Multiple Access (SC-FDMA) systems, Time Division Synchronous Code Division Multiple Access (TD-SCDMA) systems, and Long Term Evolution (LTE). LTE / LTE-Advanced is an enhancement set of the Universal Mobile Telecommunications System (UMTS) mobile standard issued by the 3rd Generation Partnership Project (3GPP).

[0007] A wireless network may include several base stations (BSs) capable of supporting communication between several user equipments (UEs). UEs can communicate with the BS via downlink and uplink. The downlink (or forward link) refers to the communication link from the BS to the UE, while the uplink (or reverse link) refers to the communication link from the UE to the BS. As will be described in more detail herein, the BS may be referred to as a B-node, gNB, access point (AP), radio headend, transmit / receive point (TRP), new radio (NR) BS, 5G B-node, etc.

[0008] The above multiple access technologies have been adopted in various telecommunications standards to provide a common protocol enabling different user equipment to communicate at the city, country, region, and even global levels. NR (which can also be referred to as 5G) is an enhancement set of the LTE mobile standard issued by 3GPP. NR is designed to better support mobile broadband Internet access by using Orthogonal Frequency Division Multiplexing (OFDM) with a Cyclic Prefix (CP) (CP-OFDM) on the downlink (DL), and using CP-OFDM and / or SC-FDM (e.g., also known as Discrete Fourier Transform Extended OFDM (DFT-s-OFDM)) on the uplink (UL), as well as supporting beamforming, multiple-input multiple-output (MIMO) antenna technologies and carrier aggregation to improve spectral efficiency, reduce costs, improve service, utilize new spectrum, and better integrate with other open standards. Further improvements to LTE, NR, and other radio access technologies remain useful as the demand for mobile broadband access continues to grow.

[0009] Overview

[0010] In some aspects, a wireless communication method performed by a user equipment (UE) may include: transmitting a measurement report based at least in part on a set of measurements of one or more reference signals received using a candidate beam set; transmitting a negative acknowledgment (NACK) for a downlink transmission scheduled for one or more beams in the candidate beam set; and monitoring one or more new beams in the candidate beam set to look for retransmissions of the downlink transmission.

[0011] In some aspects, a wireless communication method performed by a base station may include: receiving a measurement report from a UE indicating a measurement set of one or more reference signals received using a candidate beam set; identifying a NACK feedback associated with a downlink transmission transmitted via one or more beams in the candidate beam set; and retransmitting the downlink transmission via one or more new beams in the candidate beam set.

[0012] In some aspects, a UE for wireless communication may include a memory and one or more processors operatively coupled to the memory. The memory and the one or more processors may be configured to: transmit measurement reports based at least in part on a set of measurements of one or more reference signals received using a candidate beam set; transmit NACKs for downlink transmissions scheduled for one or more beams in the candidate beam set; and monitor one or more new beams in the candidate beam set to look for retransmissions of the downlink transmission.

[0013] In some aspects, a base station for wireless communication may include a memory and one or more processors operatively coupled to the memory. The memory and the one or more processors may be configured to: receive a measurement report from a UE indicating a measurement set of one or more reference signals received using a candidate beam set; identify NACK feedback associated with a downlink transmission transmitted via one or more beams in the candidate beam set; and transmit a retransmission of the downlink transmission via one or more new beams in the candidate beam set.

[0014] In some aspects, a non-transient computer-readable medium may store one or more instructions for wireless communication. When executed by one or more processors of the UE, the one or more instructions may cause the processors to: transmit a measurement report based at least in part on a set of measurements of one or more reference signals received using a candidate beam set; transmit a NACK for a downlink transmission scheduled for one or more beams in the candidate beam set; and monitor one or more new beams in the candidate beam set to seek retransmissions of the downlink transmission.

[0015] In some aspects, a non-transient computer-readable medium may store one or more instructions for wireless communication. When executed by one or more processors of a base station, the one or more instructions may cause the processors to: receive a measurement report from a UE indicating a measurement set of one or more reference signals received using a candidate beam set; identify a NACK feedback associated with a downlink transmission transmitted via one or more beams in the candidate beam set; and retransmit the downlink transmission via one or more new beams in the candidate beam set.

[0016] In some aspects, an apparatus for wireless communication may include: means for transmitting a measurement report based at least in part on a set of measurements of one or more reference signals received using a set of candidate beams; means for transmitting a NACK for a downlink transmission scheduled for one or more beams in the set of candidate beams; and means for monitoring one or more new beams in the set of candidate beams to look for retransmissions of the downlink transmission.

[0017] In some aspects, an apparatus for wireless communication may include: means for receiving a measurement report from a UE, the measurement report indicating a measurement set of one or more reference signals received using a candidate beam set; means for identifying a NACK feedback associated with a downlink transmission transmitted via one or more beams in the candidate beam set; and means for transmitting a retransmission of the downlink transmission via one or more new beams in the candidate beam set.

[0018] The aspects generally include, as substantially described herein with reference to the accompanying drawings and description, methods, apparatus, systems, computer program products, non-transient computer-readable media, user equipment, base stations, wireless communication equipment, and / or processing systems.

[0019] The foregoing has broadly outlined the features and technical advantages of the examples according to this disclosure in an effort to facilitate a better understanding of the following detailed description. Additional features and advantages will be described thereafter. The disclosed concepts and specific examples can be readily used as the basis for modifications or the design of other structures for implementing the same purposes as this disclosure. Such equivalent constructions do not depart from the scope of the appended claims. The characteristics of the concepts disclosed herein, in both their organization and manner of operation, and their associated advantages, will be better understood by considering the following description in conjunction with the accompanying drawings. Each drawing is provided for illustrative and descriptive purposes and not for defining limitations on the claims.

[0020] While aspects are described herein by way of example, those skilled in the art will understand that such aspects can be implemented in many different arrangements and scenarios. The techniques described herein can be implemented using different platform types, devices, systems, shapes, sizes, and / or package arrangements. For example, some aspects may be implemented via integrated chip embodiments or other devices based on non-modular components (e.g., end-user equipment, vehicles, communication equipment, computing devices, industrial equipment, retail / shopping equipment, medical devices, or AI-enabled devices). Aspects can be implemented in chip-level components, modular components, non-modular components, non-chip-level components, device-level components, or system-level components. Devices incorporating the described aspects and features may include additional components and features for implementing and practicing the claimed and described aspects. For example, the transmission and reception of wireless signals may include several components (e.g., hardware components including antennas, RF chains, power amplifiers, modulators, buffers, processors, interleavers, adders, or summers) for analog and digital purposes. The aspects described herein are intended to be practiced in a wide variety of devices, components, systems, distributed arrangements, or end-user equipment of various sizes, shapes, and configurations. Brief description of the attached diagram

[0022] To gain a more detailed understanding of the features described above in this disclosure, reference can be made to various aspects of the above brief overview, some of which are illustrated in the accompanying drawings. However, it should be noted that the drawings illustrate only certain typical aspects of this disclosure and should not be considered as limiting its scope, as other equivalent aspects are permissible in this description. Identical reference numerals in different drawings may identify the same or similar elements.

[0023] Figure 1This is a diagram illustrating an example of a wireless network according to this disclosure.

[0024] Figure 2 This is a diagram illustrating an example of communication between a base station and a UE in a wireless network according to this disclosure.

[0025] Figure 3 This is a diagram illustrating an example of beam switching based at least in part on the receipt of a NACK, according to this disclosure.

[0026] Figure 4 This is a diagram illustrating an example of beam switching based at least in part on the receipt of a NACK, according to this disclosure.

[0027] Figure 5 This is a diagram illustrating an example of beam switching based at least in part on the receipt of a NACK, according to this disclosure.

[0028] Figure 6 This is a diagram illustrating an example process performed by a user equipment according to this disclosure.

[0029] Figure 7 This is a diagram illustrating an example process performed by a base station according to this disclosure.

[0030] Detailed description

[0031] The various aspects of this disclosure are described more fully below with reference to the accompanying drawings. However, this disclosure may be implemented in many different forms and should not be construed as being limited to any specific structure or function given throughout this disclosure. Rather, these aspects are provided so that this disclosure will be thorough and complete, and will fully convey the scope of this disclosure to those skilled in the art. Based on the teachings herein, those skilled in the art will appreciate that the scope of this disclosure is intended to cover any aspect of this disclosure disclosed herein, whether implemented independently of or in combination with any other aspect of this disclosure. For example, any number of aspects set forth herein may be used to implement an apparatus or method of practice. Furthermore, the scope of this disclosure is intended to cover such apparatus or methods practiced using additional structures, functionalities, or structures and functionalities that complement or supplement the various aspects of this disclosure set forth herein. It should be understood that any aspect of this disclosure disclosed herein may be implemented by one or more elements of the claims.

[0032] Several aspects of a telecommunications system will now be described with reference to various devices and techniques. These devices and techniques will be described in the following detailed description and explained in the accompanying drawings by various blocks, modules, components, circuits, steps, processes, algorithms, etc. (collectively, "elements"). These elements can be implemented using hardware, software, or a combination thereof. Whether such elements are implemented as hardware or software depends on the specific application and the design constraints imposed on the overall system.

[0033] It should be noted that although the aspects are described herein using terms commonly associated with 5G or NR radio access technology (RAT), the aspects of this disclosure may be applied to other RATs, such as 3G RAT, 4G RAT, and / or RATs after 5G (e.g., 6G).

[0034] Figure 1 This is a diagram illustrating an example of a wireless network 100 according to this disclosure. The wireless network 100 may be a 5G (NR) network and / or an LTE network, etc., or may include elements thereof. The wireless network 100 may include several base stations 110 (shown as BS110a, BS 110b, BS 110c, and BS 110d) and other network entities. A base station (BS) is an entity that communicates with a user equipment (UE) and may also be referred to as an NR BS, B-node, gNB, 5G B-node (NB), access point, transmit / receive point (TRP), etc. Each BS may provide communication coverage for a specific geographic area. In 3GPP, the term "cell" may refer to the coverage area of ​​a BS and / or the BS subsystem serving that coverage area, depending on the context in which the term is used.

