Coverage enhancement for beam change confirmation

Abstract

Certain aspects of the present disclosure provide techniques for enhancing coverage while sending an acknowledgement (ACK) to a base station to confirm a beam change instruction. Such aspects of the present disclosure can increase the reliability of control information sent by a user equipment (UE) on a control channel, such as ACK feedback sent by the UE to the base station on a physical uplink control channel. In certain aspects, the UE can receive information from the base station that indicates a beam switch from a first beam to a second beam, where the UE communicates with the base station via the first beam. Based on the information indicating the beam switch, the UE can also send two or more ACK messages to the base station on the control channel, and the two or more ACK messages can confirm receipt of the information indicating the beam switch from the base station.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims the benefit of U.S. Provisional Application Serial No. 62 / 948,182, filed on December 13, 2019, entitled “COVERAGE ENHANCEMENT FOR A BEAM CHANGE ACKNOWLEDGEMENT,” and U.S. Patent Application No. 17 / 116,965, filed on December 9, 2020, entitled “COVERAGE ENHANCEMENT FOR A BEAM CHANGE ACKNOWLEDGEMENT,” the entire contents of which are expressly incorporated herein by reference. Technical Field

[0003] The present disclosure relates generally to communication systems, and more particularly, to beam changing in wireless communications between a user equipment (UE) and a base station. Background Art

[0004] Wireless communication systems are widely deployed to provide a variety of telecommunication services, such as telephony, video, data, messaging, and broadcasting. Typical wireless communication systems may employ multiple access technologies capable of supporting 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.

[0005] 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, regional, 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 3rd 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. Further improvements to 5G NR technology are needed. These improvements also apply to other multiple access technologies and telecommunication standards that adopt these technologies. Summary of the Invention

[0006] The following presents a simplified summary of one or more aspects in order to provide a basic understanding of such aspects. This summary is not an extensive overview of all contemplated aspects and is neither intended to identify key or critical elements of all aspects nor to delineate 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.

[0007] In some radio access networks (RANs), base stations and user equipment (UEs) can communicate in millimeter wave (mmW) spectrum (e.g., in some aspects, the mmW spectrum can include some near-mmW spectrum). Accordingly, the base stations and UEs can beamform transmissions, which can mitigate higher path losses at higher frequencies, e.g., relative to omnidirectional transmissions and / or transmissions in sub-six gigahertz (GHz) and / or sub-seven gigahertz frequency bands.

[0008] Using beamforming technology, the base station can select one of the beam sets pointing in different directions to communicate the selected beam. After the selection of the beam, the best beam can be changed, and the base station can therefore determine to change from the current beam to another beam. During the beam change process, the base station can send a beam change instruction to the user equipment (UE) to indicate that the base station intends to change from the current beam to another beam. The base station can ensure that the UE has correctly received the beam change instruction and can switch the beam after receiving an acknowledgment (ACK) feedback confirming the receipt of the beam change instruction from the UE. The UE can receive the beam change instruction from the base station and send an acknowledgment to the base station.

[0009] Potentially, the base station may not be able to successfully receive some transmissions from the UE due to, for example, higher path loss in mmW communications and / or other factors affecting the channel over which the UE beamforms such transmissions. For example, the base station may not be able to receive ACK feedback from the UE when the signal path is blocked (e.g., the beam via which the UE sends ACK feedback may be blocked), insufficient transmission power, and / or other reason(s).

[0010] The UE may send some control information, such as ACK feedback, to the base station on an uplink control channel, such as a physical uplink control channel (PUCCH). When the base station cannot receive the UE transmission on the uplink control channel (e.g., because the beam via which the UE transmits on the control channel is blocked, insufficient transmission power is configured for uplink control channel transmission, etc.), the base station may not receive ACK feedback from the UE confirming the UE's receipt of the beam change instruction.

[0011] In response to a beam change instruction, a base station's failure to successfully receive ACK feedback from a UE may result in the beam becoming misaligned, timing synchronization lost, radio link failure, and / or other potentially undesirable consequences. Therefore, there is a need to address unsuccessful transmissions on control channels beamformed by UEs.

[0012] This disclosure describes various techniques and solutions for increasing the reliability of UE transmissions on control channels, such as PUCCH. Specifically, this disclosure describes some systems, methods, and apparatus for enhancing transmission coverage on control channels, including ACK feedback and other control information on PUCCH.

[0013] In one aspect of the present disclosure, a method, a computer-readable medium, and an apparatus are provided. The apparatus may be a user equipment (UE) or a component thereof. The apparatus may receive information from a base station indicating a beam switch from a first beam via which the apparatus communicates with the base station to a second beam. Based on the information indicating the beam switch, the apparatus may also send two or more ACK messages to the base station on a control channel. The two or more ACK messages may confirm receipt of the information indicating the beam switch from the base station.

[0014] In one aspect of the present disclosure, a method, computer-readable medium, and apparatus are provided. The apparatus may be a base station or a component thereof. The apparatus may transmit information to a UE indicating a beam switch from a first beam via which the apparatus communicates with the UE to a second beam. In response to the transmitted information indicating the beam switch, the apparatus may also receive two or more ACK messages from the base station on a control channel from the UE. The two or more ACK messages may confirm receipt of the information indicating the beam switch from the apparatus.

[0015] 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 the accompanying drawings set forth in detail certain illustrative features of 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 include all such aspects and their equivalents. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 is a diagram illustrating an example of a wireless communication system and an access network.

[0017] Figure 2A 、 Figure 2B 、 Figure 2C and Figure 2D 5G / NR frame, DL channels within a 5G / NR subframe, and UL channels within a second 5G / NR frame and 5G / NR subframe, respectively.

[0018] Figure 3 is a diagram illustrating an example of a base station and a user equipment (UE) in an access network.

[0019] Figure 4 is a diagram illustrating a beam changing process according to certain aspects of the present disclosure.

[0020] Figure 5 is a call flow diagram of signaling between a UE and a base station according to certain aspects of the present disclosure.

[0021] Figure 6 is a flow chart of a wireless communication method.

[0022] Figure 7 is a conceptual data flow diagram illustrating the flow of data between different parts / components in an example apparatus.

[0023] Figure 8 is a diagram illustrating an example of a hardware implementation for an apparatus employing a processing system.

[0024] Figure 9 is a flow chart of a wireless communication method.

[0025] Figure 10 is a conceptual data flow diagram illustrating the flow of data between different parts / components in an example apparatus.

[0026] Figure 11 is a diagram illustrating an example of a hardware implementation for an apparatus employing a processing system.

[0027] Figure 12A 、 Figure 12B 、 Figure 12C and Figure 12D is a diagram illustrating an example of coverage enhancement used by a UE to send ACK. DETAILED DESCRIPTION

[0028] The detailed description set forth below in conjunction with the accompanying drawings is intended to serve as a description of various configurations and is not intended to represent the only configuration in which the concepts described herein can be practiced. The detailed description includes specific details for the purpose of providing a thorough understanding of the various concepts. However, it will be apparent to those skilled in the art that these concepts can be implemented without these specific details. In some cases, well-known structures and components are shown in block diagram form to avoid confusing such concepts.

[0029] Several aspects of telecommunication 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.

[0030] For example, any part of an element or an element or any combination of elements can be implemented as a "processing system" including one or more processors. Examples of processors include microprocessors, microcontrollers, graphics processing units (GPUs), central processing units (CPUs), application processors, digital signal processors (DSPs), reduced instruction set computing (RISC) processors, system-on-chip (SoCs), baseband processors, field programmable gate arrays (FPGAs), programmable logic devices (PLDs), state machines, gating logic, discrete hardware circuits, and other suitable hardware configured to perform the various functions described throughout this disclosure. One or more processors in a processing system can execute software. Software should be broadly interpreted as referring to instructions, instruction sets, codes, code segments, program codes, programs, subroutines, software components, applications, software applications, software packages, routines, subroutines, objects, executable programs, execution threads, processes, functions, etc., whether referring to software, firmware, middleware, microcode, hardware description languages, or other.

[0031] Thus, in one or more example embodiments, the functions described may be implemented in hardware, software, or any combination thereof. If implemented in software, the functions may be stored in or encoded as one or more instructions or codes in a computer-readable medium. Computer-readable media include computer storage media. A storage medium 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 above types of computer-readable media, or any other medium that can be used to store computer-executable code in the form of instructions or data structures accessible to a computer.

[0032] Figure 11 is a diagram illustrating an example of a wireless communication system and access network 100. The wireless communication system (also referred to as a wireless wide area network (WWAN)) includes a base station 102, a UE 104, an evolved packet core (EPC) 160, and other core networks 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.

[0033] Base stations 102 configured for 4G LTE (collectively referred to as Evolved Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access Network (E-UTRAN)) can interface with EPC 160 via a backhaul link 132 (e.g., an S1 interface). Base stations 102 configured for 5G NR (collectively referred to as Next Generation RAN (NG-RAN)) can interface with core network 190 via a backhaul link 184. Among other functions, base stations 102 can perform one or more of the following functions: transmission 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 device tracking, RAN information management (RIM), paging, positioning, and delivery of warning messages. Base stations 102 may communicate with each other via backhaul links 134 (eg, an X2 interface) directly or indirectly (eg, via EPC 160 or core network 190). Backhaul links 134 may be wired or wireless.

