Beam sweeping

Abstract

A user equipment (UE) of a wireless communication network receives conditions for sweeping a beam between a base station of the network and the UE. These conditions include beam sweeping triggering rules and a beam measurement configuration for measuring at least one characteristic of each beam on the downlink. The UE measures the at least one characteristic of each beam according to the measurement configuration. After the measurements, the UE detects a trigger according to the triggering rules. In response to detecting the trigger, the UE sweeps the beam on the uplink based on the measurements.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application is an international phase application claiming priority to Greek patent application No. 20200100178, filed on April 7, 2020, entitled “BEAM SWEEPING”, the disclosure of which is hereby incorporated herein in its entirety. background Technical Field

[0004] The present disclosure relates generally to communication systems and, in some examples, more particularly to controlling beam sweeping of cross-channel beams between user equipment (UE) of a wireless communication network and a base station of the network.

[0005] introduction

[0006] Wireless communication systems are widely deployed to provide various telecommunication services such as telephone, video, data, messaging, and broadcasting. Typical wireless communication systems may employ multiple access technologies that can support communication with multiple users by sharing available system resources. Examples of such multiple access technologies include code division multiple access (CDMA) systems, time division multiple access (TDMA) systems, frequency division multiple access (FDMA) systems, orthogonal frequency division multiple access (OFDMA) systems, single carrier frequency division multiple access (SC-FDMA) systems, and time division synchronous code division multiple access (TD-SCDMA) systems. These multiple access technologies have been adopted in various telecommunication standards to provide a common protocol that enables different wireless devices to communicate at a city, country, region, and even global level. An example telecommunication standard is 5G New Radio (NR). 5G NR is part of the continued mobile broadband evolution promulgated by the Third Generation Partnership Project (3GPP) to meet new requirements associated with latency, reliability, security, scalability (e.g., with the Internet of Things (IoT)) and other requirements. 5G NR includes services associated with enhanced mobile broadband (eMBB), massive machine-type communications (mMTC), and ultra-reliable low-latency communications (URLLC). Some aspects of 5G NR may be based on the 4G Long Term Evolution (LTE) standard. There is a need for further improvements to 5G NR technology. These improvements may also be applicable to other multiple access technologies and the telecommunications standards that employ them.

[0007] Overview

[0008] The following is a brief summary of one or more aspects to provide a basic understanding of such aspects. This summary is not an exhaustive overview of all conceivable aspects and is neither intended to identify key or critical elements of all aspects nor to define the scope of any or all aspects. Its sole purpose is to present some concepts of one or more aspects in a simplified form as a prelude to the more detailed description that is presented later.

[0009] The technology disclosed herein includes methods, apparatus, and computer-readable media containing instructions for wireless communication. In this technology, a UE receives conditions for sweeping a beam between a base station of a network and the UE. These conditions include beam sweep triggering rules and a beam measurement configuration for measuring at least one characteristic of each beam on the downlink. The UE measures the at least one characteristic of each beam according to the measurement configuration. After the measurements, the UE detects a trigger according to the triggering rules. In response to detecting the trigger, the UE sweeps the beam on the uplink based on the measurements.

[0010] In some examples, a base station first transmits to a UE conditions for sweeping a beam between the UE and the base station. These conditions include a beam sweep trigger rule and a beam measurement configuration for measuring at least one characteristic of each beam on a downlink. The base station transmits a reference signal on a beam on a downlink for a second time by the base station after the first transmission. The base station receives downlink beam measurements according to the beam measurement configuration from the UE in response to the first transmission and the second transmission. In response to the reception, the base station prepares at least one beam that is currently not used in the downlink. The base station also receives an indication on at least one prepared beam swept by the UE that a trigger has been detected at the UE in accordance with the trigger rule. The base station then transmits at least one physical channel to the UE on at least one prepared beam.

[0011] In some examples, a base station transmits a beam sweep configuration specifying a reference signal to a UE of the network. The base station measures at least one characteristic of each of a plurality of beams of a physical channel from the UE to the base station on an uplink, each beam including the specified reference signal. The measured beams include each beam currently used for communication between the base station and the UE and a plurality of beams not currently used for downlink data transfer to the UE. After the measurement, the base station detects a beam sweep trigger condition. In response to the detection, the base station sweeps the plurality of measured beams on a downlink to the UE based on the measurement and the configuration.

[0012] In some examples, a UE receives a beam sweep configuration specifying a reference signal from a base station. The UE transmits the specified reference signal to the base station on each of a plurality of beams in a physical channel. The beams include each beam currently used for data transfer between the base station and the UE and a plurality of beams not currently used for data transfer from the base station to the UE. The UE receives the plurality of transmitted beams swept on a downlink to the UE for downlink data transfer from the base station to the UE based on the measurements and the configuration.

[0013] To accomplish the foregoing and related ends, one or more aspects comprise the features hereinafter fully described and particularly pointed out in the claims. The following description and accompanying drawings set forth in detail certain illustrative features of the one or more aspects. However, these features are indicative of but a few of the various ways in which the principles of the various aspects may be employed, and this description is intended to encompass all such aspects and their equivalents. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 is a diagram illustrating an example of a wireless communication system and an access network.

[0016] Figure 2A 、 2B , 2C, and 2D are diagrams illustrating examples of a first 5G / NR frame, a DL channel within a 5G / NR subframe, a second 5G / NR frame, and a UL channel within a 5G / NR subframe, respectively.

[0017] Figure 3 is a diagram illustrating a base station and a user equipment (UE) in an access network according to an example of the techniques disclosed herein.

[0018] Figure 4 is a diagram illustrating a relationship between a UE and a base station for wireless communication according to an example of the technology disclosed herein.

[0019] Figure 5 is a message flow diagram of an example method of wireless communication according to the technology disclosed herein.

[0020] Figure 6 is a flow chart of an example method of wireless communication according to the technology disclosed herein.

[0021] Figure 7 is a flow chart of an example method of wireless communication according to the technology disclosed herein.

[0022] Figure 8 is a flow chart of an example method of wireless communication according to the technology disclosed herein.

[0023] Figure 9 is a block diagram of an example UE according to the techniques disclosed herein.

[0024] Figure 10 is a flow chart of an example method of wireless communication according to the technology disclosed herein.

[0025] Figure 11 is a flow chart of an example method of wireless communication according to the technology disclosed herein.

[0026] Figure 12 is a flow chart of an example method of wireless communication according to the technology disclosed herein.

[0027] Figure 13 is a block diagram of an example base station according to the techniques disclosed herein.

[0028] Figure 14 is a diagram illustrating a relationship between a UE and a base station for wireless communication according to an example of the technology disclosed herein.

[0029] Figure 15 is a flow chart of an example method of wireless communication according to the technology disclosed herein.

[0030] Figure 16 is a flow chart of an example method of wireless communication according to the technology disclosed herein.

[0031] Figure 17 is a flow chart of an example method of wireless communication according to the technology disclosed herein.

[0032] Figure 18 is a flow chart of an example method of wireless communication according to the technology disclosed herein.

[0033] Figure 19 is a block diagram of an example base station according to the techniques disclosed herein.

[0034] Figure 20 is a flow chart of an example method of wireless communication according to the technology disclosed herein.

[0035] Figure 21 is a flow chart of an example method of wireless communication according to the technology disclosed herein.

[0036] Figure 22 is a flow chart of an example method of wireless communication according to the technology disclosed herein.

[0037] Figure 23 is a flow chart of an example method of wireless communication according to the technology disclosed herein.

[0038] Figure 24 is a flow chart of an example method of wireless communication according to the technology disclosed herein.

[0039] Figure 25 is a block diagram of an example UE according to the techniques disclosed herein.

[0040] Detailed description

[0041] The detailed description set forth below in conjunction with the accompanying drawings is intended as a description of various configurations and is not intended to represent the only configurations in which the concepts described herein may be practiced. This detailed description includes specific details to provide a thorough understanding of the various concepts. However, it will be apparent to those skilled in the art that these concepts may be practiced without these specific details. In some instances, well-known structures and components are shown in block diagram form to avoid obscuring such concepts.

[0042] In some frequency ranges, such as the "millimeter wave" (mmW) range for 5G, radio waves are more susceptible to blockage and interference than the lower-frequency waves used in earlier wireless communication systems. This means that mmW can be easily interrupted / blocked by, for example, a person's hand or head using a UE. 5G NR use cases such as mMTC and URLLC can use beam diversity / redundancy in the physical channel between the base station and the UE to address the possibility of blockage while maintaining the quality of service expected for these use cases.

[0043] While this approach generally works, it's still less effective than expected in some cases. For example, if mmW downlink transmissions between a 5G base station and a 5G UE are blocked, the UE will eventually declare beam failure or radio link failure and issue a new random access request to the network. However, the random access process can take tens of one-millisecond cycles to complete, which is too long for 5G use cases such as mMTC and URLLC.

[0044] In various aspects of the present disclosure, methods, non-transitory computer-readable media, and apparatus are provided. In some examples of the techniques disclosed herein, a UE receives conditions for sweeping a beam between a base station of a network and the UE. The conditions include beam sweeping triggering rules and a beam measurement configuration for measuring at least one characteristic of each beam on a downlink. The UE measures the at least one characteristic of each beam according to the measurement configuration. After the measurements, the UE detects a trigger according to the triggering rules. In response to detecting the trigger, the UE sweeps the beam on an uplink based on the measurements.

[0045] In some aspects, a base station first transmits to a UE conditions for sweeping a beam between the UE and the base station. These conditions include a beam sweep trigger rule and a beam measurement configuration for measuring at least one characteristic of each beam on a downlink. After the first transmission, the base station transmits a reference signal on a beam on a downlink for a second time by the base station. In response to the first transmission and the second transmission, the base station receives downlink beam measurements according to the beam measurement configuration from the UE. In response to the reception, the base station prepares at least one beam that is currently not used in the downlink. The base station also receives an indication on at least one prepared beam swept by the UE that a trigger has been detected at the UE according to the trigger rule. The base station then transmits at least one physical channel to the UE on the at least one prepared beam.

[0046] In some aspects, a base station transmits a beam sweep configuration for a designated reference signal to a UE of a network. The base station measures at least one characteristic of each of a plurality of beams of a physical channel, each beam including the designated reference signal on an uplink from the UE to the base station. The beams measured by the beam sweep configuration include each beam currently used for communication between the base station and the UE and a plurality of beams not currently used for downlink data transfer to the UE. After the measurement, the base station detects a beam sweep trigger condition. In response to the detection, the base station sweeps the plurality of measured beams on a downlink to the UE based on the measurement and the configuration.

[0047] In some aspects, a UE receives a beam sweep configuration specifying a reference signal from a base station. The UE transmits the specified reference signal to the base station on each of a plurality of beams in a physical channel. The beams include each beam currently used for data transfer between the base station and the UE and a plurality of beams not currently used for data transfer from the base station to the UE. The UE receives the plurality of transmitted beams swept on a downlink to the UE for downlink data transfer from the base station to the UE based on the measurements and the configuration.

[0048] To accomplish the foregoing and related ends, one or more aspects comprise the features hereinafter fully described and particularly pointed out in the claims. The following description and accompanying drawings set forth in detail certain illustrative features of the one or more aspects. However, these features are indicative of but a few of the various ways in which the principles of the various aspects may be employed, and this description is intended to encompass all such aspects and their equivalents.

[0049] Several aspects of telecommunications systems will now be presented with reference to various apparatuses and methods. These apparatuses and methods will be described in the following detailed description and illustrated in the accompanying drawings by various blocks, components, circuits, processes, algorithms, etc. (collectively, "elements"). These elements may be implemented using electronic hardware, computer software, or any combination thereof. Whether such elements are implemented as hardware or software depends on the specific application and the design constraints imposed on the overall system. By way of example, an element, or any portion of an element, or any combination of elements may be implemented as a "processing system" comprising one or more processors. Examples of processors include: a microprocessor, a microcontroller, a graphics processing unit (GPU), a central processing unit (CPU), an application processor, a digital signal processor (DSP), a reduced instruction set computing (RISC) processor, a system on a chip (SoC), a baseband processor, a field programmable gate array (FPGA), a programmable logic device (PLD), a state machine, gating logic, discrete hardware circuits, and other suitable hardware configured to perform the various functionalities described throughout this disclosure. One or more processors in the processing system may execute software. Software shall be construed broadly to mean instructions, instruction sets, code, code segments, program code, programs, subroutines, software components, applications, software applications, software packages, routines, subroutines, objects, executables, threads of execution, procedures, functions, etc., whether referred to as software, firmware, middleware, microcode, hardware description language, or otherwise.

[0050] Accordingly, in one or more example embodiments, the functions described may be implemented in hardware, software, or any combination thereof. If implemented in software, each function may be stored or encoded as one or more instructions or codes on a computer-readable medium. Computer-readable media include computer storage media. Storage media may be any available medium that can be accessed by a computer. By way of example and not limitation, such computer-readable media may include random access memory (RAM), read-only memory (ROM), electrically erasable programmable ROM (EEPROM), optical disk storage, magnetic disk storage, other magnetic storage devices, a combination of the aforementioned types of computer-readable media, or any other medium that can be used to store instructions or data structures in the form of computer-executable code that can be accessed by a computer.

[0051] Figure 11 is a diagram illustrating an example of a wireless communication system and access network 100. The wireless communication system (also known as a wireless wide area network (WWAN)) includes a base station 102, a UE 104, an evolved packet core (EPC) 160, and another core network 190 (e.g., a 5G core (5GC)). The base station 102 may include a macro cell (a high-power cellular base station) and / or a small cell (a low-power cellular base station). A macro cell includes a base station. A small cell includes a femto cell, a pico cell, and a micro cell. A base station 102 configured for 4G LTE (collectively referred to as the Evolved Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access Network (E-UTRAN)) can interface with the EPC 160 via a first backhaul link 132 (e.g., an S1 interface). A base station 102 configured for 5G NR (collectively referred to as the Next Generation RAN (NG-RAN)) can interface with the core network 190 via a second backhaul link 186. Among other functions, the base station 102 may also perform one or more of the following functions: delivery of user data, radio channel encryption and decryption, integrity protection, header compression, mobility control functions (e.g., handover, dual connectivity), inter-cell interference coordination, connection establishment and release, load balancing, distribution of non-access stratum (NAS) messages, NAS node selection, synchronization, radio access network (RAN) sharing, multimedia broadcast multicast service (MBMS), subscriber and equipment tracking, RAN information management (RIM), paging, positioning, and delivery of alert messages. The base stations 102 may communicate with each other directly or indirectly (e.g., through the EPC 160 or the core network 190) over a third backhaul link 134 (e.g., an X2 interface). The first, second, and third backhaul links 132, 186, and 134 may be wired or wireless.