[0035] A BS can provide communication coverage for macrocells, picocells, femtocells, and / or another type of cell. 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 BS used for macrocells may be referred to as a macro BS. A BS used for picocells may be referred to as a pico BS. A BS used for femtocells may be referred to as a femto BS or a home BS. Figure 1 In the example shown, BS 110a can be a macro BS for macro cell 102a, BS 110b can be a pico BS for pico cell 102b, and BS 110c can be a femto BS for femto cell 102c. A BS 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.

[0036] In some respects, the cell may not be stationary, and the geographical area of ​​the cell may move depending on the location of the mobile BS. In some respects, BSs may interconnect with each other and / or interconnect to one or more other BSs or network nodes (not shown) in the wireless network 100 via various types of backhaul interfaces (such as direct physical connections or virtual networks, using any suitable transport network).

[0037] The wireless network 100 may also include a relay station. A relay station is an entity capable of receiving data transmissions from an upstream station (e.g., a BS or a UE) and transmitting those data transmissions to a downstream station (e.g., a UE or a BS). A relay station can also be a UE capable of relaying transmissions for other UEs. Figure 1 In the example shown, relay BS 110d can communicate with macro BS 110a and UE 120d to facilitate communication between BS 110a and UE 120d. A relay BS can also be referred to as a relay station, relay base station, relay, etc.

[0038] Wireless network 100 can be a heterogeneous network comprising different types of Base Stations (BSs) such as macro BSs, pico BSs, femto BSs, relay BSs, etc. These different types of BSs may have different transmit power levels, different coverage areas, and different effects on interference in wireless network 100. For example, macro BSs may have high transmit power levels (e.g., 5 to 40 watts), while pico BSs, femto BSs, and relay BSs may have lower transmit power levels (e.g., 0.1 to 2 watts).

[0039] Network controller 130 can be coupled to a set of Base Stations (BSs) and can provide coordination and control over these BSs. Network controller 130 can communicate with each BS via backhaul. These BSs can also communicate with each other directly or indirectly via wireless or wired backhaul.

[0040] UE 120 (e.g., 120a, 120b, 120c) may be distributed throughout the wireless network 100, and each UE may be stationary or mobile. UE may also be referred to as an access terminal, terminal, mobile station, subscriber unit, station, etc. UE may be a cellular phone (e.g., a smartphone), personal digital assistant (PDA), wireless modem, wireless communication device, handheld device, laptop computer, cordless phone, wireless local loop (WLL) station, tablet, camera, gaming device, netbook, smartbook, ultrabook, medical device or equipment, biometric sensor / device, wearable device (smartwatch, smart clothing, smart glasses, smart wristband, smart jewelry (e.g., smart ring, smart bracelet)), entertainment device (e.g., music or video device, or satellite radio), vehicle component or sensor, smart meter / sensor, industrial manufacturing equipment, GPS device, or any other suitable device configured to communicate via wireless or wired media.

[0041] Some UEs may be considered Machine-Type Communication (MTC) UEs, or evolved or enhanced Machine-Type Communication (eMTC) UEs. MTC and eMTC UEs include, for example, robots, drones, remote devices, sensors, instruments, monitors, and / or location tags that can communicate with a base station, another device (e.g., a remote device), or some other entity. Wireless nodes may 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 may be considered Internet of Things (IoT) devices, and / or may be implemented as NB-IoT (Narrowband Internet of Things) devices. Some UEs may be considered Customer Premises Equipment (CPE). UE120 may be included within a housing that houses components of UE120, such as processor components and / or memory components. In some aspects, the processor components and memory components may be coupled together. For example, the processor components (e.g., one or more processors) and memory components (e.g., memory) may be operatively coupled, communicatively coupled, electronically coupled, and / or electrically coupled.

[0042] Generally, any number of wireless networks can be deployed in a given geographical area. Each wireless network can support a specific RAT and can operate on one or more frequencies. A RAT may also be referred to as a radio technology, air interface, etc. A frequency may 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 wireless networks using different RATs. In some cases, NR or 5G RAT networks can be deployed.

[0043] In some respects, two or more UEs 120 (e.g., shown as UE 120a and UE 120e) may communicate directly using one or more sidelink channels (e.g., without using base station 110 as an intermediary). For example, UE 120 may communicate using peer-to-peer (P2P) communication, device-to-device (D2D) communication, vehicle-to-everything (V2X) protocols (e.g., which may include vehicle-to-vehicle (V2V) protocols or vehicle-to-infrastructure (V2I) protocols), and / or mesh networks. In this scenario, UE 120 may perform scheduling operations, resource selection operations, and / or other operations described elsewhere herein as being performed by base station 110.

[0044] Devices in the wireless network 100 can communicate using the electromagnetic spectrum, which can be subdivided into various categories, bands, channels, etc., based on frequency or wavelength. For example, devices in the wireless network 100 can communicate using an operating band with a first frequency range (FR1) and / or an operating band with a second frequency range (FR2), where the first frequency range (FR1) spans from 410 MHz to 7.125 GHz and the second frequency range (FR2) spans from 24.25 GHz to 52.6 GHz. The frequencies between FR1 and FR2 are sometimes referred to as intermediate frequency (IF) bands. Although a portion of FR1 is greater than 6 GHz, FR1 is often referred to as the "sub-6 GHz" band. Similarly, although distinct from the Extremely High Frequency (EHF) band (30 GHz–300 GHz) designated as the "millimeter wave" band by the International Telecommunication Union (ITU), FR2 is often referred to as the "millimeter wave" band. Therefore, unless otherwise stated, it should be understood that, if used herein, the terms "sub-6 GHz" and the like can broadly refer to frequencies less than 6 GHz, frequencies within FR1, and / or intermediate frequency band frequencies (e.g., greater than 7.125 GHz). Similarly, unless otherwise stated, it should be understood that, if used herein, the terms "millimeter wave" and the like can broadly refer to frequencies within the EHF band, frequencies within FR2, and / or intermediate frequency band frequencies (e.g., less than 24.25 GHz). It is conceivable that the frequencies included in FR1 and FR2 can be modified, and the techniques described herein are applicable to those modified frequency ranges.

[0045] As indicated above, Figure 1 This is provided as an example. Other examples may differ from the one provided. Figure 1 The example described.

[0046] Figure 2This is a diagram illustrating an example 200 of communication between a base station 110 and a UE 120 in a wireless network 100 according to this disclosure. The base station 110 may be equipped with T antennas 234a to 234t, while the UE 120 may be equipped with R antennas 252a to 252r, wherein generally T≥1 and R≥1.

[0047] At base station 110, transmit processor 220 can receive data destined for one or more UEs from data source 212, select one or more modulation and coding schemes (MCS) for each UE based at least in part on channel quality indicators (CQI) received from each UE, process (e.g., encode and modulate) the data for each UE based at least in part on the MCS selected for each UE, and provide data symbols for all UEs. Transmit processor 220 can also process system information (e.g., semi-static resource allocation information (SRPI)) and control information (e.g., CQI requests, grants, and / or upper-layer signaling), and provide overhead symbols and control symbols. Transmit processor 220 can also generate reference symbols for reference signals (e.g., cell-specific reference signals (CRS) or demodulation reference signals (DMRS)) and synchronization signals (e.g., primary synchronization signal (PSS) or secondary synchronization signal (SSS)). The transmit (TX) multiple-input multiple-output (MIMO) processor 230 can perform spatial processing (e.g., precoding) on ​​data symbols, control symbols, overhead symbols, and / or reference symbols, where applicable, and can provide T output symbol streams to T modulators (MODs) 232a to 232t. Each modulator 232 can process its respective output symbol stream (e.g., for OFDM) to obtain an output sample stream. Each modulator 232 can further process (e.g., convert to analog, amplify, filter, and up-convert) the output sample stream to obtain a downlink signal. The T downlink signals from modulators 232a to 232t can be transmitted via T antennas 234a to 234t, respectively.

[0048] At UE 120, antennas 252a to 252r can receive downlink signals from base station 110 and / or other base stations and can provide the received signals to demodulators (DEMODs) 254a to 254r respectively. Each demodulator 254 can condition (e.g., filter, amplify, downconvert, and digitize) the received signal to obtain an input sample. Each demodulator 254 can further process the input sample (e.g., for OFDM) to obtain received symbols. MIMO detector 256 can obtain the received symbols from all R demodulators 254a to 254r, perform MIMO detection on these received symbols where applicable, and provide detected symbols. Receiver processor 258 can process (e.g., demodulate and decode) these detected symbols, provide decoded data for UE 120 to data sink 260, and provide decoded control information and system information to controller / processor 280. The term "controller / processor" can refer to one or more controllers, one or more processors, or a combination thereof. The channel processor can determine parameters such as Reference Signal Received Power (RSRP), Received Signal Strength Indicator (RSSI), Reference Signal Received Quality (RSRQ), and / or CQI. In some respects, one or more components of the UE 120 may be included in the housing.

[0049] Network controller 130 may include communication unit 294, controller / processor 290, and memory 292. Network controller 130 may include one or more devices, such as those in the core network. Network controller 130 may communicate with base station 110 via communication unit 294.

[0050] Antennas (e.g., antennas 234a to 234t and / or antennas 252a to 252r) may include or be included within one or more antenna panels, antenna groups, antenna element assemblies, and / or antenna arrays. Antenna panels, antenna groups, antenna element assemblies, and / or antenna arrays may include one or more antenna elements. Antenna panels, antenna groups, antenna element assemblies, and / or antenna arrays may include coplanar antenna element assemblies and / or non-coplanar antenna element assemblies. Antenna panels, antenna groups, antenna element assemblies, and / or antenna arrays may include antenna elements within a single housing and / or multiple antenna elements within housings. Antenna panels, antenna groups, antenna element assemblies, and / or antenna arrays may include elements coupled to one or more transmission and / or reception components (such as...). Figure 2 One or more antenna elements (one or more components).