[0034] Base stations 102 can communicate wirelessly with UEs 104. Each base station 102 can provide communication coverage for its own geographic coverage area 110. There can 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 services to a restricted group called 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 use multiple-input multiple-output (MIMO) antenna technology, including spatial multiplexing, beamforming, and / or transmit diversity. The communication link can be over one or more carriers. The base station 102 / UE 104 can use spectrum of up to Y MHz (e.g., 5, 10, 15, 20, 100, 400, etc. MHz) bandwidth for each carrier allocated in a total carrier aggregation of Yx MHz (e.g., for x component carriers) for transmission on each. 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., DL may be allocated more or fewer carriers than UL). A component carrier 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 carrier may be referred to as a secondary cell (SCell).

[0035] Some UEs 104 can communicate with each other using device-to-device (D2D) communication links 158. The D2D communication links 158 can use the DL / UL WWAN spectrum. The D2D communication links 158 can use 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 can be achieved through various wireless D2D communication systems, such as FlashLinQ, WiMedia, Bluetooth, ZigBee, Wi-Fi based on the IEEE 802.11 standard, LTE, or NR.

[0036] The wireless communication system may also include a Wi-Fi access point (AP) 150 that communicates with a Wi-Fi station (STA) 152 in the 5 GHz unlicensed spectrum via a communication link 154. When communicating in the unlicensed spectrum, the STA 152 / AP 150 may perform a clear channel assessment (CCA) prior to communication to determine whether the channel is available.

[0037] The small cell 102' can operate in licensed and / or unlicensed spectrum. When operating in the unlicensed spectrum, the small cell 102' can employ NR and use the same 5 GHz unlicensed spectrum used by the Wi-Fi AP 150. The small cell 102' employing NR in the unlicensed spectrum can improve the coverage of the access network and / or increase the capacity of the access network.

[0038] Base station 102, whether a small cell 102' or a large cell (e.g., a macro base station), can include an eNB, a gNodeB (gNB), or another type of base station. Some base stations, such as gNB 180, can operate in the traditional sub-6 GHz spectrum, millimeter wave (mmW) frequencies, and / or near-mmW frequencies for communicating with UE 104. When gNB 180 operates in mmW or near-mmW frequencies, gNB 180 can be referred to as a mmW base station. Extremely high frequency (EHF) is a portion of the RF portion of the electromagnetic spectrum. EHF has a range of 30 GHz to 300 GHz, with wavelengths between 1 mm and 10 mm. Radio waves in this frequency band can be referred to as millimeter waves. Near-mmW can extend to frequencies of 3 GHz with wavelengths of 100 mm. The super high frequency (SHF) band extends between 3 GHz and 30 GHz and is also known as centimeter waves. Communications using the mmW / near-mmW radio frequency bands (e.g., 3 GHz–300 GHz) have extremely high path loss and short range. The mmW base station 180 may utilize beamforming 182 with the UE 104 to compensate for the extremely high path loss and short range.

[0039] Base station 180 may transmit beamformed signals in one or more transmit directions 182′ to UE 104. UE 104 may receive beamformed signals from base station 180 in one or more receive directions 182″. UE 104 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 may perform beam training to determine optimal receive and transmit directions for each of base station 180 / UE 104. The transmit direction and receive direction for base station 180 may be the same or different. The transmit direction and receive direction for UE 104 may be the same or different.

[0040] 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 communicate with a Home Subscriber Server (HSS) 174. MME 162 is a control node that handles signaling between UE 104 and EPC 160. Generally, MME 162 provides bearer and connection management. All user Internet Protocol (IP) packets are transmitted 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 may provide functionality for MBMS user service provisioning and delivery. The BM-SC 170 may serve as the entry point for content providers' MBMS transmissions, may be used to authorize and initiate MBMS bearer services within a public land mobile network (PLMN), and may be used to schedule MBMS transmissions. The MBMS Gateway 168 may be used to distribute MBMS services to base stations 102 belonging to a Multicast Broadcast Single Frequency Network (MBSFN) area broadcasting a specific service, and may be responsible for session management (start / stop) and collecting charging information related to eMBMS.

[0041] 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 communicate 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. Typically, the AMF 192 provides QoS flow and session management. All user Internet Protocol (IP) packets are transmitted 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.

[0042] A base station may also be referred to as a gNB, Node B, evolved Node B (eNB), access point, base transceiver station, radio base station, radio transceiver, transceiver functionality, basic service set (BSS), extended service set (ESS), transmit receive 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, a smart device, a wearable device, a vehicle, an electric meter, a gas pump, a large or small kitchen appliance, a medical 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, a toaster, 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.

[0043] Reference again Figure 1 In some aspects, the UE 104 may be configured to utilize coverage enhancement to send an ACK to the base station to confirm the beam changing instruction. For example, Figure 1 The UE 104 may include a coverage enhancement component 198, which is configured to determine to send an acknowledgement (ACK) on a physical uplink control channel (PUCCH) with coverage enhancement to confirm the transmission beam change of the base station. The UE 104 may receive a downlink signal from a base station (e.g., 102 / 180). The UE 104 may determine that the downlink signal includes a beam switching signal, which indicates that the base station will change the transmission beam used for downlink communication with the UE 104. Based on the determination that the DL signal includes the beam switching signal, the UE may determine to send an ACK in the PUCCH with coverage enhancement to confirm the transmission beam change of the base station. The UE 104 may send an ACK to the base station in the PUCCH with coverage enhancement.

[0044] Reference again Figure 1 In certain aspects, the base station 102 / 180 may be configured to receive an ACK from the UE confirming receipt of the beam switching signal, wherein the ACK is received using coverage enhancement. For example, Figure 1The base station 102 / 180 may include a beam switching component 199 configured to generate a downlink signal including a beam switching signal indicating that the base station 102 / 180 will change its downlink transmit beam. The base station 102 / 180 may transmit a downlink signal including the beam switching signal to the UE, indicating that the base station will change the transmit beam used for downlink communication with the UE 104. The base station 102 / 180 may receive an ACK from the UE confirming receipt of the base station's transmit beam change.

[0045] 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.

[0046] Figure 2A FIG200 is a diagram illustrating an example of a first subframe within a 5G / NR frame structure. Figure 2B FIG230 is a diagram illustrating an example of DL channels within a 5G / NR subframe. Figure 2C Figure 250 shows 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 may 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 the 5G / NR frame structure may be 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 、 Figure 2C In the example provided, the 5G / NR frame structure is assumed to be TDD, subframe 4 is configured with time slot format 28 (primarily DL), where D is DL, U is UL, and X is flexibly used between DL / UL, and subframe 3 is configured with time slot format 34 (primarily UL). Although subframes 3 and 4 are shown as having time slot formats 34 and 28, respectively, any particular subframe can be configured with any of the various available time slot formats 0-61. Time slot formats 0 and 1 are DL and UL, respectively. Other time slot formats 2-61 include a mix of DL, UL and flexible symbols. The UE is configured with the time slot format via the received time slot format indicator (SFI) (dynamically via DL control information (DCI), or semi-statically / statically via radio resource control (RRC) signaling). It should be noted that the description of (infra) below also applies to the 5G / NR frame structure of TDD.

[0047] 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. Depending on the slot configuration, each time slot may include 7 or 14 symbols. For slot configuration 0, each time slot may include 14 symbols, while for 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 slots in a subframe is based on the slot configuration and numerology. For slot configuration 0, different numerical parameters μ0 to 5 allow 1, 2, 4, 8, 16, and 32 slots per subframe, respectively. For slot configuration 1, different numerical parameters 0 to 2 allow 2, 4, and 8 slots per subframe, respectively. Thus, for slot configuration 0 and numerical parameter μ, there are 14 symbols / slot and 2 μ time slots / subframes. The subcarrier spacing and symbol length / duration are functions of digital parameters. The subcarrier spacing can be equal to 2 μ *15kHz, where μ is a digital parameter 0 to 5. Thus, a digital parameter μ=0 has a subcarrier spacing of 15kHz, and a digital parameter μ=5 has a subcarrier spacing of 480kHz. The symbol length / duration is inversely proportional to the subcarrier spacing. Figures 2A to 2D An example is provided for slot configuration 0 with 14 symbols per slot and a numerical parameter μ = 0 with 1 slot per subframe. The subcarrier spacing is 15 kHz and the symbol duration is approximately 66.7 μs.

[0048] A resource grid can be used to represent the frame structure. Each time 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.

[0049] like Figure 2A As shown, some REs carry the reference (pilot) signals (RS) of the UE. RS may include demodulation RS (DM-RS) (denoted 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) for channel estimation at the UE. The RS may also include a beam measurement RS (BRS), a beam refinement RS (BRRS), and a phase tracking RS (PT-RS).

