Determine beam candidates for sending beam failure recovery signals

Abstract

Methods, systems, and devices for wireless communications are described. A user equipment (UE) may identify a beam failure condition. The UE may determine whether a reference signal beam satisfies a beam strength threshold. The UE may transmit a beam failure recovery (BFR) signal using resources associated with the reference signal beam based at least in part on the result of the determination.

Description

[0001] Cross-references

[0002] This patent application claims priority to U.S. Patent Application No. 16 / 189,229, entitled “Determining Beam Candidates for Transmitting Beam Failure Recovery Signal,” filed by Sadiq et al. on November 13, 2018, and U.S. Provisional Patent Application No. 62 / 592,392, entitled “Determining Beam Candidates for Transmitting Beam Failure Recovery Signal,” filed by Sadiq et al. on November 29, 2017, each of which is assigned to the assignee of this application, and the entire contents of both applications are expressly incorporated herein by reference. Technical Field

[0003] The following relates generally to wireless communications, and more particularly, to determining beam candidates for transmitting beam failure recovery (BFR) signals. Background Art

[0004] Wireless communication systems are widely deployed to provide various types of communication content such as voice, video, packet data, messaging, broadcasting, etc. These systems may be able to support communication with multiple users by sharing available system resources (e.g., time, frequency, and power). Examples of such multiple access systems include fourth generation (4G) systems (such as long term evolution (LTE) systems, improved LTE (LTE-A) systems, or LTE-A Pro systems) and fifth generation (5G) systems (which may be referred to as new radio (NR) systems). These systems may use technologies such as code division multiple access (CDMA), time division multiple access (TDMA), frequency division multiple access (FDMA), orthogonal frequency division multiple access (OFDMA), or discrete Fourier transform spread spectrum OFDM (DFT-S-OFDM). A wireless multiple access communication system may include multiple base stations or network access nodes, each of which simultaneously supports communication for multiple communication devices (which may be further referred to as user equipment (UE)).

[0005] Wireless communication systems may operate in the millimeter wave (mmW) frequency range (e.g., 28 GHz, 40 GHz, 60 GHz, etc.). Wireless communication at these frequencies may be associated with increased signal attenuation (e.g., path loss), which may be affected by various factors, such as temperature, atmospheric pressure, diffraction, etc. Therefore, signal processing techniques (such as beamforming) may be used to coherently combine energy and overcome path losses at these frequencies. Due to the increased amount of path loss in mmW communication systems, transmissions from base stations and / or UEs may be beamformed. In addition, a receiving device may use beamforming techniques to configure an antenna and / or antenna array so that the transmission is received in a directional manner.

[0006] In some cases, a device can select a beam direction (e.g., a beam identification (ID)) for communicating with a network by selecting the strongest beam from a plurality of reference signals (RS) sent by a base station. For example, a base station may use various beams to send RSs (e.g., beamforming signals). The UE may monitor these RSs to identify "good" candidate beams to become active beams. One of the other uses for maintaining this set of candidate beams is to use these beams to send BFR signals. The BFR signal is typically triggered when certain criteria are met, such as when the estimated block error rate (BLER) of the control channel drops below a threshold. However, conventional techniques do not provide a mechanism for the UE to select the best candidate beam from the RSs for sending the BFR signal. Summary of the invention

[0007] The described technology relates to an improved method, system, device or apparatus that supports determining a beam candidate for sending a beam failure recovery (BFR) signal. In summary, the described technology provides criteria for a user equipment (UE) to use when selecting a candidate reference signal (RS) beam to be used to send a BFR signal. For example, the UE may identify or otherwise determine that it is operating in a beam failure condition, for example, one or more criteria associated with an active beam fail to meet a threshold. Accordingly, the UE may detect an RS beam sent from a base station. The RS beam may be associated with a synchronization signal (SS) beam, a physical broadcast channel (PBCH) beam, a channel state information RS (CSI-RS) beam, a beam refinement signal beam, etc. The UE may be configured with a beam strength threshold level, which generally defines a beam that is a suitable candidate for sending a BFR signal when the threshold is met. The UE may select from any RS beam that meets the beam strength threshold, and then use resources associated with the RS beam to send a BFR signal. Resources may include, but are not limited to, beam direction, beam shape, beam identifier (ID), etc. In the case that no RS beam among the detected RS beams satisfies the beam strength threshold, the UE may select any detected RS beam and / or may select the detected RS beam with the highest beam strength.

[0008] A method of wireless communication is described. The method may include: identifying a beam failure condition; determining whether a reference signal beam satisfies a beam strength threshold; and transmitting a BFR signal using resources associated with the reference signal beam based at least in part on a result of the determination.

[0009] An apparatus for wireless communication is described. The apparatus may include: means for identifying a beam failure condition; means for determining whether a reference signal beam satisfies a beam strength threshold; and means for transmitting a BFR signal using resources associated with the reference signal beam based at least in part on a result of the determination.

[0010] Another apparatus for wireless communication is described. The apparatus may include a processor, a memory in electronic communication with the processor, and instructions stored in the memory. The instructions may be operable to cause the processor to: identify a beam failure condition; determine whether a reference signal beam satisfies a beam strength threshold; and based at least in part on the result of the determination, use resources associated with the reference signal beam to send a BFR signal. In some examples, hardware (such as an antenna) may be configured to: based at least in part on the result of the determination, use resources associated with the reference signal beam to send a BFR signal.

[0011] A non-transitory computer-readable medium for wireless communication is described. The non-transitory computer-readable medium may include instructions operable to cause a processor to: identify a beam failure condition; determine whether a reference signal beam satisfies a beam strength threshold; and transmit a BFR signal using resources associated with the reference signal beam based at least in part on a result of the determination.

[0012] Some examples of methods, apparatuses, and non-transitory computer-readable media described herein may also include a process, feature, unit, or instruction for detecting a set of reference signal beams, and determining that the reference signal beams in the set fail to meet the beam strength threshold. Some examples of methods, apparatuses, and non-transitory computer-readable media described herein may also include a process, feature, unit, or instruction for selecting any reference signal beam from the detected set of reference signal beams as the reference signal beam.

[0013] Some examples of the methods, apparatuses, and non-transitory computer-readable media described herein may also include a process, feature, unit, or instruction for detecting a set of reference signal beams, and determining that the reference signal beams in the set fail to meet the beam strength threshold. Some examples of the methods, apparatuses, and non-transitory computer-readable media described herein may also include a process, feature, unit, or instruction for selecting a reference signal beam that may have the highest beam strength from the set of reference signal beams as the reference signal beam.

[0014] Some examples of the methods, apparatuses, and non-transitory computer-readable media described herein may also include processes, features, units, or instructions for performing the following operations: receiving a configuration message indicating the beam strength threshold.

[0015] In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, determining whether the reference signal beam satisfies the beam strength threshold may include determining that the reference signal beam may be received with a beam strength metric that satisfies the threshold.

[0016] In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, the beam strength metric includes one or more of: a reference signal received power (RSRP) metric, or a reference signal received quality (RSRQ) metric, a signal to interference plus noise ratio (SINR), an estimated block error rate (BLER), or a combination thereof.

[0017] Some examples of methods, apparatuses, and non-transitory computer-readable media described herein may also include a process, feature, unit, or instruction for detecting a set of reference signal beams, and determining that more than one of the reference signal beams in the set satisfies the beam strength threshold. Some examples of methods, apparatuses, and non-transitory computer-readable media described herein may also include a process, feature, unit, or instruction for selecting any of the more than one reference signal beams as the reference signal beam.

[0018] Some examples of the methods, apparatuses, and non-transitory computer-readable media described herein may also include a process, feature, unit, or instruction for detecting a set of reference signal beams, and determining that more than one of the reference signal beams in the set satisfies the beam strength threshold. Some examples of the methods, apparatuses, and non-transitory computer-readable media described herein may also include a process, feature, unit, or instruction for selecting a reference signal beam with the highest beam strength from the more than one reference signal beams as the reference signal beam. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1

[0013] Examples of systems for wireless communications that support determining beam candidates for transmitting BFR signals are shown in accordance with aspects of the present disclosure.

[0020] Figure 2

[0013] An example of a system for wireless communication that supports determining beam candidates for transmitting a BFR signal is shown in accordance with aspects of the present disclosure.

[0021] Figure 3 Examples of processes supporting determination of beam candidates for transmitting a BFR signal are shown according to aspects of the present disclosure.

[0022] Figures 4 to 6 A block diagram of a device that supports determining beam candidates for transmitting a BFR signal is shown in accordance with aspects of the present disclosure.

[0023] Figure 7 A block diagram of a system including a UE that supports determining beam candidates for transmitting a BFR signal is shown in accordance with aspects of the present disclosure.

[0024] Figures 8 to 10 A method for determining beam candidates for transmitting a BFR signal is shown in accordance with aspects of the present disclosure. DETAILED DESCRIPTION

[0025] Some wireless communication systems may operate in the millimeter wave (mmW) frequency range (e.g., 28 GHz, 40 GHz, 60 GHz, etc.). In some cases, wireless communication at these frequencies may be associated with increased signal attenuation (e.g., path loss), which may be affected by various factors, such as temperature, atmospheric pressure, diffraction, etc. Therefore, signal processing techniques such as beamforming (e.g., directional transmission) may be used to coherently combine energy in a particular beam direction and overcome path loss. In some cases, a device may select an active beam for communicating with a network by selecting the strongest beam from multiple candidate beams.

[0026] In mmW systems, various reference signals (RS) can be beamformed to meet a certain link budget (e.g., a calculation of the gains and losses associated with a transmitter and / or receiver when communicating over a medium). In particular, beamforming can be used to increase the strength or power of a wireless signal in a certain direction. A base station can use several antenna ports connected to an antenna subarray to form beams in various directions by appropriately weighting the amplitude and phase of independent antenna ports and signals. Thus, a base station can use beamforming to send RSs in multiple directions, for example, using different beam IDs. A user equipment (UE) can monitor some or all of the RSs to identify candidate beams for use as active beams for the mmW system.

