Preamble transmission in random access channel procedure

Abstract

Methods, systems, and devices for wireless communication are described. For example, a user equipment (UE) can transmit, to a base station, a first message of a RACH procedure. The UE can receive, from the base station, a second message of the RACH procedure based on the first message. The UE can transmit, to the base station, a preamble, a reference signal, or both, and a third message of the RACH procedure based on the second message. The UE can transmit the preamble, the reference signal, or both, prior to the transmission of the third message. In some cases, the UE can receive control signaling indicating whether to transmit both the preamble and the reference signal with the third message or not to transmit both with the third message. Additionally or alternatively, the control signaling can indicate resources for the preamble, the reference signal, or both, and resources for the third message.

Description

[0001] Cross-reference to related applications

[0002] This patent application claims the benefits of U.S. Provisional Patent Application No. 62 / 992,708, entitled "FRONT-LOADED TRANSMISSION IN A RANDOM ACCESS CHANNEL PROCEDURE," filed March 20, 2020, by Taherzadeh Boroujeni et al.; and U.S. Patent Application No. 17 / 204,772, entitled "FRONT-LOADED TRANSMISSION IN A RANDOM ACCESS CHANNEL PROCEDURE," filed March 17, 2021, by Taherzadeh Boroujeni et al., each of which has been assigned to the assignee of this application. Technical Field

[0003] The following content generally relates to wireless communication, and more specifically to front-loaded transmission in the random access channel process. Background Technology

[0004] Wireless communication systems are widely deployed to provide various types of communication content, such as voice, video, packet data, message sending and receiving, and broadcasting. These systems can support communication with multiple users by sharing available system resources (e.g., time, frequency, and power). Examples of such multiple access systems include fourth-generation (4G) systems, such as Long Term Evolution (LTE), LTE-A, or LTE-A Pro systems, and fifth-generation (5G) systems, which may be referred to as New Radio (NR) systems. These systems can employ technologies such as Code Division Multiple Access (CDMA), Time Division Multiple Access (TDMA), Frequency Division Multiple Access (FDMA), Orthogonal Frequency Division Multiple Access (OFDMA), or Discrete Fourier Transform Extended Orthogonal Frequency Division Multiplexing (DFT-S-OFDM). A wireless multiple access communication system may include one or more base stations or one or more network access nodes, each supporting communication for multiple communication devices simultaneously, which may be referred to as User Equipment (UE).

[0005] In some cases, a user equipment (UE) can perform a random access channel (RACH) procedure with a base station to gain access to the base station. If the UE is too far from the base station, the RACH procedure may fail. Summary of the Invention

[0006] The described techniques relate to improved methods, systems, devices, and apparatuses for supporting preload transmission during a random access channel (RACH) procedure. Typically, the described techniques provide the transmission of a reference signal and / or preamble during the RACH procedure to achieve increased beam gain and / or improved channel estimation. For example, a user equipment (UE) may transmit a first message of the RACH procedure to a base station. The UE may receive a second message of the RACH procedure from the base station based on the first message. The UE may transmit a preamble, a reference signal, or both, and a third message of the RACH procedure to the base station based on the second message.

[0007] A method for wireless communication performed by a UE is described. The method may include: transmitting a first message of a RACH procedure, receiving a second message of a RACH procedure based on the first message, and transmitting a preamble, a reference signal, or both, and a third message of the RACH procedure based on the second message.

[0008] An apparatus for wireless communication performed by a UE is described. The apparatus may include a processor, a memory in electronic communication with the processor, and instructions stored in the memory. The instructions can be executed by the processor to cause the apparatus to: transmit a first message of a RACH procedure, receive a second message of a RACH procedure based on the first message, and transmit a preamble, a reference signal, or both, and a third message of the RACH procedure based on the second message.

[0009] Another apparatus for wireless communication performed by a UE is described. The apparatus may include: components for transmitting a first message of a RACH procedure, components for receiving a second message of a RACH procedure based on the first message, and components for transmitting a preamble, a reference signal, or both, and a third message of the RACH procedure based on the second message.

[0010] A non-transitory computer-readable medium is described, storing code for wireless communication performed by a UE. The code may include instructions that can be executed by a processor to: send a first message of a RACH procedure, receive a second message of a RACH procedure based on the first message, and send a preamble, a reference signal, or both, and a third message of a RACH procedure based on the second message.

[0011] In some examples of the methods, apparatuses, and nontransitory computer-readable media described herein, transmitting a preamble, reference signal, or both may include operations, features, components, or instructions for transmitting the preamble, reference signal, or both prior to the transmission of a third message.

[0012] In some examples of the methods, apparatuses, and nontransitory computer-readable media described herein, transmitting a preamble, a reference signal, or both may include operations, features, components, or instructions for transmitting the preamble, reference signal, or both based on a reference signal receive power measurement.

[0013] Some examples of the methods, apparatuses, and nontransitory computer-readable media described herein may also include operations, features, components, or instructions for receiving control signaling that configures a UE to transmit a preamble, a reference signal, or both.

[0014] Certain examples of the methods, apparatuses, and nontransitory computer-readable media described herein may also include operations, features, components, or instructions for receiving control signaling for configuring a UE to send a first option for sending a preamble, a reference signal, or both along with a third message, and a second option for sending a third message without sending a preamble, a reference signal, or both.

[0015] In some examples of the methods, apparatuses, and nontransitory computer-readable media described herein, receiving a second message may include operations, features, components, or instructions for receiving a second message that indicates a first option to instruct the UE to send a preamble, a reference signal, or both together with a third message.

[0016] In some examples of the methods, apparatuses, and nontransitory computer-readable media described herein, receiving a second message may include operations, features, components, or instructions for receiving a second message instructing the UE to send a preamble, a reference signal, or both together with a third message.

[0017] Some examples of the methods, apparatuses, and nontransitory computer-readable media described herein may also include operations, features, components, or instructions for receiving control signaling for a UE configured to transmit a first resource therein, a preamble, a reference signal, or both, and a second resource therein, to transmit a third message.

[0018] In some examples of the methods, apparatuses, and nontransitory computer-readable media described herein, the first resource and the second resource may be sequential in time.

[0019] In some examples of the methods, apparatuses, and nontransitory computer-readable media described herein, a time period exists between the first resource and the second resource.

[0020] In some examples of the methods, apparatuses, and nontransitory computer-readable media described herein, the first resource and the second resource may be continuous in frequency.

[0021] In some examples of the methods, apparatuses, and nontransitory computer-readable media described herein, a frequency gap exists between the first resource and the second resource.

[0022] In some examples of the methods, apparatuses, and nontransitory computer-readable media described herein, transmitting a preamble, a reference signal, or both may include operations, features, components, or instructions for transmitting a preamble, a reference signal, or both based on an exposure condition being identified.

[0023] Some examples of the methods, apparatuses, and nontransitory computer-readable media described herein may also include operations, features, components, or instructions for receiving a fourth message in a RACH procedure based on a third message.

[0024] In some examples of the methods, apparatuses, and nontransitory computer-readable media described herein, the RACH process can be a four-step RACH process.

[0025] A method for wireless communication performed by a base station is described. The method may include: receiving a first message of a RACH procedure from a UE, sending a second message of the RACH procedure based on the first message, and receiving a preamble, a reference signal, or both, and a third message of the RACH procedure based on the second message.

[0026] An apparatus for wireless communication by a base station is described. The apparatus may include a processor, a memory in electronic communication with the processor, and instructions stored in the memory. The instructions can be executed by the processor to cause the apparatus to: receive a first message of a RACH procedure from a UE, send a second message of a RACH procedure based on the first message, and receive a preamble, a reference signal, or both, and a third message of a RACH procedure based on the second message.

[0027] Another apparatus for wireless communication performed by a base station is described. The apparatus may include: components for receiving a first message of a RACH procedure from a UE; components for sending a second message of the RACH procedure based on the first message; and components for receiving a preamble, a reference signal, or both, and a third message of the RACH procedure based on the second message.

[0028] A non-transitory computer-readable medium is described, storing code for wireless communication performed by a base station. The code may include instructions that can be executed by a processor to: receive a first message of a RACH procedure from a UE, send a second message of a RACH procedure based on the first message, and receive a preamble, a reference signal, or both, and a third message of a RACH procedure based on the second message.

[0029] In some examples of the methods, apparatuses, and nontransitory computer-readable media described herein, receiving a preamble, a reference signal, or both may include operations, features, components, or instructions for receiving the preamble, reference signal, or both prior to a third message.

[0030] In some examples of the methods, apparatuses, and nontransitory computer-readable media described herein, receiving a preamble, a reference signal, or both may include operations, features, components, or instructions for receiving the preamble, reference signal, or both based on a reference signal power measurement.

[0031] Some examples of the methods, apparatuses, and nontransitory computer-readable media described herein may also include operations, features, components, or instructions for transmitting control signaling that configures the UE to transmit a preamble, a reference signal, or both.

[0032] Certain examples of the methods, apparatuses, and nontransitory computer-readable media described herein may also include operations, features, components, or instructions for transmitting control signaling for configuring a UE to transmit a first option for transmitting a preamble, a reference signal, or both together with a third message, and a second option for transmitting a third message without transmitting a preamble, a reference signal, or both.

[0033] In some examples of the methods, apparatuses, and nontransitory computer-readable media described herein, transmitting a second message may include operations, features, components, or instructions for transmitting a second message that indicates a first option to instruct the UE to transmit a preamble, a reference signal, or both together with a third message.

[0034] In some examples of the methods, apparatuses, and nontransitory computer-readable media described herein, sending a second message may include operations, features, components, or instructions for sending a second message instructing the UE to send a preamble, a reference signal, or both together with a third message.

[0035] Some examples of the methods, apparatuses, and nontransitory computer-readable media described herein may also include operations, features, components, or instructions for transmitting control signaling for a UE to configure a first resource in which a preamble, a reference signal, or both are transmitted, and a second resource in which a third message is transmitted.

[0036] In some examples of the methods, apparatuses, and nontransitory computer-readable media described herein, the first resource and the second resource may be sequential in time.

[0037] In some examples of the methods, apparatuses, and nontransitory computer-readable media described herein, a time period exists between the first resource and the second resource.

[0038] In some examples of the methods, apparatuses, and nontransitory computer-readable media described herein, the first resource and the second resource may be continuous in frequency.

[0039] In some examples of the methods, apparatuses, and nontransitory computer-readable media described herein, a frequency gap exists between the first resource and the second resource.

[0040] In some examples of the methods, apparatuses, and nontransitory computer-readable media described herein, receiving a preamble, a reference signal, or both may include operations, features, components, or instructions for receiving the preamble, reference signal, or both based on an exposure condition identified.

[0041] Some examples of the methods, apparatuses, and nontransitory computer-readable media described herein may also include operations, features, components, or instructions for sending a fourth message in a RACH process based on a third message.