[0050] Figure 2B Examples of various DL channels within a subframe of a frame are shown. The physical downlink control channel (PDCCH) carries DCI within one or more control channel elements (CCEs), each CCE includes nine RE groups (REGs), and each REG includes four consecutive REs in an OFDM symbol. The primary synchronization signal (PSS) can be within symbol 2 of a specific subframe of the frame. The UE 104 uses the PSS to determine the subframe / symbol timing and the physical layer identification. The secondary synchronization signal (SSS) can be within symbol 4 of a specific subframe of the frame. The UE uses the SSS to determine the physical layer cell identification group number and the radio frame timing. Based on the physical layer identification and the physical layer cell identification group number, the UE can determine the physical cell identifier (PCI). Based on the PCI, the UE can determine the position of the above-mentioned 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 sent through the PBCH (such as System Information Blocks (SIBs)), and paging messages.

[0051] like Figure 2C As shown, some REs carry DM-RS (denoted as R for one specific configuration, but other DM-RS configurations are possible) for channel estimation at the base station. The UE can send DM-RS for the physical uplink control channel (PUCCH) and DM-RS for the physical uplink shared channel (PUSCH). The PUSCH DM-RS can be sent in the first one or two symbols of the PUSCH. Depending on whether a short PUCCH or a long PUCCH is sent and on the specific PUCCH format used, the PUCCH DM-RS can be sent in different configurations. Although not shown, the UE can send a sounding reference signal (SRS). The SRS can be used by the base station for channel quality estimation to enable frequency-dependent scheduling on the UL.

[0052] Figure 2DAn example of various UL channels within a subframe of a frame is shown. In one configuration, the PUCCH may be positioned as indicated. The PUCCH carries uplink control information (UCI), such as scheduling requests, channel quality indicator (CQI), precoding matrix indicator (PMI), rank indicator (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.

[0053] Figure 3 3 is a block diagram of a base station 310 communicating with a UE 350 in an access network. In the DL, IP packets from the EPC 160 may be provided to a controller / processor 375. The controller / processor 375 implements layer 3 and layer 2 functions. Layer 3 includes the 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 functions 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 functions associated with header compression / decompression, security (ciphering, deciphering, integrity protection, integrity verification), and handover support functions; RLC layer functions associated with transmission of upper layer packet data units (PDUs), error correction through ARQ, concatenation, segmentation and reassembly of RLC service data units (SDUs), re-segmentation of RLC data PDUs, and reordering of RLC data PDUs; and MAC layer functions 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.

[0054] The transmit (TX) processor 316 and receive (RX) processor 370 implement layer 1 functions associated with various signal processing functions. Layer 1, including the physical (PHY) layer, may include error detection on the transmission channel, forward error correction (FEC) encoding / decoding of the transmission channel, interleaving, rate matching, mapping to the physical channel, modulation / demodulation of the physical channel, and MIMO antenna processing. The TX processor 316 processes 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 coded and modulated symbols can then be divided into parallel streams. Each stream can 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 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 produce multiple spatial streams. Channel estimates from channel estimator 374 may be used to determine coding and modulation schemes, as well as for spatial processing. Channel estimates may be derived from reference signals and / or channel condition feedback transmitted by 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 its own spatial stream for transmission.

[0055] At the UE 350, each receiver 354RX receives a signal via its respective 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 functions associated with various signal processing functions. The RX processor 356 can 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 can be combined into a single OFDM symbol stream by the RX processor 356. 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 and reference signals on each subcarrier are recovered and demodulated by determining the most likely signal cluster point transmitted by the base station 310. These soft decisions can be based on channel estimates calculated by the channel estimator 358. The soft decisions are then decoded and deinterleaved to recover the data and control signals originally sent on the physical channel by base station 310. The data and control signals are then provided to controller / processor 359, which performs layer 3 and layer 2 functions.

[0056] 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, decryption, 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 an ACK and / or NACK protocol to support HARQ operations.

[0057] Similar to the functions described in conjunction with the DL transmission of the base station 310, the controller / processor 359 provides RRC layer functions associated with system information (e.g., MIB, SIB) acquisition, RRC connection, and measurement reporting; PDCP layer functions associated with header compression / decompression, security (encryption, decryption, integrity protection, integrity verification); RLC layer functions associated with transmission of upper layer PDUs, error correction through ARQ, concatenation, segmentation and reassembly of RLC SDUs, re-segmentation of RLC data PDUs, and reordering of RLC data PDUs; and MAC layer functions associated with mapping between logical channels and transport channels, multiplexing of MAC SDUs onto TBs, demultiplexing of MAC SDUs from TBs, scheduling information reporting, error correction through HARQ, priority handling, and logical channel prioritization.

[0058] The TX processor 368 may select an appropriate coding and modulation scheme and facilitate spatial processing using channel estimates derived by the channel estimator 358 from a reference signal or feedback transmitted by the base station 310. 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.

[0059] 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 a RX processor 370.

[0060] 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, decryption, 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 an ACK and / or NACK protocol to support HARQ operations.

[0061] At least one of the TX processor 368, the RX processor 356, and the controller / processor 359 may be configured to perform operations related to Figure 1 198 related aspects.

[0062] At least one of the TX processor 316, the RX processor 370, and the controller / processor 375 may be configured to perform operations related to Figure 1 199 related aspects.

[0063] In wireless communication systems, such as but not limited to mmW systems, base stations can perform transmissions in a directional manner, where the transmissions are beamformed to steer the beam in different directions. Beamforming can mitigate the high path loss at higher frequencies. In mmW systems, the carrier frequency is high, which results in shorter wavelengths, allowing the use of a greater number of antennas in the antenna array of a UE or base station. Due to the increased number of antennas, beamforming can be used to change the direction of the beam by applying different phases to different antennas.

[0064] One challenge in using beamforming for mmW systems can be the directionality of the beamformed beam. Due to the directionality of the beamformed beam, the base station should point the beam directly toward the UE so that the direction of the beam is aligned with the UE's location to provide more antenna receive gain at the UE. If the beam direction is not aligned correctly, the antenna gain at the UE may be reduced (e.g., resulting in low SNR, higher block error rate, etc.).

[0065] Using beamforming technology, the base station can select one of the beam sets pointing in different directions to communicate the selected beam. After the selection of the beam, the best beam can change, and the base station can therefore determine to change from the current beam to another beam. During the beam change process, the base station can send a beam change instruction to the UE to indicate that the base station intends to change from the current beam to another beam. The base station needs to ensure that the UE has correctly received the beam change instruction, and can require the base station to switch the beam only after receiving a confirmation confirming the receipt of the beam change instruction from the UE. The UE can receive the beam change instruction from the base station and send a confirmation to the base station. However, the uplink signal from the UE to the base station may encounter problems, so that the base station may not successfully receive the confirmation from the UE.

[0066] Figure 4FIG400 is a diagram illustrating a beam changing process according to certain aspects of the present disclosure. FIG400 includes an example of control beam switching via a MAC control element (CE) (MAC-CE) or DCI, wherein the base station may switch the control beam (e.g., 406) after receiving an ACK (e.g., 408) from the UE. In some instances, a set of possible beams (e.g., candidate beams) in the NR may be configured via RRC, and the MAC-CE or DCI may configure at least some communications on one of the beams in the possible beam set (e.g., the MAC-CE or DCI may indicate the selected beam). For example, the RRC message may indicate the set of possible (or candidate) beams as a transmission configuration indicator (TCI) state set, wherein each possible beam corresponds to a respective TCI state. In some further examples, the MAC-CE or DCI may indicate the configured TCI state, which may correspond to the beam to be used by the base station. The UE sending the ACK 408 to the base station provides the base station with the necessary confirmation to switch to the new beam (e.g., 414).

[0067] refer to Figure 4 , base station 402 may transmit a downlink signal 405, which may include a beam switching signal (e.g., a MAC-CE). The downlink signal 405 with the beam switching signal may be transmitted by base station 402 using first beam 406. UE 404 may receive downlink signal 405 with the beam switching signal. After decoding downlink signal 405 with the beam switching signal, UE 404 may transmit ACK 408 to base station 402. ACK 408 is delivered on the uplink or PUCCH, but is intended to provide an acknowledgement of downlink signal 405 received via a downlink channel (e.g., PDSCH). After receiving ACK 408, base station 402 may switch to a new beam (e.g., 414). UE 404 may also switch to a new beam (e.g., 412) corresponding to the new beam (e.g., 414) of base station 402.

[0068] If the UE's uplink beam is blocked or does not have sufficient coverage, then Figure 4 The example beam switching process may not work. As such, ACK 408 may not be correctly received by base station 402. The base station must receive ACK 408 from the UE in order to switch to the new beam. If ACK 408 is not received correctly, the UE may believe that the downlink beam at the base station is changing, but because the base station did not receive the ACK correctly, the base station will not change its beam. As such, because the base station did not receive the ACK, the base station and the UE may experience misalignment and may be unable to communicate with each other.