[0027] The UE may experience a beam failure condition, such as when the UE determines that the estimated block error rate (BLER) of the control channel fails to meet a threshold. Accordingly, the UE may need to send a beam failure recovery (BFR) signal to identify a new active beam. However, conventional systems do not provide criteria for the UE to select a beam for transmission of a BFR signal.

[0028] Various aspects of the present disclosure are first described in the context of a wireless communication system. For example, a UE may determine that a beam failure condition has occurred. The UE may identify a beam direction from a detected RS beam that satisfies a beam strength threshold (e.g., satisfies a certain path loss or transmission power condition). The UE may then select a beam direction for sending a BFR signal by selecting one of the beam directions of the RS beam that satisfies the beam strength threshold. For example, if each RS beam satisfies the beam strength threshold, the UE may select any one of the RS beams. If no RS beam in the RS beam satisfies the beam strength threshold, the UE may select any detected RS beam, may select the detected RS beam with the highest beam strength, and so on, for transmission of the BFR signal. Accordingly, the UE may use resources associated with the RS beam (e.g., beam direction resources, beam shape resources, beam timing resources, etc.) to send a BFR signal.

[0029] Aspects of the present disclosure are further illustrated by and described with reference to apparatus diagrams, system diagrams, and flow diagrams related to determining beam candidates for transmitting BFR signals.

[0030] Figure 1 An example of a wireless communication system 100 is shown according to various aspects of the present disclosure. The wireless communication system 100 includes a base station 105, a UE 115, and a core network 130. In some examples, the wireless communication system 100 can be a long term evolution (LTE) network, an improved LTE (LTE-A) network, an LTE-A Pro network, or a new radio (NR) network. In some cases, the wireless communication system 100 can support enhanced broadband communication, ultra-reliable (e.g., mission-critical) communication, low-latency communication, or communication with low-cost and low-complexity devices.

[0031] The base station 105 may communicate wirelessly with the UE 115 via one or more base station antennas. The base station 105 described herein may include or may be referred to by those skilled in the art as a base transceiver station, a wireless base station, an access point, a wireless transceiver, a node B, an evolved node B (eNB), a next generation node B, or a giga node B (any of which may be referred to as a gNB), a home node B, a home evolved node B, or some other appropriate terminology. The wireless communication system 100 may include different types of base stations 105 (e.g., macro cell base stations or small cell base stations). The UE 115 described herein may be able to communicate with various types of base stations 105 and network devices (including macro eNBs, small cell eNBs, gNBs, relay base stations, etc.).

[0032] Each base station 105 may be associated with a particular geographic coverage area 110 in which communications with respective UEs 115 are supported. Each base station 105 may provide communications coverage for a respective geographic coverage area 110 via a communications link 125, and the communications link 125 between the base station 105 and the UE 115 may utilize one or more carriers. The communications link 125 shown in the wireless communication system 100 may include an uplink transmission from the UE 115 to the base station 105, or a downlink transmission from the base station 105 to the UE 115. Downlink transmissions may also be referred to as forward link transmissions, and uplink transmissions may also be referred to as reverse link transmissions.

[0033] The geographic coverage area 110 for the base station 105 can be divided into sectors, which constitute only a portion of the geographic coverage area 110, and each sector can be associated with a cell. For example, each base station 105 can provide communication coverage for a macro cell, a small cell, a hotspot, or other types of cells, or various combinations thereof. In some examples, the base station 105 can be mobile and, therefore, provide communication coverage for a mobile geographic coverage area 110. In some examples, different geographic coverage areas 110 associated with different technologies can overlap, and overlapping geographic coverage areas 110 associated with different technologies can be supported by the same base station 105 or different base stations 105. The wireless communication system 100 may include, for example, a heterogeneous LTE / LTE-A / LTE-A Pro or NR network, in which different types of base stations 105 provide coverage for each geographic coverage area 110.

[0034] The term "cell" refers to a logical communication entity used for communication with a base station 105 (e.g., on a carrier), and may be associated with an identifier (e.g., a physical cell identifier (PCID), a virtual cell identifier (VCID)) used to distinguish adjacent cells operating via the same or different carriers. In some examples, a carrier may support multiple cells, and different cells may be configured according to different protocol types (e.g., machine type communication (MTC), narrowband Internet of Things (NB-IoT), enhanced mobile broadband (eMBB), or other protocol types), which may provide access for different types of devices. In some cases, the term "cell" may refer to a portion of a geographic coverage area 110 (e.g., a sector) on which the logical entity operates.

[0035] UE 115 can be dispersed throughout the wireless communication system 100, and each UE 115 can be stationary or mobile. UE 115 can also be referred to as a mobile device, a wireless device, a remote device, a handheld device, or a user device, or some other appropriate term, wherein "device" can also be referred to as a unit, a station, a terminal, or a client. UE 115 can also be a personal electronic device, such as a cellular phone, a personal digital assistant (PDA), a tablet computer, a laptop computer, or a personal computer. In some examples, UE 115 can also refer to a wireless local loop (WLL) station, an Internet of Things (IoT) device, an Internet of Everything (IoE) device, or an MTC device, etc., which can be implemented in various items such as electrical appliances, vehicles, meters, etc.

[0036] Some UEs 115, such as MTC or IoT devices, may be low-cost or low-complexity devices and may provide automated communication between machines (e.g., via machine-to-machine (M2M) communication). M2M communication or MTC may refer to data communication technology that allows devices to communicate with each other or with a base station 105 without human intervention. In some examples, M2M communication or MTC may include communications from devices that integrate sensors or meters to measure or capture information and relay the information to a central server or application that may utilize the information or present the information to a person interacting with the program or application. Some UEs 115 may be designed to collect information or implement automated behavior of machines. Examples of applications for MTC devices include smart metering, inventory monitoring, water level monitoring, equipment monitoring, healthcare monitoring, wildlife monitoring, climate and geological event monitoring, fleet management and tracking, remote security sensing, physical access control, and transaction-based commercial billing.

[0037] Some UEs 115 may be configured to employ a reduced power consumption mode of operation, such as half-duplex communication (e.g., a mode that supports one-way communication via transmission or reception rather than simultaneous transmission and reception). In some examples, half-duplex communication may be performed at a reduced peak rate. Other power saving techniques for UE 115 include entering a power-saving "deep sleep" mode when not participating in active communications or operating on limited bandwidth (e.g., according to narrowband communications). In some cases, UE 115 may be designed to support critical functions (e.g., mission-critical functions), and the wireless communication system 100 may be configured to provide ultra-reliable communications for these functions.

[0038] In some cases, UE 115 may also be able to communicate directly with other UE 115 (e.g., using peer-to-peer (P2P) or device-to-device (D2D) protocols). One or more UE 115 in a group of UEs 115 utilizing D2D communication may be within the geographic coverage area 110 of the base station 105. Other UEs 115 in such a group may be outside the geographic coverage area 110 of the base station 105, or otherwise unable to receive transmissions from the base station 105. In some cases, multiple groups of UEs 115 communicating via D2D communication may utilize a one-to-many (1:M) system, wherein each UE 115 transmits to each other UE 115 in the group. In some cases, the base station 105 facilitates the scheduling of resources for D2D communication. In other cases, D2D communication is performed between UEs 115 without involving the base station 105.

[0039] The base stations 105 may communicate with the core network 130 and with each other. For example, the base stations 105 may interface with the core network 130 via a backhaul link 132 (e.g., via S1 or other interface). The base stations 105 may communicate with each other directly (e.g., directly between the base stations 105) or indirectly (e.g., via the core network 130) over a backhaul link 134 (e.g., via X2 or other interface).

[0040] The core network 130 may provide user authentication, access authorization, tracking, Internet Protocol (IP) connections, and other access, routing or mobility functions. The core network 130 may be an evolved packet core (EPC), which may include at least one mobility management entity (MME), at least one serving gateway (S-GW), and at least one packet data network (PDN) gateway (P-GW). The MME may manage non-access stratum (e.g., control plane) functions such as mobility, authentication, and bearer management for UEs 115 served by base stations 105 associated with the EPC. User IP packets may be transmitted through the S-GW, which itself may be connected to the P-GW. The P-GW may provide IP address allocation and other functions. The P-GW may be connected to network operator IP services. Operator IP services may include access to the Internet, intranet, IP multimedia subsystem (IMS), or packet switched (PS) streaming services.

[0041] At least some of the network devices, such as the base station 105, may include subcomponents such as access network entities, which may be examples of access node controllers (ANCs). Each access network entity may communicate with the UE 115 through multiple other access network transmission entities, which may be referred to as radio heads, smart radio heads, or transmit / receive points (TRPs). In some configurations, the various functions of each access network entity or base station 105 may be distributed across various network devices (e.g., radio heads and access network controllers) or merged into a single network device (e.g., base station 105).

[0042] The wireless communication system 100 can operate using one or more frequency bands, typically in the range of 300 MHz to 300 GHz. Typically, the region from 300 MHz to 3 GHz is referred to as the ultra-high frequency (UHF) region or decimeter band because the wavelength ranges from approximately one decimeter to one meter in length. UHF waves may be blocked or redirected by buildings and environmental features. However, the waves may be sufficient to penetrate the structure for macro cells to provide services to UEs 115 located indoors. Transmission of UHF waves may be associated with smaller antennas and shorter distances (e.g., less than 100 km) compared to transmission of smaller frequencies and longer waves using the high frequency (HF) or very high frequency (VHF) portion of the spectrum below 300 MHz.

[0043] The wireless communication system 100 may also operate in a Super High Frequency (SHF) region using a frequency band from 3 GHz to 30 GHz (also referred to as a centimeter band). The SHF region includes frequency bands such as the 5 GHz Industrial, Scientific and Medical (ISM) band, which may be opportunistically used by devices that can tolerate interference from other users.