[0052] Base stations 102 can communicate wirelessly with UEs 104. Each base station 102 can provide communication coverage for a respective geographic coverage area 110. There may be overlapping geographic coverage areas 110. For example, a small cell 102′ can have a coverage area 110′ that overlaps with the coverage area 110 of one or more macro base stations 102. A network that includes both small cells and macro cells can be referred to as a heterogeneous network. A heterogeneous network can also include a home evolved Node B (eNB) (HeNB), which can provide service to a restricted group known as a closed subscriber group (CSG). The communication link 120 between the base station 102 and the UE 104 can include uplink (UL) (also known as reverse link) transmissions from the UE 104 to the base station 102 and / or downlink (DL) (also known as forward link) transmissions from the base station 102 to the UE 104. The communication link 120 can utilize multiple-input multiple-output (MIMO) antenna technology, including spatial multiplexing, beamforming, and / or transmit diversity. In some examples of the techniques disclosed herein, the same set of multiple beams is used for both DL and UL transmission / reception of physical channels between a base station and a UE. For example, a given set of beams may carry multiple copies of a physical downlink shared channel (PDSCH) on the DL, as described further below, and may carry multiple copies of a physical uplink control channel (PUCCH) on the UL, also as described further below.

[0053] These communication links may be over one or more carriers. For each carrier allocated in the carrier aggregation for a total of up to Yx MHz (x component carriers) for transmission in each direction, the base station 102 / UE 104 may use spectrum with a bandwidth of up to Y MHz (e.g., 5, 10, 15, 20, 100, 400 MHz, etc.). These carriers may or may not be adjacent to each other. The allocation of carriers may be asymmetric with respect to DL and UL (e.g., more or fewer carriers may be allocated to DL compared to UL). The component carriers may include a primary component carrier and one or more secondary component carriers. The primary component carrier may be referred to as a primary cell (PCell), and the secondary component carriers may be referred to as secondary cells (SCells).

[0054] Certain UEs 104 may communicate with each other using a device-to-device (D2D) communication link 158. The D2D communication link 158 may utilize the DL / UL WWAN spectrum. The D2D communication link 158 may utilize one or more sidelink channels, such as a physical sidelink broadcast channel (PSBCH), a physical sidelink discovery channel (PSDCH), a physical sidelink shared channel (PSSCH), and a physical sidelink control channel (PSCCH). D2D communication may be accomplished through various wireless D2D communication systems, such as, for example, FlashLinQ, WiMedia, Bluetooth, ZigBee, Wi-Fi based on the IEEE 802.11 standard, LTE, or NR. The wireless communication system may further include a Wi-Fi access point (AP) 150 in communication with a Wi-Fi station (STA) 152 via a communication link 154 in the 5 GHz unlicensed spectrum. When communicating in the unlicensed spectrum, the STA 152 / AP 150 may perform a clear channel assessment (CCA) to determine whether the channel is available before communicating. Small cell 102′ can operate in licensed and / or unlicensed spectrum. When operating in unlicensed spectrum, small cell 102′ can employ NR and use the same 5 GHz unlicensed spectrum used by Wi-Fi AP 150. Small cell 102′ employing NR in unlicensed spectrum can improve access network coverage and / or increase access network capacity.

[0055] Whether a small cell 102′ or a large cell (e.g., a macro base station), base station 102 may include and / or be referred to as an eNB, a gB node (gNB), or another type of base station. Some base stations, such as gNB 180, may operate in the traditional sub-6 GHz spectrum, millimeter wave (mmW) frequencies, and / or near-mmW frequencies to communicate with UE 104. When gNB 180 operates in mmW or near-mmW frequencies, gNB 180 may be referred to as a mmW base station. Extremely high frequency (EHF) is a portion of the RF spectrum in the electromagnetic spectrum. EHF has a range of 30 GHz to 300 GHz and a wavelength between 1 mm and 10 mm. Radio waves in this frequency band may be referred to as millimeter waves. Near-mmW may extend down to 3 GHz frequencies with a wavelength of 100 mm. The super high frequency (SHF) frequency band extends between 3 GHz and 30 GHz and is also referred to as centimeter waves. Communications using mmW / near-mmW radio frequency bands (e.g., 3 GHz–300 GHz) have extremely high path loss and short range—making mmW transmissions susceptible to blockage and attenuation, resulting in, for example, unsuccessful decoding of data. The mmW base station 180 can utilize beamforming 182 with the UE 104 / 184 to compensate for the extremely high path loss and short range. The base station 180 and the UE 104 can each include multiple antennas, such as antenna elements, antenna panels, and / or antenna arrays, to facilitate beamforming.

[0056] Base station 180 may transmit beamformed signals in one or more transmit directions 182′ to UE 104 / 184. UE 104 / 184 may receive beamformed signals from base station 180 in one or more receive directions 182″. UE 104 / 184 may also transmit beamformed signals in one or more transmit directions to base station 180. Base station 180 may receive beamformed signals in one or more receive directions from UE 104. Base station 180 / UE 104 / 184 may perform beam training to determine the best receive direction and transmit direction for each of base station 180 / UE 104 / 184. The transmit direction and receive direction of base station 180 may be the same or different. The transmit direction and receive direction of UE 104 / 184 may be the same or different.

[0057] EPC 160 may include a Mobility Management Entity (MME) 162, other MMEs 164, a Serving Gateway 166, a Multimedia Broadcast Multicast Service (MBMS) Gateway 168, a Broadcast Multicast Service Center (BM-SC) 170, and a Packet Data Network (PDN) Gateway 172. MME 162 may be in communication with a Home Subscriber Server (HSS) 174. MME 162 is a control node that handles signaling between UE 104 and EPC 160. Generally speaking, MME 162 provides bearer and connection management. All user Internet Protocol (IP) packets are passed through Serving Gateway 166, which itself is connected to PDN Gateway 172. PDN Gateway 172 provides UE IP address allocation and other functions. PDN Gateway 172 and BM-SC 170 are connected to IP Services 176. IP Services 176 may include the Internet, an intranet, an IP Multimedia Subsystem (IMS), PS streaming services, and / or other IP services. The BM-SC 170 can provide functionality for MBMS user service provisioning and delivery. The BM-SC 170 can serve as the entry point for content providers' MBMS transmissions, authorize and initiate MBMS bearer services within the Public Land Mobile Network (PLMN), and schedule MBMS transmissions. The MBMS Gateway 168 can be used to distribute MBMS traffic to base stations 102 within the Multicast Broadcast Single Frequency Network (MBSFN) area broadcasting a specific service, and can be responsible for session management (start / stop) and collecting eMBMS-related charging information.

[0058] The core network 190 may include an access and mobility management function (AMF) 192, other AMFs 193, a session management function (SMF) 194, and a user plane function (UPF) 195. The AMF 192 may be in communication with a unified data management (UDM) 196. The AMF 192 is a control node that handles signaling between the UE 104 and the core network 190. Generally speaking, the AMF 192 provides QoS flow and session management. All user Internet Protocol (IP) packets are passed through the UPF 195. The UPF 195 provides UE IP address allocation and other functions. The UPF 195 is connected to the IP services 197. The IP services 197 may include the Internet, an intranet, an IP multimedia subsystem (IMS), PS streaming services, and / or other IP services.

[0059] A base station may include and / or be referred to as a gNB, a Node B, an eNB, an access point, a base transceiver station, a radio base station, a radio transceiver, a transceiver function, a basic service set (BSS), an extended service set (ESS), a transmit reception point (TRP), or some other suitable terminology. Base station 102 provides an access point for UE 104 to EPC 160 or core network 190. Examples of UE 104 include a cellular phone, a smartphone, a Session Initiation Protocol (SIP) phone, a laptop, a personal digital assistant (PDA), a satellite radio, a global positioning system, a multimedia device, a video device, a digital audio player (e.g., an MP3 player), a camera, a game console, a tablet device, a smart device, a wearable device, a vehicle, an electric meter, a gas pump, a large or small kitchen appliance, a healthcare device, an implant, a sensor / actuator, a display, or any other similarly functional device. Some UEs 104 may be referred to as IoT devices (e.g., a parking meter, a gas pump, an oven, a vehicle, a heart monitor, etc.). UE 104 may also be referred to as a station, a mobile station, a subscriber station, a mobile unit, a subscriber unit, a wireless unit, a remote unit, a mobile device, a wireless device, a wireless communication device, a remote device, a mobile subscriber station, an access terminal, a mobile terminal, a wireless terminal, a remote terminal, a handset, a user agent, a mobile client, a client, or some other suitable terminology.

[0060] Continue to refer to Figure 1 In certain aspects, the UE 104 is configured, for example, via an information element (IE) from the base station 102, to sweep an UL beam 182″ between the UE 104 and the base station 102 in response to detecting a trigger. Such configuration includes configuring the UE 104 with rules specifying the triggering condition and configuring the UE 104 to measure the DL beam 182′ from the base station 102 and report the measurement to the base station 102 before detection. Also before detection, the UE 104 begins receiving the prepared beam from the base station 102 on the DL beam 182′ that is not currently being used for DL data transmission (based on the measurement). After sweeping, the UE 104 begins receiving DL transmissions on one or more DL beams 182′ based on the swept UL beam 182″ that was successfully received by the base station 102. The UE 104 may perform the configuration, measurement, and sweeping using a UE sweeping component 142.

[0061] In a similar aspect, the base station 102 transmits an IE for the above configuration to the UE 104 on the active DL beam 182′. The base station 102 then transmits a reference signal, such as a channel state information reference signal (CSI-RS), on each DL beam 182′ to be measured by the UE 104. Upon receiving measurements for each DL beam 182′ from the UE 104 on one or more uplink beams 182″, the base station 102 may prepare certain beams 182′ for use based at least in part on these measurements, such as by transmitting a phase tracking reference signal (PTRS) on one or more DL beams 182′ (including DL beams 182′ not currently being used for DL transmission). Upon receiving an indication that the DL transmission was unsuccessful, such as by receiving a NACK on one or more prepared beams 182″ in the uplink from the UE 104, the base station 102 switches the DL transmission to the one or more prepared beams 182′. The base station 102 may use the base station sweep component 144 to perform the functions described in this paragraph.

[0062] In other similar aspects, the role of the sweeping entity can be switched between the base station 102 and the UE 104. In such aspects, the base station 102 transmits configuration IEs (including measurement configuration) and instructions to the UE 104, such as a sounding reference signal (SRS) configuration and instructions for causing the UE 104 to transmit the SRS across multiple UL beams 182″. The base station 102 measures each uplink beam 182″ carrying the SRS and prepares additional DL beams 182′ as described above. Subsequently, when the base station 102 detects a beam sweeping trigger condition, the base station sweeps across the prepared DL beams 182′. The base station 102 can use the base station sweeping component 144 to perform the functions described in this paragraph.

[0063] In this switching role, UE 104 receives a configuration IE (including a measurement configuration) and instructions for UE 104, as described above. UE 104 then transmits a signal to be measured to base station 102 on UL beam 182″. Upon detection of a trigger condition by base station 102, UE 104 receives a sweep across DL beam 182′. In the event that UE 104 successfully receives the sweep, UE 104 then confirms the successful reception to base station 102 on UL beam 182″. After the sweep, UE 104 begins receiving DL transmissions on one or more DL beams 182′ based on the swept DL beam 182′ successfully confirmed to base station 102.

[0064] Although the following description may focus on 5G NR, the concepts described herein may be applicable to other similar areas such as LTE, LTE-A, CDMA, GSM, and other wireless technologies.

[0065] Figure 2A FIG200 is a diagram illustrating an example of a first subframe within a 5G / NR frame structure. Figure 2B is a diagram 230 illustrating an example of DL channels within a 5G / NR subframe. Figure 2C FIG250 is a diagram illustrating an example of a second subframe within a 5G / NR frame structure. Figure 2D 280 is a diagram illustrating an example of UL channels within a 5G / NR subframe. The 5G / NR frame structure can be FDD, where for a particular set of subcarriers (carrier system bandwidth), subframes within that subcarrier set are dedicated to either DL or UL; or TDD, where for a particular set of subcarriers (carrier system bandwidth), subframes within that subcarrier set are dedicated to both DL and UL. Figure 2A 、 2C In the example provided, the 5G / NR frame structure is assumed to be TDD, where subframe 4 is configured with slot format 28 (mostly DL) and subframe 3 is configured with slot format 34 (mostly UL), where D is DL, U is UL, and X is for flexible use between DL / UL. Although subframes 3 and 4 are shown as having slot formats 34 and 28, respectively, any particular subframe can be configured with any of the various available slot formats 0-61. Slot formats 0 and 1 are full DL and full UL, respectively. Other slot formats 2-61 include a mix of DL, UL, and flexible codewords. The UE is configured with the slot format (dynamically configured through DL control information (DCI) or semi-statically / statically configured through radio resource control (RRC) signaling) via the received slot format indicator (SFI). Note that the following description also applies to the 5G / NR frame structure for TDD.