[0069] The present disclosure relates to improving the way a UE sends an ACK to a base station by utilizing coverage enhancement to send an ACK to the base station to confirm a beam change instruction. In some aspects, the UE can change its configuration for sending ACK by utilizing at least one of the coverage enhancements. The coverage enhancement can increase the likelihood that an ACK sent by the UE to the base station is received by the base station. For example, 12A to 12D The diagram of FIG provides an example of coverage enhancement that a UE can utilize to send an ACK to acknowledge a DL signal from a base station with a transmitted beam change or beam switching signal. Figure 12A In FIG. 1 , diagram 1200 discloses coverage enhancement, where the UE may be configured to send ACK in additional time resources within the PUCCH. Figure 12A As shown in the aspect of the present invention, the ACK (eg, ACK ce ) can be sent in one or more resource blocks of a subframe (e.g., subframe 3), so that ACK is sent simultaneously on different frequency resources. Compared with sending ACK only once, repeated transmission of ACK can allow the base station to correctly receive ACK. Figure 12B In FIG1220, ACK with coverage enhancement (eg, ACK ce ) can be sent by the UE at different times so that the ACK is sent in different subframes. Figure 12C In FIG1240 , the UE sends a first ACK, which confirms the reception of the DL signal but does not confirm the transmit beam change from the base station. After the transmission of the first ACK and the decoding of the DL signal, the UE may send an ACK with coverage enhancement to confirm the transmit beam change from the base station. Figure 12C In terms of coverage enhancement, the UE can utilize the coverage enhancement of sending ACK multiple times on different frequency resources. Figure 12D In diagram 1260 of FIG, the UE may deliver an ACK with coverage enhancement, wherein the coverage enhancement includes repeated transmission of the ACK at different frequency ranges or time instances. Figure 12D In terms of ACK, ACK is sent twice in subframe 3 and may also be sent twice in subframe 9. 12A to 12D The aspects provided in the are examples and are not intended to be an exhaustive list of coverage enhancements. The present disclosure is not intended to be limited to the aspects provided herein.

[0070] Figure 5 An example communication flow 500 between a UE 502 and a base station 504 is shown. Optional aspects are shown with dashed lines. The base station 504 may provide a cell serving the UE 502. For example, Figure 1In the context of , base station 504 may correspond to base station 102 / 180, and thus, a cell may include a geographic coverage area 110 where communication coverage is provided and / or a small cell 102' having a coverage area 110'. Further, UE 502 may correspond to at least UE 104. In another example, in Figure 3 In the context of , base station 504 may correspond to base station 310 and UE 502 may correspond to UE 350.

[0071] The base station 504 may send a downlink (DL) signal 506 including a beam switching signal to the UE 502. The beam switching signal may indicate that the base station 504 will change the transmit beam used for downlink communication with the UE 502. In some aspects, the base station may send an RRC configuration indicating coverage enhancement (e.g., an RRC message indicating coverage enhancement). The coverage enhancement indicated in the RRC configuration may indicate to the UE 502 the coverage enhancement for sending an ACK to confirm receipt of the beam switching signal. In some aspects, the base station may generate the beam switching signal to include a configuration indicating to the UE whether to use coverage enhancement to send an ACK. In some aspects, the base station may generate the beam switching signal to include a configuration indicating the coverage enhancement for sending an ACK. In some aspects, the base station may send an indication to the UE via a DCI regarding whether to use coverage enhancement to send an ACK.

[0072] After receiving the DL signal 506 from the base station 504, the UE 502 may decode the DL signal 506 at 508 after receiving the DL signal 506. The UE 502 may check a first cyclic redundancy check (CRC) generated based on the decoded DL signal 506 against a second cyclic redundancy check (CRC) within the DL signal 506. In instances where the first CRC matches the second CRC, the UE 502 may send a first ACK 510 to the base station 504. The first ACK 510 may be sent to the base station 504 without coverage enhancement. The base station 504 may receive the first ACK 510 from the UE, the first ACK 510 being configured to confirm receipt of the DL signal 506. The received ACK 518 confirming receipt of the transmit beam change is a second ACK received by the base station 504 after the first ACK 510. In some instances, for example, if the first CRC does not match the second CRC, the UE 502 may not send the first ACK, but may send a negative ACK (NACK). In such an aspect, if the base station 504 receives a NACK, the base station 504 may retransmit the DL signal 506 to the UE 502 .

[0073] At 512, UE 502 may be configured to determine that DL signal 506 includes a beam switching signal indicating that base station 504 will change the transmit beam used for downlink communication with UE 502. Base station 504 may transmit the beam switching signal to optimize the beam used for communication with UE 502.

[0074] At 514, based on the determination that the DL signal 506 includes a beam switching signal, the UE 502 may determine to send an ACK in the PUCCH with coverage enhancement to confirm the transmit beam change of the base station 504, e.g., 12A to 12D As discussed in . In some aspects, after the UE 502 sends the first ACK 510, the DL signal 506 can be determined to include a beam switching signal, and the ACK 518 sent in the PUCCH with coverage enhancement is a second ACK sent after the first ACK 510. The coverage enhancement can include at least one of sending the ACK in additional time or frequency resources within the PUCCH, or repeating the transmission of the ACK at different frequency ranges or time instances within the PUCCH. In some aspects, the coverage enhancement of repeating the transmission of the ACK at different frequency ranges or time instances can include sending the ACK in each beam of a plurality of different beams. In some aspects, the beam switching signal can include a configuration indicating whether the UE is to use coverage enhancement to send the ACK. In some aspects, the beam switching signal can include a configuration indicating the coverage enhancement to be used by the UE to send the ACK. The additional time or frequency resources within the PUCCH can include a second set of time and frequency resources having a larger number of resources than the first set of time and frequency resources used for the transmission of the standard ACK. The second set of time and frequency resources can be a superset of the first set of time and frequency resources.

[0075] In some aspects, for example, at 516, the UE 502 may change the configuration for sending the ACK 518. Based on a determination that the DL signal includes a beam switching signal, the UE may change the configuration for sending the ACK from a first configuration to a second configuration. In some aspects, the first configuration may be configured without coverage enhancement, and the second configuration may be configured to include coverage enhancement. In some aspects, the UE may receive an RRC configuration indicating a beam set for sending repeated ACKs. In such aspects, the multiple beams may be a subset of the beam set. In some aspects, the UE may receive an RRC configuration indicating a coverage enhancement that the UE may use for sending the ACK. In some aspects, the UE may receive an indication of whether to use coverage enhancement to send the ACK via DCI in the PDCCH.

[0076] After determining the configuration for coverage enhancement for sending an ACK, the UE 502 sends an ACK 518 to the base station 504 in the PUCCH with coverage enhancement. Coverage enhancement can increase the likelihood that the base station 504 receives the ACK 518. As discussed above, coverage enhancement can deliver the ACK 518 (e.g., the second ACK) more than once based on the repetition configuration. In some aspects, coverage enhancement can include sending the ACK 518 (e.g., the second ACK) over a longer symbol duration. Coverage enhancement can utilize more time and / or frequency resources to send the PUCCH, which may result in the use of a lower code rate and / or modulation and coding scheme. In some aspects, coverage enhancement can include repeating the same PUCCH over multiple frequency ranges and / or time instances and / or beams. In instances where the PUCCH is repeated over multiple beams, the beam set can be configured by RRC or can be selected as a pre-specified beam subset. For example, the two beams with the lowest index in the configured beam set.

[0077] The base station 504 receives an ACK 518 from the UE 502 confirming receipt of the transmit beam change of the base station 504. The ACK 518 is received with coverage enhancement. The coverage enhancement may include receiving the ACK 518 in additional time or frequency resources within the PUCCH, or receiving the ACK 518 multiple times in different frequency ranges or time instances within the PUCCH.

[0078] After the ACK 518 has been delivered to the base station 504 with the coverage enhancement, the UE 502 may switch beams at 520 to communicate on the downlink with the base station 504 via the new transmit beam. The new transmit beam may be based on the received transmit beam change and the transmitted ACK 518.

[0079] After the ACK 518 is received, the base station 504 may also switch beams at 522 , where based on the transmitted transmit beam change and based on the received ACK 518 , the base station 504 switches the transmit beam used for downlink communication with the UE 502 .

[0080] Figure 6600 is a flow chart of a method for wireless communication. The method may be performed by a UE or a component of a UE (e.g., UE 104, 350, 502, 1050; apparatus 702 / 702'; processing system 814, which may include memory 360 and may be the entire UE 350 or a component of UE 350, such as TX processor 368, RX processor 356, and / or controller / processor 359). According to various aspects, one or more of the illustrated operations of method 600 may be omitted, swapped, and / or performed concurrently. Optional aspects are shown in dashed lines. The method may enable the UE to utilize coverage enhancement to send an ACK to a base station to confirm a beam changing instruction.

[0081] At 602, a UE may receive a downlink signal. In some aspects, the UE may receive information from a base station indicating a beam switch from a first beam to a second beam, where the UE communicates with the base station via the first beam. For example, the downlink signal may include information indicating a beam switch from a first beam to a second beam, where the UE communicates with the base station via the first beam. For example, 602 may be performed by receiving component 704 of apparatus 702. The UE may receive a downlink signal from the base station.

[0082] In some aspects, for example, at 604, the UE may decode the DL signal after receiving the DL signal. That is, the UE may determine that the received DL signal includes information indicating a beam switch from a first beam via which the UE communicates with the base station to a second beam. For example, first, the UE may process the DL signal, such as by converting the DL signal from analog to digital; second, the UE may identify information in the DL signal corresponding to a beam index (e.g., TCI state(s)) of a beam that may be different from another beam via which the UE is currently (or most recently) communicating with the base station. For example, 604 may be performed by the decoding component 706 of the apparatus 702.