[0044] The wireless communication system 100 may also operate in the extremely high frequency (EHF) region of the spectrum (e.g., from 30 GHz to 300 GHz), also referred to as the millimeter band. In some examples, the wireless communication system 100 may support millimeter wave (mmW) communications between the UE 115 and the base station 105, and the EHF antennas of the corresponding devices may be even smaller and more closely spaced than the UHF antennas. In some cases, this may facilitate the use of antenna arrays within the UE 115. However, the propagation of EHF transmissions may be subject to even greater atmospheric attenuation and shorter distances than SHF or UHF transmissions. The technology disclosed herein may be employed across transmissions using one or more different frequency regions, and the designated use of frequency bands across these frequency regions may differ according to the country or administrative body.

[0045] In some cases, the wireless communication system 100 can utilize both licensed and unlicensed radio frequency spectrum bands. For example, the wireless communication system 100 can adopt license assisted access (LAA), LTE unlicensed (LTE-U) wireless access technology, or NR technology in an unlicensed band (such as a 5GHz ISM band). When operating in an unlicensed radio frequency spectrum band, wireless devices (such as base stations 105 and UE 115) can use a listen-before-talk (LBT) process to ensure that the frequency channel is idle before sending data. In some cases, operations in unlicensed bands can be based on a CA configuration of a CC operating in a licensed band (e.g., LAA). Operations in unlicensed spectrum can include downlink transmissions, uplink transmissions, peer-to-peer transmissions, or a combination of these. Duplexing in unlicensed spectrum can be based on frequency division duplexing (FDD), time division duplexing (TDD), or a combination of the two.

[0046] In some examples, the base station 105 or the UE 115 may be equipped with multiple antennas, which may be used to employ techniques such as transmit diversity, receive diversity, multiple-input multiple-output (MIMO) communications, or beamforming. For example, the wireless communication system 100 may use a transmission scheme between a transmitting device (e.g., a base station 105) and a receiving device (e.g., a UE 115), wherein the transmitting device is equipped with multiple antennas and the receiving device is equipped with one or more antennas. MIMO communications may employ multipath signal propagation to improve spectral efficiency by transmitting or receiving multiple signals (which may be referred to as spatial multiplexing) via different spatial layers. For example, a transmitting device may transmit multiple signals via different antennas or different combinations of antennas. Similarly, a receiving device may receive multiple signals via different antennas or different combinations of antennas. Each of the multiple signals may be referred to as a separate spatial stream and may carry bits associated with the same data stream (e.g., the same codeword) or different data streams. Different spatial layers may be associated with different antenna ports for channel measurement and reporting. MIMO technology includes single-user MIMO (SU-MIMO) (where multiple spatial layers are sent to the same receiving device) and multi-user MIMO (MU-MIMO) (where multiple spatial layers are sent to multiple devices).

[0047] Beamforming (which may also be referred to as spatial filtering, directional transmission, or directional reception) is a signal processing technique that can be used at a transmitting device or a receiving device (e.g., a base station 105 or a UE 115) to shape or direct an antenna beam (e.g., a transmit beam or a receive beam) along a spatial path between the transmitting device and the receiving device. Beamforming can be achieved by combining signals transmitted via antenna elements of an antenna array so that signals propagating at a particular orientation relative to the antenna array experience constructive interference, while other signals experience destructive interference. Adjustments to signals transmitted via antenna elements may include the transmitting device or the receiving device applying certain amplitude and phase offsets to signals carried via each of the antenna elements associated with the device. Adjustments associated with each of the antenna elements may be defined by a set of beamforming weights associated with a particular orientation (e.g., relative to the antenna array of the transmitting device or the receiving device, or relative to some other orientation).

[0048] In one example, the base station 105 may use multiple antennas or antenna arrays to perform beamforming operations for directional communication with the UE 115. For example, the base station 105 may send some signals (e.g., synchronization signals, reference signals, beam selection signals, or other control signals) multiple times in different directions, and the some signals may include signals sent according to different beamforming weight sets associated with different transmission directions. Transmissions in different beam directions may be used to identify (e.g., by the base station 105 or a receiving device (e.g., UE 115)) a beam direction for subsequent transmission and / or reception by the base station 105. The base station 105 may send some signals (such as data signals associated with a specific receiving device) in a single beam direction (e.g., a direction associated with a receiving device (e.g., UE 115)). In some examples, the beam direction associated with transmissions along a single beam direction may be determined at least in part based on signals sent in different beam directions. For example, UE 115 may receive one or more of the signals sent by base station 105 in different directions, and UE 115 may report an indication of the signal received by base station 105 having the highest signal quality or otherwise acceptable signal quality to base station 105. Although these techniques are described with reference to signals sent by base station 105 in one or more directions, UE 115 may employ similar techniques to send signals multiple times in different directions (e.g., to identify a beam direction for subsequent transmission or reception by UE 115) or to send signals in a single direction (e.g., to send data to a receiving device).

[0049] When receiving various signals (such as synchronization signals, reference signals, beam selection signals, or other control signals) from base station 105, a receiving device (e.g., UE 115, which may be an example of a mmW receiving device) may try multiple receive beams. For example, the receiving device may try multiple receive directions by receiving via different antenna subarrays, by processing received signals according to different antenna subarrays, by receiving according to different sets of receive beamforming weights applied to signals received at multiple antenna elements of an antenna array, or by processing received signals according to different sets of receive beamforming weights applied to signals received at multiple antenna elements of an antenna array (any of which may be referred to as "listening" according to different receive beams or receive directions). In some examples, the receiving device may use a single receive beam to receive along a single beam direction (e.g., when receiving a data signal). A single receive beam can be aligned on a beam direction determined based at least in part on listening according to different receive beam directions (e.g., a beam direction determined to have the highest signal strength, the highest signal-to-noise ratio, or otherwise acceptable signal quality based at least in part on listening according to multiple beam directions).

[0050] In some cases, the antennas of a base station 105 or a UE 115 may be located within one or more antenna arrays that may support MIMO operations or transmit or receive beamforming. For example, one or more base station antennas or antenna arrays may be co-located at an antenna assembly, such as an antenna tower. In some cases, the antennas or antenna arrays associated with a base station 105 may be located at different geographic locations. A base station 105 may have an antenna array having multiple rows and columns of antenna ports that the base station 105 may use to support beamforming for communications with a UE 115. Likewise, a UE 115 may have one or more antenna arrays that may support various MIMO or beamforming operations.

[0051] In some cases, the wireless communication system 100 may be a packet-based network that operates according to a layered protocol stack. In the user plane, the communication at the bearer or packet data convergence protocol (PDCP) layer may be IP-based. In some cases, the radio link control (RLC) layer may perform packet segmentation and reassembly to communicate on a logical channel. The medium access control (MAC) layer may perform priority processing and multiplexing of logical channels to transport channels. The MAC layer may also use a hybrid automatic repeat request (HARQ) to provide retransmission at the MAC layer to improve link efficiency. In the control plane, the radio resource control (RRC) protocol layer may provide the establishment, configuration and maintenance of an RRC connection (which supports a radio bearer for user plane data) between the UE 115 and the base station 105 or the core network 130. At the physical (PHY) layer, a transport channel may be mapped to a physical channel.

[0052] In some cases, UE 115 and base station 105 can support retransmission of data to increase the possibility of data being successfully received. HARQ feedback is a technique to increase the possibility of data being correctly received on communication link 125. HARQ can include a combination of error detection (e.g., using cyclic redundancy check (CRC)), forward error correction (FEC) and retransmission (e.g., automatic repeat request (ARQ)). HARQ can improve the throughput at the MAC layer under poor wireless conditions (e.g., signal and noise conditions). In some cases, a wireless device can support same-slot HARQ feedback, wherein the device can provide HARQ feedback for data received in previous symbols in the slot in a specific slot. In other cases, the device can provide HARQ feedback in subsequent slots or according to some other time interval.

[0053] The basic time unit (eg, it can be referred to as T s =1 / 30,720,000 seconds). The time intervals of communication resources can be organized according to radio frames each having a duration of 10 milliseconds (ms), where the frame period can be represented as T f =307,200T s. A radio frame may be identified by a system frame number (SFN) ranging from 0 to 1023. Each frame may include 10 subframes numbered from 0 to 9, and each subframe may have a duration of 1 ms. A subframe may be further divided into 2 slots, each slot having a duration of 0.5 ms, and each slot may contain 6 or 7 modulation symbol periods (e.g., depending on the length of a cyclic prefix added in front of each symbol period). Excluding the cyclic prefix, each symbol period may contain 2048 sampling periods. In some cases, a subframe may be the minimum scheduling unit of the wireless communication system 100 and may be referred to as a transmission time interval (TTI). In other cases, the minimum scheduling unit of the wireless communication system 100 may be shorter than a subframe or may be dynamically selected (e.g., in a burst of a shortened TTI (sTTI) or in a component carrier selected to use sTTI).

[0054] In some wireless communication systems, a time slot may be further divided into a plurality of micro-slots comprising one or more symbols. In some instances, a symbol of a micro-slot or a micro-slot may be a minimum scheduling unit. Each symbol may vary in duration according to, for example, a subcarrier spacing or a frequency band of operation. In addition, some wireless communication systems may implement time slot aggregation, wherein a plurality of time slots or micro-slots are aggregated together and used for communication between a UE 115 and a base station 105.

[0055] The term "carrier" refers to a set of radio frequency spectrum resources having a defined physical layer structure for supporting communications on the communication link 125. For example, a carrier of the communication link 125 may include a portion of a radio frequency spectrum band that operates according to a physical layer channel for a given wireless access technology. Each physical layer channel may carry user data, control information, or other signaling. A carrier may be associated with a predefined frequency channel (e.g., an E-UTRA Absolute Radio Frequency Channel Number (EARFCN)) and may be placed according to a channel grid so as to be discovered by a UE 115. A carrier may be a downlink or an uplink (e.g., in FDD mode), or may be configured to carry downlink and uplink communications (e.g., in TDD mode). In some examples, a signal waveform sent on a carrier may be composed of multiple subcarriers (e.g., using a multi-carrier modulation (MCM) technique such as OFDM or DFT-s-OFDM).

[0056] The organization structure of the carrier may be different for different radio access technologies (e.g., LTE, LTE-A, LTE-A PRO, NR, etc.). For example, communications on a carrier may be organized according to TTIs or time slots, each of which may include user data and control information or signaling for supporting decoding of the user data. A carrier may also include dedicated acquisition signaling (e.g., synchronization signals or system information, etc.) and control signaling for coordinating operations for the carrier. In some examples (e.g., in a carrier aggregation configuration), a carrier may also have acquisition signaling or control signaling for coordinating operations for other carriers.