[0066] Other wireless communication technologies may have different frame structures and / or different channels. A frame (10ms) may be divided into 10 equally sized subframes (1ms). Each subframe may include one or more time slots. A subframe may also include mini-slots, which may include 7, 4, or 2 symbols. Each time slot may include 7 or 14 symbols, depending on the time slot configuration. For time slot configuration 0, each time slot may include 14 symbols, while for time slot configuration 1, each time slot may include 7 symbols. The symbols on the DL may be cyclic prefix (CP) OFDM (CP-OFDM) symbols. The symbols on the UL may be CP-OFDM symbols (for high throughput scenarios) or discrete Fourier transform (DFT) spread OFDM (DFT-s-OFDM) symbols (also known as single carrier frequency division multiple access (SC-FDMA) symbols) (for power-limited scenarios; limited to single stream transmission). The number of time slots within a subframe is based on the time slot configuration and parameter design. For slot configuration 0, different parameter designs μ of 0 to 5 allow 1, 2, 4, 8, 16, and 32 slots per subframe, respectively. For slot configuration 1, different parameter designs 0 to 2 allow 2, 4, and 8 slots per subframe, respectively. Accordingly, for slot configuration 0 and parameter design μ, there are 14 symbols per slot and 2 per subframe. μ The subcarrier spacing and symbol length / duration vary depending on the parameter design. The subcarrier spacing can be equal to 2 μ *15kHz, where μ is parameter design 0 to 5. Thus, parameter design μ=0 has a subcarrier spacing of 15kHz, while parameter design μ=5 has a subcarrier spacing of 480kHz. The symbol length / duration is inversely related to the subcarrier spacing. Figures 2A-2D An example is provided for slot configuration 0 with 14 symbols per slot and parameter design μ = 2 with 4 slots per subframe. The slot duration is 0.25 ms, the subcarrier spacing is 60 kHz, and the symbol duration is approximately 16.67 μs.

[0067] A resource grid can be used to represent the frame structure. Each slot includes a resource block (RB) (also called a physical RB (PRB)) that extends over 12 consecutive subcarriers. The resource grid is divided into multiple resource elements (REs). The number of bits carried by each RE depends on the modulation scheme.

[0068] like Figure 2A As explained in

[15] , some REs carry reference (pilot) signals (RS) for UEs. RSs may include demodulation RSs (DM-RSs) for channel estimation at the UE (indicated as R for a specific configuration). x, where 100x is the port number, but other DM-RS configurations are possible) and a channel state information reference signal (CSI-RS). The RS may also include a beam measurement RS (BRS), a beam refinement RS (BRRS), and a phase tracking RS (PT-RS). Some examples of the techniques disclosed herein use the DM-RS of the physical downlink control channel (PDCCH) to assist in channel estimation (and ultimately demodulation of the user data portion) of the physical downlink shared channel (PDSCH).

[0069] Figure 2B An example of various DL channels within a subframe of a frame is illustrated. The physical downlink control channel (PDCCH) carries DCI within one or more control channel elements (CCEs), each CCE includes 9 RE groups (REGs), and each REG includes 4 consecutive REs in an OFDM symbol. The primary synchronization signal (PSS) may be within symbol 2 of a particular subframe of a frame. The PSS is used by the UE 104 to determine subframe / symbol timing and physical layer identity. The secondary synchronization signal (SSS) may be within symbol 4 of a particular subframe of a frame. The SSS is used by the UE to determine the physical layer cell identity group number and radio frame timing. Based on the physical layer identity and the physical layer cell identity group number, the UE can determine the physical cell identifier (PCI). Based on the PCI, the UE can determine the location of the aforementioned DM-RS. The physical broadcast channel (PBCH) carrying the master information block (MIB) can be logically grouped with the PSS and SSS to form a synchronization signal (SS) / PBCH block. The MIB provides the number of RBs in the system bandwidth and the system frame number (SFN). The Physical Downlink Shared Channel (PDSCH) carries user data, broadcast system information not transmitted through the PBCH (such as System Information Blocks (SIBs)), and paging messages.

[0070] As in Figure 2C As illustrated in FIG, some REs carry DM-RSs for channel estimation at the base station (indicated as R for one specific configuration, but other DM-RS configurations are possible). The UE may transmit DM-RSs for the physical uplink control channel (PUCCH) and DM-RSs for the physical uplink shared channel (PUSCH). The PUSCH DM-RS may be transmitted in the first or first two symbols of the PUSCH. The PUCCH DM-RS may be transmitted in different configurations depending on whether a short PUCCH or a long PUCCH is transmitted and on the specific PUCCH format used. The UE may transmit a sounding reference signal (SRS). The SRS may be transmitted in the last symbol of the subframe. The SRS may have a comb structure, and the UE may transmit the SRS on one of the comb teeth. The SRS may be used by the base station for channel quality estimation to enable frequency-dependent scheduling on the UL.

[0071] Figure 2D Examples of various UL channels within a subframe of a frame are illustrated. The PUCCH may be located as indicated in one configuration. The PUCCH carries uplink control information (UCI), such as scheduling requests, channel quality indicators (CQI), precoding matrix indicators (PMI), rank indicators (RI), and HARQ ACK / NACK feedback. The PUSCH carries data and may additionally be used to carry buffer status reports (BSRs), power headroom reports (PHRs), and / or UCI.

[0072] Figure 3 3 is a block diagram of a base station 310 and a UE 350 in communication in an access network. In the DL, IP packets from the EPC 160 may be provided to the controller / processor 375. The controller / processor 375 implements layer 3 and layer 2 functionality. Layer 3 includes the radio resource control (RRC) layer, and layer 2 includes the service data adaptation protocol (SDAP) layer, the packet data convergence protocol (PDCP) layer, the radio link control (RLC) layer, and the medium access control (MAC) layer. The controller / processor 375 provides RRC layer functionality associated with broadcasting of system information (e.g., MIB, SIB), RRC connection control (e.g., RRC connection paging, RRC connection establishment, RRC connection modification, and RRC connection release), inter-radio access technology (RAT) mobility, and measurement configuration for UE measurement reporting; PDCP layer functionality associated with header compression / decompression, security (ciphering, deciphering, integrity protection, integrity verification), and handover support functions; RLC layer functionality associated with delivery of upper layer packet data units (PDUs), error correction through ARQ, concatenation, segmentation and reassembly of RLC service data units (SDUs), resegmentation of RLC data PDUs, and reordering of RLC data PDUs; and MAC layer functionality associated with mapping between logical channels and transport channels, multiplexing of MAC SDUs onto transport blocks (TBs), demultiplexing of MAC SDUs from TBs, scheduling information reporting, error correction through HARQ, priority handling, and logical channel prioritization.

[0073] The transmit (TX) processor 316 and the receive (RX) processor 370 implement Layer 1 functionality associated with various signal processing functions. Layer 1, including the physical (PHY) layer, may include error detection on the transport channel, forward error correction (FEC) coding / decoding of the transport channel, interleaving, rate matching, mapping onto the physical channel, modulation / demodulation of the physical channel, and MIMO antenna processing. The TX processor 316 handles the mapping to the signal constellation based on various modulation schemes (e.g., binary phase shift keying (BPSK), quadrature phase shift keying (QPSK), M-phase shift keying (M-PSK), M-quadrature amplitude modulation (M-QAM)). The decoded and modulated symbols may then be split into parallel streams. Each stream may then be mapped to an OFDM subcarrier, multiplexed with a reference signal (e.g., a pilot) in the time and / or frequency domain, and then combined together using an inverse fast Fourier transform (IFFT) to produce a physical channel carrying a time-domain OFDM symbol stream. The OFDM stream is spatially precoded to generate multiple spatial streams. Channel estimates from a channel estimator 374 may be used to determine the coding and modulation schemes and for spatial processing. The channel estimates may be derived from a reference signal and / or channel condition feedback transmitted by the UE 350. Each spatial stream may then be provided to a different antenna 320 via a separate transmitter 318TX. Each transmitter 318TX may modulate an RF carrier with a corresponding spatial stream for transmission.

[0074] At the UE 350, each receiver 354RX receives a signal via its corresponding antenna 352. Each receiver 354RX recovers the information modulated onto the RF carrier and provides the information to a receive (RX) processor 356. The TX processor 368 and the RX processor 356 implement layer 1 functionality associated with various signal processing functions. The RX processor 356 may perform spatial processing on the information to recover any spatial streams destined for the UE 350. If multiple spatial streams are destined for the UE 350, they may be combined by the RX processor 356 into a single OFDM symbol stream. The RX processor 356 then converts the OFDM symbol stream from the time domain to the frequency domain using a fast Fourier transform (FFT). The frequency domain signal includes a separate OFDM symbol stream for each subcarrier of the OFDM signal. The symbols on each subcarrier, as well as the reference signal, are recovered and demodulated by determining the signal constellation point most likely transmitted by the base station 310. These soft decisions may be based on channel estimates calculated by the channel estimator 358. These soft decisions are then decoded and deinterleaved to recover the data and control signals originally transmitted on the physical channel by the base station 310. These data and control signals are then provided to the controller / processor 359, which implements layer 3 and layer 2 functionality.

[0075] The controller / processor 359 may be associated with a memory 360 that stores program codes and data. The memory 360 may be referred to as a computer-readable medium. In the UL, the controller / processor 359 provides demultiplexing between transport and logical channels, packet reassembly, cipher decoding, header decompression, and control signal processing to recover IP packets from the EPC 160. The controller / processor 359 is also responsible for error detection using ACK and / or NACK protocols to support HARQ operations.

[0076] Similar to the functionality described in conjunction with DL transmissions performed by the base station 310, the controller / processor 359 provides RRC layer functionality associated with system information (e.g., MIB, SIB) acquisition, RRC connection, and measurement reporting; PDCP layer functionality associated with header compression / decompression and security (ciphering, deciphering, integrity protection, integrity verification); RLC layer functionality associated with delivery of upper layer PDUs, error correction through ARQ, concatenation, segmentation, and reassembly of RLC SDUs, resegmentation of RLC data PDUs, and reordering of RLC data PDUs; and MAC layer functionality associated with mapping between logical channels and transport channels, multiplexing MAC SDUs onto TBs, demultiplexing MAC SDUs from TBs, scheduling information reporting, error correction through HARQ, priority handling, and logical channel prioritization.

[0077] Channel estimates derived by a channel estimator 358 from a reference signal or feedback transmitted by the base station 310 may be used by a TX processor 368 to select the appropriate coding and modulation scheme, and to facilitate spatial processing. The spatial streams generated by the TX processor 368 may be provided to different antennas 352 via separate transmitters 354TX. Each transmitter 354TX may modulate an RF carrier with a corresponding spatial stream for transmission.

[0078] UL transmissions are processed at the base station 310 in a manner similar to that described in conjunction with the receiver functionality at the UE 350. Each receiver 318RX receives a signal through its respective antenna 320. Each receiver 318RX recovers information modulated onto an RF carrier and provides the information to an RX processor 370.

[0079] The controller / processor 375 may be associated with a memory 376 that stores program codes and data. The memory 376 may be referred to as a computer-readable medium. In the UL, the controller / processor 375 provides demultiplexing between transport and logical channels, packet reassembly, cipher decoding, header decompression, and control signal processing to recover IP packets from the UE 350. The IP packets from the controller / processor 375 may be provided to the EPC 160. The controller / processor 375 is also responsible for error detection using ACK and / or NACK protocols to support HARQ operations.

[0080] Continue to refer to Figure 3 , and continuing with reference to the prior figures for context, in certain aspects, the UE 350 is configured, e.g., using an information element (IE) from the base station 310 using the controller processor 359, to: sweep the UL beam 182″ between the UE 350 and the base station 310 (e.g., sweep using TX 354 under control of the TX processor 368) in response to detecting a trigger (e.g., detecting using the controller / processor 359). Such configuration includes configuring the UE 350 (e.g., using the RX processor 356 and / or the controller processor 359) with rules specifying the trigger condition, and configuring the UE 350 to measure (e.g., using the 350 channel estimator 358) the DL beam 182′ from the base station 310 and report the measurement to the base station 310 (e.g., using the TX 354 and the TX processor 368) prior to detection. Also prior to detection, the UE The UE 350 begins receiving (e.g., using one or more RXs 354 and RX processors 356) the prepared beam from the base station 310 on a DL beam 182' that is not currently being used for DL data transfer (based on the measurements). After sweeping, the UE 350 begins receiving (e.g., using one or more RXs 354 and RX processors 356) DL transmissions on one or more DL beams 182' based on the swept UL beam 182" successfully received by the base station 310.

[0081] In a similar aspect, the base station 310 transmits (e.g., transmits using TX 318 under the control of the TX processor 316) the IE for the above configuration on the active DL beam 182′ to the UE 350. The base station 310 then transmits (e.g., transmits using TX 318 under the control of the TX processor 316) a reference signal, such as a channel state information reference signal (CSI-RS), on each DL beam 182′ to be measured by the UE 350. Upon receiving (e.g., receiving using RX 318 under control of RX processor 370) measurements for each DL beam 182′ from UE 104 on one or more uplink beams 182″, base station 310 may prepare (e.g., preparing using TX 318 under control of TX processor 316) certain beams 182′ for use based at least in part on these measurements, for example, by transmitting (e.g., transmitting using TX 318 under control of TX processor 316) a Phase Tracking Reference Signal (PTRS) on one or more DL beams 182′ (including DL beams 182′ not currently being used for DL transmission). Upon receiving (e.g., receiving using TX 318 under control of TX processor 316) measurements for each DL beam 182′ from UE 104 on one or more prepared beams 182″ in the uplink, base station 310 may prepare (e.g., preparing using TX 318 under control of TX processor 316) certain beams 182′ for use based at least in part on these measurements. When the base station 310 receives (e.g., receives using TX318 under the control of the TX processor 316) a NACK at 104 and receives (e.g., receives using RX318 under the control of the RX processor 370) an indication that the DL transmission is unsuccessful, the base station 310 switches the DL transmission (e.g., switches using TX318 under the control of the TX processor 316) to one or more prepared beams 182′.

[0082] In other similar aspects, the role of the sweeping entity can be switched between the base station 310 and the UE 350. In such aspects, the base station 310 transmits (e.g., using TX318 under control of the TX processor 316) configuration IEs (including measurement configurations) and instructions to the UE 350, such as sounding reference signal (SRS) configurations and instructions for causing the UE 350 to transmit SRS across multiple UL beams 182″. The base station 310 measures (e.g., using the channel estimator 374) each uplink beam 182″ carrying the SRS and prepares (e.g., using the TX processor 316) additional DL beams 182′, as described above. Subsequently, when the base station 310 detects (e.g., using RX318 under control of the RX processor 370) a beam sweeping trigger condition, the base station sweeps across the prepared DL beams 182′ (e.g., using TX318 under control of the TX processor 316).