[0051] On the uplink, at UE 120, transmit processor 264 can receive and process data from data source 262 and control information from controller / processor 280 (e.g., reports including RSRP, RSSI, RSRQ, and / or CQI). Transmit processor 264 can also generate reference symbols for one or more reference signals. Symbols from transmit processor 264 can be pre-encoded by TX MIMO processor 266, where applicable, further processed by modulators 254a to 254r (e.g., for DFT-s-OFDM or CP-OFDM), and transmitted to base station 110. In some aspects, modulators and demodulators (e.g., MOD / DEMOD 254) of UE 120 may be included in the modem of UE 120. In some aspects, UE 120 includes a transceiver. The transceiver may include any combination of antennas 252, modulators and / or demodulators 254, MIMO detectors 256, receiver processors 258, transmitter processors 264, and / or TX MIMO processors 266. The transceiver may be used by a processor (e.g., controller / processor 280) and memory 282 to perform aspects of any of the methods described herein, for example, as referenced. Figure 3-7 As described.

[0052] At base station 110, uplink signals from UE 120 and other UEs can be received by antenna 234, processed by demodulator 232, detected by MIMO detector 236 where applicable, and further processed by receiver processor 238 to obtain decoded data and control information transmitted by UE 120. Receiver processor 238 can provide the decoded data to data sink 239 and the decoded control information to controller / processor 240. Base station 110 may include communication unit 244 and communicate with network controller 130 via communication unit 244. Base station 110 may include scheduler 246 to schedule UE 120 for downlink and / or uplink communications. In some aspects, the modulator and demodulator (e.g., MOD / DEMOD 232) of base station 110 may be included in the modem of base station 110. In some aspects, base station 110 includes a transceiver. The transceiver may include any combination of antennas 234, modulators and / or demodulators 232, MIMO detectors 236, receiver processors 238, transmitter processors 220, and / or TX MIMO processors 230. The transceiver may be used by a processor (e.g., controller / processor 240) and memory 242 to perform aspects of any of the methods described herein, for example, as referenced. Figure 3-7 As described.

[0053] The controller / processor 240 of base station 110, the controller / processor 280 of UE 120, and / or Figure 2 Any other component may perform one or more techniques associated with beam switching based at least in part on the receipt of a NACK, as described in more detail elsewhere herein. For example, the controller / processor 240 of base station 110, the controller / processor 280 of UE 120, and / or Figure 2 Any other component may execute or direct, for example Figure 6 Process 600 Figure 7 The operation of process 700 and / or other processes as described herein. Memory 242 and 282 may store data and program code for base station 110 and UE 120, respectively. In some aspects, memory 242 and / or memory 282 may include: a non-transitory computer-readable medium storing one or more instructions (e.g., code and / or program code) for wireless communication. For example, when executed by one or more processors of base station 110 and / or UE 120 (e.g., direct execution, or execution after compilation, transformation, and / or interpretation), the one or more processors, UE 120, and / or base station 110 may cause the one or more processors, UE 120, and / or base station 110 to perform or direct, for example... Figure 6 Process 600 Figure 7 The operation of process 700 and / or other processes described herein. In some aspects, the execution instructions may include run instructions, translate instructions, compile instructions, interpret instructions, etc.

[0054] In some aspects, the UE includes means for transmitting a measurement report based at least in part on a set of measurements of one or more reference signals received using a candidate beam set; means for transmitting a negative acknowledgment of a downlink transmission scheduled for one or more beams in the candidate beam set; or means for monitoring one or more new beams in the candidate beam set to find retransmissions of the downlink transmission. Means for the UE to perform the operations described herein may include, for example, one or more of antenna 252, demodulator 254, MIMO detector 256, receive processor 258, transmit processor 264, TX MIMO processor 266, modulator 254, controller / processor 280, or memory 282.

[0055] In some aspects, the UE includes means for receiving radio resource control (RRC) reconfiguration signaling, the RRC reconfiguration signaling including an indication regarding monitoring the candidate beam set to search for one or more reference signals; means for configuring the UE to monitor the candidate beam set to search for the one or more reference signals; or means for transmitting an indication regarding the UE being configured to monitor the candidate beam set to search for the one or more reference signals.

[0056] In some aspects, the UE includes means for obtaining measurements of one or more reference signals received on a set of candidate beams; or means for determining the ranking of candidate beams in the set of candidate beams based at least in part on the measurements of the one or more reference signals.

[0057] In some aspects, the UE includes means for selecting one or more beams for receiving the downlink transmission, based at least in part on a set of measurements of the one or more reference signals.

[0058] In some aspects, the UE includes means for further selecting the number of the one or more beams, at least in part, based on the configuration of the UE.

[0059] In some aspects, the UE includes means for selecting one or more new beams for monitoring retransmissions of the downlink transmission, based at least in part on a set of measurements of the one or more reference signals.

[0060] In some respects, the UE includes means for further selecting the number of the one or more new beams, at least in part, based on the configuration of the UE.

[0061] In some aspects, the UE includes means for determining whether the timing offset between transmitting a measurement report and transmitting a negative acknowledgment satisfies a timing threshold.

[0062] In some aspects, the UE includes means for receiving downlink control information messages that activate one or more new beams for monitoring retransmissions of the downlink transmission.

[0063] In some aspects, the UE includes means for monitoring the one or more new beams in the candidate beam set to look for retransmissions of the downlink transmission in the absence of an instruction from the base station to activate the one or more new beams after a negative reception of the transmission.

[0064] In some respects, the UE includes means for receiving retransmissions of the downlink transmission via at least one of the one or more new beams.

[0065] In some aspects, the UE includes means for transmitting confirmation of retransmissions of downlink transmissions received via at least one of the one or more new beams.

[0066] In some respects, the UE includes means for transmitting at least one additional message via at least one of the one or more new beams.

[0067] In some aspects, the base station includes means for receiving a measurement report from the UE, the measurement report indicating a measurement set of one or more reference signals received using a candidate beam set; means for identifying a negative acknowledgment feedback associated with a downlink transmission transmitted via one or more beams in the candidate beam set; or means for retransmitting the downlink transmission via one or more new beams in the candidate beam set. Means for the base station to perform the operations described herein may include, for example, one or more of a transmit processor 220, a TX MIMO processor 230, a modulator 232, an antenna 234, a demodulator 232, a MIMO detector 236, a receive processor 238, a controller / processor 240, a memory 242, or a scheduler 246.

[0068] In some respects, the base station includes means for performing beam sweeping using one or more new beams.

[0069] In some aspects, the base station includes means for using one or more new beams and the one or more beams to perform beam sweeping.

[0070] In some aspects, the base station includes means for transmitting RRC reconfiguration signaling including an indication of monitoring the candidate beam set to find one or more reference signals; or means for receiving an indication that the UE is configured to monitor the candidate beam set to find the one or more reference signals.

[0071] In some aspects, the base station includes means for determining the ranking of candidate beams in the candidate beam set based at least in part on a set of measurements of the one or more reference signals.

[0072] In some aspects, the base station includes means for selecting one or more beams for transmitting the downlink transmission, based at least in part on a set of measurements of the one or more reference signals.

[0073] In some respects, the base station includes means for selecting the number of the one or more beams, at least in part, based on an instruction provided to the UE.

[0074] In some aspects, the base station includes means for selecting one or more new beams for retransmitting the downlink transmission, based at least in part on a set of measurements of the one or more reference signals.

[0075] In some respects, the base station includes means for selecting the number of one or more new beams, at least in part, based on an instruction provided to the UE.

[0076] In some aspects, the base station includes means for determining that the timing offset between the timing of receiving a measurement report and the timing of a negative reception feedback satisfies a timing threshold, wherein the retransmission of the downlink transmission via the one or more new beams is based at least in part on determining that the timing offset satisfies the timing threshold.

[0077] In some aspects, the base station includes means for transmitting downlink control information messages that activate one or more new beams for monitoring retransmissions of the downlink transmission.

[0078] In some aspects, the base station includes means for retransmitting the downlink transmission via the one or more new beams without transmitting an instruction to activate the one or more new beams after a negative reception feedback has been received.

[0079] In some respects, the base station includes means for receiving confirmation of retransmissions for the downlink transmission via at least one of the one or more new beams.

[0080] In some respects, the base station includes means for transmitting at least one additional message via at least one of the one or more new beams.

[0081] In some aspects, the base station includes means for interpreting the timing of a HARQ feedback as a negative acceptance based at least in part on the absence of an acceptance during the timing of the HARQ feedback.

[0082] although Figure 2 The boxes in the diagram are interpreted as different components, but the functions described above with respect to these boxes can be implemented using a single hardware component, software component, or combination of components. For example, the functions described with respect to transmit processor 264, receive processor 258, and / or TX MIMO processor 266 can be performed by controller / processor 280 or under the control of controller / processor 280.

[0083] As indicated above, Figure 2 This is provided as an example. Other examples may differ from the one provided. Figure 2 The example described.

[0084] When a base station schedules downlink transmissions and requests HARQ feedback, the UE can monitor the downlink transmissions to attempt to receive them. If the UE receives the downlink transmission, it can send an acknowledgment (ACK) to the base station to notify it that it has received the transmission. If the UE fails to receive the downlink transmission, it can send a non-acknowledgment (NACK) to the base station to notify it that it has not received the transmission. Based at least in part on receiving a NACK, the base station can retransmit the downlink transmission, modify subsequent downlink transmissions, etc.

[0085] If a UE fails to receive a downlink transmission at least in part due to altered conditions of the beam used to transmit the downlink transmission, the UE may not receive retransmissions of the downlink transmission via the same beam. For example, if a UE fails to receive a downlink transmission at least in part due to interference, noise, etc., the UE may also fail to receive retransmissions of the downlink transmission. If the UE has multiple opportunities configured to receive downlink transmissions (e.g., using semi-persistent scheduling), the base station can use the beam through which the UE cannot receive subsequent downlink transmissions to continue transmission. The UE and / or the base station may expend computational, communication, and / or network resources to attempt to transmit and receive additional transmissions and / or recover from additional transmissions that the UE has not received.