[0083] In some aspects, the UE may check a first cyclic redundancy check (CRC) generated based on the decoded DL signal, for example at 606. For example, 606 may be performed by the CRC component 708 of the apparatus 702. The UE may check the first CRC generated based on the decoded DL signal against a second CRC within the DL signal.

[0084] In some aspects, for example, at 608, the UE may send a first ACK to the base station. For example, 608 may be performed by the first ACK component 710 of the apparatus 702. After determining that the first CRC matches the second CRC, the UE may send the first ACK to the base station. In some aspects, the first ACK may be sent by the UE to the base station without utilizing coverage enhancement.

[0085] At 610, the UE may determine that the DL signal includes a beam switching signal. For example, 610 may be performed by the beam switching component 712 of the apparatus 702. The beam switching signal may indicate that the base station may change the transmit beam used for downlink communication with the UE. The base station may send the beam switching signal to optimize the beam used for communication with the UE.

[0086] At 612, the UE may determine to send an ACK in a PUCCH with coverage enhancement to confirm the base station's transmit beam change. For example, 612 may be performed by the coverage enhancement component 714 of the device 702. Based on a determination that the DL signal includes a beam switching signal, the UE may determine to send an ACK in a PUCCH with coverage enhancement. In some aspects, after the UE sends a first ACK, the UE may determine that the DL signal includes a beam switching signal and that the ACK sent in the PUCCH with coverage enhancement is a second ACK sent after the first ACK. The coverage enhancement may include sending the ACK in an additional time or frequency resource within the PUCCH, or repeating at least one of the transmission of the ACK at different frequency ranges or time instances within the PUCCH. In some aspects, the coverage enhancement of repeating the transmission of the ACK at different frequency ranges or time instances may include sending the ACK in each beam of a plurality of different beams. In some aspects, the beam switching signal may include a configuration indicating whether the UE is to use coverage enhancement to send the ACK. In some aspects, the beam switching signal may include a configuration indicating the coverage enhancement to be used by the UE to send the ACK. The additional time or frequency resources within the PUCCH may include a second set of time and frequency resources having a larger number of resources than the first set of time and frequency resources used for transmission of a standard ACK (eg, the first ACK 510).

[0087] The second set of time and frequency resources may be a superset of the first set of time and frequency resources.

[0088] In some aspects, for example, at 614, the UE may change the configuration for sending ACKs. For example, 614 may be performed by configuration component 716 of apparatus 702. Based on a determination that the DL signal includes a beam switching signal, the UE may change the configuration for sending ACKs from a first configuration to a second configuration. In some aspects, the first configuration may be configured without coverage enhancement, and the second configuration may be configured to include coverage enhancement. In some aspects, the UE may receive an RRC configuration indicating a beam set for transmitting repeated ACKs. In such aspects, the plurality of beams may be a subset of the beam set.

[0089] In some aspects, for example, at 616, the UE may receive an RRC configuration indicating coverage enhancement that the UE may use to send an ACK. For example, 616 may be performed by RRC component 718 of apparatus 702. Some or all parameters for coverage enhancement may be configured by the RRC configuration received by the UE. For example, a set of repetition options for sending an ACK may be defined in the RRC configuration.

[0090] In some aspects, the UE may receive an indication of whether to send an ACK using coverage enhancement via DCI, for example, at 618. For example, 618 may be performed by DCI component 720 of apparatus 702. The UE may receive the DCI in a PDCCH.

[0091] At 620, the UE may send an ACK in a PUCCH with coverage enhancement. In some aspects, based on information indicating a beam switch (see, e.g., 602), the UE may send two or more ACK messages to the base station on a control channel (e.g., PUCCH), and the two or more ACK messages may confirm receipt of the information indicating the beam switch from the base station. For example, 620 may be performed by the second ACK component 722 of the device 702. The UE may send an ACK to the base station in a PUCCH with coverage enhancement. Coverage enhancement may increase the likelihood that the base station receives the ACK. As discussed above, coverage enhancement may send an ACK (e.g., a second ACK) more than once based on a repetition configuration. In some aspects, coverage enhancement may include sending an ACK (e.g., a second ACK) over a longer symbol duration. Coverage enhancement may utilize more time and / or frequency resources to send the PUCCH, which may result in the use of a lower code rate and / or modulation and coding scheme. In some aspects, coverage enhancement may include repeating the same PUCCH over multiple frequency ranges and / or time instances and / or beams. In instances where the PUCCH is repeated on multiple beams, the beam set may be configured by RRC or may be selected as a subset of pre-specified beams, for example, the two beams with the lowest indices in the configured beam set.

[0092] In some aspects, the UE may communicate with the base station on the DL via the new transmit beam, for example, at 622. For example, 622 may be performed by the new beam component 724 of the apparatus 702. The new transmit beam may be based on the received transmit beam change and the transmitted ACK (e.g., the second ACK).

[0093] In some aspects, a UE may receive information from a base station indicating a beam switch from a first beam to a second beam, wherein the UE communicates with the base station via the first beam. In some aspects, based on the information indicating the beam switch, the UE may send two or more ACK messages to the base station on a control channel, and the two or more ACK messages acknowledge receipt of the information indicating the beam switch from the base station. In some aspects, the control channel is at least one of a physical uplink control channel (PUCCH) or an enhanced physical uplink control channel (ePUCCH).

[0094] In some aspects, sending, by the UE, the two or more ACK messages on the control channel to the base station may include sending, by the UE, at least two of the two or more ACK messages in two or more resource blocks of a subframe. In some aspects, sending, by the UE, the two or more ACK messages on the control channel to the base station may include sending, by the UE, at least two of the two or more ACK messages in two or more subframes.

[0095] In some aspects, sending two or more ACK messages by the UE to the base station on the control channel may include sending at least one ACK message of the two or more ACK messages by the UE on a first frequency in a first subframe, and sending at least another ACK message of the two or more ACK messages by the UE on a second frequency in a second subframe.

[0096] In some aspects, sending two or more ACK messages by the UE to the base station on the control channel may include sending a first set of at least two ACK messages of the two or more ACK messages by the UE on different frequencies of a first subframe, and sending a second set of at least two ACK messages of the two or more ACK messages by the UE on different frequencies of a second subframe.

[0097] In some aspects, sending, by the UE, the two or more ACK messages on the control channel to the base station may include sending, by the UE, at least one ACK message of the two or more ACK messages within each beam of a plurality of beams. In some aspects, the UE may receive, from the base station, an RRC message indicating a beam set for sending the two or more ACK messages to the base station, wherein the plurality of beams is a subset of the beam set.

[0098] In some aspects, the UE may change a configuration for sending ACK messages from a first configuration to a second configuration based on information received from the base station, where the second configuration indicates sending two or more ACK messages.

[0099] Figure 7is a conceptual data flow diagram 700 illustrating the flow of data between different parts / components in an example apparatus 702. The apparatus may be a UE or a component of a UE. The apparatus includes a receiving component 704 that may be configured to receive various types of signals / messages and / or other information from other devices including, for example, a base station 750. The receiving component 704 may receive DL signals from the base station, for example, as described in conjunction with Figure 6 The apparatus includes a decoding component 706, which can decode the DL signal after receiving the DL signal, for example, as described in conjunction with Figure 6 The apparatus includes a CRC component 708 that can check a first CRC generated based on the decoded DL signal, for example, as described in conjunction with Figure 6 The apparatus includes a first ACK component 710 that can send a first ACK to the base station after determining that the first CRC matches the second CRC, for example, as described in conjunction with Figure 6 The apparatus includes a beam switching component 712 that can determine that the DL signal includes a beam switching signal indicating that the base station will change the transmit beam used for downlink communication with the UE, for example, as described in conjunction with Figure 6 The apparatus includes a coverage enhancement component 714 that can determine to send an ACK in a PUCCH with coverage enhancement to confirm the change of the transmission beam of the base station, for example, as combined with Figure 6 The apparatus includes a configuration component 716 that, based on a determination that the DL signal includes a beam switching signal, can change a configuration for sending an ACK from a first configuration to a second configuration, for example, as described in conjunction with Figure 6 The apparatus includes an RRC component 718 that can receive an RRC configuration indicating the coverage enhancement for sending an ACK, for example, as described in conjunction with Figure 6 The apparatus includes a DCI component 720 that can receive an indication of whether to use coverage enhancement to send ACK via a DCI in a PDCCH, for example, as described in conjunction with Figure 6 The apparatus includes a second ACK component 722 that can send an ACK in a PUCCH with coverage enhancement to the base station, for example, as described in conjunction with Figure 6 The apparatus includes a new beam component 724 that can communicate with the base station on the DL via a new transmit beam, for example, as described in conjunction with Figure 6The apparatus includes a transmitting component 726 that can be configured to transmit various types of signals / messages and / or other information to other devices including, for example, the base station 750 .