[0042] In some examples of the methods, apparatuses, and nontransitory computer-readable media described herein, the RACH process can be a four-step RACH process. Attached Figure Description

[0043] Figure 1 The figure illustrates an example of a wireless communication system according to aspects of this disclosure.

[0044] Figure 2 The figure illustrates an example of a wireless communication system according to aspects of this disclosure.

[0045] Figure 3 The figure illustrates an example of a random access channel (RACH) procedure according to aspects of this disclosure.

[0046] Figure 4 The diagram illustrates an example of a process flow according to an aspect of this disclosure.

[0047] Figure 5 and 6 A block diagram of an apparatus for supporting preload transmission in a random access channel process according to aspects of this disclosure is shown.

[0048] Figure 7 A block diagram of a communication manager according to aspects of this disclosure is shown.

[0049] Figure 8 A diagram of a system including devices according to aspects of this disclosure is shown.

[0050] Figure 9 and 10 A block diagram of an apparatus for supporting preload transmission in a random access channel process according to aspects of this disclosure is shown.

[0051] Figure 11 A block diagram of a communication manager according to aspects of this disclosure is shown.

[0052] Figure 12 A diagram of a system including devices according to aspects of this disclosure is shown.

[0053] Figures 13 to 17The figure shows a flowchart illustrating a method for preload transmission in a random access channel process according to aspects of this disclosure. Detailed Implementation

[0054] In some cases, the User Equipment (UE) and the base station can perform a Random Access Channel (RACH) procedure, which enables the UE to obtain access to the base station for communication. Initially, the UE may send a first message (e.g., a RACH preamble) to the base station. After receiving the first message, the base station may send a second message (e.g., a Random Access Response (RAR)) to the UE. After receiving the second message, the UE may send a third message (e.g., a Physical Uplink Shared Channel (PUSCH) transmission including a Radio Resource Control (RRC) connection request). After receiving the third message, the base station may send a fourth message to the UE (e.g., a Physical Downlink Shared Channel (PDSCH) transmission including contention resolution).

[0055] In some cases, a UE may have a limited capability to transmit third messages at a transmission power sufficient for the base station to receive them. For example, the UE may have a limited maximum transmission power relative to the base station. Thus, there may be scenarios where the UE can receive transmissions from the base station, but the base station may not be able to receive transmissions from the UE. Alternatively, due to one or more constraints, the UE may transmit at a power lower than its maximum transmission power. For example, the UE may operate according to a Maximum Permissible Exposure (MPE) limit.

[0056] Improving the channel estimation capability of a base station and / or increasing the receive beam gain at the base station can increase coverage for the UE (e.g., without increasing the transmission power of the third message). To enable the base station to have improved channel estimation and / or increased beam gain, the UE can transmit a preamble, a reference signal, or both along with the third message. The base station can use the preamble, reference signal, or both to perform channel estimation, refine the base station's receive beam, or both, which can enable the base station to have greater coverage over which the base station can receive the third message.

[0057] The aspects of this disclosure are initially described in the context of a wireless communication system. Additional aspects of this disclosure are described in the context of an additional wireless communication system, a RACH process, and process flow. The aspects of this disclosure are further illustrated and described by way of apparatus diagrams, system diagrams, and flowcharts relating to preload transmission in a random access channel process.

[0058] Figure 1The figure illustrates an example of a wireless communication system 100 according to aspects of this disclosure. The wireless communication system 100 may include one or more base stations 105, one or more UEs 115, and a core network 130. In some examples, the wireless communication system 100 may be a Long Term Evolution (LTE) network, an LTE-Advanced (LTE-A) network, an LTE-A Pro network, or a New Radio (NR) network. In some examples, the wireless communication system 100 may support enhanced broadband communication, ultra-reliable (e.g., mission-critical) communication, low latency communication, communication with low-cost and low-complexity devices, or any combination thereof.

[0059] Base stations 105 can be distributed throughout a geographic area to form a wireless communication system 100 and can be devices of different forms or with different capabilities. Base stations 105 and UE 115 can communicate wirelessly via one or more communication links 125. Each base station 105 can provide a coverage area 110, and UE 115 and base station 105 can establish one or more communication links 125 on the coverage area 110. The coverage area 110 can be an example of a geographic area on which base station 105 and UE 115 can support signal communication according to one or more radio access technologies.

[0060] UE 115 can be distributed throughout the entire coverage area 110 of the wireless communication system 100, and each UE 115 can be stationary, mobile, or both at different times. UE 115 can be devices of different forms or with different capabilities. Some example UE 115s are... Figure 1 It is shown in the middle. For example... Figure 1 As shown, the UE 115 described herein can communicate with various types of devices, such as other UE 115s, base station 105, or network equipment (e.g., core network nodes, relay equipment, integrated access and backhaul (IAB) nodes, or other network equipment).

[0061] Base station 105 may communicate with core network 130 or with each other, or both. For example, base station 105 may interface with core network 130 via one or more backhaul links 120 (e.g., via S1, N2, N3, or other interfaces). Base station 105 may communicate with each other directly (e.g., directly between base stations 105) or indirectly (e.g., via core network 130) (or both) via backhaul links 120 (e.g., via X2, Xn, or other interfaces). In some examples, backhaul link 120 may be or include one or more radio links.

[0062] One or more of the base stations 105 described herein may include, or may be referred to by those skilled in the art as, base transceiver station, radio base station, access point, radio transceiver, Node (node) B, eNodeB (eNB), next-generation NodeB or gigabit-NodeB (any of which may be referred to as gNB), home NodeB, home eNodeB or other suitable terms.

[0063] UE 115 may include or be referred to as a mobile device, wireless device, remote device, handheld device, or subscriber device, or some other suitable term, wherein "device" may also be referred to as a unit, station, terminal, or client, etc. UE 115 may also include or be referred to as a personal electronic device, such as a cellular phone, personal digital assistant (PDA), tablet computer, laptop computer, or personal computer. In some examples, UE 115 may include or be referred to as a wireless local loop (WLL) station, Internet of Things (IoT) device, Internet of Everything (IoE) device, or machine-type communication (MTC) device, etc., and may be implemented in various items, such as appliances, vehicles, instruments, etc.

[0064] like Figure 1 As shown, the UE 115 described herein can communicate with various types of devices, such as other UE 115s that can sometimes act as relays, as well as base stations 105 and network equipment including macro eNBs or gNBs, small cell eNBs or gNBs, or relay base stations.

[0065] UE 115 and base station 105 can wirelessly communicate with each other via one or more communication links 125 and one or more carriers. The term "carrier" can refer to a collection of radio frequency spectrum resources having a defined physical layer structure for supporting communication link 125. For example, a carrier for communication link 125 may include a portion (e.g., a bandwidth portion (BWP)) of a radio frequency spectrum band operating according to one or more physical layer channels for a given radio access technology (e.g., LTE, LTE-A, LTE-A Pro, NR). Each physical layer channel may carry acquisition signaling (e.g., synchronization signals, system information), control signaling coordinating the operation of the carrier, user data, or other signaling. Wireless communication system 100 can support communication with UE 115 using carrier aggregation or multi-carrier operation. Depending on the carrier aggregation configuration, UE 115 can be configured with multiple downlink component carriers and one or more uplink component carriers. Carrier aggregation can be used in conjunction with frequency division duplex (FDD) and time division duplex (TDD) component carriers.

[0066] The signal waveform transmitted via a carrier can consist of multiple subcarriers (e.g., using multi-carrier modulation (MCM) techniques, such as orthogonal frequency division multiplexing (OFDM) or discrete Fourier transform extended OFDM (DFT-S-OFDM)). In a system employing MCM, a resource element can consist of a symbol period (e.g., the duration of a modulation symbol) and a subcarrier, where the symbol period and subcarrier spacing are negatively correlated. The number of bits carried by each resource element can depend on the modulation scheme (e.g., the order of the modulation scheme, the decoding rate of the modulation scheme, or both). Therefore, the more resource elements the UE 115 receives and the higher the order of the modulation scheme, the higher the data rate that can be used for the UE 115. Wireless communication resources can refer to a combination of radio frequency spectrum resources, temporal resources, and spatial resources (e.g., spatial layers or beams), and the use of multiple spatial layers can further improve the data rate or data integrity used for communication with the UE 115.

[0067] The time interval used for base station 105 or UE 115 can be expressed as a multiple of a basic time unit, such as referring to... The sampling period is seconds, in which This can represent the maximum supported subcarrier spacing, while This can represent the maximum supported Discrete Fourier Transform (DFT) size. The time interval of the communication resource can be organized according to radio frames, each with a specified duration (e.g., 10 milliseconds (ms)). Each radio frame can be identified by a System Frame Number (SFN) (e.g., ranging from 0 to 1023).

[0068] Each frame may include multiple consecutively numbered subframes or time slots, and each subframe or time slot may have the same duration. In some examples, a frame may be divided (e.g., in the time domain) into subframes, and each subframe may be further divided into multiple time slots. Alternatively, each frame may include a variable number of time slots, and the number of time slots may depend on the subcarrier spacing. Each time slot may include multiple symbol periods (e.g., depending on the length of the cyclic prefix appended to each symbol period). In some wireless communication systems 100, time slots may be further divided into multiple micro-time slots containing one or more symbols. In addition to the cyclic prefix, each symbol period may contain one or more (e.g., The sampling period. The duration of the symbol period can depend on the subcarrier spacing or the operating frequency band.

[0069] A subframe, time slot, micro-time slot, or symbol can be the smallest scheduling unit of the wireless communication system 100 (e.g., in the time domain) and can be referred to as a transmission time interval (TTI). In some examples, the duration of the TTI (e.g., the number of symbol periods in the TTI) can be variable. Additionally or alternatively, the smallest scheduling unit of the wireless communication system 100 can be dynamically selected (e.g., in a burst of shortened TTIs (sTTIs)).

[0070] Physical channels can be multiplexed on a carrier using various techniques. For example, one or more of Time Division Multiplexing (TDM), Frequency Division Multiplexing (FDM), or hybrid TDM-FDM techniques can be used to multiplex physical control channels and physical data channels on a downlink carrier. A control region (e.g., a control resource set (CORESET)) for physical control channels can be defined by multiple symbol periods and can extend across the system bandwidth or a subset of the carrier's system bandwidth. One or more control regions (e.g., CORESET) can be configured for use by a set in UE 115. For example, one or more UE 115s can monitor or search control regions to obtain control information based on one or more search space sets, and each search space set can include one or more control channel candidates arranged in a cascaded manner in one or more aggregation levels. An aggregation level for control channel candidates can refer to the number of control channel resources (e.g., control channel elements (CCEs)) associated with coded information in a control information format having a given payload size. The search space set may include a common search space set configured to issue control information to multiple UEs 115 and a UE-specific search space set configured to issue control information to a specific UE 115.