[0086] In some aspects described herein, a base station (e.g., base station 110) may transmit one or more reference signals via a candidate beam set. A UE (e.g., UE 120) may monitor the one or more reference signals via the one or more candidate beams. The UE may obtain measurements of the one or more reference signals and generate a measurement report, at least in part, based on the measurements to identify the ranking of the candidate beam set. The UE may transmit the measurement report to the base station to identify the ranking of the candidate beam set. The UE and the base station may communicate via one or more beams in the candidate beam set.

[0087] The UE can be configured to monitor one or more new beams in the candidate beam set in response to transmitting a NACK for a downlink transmission scheduled for the one or more beams to search for a retransmission of the downlink transmission. In other words, instead of monitoring only one or more beams in the candidate beam set through which the UE has not received a downlink transmission, the UE can monitor other beams to search for a retransmission of the downlink transmission. The UE can use at least one of the one or more new beams to transmit an ACK to indicate that the UE has received a retransmission of the downlink transmission via at least one of the one or more new beams. In some aspects, the UE and the base station can continue communication via at least one of the one or more new beams. In this way, the UE and the base station can switch to at least one new beam for communication after an attempt to receive a downlink transmission via one or more current beams fails. In this way, the UE and the base station can save computational, communication, and / or network resources that might have been used to attempt to transmit and receive additional downlink transmissions via the beams through which the UE has not received a downlink transmission.

[0088] Figure 3 This is a diagram illustrating example 300 of beam switching based at least in part on the receipt of a NACK according to this disclosure. As shown, the UE (e.g., UE 120) and the base station (e.g., base station 110) may communicate using one or more of RRC signaling, reference signals, measurement reports, downlink transmissions, HARQ feedback, downlink control information (DCI), etc. In some aspects, the base station and the UE may be part of a wireless network (e.g., wireless network 100).

[0089] like Figure 3 As shown by reference numeral 305 in the accompanying drawings, the base station may transmit RRC signaling to the UE. RRC signaling may include one or more indications for configuration of the UE. In some aspects, RRC signaling may include one or more indications associated with scheduling downlink transmissions (e.g., semi-persistent scheduling). In some aspects, RRC signaling may include RRC reconfiguration (RRCReconfiguration or RRCR) having information elements for configuring a cell group (e.g., CellGroupConfig). The information elements for configuring a cell group may include a serving cell configuration (e.g., ServingCellConfiguration) having information elements for configuring Channel State Information (CSI) measurements (e.g., CSI-MeasConfig). In some aspects, RRC signaling may include RRC setup (e.g., RRCSetup) messages and / or RRC recovery (e.g., RRCResume) messages for configuring the UE to monitor CSI Reference Signals (CSI-RS).

[0090] In some aspects, RRC signaling can instruct the UE to monitor a candidate beam set to search for one or more reference signals when performing reference signal (e.g., CSI-RS) measurements. In some aspects, RRC signaling can instruct the UE to monitor one or more new beams in the candidate beam set in response to the transmission of a NACK for a downlink transmission received via one or more current beams. In some aspects, RRC signaling can instruct the UE to monitor one or more new beams in the candidate beam set in response to the transmission of a NACK for a downlink transmission not received by one or more current beams for a threshold number of times (e.g., consecutive downlink transmissions of the threshold number, partial downlink transmissions of the threshold number, downlink transmissions received over a time period of the threshold number, etc.).

[0091] In some respects, RRC signaling can indicate the number of beams to monitor for downlink transmissions, the number of new beams to monitor for downlink transmission retransmissions, and so on. In other respects, RRC signaling can indicate the procedures for selecting one or more new beams to monitor downlink transmission retransmissions. For example, RRC signaling can instruct the UE to monitor several top-ranked beams from the most recent measurement report (e.g., including one or more current beams or excluding one or more current beams).

[0092] As indicated by reference numeral 310, the UE can be configured at least partially based on this RRC signaling. In some aspects, the UE can be configured to monitor one or more beams in a candidate beam set to search for one or more downlink transmissions. For example, the UE can configure one or more components of the UE to use one or more antennas of the UE to monitor bandwidth portions. In some aspects, the UE can be configured to monitor one or more new beams in the candidate beam set at least partially based on transmitting NACKs for downlink transmissions. In some aspects, the UE can be configured (e.g., at least partially based on semi-persistent scheduling) to receive multiple downlink transmissions during multiple downlink transmission opportunities scheduled via RRC.

[0093] As indicated by reference numeral 315 in the accompanying drawings, the UE may transmit an indication of configuration completion. In some aspects, the UE may transmit this indication in an RRC reconfiguration complete (e.g., RRCReconfigurationComplete or RRCRC) message. Based at least in part on receiving the indication of configuration completion, the base station may determine that the UE is configured to perform one or more procedures configured for that UE (e.g., semi-persistent scheduling, monitoring a set of candidate beams to find one or more reference signals, monitoring one or more new beams based at least in part on transmitting NACK, etc.).

[0094] As shown by reference numeral 320, a base station may transmit one or more reference signals (e.g., CSI-RS) via a candidate beam set. In some aspects, the base station may use beam sweeping to transmit the one or more reference signals.

[0095] As shown by reference numeral 325, the UE can obtain measurements of the one or more reference signals received on the candidate beam set. In some aspects, the UE can identify the beam identifier associated with the received reference signal based at least in part on the timing of the UE receiving the reference signal and an indication of the time when the base station is scheduled to transmit the one or more reference signals via the candidate beam set.

[0096] As indicated by reference numeral 330, the UE may transmit a measurement report to the base station. The measurement report may include the obtained measurements of the reference signal (such as RSRP, RSSI, RSRQ and / or CQI), the ranking of the candidate beam set (e.g., based at least in part on the obtained measurements), and so on.

[0097] As indicated by reference numeral 335, the UE may determine the ranking of the candidate beam set based at least in part on measurements of the reference signal. In some respects, the ranking may be based at least in part on the order of signal quality from highest to lowest (e.g., as indicated by RSRP, RSSI, RSRQ, CQI, etc.).

[0098] As indicated by reference numeral 340 in the accompanying figure, the UE can determine the ranking of candidate beams. In some aspects, the base station can determine the ranking of candidate beams based at least in part on the ranking indicated in the measurement report, at least in part on measurements of reference signals indicated in the measurement report, etc. In some aspects, the base station and the UE can be configured to determine the ranking of the candidate beam set based at least in part on the same procedures and / or metrics, such that the base station and the UE agree on the ranking.

[0099] In some respects, the UE and the base station can be configured to automatically activate several top-ranked candidate beams for communication between the UE and the base station. In some respects, these top-ranked candidate beams can be based at least in part on RRC signaling, DCI messages, etc.

[0100] As shown by reference numeral 345 in the accompanying drawings, a base station may transmit downlink transmissions to a UE. In some aspects, the base station may use a subset of the highest-ranking candidate beams that are activated to transmit downlink transmissions. In some aspects, the base station may select one or more beams for transmitting downlink transmissions based at least in part on an indication provided to the UE. For example, the base station may select the one or more beams based at least in part on RRC signaling directed to the UE indicating that the base station is configured to transmit downlink transmissions via one or more beams with the highest-ranking CQI. In some aspects, the base station may select the number of the one or more beams based at least in part on an indication provided to the UE. For example, the base station may select two beams as the number of the one or more beams based at least in part on RRC signaling indicating to the UE that the base station is configured to transmit downlink transmissions via two beams. In some aspects, the base station may transmit a DCI (e.g., a Transmission Configuration Indicator (TCI) state-activated DCI) to indicate that the base station is configured to transmit downlink transmissions via one or more of the activated highest-ranking candidate beams.

[0101] In some respects, the base station may transmit downlink transmissions during a previously scheduled downlink transmission opportunity (e.g., using RRC signaling). In other respects, the UE may not receive downlink transmissions during the downlink transmission opportunity.

[0102] As shown by reference numeral 350, the UE may transmit a NACK as a HARQ feedback for downlink transmission scheduled for one or more beams in the candidate beam set. In some aspects, the UE may transmit the NACK via one or more beams in the candidate beam set (e.g., one or more current beams), and the base station may receive the NACK via the one or more beams.

[0103] As indicated by reference numeral 355, a base station may identify a NACK as a HARQ feedback associated with a downlink transmission carried via one or more beams in the candidate beam set. In some aspects, a base station may interpret the timing of a HARQ feedback as a NACK at least in part based on the absence of an ACK during the timing of the HARQ feedback. In other words, a base station may consider the failure to receive an ACK during the timing of the HARQ feedback as equivalent to receiving a NACK.

[0104] In some aspects, based at least in part on receiving a NACK associated with a downlink transmission, the base station can determine that it will transmit the retransmission of the downlink transmission via one or more new beams from the candidate beam set. In some aspects, the base station can select the one or more new beams at least in part based on their ranking within the measurement report. In some aspects, the base station can determine the timing offset between receiving the measurement report and the timing of the NACK feedback. In some aspects, the base station can determine to retransmit the downlink transmission via the one or more new beams at least in part based on the timing offset meeting a threshold. This avoids beam switching to one or more new beams at least in part based on outdated information. This can save computational, communication, and / or network resources that might otherwise be consumed by beam switching to one or more new beams for subsequent downlink transmissions that may fail for subsequent downlink transmissions but ranked high at the time of the outdated measurement report.

[0105] As shown by reference numeral 360 in the attached figure, the base station can transmit a DCI to activate one or more new TCI states. These one or more new TCI states can be associated with one or more new beams. In some aspects, the base station can transmit a DCI within a DCI message to activate the one or more new beams used for monitoring retransmissions of the downlink transmission.

[0106] As indicated by reference numeral 365, the base station may retransmit the downlink transmission via one or more new beams from the candidate beam set. In some aspects, the base station may retransmit the downlink transmission via the one or more new beams after the timing of a NACK feedback without transmitting an instruction to activate the one or more new beams.

[0107] In some aspects, retransmitting downlink transmissions may include performing beam sweeping using one or more new beams. In some aspects, beam sweeping may include retransmitting downlink transmissions via the one or more new beams, one or more beams that have already transmitted downlink transmissions via them, or a combination of the one or more new beams and one or more beams that have already transmitted downlink transmissions via them. In some aspects, beam sweeping may be performed sequentially, the order being at least in part based on the ranking of the beam sets, a set of measurements of one or more reference signals received using candidate beam sets, and so on.