[0100] The apparatus may include performing the above Figure 6 The additional components of each of the blocks in the algorithm in the flowchart. Figure 6 Each block in the flowchart of can be performed by a component, and the apparatus can include one or more of these components. These components can be one or more hardware components that are specifically configured to perform the above-described processes / algorithms, implemented by a processor configured to perform the above-described processes / algorithms, stored in a computer-readable medium for implementation by a processor, or some combination thereof.

[0101] Figure 8 FIG800 is a diagram illustrating an example of a hardware implementation of an apparatus 702′ employing a processing system 814. The processing system 814 may be implemented using a bus architecture, generally represented by a bus 824. Depending on the specific application and overall design constraints of the processing system 814, the bus 824 may include any number of interconnecting buses and bridges. The bus 824 connects various circuits (represented by the processor 804, components 704, 706, 708, 710, 712, 714, 716, 718, 720, 722, 724, 726, and computer-readable medium / memory 806) including one or more processors and / or hardware components. The bus 824 may also connect various other circuits, such as timing sources, peripherals, voltage regulators, and power management circuits, which are well known in the art and therefore not described further.

[0102] Processing system 814 may be coupled to transceiver 810. Transceiver 810 is coupled to one or more antennas 820. Transceiver 810 provides components for communicating with various other devices via a transmission medium. Transceiver 810 receives signals from one or more antennas 820, extracts information from the received signals, and provides the extracted information to processing system 814, specifically, receiving component 704. Furthermore, transceiver 810 receives information from processing system 814 (specifically, transmitting component 726) and, based on the received information, generates signals to be applied to one or more antennas 820. Processing system 814 includes processor 804 coupled to computer-readable medium / memory 806. Processor 804 is responsible for general processing, including executing software stored in computer-readable medium / memory 806. When executed by processor 804, this software enables processing system 814 to perform the various functions described above for any particular device. Computer-readable medium / memory 806 may also be used to store data, which is manipulated by processor 804 when executing the software. The processing system 814 also includes at least one of the components 704, 706, 708, 710, 712, 714, 716, 718, 720, 722, 724, 726. These components may be software components running in the processor 804, located / stored in the computer-readable medium / memory 806, one or more hardware components coupled to the processor 804, or some combination thereof. The processing system 814 may be a component of the UE 350 and may include the memory 360 and / or at least one of the TX processor 368, the RX processor 356, and the controller / processor 359. Alternatively, the processing system 814 may be the entire UE (e.g., see Figure 3 of 350).

[0103] In one configuration, an apparatus 702 / 702' for wireless communication includes means for receiving a downlink (DL) signal from a base station. The apparatus includes means for determining that the DL signal includes a beam switching signal, the beam switching signal indicating that the base station will change a transmit beam used for downlink communication with a UE. The apparatus includes means for determining, based on the determination that the DL signal includes the beam switching signal, to send an ACK in a PUCCH with coverage enhancement to acknowledge the base station's transmit beam change. The coverage enhancement includes at least one of sending the ACK in additional time or frequency resources within the PUCCH or repeating the transmission of the ACK at different frequency ranges or time instances within the PUCCH. The apparatus includes means for sending an ACK in the PUCCH with coverage enhancement to the base station. The apparatus also includes means for decoding the DL signal after receiving the DL signal. The apparatus also includes means for checking a first CRC generated based on the decoded DL signal against a second CRC within the DL signal. The apparatus also includes means for sending a first ACK to the base station after determining that the first CRC matches the second CRC. The apparatus also includes means for determining, after sending the first ACK, that the DL signal includes the beam switching signal. The ACK sent with coverage enhancement is a second ACK sent after the first ACK. The apparatus also includes a component for changing the configuration for sending the ACK from a first configuration to a second configuration based on a determination that the DL signal includes a beam switching signal. The first configuration does not have coverage enhancement, and the second configuration has coverage enhancement. The apparatus also includes a component for receiving an RRC configuration indicating a beam set for sending repeated ACKs. The multiple beams are a subset of the beam set. The apparatus also includes a component for receiving an RRC configuration indicating coverage enhancement for sending ACKs. The apparatus also includes a component for receiving an indication of whether to send the ACK using coverage enhancement via a DCI in a PDCCH. The apparatus also includes a component for communicating with the base station on the DL via a new transmit beam, the new transmit beam being based on the received transmit beam change and the transmitted ACK. The aforementioned component may be one or more of the aforementioned components of the apparatus 702 and / or the processing system 814 of the apparatus 702′, the processing system 814 being configured to perform the functions listed by the aforementioned component. As described supra, the processing system 814 may include the TX processor 368, the RX processor 356, and the controller / processor 359. Thus, in one configuration, the aforementioned components may be the TX processor 368, the RX processor 356, and the controller / processor 359 configured to perform the functions recited by the aforementioned components.

[0104] Figure 9900 is a flow chart of a method for wireless communication. The method may be performed by a base station or a component of a base station (e.g., base station 102, 180, 310, 504, 750; apparatus 1002 / 1002'; processing system 1114, which may include memory 376 and may be the entire base station 310 or a component of base station 310, such as TX processor 316, RX processor 370, and / or controller / processor 375). According to various aspects, one or more of the illustrated operations of method 900 may be omitted, swapped, and / or performed concurrently. The method may allow the base station to receive an ACK from a UE confirming receipt of a beam switching signal, wherein the ACK is received using coverage enhancement.

[0105] At 902, a base station may transmit a downlink signal including a beam switching signal. In some aspects, the base station may transmit information to a UE indicating a beam switch from a first beam to a second beam, wherein the UE communicates with the base station via the first beam. For example, 902 may be performed by beam switching component 1006 of apparatus 1002. The base station may transmit a downlink signal including a beam switching signal to the UE. The beam switching signal may indicate that the base station may change the transmit beam used for downlink communication with the UE.

[0106] In some aspects, for example, at 904, the base station may transmit an RRC configuration indicating coverage enhancement. For example, 904 may be performed by the RRC component 1008 of the apparatus 1002. The coverage enhancement indicated in the RRC configuration may indicate the coverage enhancement to the UE for sending an ACK. The ACK acknowledges receipt of the beam switching signal.

[0107] In some aspects, the base station may generate a beam switching signal to include a configuration indicating whether coverage enhancement is used, for example, at 906. For example, 906 may be performed by the configuration component 1010 of the apparatus 1002. The generated beam switching signal including the configuration may indicate to the UE whether coverage enhancement is used to send an ACK.

[0108] In some aspects, the base station may generate a beam switching signal to include a configuration indicating coverage enhancement, for example, at 908. For example, 908 may be performed by the coverage enhancement component 1012 of the apparatus 1002. The generated beam switching signal including the configuration may indicate to the UE the coverage enhancement for sending an ACK.

[0109] In some aspects, for example, at 910, the base station may send an indication to the UE via DCI whether to use coverage enhancement. For example, 910 may be performed by the DCI component 1014 of the apparatus 1002. The base station may send the indication via DCI in the PDCCH. The indication may indicate to the UE whether to use coverage enhancement to send an ACK.

[0110] In some aspects, for example, at 912, the base station may receive a first ACK from the UE confirming receipt of the DL signal. In some aspects, in response to the transmitted information indicating the beam switch (see, for example, 902), the base station may receive at least one ACK message from the UE on a control channel (e.g., a PUCCH), and the at least one ACK message may confirm receipt of the information indicating the beam switch from the base station. For example, 912 may be performed by the first ACK component 1016 of the apparatus 1002. The received ACK confirming receipt of the transmit beam change may be a second ACK received after the first ACK. In some aspects, the base station receives the first ACK without utilizing coverage enhancement.

[0111] At 914, the base station may receive an ACK from the UE confirming receipt of the base station's transmit beam change. In some aspects, in response to the transmitted information indicating the beam switch (see, for example, 902), the base station may receive at least one additional ACK message from the UE on a control channel, and the at least one additional ACK message may confirm receipt of the information indicating the beam switch from the base station. For example, 914 may be performed by the second ACK component 1018 of the apparatus 1002. The ACK may be received using coverage enhancement. In some aspects, the coverage enhancement may include receiving the ACK in additional time or frequency resources within the PUCCH, or receiving at least one of the ACKs multiple times in different frequency ranges or time instances within the PUCCH. In some aspects, the coverage enhancement of receiving the ACKs multiple times in different frequency ranges or time instances may include receiving the ACKs in each of a plurality of different beams. In some aspects, the base station may send an RRC configuration to the UE indicating a beam set for the UE to repeat the transmission of the ACK. The multiple beams may be a subset of the beams indicated by the RRC configuration. In some aspects, the additional time or frequency resources within the PUCCH may include a second set of time and frequency resources having a greater number of resources than the first set of time and frequency resources used for transmission of a standard ACK. The second set of time and frequency resources may be a superset of the first set of time and frequency resources.

[0112] In some aspects, the base station may switch the transmit beam used for DL ​​communication with the UE, for example, at 916. For example, 916 may be performed by the new beam component 1020 of the apparatus 1002. The base station may switch the transmit beam used for DL ​​communication with the UE based on the transmitted transmit beam change and the received ACK.

[0113] In some aspects, a base station may transmit information to a UE indicating a beam switch from a first beam to a second beam, wherein the UE communicates with the base station via the first beam. In some aspects, in response to the transmitted information indicating the beam switch, the base station may receive two or more ACK messages from the UE on a control channel, the two or more ACK messages acknowledging receipt of the information indicating the beam switch from the base station.