[0071] In some examples, base station 105 may be mobile and thus provide communication coverage for mobile geographic coverage areas 110. In some examples, different geographic coverage areas 110 associated with different technologies may overlap, but different geographic coverage areas 110 may be supported by the same base station 105. In other examples, overlapping geographic coverage areas 110 associated with different technologies may be supported by different base stations 105. Wireless communication system 100 may include, for example, a heterogeneous network, in which different types of base stations 105 use the same or different radio access technologies to provide coverage for various geographic coverage areas 110.

[0072] Wireless communication system 100 can be configured to support ultra-reliable communication or low latency communication, or various combinations thereof. For example, wireless communication system 100 can be configured to support ultra-reliable low latency communication (URLLC) or mission-critical communication. UE 115 can be designed to support ultra-reliable, low latency, or mission-critical functions (e.g., mission-critical functions). Ultra-reliable communication can include private or group communication and can be supported by one or more mission-critical services, such as mission-critical key-push talk (MCPTT), mission-critical video (MCVideo), or mission-critical data (MCData). Support for mission-critical functions can include service prioritization, and mission-critical services can be used for public safety or general business applications. The terms ultra-reliable, low latency, mission-critical, and ultra-reliable low latency are used interchangeably herein.

[0073] In some examples, UE 115 may also be able to communicate directly with other UE 115 via device-to-device (D2D) communication link 135 (e.g., using peer-to-peer (P2P) or D2D protocols). One or more UE 115s utilizing D2D communication may be within the geographic coverage area 110 of base station 105. Other UE 115s in such a group may be outside the geographic coverage area 110 of base station 105, or otherwise unable to receive transmissions from base station 105. In some examples, the group of UE 115s communicating via D2D communication may utilize a one-to-many (1:M) system, where each UE 115 transmits to every other UE 115 in the group. In some examples, base station 105 facilitates the scheduling of resources for D2D communication. In other cases, D2D communication is performed between UE 115s without the involvement of base station 105.

[0074] Core network 130 can provide user authentication, access authorization, tracking, Internet Protocol (IP) connectivity, and other access, routing, or mobility functions. Core network 130 can be an evolved packet core (EPC) or a 5G core (5GC), which may include at least one control plane entity (e.g., a mobility management entity (MME), access and mobility management function (AMF)) managing access and mobility, and at least one user plane entity (e.g., a serving gateway (S-GW), packet data network (PDN) gateway (P-GW), or user plane function (UPF)) routing packets or interconnecting to external networks. The control plane entity can manage non-access stratum (NAS) functions, such as mobility, authentication, and bearer management for UE 115 served by base station 105 associated with core network 130. User IP packets can be delivered through user plane entities, which can provide IP address allocation and other functions. User plane entities can connect to network operator IP service 150. Operator IP service 150 may include access to the Internet, one or more intranets, IP Multimedia Subsystem (IMS), or packet-switched streaming services.

[0075] Some network devices (such as base station 105) may include sub-components, such as access network entity 140, which may be an example of an access node controller (ANC). Each access network entity 140 may communicate with UE 115 through one or more other access network transmitting entities 145, which may be referred to as a radio headend, smart radio headend, or transmit / receive point (TRP). Each access network transmitting entity 145 may include one or more antenna panels. In some configurations, the various functions of each access network entity 140 or base station 105 may be distributed across various network devices (e.g., radio headends and ANCs) or combined into a single network device (e.g., base station 105).

[0076] Wireless communication system 100 can operate using one or more frequency bands typically in the range of 300 MHz to 300 GHz. The region from 300 MHz to 3 GHz is generally referred to as the ultra-high frequency (UHF) region or decimeter band because the wavelength range is from approximately one decimeter to one meter. UHF waves may be blocked or redirected by buildings and environmental features, but these waves can penetrate structures sufficiently to enable macrocells to serve UE 115 located indoors. Compared to transmissions using smaller frequencies and longer waves in the high frequency (HF) or very high frequency (VHF) portions of the spectrum below 300 MHz, UHF wave transmissions can be associated with smaller antennas and shorter distances (e.g., less than 100 km).

[0077] Wireless communication system 100 can utilize both licensed and unlicensed radio frequency spectrum bands. For example, wireless communication system 100 can employ License Assisted Access (LAA), LTE-Unlicensed (LTE-U) radio access technology, or NR technology in unlicensed bands (such as the 5 GHz Industrial, Scientific, and Medical (ISM) band). When operating in unlicensed radio frequency spectrum bands, devices such as base station 105 and UE 115 can employ carrier sensing for collision detection and avoidance. In some examples, operation in unlicensed bands can be configured based on carrier aggregation along with component carriers operating in licensed bands (e.g., LAA). Among other examples, operation in unlicensed spectrum can include downlink transmission, uplink transmission, P2P transmission, or D2D transmission.

[0078] Base station 105 or UE 115 may be equipped with multiple antennas that can be used to employ techniques such as transmit diversity, receive diversity, multiple-input multiple-output (MIMO) communication, or beamforming. The antennas of base station 105 or UE 115 may be located within one or more antenna arrays or antenna panels that can support MIMO operation or transmit or receive beamforming. For example, one or more base station antennas or antenna arrays may be co-located at an antenna assembly (such as an antenna tower). In some examples, the antennas or antenna arrays associated with base station 105 may be located in different geographical locations. Base station 105 may have an antenna array with multiple rows and columns of antenna ports that base station 105 can use to support beamforming for communication with UE 115. Similarly, UE 115 may have one or more antenna arrays that can support various MIMO or beamforming operations. Additionally or alternatively, antenna panels may support radio frequency beamforming for signals transmitted via antenna ports.

[0079] Beamforming (also known as spatial filtering, directional transmission, or directional reception) is a signal processing technique that can be used at a transmitting or receiving device (e.g., base station 105, UE 115) to shape or guide an antenna beam (e.g., transmit beam, receive beam) along a spatial path between the transmitting and receiving devices. Beamforming can be achieved by combining signals communicating via antenna elements of an antenna array such that some signals propagating with respect to a specific orientation of the antenna array experience constructive interference while others experience destructive interference. Adjustments to the signals communicating via the antenna elements can include the transmitting or receiving device applying amplitude shifts, phase shifts, or both to the signals carried via the antenna elements associated with the device. The adjustments associated with each of the antenna elements can be defined by a beamforming weight set associated with a specific orientation (e.g., the antenna array relative to the transmitting or receiving device, or relative to some other orientation).

[0080] Base station 105 or UE 115 may use beam scanning technology as part of beamforming operations. For example, base station 105 may use multiple antennas or antenna arrays (e.g., antenna panels) to perform beamforming operations for directional communication with UE 115. Certain signals (e.g., synchronization signals, reference signals, beam selection signals, or other control signals) may be transmitted multiple times by base station 105 in different directions. For example, base station 105 may transmit signals according to different beamforming weight sets associated with different transmission directions. Transmissions in different beam directions may be used to identify (e.g., by transmitting devices, such as base station 105, or receiving devices, such as UE 115) the beam directions used by base station 105 for subsequent transmissions or receptions.

[0081] Certain signals, such as data signals associated with a specific receiving device, may be transmitted by base station 105 in a single beam direction (e.g., the direction associated with the receiving device, such as UE 115). In some examples, the beam direction associated with transmission along a single beam direction may be determined based on signals transmitted in one or more beam directions. For example, UE 115 may receive one or more signals transmitted by base station 105 in different directions and may report to base station 105 an indication that UE 115 received a signal with the highest signal quality or with other acceptable signal quality.

[0082] In some examples, multiple beam directions can be used to perform transmission by a device (e.g., base station 105 or UE 115), and the device can use a combination of digital precoding or radio frequency beamforming to generate a combined beam for transmission (e.g., from base station 105 to UE 115). UE 115 can report feedback indicating precoding weights for one or more beam directions, and this feedback can correspond to the number of beams configured across system bandwidth or one or more subbands. Base station 105 can transmit reference signals (e.g., cell-specific reference signals (CRS), channel state information reference signals (CSI-RS)), which can be precoded or unprecoded. UE 115 can provide feedback for beam selection, which can be a precoding matrix indicator (PMI) or codebook-based feedback (e.g., multi-panel type codebook, linear combination type codebook, port selection type codebook). Although these techniques are described with reference to signals transmitted by base station 105 in one or more directions, UE 115 may employ similar techniques to transmit signals multiple times in different directions (e.g., to identify beam directions for subsequent transmission or reception by UE 115), or to transmit signals in a single direction (e.g., to transmit data to a receiving device).

[0083] A receiving device (e.g., UE 115) may attempt multiple receiving configurations (e.g., directional listening) when receiving various signals (such as synchronization signals, reference signals, beam selection signals, or other control signals) from base station 105. For example, the receiving device may attempt multiple receiving directions by: receiving via different antenna subarrays; processing the received signal according to different antenna subarrays; receiving according to different sets of receiving beamforming weights applied to signals received at multiple antenna elements of the antenna array (e.g., different directional listening weight sets); or processing the received signal according to different sets of receiving beamforming weights applied to signals received at multiple antenna elements of the antenna array, any of which can be referred to as "listening" according to different receiving configurations or receiving directions. In some examples, the receiving device may use a single receiving configuration to receive along a single beam direction (e.g., when receiving data signals). The single receiving configuration may be aligned to a beam direction determined based on listening according to different receiving configuration directions (e.g., a beam direction determined to have the highest signal strength, highest signal-to-noise ratio (SNR), or other acceptable signal quality based on listening according to multiple beam directions).

[0084] Wireless communication systems are widely deployed to provide various types of communication content, such as voice, video, packet data, messaging, and broadcasting. These systems can be multiple access systems capable of supporting communication with multiple users by sharing available system resources (e.g., time, frequency, and power). Wireless networks, such as wireless local area networks (WLANs), and networks like Wi-Fi (i.e., IEEE 802.11), can include access points (APs) that can communicate with one or more wireless or mobile devices. APs can be coupled to a network, such as the Internet, and enable mobile devices to communicate via the network (or with other devices coupled to the access point). Wireless devices can communicate bidirectionally with network devices. For example, in a WLAN, a device can communicate with an associated AP via a downlink (e.g., a communication link from the AP to the device) and an uplink (e.g., a communication link from the device to the AP). Wireless personal area networks (PANs) (which may include Bluetooth connectivity) can provide short-range wireless connectivity between two or more paired wireless devices. For example, a wireless device (such as a cellular phone) can utilize wireless PAN communication to exchange information, such as audio signals, with a wireless headset.

[0085] Typically, techniques as described herein can provide the transmission of reference signals and / or preambles during the RACH process to achieve increased beam gain and / or improved channel estimation. For example, UE 115 can send a first message of the RACH process to base station 105. UE 115 can receive a second message of the RACH process from base station 105 based on the first message. UE 115 can then send a preamble, reference signals, or both, and a third message of the RACH process to base station 105 based on the second message.