[0108] In some respects, a base station can retransmit downlink transmissions via several new beams without beam sweeping. In some respects, a base station can select the number of one or more new beams for retransmitting downlink transmissions based at least in part on an instruction provided to the UE. In some respects, a UE can select the one or more new beams for retransmitting the downlink transmission based at least in part on measurements of a reference signal set, measurement reports, ranking of beam sets, etc.

[0109] As indicated by reference numeral 370, the UE may monitor one or more new beams in the candidate beam set to look for retransmissions of the downlink transmission. In some respects, the UE may determine to monitor the one or more new beams based at least in part on the DCI used to activate one or more new TCI states.

[0110] In some respects, the UE may select the one or more new beams for monitoring retransmissions of the downlink transmission based at least in part on measurements of one or more reference signals, ranking of candidate beam sets, etc. In some respects, the UE may select the number of the one or more new beams based at least in part on the UE's configuration (e.g., at least in part on RRC signaling, DCI, etc.).

[0111] In some aspects, the UE may determine whether to monitor the one or more new beams based at least in part on a timing threshold being met between the timing offset between the transmitted measurement report and the transmitted NACK. In other aspects, the base station may indicate the threshold to the UE so that the UE and the base station can synchronize for transmitting and monitoring transmissions via the one or more new beams.

[0112] As indicated by reference numeral 375, the UE may transmit an ACK as HARQ feedback for retransmissions of downlink transmissions. In some aspects, the UE may receive retransmissions of downlink transmissions via at least one of the one or more new beams and transmit an ACK to identify at least one of the one or more new beams. In some aspects, the UE may transmit an ACK to identify the number of the one or more new beams (e.g., based at least in part on measurements of one or more reference signals received using a candidate beam set, the ranking of the candidate beam set, etc.) (e.g., based at least in part on the UE's configuration).

[0113] In some respects, the UE may transmit the ACK via at least one of the one or more new beams. The base station may interpret the ACK as an indication that the UE will use the one or more beams through which it transmitted the ACK to transmit and / or receive subsequent communications.

[0114] Based at least in part on beam switching for retransmissions of downlink transmissions (which is based at least in part on NACK for downlink transmissions), the UE and the base station can save computational, communication and / or network resources that might otherwise have been used to attempt to transmit and receive additional downlink transmissions through the beam through which the UE failed to receive the downlink transmission.

[0115] As indicated above, Figure 3 This is provided as an example. Other examples may differ from the one provided. Figure 3 The example described.

[0116] Figure 4 This is a diagram illustrating example 400 of beam switching based at least in part on the receipt of a NACK according to this disclosure. As shown, the UE (e.g., UE 120) and the base station (e.g., base station 110, such as a gNB) can communicate using one or more of RRC signaling, reference signals, measurement reports, downlink transmissions, HARQ feedback, DCI, etc. In some aspects, the base station and the UE can be part of a wireless network (e.g., wireless network 100).

[0117] like Figure 4 As shown in loop 410, the base station can transmit a downlink transmission with sequence number 0 via beam 1 and beam 2. The base station can use a Physical Downlink Shared Channel (PDSCH) to transmit this downlink transmission. The PDSCH can be scheduled using semi-persistent scheduling. The UE can receive the downlink transmission with sequence number 0 and can determine whether to transmit an ACK or not to transmit HARQ feedback (e.g., at least in part based on the UE being configured for discontinuous transmission (DTX) for HARQ feedback). The base station can interpret an ACK or the absence of any HARQ feedback in the case of discontinuous transmission as an indication that the UE has received a downlink transmission with sequence number 0 from at least one of beam 1 or beam 2, or from both beam 1 and beam 2 (e.g., if the UE is configured to use soft NACK). In some aspects, the downlink transmission with sequence number 0 may expire at the end of loop 410.

[0118] As also shown in loop 410, the base station can transmit RRC signaling, such as RRCR messages, RRC setup messages, RRC recovery messages, etc. RRC signaling can instruct the UE to be configured to monitor a candidate beam set to find one or more reference signals, perform beam switching for downlink retransmissions based at least in part on NACK for downlink transmissions, etc. The UE can also transmit indications about what it has been configured for (e.g., RRCRC messages) based at least in part on RRC signaling.

[0119] As further illustrated in cycle 410, the base station may transmit one or more reference signals (e.g., CSI-RS) via a candidate beam set. The UE may monitor the candidate beam set and obtain measurements of the reference signals. In some aspects, the UE may determine the ranking of the candidate beam set based at least in part on the measurements. In some aspects, the UE may automatically activate several of the highest-ranking candidate beams to communicate with the base station.

[0120] The UE can transmit a measurement report (MR) to the base station. In some aspects, the base station can determine the ranking of the candidate beam set based at least in part on measurements, indications of the ranking of candidate beam sets within the measurement report, etc. In this way, the base station and the UE can agree on the ranking of the candidate beam set. In some aspects, the base station can automatically activate the highest-ranking candidate beams to communicate with the UE.

[0121] As shown in loop 420, the base station can transmit a downlink transmission with sequence number 1 via beams 1 and 2. The downlink transmission may include a DCI indicating TCI state activation (e.g., if the UE is not configured to automatically activate the several highest-ranking candidate beams to communicate with the base station). In some aspects, the downlink transmission may include an indication of the interpretation of HARQ feedback from a previous downlink transmission (e.g., ACK in loop 410). Beams 1 and 2 may be blocked, and the UE may not receive the downlink transmission with sequence number 1 during the scheduled time for receiving the downlink transmission.

[0122] The UE may transmit a NACK via beam 1 and / or beam 2 (e.g., using the Physical Uplink Control Channel (PUCCH)) to indicate that the UE has not received a downlink transmission with sequence number 1. In some aspects, the UE has not received the downlink transmission with sequence number 1 at least in part due to interference in the vicinity of the UE (e.g., from one or more other cells). In some aspects, the base station may use the beam on which the UE has not received a downlink transmission with sequence number 1 to receive a NACK from the UE. In some aspects, the downlink transmission with sequence number 1 may expire at the end of cycle 420.

[0123] As shown in loop 420, the base station may retransmit the downlink transmission with sequence number 1 via one or more new beams (e.g., beam 3 and beam 4). In some aspects, the downlink transmission may include a DCI for indicating the activation of a new TCI state (e.g., if the UE is not configured to automatically activate several top-ranked candidate beams other than the current beam after transmitting a NACK). In some aspects, the base station may select the one or more new beams at least in part based on a set of measurements of one or more reference signals, the ranking of the candidate beam set, etc. For example, the base station may select beam 3 and beam 4 at least in part based on the fact that beam 3 and beam 4 are two top-ranked candidate beams other than beam 1 and beam 2.

[0124] The UE may select one or more new beams, at least in part, based on a set of measurements of one or more reference signals, a ranking of candidate beam sets, etc., to monitor retransmissions of downlink transmissions with sequence number 1. The UE may be configured to select one or more new beams using the same basis used by the base station to select them, so that the UE and the base station are synchronized.

[0125] The UE can receive retransmissions of downlink transmissions with sequence number 1 and can determine whether to transmit an ACK or not to transmit HARQ feedback. The base station can interpret an ACK or the absence of any HARQ feedback in the case of discontinuous transmissions configured for HARQ feedback as an indication that the UE has received a downlink transmission with sequence number 1 from at least one of beam 3 or beam 4, or from both beam 3 and beam 4 (e.g., if the UE is configured to use soft NACK).

[0126] The base station and the UE can use the one or more new beams to convey at least one additional message. For example, the base station can transmit a downlink transmission with sequence number 2 via beams 3 and 4. The UE can monitor beams 3 and 4 to locate the downlink transmission with sequence number 2 and transmit HARQ feedback for the downlink transmission with sequence number 2.

[0127] As indicated above, Figure 4 This is provided as an example. Other examples may differ from the one provided. Figure 4 The example described.

[0128] Figure 5This is a diagram illustrating an example 500 of beam switching based at least in part on the receipt of a NACK according to this disclosure. As shown, the UE (e.g., UE 120) and the base station (e.g., base station 110) may communicate using one or more of RRC signaling, reference signals, measurement reports, downlink transmissions, HARQ feedback, DCI, etc. In some aspects, the base station and the UE may be part of a wireless network (e.g., wireless network 100).

[0129] like Figure 5 As shown in cycle 510, the base station can transmit a downlink transmission with sequence number 0 via beam 1 and beam 2. The base station can use PDSCH to transmit the downlink transmission. PDSCH can be scheduled using semi-persistent scheduling. The UE can receive the downlink transmission with sequence number 0 and can determine whether to transmit an ACK or not to transmit HARQ feedback. The base station can interpret an ACK or the absence of any HARQ feedback in the case of discontinuous transmission as an indication that the UE has received a downlink transmission with sequence number 0 from at least one of beam 1 or beam 2, or from both beam 1 and beam 2 (e.g., if the UE is configured to use soft NACK). In some aspects, the downlink transmission with sequence number 0 may expire at the end of cycle 510.

[0130] As also shown in cycle 510, the base station can transmit RRC signaling, such as RRCR messages, RRC setup messages, RRC recovery messages, etc. RRC signaling can instruct the UE to be configured to monitor a candidate beam set to find one or more reference signals, perform beam switching for downlink retransmissions based at least in part on NACK for downlink transmissions, etc. The UE can also transmit indications about what it has been configured for (e.g., RRCRC messages) based at least in part on RRC signaling.

[0131] As further illustrated in cycle 510, the base station may transmit one or more reference signals (e.g., CSI-RS) via a candidate beam set. The UE may monitor the candidate beam set and obtain measurements of the reference signals. In some aspects, the UE may determine the ranking of the candidate beam set based at least in part on the measurements. In some aspects, the UE may automatically activate several of the highest-ranking candidate beams to communicate with the base station.

[0132] The UE can transmit measurement reports to the base station. In some aspects, the base station can determine the ranking of the candidate beam set based at least in part on measurements, indications of the ranking of candidate beam sets within the measurement report, and so on. In this way, the base station and the UE can have synchronized rankings of the candidate beam sets. In some aspects, the base station can automatically activate the highest-ranking candidate beams to communicate with the UE.

