UE to UE relay link establishment

Abstract

Methods, systems, and devices for wireless communications are described. In general, the described techniques provide for a base station to send a relay link beam scanning configuration to a first UE to establish a relay link with a second UE. Based on the relay link beam scanning configuration, the first UE may perform a relay link beam scanning procedure with the second UE using a plurality of beams. Based at least in part on the relay link beam scanning procedure, the first UE may select a first beam pair. The first UE may establish a relay link with the second UE using the selected beam pair.

Description

[0001] Cross-references

[0002] This patent application claims priority to U.S. patent application No. 16 / 866,464, filed by RAGHAVAN et al. on May 4, 2020, entitled “ESTABLISHMENT OF A UE TO UE RELAY LINK,” which claims the benefit of U.S. Provisional Patent Application No. 62 / 844,367, filed by RAGHAVAN et al. on May 7, 2019, entitled “ESTABLISHMENT OF A UETO UERELAY LINK,” which has been assigned to the assignee of the present invention. Technical Field

[0003] The present invention relates generally to wireless communications and, more particularly, to establishment of UE-to-UE relay links.

[0004] Wireless communication systems are widely deployed to provide various types of communication content, such as voice, video, packet data, message transceiving, broadcasting, etc. 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) systems, advanced LTE (LTE-A) systems or LTE-A Pro systems, and fifth generation (5G) systems that may be referred to as new radio (NR) systems. These systems may use techniques 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 multiple base stations or network access nodes, each of which simultaneously supports communication for multiple communication devices, which may be referred to as user equipment (UE).

[0005] A wireless communication system may include UEs that are capable of communicating directly with other UEs. In some cases, a first UE may operate as a relay between a base station and a second UE. In a downlink scenario, the first UE may receive a signal from a base station and forward or retransmit the received signal to a second UE. In an uplink scenario, the first UE may receive a signal from a second UE and forward or retransmit the received signal to a base station. In some wireless communication systems, various devices (e.g., UEs and base stations) may implement beamforming to improve signal transmission and reception quality. Effective techniques for performing beam coordination for establishing a relay link may improve network and device efficiency. Summary of the invention

[0006] The described technology relates to improved methods, systems, devices and apparatuses for supporting the establishment of a UE-to-UE relay link. In some cases, the technology supports the establishment of a UE-to-UE relay link on a millimeter wave carrier frequency. In general, the described technology provides a base station sending a relay link beam scanning configuration to a first UE to establish a relay link with a second UE. Based on the relay link beam scanning configuration, the first UE can use multiple beams to perform a relay link beam scanning process with the second UE. Based on the relay link beam scanning process, the first UE can select a first beam pair. The first UE can use the selected beam pair to establish a relay link with the second UE.

[0007] A method for wireless communication by a first UE is described. The method may include: receiving a relay link beam scanning configuration from a base station to establish a relay link with a second UE; performing a relay link beam scanning process with the second UE using a beam set based on the relay link beam scanning configuration; selecting a first beam pair based on the relay link beam scanning process; and establishing a relay link with the second UE using the first beam pair.

[0008] An apparatus for wireless communication by a first 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 may be executable by the processor to cause the apparatus to receive a relay link beam scanning configuration from a base station to establish a relay link with a second UE; perform a relay link beam scanning procedure with the second UE using a beam set based on the relay link beam scanning configuration; select a first beam pair based on the relay link beam scanning procedure; and establish a relay link with the second UE using the first beam pair.

[0009] Another apparatus for wireless communication by a first UE is described. The apparatus may include the following components: a component for receiving a relay link beam scanning configuration from a base station to establish a relay link with a second UE; a component for performing a relay link beam scanning process with the second UE using a beam set based on the relay link beam scanning configuration; a component for selecting a first beam pair based on the relay link beam scanning process; and a component for establishing a relay link with the second UE using the first beam pair.

[0010] A non-transitory computer-readable medium storing code for wireless communication by a first UE is described. The code may include instructions executable by a processor to receive a relay link beam scanning configuration from a base station to establish a relay link with a second UE; perform a relay link beam scanning process with the second UE using a beam set based on the relay link beam scanning configuration; select a first beam pair based on the relay link beam scanning process; and establish a relay link with the second UE using the first beam pair.