[0057] Physical channels may be multiplexed on a carrier according to various techniques. For example, a time division multiplexing (TDM) technique, a frequency division multiplexing (FDM) technique, or a hybrid TDM-FDM technique may be used to multiplex a physical control channel and a physical data channel on a downlink carrier. In some examples, the control information sent in the physical control channel may be distributed in a cascaded manner between different control regions (e.g., between a common control region or common search space and one or more UE-specific control regions or UE-specific search spaces).

[0058] A carrier may be associated with a particular bandwidth of radio frequency spectrum, and in some examples, the carrier bandwidth may be referred to as the "system bandwidth" of the carrier or wireless communication system 100. For example, the carrier bandwidth may be one of a plurality of predetermined bandwidths for a carrier of a particular radio access technology (e.g., 1.4, 3, 5, 10, 15, 20, 40, or 80 MHz). In some examples, each served UE 115 may be configured to operate on part or all of the bandwidth of the carrier bandwidth. In other examples, some UEs 115 may be configured to operate using a narrowband protocol type associated with a predefined portion or range (e.g., a set of subcarriers or RBs) within a carrier (e.g., an "in-band" deployment of a narrowband protocol type).

[0059] In a system using MCM technology, a resource element may consist of a symbol period (e.g., the duration of a modulation symbol) and a subcarrier, where the symbol period and the subcarrier spacing are inversely proportional. The number of bits carried by each resource element may depend on the modulation scheme (e.g., the order of the modulation scheme). Therefore, the more resource elements received by UE 115 and the higher the order of the modulation scheme, the higher the data rate for UE 115 can be. In a MIMO system, wireless communication resources may refer to a combination of radio frequency spectrum resources, time resources, and space resources (e.g., space layers), and the use of multiple space layers may further increase the data rate for communication with UE 115.

[0060] A device of the wireless communication system 100 (e.g., a base station 105 or a UE 115) may have a hardware configuration that supports communication on a specific carrier bandwidth, or may be configurable to support communication on one of a set of carrier bandwidths. In some examples, the wireless communication system 100 may include a base station 105 and / or a UE that is capable of supporting simultaneous communication via carriers associated with more than one different carrier bandwidths.

[0061] The wireless communication system 100 may support communication with the UE 115 on multiple cells or carriers (a feature that may be referred to as carrier aggregation or multi-carrier operation). Depending on the carrier aggregation configuration, the UE 115 may be configured with multiple downlink CCs and one or more uplink CCs. Carrier aggregation may be used with both FDD component carriers and TDD component carriers.

[0062] In some cases, the wireless communication system 100 can utilize an enhanced component carrier (eCC). An eCC can be characterized by one or more features including: a wider carrier or frequency channel bandwidth, a shorter symbol duration, a shorter TTI duration, or a modified control channel configuration. In some cases, an eCC can be associated with a carrier aggregation configuration or a dual connectivity configuration (e.g., when multiple serving cells have suboptimal or non-ideal backhaul links). An eCC can also be configured for use in an unlicensed spectrum or a shared spectrum (e.g., where more than one operator is allowed to use the spectrum). An eCC characterized by a wide carrier bandwidth can include one or more segments that can be utilized by a UE 115 that is unable to monitor the entire carrier bandwidth or is otherwise configured to use a limited carrier bandwidth (e.g., to save power).

[0063] In some cases, an eCC may utilize a different symbol duration than other CCs, which may include using a reduced symbol duration compared to the symbol duration of other CCs. A shorter symbol duration may be associated with an increased spacing between adjacent subcarriers. A device utilizing an eCC (e.g., a UE 115 or a base station 105) may transmit a wideband signal (e.g., according to a frequency channel or carrier bandwidth of 20, 40, 60, 80 MHz, etc.) with a reduced symbol duration (e.g., 16.67 microseconds). A TTI in an eCC may consist of one or more symbol periods. In some cases, the TTI duration (i.e., the number of symbol periods in a TTI) may be variable.

[0064] Wireless communication systems (such as NR systems) can utilize any combination of licensed, shared, and unlicensed spectrum bands. The flexibility of eCC symbol duration and subcarrier spacing can allow eCC to be used across multiple spectrums. In some examples, NR shared spectrum can improve spectrum utilization and spectrum efficiency, especially through dynamic vertical (e.g., across frequency) and horizontal (e.g., across time) sharing of resources.

[0065] In some aspects, UE 115 may identify a beam failure condition. UE 115 may determine whether a reference signal beam satisfies a beam strength threshold. UE 115 may transmit a BFR signal using resources associated with the reference signal beam based at least in part on the result of the determination.

[0066] Figure 2 An example of a wireless communication system 200 that supports determining beam candidates for transmitting a BFR signal is shown according to various aspects of the present disclosure. In some examples, the wireless communication system 200 can implement aspects of the wireless communication system 100. The wireless communication system 200 can include a base station 205 and a UE 215, which can be examples of corresponding devices described herein.

[0067] Typically, the base station 205 may transmit multiple RSs to UEs located within the coverage area of ​​the base station 205. RSs may be transmitted using RS beams 210a-210d. Each RS beam 210 may have an associated beam ID, beam direction, beam symbol, etc. Examples of RSs may include synchronization signals (e.g., primary synchronization signal (PSS), secondary synchronization signal (SSS), etc.), channel performance reference signals (e.g., channel state information reference signal (CSI-RS), demodulation reference signal (DMRS)), broadcast beams (e.g., physical channel broadcast channel (PBCH) beams), beam refinement beams, or any combination of such RSs.

[0068] In some cases, the base station 205 can use interleaved directional RS beams 210 to reduce the time before the UE 205 receives an acceptable beam. In some cases, groups of interleaved RS beams 210 can be sent at different time periods. In some cases, different antenna ports can be used to send the interleaved directional RS beams 210. In some cases, a scanning mode that does not use interleaved RS beams 210 can be used.

[0069] The UE 215 may identify a beam failure condition. The beam failure condition may be identified based on the UE 215 determining that a metric associated with an active beam (e.g., a beam used for ongoing communications) has fallen below a threshold. For example, the UE 215 may determine that an estimated BLER of a control channel has fallen below a threshold, and this may trigger a beam failure condition.

[0070] The UE 215 may monitor the RS beams 210 transmitted from the base station 205 over a period of time, for example, the UE 215 may store information associated with any RS beams 210 detected over a period of time. For example, for each detected RS beam 210, the UE 215 may determine and / or store a beam strength metric, such as RSRP, RSRQ, SINR, estimated BLER, etc. Accordingly, the UE 215 may maintain a list of candidate beams that are suitable (e.g., satisfying a beam strength threshold) for transmitting a BFR signal, for example, before identifying any beam failure conditions.

[0071] The UE 215 may be configured with a beam strength threshold to be used when selecting resources associated with the RS beam 210 to be used to transmit the BFR signal. For example, the base station 205 may send a configuration message indicating the beam strength threshold to the UE 215. In general, the beam strength threshold may be used by the UE 215 as a criterion when selecting resources associated with the RS beam 210 to be used to transmit the BFR signal. The BFR signal generally provides a trigger mechanism by which the base station 205 and the UE 215 perform a beam recovery procedure to identify a new active beam.

[0072] In some aspects, the beam strength threshold can be different from a threshold used to identify a beam failure condition (e.g., such as an estimated BLER threshold). For example, the UE 215 can use a beam strength threshold (e.g., RSRP, RSRQ, SINR, etc.) that is different from the estimated BLER threshold configured by the network when selecting the best candidate beam to be used for BFR signal transmission. Broadly speaking, this can support the UE 215 in identifying any candidate beam that may be suitable for transmission of the BFR signal, thereby improving the chance that the UE 215 can recover from a beam failure condition. In some aspects, it can be simpler for the UE 215 to calculate the beam strength threshold than to calculate the threshold used to identify a beam failure condition.

[0073] The UE 215 may determine whether any RS beam 210 satisfies a beam strength threshold. Broadly speaking, if the UE 215 detects one or more RS beams 210 having a beam strength that satisfies a threshold, the UE 215 may transmit a BFR signal using a beam corresponding to any one of those RS beams 210. For example, the UE 215 may use beam strength metrics (e.g., RSRP, RSRQ, SINR, BLER, etc.) from the RS beams 210 to identify which RS beams 210 satisfy the threshold. As a non-limiting example, RS beams 210-a and 210-b may have beam strength metrics that fail to meet the threshold, and RS beams 210-c and 210-d may have beam strength metrics that meet the threshold. Between RS beams 210-c and 210-d, RS beam 210-c may have the highest beam strength.

[0074] In some aspects, the UE 215 may therefore detect a set of RS beams 210 and determine that more than one RS beam 210 in the set (e.g., RS beams 210-c and 210-d) meet the beam strength threshold. As a response option, the UE 215 may select any one of the more than one RS beams 210 (e.g., either one of the RS beams 210-c and 210-d) as the RS beam 210. As another response option, the UE 215 may select the RS beam 210 (e.g., RS beam 210-c) having the highest beam strength from the more than one RS beams 210 as the RS beam 210. Accordingly, the UE 215 may use resources associated with the RS beam 210 (e.g., RS beam 210-c) to send a BFR signal.

[0075] However, in some cases, the UE 215 may not detect any RS beam 210 that meets the threshold. For example, when RS beams 210-c and 210-d are transmitted, the UE 215 may be tuned away from the base station 205, but when RS beams 210-a and 210-b are transmitted, the UE 215 may be tuned to the base station 205. In this case, the UE 215 may select any detected RS beam 210 (e.g., RS beam 210-a or 210-b) to transmit the BFR signal, or may select the detected RS beam 210 with the highest beam strength (e.g., RS beam 210-b) to transmit the BFR signal.