[0086] Figure 2 The figure illustrates an example of a wireless communication system 200 according to aspects of this disclosure. In some examples, the wireless communication system 200 may implement aspects of the wireless communication system 100. For example, UE 115-a may be a reference. Figure 1 The example described is UE 115, and base station 105-a may be used as a reference. Figure 1 An example of a base station 105 is described.

[0087] In certain situations, UE 115-a and base station 105-a can perform a RACH procedure. Initially, UE 115-a can send a first message 205 (i.e., Msg1) to base station 105-a. After receiving the first message 205, base station 105-a can send a second message 210 (i.e., Msg2) to UE 115-a. After receiving the second message 210, UE 115-a can send a third message 215 (i.e., Msg3). After receiving the third message 215, base station 105-a can send a fourth message 220 (i.e., Msg4) to UE 115-a.

[0088] Performing the RACH procedure may limit the coverage of millimeter-wave (mmW) 5G devices (e.g., become a bottleneck). Coverage may be limited or affected by one or both devices using a wide broadcast synchronization block (SSB) beam for the RACH procedure. For example, a wider beam may have a lower beam gain, which may limit coverage. Additionally, coverage may be affected by UE 115-a having limited transmit power (UE 115-a can use to transmit the third message 215) (e.g., transmit power significantly less than that of base station 105-a). Another factor could be that UE 115-a may be unable to transmit at maximum power due to one or more constraints. For example, physical contact may cause UE 115-a to transmit at lower power due to MPE constraints. Thus, when transmit power is constrained, the quality of channel estimation can be a performance factor for establishing a connection between UE 115-a and / or base station 105-a. The methods described herein can increase the beam gain of the received beam of base station 105-a and / or improve the channel estimation capability of base station 105-a.

[0089] For example, such a method could involve an alternative type of Msg3 (e.g., third message 215) transmitted by UE 115-a in a four-step RACH process, which could be referred to as a preload Msg3. The preload Msg3 could include additional signaling 230 (e.g., preamble and / or reference signals) accompanying or preceding Msg3 PUSCH 225. The additional signaling 230 (e.g., preamble and / or reference signals) preceding Msg3 PUSCH 225 could be used by base station 105-a to refine the receive beam for receiving Msg3 PUSCH 225 at base station 105-a and / or improve the channel estimation for Msg3 PUSCH 225. In certain circumstances, UE 115-a may select a preload Msg3 (e.g., which includes a preamble and / or a preload reference signal) based on its SSB measurements (e.g., SSB-based reference signal received power (RSRP)) and / or its exposure conditions (e.g., its MPE conditions). For example, if UE 115-a determines that the RSRP value or other SSB measurements meet a threshold (e.g., are above the threshold), UE 115-a may transmit Msg3 without additional signaling 230. However, if UE 115-a determines that the RSRP value or other SSB measurements do not meet the threshold (e.g., are below the threshold), UE 115-a may transmit a preload Msg3. Additionally or alternatively, if UE 115-a determines that the MPE value meets a threshold (e.g., is above the threshold), UE 115-a may transmit Msg3 without additional signaling 230. However, if UE115-a determines that the MPE value does not meet the threshold (e.g., is below the threshold), then UE115-a can send the preload Msg3.

[0090] In some cases, the use of a preload Msg3 (e.g., Msg3) can be associated with the use of an alternative type of first message 205 (e.g., Msg1). UE 115-a can send Msg1 in one of a variety of formats. For example, if sending Msg3 without additional signaling 230, the format in which UE 115-a can send Msg1 can be the first format used in a standard 4-step RACH. Alternatively, if sending a preload Msg3, the format can be a second format, which includes additional fields configured to indicate to base station 105-a that UE 115-a can send a preload Msg3 or fields of Msg1.

[0091] Alternatively, base station 105-a may optionally carry Msg3 and may signal to UE 115-a via a second message 210 (e.g., Msg2) to send the carry Msg3. For example, Msg2 may instruct UE 115-a to send additional signaling 230 (e.g., a preamble, a reference signal, or both) along with Msg3. If a third message 215 includes a preamble, then the third message 215 may be referred to as the preamble carry Msg3.

[0092] In some examples, the time and frequency resources used to communicate alternative types of the third message 215 (e.g., Msg3) can be continuous. For example, for the third message 215-a, the additional signaling 230-a and Msg3 PUSCH 225-a can be continuous in both time and frequency resources. For example, the first resource can span a first transmission time interval (TTI) (e.g., symbol period, time slot, subframe), which is temporally continuous with the second resource spanning a second TTI. Additionally or alternatively, the first resource can span a first frequency range (e.g., one or more subcarriers, one or more BWPs, one or more subbands, one or more resource blocks (RBs)), which is frequency continuous with the second resource spanning a second frequency range.

[0093] Alternatively or additionally, resources may be discontinuous in at least one of time and frequency. For example, a time gap and / or frequency gap may exist between the transmission of additional signaling 230 (e.g., preamble and / or reference signal) and msg3 PUSCH 225. If a time gap exists, at least one intermediate TTI (e.g., symbol period, time slot, subframe) may exist between the first and second resources. If a frequency gap exists, a frequency span (e.g., at least one subcarrier, BWP, subband, or RB) may exist between the first and second resources. In some cases, frequency resources used for preamble and reference signals may be discontinuous. An example of discontinuous resources may be third message 215-b. In third message 215-b, additional signaling 230-b and Msg3 PUSCH 225-b may be discontinuous in time and frequency.

[0094] In some examples, the methods described herein can be associated with one or more advantages. For example, by sending additional signaling 230 (e.g., preamble and / or reference signal) along with or before Msg3 PUSCH 225, base station 105-a can be able to refine the receive beam for receiving Msg3 PUSCH 225. Additionally or alternatively, base station 105-a can be able to perform improved channel estimation for Msg3 PUSCH 225. Refining the receive beam and / or performing improved (e.g., more accurate) channel estimation can enable UE 115-a and base station 105-a to perform more efficient communication. For example, by refining the receive beam and / or performing channel estimation according to the methods described herein, base station 105-a can be able to receive and / or correctly decode Msg3 PUSCH 225 more frequently.

[0095] Figure 3 The figure illustrates an example of a RACH procedure 300 according to an aspect of this disclosure. In some examples, the RACH procedure 300 may implement an aspect of the wireless communication system 100. For example, UE 115-b may be a reference Figure 1 The example described is UE 115, and base station 105-b may be used as a reference. Figure 1 An example of a base station 105 is described.

[0096] At position 305, base station 105-b can send control signaling to UE 115-b. The control signaling can configure UE 115-b to transmit a preamble (e.g., at position 320), a reference signal (e.g., at position 325), or both. Additionally or alternatively, control signaling that may include Residual Minimum System Information (RMSI) can configure UE 115-b with a first option for transmitting the preamble, reference signal, or both along with Msg3 PUSCH (e.g., at position 330), and a second option for transmitting Msg3 PUSCH without a reference signal, preamble, or both. Additionally or alternatively, the control signaling can configure UE 115-b with a first resource for transmitting the preamble, reference signal, or both, and a second resource for transmitting Msg3 PUSCH. The first and second resources can be consecutive in time, or a time interval can exist between the first and second resources. Alternatively or concurrently, the first resource and the second resource may be continuous in frequency, or there may be a frequency gap between the first resource and the second resource.

[0097] At 310, UE 115-b may send Msg1 to base station 105-b. At 315, base station 105-b may send Msg2 to UE 115-b. In some cases, Msg2 may include an index that may indicate whether UE 115-b wants to send a reference signal (e.g., at 320) and / or a preamble (e.g., at 325) together with Msg3 PUSCH (e.g., sent at 330).

[0098] At 320, UE 115-b may send a reference signal to base station 105-b. UE 115-b may determine the reference signal to send based on RSRP or exposure conditions (e.g., MPE). At 325, UE 115-b may send a preamble to base station 105-b. UE 115-b may determine the preamble to send based on RSRP or exposure conditions (e.g., MPE conditions are identified).

[0099] At position 330, UE 115-b can send Msg3 PUSCH to base station 105-b. At position 335, base station 105-b can send Msg4 to UE 115-b. After UE 115-b receives Msg4, UE 115-b and base station 105-b may have successfully established a connection and can communicate using the established connection. Thus, UE 115-b and base station 105-b may have successfully completed the RACH procedure.

[0100] Figure 4 The figure illustrates an example of a process flow 400 according to an aspect of this disclosure. In some examples, process flow 400 may implement an aspect of wireless communication system 100. For example, UE 115-c may be a reference. Figure 1 The example described is UE 115, and base station 105-c may be used as a reference. Figure 1 An example of a base station 105 is described.

[0101] At position 405, UE 115-c can transmit control signaling. Base station 105-c can receive control signaling. The control signaling can configure UE 115-c to transmit a preamble (e.g., at position 420), a reference signal (e.g., at position 425), or both. Additionally or alternatively, the control signaling can configure UE 115-c with a first option for transmitting the preamble, reference signal, or both along with a third message (e.g., transmitted at position 430), and a second option for transmitting the third message without transmitting the preamble, reference signal, or both. In some cases, the control signaling can configure UE 115-c with a first resource in which the preamble, reference signal, or both are transmitted, and a second resource in which the third message is transmitted. The first and second resources can be consecutive in time, or there can be a time interval between the first and second resources. Additionally or alternatively, the first and second resources can be consecutive in frequency, or there can be a frequency gap between the first and second resources.

[0102] At 410, UE 115-c can send the first message of the RACH procedure (e.g., Msg1). Base station 105-c can receive the first message. In some cases, the RACH procedure can be a four-step RACH procedure.

[0103] At 415, base station 105-c can send a second message (e.g., Msg2) for the RACH procedure based on the receipt of the first message. UE 115-c can receive the second message. If control signaling indicates a first option and a second option, the second message can indicate the first option to instruct UE 115c to send a preamble, a reference signal, or both along with a third message. Additionally or alternatively, the second message can instruct UE 115-c to send a preamble, a reference signal, or both along with a third message.

[0104] At 420, UE 115-c can send a preamble based on the receipt of the second message. Base station 105-c can receive the preamble. In some cases, UE 115-c can send a preamble based on identifying exposure conditions.

[0105] At 425, UE 115-c can transmit a reference signal based on the receipt of the second message. Base station 105-c can receive the reference signal. In some cases, UE 115-c can transmit a reference signal based on identifying exposure conditions.

[0106] At 430, UE 115-c may send a third message (e.g., Msg3) for the RACH procedure based on the receipt of the second message. Base station 105-c may receive the third message. In some cases, UE 115-c may send a preamble (e.g., at 420), a reference signal (e.g., at 425), or both before sending the third message. In some cases, UE 115-c may send the preamble, reference signal, or both based on RSRP measurements.