[0011] In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, receiving a relay link beam scanning configuration may include operations, features, components, or instructions for receiving a relay link beam scanning configuration indicating transmit beam scanning timing parameters for a first UE, wherein the relay link beam scanning process may be performed within a first transmit beam scanning timing corresponding to the transmit beam scanning timing parameters.

[0012] In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, performing a relay link beam scanning process may include operations, features, components, or instructions for transmitting a reference signal using a first subset of a beam set in a first transmit beam scanning opportunity and a second subset of a beam set in a second transmit beam scanning opportunity corresponding to transmit beam scanning opportunity parameters.

[0013] In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, receiving a relay link beam scanning configuration may include operations, features, components, or instructions for receiving a relay link beam scanning configuration indicating a receive beam scanning timing for a first UE, wherein the relay link beam scanning process may be performed within a first receive beam scanning timing corresponding to the receive beam scanning timing parameters.

[0014] In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, performing a relay link beam scanning process may include operations, features, components, or instructions for monitoring a reference signal sent by a second UE using a first subset of a beam set in a first receive beam scanning opportunity and a second subset of a beam set in a second receive beam scanning opportunity corresponding to receive beam scanning opportunity parameters.

[0015] In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, establishing a relay link with a second UE may include operations, features, components, or instructions for sending a random access channel message to the second UE using a transmit beam of a first beam pair at a first UE, and receiving a random access channel response from the second UE using a receive beam of the first beam pair at the first UE.

[0016] In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, performing a relay link beam scanning process may include operations, features, components, or instructions for generating measurements of each beam pair in a set of beam pairs based on cycling through the set of beam pairs.

[0017] Some examples of the methods, apparatus, and non-transitory computer-readable media described herein may also include operations, features, components, or instructions for selecting a first beam pair based on the measurement.

[0018] Some examples of the methods, apparatus, and non-transitory computer-readable media described herein may also include operations, features, components, or instructions for sending a measurement report including one or more measurements to a base station, where a relay link can be established based on receiving an instruction from the base station to establish a relay link using a first beam pair.

[0019] In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, performing a relay link beam scanning process may include operations, features, components, or instructions for sending or monitoring a reference signal generated based on a synchronization signal sequence.

[0020] In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, performing a relay link beam scanning process may include operations, features, components, or instructions for receiving a reference signal, decoding a synchronization signal sequence from the reference signal, and determining a timing offset based on the synchronization signal sequence, wherein a relay link may be established based on the timing offset.

[0021] In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, establishing a relay link with a second UE may include operations, features, components, or instructions for sending a random access request to the second UE in a random access opportunity and receiving a random access response from the second UE based on the random access request.

[0022] In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, establishing a relay link with a second UE may include operations, features, components, or instructions for receiving a random access request from the second UE in a first random access opportunity or in a second random access opportunity occurring after the first random access opportunity, and sending a random access response to the first UE based on the random access request.

[0023] Some examples of the methods, apparatus, and non-transitory computer-readable media described herein may also include operations, features, components, or instructions for sending an identifier of the second UE, beam pair information of the first beam pair, or both to the base station.

[0024] In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, receiving a relay link beam scanning configuration may include operations, features, components, or instructions for receiving a relay link beam scanning configuration indicating periodic resources in which to perform a relay link beam scanning process.

[0025] In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, the periodic resource may be a configured synchronization signal block resource, or may be different from a configured synchronization signal block resource.

[0026] In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, receiving a relay link beam scanning configuration may include operations, features, components, or instructions for receiving a relay link beam scanning configuration, wherein the relay link beam scanning configuration instructs a first set of UEs including a first UE to perform a transmit beam scanning process in a first instance of a periodic resource, and a second set of UEs including a second UE to perform a receive beam scanning process in the first instance of a periodic resource.

[0027] In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, receiving a relay link beam scanning configuration may include operations, features, components, or instructions for receiving a relay link beam scanning configuration, wherein the relay link beam scanning configuration instructs a first set of UEs including a first UE to perform a receive beam scanning process in a first instance of a periodic resource, and a second set of UEs including a second UE to perform a transmit beam scanning process in a first instance of a periodic resource.