[0076] In some aspects, this may include the UE 215 detecting a set of RS beams 210 (e.g., RS beams 210-a and 210-b), and determining that an RS beam in the set fails to meet a beam strength threshold. As a response option, the UE 215 may select any RS beam 210 from the detected set of RS beams 210 as the RS beam 210. As another response option, the UE 215 may select an RS beam 210 with the highest beam strength from the set of RS beams 210 as the RS beam.

[0077] In some aspects, the UE 215 may identify multiple beam directions (e.g., RS beam 210) that satisfy path loss or transmission power conditions. The UE 215 may then select a beam direction for sending a BFR signal by selecting one of the acceptable beam directions that satisfies additional criteria (e.g., a beam strength threshold). In some examples, the conditions may be in a hierarchical relationship or a peer-to-peer relationship, depending on the system design. For example, if each beam direction is associated with a defined time slot, a beam direction may be selected to reduce the time before a BFR signal may be sent. The transmission power may be selected based on a target received power and a path loss for the selected beam direction. In some cases, if the sum of the path loss for the beam direction and the target received power exceeds the maximum transmission power by more than a predetermined amount, the beam direction will not be used to send a BFR signal. In some cases, if a response to the BFR is not received, a different beam direction may be selected, the transmission power may be increased, or both operations may be performed.

[0078] In some aspects, the UE 215 may receive the directional RS beam 210 and identify multiple candidate beam directions for transmitting a BFR signal based on the transmission power condition. In general, the BFR signal transmission power P may be determined according to the following equation: BFR :

[0079] P BFR =min{P CMAX(i) ,Preamble_Received_Target_Power+PL}[dBm], where, P CMAX(i) is the configured UE transmit power defined for a given subframe with index i, PL is a downlink path loss estimate (e.g., calculated by UE 215 based on the received power of a beamforming reference signal (BRS) associated with a given beam), and Preamble_Received_Target_Power is a parameter that the base station 205 can set to indicate the power at which it wants to receive BFR signals. The power transmission parameter can be set by the base station 205 using a system information message (e.g., in a system information block (SIB) transmission).

[0080] In some cases, a beam may be identified as a suitable candidate if the desired transmit power is less than the maximum transmit power:

[0081] Preamble_Receive_Target_Power+PL≤P CMAX(i)

[0082] Accordingly, a beam direction can be considered inappropriate or restricted if the path loss corresponding to that direction satisfies the following conditions:

[0083] Preamble_Receive_Target_Power+PL>P CMAX(i)

[0084] In other cases, different parameters may be used to select candidate beam directions. However, the transmission power may still be limited by the maximum transmission power P CMAX(i) In some cases, the UE 215 may identify a suitable beam direction based on the power gap parameter α according to the following equation:

[0085] Preamble_Receive_Target_Power+PL≤P CMAX(i) +α

[0086] Accordingly, a beam direction can be considered inappropriate or restricted if the path loss corresponding to that direction satisfies the following conditions:

[0087]

[0088] That is, if the sum of the target received power and the path loss for the beam direction exceeds the maximum transmit power and is less than the power gap parameter, the UE 215 can identify the beam direction as a candidate. Therefore, the UE 215 can identify multiple candidate beam directions. Then, the UE 215 can select a beam direction and use the resources associated with the selected beam direction to send a BFR signal. In some cases, the beam direction can be selected so that the UE 215 can send a BFR signal during the next available transmission opportunity. In some cases, the UE 215 can select a beam based on a channel metric for a candidate beam direction (e.g., a direction with the lowest path loss or a high signal-to-noise ratio). In some cases, the beam direction with the highest received beam strength can be selected. In other cases, the beam direction can be randomly selected from the candidate beams. In some examples, depending on the system design, the conditions can be in a hierarchical relationship or a peer relationship.

[0089] In some cases, P BFRThe initial transmit power for the BFR signal may be indicated. That is, the UE 215 may use P BFR To initially send a BFR signal, however, if it does not receive a BFR response message, it can ramp up the transmit power in subsequent BFR signal transmissions. That is, in some cases, P BFR Can be less than the maximum transmit power P CMAX(i) .

[0090] Thus, for example, UE 215 may use a given beam direction I with P BFR In the next subframe, UE 215 sends the initial transmission with P BFR +β, where the parameter β represents the amount of power increase. In some cases, UE 215 may continue to use beam I even if the current preferred beam is different (e.g., beam J). In another example, UE 215 uses beam I with P BFR Then, in the next subframe, UE 215 may transmit using the current preferred beam (beam J) at the same power level. In another example, UE 215 may transmit using beam I at P BFR Initially transmit, and then in the next subframe, use the new preferred beam J to transmit with P BFR In some cases, the base station 205 may indicate in the configuration message the process for selecting candidate beams, transmit power, and power ramping.

[0091] In some examples, UE 215 may ramp up transmit power in some BFR signal retransmissions and select a preferred beam in other BFR signal retransmissions. BFR If the UE 215 initially transmits a BFR signal with a power level of P and selects beam I for its transmission time, and the transmission fails, then in the next transmission opportunity, the UE 215 may use a power level of P BFR +β and use the transmission time corresponding to the same beam (e.g., beam I) for transmission. If the BFR signal transmission fails, then in the next transmission opportunity, UE 215 may use power P BFR +β is transmitted, and a transmission time corresponding to the new preferred beam (e.g., beam J) is selected. If the second BFR signal transmission fails, the UE 215 may use power level P in the next transmission opportunity. BFR +2β is used for transmission, and the transmission time corresponding to the previous preferred beam J is selected. If the third BFR signal transmission fails, in the next transmission opportunity, the UE 215 may use another preferred beam (e.g., beam K) to transmit at P BFR +2β for sending.

[0092] In the case of using interleaved scanning, the base station 205 can configure a first set of beam directions for the RS to be broadcast to the UE 215. The base station 205 can perform the transmission by beamforming using interleaved scanning. The base station 205 can send a first plurality of RS beams 210 on a first symbol period of a subframe, and a second plurality of RS beams 210 on a second symbol period of a subframe. For the first plurality of RS beams 210, the base station 205 can send RS beams 210 in a first beam set (e.g., beams 210-a and 210-c), where the first beam set corresponds to a portion of the first direction set. For the second symbol period, the base station 205 can send a second plurality of RS beams 210 in a second beam set (e.g., beams 210-b and 210-d), where the second beam set can correspond to a portion of the second beam direction set. The second beam direction set can be interleaved with the first direction set. For example, beam 210 - b may be spatially located between beam 210 - a and beam 210 - c , and beam 210 - c may be spatially located between beam 210 - b and beam 210 - d .

[0093] Therefore, in some cases, the first beam set may include two interleaved beam sets. In this way, the first beam set and the second beam set may be further extended to cover a larger area. Figure 2In the example, the first beam set may include two beams (RS beams 210-a and 210-c), and the second beam set may include two beams (RS beams 210-b and 210-d). In other examples, more beams may be included in the first beam set and the second beam set. In some examples, three or more beam sets may be used. For example, the base station 205 may support eight antenna ports for beamforming, and the first beam set may include eight RS beams 210 spatially interleaved with the second beam set, and the second beam set may also include eight RS beams 210. Each of beams 210-a and 210-c can be alternated with each of beams 210-b and 210-d such that a first beam in a first set of RS beams 210-a and 210-c can be oriented at a first angle, a first beam in a second set of beams 210-b and 210-d can be oriented at a second angle adjacent to the first beam in the first set of RS beams 210-a and 210-c, followed by a second beam in the first set of beams 210-a and 210-c at the next radial angle oriented at a third angle adjacent to the first beam in the second set of beams 210-b and 210-d, followed by a second beam in the second set of beams 210-b and 210-d at the next radial angle oriented at a fourth angle adjacent to the second beam in the first set of beams 210-a and 210-c, and so on. As such, the first set of beams can have an angular spread about a vertical axis of the base station 205 that is approximately the same as an angular spread of the second set of beams about the vertical axis of the base station 205. For example, each of the first set of beams and the second set of beams can have an angular spread in a range of approximately 30° to 90°, and in some cases, the angular spread can be approximately 45°.

[0094] In other examples, the first set of beams and the second set of beams may be interleaved according to other arrangements or patterns that are not strictly alternating, for example, two beams 210-a and 210-c may be followed by two beams 210-b and 210-d, followed by two beams 210-a and 210-c, followed by two beams 210-b and 210-d, and so on.

[0095] Other examples can include interleaving beams in a first beam set with beams in a second beam set in an angular direction about a vertical axis of base station 205 and in a vertical direction where vertical beamforming can be used. For example, RS beam 210-d can be oriented above RS beam 210-b at a first angular direction about a vertical axis of base station 205 (e.g., oriented vertically above RS beam 210-b), while RS beam 210-c can be oriented above beam 210-a at a second angular direction about the vertical axis of base station 205, the second angular direction being adjacent to the first angular direction. More than two beam sets (e.g., three or more beam sets) can be spatially interleaved according to other patterns to reduce latency.

[0096] UE 215 can decode RS beams 210 received from base station 205. UE 215 can receive a first plurality of RS beams 210 (e.g., beams 210-a and 210-c) on a first set of directions. However, due to the low gain corresponding to the first set of directions, the received power of the first plurality of RS beams 210 may be weak. UE 215 may still be able to decode RS beams 210-a and 210-c, and then determine a frequency set (e.g., for BFR signals) for transmission to base station 205. In addition, UE 215 can receive a second plurality of RS (e.g., beams 210-b and 210-d) on a second set of directions. The RS received on the second set of directions may have a stronger received power relative to the RS received on the first set of directions. This may be due to the higher gain corresponding to the second set of directions. Then, UE 215 can determine the resources allocated for the second symbol period for BFR signal transmission. Subsequently, UE 215 can send a BFR signal. A BFR signal may be sent in the direction of the received RS in the second symbol period.