[0107] At 435, base station 105-c can send a fourth message (e.g., Msg4) for the RACH procedure based on the received fourth message. UE 115-c can receive the fourth message.

[0108] Figure 5 A block diagram 500 of a device 505 according to an aspect of this disclosure is shown. Device 505 may be an example of an aspect of UE 115 as described herein. Device 505 may include a receiver 510, a communication manager 515, and a transmitter 520. Device 505 may also include a processor. Each of these components may communicate with each other (e.g., via one or more buses).

[0109] Receiver 510 can receive information such as packets, user data, or control information associated with various information channels (e.g., control channels, data channels, and information related to preload transmission during random access channel procedures). This information can be transmitted to other components of device 505. Receiver 510 can serve as a reference. Figure 8 Examples of aspects of the transceiver 815 described. The receiver 510 may utilize a single antenna or a collection of antennas.

[0110] Communication manager 515 can send a first message of the RACH procedure, receive a second message of the RACH procedure based on the first message, and send a preamble, a reference signal, or both, and a third message of the RACH procedure based on the second message. Communication manager 515 may be an example of an aspect of communication manager 810 described herein.

[0111] The communication manager 515 or its sub-components may be implemented in hardware, processor-executable code (e.g., software or firmware), or any combination thereof. If implemented in processor-executable code, the functionality of the communication manager 515 or its sub-components may be performed by any of the following devices designed to perform the functions described in this disclosure: a general-purpose processor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA) or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof.

[0112] The communication manager 515 or its subcomponents may be physically located in various locations, including distributed such that portions of the functionality are implemented by one or more physical components in different physical locations. In some examples, according to various aspects of this disclosure, the communication manager 515 or its subcomponents may be separate and distinct components. In some examples, according to various aspects of this disclosure, the communication manager 515 or its subcomponents may be combined with one or more other hardware components, including but not limited to input / output (I / O) components, transceivers, network servers, another computing device, one or more other components described in this disclosure, or combinations thereof.

[0113] Transmitter 520 can transmit signals generated by other components of device 505. In some examples, transmitter 520 can co-occur with receiver 510 in a transceiver module. For example, transmitter 520 can be a reference. Figure 8 Examples of aspects of the transceiver 815 are described. The transmitter 520 may utilize a single antenna or a collection of antennas.

[0114] By including or configuring the communication manager 515 according to the examples described herein, device 505 (e.g., a processor that controls or otherwise couples to receiver 510, transmitter 520, communication manager 515, or a combination thereof) can support techniques for devices communicating with device 505 to refine the receive beam for receiving a third message based on a received reference signal, a received preamble, or both. Additionally or alternatively, device 505 can support techniques for devices communicating with device 505 to perform improved (e.g., more accurate) channel estimation for the reception of the third message. Accordingly, device 505 and devices communicating with it can perform more efficient communication.

[0115] Figure 6 A block diagram 600 of device 605 according to an aspect of this disclosure is shown. Device 605 may be an example of an aspect of device 505 or UE 115 as described herein. Device 605 may include receiver 610, communication manager 615, and transmitter 620. Device 605 may also include a processor. Each of these components may communicate with each other (e.g., via one or more buses).

[0116] Receiver 610 can receive information such as packets, user data, or control information associated with various information channels (e.g., control channels, data channels, and information related to preload transmission during random access channel procedures). This information can be transmitted to other components of device 605. Receiver 610 can serve as a reference. Figure 8 Examples of aspects of the transceiver 815 described. The receiver 610 may utilize a single antenna or a collection of antennas.

[0117] Communication manager 615 may be an example of an aspect of communication manager 515 as described herein. Communication manager 615 may include UE message transmitter 620 and UE message receiver 625. Communication manager 615 may be an example of an aspect of communication manager 810 described herein.

[0118] The UE message transmitter 620 can transmit the first message of the RACH procedure. In some cases, the UE message transmitter 620 can transmit a preamble, a reference signal, or both, and a third message of the RACH procedure based on a second message received by the UE message receiver 625. The UE message receiver 625 can receive the second message of the RACH procedure based on the first message.

[0119] Transmitter 630 can transmit signals generated by other components of device 605. In some examples, transmitter 630 can co-occur with receiver 610 in a transceiver module. For example, transmitter 630 can be a reference. Figure 8 Examples of aspects of the transceiver 815 described. The transmitter 630 may utilize a single antenna or a collection of antennas.

[0120] Figure 7 A block diagram 700 of a communication manager 705 according to an aspect of this disclosure is shown. The communication manager 705 may be an example of an aspect of the communication manager 515, communication manager 615, or communication manager 810 described herein. The communication manager 705 may include a UE message transmitter 710, a UE message receiver 715, and a control signaling receiver 720. Each of these modules may communicate directly or indirectly with each other (e.g., via one or more buses).

[0121] UE message transmitter 710 can transmit the first message of the RACH procedure. In some examples, UE message transmitter 710 can transmit a preamble, a reference signal, or both, and a third message of the RACH procedure based on a second message received by UE message receiver 715. In some examples, UE message transmitter 710 can transmit the preamble, a reference signal, or both before transmitting the third message. In some examples, UE message transmitter 710 can transmit the preamble, a reference signal, or both based on a reference signal received power measurement. In some examples, UE message transmitter 710 can transmit the preamble, a reference signal, or both based on an exposure condition being identified. In some cases, the RACH procedure can be a four-step RACH procedure.

[0122] The UE message receiver 715 can receive a second message of the RACH procedure based on the first message. In some examples, the second message can indicate a first option to instruct the UE to send a preamble, a reference signal, or both along with a third message. In some examples, the second message can instruct the UE to send a preamble, a reference signal, or both along with a third message. In some examples, the UE message receiver 715 can receive a fourth message of the RACH procedure based on the third message.

[0123] The control signaling receiver 720 can receive control signaling configuring the UE to transmit a preamble, a reference signal, or both. In some examples, the control signaling receiver 720 can receive control signaling configuring the UE to transmit a first option for sending a preamble, a reference signal, or both along with a third message, and a second option to transmit the third message without transmitting a preamble, a reference signal, or both. In some examples, the control signaling receiver 720 can receive control signaling configuring the UE to transmit a first resource in which a preamble, a reference signal, or both are transmitted, and a second resource in which a third message is transmitted. In some examples, the first resource and the second resource may be temporally continuous. In some examples, there is a time interval between the first resource and the second resource. In some examples, the first resource and the second resource are frequency-continuous. In some examples, there is a frequency gap between the first resource and the second resource.

[0124] Figure 8 A diagram of a system 800 including device 805 according to aspects of this disclosure is shown. Device 805 may be an example of or include components of device 505, device 605, or UE 115 described herein. Device 805 may include components for bidirectional voice and data communication, including components for transmitting and receiving communications, including a communication manager 810, a transceiver 815, an antenna 820, a memory 825, and a processor 835. These components may communicate electronically via one or more buses (e.g., bus 840).

[0125] The communication manager 810 can send a first message of the RACH process, receive a second message of the RACH process based on the first message, and send a preamble, a reference signal, or both, and a third message of the RACH process based on the second message.

[0126] Transceiver 815 can communicate bidirectionally via one or more antennas, wired or wireless links as described above. For example, transceiver 815 can represent a wireless transceiver and can communicate bidirectionally with another wireless transceiver. Transceiver 815 may also include a modem to modulate packets and provide modulated packets to an antenna for transmission, and demodulate packets received from the antenna.

[0127] In some cases, a wireless device may include a single antenna 820. However, in other cases, a device may have more than one antenna 820, which may be able to transmit or receive multiple wireless transmissions simultaneously.

[0128] Memory 825 may include random access memory (RAM) and read-only memory (ROM). Memory 825 may store computer-readable, computer-executable code 830, which includes instructions that, when executed, cause the processor to perform the various functions described herein. In some cases, memory 825 may contain a basic input / output system (BIOS), which controls basic hardware or software operations, such as interaction with peripheral components or devices.

[0129] Code 830 may include instructions for implementing aspects of this disclosure, including instructions for supporting wireless communication. Code 830 may be stored in a non-transitory computer-readable medium, such as system memory or other types of memory. In some cases, code 830 may not be directly executable by processor 835, but may cause a computer (e.g., when compiled and executed) to perform the functions described herein.

[0130] Processor 835 may include intelligent hardware devices (e.g., general-purpose processors, DSPs, CPUs, microcontrollers, ASICs, FPGAs, programmable logic devices, discrete gate or transistor logic components, discrete hardware components, or any combination thereof). In some cases, processor 835 may be configured to use a memory controller to operate a memory array. In other cases, the memory controller may be integrated into processor 835. Processor 835 may be configured to execute computer-readable instructions stored in memory (e.g., memory 825) to cause device 805 to perform various functions (e.g., functions or tasks supporting preload transmission in a random access channel process).

[0131] By including or configuring the communication manager 810 according to the examples described herein, device 805 can support techniques for devices communicating with device 805 to refine the receive beam for receiving a third message based on a received reference signal, a received preamble, or both. Additionally or alternatively, device 805 can support techniques for devices communicating with device 805 to perform improved (e.g., more accurate) channel estimation for the reception of the third message. Accordingly, device 805 and the devices communicating with it can perform more efficient communication.

[0132] Figure 9A block diagram 900 is shown of a device 905 according to an aspect of this disclosure. Device 905 may be an example of an aspect of base station 105 as described herein. Device 905 may include a receiver 910, a communication manager 915, and a transmitter 920. Device 905 may also include a processor. Each of these components may communicate with each other (e.g., via one or more buses).

[0133] Receiver 910 can receive information such as packets, user data, or control information associated with various information channels (e.g., control channels, data channels, and information related to preload transmission during random access channel procedures). This information can be transmitted to other components of device 905. Receiver 910 can serve as a reference. Figure 12 Examples of aspects of the transceiver 1220 described. The receiver 910 may utilize a single antenna or a collection of antennas.

[0134] Communication manager 915 can receive a first message of the RACH procedure from the UE, send a second message of the RACH procedure based on the first message, and receive a preamble, a reference signal, or both, and a third message of the RACH procedure based on the second message. Communication manager 915 may be an example of an aspect of communication manager 1210 described herein.

[0135] The communication manager 915 or its sub-components may be implemented in hardware, processor-executable code (e.g., software or firmware), or any combination thereof. If implemented in processor-executable code, the functionality of the communication manager 915 or its sub-components may be performed by a general-purpose processor, DSP, application-specific integrated circuit (ASIC), FPGA or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof.

[0136] The communication manager 915 or its sub-components may be physically located in various locations, including distributed such that portions of the functionality are implemented by one or more physical components in different physical locations. In some examples, according to various aspects of this disclosure, the communication manager 915 or its sub-components may be separate and distinct components. In some examples, according to various aspects of this disclosure, the communication manager 915 or its sub-components may be combined with one or more other hardware components, including but not limited to input / output (I / O) components, transceivers, network servers, another computing device, one or more other components described in this disclosure, or combinations thereof.