[0133] As shown in cycle 520, the base station can transmit a downlink transmission with sequence number 1 via beams 1 and 2. The downlink transmission may include a DCI indicating TCI state activation (e.g., if the UE is not configured to automatically activate the several highest-ranking candidate beams to communicate with the base station). In some aspects, the downlink transmission may include an indication of the interpretation of HARQ feedback from a previous downlink transmission (e.g., the ACK in cycle 510). Beams 1 and 2 may be blocked, and the UE may not receive the downlink transmission with sequence number 1 during the scheduled time for receiving the downlink transmission.

[0134] The UE may transmit a NACK via beam 1 and / or beam 2 (e.g., using PUCCH) to indicate that the UE has not received a downlink transmission with sequence number 1. In some aspects, the UE has not received a downlink transmission with sequence number 1 at least in part due to interference near the UE (e.g., from one or more other cells). In some aspects, the base station may receive a NACK from the UE using the beam on which the UE has not received a downlink transmission with sequence number 1. In some aspects (e.g., in the case of discontinuous transmissions without HARQ feedback configured), the base station may interpret the timing for receiving HARQ feedback as a NACK at least in part based on the failure to receive any HARQ feedback from the UE. In some aspects, the downlink transmission with sequence number 1 may expire at the end of cycle 520.

[0135] As also shown in loop 520, the base station can perform beam sweeping using one or more new beams and / or beam 1 and beam 2. In some aspects, the base station can transmit downlink transmissions with sequence number 1 sequentially (e.g., chronologically) via one or more new beams and / or beam 1 and beam 2, based at least in part on measurements of one or more reference signals received using candidate beam sets, the ranking of candidate beam sets, etc. In some aspects, the UE can be configured to monitor multiple beams simultaneously, and the base station can perform beam sweeping by retransmitting downlink transmissions simultaneously using multiple beams.

[0136] In some respects, the UE can monitor the new beam and / or beam 1 and beam 2 to look for retransmissions of downlink transmissions. The UE can transmit an ACK to indicate that the UE has received a retransmission of the downlink transmission using at least one of the new beams. In some respects, the UE can use the same beam on which it received the retransmission to transmit the ACK.

[0137] In some aspects, the base station may perform beam sweeping using beam 1, beam 2, and one or more new beams selected for subsequent communication. In some aspects, the base station may use beam sweeping to indicate that the one or more new beams (e.g., beam 3 and beam 4) will be used for subsequent communication. In some aspects, the UE may use the one or more new beams to transmit ACK, or may determine not to transmit HARQ feedback (e.g., at least in part based on the UE being configured for DTX for HARQ feedback).

[0138] The base station can interpret ACK or no HARQ feedback as an indication that the UE has received a downlink transmission with sequence number 1 from at least one of beam 3 and beam 4 or from both beam 3 and beam 4 (e.g., if the UE is configured to use soft NACK).

[0139] The base station and the UE can use the one or more new beams to convey at least one additional message. For example, the base station can transmit a downlink transmission with sequence number 2 via beams 3 and 4. The UE can monitor beams 3 and 4 to locate the downlink transmission with sequence number 2 and transmit HARQ feedback for the downlink transmission with sequence number 2.

[0140] As indicated above, Figure 5 This is provided as an example. Other examples may differ from the one provided. Figure 5 The example described.

[0141] Figure 6 This is a diagram illustrating an example procedure 600 performed by a UE according to this disclosure. Example procedure 600 is an example in which a UE (e.g., UE 120, etc.) performs operations associated with beam switching upon receiving a NACK.

[0142] like Figure 6 As shown, in some aspects, process 600 may include transmitting a measurement report (block 610) based at least in part on a set of measurements of one or more reference signals received using a candidate beam set. For example, a UE (e.g., using controller / processor 280, transmit processor 264, TX MIMO processor 266, MOD 254, antenna 252, etc.) may transmit a measurement report based at least in part on a set of measurements of one or more reference signals received using a candidate beam set, as described above.

[0143] like Figure 6As further shown, in some aspects, process 600 may include: transmitting a NACK (block 620) for downlink transmissions scheduled for one or more beams in the candidate beam set. For example, a UE (e.g., using controller / processor 280, transmit processor 264, TX MIMO processor 266, MOD 254, antenna 252, etc.) may transmit a NACK for downlink transmissions scheduled for one or more beams in the candidate beam set, as described above.

[0144] like Figure 6 As further shown, in some aspects, process 600 may include: monitoring one or more new beams in the candidate beam set to look for retransmissions of the downlink transmission (block 630). For example, the UE (e.g., using antenna 252, DEMOD 254, MIMO detector 256, receive processor 258, controller / processor 280, etc.) may monitor one or more new beams in the candidate beam set to look for retransmissions of the downlink transmission, as described above.

[0145] Process 600 may include additional aspects, such as any single aspect or any combination of aspects described below and / or in conjunction with one or more other processes described elsewhere herein.

[0146] In a first aspect, process 600 includes: receiving RRC reconfiguration signaling, the RRC reconfiguration signaling including an indication regarding monitoring the candidate beam set to find one or more reference signals; configuring the UE to monitor the candidate beam set to find the one or more reference signals; and transmitting an indication regarding the UE being configured to monitor the candidate beam set to find the one or more reference signals.

[0147] In a second aspect, either alone or in combination with the first aspect, process 600 includes: obtaining measurements of one or more reference signals received on a candidate beam set; and determining a ranking of candidate beams in the candidate beam set based at least in part on the measurements of the one or more reference signals.

[0148] In a third aspect, either alone or in combination with one or more of the first and second aspects, process 600 includes: selecting the one or more beams for receiving the downlink transmission based at least in part on a set of measurements of the one or more reference signals.

[0149] In the fourth aspect, either alone or in combination with one or more of the first to third aspects, process 600 includes: further selecting the number of the one or more beams based at least in part on the configuration of the UE.

[0150] In a fifth aspect, either alone or in combination with one or more of the first to fourth aspects, process 600 includes: selecting one or more new beams for monitoring retransmissions of the downlink transmission based at least in part on a set of measurements of the one or more reference signals.

[0151] In the sixth aspect, either alone or in combination with one or more of the first to fifth aspects, process 600 includes: further selecting the number of the one or more new beams based at least in part on the configuration of the UE.

[0152] In a seventh aspect, alone or in combination with one or more of the first to sixth aspects, process 600 includes: determining that a timing offset between transmitting the measurement report and transmitting the NACK satisfies a timing threshold, wherein monitoring the one or more new beams to find retransmissions of the downlink transmission is based at least in part on determining that the timing offset satisfies the timing threshold.

[0153] In the eighth aspect, alone or in combination with one or more of the first to seventh aspects, process 600 includes: receiving a DCI message activating the one or more new beams for monitoring retransmissions of the downlink transmission.

[0154] In the ninth aspect, monitoring one or more new beams in the candidate beam set to search for retransmission of the downlink transmission, either alone or in combination with one or more of the first to eighth aspects, includes: monitoring the one or more new beams in the candidate beam set to search for retransmission of the downlink transmission after transmitting a NACK without receiving an instruction from the base station to activate the one or more new beams.

[0155] In the tenth aspect, alone or in combination with one or more of the first to ninth aspects, process 600 includes: receiving a retransmission of the downlink transmission via at least one of the one or more new beams.

[0156] In the eleventh aspect, alone or in combination with one or more of the first to tenth aspects, process 600 includes: transmitting an ACK for retransmission of the downlink transmission via at least one of the one or more new beams.

[0157] In the twelfth aspect, alone or in combination with one or more of the first to eleventh aspects, process 600 includes: transmitting at least one additional message via at least one of the one or more new beams.

[0158] although Figure 6 An example box of process 600 is shown, but in some respects, process 600 may include... Figure 6The boxes depicted in the process are compared to additional boxes, fewer boxes, different boxes, or boxes arranged differently. Additionally or alternatively, two or more boxes in process 600 can be executed in parallel.

[0159] Figure 7 This is a diagram illustrating an example process 700 performed by a base station according to this disclosure. Example process 700 is an example in which a base station (e.g., base station 110, etc.) performs operations associated with beam switching upon receiving a NACK.

[0160] like Figure 7 As shown, in some aspects, process 700 may include receiving a measurement report from the UE indicating a measurement set of one or more reference signals received using a candidate beam set (block 710). For example, a base station (e.g., using antenna 234, DEMOD 232, MIMO detector 236, receive processor 238, controller / processor 240, etc.) may receive a measurement report from the UE indicating a measurement set of one or more reference signals received using a candidate beam set, as described above.

[0161] like Figure 7 As further shown, in some aspects, process 700 may include identifying NACK feedback associated with downlink transmissions transmitted via one or more beams in the candidate beam set (block 720). For example, a base station (e.g., using antenna 234, DEMOD 232, MIMO detector 236, receive processor 238, controller / processor 240, etc.) may identify NACK feedback associated with downlink transmissions transmitted via one or more beams in the candidate beam set, as described above.

[0162] like Figure 7 As further shown, in some aspects, process 700 may include: transmitting a retransmission of the downlink transmission via one or more new beams from the candidate beam set (block 730). For example, a base station (e.g., using controller / processor 240, transmit processor 220, TX MIMO processor 230, MOD 232, antenna 234, etc.) may transmit the retransmission of the downlink transmission via one or more new beams from the candidate beam set, as described above.

[0163] Process 700 may include additional aspects, such as any single aspect or any combination of aspects described below and / or in conjunction with one or more other processes described elsewhere herein.

[0164] In the first aspect, retransmitting downlink transmissions includes using one or more new beams to perform beam sweeping.

[0165] In a second aspect, either alone or in combination with the first aspect, process 700 includes: using one or more new beams and the one or more new beams to perform beam sweeping.

[0166] In a third aspect, either alone or in combination with one or more of the first and second aspects, process 700 includes: transmitting RRC reconfiguration signaling, the RRC reconfiguration signaling including an indication regarding monitoring the candidate beam set to find one or more reference signals; and receiving an indication regarding the UE being configured to monitor the candidate beam set to find the one or more reference signals.