[0097] In other examples, the base station 205 may monitor beams from the UE 215 in a first set of directions and may monitor beams from the UE 215 in a second set of directions, wherein the second set of beam directions may be spatially interleaved with the first set of beam directions. For example, the monitoring may include the base station 205 changing antenna parameters (e.g., phase and amplitude) for multiple antenna elements in an antenna array to listen to signals from a UE that may also have implemented beamforming to transmit to the base station 205 at a specific time and frequency. In some examples, the UE 215 may transmit a BFR signal that may be part of a beam recovery process. Similar to the transmission of beams in a first set of directions and beams in a second set of directions, the UE 215 may monitor in a direction in which the beams are spatially interleaved in an angular direction about a vertical axis of the base station 205 (e.g., by alternating or according to another pattern). In other examples, the first set of beams and the second set of beams may also be interleaved vertically (e.g., alternating or according to another pattern).

[0098] Thus, in some examples, as further described herein, UE 215 may have received one or more RS beams 210 from base station 205, and sent a BFR signal or other signaling to base station 205 during a subframe. As described herein, base station 205 may use a first beam set to transmit or monitor in a first symbol period, and may use a second beam set to transmit or monitor in a second symbol period. In some cases, the symbol period may be an adjacent symbol period in a subframe (e.g., a synchronization subframe for transmission or a random access subframe for monitoring). For example, as described herein, the first symbol of a subframe to be transmitted on a first beam set may be adjacent to the second symbol of a subframe to be transmitted using a second beam set. In other examples, the first beam set may be used to transmit RS beam 210 in both the first symbol and the second symbol of a subframe, and the second set of RS beam 210 may be used to transmit RS in both the third symbol and the fourth symbol of a subframe, for example, to increase the likelihood of successful decoding by UE 215 in poor conditions.

[0099] Figure 3 An example of a process 300 for supporting determination of beam candidates for transmitting a BFR signal is shown according to various aspects of the present disclosure. In some examples, the process 300 may implement aspects of the wireless communication system 100 / 200. The process 300 may include a base station 305 and a UE 310, which may be examples of corresponding devices described herein.

[0100] At 315, the base station 305 may transmit (and the UE 310 may receive) an RS beam. The RS beam may include an SS beam, a PBCH block, a CSI-RS, and the like.

[0101] At 320, UE 310 may identify a beam failure condition. A beam failure condition may be triggered or otherwise identified based on satisfying defined criteria. As a non-limiting example, this may include an estimated BLER of a control channel falling below a threshold.

[0102] At 325, the UE 310 may determine whether any RS beam satisfies a beam strength threshold. In some aspects, this may include detecting a set of RS beams and determining that more than one of the RS beams in the set satisfies the beam strength threshold. The UE 310 may select any of the more than one RS beams as a reference signal beam. The UE 310 may select an RS beam with the highest beam strength from the more than one RS beams as the RS beam.

[0103] In some aspects, this may include: the UE 310 detecting a set of RS beams and determining that an RS beam in the set fails to meet a beam strength threshold. The UE 310 may select any RS beam from the detected set of RS beams as a reference signal beam. The UE 310 may select an RS beam with the highest beam strength from the set of RS beams as the RS beam.

[0104] In some aspects, UE 310 may receive a configuration message (eg, from base station 305) indicating a beam strength threshold.

[0105] At 330, the UE 310 may use resources associated with an RS beam (eg, an RS beam that satisfies a threshold) to transmit a BFR signal (and the base station 305 may use the resources to receive the BFR signal).

[0106] Figure 4 A block diagram 400 of a wireless device 405 that supports determining beam candidates for transmitting a BFR signal is shown according to aspects of the present disclosure. The wireless device 405 may be an example of aspects of the UE 115 as described herein. The wireless device 405 may include a receiver 410, a communication manager 415, and a transmitter 420. The wireless device 405 may also include a processor. Each of these components may communicate with each other (e.g., via one or more buses).

[0107] The receiver 410 may receive information such as packets, user data, or control information associated with various information channels (e.g., control channels, data channels, and information related to determining beam candidates for transmitting BFR signals, etc.). The information may be communicated to other components of the device. The receiver 410 may be a reference Figure 7 Examples of various aspects of the transceiver 735 are described. The receiver 410 may utilize a single antenna or a group of antennas.

[0108] The communication manager 415 may be a reference Figure 7 Examples of various aspects of communications manager 715 are described.

[0109] At least some of the communication manager 415 and / or its various subcomponents may be implemented in hardware, software executed by a processor, firmware, or any combination thereof. If implemented in software executed by a processor, the functions of at least some of the communication manager 415 and / or its various subcomponents may be performed by a general purpose processor, digital signal processor (DSP), application specific integrated circuit (ASIC), field programmable gate array (FPGA) or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described in the present disclosure. At least some of the communication manager 415 and / or its various subcomponents may be physically located at various locations, including being distributed so that part of the functions are implemented at different physical locations by one or more physical devices. In some examples, according to various aspects of the present disclosure, at least some of the communication manager 415 and / or its various subcomponents may be separate and different components. In other examples, in accordance with various aspects of the present disclosure, the communications manager 415 and / or at least some of its various subcomponents may be combined with one or more other hardware components (including, but not limited to, I / O components, a transceiver, a network server, another computing device, one or more other components described in the present disclosure, or a combination thereof).

[0110] The communication manager 415 may perform the following operations: identifying a beam failure condition; determining whether a reference signal beam satisfies a beam strength threshold; and based on a result of the determination, transmitting a BFR signal using resources associated with the reference signal beam.

[0111] Transmitter 420 may transmit signals generated by other components of the device. In some examples, transmitter 420 may be co-located with receiver 410 in a transceiver module. For example, transmitter 420 may be a reference Figure 7 Examples of various aspects of the transceiver 735 are described. The transmitter 420 may utilize a single antenna or a group of antennas.

[0112] Figure 5 A block diagram 500 of a wireless device 505 that supports determining beam candidates for transmitting a BFR signal is shown according to aspects of the present disclosure. The wireless device 505 may be as described in reference Figure 4Examples of various aspects of the wireless device 405 or UE 115 are described. The wireless device 505 may include a receiver 510, a communication manager 515, and a transmitter 520. The wireless device 505 may also include a processor. Each of these components may communicate with each other (e.g., via one or more buses).

[0113] The receiver 510 may receive information such as packets, user data, or control information associated with various information channels (e.g., control channels, data channels, and information related to determining beam candidates for transmitting BFR signals, etc.). The information may be communicated to other components of the device. The receiver 510 may be a reference Figure 7 Examples of various aspects of the transceiver 735 are described. The receiver 510 may utilize a single antenna or a group of antennas.

[0114] The communication manager 515 may be a reference Figure 7 5. The communication manager 515 may also include a beam failure condition manager 525, an RS beam candidate manager 530, and a BFR signal manager 535. The beam failure condition manager 525 may identify a beam failure condition.

[0115] The RS beam candidate manager 530 may determine whether the reference signal beam satisfies a beam strength threshold. In some cases, determining whether the reference signal beam satisfies the beam strength threshold includes determining that the reference signal beam is received with a beam strength metric that satisfies the threshold. In some cases, the beam strength metric includes one or more of: an RSRP metric, or an RSRQ metric, or a SINR, or an estimated BLER, or a combination thereof.

[0116] The BFR signal manager 535 may transmit the BFR signal using resources associated with the reference signal beam based on the result of the determination.

[0117] Transmitter 520 may transmit signals generated by other components of the device. In some examples, transmitter 520 may be co-located with receiver 510 in a transceiver module. For example, transmitter 520 may be a reference Figure 7 Examples of various aspects of the transceiver 735 are described. The transmitter 520 may utilize a single antenna or a group of antennas.

[0118] Figure 6 A block diagram 600 of a communication manager 615 that supports determining beam candidates for transmitting BFR signals is shown in accordance with aspects of the present disclosure. The communication manager 615 may be a reference Figure 4 , 57 and 8. The communication manager 615 may include a beam failure condition manager 620, an RS beam candidate manager 625, a BFR signal manager 630, an RS beam set manager 635, and a configuration manager 640. Each of these modules may communicate with each other directly or indirectly (e.g., via one or more buses).

[0119] The beam failure condition manager 620 may identify a beam failure condition.

[0120] The RS beam candidate manager 625 may determine whether the reference signal beam satisfies a beam strength threshold. In some cases, determining whether the reference signal beam satisfies the beam strength threshold includes determining that the reference signal beam is received with a beam strength metric that satisfies the threshold. In some cases, the beam strength metric includes one or more of the following: an RSRP metric, or an RSRQ metric, or an SINR, or an estimated BLER, or a combination thereof.

[0121] The BFR signal manager 630 may transmit the BFR signal using resources associated with the reference signal beam based on the result of the determination.

[0122] The RS beam set manager 635 can perform the following operations: detect a set of reference signal beams, and determine that a reference signal beam in the set fails to meet a beam strength threshold; detect a set of reference signal beams, and determine that a reference signal beam in the set fails to meet a beam strength threshold; select any reference signal beam from the detected set of reference signal beams as a reference signal beam; select a reference signal beam with the highest beam strength from the set of reference signal beams as a reference signal beam; detect a set of reference signal beams, and determine that more than one reference signal beam in the set meets the beam strength threshold; select any reference signal beam from more than one reference signal beams as a reference signal beam; and select a reference signal beam with the highest beam strength from more than one reference signal beams as a reference signal beam.

[0123] Configuration manager 640 may receive a configuration message indicating a beam strength threshold.

[0124] Figure 7 A diagram of a system 700 including a device 705 that supports determining beam candidates for transmitting a BFR signal is shown according to aspects of the present disclosure. The device 705 may be an example of or a component that includes: Figure 4 and 5) described in the wireless device 405, wireless device 505, or UE 115. Device 705 may include components for two-way voice and data communications, including components for sending and receiving communications, including: communication manager 715, processor 720, memory 725, software 730, transceiver 735, antenna 740, and I / O controller 745. These components can communicate electronically via one or more buses (e.g., bus 710). Device 705 can communicate wirelessly with one or more base stations 105.

[0125] The processor 720 may include an intelligent hardware device (e.g., a general purpose processor, a DSP, a central processing unit (CPU), a microcontroller, an ASIC, an FPGA, a programmable logic device, a discrete gate or transistor logic component, a discrete hardware component, or any combination thereof). In some cases, the processor 720 may be configured to operate a memory array using a memory controller. In other cases, the memory controller may be integrated into the processor 720. The processor 720 may be configured to execute computer-readable instructions stored in the memory to perform various functions (e.g., functions or tasks that support determining beam candidates for transmitting BFR signals).