[0137] Transmitter 920 can transmit signals generated by other components of device 905. In some examples, transmitter 920 can co-occur with receiver 910 in a transceiver module. For example, transmitter 920 can be a reference. Figure 12Examples of aspects of the transceiver 1220 described. The transmitter 920 may utilize a single antenna or a collection of antennas.

[0138] By including or configuring the communication manager 915 according to the examples described herein, device 905 (e.g., a processor that controls or is otherwise coupled to receiver 910, transmitter 920, communication manager 915, or a combination thereof) can support techniques for device 905 to refine the receive beam for receiving a third message based on a received reference signal, a received preamble, or both. Additionally or alternatively, device 905 can support techniques for device 905 to perform improved (e.g., more accurate) channel estimation for receiving the third message. Accordingly, device 905 can perform more efficient communication (e.g., communication with another device from which device 905 receives a preamble, a reference signal, or both).

[0139] Figure 10 A block diagram 1000 of a device 1005 according to an aspect of this disclosure is shown. Device 1005 may be an example of an aspect of device 905 or base station 105 as described herein. Device 1005 may include a receiver 1010, a communication manager 1015, and a transmitter 1030. Device 1005 may also include a processor. Each of these components may communicate with each other (e.g., via one or more buses).

[0140] Receiver 1010 can receive information such as packets, user data, or control information associated with various information channels (e.g., control channels, data channels, and information related to preload transmission during random access channel procedures). This information can be transmitted to other components of device 1005. Receiver 1010 can serve as a reference. Figure 12 Examples of aspects of the transceiver 1220 described. The receiver 1010 may utilize a single antenna or a collection of antennas.

[0141] Communication manager 1015 may be an example of an aspect of communication manager 915 as described herein. Communication manager 1015 may include base station message receiver 1020 and base station message transmitter 1025. Communication manager 1015 may be an example of an aspect of communication manager 1210 described herein.

[0142] The base station message receiver 1020 can receive the first message of the RACH procedure from the UE. In some cases, the base station message receiver 1020 can receive the preamble, reference signal, or both, and the third message of the RACH procedure based on the second message sent by the base station message transmitter 1025. The base station message transmitter 1025 can send the second message of the RACH procedure based on the first message.

[0143] Transmitter 1030 can transmit signals generated by other components of device 1005. In some examples, transmitter 1030 can co-occur with receiver 1010 in a transceiver module. For example, transmitter 1030 can be a reference. Figure 12 Examples of aspects of the transceiver 1220 described. The transmitter 1030 may utilize a single antenna or a collection of antennas.

[0144] Figure 11 A block diagram 1100 of a communication manager 1105 according to an aspect of this disclosure is shown. The communication manager 1105 may be an example of an aspect of the communication manager 915, communication manager 1015, or communication manager 1210 described herein. The communication manager 1105 may include a base station message receiver 1110, a base station message transmitter 1115, and a control signaling transmitter 1120. Each of these modules may communicate with each other directly or indirectly (e.g., via one or more buses).

[0145] Base station message receiver 1110 can receive the first message of the RACH procedure from the UE. In some examples, base station message receiver 1110 can receive a preamble, a reference signal, or both, based on a second message sent by base station message transmitter 1115, and a third message of the RACH procedure. In some examples, base station message receiver 1110 can receive the preamble, a reference signal, or both before the third message. In some examples, base station message receiver 1110 can receive the preamble, a reference signal, or both based on a reference signal received power measurement. In some examples, base station message receiver 1110 can receive the preamble, a reference signal, or both based on an exposure condition being identified. In some cases, the RACH procedure can be a four-step RACH procedure.

[0146] The base station message transmitter 1115 can send a second message for the RACH procedure based on the first message. In some examples, the second message can indicate a first option to instruct the UE to send a preamble, a reference signal, or both along with a third message. In some examples, the second message can instruct the UE to send a preamble, a reference signal, or both along with a third message. In some examples, the base station message transmitter 1115 can send a fourth message for the RACH procedure based on the third message.

[0147] The control signaling transmitter 1120 can transmit control signaling to configure the UE to transmit a preamble, a reference signal, or both. In some examples, the control signaling transmitter 1120 can transmit control signaling to configure the UE to transmit a first option for sending a preamble, a reference signal, or both along with a third message, and a second option for sending the third message without sending a preamble, a reference signal, or both. In some examples, the control signaling transmitter 1120 can transmit control signaling to configure the UE to transmit a first resource in which a preamble, a reference signal, or both are transmitted, and a second resource in which a third message is transmitted. In some examples, the first resource and the second resource can be consecutive in time. In some examples, a time period can exist between the first resource and the second resource. In some examples, the first resource and the second resource can be consecutive in frequency. In some examples, a frequency gap can exist between the first resource and the second resource.

[0148] Figure 12 A diagram of a system 1200 including device 1205 according to aspects of this disclosure is shown. Device 1205 may be an example of or include components of device 905, device 1005, or base station 105 described herein. Device 1205 may include components for bidirectional voice and data communication, including components for transmitting and receiving communications, including a communication manager 1210, a network communication manager 1215, a transceiver 1220, an antenna 1225, a memory 1230, a processor 1240, and an inter-station communication manager 1245. These components may communicate electronically via one or more buses (e.g., bus 1250).

[0149] The communication manager 1210 can receive a first message of the RACH procedure from the UE, send a second message of the RACH procedure based on the first message, and receive a preamble, a reference signal or both, and a third message of the RACH procedure based on the second message.

[0150] The network communication manager 1215 can manage communication with the core network (e.g., via one or more wired backhaul links). For example, the network communication manager 1215 can manage the delivery of data communication for client devices (such as one or more UEs 115).

[0151] Transceiver 1220 can communicate bidirectionally via one or more antennas, wired or wireless links as described above. For example, transceiver 1220 can represent a wireless transceiver and can communicate bidirectionally with another wireless transceiver. Transceiver 1220 may also include a modem to modulate packets and provide modulated packets to an antenna for transmission, and demodulate packets received from the antenna.

[0152] In some cases, a wireless device may include a single antenna 1225. However, in other cases, a device may have more than one antenna 1225, which may be able to transmit or receive multiple wireless transmissions simultaneously.

[0153] Memory 1230 may include RAM and ROM. Memory 1230 may store computer-readable, computer-executable code 1235, which includes instructions that, when executed, cause the processor to perform the various functions described herein. In some cases, memory 1230 may contain a BIOS, which controls basic hardware or software operations, such as interaction with peripheral components or devices.

[0154] Code 1235 may include instructions for implementing aspects of this disclosure, including instructions for supporting wireless communication. Code 1235 may be stored in a non-transitory computer-readable medium, such as system memory or other types of memory. In some cases, code 1235 may not be directly executable by processor 1240, but may cause the computer (e.g., when compiled and executed) to perform the functions described herein.

[0155] Processor 1240 may include intelligent hardware devices (e.g., general-purpose processors, DSPs, CPUs, microcontrollers, ASICs, FPGAs, programmable logic devices, discrete gate or transistor logic components, discrete hardware components, or any combination thereof). In some cases, processor 1240 may be configured to use a memory controller to operate a memory array. In other cases, the memory controller may be integrated into processor 1240. Processor 1240 may be configured to execute computer-readable instructions stored in memory (e.g., memory 1230) to cause device 1205 to perform various functions (e.g., functions or tasks supporting preload transmission in a random access channel process).

[0156] Inter-site communication manager 1245 can manage communication with other base stations 105 and may include a controller or scheduler for controlling communication with UEs 115 that cooperate with other base stations 105. For example, inter-site communication manager 1245 can coordinate the scheduling of transmissions to UE 115 for various interference mitigation techniques, such as beamforming or joint transmission. In some examples, inter-site communication manager 1245 may provide an X2 interface within LTE / LTE-A wireless communication network technology to provide communication between base stations 105.

[0157] By including or configuring the communication manager 1210 according to the examples described herein, device 1205 can support techniques for device 1205 to refine the receive beam for receiving a third message based on a received reference signal, a received preamble, or both. Additionally or alternatively, device 1205 can support techniques for device 1205 to perform improved (e.g., more accurate) channel estimation for receiving the third message. Accordingly, device 1205 can perform more efficient communication (e.g., communication with another device from which device 1205 receives a preamble, reference signal, or both).

[0158] Figure 13 The diagram illustrates a flowchart of method 1300 according to an aspect of this disclosure. Operation of method 1300 can be implemented by a UE 115 or its components as described herein. For example, operation of method 1300 can be implemented by, as referenced... Figures 5 to 8 The described communication manager is used to execute this. In some examples, the UE can execute a set of instructions to control the functional elements of the UE to perform the described functions. Additionally or alternatively, the UE can use dedicated hardware to perform aspects of the described functions.

[0159] At step 1305, the UE can send the first message of the RACH procedure. The operation at step 1305 can be performed according to the methods described herein. In some examples, aspects of the operation at step 1305 can be derived from, as referenced... Figures 5 to 8 The UE message sender described is used to perform this.

[0160] At 1310, the UE can receive the second message of the RACH procedure based on the first message. The operation at 1310 can be performed according to the method described herein. In some examples, aspects of the operation at 1310 can be derived from, as referenced... Figures 5 to 8 The UE message receiver is described and executed.

[0161] At 1315, the UE may send a preamble, a reference signal, or both based on the second message, and a third message for the RACH procedure. The operation at 1315 can be performed according to the methods described herein. In some examples, aspects of the operation at 1315 may be determined by, as in the reference signal... Figures 5 to 8 The UE message sender described is used to perform this.

[0162] Figure 14 The diagram illustrates a flowchart of method 1400 according to an aspect of this disclosure. Operation of method 1400 can be implemented by a UE 115 or its components as described herein. For example, operation of method 1400 can be implemented by, as referenced... Figures 5 to 8The described communication manager is used to execute this. In some examples, the UE can execute a set of instructions to control the functional elements of the UE to perform the described functions. Additionally or alternatively, the UE can use dedicated hardware to perform aspects of the described functions.

[0163] At step 1405, the UE may send the first message of the RACH procedure. The operation at step 1405 can be performed according to the methods described herein. In some examples, aspects of the operation at step 1405 may be derived from, as referenced... Figures 5 to 8 The UE message sender described is used to perform this.

[0164] At point 1410, the UE can receive the second message of the RACH procedure based on the first message. The operation at point 1410 can be performed according to the method described herein. In some examples, aspects of the operation at point 1410 can be derived from, as referenced... Figures 5 to 8 The UE message receiver is described and executed.

[0165] At point 1415, the UE may send a preamble, a reference signal, or both based on the second message, and a third message for the RACH procedure, wherein the preamble, reference signal, or both are sent before the transmission of the third message. The operation at point 1415 can be performed according to the methods described herein. In some examples, aspects of the operation at point 1415 may be determined by, as in the reference... Figures 5 to 8 The UE message sender described is used to perform this.