[0083] In this switching role, UE 350 receives (e.g., using RX 354 and RX processor 356) a configuration IE (including the measurement configuration) and instructions for UE 350, as described above. UE 350 then transmits (using TX354 under control of TX processor 368) the signal to be measured to base station 310 on UL beam 182″. Upon detection of the triggering condition by base station 102, UE 104 receives (using RX 354 and RX processor 356) the sweep across DL beam 182′. In the event that UE 350 successfully receives the sweep, UE 350 then acknowledges (using TX354 under control of TX processor 368) the successful reception to base station 310 on UL beam 182″. After sweeping, the UE 104 begins receiving (using the RX 354 and the RX processor 356 ) DL transmissions on one or more DL beams 182 ′ based on the successful acknowledgement of the swept DL beam 182 ′ to the base station 310 .

[0084] Reference Figure 4 , and continuing with reference to the preceding figures for context, a conceptual representation of transmissions between a base station 180 (also referred to in this example as a "gNB") and a UE 184 is shown according to an example of the techniques disclosed herein. In the continuing example, the UE 184 and the gNB 180 are initially connected in a URLLC usage scenario under semi-persistent scheduling (SPS), as indicated by two repetitions of a PDSCH 422a. One PDSCH 422a is carried on beam 411a in the downlink to the UE 184, while the other PDSCH 422a is carried on beam 412a in the downlink to the UE 184. The UE 184 acknowledges successful reception of each repetition of the PDSCH 422a by first transmitting an ACK in each of the two repetitions of the PUCCH 452a on beams 411a and 412a in the uplink.

[0085] Reference Figure 5 , and continuing with reference to the previous figures for context, a flow chart of a wireless communication method 500 according to an example of the technology disclosed herein is shown. In such a method 500, the UE 184 receives conditions for sweeping beams between the base station 180 and the UE 184 (block 510). These conditions include beam sweeping triggering rules and a beam measurement configuration for measuring at least one characteristic of each beam on the downlink.

[0086] In the continuing example, the triggering rule and beam measurement configuration are carried as an information element (IE) in a radio resource control (RRC) level message, in particular as part of an RRCReconfiguration (RRCR) 432b on the downlink via beam 411b. The RRCR 432b includes a CSI-MeasConfig IE, an example of which is shown in Table 1. In the example of Table 1, the conditions include a "beamSweepingUponNack" flag for DL Traffic. The flag can take the Boolean values "true" (beam sweeping is enabled) and false (beam sweeping is disabled). The conditions include a triggering rule that is triggered upon detection of K consecutive unsuccessful receptions of downlink transmissions on the physical channel carried on the beam by the UE. In the continuing example, K can take an integer value from 1 to 12. The specific value of K is determined at least in part based on the reliability level required for the connection. These conditions also include an "Origin" indicator for sweeps initiated by UE 184 and sweeps initiated by gNB 180. Note that in the continued example, beam sweeping by the UE only occurs if the "beamSweepingUponNack" flag is "true" and "Origin" indicates "UE Orginated", "UL Beam Sweeping". In the continued example, these conditions are both true, and K = 1.

[0087]

[0088] Table 1

[0089] In some examples of the techniques disclosed herein, the IE for beam sweeping may be carried in other RRC-level messages, such as RRCSetup, RRCResume, and System Information Block (SIB) SIB2 or SIB3. More generally, the IE for beam sweeping may be carried in any RRC-level message without the need for an IE as part of, for example, CSI-MeasConfig as used herein—but note that CSI-MeasConfig carries IEs for beam measurement configuration, e.g., whether the measurement is performed on a zero-power (“zp”) or non-zero-power (“nzp”) signal from base station 180. Even more generally, the beam sweeping IE may be carried in a MAC-Control Element (MAC-CE) or DCI.

[0090] In addition, the techniques disclosed herein can control the time period for which a given set of measurement results remains valid for beam sweeping, the order of beams to be swept, and the number of beams to be swept. In the continuing example, the sweeping order is the order of the transmission configuration indicator (TCI) status reports - the order of the TCI states that have been used for PDSCH or PUSCH and the strongest reported TCI state in descending order. In the continuing example, the measurement results are valid for 3 milliseconds (e.g., three cycles) and only four beams (411, 412, 413, and 414) of the five available beams will be swept. In general, each enable / disable flag, K, order, number of beams, measurement validity time, and beam order can be sent as IEs or can be system parameters set in the UE 184 and gNB through other means (such as a backchannel or as part of manufacturing).

[0091] Reference Figure 9 , and continuing with the previous figures for context, there is shown a UE 350 for wireless communication according to an example of the technology disclosed herein. The UE 350 includes a UE sweep component 142, as described above in conjunction with Figure 3 The UE sweep component 142 includes a receiving component 142a. In some examples, the receiving component 142a receives a condition for sweeping a beam between the base station 180 and the UE 184. Accordingly, the receiving component 142a can provide a means for causing the UE 184 to receive the condition for sweeping a beam between the base station 180 and the UE 184.

[0092] UE 184 measures at least one characteristic of each beam according to the measurement configuration when the beam sweep condition is received (block 530). In the continuing example, UE 184 measures the CSI-RS swept across beams 411c, 412c, 413c, 414c, and 415c in the downlink according to the CSI-MeasConfig received in RRCR 432b, resulting in the results shown in Table 2.

[0093]

[0094] Table 2

[0095] Refer again Figure 9 UE sweep component 142 includes a measurement component 142b. In some examples, measurement component 142b measures at least one characteristic of each beam according to a measurement configuration. Accordingly, measurement component 142b can provide means for measuring at least one characteristic of each beam according to the measurement configuration.

[0096] After the measurement, UE 184 detects a beam sweeping trigger according to the triggering rules (block 570). In the continued example, with K=1, in the cycle after the measurement is completed, UE 184 fails to receive and decode PDSCH 422e on either beam 411e or 412e. In other examples, triggers such as a decoded bit error rate over a time window, a PER not remaining at a target level, an SRS indicating a signal strength below a threshold at the gNB, and a gNB-initiated beam change due to load can be used.

[0097] Refer again Figure 9 UE sweep component 142 includes a detection component 142c. In some examples, detection component 142c detects beam sweep triggering according to a triggering rule. Accordingly, measurement component 142b may provide a means for detecting beam sweep triggering according to the triggering rule.

[0098] In response to detecting the trigger, UE 184 sweeps the beams on the uplink based on the measurement (block 580). In the continuing example, four beams (411, 412, 413, and 414) with the strongest CQI of the five measured beams are swept. In the continuing example, "sweeping" includes transmitting a NACK in the PUCCH on each beam 411f, 412f, 413f, and 414f in sequence in the uplink. In some examples, the sweep is performed on an unblocked beam (in the continuing example, the beam currently used for data transmission is blocked). In the case where the system (both UE 184 and base station 180) determines that the error occurred due to blocking, it would be useful to exclude the blocked beam from the sweep. In the case where UE 184 or base station 180 cannot detect whether the error occurred due to blocking, it is appropriate to sweep all beams.

[0099] Refer again Figure 9 , UE sweeping component 142 includes sweeping component 142d. In some examples, sweeping component 142c sweeps the beam on the uplink based on the measurement. Accordingly, sweeping component 142c can provide means for sweeping the beam on the uplink based on the measurement.

[0100] Reference Figure 6 , and continuing with the previous figures for context, a flow chart of a wireless communication method 600 according to an example of the technology disclosed herein is shown. In such a method 600, blocks 510, 530, 570, and 580 are as combined Figure 5 Executed as described.

[0101] In such a method 600, after measuring at least one characteristic of each beam according to the measurement configuration and before detecting a trigger, the UE 184 transmits the measured at least one characteristic of each beam to the base station (block 640). In the continuing example, the UE 184 transmits the results shown in Table 2 along with an ACK as part of PUCCH 451d on beam 411d in the uplink to the base station 180.

[0102] In some examples, the measured characteristics are transmitted in other messages (such as RRC measurement reports). In some cases, the UE 184 may report the beam sets in a given order, but the base station 180 may configure the beam sweeping pattern within any subset or the full set and in any order. Consider two cases - case 1: the UE 184 does not transmit SRS when receiving CSI-RS; and case 2: the UE 184 transmits SRS in the uplink during the same time window in which the UE 184 receives and measures CSI-RS. In case 1, the base station 180 will select a subset of the reported CSI-RS set for the beam sweeping pattern. In case 2, the base station 180 may select any beam among those beams used for CSI-RS and SRS measurements. Therefore, in case 2, the UE 184 may receive a beam sweeping pattern that does not include any beam reported via PUCCH.

[0103] Refer again Figure 9 ,exist Figure 6 In some examples, the UE sweep component 142 includes a transmitting component 142e. In some examples, the transmitting component 142e transmits the measured at least one characteristic of each beam to the base station. Accordingly, the transmitting component 142e can provide a means for transmitting the measured at least one characteristic of each beam to the base station.

[0104] UE 184 receives an acknowledgment of successful receipt of the transmitted beam characteristic measurement from base station 180 (block 650). In some examples, this acknowledgment is received in conjunction with Figure 5 In some examples, the acknowledgment is carried on the DCI in series with the enable / disable flag described. In some examples, the acknowledgment is used by the base station 180 to adjust the number, order, or identity of beams to be swept by the UE 184 upon detection of the triggering condition. In a continuing example, the acknowledgment is sent by the base station 180 in the downlink using beam 411d in message 442d. In some examples, the message 442d includes an IE that rearranges the order of beams used, omits some beams, or replaces other beams based on information obtained by the network / base station 180 and the strategy implemented in the network / base station 180. In other examples, no acknowledgment is sent, and the UE 184 assumes that the four strongest beams are to be swept upon detection of the trigger based on the received beam sweeping conditions.

[0105] In some examples, in addition to the TCI state ID, the number of TCI states, and the order, another parameter of the beam sweeping pattern is the duration per TCI state. For example, consider a UE close to the base station and uplink beam sweeping occurs by the UE transmitting a 1-symbol PUCCH. In another scenario, the UE may be far away from the base station and the UE may be required to transmit the same PUCCH format in 2 symbols. To cover all scenarios, the following uplink beam sweeping patterns are considered: TCI state ID 1, duration 1 symbol; TCI state ID 2, duration 1 symbol; TCI state ID 3, duration 2 symbols; TCI state ID 4, duration 2 symbols; and TCI state ID 5, duration 1 symbol.

[0106] Refer again Figure 9 ,exist Figure 6 In some examples, the UE sweep component 142 includes a second receiving component 142f. In some examples, the second receiving component 142f receives an acknowledgment of successful receipt of the transmitted beam characteristic measurement from the base station 180. Accordingly, the transmitting component 142e may provide a means for receiving an acknowledgment of successful receipt of the transmitted beam characteristic measurement from the base station 180.

[0107] UE 184 receives a third phase tracking reference signal (PTRS) from base station 180 on at least one reported beam after the second reception (block 660). In some examples, base station 180 uses the PTRS transmitted on each of the multiple beams as a way to prepare UE 184 to use currently unused beams for both sweeping and data transfer upon detecting a trigger.

[0108] In some examples, when base station 180 transmits a DL PTRS for a given TCI state, this means that the DL TCI state is "ready" and the final TCI state switch from the TCI state currently used for data transmission to the new TCI state can be completed relatively quickly. Similarly, in the case where UE 184 is requested to transmit a PTRS within a given UL TCI state, then the UL beam is "ready."

[0109] Refer again Figure 9 ,exist Figure 6 In an example, the UE sweep component 142 includes a third receiving component 142g. In some examples, the third receiving component 142g receives a phase tracking reference signal (PTRS) from the base station 180 on the at least one reported beam after the second reception. Accordingly, the transmitting component 142e can provide a means for receiving a phase tracking reference signal (PTRS) from the base station 180 on the at least one reported beam after the second reception.

[0110] Reference Figure 7 , and continuing with the previous figures for context, a flow chart of a wireless communication method 700 according to an example of the technology disclosed herein is shown. In such a method 700, blocks 510, 530, 570, and 580 are as combined Figure 5 In such a method 700, prior to receiving the conditions, the UE 184 requests the conditions for sweeping a beam of a physical channel between a base station of the network and the UE (block 720). In such a method 700, the UE receives the conditions for sweeping a beam between a base station of the network and the UE in response to the request. The request may be triggered by the service type and by how the current quality of service meets the service type requirements.

[0111] Refer again Figure 9 ,exist Figure 7 In some examples, the UE sweep component 142 includes a request component 142h. In some examples, the request component 142h requests conditions for sweeping a beam of a physical channel between a base station of the network and the UE. Accordingly, the transmitting component 142e may provide a means for requesting conditions for sweeping a beam of a physical channel between a base station of the network and the UE.

[0112] Reference Figure 8 , and continuing with the previous figures for context, a flow chart of a wireless communication method 800 according to an example of the technology disclosed herein is shown. In such a method 800, blocks 510, 530, 570, and 580 are as combined Figure 5 In such a method 800, each swept beam carries a physical uplink control channel (PUCCH) of the UE, the PUCCH including an information element related to the detected trigger. In such a method 800, the UE fourth receives data on one or more physical downlink shared channels (PDSCHs) via one or more beams corresponding to the beams on which the base station successfully received the information element (block 890).

[0113] In the continued example, each of beams 411f, 412f, 413f, and 414f (four of the five measured beams) carries a NACK on PUCCH 451f in the uplink. Uplink-downlink channel symmetry applies in the continued example, and beams 411f and 412f are not received by base station 180. However, base station 180 does receive PUCCH 451f carrying a NACK on beams 413f and 414f in the uplink (K=1 triggering condition). As a result, base station 180 transmits DCI 462g on at least beam 413g in the downlink and transmits SPS PDSCH 422g across the currently active beams 413g and 414g, and UE 184 receives both the DCI 462g and the SPS PDSCH 422g. UE 184 may then use ACK on PUCCH 451g in the uplink on beams 413g and 414g to acknowledge successful reception and decoding of SPS PDSCH 422g. In the absence of further obstruction or interference, the base station will continue to transmit subsequent SPS PDSCH (e.g., SPS PDSCH 422h) on beams 413 and 414 (e.g., beams 413h and 414h) in the downlink. In some examples, UE 184 prepares its receiver to receive retransmissions or DCI via the same beam sweeping pattern (or a subset thereof). Thus, the UE 184 receiver expects beam 1 at time t0, beam 2 at time t1=t0+1 symbol, beam 3 at t2=t1+1 symbol, and so on. The base station receives the first correct version of the PUCCH with a NACK via TCI State ID (Beam) - see block 580 above. In the continuing example, there is no point in performing retransmission and DCI transmission via the blocked beam, and then the base station 180 transmits beam 3 at t2 (the base station 180 knows that the UE expects this transmission of TCI state ID 3 at this moment).