[0114] In some aspects, receiving, by the base station, two or more ACK messages from the UE on the control channel may include receiving, by the base station, at least two of the two or more ACK messages in two or more resource blocks of a subframe. In some aspects, receiving, by the base station, two or more ACK messages from the UE on the control channel may include receiving, by the base station, at least two of the two or more ACK messages in two or more subframes.

[0115] In some aspects, receiving two or more ACK messages from the UE on the control channel by the base station may include receiving at least one ACK message of the two or more ACK messages by the base station on a first frequency of a first subframe, and receiving at least another ACK message of the two or more ACK messages by the base station on a second frequency of a second subframe.

[0116] In some aspects, receiving two or more ACK messages from the UE on a control channel by the base station may include receiving a first set of at least two ACK messages of the two or more ACK messages by the base station on different frequencies of a first subframe, and receiving a second set of at least two ACK messages of the two or more ACK messages by the base station on different frequencies of a second subframe.

[0117] In some aspects, receiving, by the base station, two or more ACK messages from the UE on the control channel may include receiving, by the base station, at least one ACK message of the two or more ACK messages within each of a plurality of beams. In some aspects, the base station may send, to the UE, an RRC message indicating a beam set for receiving the two or more ACK messages from the UE, wherein the plurality of beams is a subset of the beam set.

[0118] Figure 10is a conceptual data flow diagram 1000 illustrating the flow of data between different parts / components in an example apparatus 1002. The apparatus can be a base station or a component of a base station. The apparatus includes a receiving component 1004 that can be configured to receive various types of signals / messages and / or other information from other devices including, for example, a UE 1050. The apparatus includes a beam switching component 1006 that can send a DL signal to the UE including a beam switching signal indicating that the base station will change the transmit beam used for downlink communication with the UE, for example, as described in conjunction with Figure 9 The apparatus includes an RRC component 1008 that sends an RRC configuration indicating coverage enhancement for sending an ACK to the UE, for example, as described in conjunction with Figure 9 The apparatus includes a configuration component 1010 that generates a beam switching signal to include a configuration indicating whether to use coverage enhancement to send ACK, for example, as described in conjunction with Figure 9 The apparatus includes a coverage enhancement component 1012 that generates a beam switching signal to include a configuration indicating coverage enhancement for sending an ACK, for example, as described in conjunction with Figure 9 The apparatus includes a DCI component 1014 that sends an indication to the UE via a DCI in the PDCCH whether to use coverage enhancement to send an ACK, for example, as described in conjunction with Figure 9 The apparatus includes a first ACK component 1016 that receives a first ACK from the UE confirming receipt of a DL signal, for example, as described in conjunction with Figure 9 The apparatus includes a second ACK component 1018 that can receive an ACK from the UE confirming the reception of the base station's transmit beam change, for example, as described in conjunction with Figure 9 The apparatus includes a new beam component 1020 that can switch a transmit beam for DL ​​communication with the UE, for example, as described in conjunction with Figure 9 The apparatus includes a transmitting component 1022 that can be configured to transmit various types of signals / messages and / or other information to other devices including, for example, a UE 1050.

[0119] The apparatus may include performing the above Figure 9 The additional components of each of the blocks in the algorithm in the flowchart. Figure 9Each block in the flowchart of can be performed by a component, and the apparatus can include one or more of these components. These components can be one or more hardware components that are specifically configured to perform the above-described processes / algorithms, implemented by a processor configured to perform the above-described processes / algorithms, stored in a computer-readable medium for implementation by a processor, or some combination thereof.

[0120] Figure 11 FIG1100 is a diagram illustrating an example of a hardware implementation for an apparatus 1002′ employing a processing system 1114. The processing system 1114 can be implemented using a bus architecture, generally represented by a bus 1124. Depending on the specific application and overall design constraints of the processing system 1114, the bus 1124 can include any number of interconnecting buses and bridges. The bus 1124 connects various circuits (represented by the processor 1104, components 1004, 1006, 1008, 1010, 1012, 1014, 1016, 1018, 1020, 1022, and computer-readable medium / memory 1106) including one or more processors and / or hardware components. The bus 1124 can also connect various other circuits, such as timing sources, peripherals, voltage regulators, and power management circuits, which are well known in the art and therefore not described further.

[0121] Processing system 1114 may be coupled to transceiver 1110. Transceiver 1110 is coupled to one or more antennas 1120. Transceiver 1110 provides components for communicating with various other devices via a transmission medium. Transceiver 1110 receives signals from one or more antennas 1120, extracts information from the received signals, and provides the extracted information to processing system 1114, specifically, receiving component 1004. Furthermore, transceiver 1110 receives information from processing system 1114 (specifically, transmitting component 1022) and, based on the received information, generates signals to be applied to one or more antennas 1120. Processing system 1114 includes processor 1104 coupled to computer-readable medium / memory 1106. Processor 1104 is responsible for general processing, including executing software stored in computer-readable medium / memory 1106. When executed by processor 1104, this software enables processing system 1114 to perform the various functions described above for any particular device. The computer-readable medium / memory 1106 may also be used to store data that is manipulated by the processor 1104 when executing software. The processing system 1114 also includes at least one of the components 1004, 1006, 1008, 1010, 1012, 1014, 1016, 1018, 1020, 1022. These components may be software components running in the processor 1104, located / stored in the computer-readable medium / memory 1106, one or more hardware components coupled to the processor 1104, or some combination thereof. The processing system 1114 may be a component of the base station 310 and may include the memory 376 and / or at least one of the TX processor 316, the RX processor 370, and the controller / processor 375. Alternatively, the processing system 1114 may be the entire base station (e.g., see Figure 3 310).

[0122] In one configuration, an apparatus 1002 / 1002' for wireless communication includes a component for sending a DL signal to a UE, the DL signal including a beam switching signal indicating that the BS will change the transmit beam used for downlink communication with the UE. The apparatus includes a component for receiving an ACK from the UE confirming the reception of the base station's transmit beam change. The ACK is received using coverage enhancement. The coverage enhancement includes at least one of receiving the ACK in additional time or frequency resources within a PUCCH, or receiving the ACK multiple times in different frequency ranges or time instances within the PUCCH. The apparatus also includes a component for receiving a first ACK from the UE confirming the reception of the DL signal. The received ACK confirming the reception of the transmit beam change is a second ACK received after the first ACK. The apparatus also includes a component for sending an RRC configuration indicating a beam set for the UE to repeat ACK transmission. The multiple beams are a subset of the beams indicated by the RRC configuration. The apparatus also includes a component for sending an RRC configuration indicating the coverage enhancement for sending the ACK to the UE. The apparatus also includes a component for generating a beam switching signal to include a configuration indicating to the UE whether coverage enhancement is used to send an ACK. The apparatus also includes a component for generating a beam switching signal to include a configuration indicating to the UE whether coverage enhancement is used to send an ACK. The apparatus also includes a component for sending an indication to the UE via DCI in the PDCCH whether coverage enhancement is used to send an ACK. The apparatus also includes a component for switching the transmit beam used for DL ​​communication with the UE based on the transmitted transmit beam change and the received ACK. The above-mentioned components may be one or more of the above-mentioned components of the apparatus 1002 and / or the processing system 1114 of the apparatus 1002′, the processing system 1114 being configured to perform the functions listed by the above-mentioned components. As described supra above, the processing system 1114 may include a TX processor 316, an RX processor 370, and a controller / processor 375. Thus, in one configuration, the above-mentioned components may be the TX processor 316, the RX processor 370, and the controller / processor 375, which are configured to perform the functions listed by the above-mentioned components.

[0123] The present disclosure relates to improving the manner in which a UE sends an ACK to a base station by utilizing coverage enhancement to send an ACK to the base station to confirm a beam change instruction. In some aspects, the UE can change its configuration for sending an ACK by utilizing at least one of the coverage enhancements. At least one advantage of the present disclosure is that the coverage enhancement can increase the likelihood that an ACK sent by the UE to the base station is received by the base station. For example, the coverage enhancement can include sending the ACK in additional time or frequency resources within the PUCCH, or repeating at least one of the transmission of the ACK at different frequency ranges or time instances within the PUCCH.

[0124] It should be understood that the specific order or hierarchy of blocks in the disclosed processes / flowcharts is illustrative of example methods. Based on design preferences, it should be understood that the specific order or hierarchy of blocks in the processes / flowcharts may be rearranged. In addition, some blocks may be combined or omitted. The accompanying method claims present elements of the various blocks in a sample order and are not meant to be limited to the specific order or hierarchy presented.