[0167] In the fourth aspect, either alone or in combination with one or more of the first to third aspects, process 700 includes: determining the ranking of candidate beams in the candidate beam set based at least in part on the measurement set of the one or more reference signals.

[0168] In a fifth aspect, either alone or in combination with one or more of the first to fourth aspects, process 700 includes: selecting the one or more beams for transmitting the downlink transmission based at least in part on a set of measurements of the one or more reference signals.

[0169] In the sixth aspect, alone or in combination with one or more of the first to fifth aspects, process 700 includes: selecting the number of the one or more beams based at least in part on an instruction provided to the UE.

[0170] In the seventh aspect, alone or in combination with one or more of the first to sixth aspects, process 700 includes: selecting the one or more new beams for retransmitting the downlink transmission based at least in part on a set of measurements of the one or more reference signals.

[0171] In the eighth aspect, alone or in combination with one or more of the first to seventh aspects, process 700 includes: selecting the number of the one or more new beams based at least in part on an instruction provided to the UE.

[0172] In the ninth aspect, alone or in combination with one or more of the first to eighth aspects, process 700 includes: determining that the timing offset between the timing of receiving the measurement report and the timing of the NACK feedback meets a timing threshold, wherein the retransmission of the downlink transmission via the one or more new beams is based at least in part on determining that the timing offset meets the timing threshold.

[0173] In the tenth aspect, alone or in combination with one or more of the first to ninth aspects, process 700 includes: transmitting a DCI message activating the one or more new beams for monitoring retransmissions of the downlink transmission.

[0174] In the eleventh aspect, retransmitting the downlink transmission via the one or more new beams, either alone or in combination with one or more of the first to tenth aspects, includes: retransmitting the downlink transmission via the one or more new beams after the timing of a NACK feedback without transmitting an instruction to activate the one or more new beams.

[0175] In the twelfth aspect, alone or in combination with one or more of the first to eleventh aspects, process 700 includes: receiving an ACK for a retransmission of the downlink transmission via at least one of the one or more new beams.

[0176] In the thirteenth aspect, alone or in combination with one or more of the first to twelfth aspects, process 700 includes: transmitting at least one additional message via at least one of the one or more new beams.

[0177] In the fourteenth aspect, either alone or in combination with one or more of the first to thirteenth aspects, identifying a NACK feedback associated with a downlink transmission includes interpreting the timing of a HARQ feedback as NACK based at least in part on the absence of an ACK received during the timing of the HARQ feedback.

[0178] although Figure 7 An example box of process 700 is shown, but in some respects, process 700 may include... Figure 7 The boxes depicted in the process are compared to additional boxes, fewer boxes, different boxes, or boxes arranged differently. Additionally or alternatively, two or more boxes in process 700 can be executed in parallel.

[0179] The following provides an overview of some aspects of this disclosure:

[0180] Aspect 1: A wireless communication method performed by a user equipment (UE) comprising: transmitting a measurement report based at least in part on a set of measurements of one or more reference signals received using a set of candidate beams; transmitting a negative acknowledgment of a downlink transmission scheduled for one or more beams in the set of candidate beams; and monitoring one or more new beams in the set of candidate beams to seek retransmissions of the downlink transmission.

[0181] Aspect 2: The method of Aspect 1 further includes: receiving Radio Resource Control (RRC) reconfiguration signaling, the RRC reconfiguration signaling including an indication regarding monitoring the candidate beam set to find one or more reference signals; configuring the UE to monitor the candidate beam set to find the one or more reference signals; and transmitting an indication regarding the UE being configured to monitor the candidate beam set to find the one or more reference signals.

[0182] Aspect 3: The method of aspect 2 further includes: obtaining measurements of one or more reference signals received on the candidate beam set; and determining the ranking of candidate beams in the candidate beam set based at least in part on the measurements of the one or more reference signals.

[0183] Aspect 4: The method of any of Aspects 1-3 further includes: selecting the one or more beams for receiving the downlink transmission based at least in part on a set of measurements of the one or more reference signals.

[0184] Aspect 5: The method of any of Aspects 1-4 further includes: further selecting the number of the one or more beams based at least in part on the configuration of the UE.

[0185] Aspect 6: The method of any of Aspects 1-5 further includes: selecting the one or more new beams for monitoring retransmissions of the downlink transmission based at least in part on a set of measurements of the one or more reference signals.

[0186] Aspect 7: The method of any of Aspects 1-6 further includes: further selecting the number of the one or more new beams based at least in part on the configuration of the UE.

[0187] Aspect 8: The method of any of Aspects 1-7 further includes: determining that a timing offset between transmitting the measurement report and transmitting the negative acknowledgment satisfies a timing threshold, wherein monitoring the one or more new beams to find retransmissions of the downlink transmission is based at least in part on determining that the timing offset satisfies the timing threshold.

[0188] Aspect 9: The method of any of Aspects 1-8 further includes: receiving a downlink control information message that activates the one or more new beams for monitoring retransmissions of the downlink transmission.

[0189] Aspect 10: The method of any of Aspects 1-9, wherein monitoring one or more new beams in the candidate beam set to find retransmissions of the downlink transmission comprises: monitoring the one or more new beams in the candidate beam set to find retransmissions of the downlink transmission after transmitting the negative acknowledgment without receiving an instruction from the base station to activate the one or more new beams.

[0190] Aspect 11: The method of any of Aspects 1-10 further includes: receiving a retransmission of the downlink transmission via at least one of the one or more new beams.

[0191] Aspect 12: The method of aspect 11 further includes: transmitting confirmation of retransmission for downlink transmissions received via the one or more new beams.

[0192] Aspect 13: The method of aspect 12 further includes: transmitting at least one additional message via the at least one of the one or more new beams.

[0193] Aspect 14: A wireless communication method performed by a base station, comprising: receiving a measurement report from a user equipment (UE) indicating a measurement set of one or more reference signals received using a candidate beam set; identifying a negative reception feedback associated with a downlink transmission transmitted via one or more beams in the candidate beam set; and retransmitting the downlink transmission via one or more new beams in the candidate beam set.

[0194] Aspect 15: The method of aspect 14, wherein retransmitting the downlink transmission includes: using one or more new beams to perform beam sweeping.

[0195] Aspect 16: The method of aspect 15 further includes: using one or more new beams and the one or more beams to perform the beam sweep.

[0196] Aspect 17: The method of any of Aspects 14-16 further includes: transmitting radio resource control (RRC) reconfiguration signaling including an indication regarding monitoring the candidate beam set to search for one or more reference signals; and receiving an indication regarding the UE being configured to monitor the candidate beam set to search for the one or more reference signals.

[0197] Aspect 18: The method of any of Aspects 14-17 further includes: determining the ranking of candidate beams in the candidate beam set based at least in part on a set of measurements of the one or more reference signals.

[0198] Aspect 19: The method of any of Aspects 14-18 further includes: selecting the one or more beams for transmitting the downlink transmission based at least in part on a set of measurements of the one or more reference signals.

[0199] Aspect 20: The method of any of Aspects 14-19 further includes: selecting the number of the one or more beams based at least in part on an instruction provided to the UE.

[0200] Aspect 21: The method of any of Aspects 14-20 further includes: selecting the one or more new beams for retransmitting the downlink transmission based at least in part on a set of measurements of the one or more reference signals.

[0201] Aspect 22: The method of any of Aspects 14-21 further includes: selecting the number of the one or more new beams based at least in part on an instruction provided to the UE.

[0202] Aspect 23: The method of any of Aspects 14-22 further includes: determining that the timing offset between the timing of receiving the measurement report and the timing of the negative reception feedback satisfies a timing threshold, wherein the retransmission of the downlink transmission via the one or more new beams is based at least in part on determining that the timing offset satisfies the timing threshold.

[0203] Aspect 24: The method of any of Aspects 14-23 further includes: transmitting a downlink control information message that activates the one or more new beams for monitoring retransmissions of the downlink transmission.

[0204] Aspect 25: The method of any of Aspects 14-24, wherein retransmitting the downlink transmission via the one or more new beams comprises: retransmitting the downlink transmission via the one or more new beams without transmitting an instruction to activate the one or more new beams after the timing of the negative acceptance feedback.

[0205] Aspect 26: The method of any of Aspects 14-25 further includes: receiving confirmation of retransmission for the downlink transmission via at least one of the one or more new beams.

[0206] Aspect 27: The method of any of Aspects 14-26 further includes: transmitting at least one additional message via the at least one of the one or more new beams.

[0207] Aspect 28: The method of any of Aspects 14-27, wherein identifying a negative acknowledgment feedback associated with the downlink transmission includes: interpreting the timing of a HARQ feedback as a negative acknowledgment based at least in part on the absence of an acknowledgment during the timing of a Hybrid Automatic Repeat Request (HARQ) feedback.

[0208] Aspect 29: An apparatus for wireless communication at a device, comprising: a processor; a memory coupled to the processor; and instructions stored in the memory and executable by the processor to cause the apparatus to perform methods as described in one or more of aspects 1-28.

[0209] Aspect 30: An apparatus for wireless communication, comprising a memory and one or more processors coupled to the memory, the memory and the one or more processors being configured to perform methods as described in one or more aspects of aspects 1-28.

[0210] Aspect 31: An apparatus for wireless communication, comprising at least one means for performing a method as described in one or more aspects of aspects 1-28.

[0211] Aspect 32: A non-transient computer-readable medium storing code for wireless communication, the code including instructions executable by a processor to perform methods as described in one or more aspects of aspects 1-28.

[0212] Aspect 33: A non-transient computer-readable medium storing a set of instructions for wireless communication, the set of instructions including one or more instructions which, when executed by one or more processors of a device, cause the device to perform methods as described in one or more aspects of aspects 1-28.

[0213] The foregoing disclosure provides explanations and descriptions, but is not intended to be exhaustive or to limit the aspects to the precise forms disclosed. Modifications and variations may be made in light of the foregoing disclosure or may be obtained through practice.