[0166] Figure 15 The diagram illustrates a flowchart of method 1500 according to an aspect of this disclosure. Operation of method 1500 can be implemented by a UE 115 or its components as described herein. For example, operation of method 1500 can be implemented by, as referenced... Figures 5 to 8 The described communication manager is used to execute this. In some examples, the UE can execute a set of instructions to control the functional elements of the UE to perform the described functions. Additionally or alternatively, the UE can use dedicated hardware to perform aspects of the described functions.

[0167] At point 1505, the UE may receive control signaling configuring the UE to transmit a preamble, a reference signal, or both. The operation of point 1505 can be performed according to the methods described herein. In some examples, aspects of the operation of point 1505 may be determined by, as in the reference... Figures 5 to 8 The control signaling receiver described is used to execute the command.

[0168] At point 1510, the UE can send the first message of the RACH procedure. The operation at point 1510 can be performed according to the method described herein. In some examples, aspects of the operation at point 1510 can be derived from, as referenced... Figures 5 to 8 The UE message sender described is used to perform this.

[0169] At point 1515, the UE can receive the second message of the RACH procedure based on the first message. The operation at point 1515 can be performed according to the methods described herein. In some examples, aspects of the operation at point 1515 can be derived from, as referenced... Figures 5 to 8 The UE message receiver is described and executed.

[0170] At 1520, the UE may send a preamble, a reference signal, or both based on the second message, and a third message for the RACH procedure. The operation at 1520 can be performed according to the methods described herein. In some examples, aspects of the operation at 1520 may be determined by, as in the reference... Figures 5 to 8 The UE message sender described is used to perform this.

[0171] Figure 16 The diagram illustrates a flowchart of method 1600 according to an aspect of this disclosure. Operation of method 1600 can be implemented by a UE 115 or its components as described herein. For example, operation of method 1600 can be implemented by, as referenced... Figures 5 to 8 The described communication manager is used to execute this. In some examples, the UE can execute a set of instructions to control the functional elements of the UE to perform the described functions. Additionally or alternatively, the UE can use dedicated hardware to perform aspects of the described functions.

[0172] At 1605, the UE may receive control signaling configuring a first option for the UE to send a preamble, a reference signal, or both along with a third message, and a second option for sending the third message without sending the preamble, reference signal, or both. The operation of 1605 can be performed according to the methods described herein. In some examples, aspects of the operation of 1605 may be determined by, as referenced... Figures 5 to 8 The control signaling receiver described is used to execute the command.

[0173] At point 1610, the UE can send the first message of the RACH procedure. The operation at point 1610 can be performed according to the method described herein. In some examples, aspects of the operation at point 1610 can be derived from, as referenced... Figures 5 to 8 The UE message sender described is used to perform this.

[0174] At point 1615, the UE can receive the second message of the RACH procedure based on the first message. The operation at point 1615 can be performed according to the method described herein. In some examples, aspects of the operation at point 1615 can be derived from, as referenced... Figures 5 to 8 The UE message receiver is described and executed.

[0175] At 1620, the UE may send a preamble, a reference signal, or both based on the second message, and a third message for the RACH procedure. The operation at 1620 can be performed according to the methods described herein. In some examples, aspects of the operation at 1620 may be determined by, as in the reference... Figures 5 to 8 The UE message sender described is used to perform this.

[0176] Figure 17 The diagram illustrates a flowchart of method 1700 according to an aspect of this disclosure. Operation of method 1700 can be implemented by base station 105 or its components as described herein. For example, operation of method 1700 can be implemented by [reference needed]. Figures 9 to 12 The described communication manager is used to execute this. In some examples, the base station may execute a set of instructions to control the functional elements of the base station to perform the described functions. Additionally or alternatively, the base station may use dedicated hardware to perform aspects of the described functions.

[0177] At point 1705, the base station can receive the first message of the RACH procedure from the UE. The operation at point 1705 can be performed according to the method described herein. In some examples, aspects of the operation at point 1705 may be derived from, as referenced... Figures 9 to 12 The base station message receiver is described and executed.

[0178] At point 1710, the base station can send a second message of the RACH procedure based on the first message. The operation at point 1710 can be performed according to the method described herein. In some examples, aspects of the operation at point 1710 can be derived from, as referenced... Figures 9 to 12 The base station message sender described is used to perform this.

[0179] At point 1715, the base station can receive a preamble, a reference signal, or both based on a second message, and a third message of the RACH procedure. The operation at point 1715 can be performed according to the method described herein. In some examples, aspects of the operation at point 1715 can be determined by, as in the reference... Figures 9 to 12 The base station message receiver is described and executed.

[0180] It should be noted that the methods described in this paper describe possible implementations, and the operations and steps can be rearranged or otherwise modified, and other implementations are also possible. Furthermore, two or more aspects from the methods can be combined.

[0181] The following provides an overview of aspects of this disclosure:

[0182] Aspect 1: A method for wireless communication performed by a UE, comprising: transmitting a first message of a RACH procedure; receiving a second message of a RACH procedure based at least in part on the first message; and transmitting a preamble, a reference signal, or both, and a third message of the RACH procedure based at least in part on the second message.

[0183] Aspect 2: The method of aspect 1, wherein sending a preamble, a reference signal, or both includes sending a preamble, a reference signal, or both before sending a third message.

[0184] Aspect 3: The method of any one of Aspects 1 to 2, wherein transmitting a preamble, a reference signal, or both comprises: transmitting the preamble, the reference signal, or both based at least in part on a reference signal received power measurement.

[0185] Aspect 4: The method of any one of Aspects 1 to 3 further includes: receiving control signaling that configures the UE to transmit a preamble, a reference signal, or both.

[0186] Aspect 5: The method of any one of Aspects 1 to 4 further includes: receiving control signaling to configure the UE to send a first option for sending a preamble, a reference signal, or both together with a third message, and a second option for sending the third message without sending the preamble, the reference signal, or both.

[0187] Aspect 6: The method of aspect 5, wherein receiving the second message includes: receiving a second message indicating a first option to instruct the UE to send a preamble, a reference signal, or both together with a third message.

[0188] Aspect 7: The method of any one of Aspects 1 to 6, wherein receiving the second message includes: receiving a second message instructing the UE to send a preamble, a reference signal, or both together with a third message.

[0189] Aspect 8: The method of any one of Aspects 1 to 7 further includes: receiving control signaling for a first resource configured for the UE to transmit a preamble, a reference signal, or both, and a second resource configured to transmit a third message therein.

[0190] Aspect 9: The method of aspect 8, wherein the first resource and the second resource are sequential in time.

[0191] Aspect 10: The method of any of Aspects 8 to 9, wherein there is a time interval between the first resource and the second resource.

[0192] Aspect 11: The method of any one of Aspects 8 to 10, wherein the first resource and the second resource are continuous in frequency.

[0193] Aspect 12: The method of any one of Aspects 8 to 11, wherein there is a frequency gap between the first resource and the second resource.

[0194] Aspect 13: The method of any one of Aspects 1 to 12, wherein sending a preamble, a reference signal, or both comprises: sending the preamble, the reference signal, or both based at least in part on the exposure condition being identified.

[0195] Aspect 14: The method of any one of Aspects 1 to 13 further includes: receiving a fourth message of the RACH procedure at least in part based on the third message.

[0196] Aspect 15: The method of any of Aspects 1 to 14, wherein the RACH process is a four-step RACH process.

[0197] Aspect 16: A method for wireless communication performed by a base station, comprising: receiving a first message of a RACH procedure from a UE; transmitting a second message of the RACH procedure based at least in part on the first message; and receiving a preamble, a reference signal, or both, and a third message of the RACH procedure based at least in part on the second message.

[0198] Aspect 17: The method of aspect 16, wherein receiving a preamble, a reference signal, or both includes receiving a preamble, a reference signal, or both before a third message.

[0199] Aspect 18: The method of any one of Aspects 16 to 17, wherein receiving a preamble, a reference signal, or both comprises: receiving the preamble, the reference signal, or both based at least in part on a power measurement of the reference signal.

[0200] Aspect 19: The method of any one of Aspects 16 to 18 further includes: sending control signaling that configures the UE to send a preamble, a reference signal, or both.

[0201] Aspect 20: The method of any one of Aspects 16 to 19 further includes: transmitting control signaling to configure the UE to transmit a first option for transmitting a preamble, a reference signal, or both together with a third message, and a second option for transmitting the third message without transmitting the preamble, the reference signal, or both.

[0202] Aspect 21: The method of aspect 20, wherein sending the second message includes: sending a second message indicating a first option to instruct the UE to send a preamble, a reference signal, or both together with a third message.

[0203] Aspect 22: The method of any one of Aspects 16 to 21, wherein sending the second message includes: sending a second message instructing the UE to send a preamble, a reference signal, or both together with the third message.

[0204] Aspect 23: The method of any one of Aspects 16 to 22 further includes: transmitting control signaling for configuring a first resource in which the UE transmits a preamble, a reference signal, or both, and a second resource in which a third message is transmitted.

[0205] Aspect 24: The method of aspect 23, wherein the first resource and the second resource are sequential in time.

[0206] Aspect 25: The method of any of Aspects 23 to 24, wherein there is a time interval between the first resource and the second resource.

[0207] Aspect 26: The method of any one of Aspects 23 to 25, wherein the first resource and the second resource are continuous in frequency.

[0208] Aspect 27: The method of any one of Aspects 23 to 26, wherein there is a frequency gap between the first resource and the second resource.

[0209] Aspect 28: The method of any one of Aspects 16 to 27, wherein receiving a preamble, a reference signal, or both comprises: receiving the preamble, the reference signal, or both based at least in part on an exposure condition identified.

[0210] Aspect 29: The method of any one of Aspects 16 to 28 further includes: sending a fourth message of the RACH procedure based at least in part on the third message.

[0211] Aspect 30: The method of any of Aspects 16 to 29, wherein the RACH process is a four-step RACH process.

[0212] Aspect 31: An apparatus for wireless communication performed by a UE, comprising a processor; a memory coupled to the processor; and instructions stored in the memory and executable by the processor to cause the apparatus to perform the method of any one of Aspects 1 to 15.

[0213] Aspect 32: An apparatus for wireless communication performed by a UE, comprising at least one component for performing the method of any one of aspects 1 to 15.

[0214] Aspect 33: A non-transitory computer-readable medium storing code for wireless communication performed by a UE, the code including instructions executable by a processor to perform the methods of any one of Aspects 1 to 15.

[0215] Aspect 34: An apparatus for wireless communication by a base station, comprising a processor; a memory coupled to the processor; and instructions stored in the memory and executable by the processor to cause the apparatus to perform the methods of any one of Aspects 16 to 30.