[0114] Refer again Figure 9 ,exist Figure 8 In an example, the UE sweep component 142 includes a fourth receiving component 142g. In some examples, the fourth receiving component 142g receives data on one or more physical downlink shared channels (PDSCHs) via one or more beams corresponding to the beams on which the base station successfully received the information element. Accordingly, the transmitting component 142e may provide a means for receiving data on one or more physical downlink shared channels (PDSCHs) via one or more beams corresponding to the beams on which the base station successfully received the information element.

[0115] Reference Figure 10, and continuing with the previous figures for context, a flow chart of a wireless communication method 1000 according to an example of the technology disclosed herein is shown. In such a method, a base station 180 first transmits to a UE of a network a condition for sweeping a beam between the UE 814 and the base station 180 (block 1010). Similar to Figure 5 184, but from the perspective of the base station 180 rather than the UE 184, these conditions include beam sweeping triggering rules, and beam measurement configuration for measuring at least one characteristic of each beam on the downlink. In the continued example, the triggering rules and beam measurement configuration are carried as IEs as part of the RRCR 432b on the downlink via beam 411b. The RRCR 432b includes the CSI-MeasConfig IE of Table 1. As mentioned above, the "beamSweepingUponNack" flag is "true", "Origin" indicates "UE originating", "UL beam sweeping", and K=1. The sweeping order is the order in which the transmission configuration indicator TCI status is reported - the order of the TCI status that has been used for PDSCH or PUSCH and the TCI status that is reported most strongly in descending order. In the continued example, the measurement results are valid for 3 milliseconds (three cycles) and only four beams (411, 412, 413 and 414) of the five available beams will be swept.

[0116] Reference Figure 13 , and continuing to refer to the previous figures for context, a base station 310 for wireless communication according to an example of the technology disclosed herein is shown. The base station 310 includes a base station sweep component 144, as described above in conjunction with Figure 3 The base station sweeping component 144 includes a first transmitting component 144a. In some examples, the first transmitting component 144a first transmits a condition for sweeping a beam between the UE 184 and the base station 102 to a UE of the network. Accordingly, the first transmitting component 144a can provide a means for first transmitting a condition for sweeping a beam between the UE 184 and the base station 102 to a UE of the network.

[0117] The base station 180 transmits a reference signal on the beam for the second time on the downlink after the first transmission (block 1020). In the continuing example, the base station 180 transmits a CSI-RS swept across beams 411c, 412c, 413c, 414c, and 415c in the downlink for the second time according to the CSI-MeasConfig transmitted in the RRCR 432b. Figure 13, the base station sweep component 144 includes a second transmitting component 144b. In some examples, the second transmitting component 144b transmits a reference signal on the beam on the downlink for the second time after the first transmission. Accordingly, the second transmitting component 144b can provide means for transmitting the reference signal on the beam on the downlink after the first transmission.

[0118] The base station 180 first receives downlink beam measurements according to the beam measurement configuration from the UE 184 in response to the first transmission and the second transmission (block 1030). In the continuing example, the UE 814 transmits the results shown in Table 2 along with an ACK as part of the PUCCH 451d to the base station 180 on beam 411d in the uplink. Figure 13 , the base station sweep component 144 includes a receiving component 144c. In some examples, the receiving component 144c first receives a downlink beam measurement according to the beam measurement configuration from the UE 184 in response to the first transmission and the second transmission. Accordingly, the first receiving component 144c may provide means for first receiving a downlink beam measurement according to the beam measurement configuration from the UE 184 in response to the first transmission and the second transmission.

[0119] The base station 180 prepares at least one beam not currently used in the downlink in response to the first reception (block 1040). In some examples, the base station 180 uses the PTRS transmitted on each of the plurality of beams as a way to prepare the UE 184 to use the currently unused beam for both sweeping and data transfer upon detecting the trigger. Figure 13 The base station sweep component 144 includes a preparation component 144d. In some examples, the preparation component 144d prepares at least one beam not currently used in the downlink in response to the first reception. Accordingly, the preparation component 144d can provide a means for preparing at least one beam not currently used in the downlink in response to the first reception.

[0120] The base station 180 secondly receives an indication that a trigger has been detected at the UE according to the triggering rule on at least one of the prepared beams swept by the UE (block 1050). In the continued example, four of the five measured beams (411, 412, 413, and 141) with the strongest CQI are swept by the UE 184. In the continued example, "sweeping" includes transmitting a NACK in the PUCCH 451f on each of the beams 411f, 412f, 413f, and 414f in sequence in the uplink. Figure 13, the base station sweeping component 144 includes a second receiving component 144e. In some examples, the second receiving component 144e receives an indication that a trigger has been detected at the UE according to the triggering rule on at least one prepared beam swept by the UE. Accordingly, the second receiving component 144e can provide a means for receiving an indication that a trigger has been detected at the UE according to the triggering rule on at least one prepared beam swept by the UE.

[0121] Base station 180 transmits at least one physical channel to UE 184 on at least one prepared beam (block 1060). In the continuing example, base station 180 transmits DCI 462g on at least beam 413g in the downlink and SPS PDSCH 422g across currently active beams 413g and 414g after receiving PUCCH 451f carrying a NACK on beams 413f and 414f in the uplink (K=1 triggering condition). UE 184 can then use an ACK on PUCCH 451g in the uplink on beams 413g and 414g to acknowledge successful reception and decoding of SPS PDSCH 422g. In the absence of further obstruction or interference, the base station will continue to transmit subsequent SPS PDSCHs (e.g., SPS PDSCH 422h) on beams 413 and 414 (e.g., beams 413h and 414h) in the downlink.

[0122] Reference Figure 13 The base station sweep component 144 includes a third transmitting component 144f. In some examples, the third transmitting component 144f transmits at least one physical channel to the UE on at least one prepared beam. Accordingly, the third transmitting component 144f can provide means for transmitting at least one physical channel to the UE on at least one prepared beam.

[0123] Reference Figure 11 , and continuing with the previous figures for context, a flow chart of a wireless communication method 1100 according to an example of the technology disclosed herein is shown. In such a method 1100, blocks 1010, 1020, 1030, 1040, 1050, and 1060 are as combined Figure 10 In such method 1100, base station 180 thirdly receives from UE 184 a condition for sweeping a beam of a physical channel between base station 180 and UE 184 (block 1170). In such method 700, the UE receiving the condition for sweeping a beam between a base station of the network and the UE is responsive to the request.

[0124] Reference Figure 13, the base station sweeping component 144 includes a third receiving component 144g. In some examples, the third receiving component 144g receives a request from the UE 184 for conditions for sweeping a beam of a physical channel between the base station 180 and the UE 184. Accordingly, the third receiving component 144g can provide a means for receiving a request from the UE 184 for conditions for sweeping a beam of a physical channel between the base station 180 and the UE 184.

[0125] Reference Figure 12 , and continuing with the previous figures for context, a flow chart of a wireless communication method 1200 according to an example of the technology disclosed herein is shown. In such a method 1200, blocks 1010, 1020, 1030, 1040, 1050, and 1060 are as combined Figure 10 In such a method 1200, the base station 180 fourthly transmits data on one or more physical downlink shared channels (PDSCHs) via one or more beams corresponding to the beams on which the base station 180 successfully received the information element (block 1280). In such a method, each second received beam carries a physical uplink control channel (PUCCH) of the UE, the PUCCH including an information element related to a trigger detected according to the sweep trigger rule.

[0126] In the continued example, each of beams 411f, 412f, 413f, and 414f (four of the five measured beams) carries a NACK on PUCCH 451f in the uplink from UE 184 to base station 180. Uplink-downlink channel symmetry applies in the continued example, and beams 411f and 412f are not received by base station 180. However, base station 180 does not receive PUCCH 451f carrying a NACK on beams 413f and 414f in the uplink (K=1 triggering condition). As a result, base station 180 transmits DCI 462g on at least beam 413g in the downlink and transmits SPS PDSCH 422g across the currently active beams 413g and 414g, and UE 184 receives both the DCI 462g and the SPS PDSCH 422g. UE 184 may then use ACK on PUCCH 451g in the uplink to acknowledge successful reception and decoding of SPS PDSCH 422g on beams 413g and 414g. In the absence of further obstruction or interference, the base station may continue to transmit subsequent SPS PDSCHs (e.g., SPS PDSCH 422h) on beams 413 and 414 (e.g., beams 413h and 414h) in the downlink.

[0127] Reference Figure 13, the base station sweep component 144 includes a fourth transmitting component 144h. In some examples, the fourth transmitting component 144h transmits data on one or more physical downlink shared channels (PDSCHs) via one or more beams corresponding to the beams on which the base station 180 successfully received the information element. Accordingly, the fourth transmitting component 144h can provide a means for transmitting data on one or more physical downlink shared channels (PDSCHs) via one or more beams corresponding to the beams on which the base station 180 successfully received the information element.

[0128] Reference Figure 14 , and continuing with reference to the previous figures for context, a second conceptual representation of transmissions between base station 180 (also referred to in this example as "gNB") and UE 184 is shown according to an example of the presently disclosed techniques. In the second continued example, UE 184 and gNB 180 are initially connected in a URLLC usage scenario under semi-persistent scheduling (SPS), as indicated by two copies of PUSCH 1491a. One copy of PUSCH 1491a is carried on beam 1411a in the uplink from UE 184 to base station 180, while the other copy of PUSCH 1491a is carried on beam 1412a in the uplink from UE 184.

[0129] Reference Figure 15 , and continuing with reference to the preceding figures for context, a flow chart of a wireless communication method 1500 according to an example of the technology disclosed herein is shown. In such a method, a base station 180 transmits a beam sweep configuration specifying a reference signal to a UE 184 (block 1510). In a second continuing example, the reference signal specification is carried as an information element (IE) in a radio resource control level (RRC level) message, particularly as part of an RRCReconfiguration (RRCR) 1431b on the downlink via beam 1411b. The RRCR 1431b includes an SRS-Config IE that is combined with a reference signal information element (IE) to specify a reference signal. Figure 5The beam sweeping IE described above is modified in a manner similar to that described in Table 1, an example of which is shown in Table 3. In the example of Table 3, the conditions include a "beamSweepingUponNack" flag for DL traffic. This flag can take the Boolean values of "true" (beam sweeping is enabled) and "false" (beam sweeping is disabled). The conditions include an "Origin" indicator for sweeps initiated by UE 184 and those initiated by gNB 180. In the second continued example, the "Origin" flag is set to "gNB-initiated." The conditions include a trigger rule that is triggered upon detecting K consecutive unsuccessful receptions by the UE of downlink transmissions on the physical channel carried on the beam. K can take an integer value from 1 to 12. The specific value of K is determined at least in part based on the required reliability level of the connection. Note that for the sweep in the second continued example, K is not used because the "Origin" flag is set to "gNB-initiated." Note that beam sweeping by the UE only occurs if the "beamSweepingUponNack" flag is "true" and "Origin" indicates "gNB-initiated," UL beam sweeping. In the second continued example, beam sweeping is enabled and the "Origin" flag is set to "gNB-initiated." K is not specified because the base station 180 triggering criteria (a single session not receiving PUSCH when expected—similar to K=1) does not need to be communicated to the UE 184.

[0130]

[0131] Table 3

[0132] In some examples of the techniques disclosed herein, the IE for beam sweeping may be carried in other RRC-level messages, such as RRC setup, RRC recovery, and system information blocks (SIBs) SIB2 or SIB 3. More generally, the IE for beam sweeping may be carried in any RRC-level message without requiring the IE to be part of an SRS-Config, such as used herein.

[0133] In addition, the techniques disclosed herein can control the order of beams used for sweeping, as well as the number of beams to be swept. In a second continued example, the order of sweeping and the number of beams to be swept are specified in the SRS-Config. In the second continued example, all five available beams will be swept on the uplink from UE 184. In general, each of the enable / disable flag, K, order, number of beams, and beam order can be sent as an IE, or can be a system parameter set in the UE 184 and gNB through other means, such as a backhaul or sidelink channel, or as part of manufacturing.

[0134] Reference Figure 19 , and continuing to refer to the previous figures for context, a base station 310 for wireless communication according to an example of the technology disclosed herein is shown. The base station 310 includes a base station sweep component 144 ', as described above in conjunction with Figure 3 The base station sweeping component 144' includes a transmitting component 144a'. In some examples, the transmitting component 144a' transmits the beam sweeping configuration of the specified reference signal to the UE 184. Accordingly, the transmitting component 144a' can provide a means for transmitting the beam sweeping configuration of the specified reference signal to the UE 184.

[0135] Base station 180 measures at least one characteristic of each of a plurality of beams of a physical channel on the uplink from the UE to the base station, and each beam includes a designated reference signal (block 1530). These beams include each beam currently used for communication between the base station and the UE, as well as a plurality of beams not currently used for downlink data transfer to the UE. In a second continued example, base station 180 measures SRSs swept across beams 1411c, 1412c, 1413c, 1414c, and 1415c in the uplink, resulting in the results shown in Table 4.

[0136]

[0137] Table 4

[0138] Reference Figure 19 , and continuing to refer to the previous figures for context, a base station 310 for wireless communication according to an example of the technology disclosed herein is shown. The base station 310 includes a base station sweep component 144 ', as described above in conjunction with Figure 3 As described. The base station sweep component 144' includes a measurement component 144b'. In some examples, the measurement component 144b' measures at least one characteristic of each of a plurality of beams of a physical channel on an uplink from the UE to the base station, and each beam includes a designated reference signal. Accordingly, the measurement component 144b' may provide a means for measuring at least one characteristic of each of a plurality of beams of a physical channel on an uplink from the UE to the base station, and each beam includes a designated reference signal.