[0125] The foregoing description is provided to enable anyone skilled in the art to practice the various aspects described herein. Various modifications to these aspects will be apparent to those skilled in the art, and the general principles defined herein may be applied to other aspects. Therefore, the claims are not intended to be limited to the aspects shown herein, but rather to the full scope consistent with the language of the claims, wherein, unless otherwise specified, references to elements in the singular do not mean "one and only one," but rather "one or more." The word "exemplary" as used herein means "serving as an example, instance, or illustration." Any aspect described herein as "exemplary" is not necessarily to be construed as superior or better than other aspects. Unless 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 multiples of A, multiples of B, or multiples of C. 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 to the elements of the various aspects described throughout this disclosure that are known or later come to be known to those of ordinary skill in the art are expressly incorporated herein by reference and are intended to be encompassed by the claims. Furthermore, nothing disclosed herein is intended to be dedicated to the public regardless of whether such disclosure is expressly recited in the claims. Words such as "module," "mechanism," "element," "device," etc. may not be substituted for the word "component." Thus, no claim element is to be construed as part-plus-function unless the element is expressly recited using the phrase "component for..."

Claims

1. A method for wireless communication by a user equipment (UE), comprising: receiving information from a base station, the information indicating a beam switch from a first beam to a second beam, wherein the UE communicates with the base station via the first beam; as well as Based on the information indicating the beam switching, two or more acknowledgment (ACK) messages with different coverage enhancement configurations are sent to the base station on a control channel, the two or more ACK messages acknowledging receipt of the information indicating the beam switching from the base station.

2. The method according to claim 1, wherein Sending the two or more ACK messages to the base station on the control channel includes sending at least two of the two or more ACK messages in two or more resource blocks of a subframe.

3. The method according to claim 1, wherein Sending the two or more ACK messages to the base station on the control channel includes sending at least two of the two or more ACK messages in two or more subframes.

4. The method according to claim 1, wherein Sending the two or more ACK messages to the base station on the control channel includes: sending at least one ACK message of the two or more ACK messages on a first frequency in a first subframe; and At least another ACK message of the two or more ACK messages is sent on a second frequency in a second subframe.

5. The method according to claim 1, wherein Sending the two or more ACK messages to the base station on the control channel includes: sending a first set of at least two ACK messages of the two or more ACK messages on different frequencies in a first subframe; and A second set of at least two ACK messages of the two or more ACK messages are sent on different frequencies in a second subframe.

6. The method according to claim 1, wherein Sending the two or more ACK messages to the base station on the control channel includes sending at least one ACK message of the two or more ACK messages within each beam of a plurality of beams.

7. The method according to claim 6, further comprising: A radio resource control (RRC) message is received from the base station indicating a beam set for sending the two or more ACK messages to the base station, wherein the plurality of beams are a subset of the beam set.

8. The method according to claim 1, further comprising: Based on the received information, a configuration for sending ACK messages is changed from a first configuration to a second configuration, wherein the second configuration indicates sending the two or more ACK messages.

9. The method according to claim 1, wherein The control channel is a physical uplink control channel PUCCH.

10. The method according to claim 1, wherein Sending two or more ACK messages includes: sending a first ACK message without coverage enhancement, and at least one second ACK message with coverage enhancement, wherein the coverage enhancement includes at least one of: sending the ACK message in additional time or frequency resources, or repeatedly sending the ACK message in different frequency ranges, time instances, or beams.

11. An apparatus for wireless communication by a user equipment (UE), comprising: Memory; as well as at least one processor coupled to the memory and configured to: receiving information from a base station, the information indicating a beam switch from a first beam to a second beam, wherein the UE communicates with the base station via the first beam; as well as Based on the information indicating the beam switching, two or more acknowledgment (ACK) messages with different coverage enhancement configurations are sent to the base station on a control channel, the two or more ACK messages acknowledging receipt of the information indicating the beam switching from the base station.

12. The device according to claim 11, wherein The at least one processor is configured to send a first ACK message without coverage enhancement and at least one second ACK message with coverage enhancement, wherein the coverage enhancement includes at least one of sending the ACK message in additional time or frequency resources, or repeatedly sending the ACK message in different frequency ranges, time instances, or beams.

13. The device according to claim 11, wherein To send the two or more ACK messages to the base station on the control channel, the at least one processor is further configured to send at least two of the two or more ACK messages in two or more resource blocks of a subframe.

14. The device according to claim 11, wherein To send the two or more ACK messages to the base station on the control channel, the at least one processor is further configured to send at least two of the two or more ACK messages in two or more subframes.

15. The device according to claim 11, wherein To send the two or more ACK messages to the base station on the control channel, the at least one processor is further configured to: sending at least one ACK message of the two or more ACK messages on a first frequency in a first subframe; and At least another ACK message of the two or more ACK messages is sent on a second frequency in a second subframe.

16. The device according to claim 11, wherein To send the two or more ACK messages to the base station on the control channel, the at least one processor is further configured to: sending a first set of at least two ACK messages of the two or more ACK messages on different frequencies in a first subframe; and A second set of at least two ACK messages of the two or more ACK messages are sent on different frequencies in a second subframe.

17. The device according to claim 11, wherein To send the two or more ACK messages to the base station on the control channel, the at least one processor is further configured to send at least one ACK message of the two or more ACK messages within each beam of a plurality of beams.

18. The device according to claim 17, wherein The at least one processor is further configured to: A radio resource control (RRC) message is received from the base station indicating a beam set for sending the two or more ACK messages to the base station, wherein the plurality of beams are a subset of the beam set.

19. The device according to claim 11, wherein The at least one processor is further configured to: Based on the received information, a configuration for sending ACK messages is changed from a first configuration to a second configuration, wherein the second configuration indicates sending the two or more ACK messages.

20. The device according to claim 11, wherein The control channel is a physical uplink control channel PUCCH.

21. A method for wireless communication by a base station, comprising: sending information to a user equipment (UE), the information indicating a beam switch from a first beam to a second beam, wherein the UE communicates with the base station via the first beam; as well as In response to the transmitted information indicating the beam switching, two or more acknowledgment ACK messages with different coverage enhancement configurations are received from the UE on a control channel, the two or more ACK messages acknowledging receipt of the information indicating the beam switching from the base station.

22. The method according to claim 21, wherein A first ACK message among the two or more ACK messages is sent by the UE without utilizing coverage enhancement, and at least one second ACK message among the two or more ACK messages is sent by the UE with coverage enhancement, wherein the coverage enhancement includes at least one of: sending the ACK message in additional time or frequency resources, or repeatedly sending the ACK message in different frequency ranges, time instances, or beams.

23. The method according to claim 21, wherein Receiving the two or more ACK messages from the UE on the control channel further includes receiving at least two of the two or more ACK messages in two or more resource blocks of a subframe.

24. The method according to claim 21, wherein Receiving the two or more ACK messages from the UE on the control channel further includes receiving at least two ACK messages of the two or more ACK messages in two or more subframes.

25. The method according to claim 21, wherein Receiving the two or more ACK messages from the UE on the control channel further includes: receiving at least one ACK message of the two or more ACK messages on a first frequency in a first subframe; and At least another ACK message of the two or more ACK messages is received on a second frequency in a second subframe.

26. The method according to claim 21, wherein Receiving the two or more ACK messages from the UE on the control channel further includes: receiving a first set of at least two ACK messages of the two or more ACK messages on different frequencies in a first subframe; and A second set of at least two ACK messages of the two or more ACK messages is received on different frequencies in a second subframe.

27. The method according to claim 21, wherein Receiving the two or more ACK messages from the UE on the control channel further includes receiving at least one ACK message of the two or more ACK messages within each beam of a plurality of beams.

28. The method according to claim 27, further comprising: A radio resource control (RRC) message is sent to the UE indicating a beam set for receiving the two or more ACK messages from the UE, wherein the plurality of beams are a subset of the beam set.

29. An apparatus for wireless communication by a base station, comprising: Memory; as well as at least one processor coupled to the memory and configured to: sending information to a user equipment (UE), the information indicating a beam switch from a first beam via which the UE communicates with the base station to a second beam; and In response to the transmitted information indicating the beam switching, two or more acknowledgment ACK messages with different coverage enhancement configurations are received from the UE on a control channel, the two or more ACK messages acknowledging receipt of the information indicating the beam switching from the base station.

30. The apparatus according to claim 29, wherein To receive the two or more ACK messages from the UE on the control channel, the at least one processor is further configured to receive at least two of the two or more ACK messages in two or more resource blocks of a subframe.

31. The apparatus according to claim 29, wherein To receive the two or more ACK messages from the UE on the control channel, the at least one processor is further configured to receive at least two ACK messages of the two or more ACK messages in two or more subframes.

32. The apparatus of claim 29, wherein: To receive the two or more ACK messages from the UE on the control channel, the at least one processor is configured to: receiving at least one ACK message of the two or more ACK messages on a first frequency in a first subframe; as well as At least another ACK message of the two or more ACK messages is received on a second frequency in a second subframe.

33. The apparatus of claim 29, wherein: To receive the two or more ACK messages from the UE on the control channel, the at least one processor is configured to: receiving a first set of at least two ACK messages of the two or more ACK messages on different frequencies in a first subframe; as well as A second set of at least two ACK messages of the two or more ACK messages is received on different frequencies in a second subframe.

34. A computer-readable medium storing instructions for wireless communication at a user equipment, wherein the instructions are executable by one or more processors of the user equipment to cause the processors to perform the method according to any one of claims 1-10.

35. A computer-readable medium storing instructions for wireless communication at a base station, wherein the instructions are executable by one or more processors of the base station to cause the processors to perform the method according to any one of claims 21-28.

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