[0126] The memory 725 may include random access memory (RAM) and read-only memory (ROM). The memory 725 may store computer-readable, computer-executable software 730 including instructions that, when executed, cause the processor to perform the various functions described herein. In some cases, the memory 725 may also include a basic input / output (I / O) system (BIOS), etc., which may control basic hardware or software operations (such as interaction with peripheral components or devices).

[0127] The software 730 may include code for implementing various aspects of the present disclosure, including code for supporting determination of beam candidates for transmitting BFR signals. The software 730 may be stored in a non-transitory computer-readable medium such as a system memory or other memory. In some cases, the software 730 may not be directly executable by a processor, but may cause a computer (e.g., when compiled and executed) to perform the functions described herein.

[0128] The transceiver 735 may communicate bidirectionally via one or more antennas, wired or wireless links as described herein. For example, the transceiver 735 may represent a wireless transceiver and may communicate bidirectionally with another wireless transceiver. The transceiver 735 may also include a modem for modulating packets and providing the modulated packets to an antenna for transmission, and demodulating packets received from an antenna.

[0129] In some cases, a wireless device may include a single antenna 740. However, in some cases, a device may have more than one antenna 740, which may be capable of sending or receiving multiple wireless transmissions concurrently.

[0130] I / O controller 745 can manage input and output signals for device 705. I / O controller 745 can also manage peripheral devices that are not integrated into device 705. In some cases, I / O controller 745 can represent a physical connection or port to an external peripheral device. In some cases, I / O controller 745 can utilize a computer such as a MS- 705. In some cases, the I / O controller 745 may be implemented as part of a processor. In some cases, a user may interact with the device 705 via the I / O controller 745 or via the hardware components controlled by the I / O controller 745.

[0131] Figure 8 According to various aspects of the present disclosure, a flow chart illustrating a method 800 for determining beam candidates for transmitting a BFR signal is shown. The operations of the method 800 may be implemented by a UE 115 or a component thereof as described herein. For example, the operations of the method 800 may be implemented by a UE 115 or a component thereof as described herein. Figures 4 to 7 In some examples, the UE 115 may execute a code set to control the functional elements of the device to perform the functions described herein. Additionally or alternatively, the UE 115 may use dedicated hardware to perform various aspects of the functions described herein.

[0132] At 805, UE 115 may identify a beam failure condition. The operations of 805 may be performed according to the methods described herein. In some examples, aspects of the operations of 805 may be performed as described in reference to Figures 4 to 7 The beam fault condition manager described is executed.

[0133] At 810, UE 115 may determine whether the reference signal beam satisfies a beam strength threshold. The operations of 810 may be performed according to the methods described herein. In some examples, aspects of the operations of 810 may be performed as described in reference to Figures 4 to 7 The RS beam candidate manager described is executed.

[0134] At 815, UE 115 may transmit a BFR signal using resources associated with the reference signal beam based at least in part on the result of the determination. In some examples, hardware (such as an antenna) may be configured to transmit a BFR signal using resources associated with the reference signal beam based at least in part on the result of the determination. The operations of 815 may be performed according to the methods described herein. In some examples, aspects of the operations of 815 may be performed by, for example, Figures 4 to 7 Describes the BFR signal manager to perform.

[0135] Fig. 9 According to various aspects of the present disclosure, a flow chart illustrating a method 900 for determining beam candidates for transmitting a BFR signal is shown. The operations of the method 900 may be implemented by a UE 115 or a component thereof as described herein. For example, the operations of the method 900 may be implemented by a UE 115 or a component thereof as described herein. Figures 4 to 7 In some examples, the UE 115 may execute a code set to control the functional elements of the device to perform the functions described herein. Additionally or alternatively, the UE 115 may use dedicated hardware to perform various aspects of the functions described herein.

[0136] At 905, UE 115 may identify a beam failure condition. The operations of 905 may be performed according to the methods described herein. In some examples, aspects of the operations of 905 may be performed as described in reference to Figures 4 to 7 The beam fault condition manager described is executed.

[0137] At 910, UE 115 may determine whether the reference signal beam satisfies a beam strength threshold. The operations of 910 may be performed according to the methods described herein. In some examples, aspects of the operations of 910 may be performed as described in reference to Figures 4 to 7 The RS beam candidate manager described is executed.

[0138] At 915, UE 115 may detect a set of reference signal beams and determine that a reference signal beam in the set fails to meet a beam strength threshold. The operations of 915 may be performed according to the methods described herein. In some examples, aspects of the operations of 915 may be performed as described in reference to Figures 4 to 7 The RS beam set manager described is used to perform.

[0139] At 920, UE 115 may select any reference signal beam from the set of detected reference signal beams as the reference signal beam. The operations of 920 may be performed according to the methods described herein. In some examples, aspects of the operations of 920 may be performed as described in reference to Figures 4 to 7 The RS beam set manager described is used to perform.

[0140] At 925, UE 115 may transmit a BFR signal using resources associated with the reference signal beam based at least in part on the result of the determination. In some examples, hardware (such as an antenna) may be configured to transmit a BFR signal using resources associated with the reference signal beam based at least in part on the result of the determination. The operations of 925 may be performed according to the methods described herein. In some examples, aspects of the operations of 925 may be performed as described in reference to Figures 4 to 7 Describes the BFR signal manager to perform.

[0141] Fig.10 According to various aspects of the present disclosure, a flow chart illustrating a method 1000 for determining beam candidates for transmitting a BFR signal is shown. The operations of the method 1000 may be implemented by a UE 115 or a component thereof as described herein. For example, the operations of the method 1000 may be implemented by a UE 115 or a component thereof as described herein. Figures 4 to 7 In some examples, the UE 115 may execute a code set to control the functional elements of the device to perform the functions described herein. Additionally or alternatively, the UE 115 may use dedicated hardware to perform various aspects of the functions described herein.

[0142] At 1005, UE 115 may identify a beam failure condition. The operations of 1005 may be performed according to the methods described herein. In some examples, aspects of the operations of 1005 may be performed as described in reference to Figures 4 to 7 The beam fault condition manager described is executed.

[0143] At 1010, UE 115 may determine whether the reference signal beam satisfies a beam strength threshold. The operations of 1010 may be performed according to the methods described herein. In some examples, aspects of the operations of 1010 may be performed as described in reference to Figures 4 to 7 The RS beam candidate manager described is executed.

[0144] At 1015, UE 115 may detect a set of reference signal beams and determine that a reference signal beam in the set fails to meet a beam strength threshold. The operations of 1015 may be performed according to the methods described herein. In some examples, aspects of the operations of 1015 may be performed as described in reference to Figures 4 to 7 The RS beam set manager described is used to perform.

[0145] At 1020, UE 115 may select a reference signal beam having the highest beam strength from the set of reference signal beams as the reference signal beam. The operations of 1020 may be performed according to the methods described herein. In some examples, aspects of the operations of 1020 may be performed as described in reference to Figures 4 to 7 The RS beam set manager described is used to perform.

[0146] At 1025, UE 115 may transmit a BFR signal using resources associated with the reference signal beam based at least in part on the result of the determination. In some examples, hardware (such as an antenna) may be configured to transmit a BFR signal using resources associated with the reference signal beam based at least in part on the result of the determination. The operations of 1025 may be performed according to the methods described herein. In some examples, aspects of the operations of 1025 may be performed as described in reference to Figures 4 to 7 Describes the BFR signal manager to perform.

[0147] It should be noted that the methods described herein describe possible implementations, and that operations and steps may be rearranged or otherwise modified, and that other implementations are possible. Furthermore, aspects from two or more methods may be combined.

[0148] The technology described herein can be used in various wireless communication systems, such as code division multiple access (CDMA), time division multiple access (TDMA), frequency division multiple access (FDMA), orthogonal frequency division multiple access (OFDMA), single carrier frequency division multiple access (SC-FDMA) and other systems. CDMA systems can implement radio technologies such as CDMA2000, Universal Terrestrial Radio Access (UTRA), etc. CDMA2000 covers IS-2000, IS-95 and IS-856 standards. IS-2000 versions can be generally referred to as CDMA2000 1X, 1X, etc. IS-856 (TIA-856) is generally referred to as CDMA2000 1xEV-DO, High Speed ​​Packet Data (HRPD), etc. UTRA includes broadband CDMA (W-CDMA) and other variants of CDMA. TDMA systems can implement radio technologies such as Global System for Mobile Communications (GSM).

[0149] OFDMA systems can implement radio technologies such as Ultra Mobile Broadband (UMB), Evolved UTRA (E-UTRA), Institute of Electrical and Electronics Engineers (IEEE) 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802.20, Flash-OFDM, etc. UTRA and E-UTRA are parts of Universal Mobile Telecommunications System (UMTS). LTE, LTE-A, and LTE-A Pro are versions of UMTS that use E-UTRA. UTRA, E-UTRA, UMTS, LTE, LTE-A, LTE-A Pro, NR, and GSM are described in documents from an organization named "3rd Generation Partnership Project" (3GPP). CDMA2000 and UMB are described in documents from an organization named "3rd Generation Partnership Project 2" (3GPP2). The technology described herein can be used for the systems and radio technologies mentioned above as well as other systems and radio technologies. Although aspects of LTE, LTE-A, LTE-A Pro, or NR systems may be described for example purposes, and LTE, LTE-A, LTE-A Pro, or NR terminology may be used in much of the description, the techniques described herein may be applicable beyond LTE, LTE-A, LTE-A Pro, or NR applications.