[0214] As used herein, the term "component" is intended to be broadly interpreted as hardware and / or a combination of hardware and software. "Software" should be broadly interpreted as instructions, instruction sets, code, code segments, program code, programs, subroutines, software modules, applications, software applications, software packages, routines, subroutines, objects, executables, threads of execution, procedures, and / or functions, whether referred to as software, firmware, middleware, microcode, hardware description languages, or other terms. As used herein, processors are implemented using hardware and / or a combination of hardware and software. It will be apparent that the systems and / or methods described herein can be implemented in various forms of hardware and / or combinations of hardware and software. The actual dedicated control hardware or software code used to implement these systems and / or methods is not limited in any way. Thus, the operation and behavior of these systems and / or methods are described herein without reference to any specific software code—it is understood that software and hardware can be designed to implement these systems and / or methods, at least in part, based on the descriptions herein.

[0215] As used in this article, depending on the context, a threshold can refer to a value greater than the threshold, greater than or equal to the threshold, less than the threshold, less than or equal to the threshold, equal to the threshold, not equal to the threshold, etc.

[0216] Although specific combinations of features are described in the claims and / or disclosed in the specification, these combinations are not intended to limit the disclosure of aspects. In fact, many of these features can be combined in ways not specifically described in the claims and / or not disclosed in the specification. Although each dependent claim listed below may be directly subordinated to only one claim, the disclosure of aspects includes each dependent claim being combined with each other claim in this set of claims. As used herein, the phrase “at least one of” refers to any combination of these items, including single members. As an example, “at least one of a, b, or c” is intended to cover: a, b, c, ab, ac, bc, and abc, as well as any combination having multiple identical elements (e.g., aa, aaa, aab, aac, abb, acc, bb, bbb, bbc, cc, and ccc, or any other ordering of a, b, and c).

[0217] The elements, actions, or instructions used herein should not be construed as critical or necessary unless explicitly stated otherwise. Furthermore, as used herein, the articles “a” and “a certain” are intended to include one or more items and may be used interchangeably with “one or more.” Additionally, as used herein, the article “the” is intended to include one or more items referenced in conjunction with the article “the” and may be used interchangeably with “one or more.” Furthermore, as used herein, the terms “set” (collection, group) and “group” are intended to include one or more items (e.g., related items, unrelated items, or a combination of related and unrelated items) and may be used interchangeably with “one or more.” Where only one item is intended, the phrase “only one” or similar language is used. Moreover, as used herein, the terms “have,” “contain,” “include,” etc., are intended to be open-ended terms. Furthermore, the phrase “based on” is intended to mean “at least partially based on” unless otherwise explicitly stated. Moreover, as used herein, the term “or” is intended to be inclusive when used in a sequence and may be used interchangeably with “and / or” unless otherwise explicitly stated (e.g., in combination with “either of” or “only one of”).

Claims

1. A user equipment (UE) for wireless communication, comprising: Memory; as well as One or more processors operatively coupled to the memory, the one or more processors being configured to: Measurement reports are transmitted based at least in part on a set of measurements of one or more reference signals received using a set of candidate beams, wherein the measurement reports include a ranking of the candidate beams in the set of candidate beams; The transmission receives a negative acknowledgment for downlink transmissions scheduled for one or more beams in the candidate beam set. Select one or more new beams for monitoring retransmissions of the downlink transmission and based at least in part on the ranking; as well as Monitor the one or more new beams in the candidate beam set to look for the retransmission of the downlink transmission.

2. The UE of claim 1, wherein the one or more processors are further configured to: Receive radio resource control (RRC) reconfiguration signaling including instructions regarding monitoring the candidate beam set to search for the one or more reference signals; The UE is configured to monitor the candidate beam set to find the one or more reference signals; as well as Transmit an indication that the UE is configured to monitor the candidate beam set in order to find the one or more reference signals.

3. The UE of claim 2, wherein the one or more processors are further configured to: To obtain measurements of the one or more reference signals received on the candidate beam set; and The ranking of the candidate beams in the candidate beam set is determined at least in part based on measurements of the one or more reference signals.

4. The UE of claim 1, wherein the one or more processors are further configured to: The one or more beams for receiving the downlink transmission are selected, at least in part, based on a set of measurements of the one or more reference signals.

5. The UE of claim 1, wherein the one or more processors are further configured to: The number of the one or more beams is further selected based at least in part on the configuration of the UE.

6. The UE of claim 1, wherein the one or more processors are further configured to: The selection of the one or more new beams for monitoring retransmissions of the downlink transmission is based at least in part on a set of measurements of the one or more reference signals.

7. The UE of claim 1, wherein the one or more processors are further configured to: The number of the one or more new beams is further selected based at least in part on the configuration of the UE.

8. The UE of claim 1, wherein the one or more processors are further configured to: Determine that the timing offset between transmitting the measurement report and transmitting the negative acceptance meets a timing threshold. Monitoring the one or more new beams to find retransmissions of the downlink transmission is based at least in part on determining that the timing offset meets the timing threshold.

9. The UE of claim 1, wherein the one or more processors are further configured to: Receive downlink control information messages that activate one or more new beams for monitoring retransmissions of the downlink transmission.

10. The UE of claim 1, wherein the one or more processors are configured to: when monitoring the one or more new beams in the candidate beam set to find retransmissions of the downlink transmission. After transmitting the negative acknowledgment, if no instruction is received from the base station regarding the activation of the one or more new beams, the system monitors the one or more new beams in the candidate beam set to look for retransmissions of the downlink transmission.

11. The UE of claim 1, wherein the one or more processors are further configured to: Retransmissions of the downlink transmission are received via at least one of the one or more new beams.

12. The UE of claim 11, wherein the one or more processors are further configured to: The transmission acknowledges the retransmission of the downlink transmission received via at least one of the one or more new beams.

13. The UE of claim 12, wherein the one or more processors are further configured to: At least one additional message is transmitted via at least one of the one or more new beams.

14. A wireless communication method performed by a user equipment (UE), comprising: Measurement reports are transmitted based at least in part on a set of measurements of one or more reference signals received using a set of candidate beams, wherein the measurement reports include a ranking of the candidate beams in the set of candidate beams; The transmission receives a negative acknowledgment for downlink transmissions scheduled for one or more beams in the candidate beam set. Select one or more new beams for monitoring retransmissions of the downlink transmission and based at least in part on the ranking; as well as Monitor the one or more new beams in the candidate beam set to look for the retransmission of the downlink transmission.

15. The method of claim 14, further comprising: Receive radio resource control (RRC) reconfiguration signaling including instructions regarding monitoring the candidate beam set to search for the one or more reference signals; The UE is configured to monitor the candidate beam set to find the one or more reference signals; as well as Transmit an indication that the UE is configured to monitor the candidate beam set in order to find the one or more reference signals.

16. The method of claim 15, further comprising: Measurements are obtained of the one or more reference signals received on the candidate beam set; as well as The ranking of the candidate beams in the candidate beam set is determined at least in part based on measurements of the one or more reference signals.

17. The method of claim 14, further comprising: The one or more beams for receiving the downlink transmission are selected, at least in part, based on a set of measurements of the one or more reference signals.

18. The method of claim 14, further comprising: The number of the one or more beams is further selected based at least in part on the configuration of the UE.

19. The method of claim 14, further comprising: The selection of the one or more new beams for monitoring retransmissions of the downlink transmission is based at least in part on a set of measurements of the one or more reference signals.

20. The method of claim 14, further comprising: The number of the one or more new beams is further selected based at least in part on the configuration of the UE.

21. The method of claim 14, further comprising: Determine that the timing offset between transmitting the measurement report and transmitting the negative acceptance meets a timing threshold. Monitoring the one or more new beams to find retransmissions of the downlink transmission is based at least in part on determining that the timing offset meets the timing threshold.

22. The method of claim 14, further comprising: Receive downlink control information messages that activate one or more new beams for monitoring retransmissions of the downlink transmission.

23. The method of claim 14, wherein monitoring the one or more new beams in the candidate beam set to find retransmissions of the downlink transmission comprises: After transmitting the negative acknowledgment, if no instruction is received from the base station regarding the activation of the one or more new beams, the system monitors the one or more new beams in the candidate beam set to look for retransmissions of the downlink transmission.

24. The method of claim 14, further comprising: Retransmissions of the downlink transmission are received via at least one of the one or more new beams.

25. The method of claim 24, further comprising: The transmission acknowledges the retransmission of the downlink transmission received via at least one of the one or more new beams.

26. The method of claim 25, further comprising: At least one additional message is transmitted via at least one of the one or more new beams.

27. A non-transient computer-readable medium storing an instruction set for wireless communication, the instruction set comprising: One or more instructions that, when executed by one or more processors of a user equipment (UE), cause the UE to perform the following operations: Measurement reports are transmitted based at least in part on a set of measurements of one or more reference signals received using a set of candidate beams, wherein the measurement reports include a ranking of the candidate beams in the set of candidate beams; The transmission receives a negative acknowledgment for downlink transmissions scheduled for one or more beams in the candidate beam set. Select one or more new beams for monitoring retransmissions of the downlink transmission and based at least in part on the ranking; as well as Monitor the one or more new beams in the candidate beam set to look for retransmissions of the downlink transmission.

28. The non-transient computer-readable medium of claim 27, wherein one or more instructions further cause the UE to: The one or more beams for receiving the downlink transmission are selected, at least in part, based on a set of measurements of the one or more reference signals.

29. A device for wireless communication, comprising: A means for transmitting a measurement report based at least in part on a set of measurements of one or more reference signals received using a set of candidate beams, wherein the measurement report includes a ranking of candidate beams in the set of candidate beams; A means for transmitting negative acknowledgments for downlink transmissions scheduled for one or more beams in the candidate beam set. A means for selecting one or more new beams for monitoring retransmissions of the downlink transmission and based at least in part on the ranking; as well as A means for monitoring one or more new beams in the candidate beam set to find retransmissions of the downlink transmission.

30. The apparatus of claim 29, further comprising: A means for selecting one or more beams for receiving the downlink transmission, based at least in part on a set of measurements of the one or more reference signals.

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