[0139] After the measurement, base station 180 detects a beam sweep trigger condition (block 1550). In a second, continued example, base station 180 does not receive the two copies of the expected PUSCH 1491e on beams 1411e and 1412e at the beginning of the second cycle and after having transmitted DCI 1461e. A single expected PUSCH that is not received when expected (similar to K=1) results in a detected trigger. In other examples, triggers such as a decoded bit error rate over a time window may be used.

[0140] Refer again Figure 19 , the base station sweeping component 144' includes a detection component 142c'. In some examples, the detection component 144c' detects a beam sweeping trigger condition after the measurement. Accordingly, the measurement component 144b' can provide a means for detecting a beam sweeping trigger condition after the measurement.

[0141] In response to the detection, the base station 180 sweeps a plurality of measured beams on the downlink to the UE based on the measurement and configuration (block 1560). In a second continued example, the base station sweeps five beams (1411f, 1412f, 1413f, 1414f, and 1415f) in order of strength. In the second continued example, "sweeping" includes transmitting DCI 1461f on the downlink on each beam in descending order of measured uplink power. Note that in both the uplink sweep and the downlink sweep, the base station 180 or UE 184 may use criteria other than decreasing power to sort some or all of the available beams for sweeping. For example, the base station 180 may exclude beams (e.g., 1411 and 1412) that are assumed to be blocked due to a failure of PUSCH on the uplink. As another example, the base station may exclude beams that are reserved for some other purpose.

[0142] Refer again Figure 19 , base station sweeping component 144' includes sweeping component 144d'. In some examples, sweeping component 144d' sweeps a plurality of measured beams on a downlink to the UE based on the measurement and configuration in response to the detection. Accordingly, measuring component 144b' may provide means for sweeping a plurality of measured beams on a downlink to the UE based on the measurement and configuration in response to the detection.

[0143] Reference Figure 16 , and continuing with the previous figures for context, a flow chart of a wireless communication method 1600 according to an example of the technology disclosed herein is shown. In such a method 1600, blocks 1510, 1530, 1550, and 1560 are as combined Figure 15 1411b in the downlink. Figure 19, the base station sweeping component 144' includes a receiving component 144e'. In some examples, the receiving component 144e' receives confirmation from the UE that the UE is configured according to the transmitted beam sweeping configuration before the measurement. Accordingly, the receiving component 144e' can provide a means for receiving confirmation from the UE that the UE is configured according to the transmitted beam sweeping configuration before the measurement.

[0144] Reference Figure 17 , and continuing with the previous figures for context, a flow chart of a wireless communication method 1700 according to an example of the technology disclosed herein is shown. In such a method 1700, blocks 1510, 1530, 1550, and 1560 are as combined Figure 15 In such a method 1700, after measuring, the base station prepares a plurality of beams that are not currently in use for sweeping upon detection of a beam sweeping trigger condition (block 1740). In some examples, the base station 180 uses a PTRS transmitted on each of the plurality of beams as a means for preparing the UE 184 to use the beams that are not currently in use for both sweeping and data transfer upon detection of a trigger.

[0145] Refer again Figure 19 The base station sweep component 144' includes a preparation component 144f'. In some examples, the preparation component 144' prepares multiple beams that are not currently in use for sweeping upon detection of a beam sweep trigger condition. Accordingly, the preparation component 144f' can provide a means for preparing multiple beams that are not currently in use for sweeping upon detection of a beam sweep trigger condition.

[0146] Reference Figure 18 , and continuing with the previous figures for context, a flow chart of a wireless communication method 1800 according to an example of the technology disclosed herein is shown. In such a method 1800, blocks 1510, 1530, 1550, and 1560 are as combined Figure 15 1414f. In such method 1800, base station 180 receives, from the UE, a second acknowledgment of a successful transmission on each of the plurality of swept beams after the sweep (block 1870). In such method 1800, base station 180 transmits data thirdly on one or more of the acknowledged beams (block 1880). In a second continued example, UE 184 retransmits PUSCH 1491e as PUSCH 1491g on beams 1413g and 1414g upon successfully receiving and decoding the swept signals on one or more of beams 1411f-1414f.

[0147] Refer again Figure 19, the base station sweep component 144' includes a second receiving component 144g'. In some examples, the second receiving component 144g' receives an acknowledgment of a successful transmission on each of the multiple swept beams from the UE after the sweep. Accordingly, the second receiving component 144g' may provide a device for receiving an acknowledgment of a successful transmission on each of the multiple swept beams from the UE after the sweep. The base station sweep component 144' also includes a third transmitting component 144h'. In some examples, the third transmitting component 144h' transmits data on one or more confirmed beams. Accordingly, the third transmitting component 144h' may provide a device for transmitting data on one or more confirmed beams.

[0148] Reference Figure 20 , and continuing with the previous figures for context, a flow chart of a wireless communication method 2000 according to an example of the technology disclosed herein is shown. In this method, the UE 184 receives a beam sweeping configuration of a specified reference signal from the base station 180 (block 2010). Similar to Figure 15 In the second continued example, the reference signal designation is carried in a radio resource control level (RRC level) message (IE), specifically as part of an RRCReconfiguration (RRCR) 1431b on the downlink via beam 1411b. The RRCR 1431b includes an SRS-Config IE that is combined with the SRS-Config IE. Figure 15 The beam sweeping IE is modified in a similar manner to that described in Table 3. In the second continued example, beam sweeping is enabled and the "Origin" flag is set to "gNB initiated". K is not specified because the base station 180 triggering criteria (single session of not receiving PUSCH when expected (similar to K=1)) does not need to be communicated to the UE 184.

[0149] Reference Figure 25 , and continuing with the previous figures for context, there is shown a UE 350 for wireless communication according to an example of the technology disclosed herein. The UE 350 includes a UE sweep component 142 ', as described above in conjunction with Figure 3 UE sweeping component 142′ includes receiving component 142a′. In some examples, receiving component 142a′ receives a beam sweeping configuration specifying a reference signal from base station 180. Accordingly, receiving component 142a′ can provide a means for receiving a beam sweeping configuration specifying a reference signal from base station 180.

[0150] UE 184 first transmits a designated reference signal to base station 180 on each of a plurality of beams of a physical channel, including each beam currently used for data transfer between base station 180 and UE 184 and a plurality of beams not currently used for data transfer from base station 180 to UE 184 (block 2020). In a second continued example, UE 184 transmits an SRS swept across beams 1411 c, 1412 c, 1413 c, 1414 c, and 1415 c to base station 180 (as configured in block 2010). Beams 1411 and 1412 are currently used between UE 184 and base station 180.

[0151] Refer again Figure 25 , the UE sweep component 142' includes a first transmitting component 142b'. In some examples, the first transmitting component 142b' transmits a designated reference signal to the base station 180 on each of a plurality of beams of a physical channel, including each beam currently used for data transfer between the base station 180 and the UE 184 and a plurality of beams not currently used for data transfer from the base station 180 to the UE 184. Accordingly, the first transmitting component 142b' may provide a means for transmitting the designated reference signal to the base station 180 on each of a plurality of beams of a physical channel, including each beam currently used for data transfer between the base station 180 and the UE 184 and a plurality of beams not currently used for data transfer from the base station 180 to the UE 184.

[0152] Based on the measurements and configuration, the UE 184 receives a plurality of transmitted beams swept on the downlink to the UE 184 for downlink data transfer from the base station to the UE (block 2030). In a second continued example, the UE 184 receives five beams (1411f, 1412f, 1413f, 1414f, and 1415f) swept in order of strength. In the second continued example, "sweeping" includes transmitting DCI 1461f on the downlink on each beam in descending order of measured uplink power.

[0153] Refer again Figure 25 , the UE sweep component 142' includes a second receiving component 142c'. In some examples, the second receiving component 142c' receives a plurality of transmitted beams swept on the downlink to the UE 184 based on the measurement and configuration for downlink data transfer from the base station to the UE. Accordingly, the second receiving component 142c' can provide a means for receiving a plurality of transmitted beams swept on the downlink to the UE 184 based on the measurement and configuration for downlink data transfer from the base station to the UE.

[0154] Reference Figure 21, and continuing with the previous figures for context, a flow chart of a wireless communication method 2100 according to an example of the technology disclosed herein is shown. In such a method 2100, blocks 2010, 2020, and 2030 are as combined Figure 20 In such method 2100, UE 184 determines that the second subset of received beams successfully delivered data from base station 180 to UE 184 (block 2140). UE 184 acknowledges to base station 180 the successful delivery of data from base station 180 to UE 184 on the subset of received beams (block 2150). In a second continued example, UE 184 retransmits PUSCH 1491e as PUSCH 1491g on beams 1413g and 1414g upon successfully receiving and decoding swept signals on one or more of beams 1411f-1414f.

[0155] Refer again Figure 25 , the UE sweep component 142' includes a determining component 142d'. In some examples, the determining component 142d' determines that the second subset of received beams successfully delivered data from the base station 180 to the UE 184. Accordingly, the determining component 142d' may provide a means for determining that the second subset of received beams successfully delivered data from the base station 180 to the UE 184. In addition, the UE sweep component 142' includes a confirming component 142e'. In some examples, the confirming component 142e' confirms to the base station 180 the successful delivery of data from the base station 180 to the UE 184 on the subset of received beams. Accordingly, the confirming component 142e' may provide a means for confirming to the base station 180 the successful delivery of data from the base station 180 to the UE 184 on the subset of received beams.

[0156] Reference Figure 22 , and continuing with the previous figures for context, a flow chart of a wireless communication method 2200 according to an example of the technology disclosed herein is shown. In such a method 2200, blocks 2010, 2020, and 2030 are as combined Figure 20 In such method 2200, UE 184 transmits a second confirmation to base station 180 prior to the first transmission that UE 184 is configured according to the received beam sweep configuration (block 2260). In the second continued example, UE 184 transmits RRCR confirmation 1432b on beam 1411b in the uplink, which confirms that UE 184 is configured according to RRCR 1431b sent by base station 180 on beam 1411b in the downlink earlier in the cycle.

[0157] Refer again Figure 25 , the UE sweeping component 142′ includes a second transmitting component 142f′. In some examples, the second transmitting component 142f′ transmits a confirmation to the base station 180 that the UE 184 is configured according to the received beam sweeping configuration before the first transmission. Accordingly, the second transmitting component 142f′ can provide a means for transmitting a confirmation to the base station 180 that the UE 184 is configured according to the received beam sweeping configuration before the first transmission.

[0158] Reference Figure 23 , and continuing with the previous figures for context, a flow chart of a wireless communication method 2300 according to an example of the technology disclosed herein is shown. In such a method 2300, blocks 2010, 2020, and 2030 are as combined Figure 20 In such method 2300, UE 184 receives a third phase tracking reference signal (PTRS) from base station 180 on each of a plurality of beams not currently being used for downlink data transfer to UE 184 after the first transmission and before a second reception, wherein the second reception is based on the received PTRS (block 2370). In some examples, base station 180 uses the PTRS transmitted on each of the plurality of beams as a way to prepare UE 184 to use the currently unused beams for both sweeping and data transfer upon detecting a trigger.

[0159] Refer again Figure 25 , the UE sweep component 142' includes a third receiving component 142g'. In some examples, the third receiving component 142g' receives a phase tracking reference signal (PTRS) from the base station 180 on each of the multiple beams that are not currently used for downlink data transmission to the UE 184 after the first transmission and before the second reception, wherein the second reception is based on the received PTRS. Accordingly, the third receiving component 142g' may provide a means for receiving a phase tracking reference signal (PTRS) from the base station 180 on each of the multiple beams that are not currently used for downlink data transmission to the UE 184 after the first transmission and before the second reception, wherein the second reception is based on the received PTRS.

[0160] Reference Figure 24 , and continuing with the previous figures for context, a flow chart of a wireless communication method 2400 according to an example of the technology disclosed herein is shown. In such a method 2400, blocks 2010, 2020, and 2030 are as combined Figure 201414f. The method 2400 is performed as described. In such method 2400, UE 184 successfully decodes at least one of the second received beams (box 2480). UE 184 then transmits an acknowledgment of the successful decoding to the base station for the third time on each successfully decoded beam (box 2490). In a second continued example, UE 184 retransmits PUSCH 1491e as PUSCH 1491g on beams 1413g and 1414g upon successfully receiving and decoding the swept signal on one or more beams of beams 1411f–1414f. Thereafter, and in the absence of other transmissions that are unsuccessfully received by base station 180, UE 184 continues to transmit an acknowledgment of the successful decoding to the base station on each successfully decoded beam in subsequent cycles. In a second continued example, UE 184 transmits PUSCH 1491h on beams 1413h and 1414h in the next cycle.

[0161] Refer again Figure 25 , the UE sweep component 142' includes a decoding component 142h'. In some examples, the decoding component 142h' decodes at least one beam in the second received beam. Accordingly, the decoding component 142h' can provide a means for decoding at least one beam in the second received beam.

[0162] It should be understood that the specific order or hierarchy of the blocks in the disclosed process / flowcharts is an illustration of an example approach. It should be understood that the specific order or hierarchy of the blocks in these process / flowcharts can be rearranged based on design preferences. In addition, some blocks can be combined or omitted. The accompanying method claims present the elements of the various blocks in an example order and are not meant to be limited to the specific order or hierarchy presented.

[0163] The following examples are merely illustrative, and aspects thereof may be combined with aspects of other embodiments or teachings described herein without limitation.

[0164] Example 1 is a method of wireless communication, comprising: receiving, by a user equipment (UE) of a wireless communication network, conditions for sweeping a beam between a base station of the network and the UE; the conditions including beam sweeping trigger rules and a beam measurement configuration for measuring at least one characteristic of each beam on a downlink; measuring, by the UE, at least one characteristic of each beam according to the measurement configuration; detecting a trigger according to the trigger rules after the measurement; and sweeping the beam on an uplink by the UE based on the measurement in response to detecting the trigger.