[0216] Aspect 35: An apparatus for wireless communication by a base station, comprising at least one component for performing the method of any one of aspects 16 to 30.

[0217] Aspect 36: A non-transitory computer-readable medium storing code for wireless communication by a base station, the code including instructions executable by a processor to perform the methods of any one of Aspects 16 to 30.

[0218] While aspects of LTE, LTE-A, LTE-A Pro, or NR systems may be described for illustrative purposes, and the terms LTE, LTE-A, LTE-A Pro, or NR may be used in most of the description, the techniques described herein are also applicable beyond LTE, LTE-A, LTE-A Pro, or NR networks. For example, the techniques described may be applicable to a variety of other wireless communication systems, such as Ultra Mobile Broadband (UMB), IEEE 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802.20, Flash-OFDM, and other systems and radio technologies not explicitly mentioned herein.

[0219] The information and signals described herein can be represented using any of one or more different techniques. For example, data, instructions, commands, information, signals, bits, symbols, and chips that may be referenced throughout the description can be represented by voltage, current, electromagnetic waves, magnetic fields or particles, light fields or particles, or any combination thereof.

[0220] The various illustrative blocks and components described herein can be implemented or performed using any of the following devices designed to perform the functions described herein: a general-purpose processor, a DSP, an ASIC, a CPU, an FPGA or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof. A general-purpose processor may be a microprocessor, but alternatively, it may be any processor, controller, microcontroller, or state machine. A processor may also be implemented as a combination of computing devices (e.g., a combination of a DSP and a microprocessor, multiple microprocessors, one or more microprocessors associated with a DSP core, or any other such configuration).

[0221] The functions described herein can be implemented in hardware, software executed by a processor, firmware, or any combination thereof. If implemented in software executed by a processor, the functions can be stored or transmitted as one or more instructions or code on a computer-readable medium. Other examples and implementations are within the scope of this disclosure and the appended claims. For example, due to the nature of software, the functions described herein can be implemented using software executed by a processor, hardware, firmware, hardwired, or any combination thereof. Features implementing the functions can also be physically located in different places, including being distributed such that portions of the functions are implemented in different physical locations.

[0222] Computer-readable media include both non-transitory computer storage media and communication media, with communication media encompassing any medium that facilitates the transfer of a computer program from one place to another. Non-transitory storage media can be any available medium accessible by a general-purpose or special-purpose computer. By way of example, and not limitation, non-transitory computer-readable media can include RAM, ROM, electrically erasable programmable ROM (EEPROM), flash memory, compact disc (CD) ROM or other optical disc storage, disk storage or other magnetic storage devices, or any other non-transitory medium that can be used to carry or store required program code components in the form of instructions or data structures and is accessible by a general-purpose or special-purpose computer or a general-purpose or special-purpose processor. Similarly, any connection is appropriately referred to as computer-readable media. For example, if software is transmitted from a website, server, or other remote source using coaxial cable, fiber optic cable, twisted pair, digital subscriber line (DSL), or wireless technology (such as infrared, radio, and microwave), then coaxial cable, fiber optic cable, twisted pair, DSL, or wireless technology (such as infrared, radio, and microwave) is included in the definition of computer-readable media. The disks and optical discs used in this article include CDs, laser discs, optical discs, DVDs, floppy disks, and Blu-ray discs, where disks typically reproduce data magnetically, while optical discs reproduce data optically using lasers. Combinations of the above are also included within the scope of computer-readable media.

[0223] As used herein, the "or" included in the claims for a list of items (e.g., a list of items beginning with phrases such as "at least one of..." or "one or more of...") indicates an inclusive list, such that, for example, a list of at least one of A, B, or C means A or B or C or AB or AC or BC or ABC (i.e., A and B and C). Similarly, as used herein, the phrase "based on" should not be construed as a reference to a closed set of conditions. For example, an exemplary step described as "based on condition A" may be based on both condition A and condition B without departing from the scope of this disclosure. In other words, as used herein, the phrase "based on" should be interpreted in the same manner as the phrase "at least partially based on".

[0224] In the accompanying drawings, similar components or features may have the same reference numerals. Furthermore, various components of the same type can be distinguished by adding a dash after the reference numeral and a second reference numeral to differentiate between similar components. If only the first reference numeral is used in the specification, the description applies to any of the similar components having the same first reference numeral, regardless of the second or other subsequent reference numerals.

[0225] The description herein, in conjunction with the accompanying drawings, illustrates exemplary configurations and does not represent all examples that can be implemented or that fall within the scope of the claims. The term "example" as used herein means "serving as an example, instance, or illustration," not "preferred" or "superior to other examples." The detailed description includes specific details intended to provide an understanding of the described techniques. However, these techniques can be practiced without these specific details. In some instances, known structures and devices are shown in block diagram form to avoid obscuring the concepts of the described examples.

[0226] The description provided herein is intended to enable those skilled in the art to make or use this disclosure. Various modifications to this disclosure will be apparent to those skilled in the art, and the general principles defined herein can be applied to other variations without departing from the scope of this disclosure. Therefore, this disclosure is not limited to the examples and designs described herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for wireless communication performed by a user equipment (UE), comprising: Send the first message of the RACH (Random Access Channel) procedure; The second message of the RACH procedure is received at least in part based on the first message; as well as A preamble for the third message is sent before the UE sends the third message of the RACH procedure, wherein the preamble is associated with receive beam refinement for receiving the third message by the network device, and the transmission of the preamble is based at least in part on the received second message and at least one of (i) the maximum permissible exposure MPE is below a first threshold, or (ii) the reference signal measurement is below a second threshold.

2. The method as described in claim 1, wherein, Sending the preamble includes: The preamble is sent after the second message is received.

3. The method as described in claim 1, wherein, The reference signal measurement includes the reference signal received power measurement.

4. The method of claim 1, further comprising: Receive control signaling that configures the UE to send the preamble.

5. The method of claim 1, further comprising: The system receives control signaling to configure the UE with a first option for sending the preamble along with the third message, and a second option for sending the third message without sending the preamble.

6. The method of claim 5, wherein, Receiving the second message includes: The second message, which indicates the first option, instructs the UE to send the preamble along with the third message.

7. The method of claim 1, wherein, Receiving the second message includes: The UE receives the second message, which instructs it to send the preamble along with the third message.

8. The method of claim 1, further comprising: The system receives control signaling for a first resource configured for the UE to transmit the preamble, and a second resource configured to transmit the third message.

9. The method of claim 8, wherein, The first resource and the second resource are sequential in time.

10. The method of claim 8, wherein, There is a time interval between the first resource and the second resource.

11. The method of claim 8, wherein, The first resource and the second resource are continuous in frequency.

12. The method of claim 8, wherein, There is a frequency gap between the first resource and the second resource.

13. The method of claim 1, wherein, Sending the preamble includes: The preamble is sent at least in part based on the exposure conditions identified.

14. A method for wireless communication performed by a network device, comprising: Receive the first message of the Random Access Channel (RACH) procedure from the User Equipment (UE); The second message of the RACH procedure is sent at least in part based on the first message; A preamble for the third message is received prior to receiving the third message in the RACH procedure, wherein the preamble is associated with receive beam refinement for receiving the third message by the network device, and the reception of the preamble is based at least in part on the transmitted second message, and at least one of (i) the maximum permissible exposure MPE is below a first threshold, or (ii) the reference signal measurement is below a second threshold; and The receive beam refinement is performed at least in part based on the preamble.

15. The method of claim 14, wherein, Receiving the preamble includes: The preamble is received after the second message is sent.

16. The method of claim 14, wherein, The reference signal measurement includes the reference signal received power measurement.

17. The method of claim 14, further comprising: Send control signaling to configure the UE to send the preamble.

18. The method of claim 14, further comprising: Send control signaling to configure the UE with a first option to send the preamble along with the third message, and a second option to send the third message without sending the preamble.

19. The method of claim 18, wherein, Sending the second message includes: Send the second message indicating the first option to instruct the UE to send the preamble along with the third message.

20. The method of claim 14, wherein, Sending the second message includes: Send the second message, which instructs the UE to send the preamble together with the third message.

21. The method of claim 14, further comprising: Control signaling is sent to configure the UE to transmit the first resource in which the preamble is transmitted, and the second resource in which the third message is transmitted.

22. The method of claim 21, wherein, The first resource and the second resource are sequential in time.

23. The method of claim 21, wherein, There is a time interval between the first resource and the second resource.

24. The method of claim 21, wherein, The first resource and the second resource are continuous in frequency.

25. The method of claim 21, wherein, There is a frequency gap between the first resource and the second resource.

26. The method of claim 14, wherein, Receiving the preamble includes: The preamble is received at least in part based on the exposure conditions identified.

27. An apparatus for wireless communication performed by a user equipment (UE), comprising: The component used to send the first message of the RACH procedure in the random access channel; A component for receiving a second message of the RACH procedure based at least in part on the first message; as well as A component for transmitting a preamble for the third message before the UE transmits the third message of the RACH procedure, wherein the preamble is associated with receive beam refinement for receiving the third message by the network device, the transmission of the preamble being at least partially based on the received second message, and at least one of (i) the maximum permissible exposure MPE being below a first threshold, or (ii) the reference signal measurement being below a second threshold.

28. The apparatus of claim 27, further comprising: A component for sending the preamble after receiving the second message.

29. An apparatus for wireless communication performed by a network device, comprising: A component used to receive the first message of the Random Access Channel (RACH) procedure from a User Equipment (UE); A component for sending a second message of the RACH procedure based at least in part on the first message; Components for receiving a preamble for a third message prior to receiving the third message in the RACH procedure, wherein the preamble is associated with receive beam refinement for receiving the third message by the network device, the reception of the preamble being at least partially based on a second message transmitted, and at least one of (i) a maximum permissible exposure MPE below a first threshold, or (ii) a reference signal measurement below a second threshold; and The receive beam refinement is performed at least in part based on the preamble.

30. The apparatus of claim 29, further comprising: A component for receiving the preamble after the second message has been sent.

31. An apparatus for wireless communication performed by a user equipment (UE), comprising: At least one memory, wherein the at least one memory stores instructions; as well as At least one processor, the at least one processor being configured to execute the instructions to cause the apparatus to perform the method according to any one of claims 1 to 13.

32. An apparatus for wireless communication via a network device, comprising: At least one memory, wherein the at least one memory stores instructions; as well as At least one processor, the at least one processor being configured to execute the instructions to cause the apparatus to perform the method according to any one of claims 14 to 26.

33. A computer-readable medium having program code recorded thereon, wherein, The program code may be executed by one or more processors of the user equipment (UE) to cause the processors to perform the method according to any one of claims 1 to 13.

34. A computer-readable medium having program code recorded thereon, wherein, The program code may be executed by one or more processors of the network device to cause the processors to perform the method according to any one of claims 14 to 26.

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