[0150] A macro cell typically covers a relatively large geographic area (e.g., a radius of several kilometers) and may allow unrestricted access by a UE 115 with a service subscription to a network provider. Small cells may be associated with lower power base stations 105 than macro cells, and small cells may operate in the same or different frequency bands (e.g., licensed, unlicensed, etc.) as macro cells. According to various examples, small cells may include pico cells, femto cells, and micro cells. For example, a pico cell may cover a small geographic area and may allow unrestricted access by a UE 115 with a service subscription to a network provider. A femto cell may also cover a small geographic area (e.g., a residence) and may provide restricted access by a UE 115 associated with the femto cell (e.g., a UE 115 in a closed subscriber group (CSG), a UE 115 for a user in a residence, etc.). An eNB for a macro cell may be referred to as a macro eNB. An eNB for a small cell may be referred to as a small cell eNB, a pico eNB, a femto eNB, or a home eNB. An eNB may support one or more (eg, two, three, four, etc.) cells and may also support communications using one or more component carriers.

[0151] The wireless communication system 100 or systems described herein may support synchronous operation or asynchronous operation. For synchronous operation, the base stations 105 may have similar frame timing, and transmissions from different base stations 105 may be approximately aligned in time. For asynchronous operation, the base stations 105 may have different frame timing, and transmissions from different base stations 105 may not be aligned in time. The techniques described herein may be used for synchronous operation or asynchronous operation.

[0152] The information and signals described herein may be represented using any of a variety of different techniques and methods. For example, the data, instructions, commands, information, signals, bits, symbols, and chips mentioned throughout the above description may be represented by voltage, current, electromagnetic waves, magnetic fields or particles, optical fields or particles, or any combination thereof.

[0153] The various illustrative blocks and modules described in conjunction with the disclosure herein may be implemented or executed using a general purpose processor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA) or other programmable logic device (PLD), discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. A general purpose processor may be a microprocessor, but in an alternative, the processor may be any conventional processor, controller, microcontroller, or state machine. The processor may also be implemented as a combination of computing devices (e.g., a combination of a DSP and a microprocessor, a plurality of microprocessors, a combination of one or more microprocessors and a DSP core, or any other such configuration).

[0154] The functions described herein may be implemented in hardware, software executed by a processor, firmware, or any combination thereof. If implemented in software executed by a processor, the functions may be stored on or sent through a computer-readable medium as one or more instructions or codes. Other examples and implementations are within the scope of the present disclosure and the appended claims. For example, due to the nature of software, the functions described herein may be implemented using software executed by a processor, hardware, firmware, hard wiring, or a combination of any of these items. Features that implement the functions may also be physically located at various locations, including being distributed so that portions of the functions are implemented at different physical locations.

[0155] Computer readable medium includes both non-transitory computer storage medium and communication medium, and communication medium includes any medium that promotes computer program to be transmitted from one place to another place.Non-transitory storage medium can be any available medium that can be accessed by general-purpose computer or special-purpose computer.By way of example and not limitation, non-transitory computer readable medium can include random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory, compact disc (CD) ROM or other optical disc storage, disk storage or other magnetic storage device, or can be used for carrying or storing desired program code unit and can be accessed by general-purpose or special-purpose computer or general-purpose or special-purpose processor in the form of instruction or data structure.In addition, any connection is appropriately referred to as computer readable medium.For example, if software is to be sent from website, server or other remote source using coaxial cable, optical fiber cable, twisted pair, digital subscriber line (DSL) or wireless technology such as infrared, radio and microwave, then coaxial cable, optical fiber cable, twisted pair, DSL or wireless technology such as infrared, radio and microwave are included in the definition of medium. As used herein, disk and disc include CD, laser disc, optical disc, digital versatile disc (DVD), floppy disk and Blu-ray disc, wherein disks usually reproduce data magnetically, while discs reproduce data optically with lasers. Combinations of the above are also included within the scope of computer-readable media.

[0156] As used herein (including in the claims), "or" as used in a list of items (e.g., a list of items ending with a phrase such as "at least one of" or "one or more of") indicates an inclusive list, so that, for example, a list of at least one of A, B, or C means A or B or C or AB or AC or BC or ABC (e.g., A and B and C). In addition, as used herein, the phrase "based on" should not be interpreted as a reference to a closed set of conditions. For example, an exemplary step described as "based on condition A" can be based on both condition A and condition B without departing from the scope of the present disclosure. In other words, as used herein, the phrase "based on" should be interpreted in the same manner as the phrase "based at least in part on."

[0157] In the accompanying drawings, similar components or features may have the same reference number. In addition, various components of the same type may be distinguished by following the reference number with a dash and a second reference number, the second reference number being used to distinguish between similar components. If only the first reference number is used in the specification, the description applies to any of the similar components having the same first reference number, without regard to the second reference number or other subsequent reference numbers.

[0158] The descriptions set forth herein in conjunction with the accompanying drawings describe example configurations, and do not represent all examples that may be implemented or within the scope of the claims. The term "exemplary" as used herein means "used as an example, instance, or illustration," rather than "preferred" or "advantageous over other examples." For the purpose of providing an understanding of the described techniques, the detailed description includes specific details. However, these techniques may be practiced without these specific details. In some instances, well-known structures and devices are shown in block diagram form to avoid obscuring the concepts of the described examples.

[0159] The description herein is provided to enable those skilled in the art to make or use the present disclosure. It will be apparent to those skilled in the art that various modifications to the present disclosure will be apparent, and the general principles defined herein may be applied to other variations without departing from the scope of the present disclosure. Therefore, the present disclosure is not limited to the examples and designs described herein, but is intended to conform to the broadest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for wireless communication, comprising: receiving a configuration message indicating a beam strength threshold; detecting a set of reference signal beams and determining, before any beam failure condition is identified, that more than one of the reference signal beams in the set are received with respective beam strength metrics greater than the beam strength threshold; identifying that a beam failure condition has occurred; selecting a reference signal beam from the more than one reference signal beams, wherein if each beam direction is associated with a defined time slot, selecting a beam direction that reduces a time before a beam failure recovery (BFR) signal is transmitted; and The BFR signal is transmitted using resources associated with the selected reference signal beam, wherein the beam strength threshold is used to determine the reference signal beam associated with the resources used to transmit the BFR signal.

2. The method according to claim 1, wherein: The beam strength metric includes one or more of: a reference signal received power (RSRP) metric, or a reference signal received quality (RSRQ) metric, a signal to interference plus noise ratio (SINR), an estimated block error rate (BLER), or a combination thereof.

3. The method according to claim 1, wherein: Selecting the reference signal beam includes: The reference signal beam is selected from the more than one reference signal beams based at least in part on the reference signal beam having a highest beam strength among the more than one reference signal beams.

4. An apparatus for wireless communication, comprising: processor; a memory in electronic communication with the processor; as well as Instructions, which are stored in the memory and can be executed by the processor to cause the device to perform the following operations: receiving a configuration message indicating a beam strength threshold; detecting a set of reference signal beams and determining, before any beam failure condition is identified, that more than one of the reference signal beams in the set are received with respective beam strength metrics greater than the beam strength threshold; identifying that a beam failure condition has occurred; as well as selecting a reference signal beam from the more than one reference signal beams, wherein if each beam direction is associated with a defined time slot, selecting a beam direction that reduces a time before a beam failure recovery (BFR) signal is transmitted; and An antenna is configured to transmit the BFR signal using resources associated with the selected reference signal beam, wherein the beam strength threshold is used to determine the reference signal beam associated with the resources for transmitting the BFR signal.

5. The device according to claim 4, wherein: The beam strength metric includes one or more of: a reference signal received power (RSRP) metric, or a reference signal received quality (RSRQ) metric, a signal to interference plus noise ratio (SINR), an estimated block error rate (BLER), or a combination thereof.

6. The device according to claim 4, wherein: The instructions for selecting the reference signal beam may be executed by the processor to cause the apparatus to perform the following operations: The reference signal beam is selected from the more than one reference signal beams based at least in part on the reference signal beam having a highest beam strength among the more than one reference signal beams.

7. An apparatus for wireless communication, comprising: means for receiving a configuration message indicating a beam strength threshold; means for detecting a set of reference signal beams and determining that more than one of the reference signal beams in the set are received with respective beam strength metrics greater than the beam strength threshold before any beam failure condition is identified; means for identifying that a beam failure condition has occurred; means for selecting a reference signal beam from the more than one reference signal beams, wherein if each beam direction is associated with a defined time slot, a beam direction is selected that reduces a time before a beam failure recovery (BFR) signal is transmitted; and Means for transmitting the BFR signal using resources associated with the selected reference signal beam, wherein the beam strength threshold is used to determine the reference signal beam associated with the resources used to transmit the BFR signal.

8. The device according to claim 7, wherein: The beam strength metric includes one or more of: a reference signal received power (RSRP) metric, or a reference signal received quality (RSRQ) metric, a signal to interference plus noise ratio (SINR), an estimated block error rate (BLER), or a combination thereof.

9. The device according to claim 7, wherein: Selecting the reference signal beam includes: Means for selecting the reference signal beam from among the more than one reference signal beams based at least in part on the reference signal beam having a highest beam strength among the more than one reference signal beams.

10. A non-transitory computer-readable medium storing code for wireless communication, the code comprising instructions executable by a processor to: receiving a configuration message indicating a beam strength threshold; detecting a set of reference signal beams and determining, before any beam failure condition is identified, that more than one of the reference signal beams in the set are received with respective beam strength metrics greater than the beam strength threshold; identifying that a beam failure condition has occurred; selecting a reference signal beam from the more than one reference signal beams, wherein if each beam direction is associated with a defined time slot, selecting a beam direction that reduces a time before a beam failure recovery (BFR) signal is transmitted; and The BFR signal is transmitted using resources associated with the selected reference signal beam, wherein the beam strength threshold is used to determine the reference signal beam associated with the resources used to transmit the BFR signal.

11. The non-transitory computer readable medium of claim 10, wherein: The beam strength metric includes one or more of: a reference signal received power (RSRP) metric, or a reference signal received quality (RSRQ) metric, a signal to interference plus noise ratio (SINR), an estimated block error rate (BLER), or a combination thereof.

12. The non-transitory computer readable medium of claim 10, wherein: The instructions for selecting the reference signal beam may be executed by the processor to perform the following operations: The reference signal beam is selected from the more than one reference signal beams based at least in part on the reference signal beam having a highest beam strength among the more than one reference signal beams.

Images