[0165] In Example 2, the method of Example 1 further includes: wherein the triggering rule includes: detecting K consecutive unsuccessful receptions by the UE of downlink transmissions on the physical channel carried on the beam. In Example 3, the method of Example 1 or Example 2 further includes: the conditions include: a beam sweeping enable / disable flag, and a beam sweeping origin flag, the beam sweeping origin flag indicating the UE or base station as the origin of the sweep; and the sweeping is performed only when the beam sweeping enable / disable flag indicates that the beam sweeping is enabled and the beam sweeping origin flag indicates the UE as the origin of the sweep. In Example 4, the method of any one of Examples 1-3 further includes: the conditions include a time period during which the measurement remains valid; and the sweeping is performed only during the time period during which the measurement remains valid. In Example 5, the method of any one of Examples 1-4 further includes: the conditions include an order for sweeping within the beam; and the sweeping is performed within the beam in that order. In Example 6, the method of any one of Examples 1-5 further includes: the conditions include the number of beams to be swept; and the sweeping is performed among the number of beams in the order. In Example 7, the method of any one of Examples 1-6 further includes: the conditions are included in an information element in one of a radio resource control (RRC) message, a media access control-control element (MAC-CE) message, and a downlink control information (DCI) message. In Example 8, the method of any one of Examples 1-7 further includes: the conditions are included in an information element in an RRC message of one of the following types: RRC setup, RRC reconfiguration, RRC recovery, and system information block. In Example 9, the method of any one of Examples 1-8 further includes: transmitting, by the UE, at least one measured characteristic of each beam to the base station; receiving, by the UE, a second acknowledgment of successfully receiving, from the base station, the at least one measured characteristic of each transmitted beam; and receiving, by the UE, a third acknowledgment of successfully receiving, by the UE, a phase tracking reference signal from the base station on at least one reported beam after the second reception. In Example 10, the method of any one of Examples 1-9 further includes: requesting, by the UE, a condition for sweeping a beam of a physical channel between a base station of a network and the UE prior to receiving the condition; and wherein the receiving is in response to the request. In Example 11, the method of any one of Examples 1-10 further includes: wherein each swept beam carries a physical uplink control channel (PUCCH) of the UE, the PUCCH including an information element related to the detected trigger; and the method further includes: fourthly receiving, by the UE, data on one or more physical downlink shared channels (PDSCHs) via one or more beams corresponding to the beams on which the base station successfully received the information element.

[0166] In Example 12, a method of wireless communication includes: sending, by a base station of a wireless communication network, conditions for sweeping a beam between the UE and the base station to a UE of the network, the conditions including: a beam sweeping trigger rule and a beam measurement configuration for measuring at least one characteristic of each beam on a downlink; transmitting, by the base station, a reference signal on a beam on a downlink after the sending; first receiving, by the base station, a downlink beam measurement according to the beam measurement configuration from the UE in response to the sending and the sending; preparing, by the base station, at least one beam that is currently unused in the downlink in response to the receiving; second receiving, by the base station, on at least one prepared beam swept by the UE, an indication that a trigger has been detected at the UE according to the trigger rule; and second transmitting, by the base station, at least one physical channel to the UE on at least one prepared beam.

[0167] In Example 13, the method of Example 12 further includes: wherein the triggering rule includes: detecting K consecutive unsuccessful receptions by the UE of downlink transmissions on a physical channel carried on the beam. In Example 14, the method of any of Examples 12-13 further includes: wherein: the conditions further include: a beam sweep enable / disable flag, and a beam sweep origin flag, the beam sweep origin flag indicating the UE or base station as the origin of the sweep; wherein the preparation is performed only when the beam sweep enable / disable flag indicates that beam sweeping is enabled and the beam sweep origin flag indicates the UE as the origin of the sweep. In Example 15, the method of any of Examples 12-14 further includes: wherein the conditions further include a time period during which the measurement remains valid; and the preparation is performed only in response to receiving a measurement from the time period during which the measurement remains valid. In Example 16, the method of any of Examples 12-15 further includes: wherein the conditions further include an order for sweeping among the beams; and the preparation is performed only in response to receiving a measurement among the beams in that order. In Example 17, the method of any one of Examples 12-16 further includes wherein: the conditions further include the number of beams to be swept; and the preparation is performed only in response to receiving measurements in order among the number of beams. In Example 18, the method of any one of Examples 12-17 further includes: wherein the conditions are included in an information element in one of a radio resource control (RRC) message, a medium access control-control element (MAC-CE) message, and a downlink control information (DCI) message. In Example 19, the method of any one of Examples 12-18 further includes: wherein the conditions are included in an information element in an RRC message of one of the following types: RRC setup, RRC reconfiguration, RRC recovery, and system information block. In Example 20, the method of any one of Examples 12-19 further includes: receiving a request for a condition for sweeping a beam of a physical channel between a base station of a network and the UE from a third party before sending the condition; and wherein the sending is in response to the request. In Example 21, the method of any one of Examples 12-20 further includes: wherein each second received beam carries a physical uplink control channel (PUCCH) of the UE, the PUCCH including an information element related to a trigger detected according to a sweep trigger rule; and the method further includes: the base station transmits data for a third time on one or more physical downlink shared channels (PDSCH) via one or more beams corresponding to the beam on which the base station successfully received the information element.

[0168] In Example 22, a method of wireless communication includes: transmitting a beam sweeping configuration of a specified reference signal from a base station of a wireless communication network to a user equipment (UE) of the network; measuring, by the base station, at least one characteristic of each of a plurality of beams of a physical channel from the UE to the base station on an uplink, and each beam including the specified reference signal, the beams including each beam currently used for communication between the base station and the UE and a plurality of beams not currently used for downlink data transmission to the UE; detecting, by the base station, a beam sweeping trigger condition after the measurement; and sweeping, by the base station in response to the detection, a plurality of measured beams on a downlink to the UE based on the measurement and the configuration.

[0169] In Example 23, the method of Example 22 further includes: wherein the reference signal is a sounding reference signal (SRS). In Example 24, the method of any one of Examples 22-23 further includes: receiving, by the base station, confirmation from the UE that the UE is configured according to the transmitted beam sweeping configuration before the measurement; and wherein the measurement is performed only upon receipt of the confirmation. In Example 25, the method of any one of Examples 22-24 further includes: wherein the beam sweeping configuration includes a beam sweep enable / disable indicator that is set to enabled. In Example 26, the method of any one of Examples 22-25 further includes: preparing, after the measurement, a plurality of currently unused beams for sweeping upon detection of a beam sweeping trigger condition. In Example 27, the method of any one of Examples 22-26 further includes: wherein the preparation includes: transmitting, by the base station, a second phase tracking reference signal (PTRS) on each of a plurality of beams that are not currently used for downlink data transmission to the UE. In Example 28, the method of any one of Examples 22-27 further includes: after the sweeping, receiving from the UE a second acknowledgment of a successful transmission on each of the plurality of swept beams; and thirdly transmitting data to the UE on the plurality of acknowledged beams. In Example 29, the method of any one of Examples 22-28 further includes: wherein the detecting includes: determining, over K consecutive communication cycles between the base station and the UE, that the UE has not successfully received the K consecutive cycles of DL transmissions.

[0170] In Example 30, the method includes: receiving, by a user equipment (UE) of a wireless communication network, a beam sweeping configuration of a specified reference signal from a base station of the network; first transmitting, by the UE, the specified reference signal to the base station on each of a plurality of beams of a physical channel, including each beam currently used for data transfer between the base station and the UE and a plurality of beams not currently used for data transfer from the base station to the UE; and second receiving, by the UE based on measurement and configuration, the plurality of transmitted beams swept on a downlink to the UE for downlink data transfer from the base station to the UE.

[0171] In Example 31, the method of Example 30 includes: determining, by the UE, that a subset of the second received beams successfully transmits data from the base station to the UE; and confirming, by the UE, to the base station, the successful transmission of data from the base station to the UE on the subset of received beams. In Example 32, the method of any one of Examples 30-31 includes: wherein the reference signal is a sounding reference signal (SRS). In Example 33, the method of any one of Examples 31-32 includes: transmitting, by the UE, to the base station, a second confirmation that the UE is configured according to the received beam sweep configuration, before the first transmission. In Example 34, the method of any one of Examples 31-33 includes: wherein the beam sweep configuration includes a beam sweep enable / disable indicator that is set to enabled. In Example 35, the method of any one of Examples 31-34 includes: receiving, by the UE, a third phase tracking reference signal (PTRS) from the base station on each of a plurality of beams that is not currently used for downlink data transmission to the UE after the first transmission and before the second reception, wherein the second reception is based on the received PTRS. In Example 36, the method of any one of Examples 31-35 includes: successfully decoding, by the UE, at least one of the second received beams; and thirdly transmitting, by the UE, an acknowledgment of the successful decoding to the base station on each successfully decoded beam.

[0172] Example 37 includes an apparatus for wireless communication, comprising: a memory; and at least one processor coupled to the memory and configured to perform the method of any one or more of claims 1-36.

[0173] Example 38 includes a computer-readable medium storing computer-executable code that, when executed by a processor, causes the processor to perform the method of any one or more of claims 1-36.

[0174] Example 39 includes an apparatus for wireless communication, comprising: means for receiving, by a user equipment (UE) of a wireless communication network, conditions for sweeping a beam between a base station of the network and the UE; the conditions comprising beam sweeping trigger rules and a beam measurement configuration for measuring at least one characteristic of each beam on a downlink; means for measuring, by the UE, at least one characteristic of each beam according to the measurement configuration; means for detecting, by the UE after the measurement, a trigger according to the trigger rules; and means for sweeping, by the UE, a beam on an uplink based on the measurement in response to detecting the trigger.

[0175] In Example 40, the apparatus of Example 39 includes: wherein the triggering rule includes: detecting K consecutive unsuccessful receptions by the UE of downlink transmissions on a physical channel carried on the beam. In Example 41, the apparatus of any one of Examples 39-40 includes: wherein: the conditions further include: a beam sweeping enable / disable flag, and a beam sweeping origin flag, the beam sweeping origin flag indicating the UE or base station as the origin of the sweep; and the sweeping is performed only when the beam sweeping enable / disable flag indicates that beam sweeping is enabled and the beam sweeping origin flag indicates the UE as the origin of the sweep. In Example 42, the apparatus of any one of Examples 39-41 includes: wherein: the conditions further include a time period during which the measurement remains valid; and the sweeping is performed only during the time period during which the measurement remains valid. In Example 43, the apparatus of any one of Examples 39-42 includes: wherein: the conditions further include an order for sweeping within the beam; and the sweeping is performed within the beam in that order. In Example 44, the apparatus of any one of Examples 39-43 includes wherein: the conditions further include a number of beams to be swept; and the sweeping is performed among the number of beams in the order. In Example 45, the apparatus of any one of Examples 39-44 includes wherein: the conditions are included in an information element in one of a radio resource control (RRC) message, a medium access control-control element (MAC-CE) message, and a downlink control information (DCI) message. In Example 46, the apparatus of any one of Examples 39-45 includes wherein: the conditions are included in an information element in an RRC message of one of the following types: RRC setup, RRC reconfiguration, RRC recovery, and system information block. In Example 47, the apparatus of any one of Examples 39-46 includes: means for transmitting, by the UE, at least one measured characteristic of each beam to the base station; means for secondly receiving, by the UE from the base station, an acknowledgment of successfully receiving, by the UE, at least one measured characteristic of each transmitted beam; and means for thirdly receiving, by the UE, a phase tracking reference signal from the base station on at least one reported beam after the second reception. In Example 48, the apparatus of any one of Examples 39-47 includes: means for requesting, by the UE, conditions for beams sweeping a physical channel between a base station of a network and the UE prior to receiving the conditions; and wherein the receiving is in response to the request. In Example 49, the apparatus of any one of Examples 39-48 includes: wherein each swept beam carries a physical uplink control channel (PUCCH) of the UE, the PUCCH including an information element related to the detected trigger; and the apparatus further includes: means for fourthly receiving, by the UE, data on one or more physical downlink shared channels (PDSCHs) via one or more beams corresponding to the beam on which the base station successfully received the information element.

[0176] Example 50 includes an apparatus for wireless communication, comprising: means for transmitting, by a base station of a wireless communication network, to a UE of the network, conditions for sweeping a beam between the UE and the base station, the conditions comprising: beam sweep triggering rules, and a beam measurement configuration for measuring at least one characteristic of each beam on a downlink. Example 50 further includes: means for transmitting, by the base station, a reference signal on a beam on a downlink after the transmitting; means for receiving, by the base station, downlink beam measurements according to the beam measurement configuration from the UE in response to the transmitting and the transmitting; means for preparing, by the base station, at least one beam currently unused in the downlink in response to the receiving; means for secondly receiving, by the base station, an indication on at least one prepared beam swept by the UE that a trigger has been detected at the UE in accordance with the triggering rules; and means for secondly transmitting, by the base station, at least one physical channel to the UE on at least one prepared beam.

[0177] In Example 51, in the apparatus of Example 50, the triggering rule includes: detecting K consecutive unsuccessful receptions by the UE of downlink transmissions on a physical channel carried on the beam. In Example 52, in the apparatus of any one of Examples 50-51, the conditions further include: a beam sweeping enable / disable flag, and a beam sweeping origin flag, the beam sweeping origin flag indicating the UE or base station as the origin of the sweep. In such examples, the preparation is performed only when the beam sweeping enable / disable flag indicates that beam sweeping is enabled and the beam sweeping origin flag indicates the UE as the origin of the sweep. In Example 53, in the apparatus of any one of Examples 50-52, the conditions further include a time period during which the measurement remains valid; and the preparation is performed only in response to receiving a measurement from the time period during which the measurement remains valid. In Example 54, in the apparatus of any one of Examples 50-53, the conditions further include an order for sweeping among the beams; and the preparation is performed only in response to receiving a measurement among the beams in that order. In Example 55, in the apparatus of any one of Examples 50-54, the conditions further include the number of beams to be swept; and the preparation is performed only in response to receiving a measurement among the number of beams in the order. In Example 56, in the apparatus of any one of Examples 50-55, the conditions are included in an information element in one of a radio resource control (RRC) message, a medium access control-control element (MAC-CE) message, and a downlink control information (DCI) message. In Example 57, in the apparatus of any one of Examples 50-56, the conditions are included in an information element in an RRC message of one of the following types: RRC setup, RRC reconfiguration, RRC recovery, and system information block. In Example 58, the apparatus of any one of Examples 50-57 further includes: a device for receiving a request for a condition for sweeping a beam of a physical channel between a base station of a network and the UE from a third party before sending the condition. In such examples, the sending is in response to the request. In Example 59, in the apparatus of any of Examples 50-58, each second received beam carries a physical uplink control channel (PUCCH) of the UE, the PUCCH including an information element related to a trigger detected according to the sweep trigger rule. Such examples further include means for thirdly transmitting, by the base station, data on one or more physical downlink shared channels (PDSCHs) via one or more beams corresponding to the beam on which the base station successfully received the information element.

[0178] Example 60 includes an apparatus for wireless communication, comprising: a device for transmitting a beam sweeping configuration of a specified reference signal from a base station of a wireless communication network to a user equipment (UE) of the network; a device for measuring, by the base station, at least one characteristic of each of a plurality of beams of a physical channel from the UE to the base station on an uplink, and each beam includes the specified reference signal, the beams including each beam currently used for communication between the base station and the UE and a plurality of beams not currently used for downlink data transmission to the UE; a device for detecting, by the base station, a beam sweeping trigger condition after the measurement; and a device for sweeping, by the base station, a plurality of measured beams on a downlink to the UE based on the measurement and configuration in response to the detection.

[0179] In Example 61, in the apparatus of Example 60, the reference signal is a sounding reference signal (SRS). In Example 62, any of Examples 60-61 further includes: a device for receiving, by the base station, from the UE, a confirmation that the UE is configured according to the transmitted beam sweeping configuration before the measurement. In such examples, the measurement is performed only upon receipt of the confirmation. In Example 63, in the apparatus of any of Examples 60-62, the beam sweeping configuration includes a beam sweep enable / disable indicator that is set to enabled. In Example 64, any of Examples 60-63 further includes: a device for preparing, after the measurement, a plurality of currently unused beams for sweeping when a beam sweep trigger condition is detected. In Example 65, in the apparatus of any of Examples 60-64, the preparation includes: a second transmission by the base station of a phase tracking reference signal (PTRS) on each of a plurality of beams that are not currently used for downlink data transmission to the UE. In Example 66, any of Examples 60-65 further includes: means for receiving, after the sweeping, from the UE an acknowledgment of a successful transmission on each of the plurality of swept beams; and means for transmitting data to the UE a third time on the plurality of acknowledged beams. In Example 67, in the apparatus of any of Examples 60-66, the detecting includes: determining, over K consecutive communication cycles between the base station and the UE, that the UE has not successfully received the K consecutive cycles of DL transmissions.

[0180] Example 68 includes an apparatus for wireless communication, comprising: a device for receiving, by a user equipment (UE) of a wireless communication network, a beam sweeping configuration for a specified reference signal from a base station of the network; a device for transmitting, by the UE, the specified reference signal to the base station on each of a plurality of beams of a physical channel, including each beam currently used for data transfer between the base station and the UE and a plurality of beams not currently used for data transfer from the base station to the UE; and a device for secondly receiving, by the UE based on measurement and configuration, the plurality of transmitted beams swept on a downlink to the UE for downlink data transfer from the base station to the UE.

[0181] In Example 69, Example 68 further includes: means for determining, by the UE, that a subset of the second received beams successfully delivered data from the base station to the UE; and means for confirming, by the UE, to the base station, the successful delivery of data from the base station to the UE on the subset of received beams. In Example 70, in the apparatus of any one of Examples 68-69, the reference signal is a sounding reference signal (SRS). In Example 71, any one of Examples 68-70 further includes: means for transmitting, by the UE, to the base station, a second confirmation of configuring the UE according to the received beam sweeping configuration prior to the first transmission. In Example 72, in the apparatus of any one of Examples 68-71, the beam sweeping configuration includes a beam sweep enable / disable indicator that is set to enabled. In Example 73, any of Examples 68-72 further includes: means for receiving, by the UE, a third phase tracking reference signal (PTRS) from the base station on each of the plurality of beams not currently used for downlink data delivery to the UE after the first transmission and before the second reception, wherein the second reception is based on the received PTRS. In Example 74, any of Examples 68-73 further includes: means for successfully decoding, by the UE, at least one of the second received beams; and means for thirdly transmitting, by the UE, an acknowledgment of the successful decoding to the base station on each successfully decoded beam.

[0182] The preceding description is provided to enable any person skilled in the art to practice the various aspects described herein. Various modifications to these aspects will be readily apparent to those skilled in the art, and the universal principles defined herein may be applied to other aspects. Thus, the claims are not intended to be limited to the aspects shown herein, but rather should be granted the full scope consistent with the language of the claims, wherein singular references to elements are not intended to mean "one and only one," but rather "one or more," unless otherwise specified. The term "exemplary" is used herein to mean "serving as an example, instance, or illustration." Any aspect described herein as "exemplary" is not necessarily to be construed as superior to or superior to other aspects. Unless otherwise specifically stated, the term "some" refers to one or more. Combinations such as "at least one of A, B, or C," "one or more of A, B, or C," "at least one of A, B, and C," "one or more of A, B, and C," and "A, B, C, or any combination thereof" include any combination of A, B, and / or C, and may include multiple As, multiple Bs, or multiple Cs. Specifically, combinations such as "at least one of A, B, or C," "one or more of A, B, or C," "at least one of A, B, and C," "one or more of A, B, and C," and "A, B, C, or any combination thereof" may be A only, B only, C only, A and B, A and C, B and C, or A and B and C, wherein any such combination may include one or more members of A, B, or C. All structural and functional equivalents of the various aspects described throughout this disclosure to those of ordinary skill in the art now or hereafter known are expressly incorporated herein by reference and are intended to be encompassed by the claims. In addition, nothing disclosed herein is intended to be dedicated to the public, regardless of whether such disclosure is expressly recited in the claims. The terms "module," "mechanism," "element," "device," etc. may not be a substitute for the term "means." As such, no claim element should be construed as means-plus-function unless the element is expressly recited using the phrase "means for."

Claims

1. A method of wireless communication, comprising: Conditions for sweeping a beam between a network entity of a wireless communication network and a user equipment (UE) of the network are received, the conditions comprising: Beam sweep triggering rules, a beam measurement configuration for measuring, on a downlink, at least one characteristic of each of said beams, Beam sweep enable / disable flag, and a beam sweep origin flag, where the beam sweep origin flag indicates the UE or the network entity as an origin of the sweep; measuring, by the UE, at least one characteristic of each of the beams according to the measurement configuration; detecting, by the UE after the measurement, a trigger according to the triggering rule; and In response to detecting the trigger, the beam is swept on an uplink by the UE based on the measurement and only when the beam sweeping enable / disable flag indicates that beam sweeping is enabled and the beam sweep origin flag indicates the UE as the origin of the sweep.

2. The method according to claim 1, wherein The triggering rule includes: detecting K consecutive unsuccessful receptions by the UE of downlink transmissions on the physical channel carried on the beam.

3. The method of claim 1, wherein: The conditions further include a time period for which the measurement remains valid; and The sweep is performed only during the time period during which the measurement remains valid.

4. The method of claim 1, wherein: The conditions further include an order for sweeping among the beams and a number of beams to sweep; and The sweeping is performed among the number of beams in the order.

5. The method according to claim 1, wherein The condition is contained in an information element in one of: an RRC (Radio Resource Control) setup, RRC reconfiguration, RRC recovery and a system information block RRC message; a Medium Access Control - Control Element (MAC-CE) message; and a Downlink Control Information (DCI) message.

6. The method of claim 1, further comprising: transmitting, by the UE to the network entity, the measured at least one characteristic of each of the beams; secondly receiving, by the UE from the network entity, an acknowledgment of successful receipt of the measured at least one characteristic of each of the transmitted beams; as well as A phase tracking reference signal is thirdly received by the UE from the network entity on at least one of the measured beams after the second reception.

7. The method according to claim 1: Further including: requesting, by the UE, a condition for a beam sweeping a physical channel between the network entity of the network and the UE before receiving the condition; The receiving is in response to the request.

8. The method according to claim 1: wherein each swept beam carries a physical uplink control channel (PUCCH) of the UE, the PUCCH including an information element related to the detected trigger; and The method further comprises: Data is fourthly received by the UE on one or more physical downlink shared channels (PDSCHs) via one or more beams corresponding to the beam on which the network entity successfully received the information element.

9. An apparatus for wireless communication, comprising: Memory; as well as at least one processor coupled to the memory, the memory comprising instructions executable by the at least one processor to cause the apparatus to: A condition for sweeping a beam between a network entity of a wireless communication network and the device is received by the device of the network, the condition comprising: Beam sweep triggering rules, a beam measurement configuration for measuring, on a downlink, at least one characteristic of each of said beams, Beam sweep enable / disable flag, and a beam sweep origin flag, the beam sweep origin flag indicating the device or the network entity as an origin of a sweep; measuring, by the apparatus according to the measurement configuration, at least one characteristic of each of the beams; detecting a trigger by the device according to the trigger rule after the measurement; and The beam is swept on an uplink by the device in response to detecting the trigger based on the measurement and only when the beam sweep enable / disable flag indicates that beam sweeping is enabled and the beam sweep origin flag indicates the device as the origin of the sweep.

10. The device according to claim 9, wherein The triggering rule includes detecting K consecutive unsuccessful receptions by the device of downlink transmissions on the physical channel carried on the beam.

11. The apparatus of claim 9, wherein: The conditions further include a time period for which the measurement remains valid; and The sweep is performed only during the time period during which the measurement remains valid.

12. The apparatus of claim 9, wherein: The conditions further include an order for sweeping among the beams and a number of beams to sweep; and The sweeping is performed among the number of beams in the order.

13. The apparatus of claim 9, wherein: The condition is contained in an information element in one of: an RRC (Radio Resource Control) setup, RRC reconfiguration, RRC recovery and a system information block RRC message; a Medium Access Control - Control Element (MAC-CE) message; and a Downlink Control Information (DCI) message.

14. A non-transitory computer-readable medium storing computer-executable code, which, when executed by a processor, causes the processor to: Conditions for sweeping a beam between a network entity of a wireless communication network and a user equipment (UE) of the network are received, the conditions comprising: Beam sweep triggering rules, a beam measurement configuration for measuring, on a downlink, at least one characteristic of each of said beams, Beam sweep enable / disable flag, and a beam sweep origin flag, where the beam sweep origin flag indicates the UE or the network entity as an origin of the sweep; measuring, by the UE according to the measurement configuration, at least one characteristic of each of the beams; After the measurement, the UE detects a trigger according to the trigger rule; as well as In response to detecting the trigger, the beam is swept on an uplink by the UE based on the measurement and only when the beam sweeping enable / disable flag indicates that beam sweeping is enabled and the beam sweep origin flag indicates the UE as the origin of the sweep.

15. The non-transitory computer readable medium of claim 14, wherein: The triggering rule includes: detecting K consecutive unsuccessful receptions by the UE of downlink transmissions on the physical channel carried on the beam.

16. The non-transitory computer readable medium of claim 14, wherein: The code, when executed by a processor, further causes the processor to: transmitting, by the UE to the network entity, the measured at least one characteristic of each of the beams; secondly receiving, by the UE from the network entity, an acknowledgment of successful receipt of the measured at least one characteristic of each of the transmitted beams; as well as A phase tracking reference signal is thirdly received by the UE from the network entity on at least one of the measured beams after the second reception.

17. The non-transitory computer-readable medium of claim 14: wherein the code, when executed by a processor, further causes the processor to: request, by the UE, a condition for sweeping a beam of a physical channel between the network entity of the network and the UE before receiving the condition; The receiving is in response to the request.

18. The non-transitory computer-readable medium of claim 14: wherein each swept beam carries a physical uplink control channel (PUCCH) of the UE, the PUCCH including an information element related to the detected trigger; and When executed by the processor, the code further causes the processor to: fourthly receive data by the UE on one or more physical downlink shared channels (PDSCHs) via one or more beams corresponding to the beam on which the network entity successfully received the information element.

19. A device for wireless communication, comprising: Means for receiving, by the device of a wireless communication network, a condition for sweeping a beam between a network entity of the network and the device, the condition comprising: Beam sweep triggering rules, a beam measurement configuration for measuring, on a downlink, at least one characteristic of each of said beams, Beam sweep enable / disable flag, and a beam sweep origin flag, the beam sweep origin flag indicating the device or the network entity as an origin of a sweep; means for measuring, by the device, at least one characteristic of each of the beams according to the measurement configuration; means for detecting a trigger by said device according to said triggering rules after said measuring; and Means for sweeping the beam on an uplink by the device based on the measurement and only when the beam sweep enable / disable flag indicates that beam sweeping is enabled and the beam sweep origin flag indicates the device as the origin of the sweep, in response to detecting the trigger.

20. The apparatus of claim 19, wherein: The triggering rule includes detecting K consecutive unsuccessful receptions by the device of downlink transmissions on the physical channel carried on the beam.

21. The apparatus of claim 19, wherein: The conditions further include a time period for which the measurement remains valid; and The sweep is performed only during the time period during which the measurement remains valid.

22. The apparatus of claim 19, wherein: The conditions further include an order for sweeping among the beams and a number of beams to sweep; and The sweeping is performed among the number of beams in the order.

23. The apparatus of claim 19, wherein: The condition is contained in an information element in one of: an RRC (Radio Resource Control) setup, RRC reconfiguration, RRC recovery and a system information block RRC message; a Medium Access Control - Control Element (MAC-CE) message; and a Downlink Control Information (DCI) message.

24. The apparatus of claim 19, further comprising: means for transmitting, by the apparatus to the network entity, the measured at least one characteristic of each of the beams; means for secondly receiving, by the device from the network entity, an acknowledgment of successful receipt of the measured at least one characteristic of each of the transmitted beams; as well as Means for thirdly receiving, by the apparatus, a phase tracking reference signal from the network entity on at least one of the measured beams after the second receiving.

25. The apparatus of claim 19: Further including: means for requesting, by the device, conditions for sweeping a beam of a physical channel between the network entity of the network and the device prior to receiving the conditions; The receiving is in response to the request.

26. The apparatus of claim 19: wherein each swept beam carries a physical uplink control channel (PUCCH) of the device, the PUCCH comprising an information element related to the detected trigger; and The device further comprises: Means for fourthly receiving, by the apparatus, data on one or more physical downlink shared channels (PDSCHs) via one or more beams corresponding to the beam on which the network entity successfully received the information element.

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