[0028] Some examples of the methods, apparatus, and non-transitory computer-readable media described herein may also include operations, features, components, or instructions for determining to perform a relay link beam scanning procedure based on at least one parameter.

[0029] In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, the at least one parameter may be one or more of a network identifier, a cell identifier, a radio network temporary identifier, a temporary mobile subscriber identity, a temporary identifier, or any combination thereof.

[0030] Some examples of the methods, apparatus, and non-transitory computer-readable media described herein may also include operations, features, components, or instructions for detecting that each beam pair in a set of beam pairs does not satisfy a threshold based on performing a relay link beam scanning process, and repeating the relay link beam scanning process to identify a first beam pair.

[0031] Some examples of the methods, apparatus, and non-transitory computer-readable media described herein may also include operations, features, components, or instructions for waiting for a random backoff period before repeating the relay link beam scanning process.

[0032] Some examples of the methods, apparatus, and non-transitory computer-readable media described herein may also include operations, features, components, or instructions for sending data to a second UE via a relay link to be forwarded to a base station.

[0033] Some examples of the methods, apparatus, and non-transitory computer-readable media described herein may also include operations, features, components, or instructions for receiving data from a base station via a second UE and a relay link.

[0034] A method of wireless communication by a base station is described. The method may include sending a relay link beam scanning configuration to a first UE and a second UE and receiving an indication of a relay link established between the first UE and the second UE based on the relay link beam scanning configuration.

[0035] 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 are executable by the processor to cause the apparatus to send a relay link beam scanning configuration to a first UE and a second UE, and receive an indication of a relay link established between the first UE and the second UE based on the relay link beam scanning configuration.

[0036] Another apparatus for wireless communication by a base station is described. The apparatus may include means for sending a relay link beam scanning configuration to a first UE and a second UE and receiving an indication of a relay link established between the first UE and the second UE based on the relay link beam scanning configuration.

[0037] A non-transitory computer-readable medium storing code for wireless communication by a base station is described. The code may include instructions executable by a processor to send a relay link beam scanning configuration to a first UE and a second UE, and receive an indication of a relay link established between the first UE and the second UE based on the relay link beam scanning configuration.

[0038] In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, sending a relay link beam scanning configuration may include operations, features, components, or instructions for sending a relay link beam scanning configuration, wherein the relay link beam scanning configuration indicates a beam scanning timing parameter for indicating at least one timing for performing a relay link beam scanning process.

[0039] In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, sending a relay link beam scanning configuration may include operations, features, components, or instructions for sending a relay link beam scanning configuration indicating periodic resources in which a relay link beam scanning process is performed.

[0040] In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, the periodic resource may be a configured synchronization signal block resource, or may be different from a configured synchronization signal block resource.

[0041] In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, sending a relay link beam scanning configuration may include operations, features, components, or instructions for sending a relay link beam scanning configuration, wherein the relay link beam scanning configuration instructs a first set of UEs including a first UE to perform a transmit beam scanning process in a first instance of a periodic resource, and a second set of UEs including a second UE to perform a receive beam scanning process in the first instance of a periodic resource.

[0042] In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, sending a relay link beam scanning configuration may include operations, features, components, or instructions for sending a relay link beam scanning configuration, wherein the relay link beam scanning configuration instructs a first set of UEs including a first UE to perform a receive beam scanning process in a first instance of a periodic resource, and a second set of UEs including a second UE to perform a transmit beam scanning process in the first instance of a periodic resource.

[0043] In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, sending a relay link beam scanning configuration may include operations, features, components, or instructions for sending a relay link beam scanning configuration, wherein the relay link beam scanning configuration indicates that a first plurality of UEs including a first UE are to perform one of a transmit beam scanning process or a receive beam scanning process in a first instance of a periodic resource, and a second plurality of UEs including a second UE are to perform the other of a transmit beam scanning process or a receive beam scanning process in the first instance of a periodic resource.

[0044] Some examples of the methods, apparatus, and non-transitory computer-readable media described herein may also include operations, features, components, or instructions for receiving a measurement report including one or more of beam pair measurements from a first UE, a second UE, or both, and sending instructions to the first UE, the second UE, or both to establish a relay link using the beam pair based on the measurement report.

[0045] Some examples of the methods, apparatus, and non-transitory computer-readable media described herein may also include operations, features, components, or instructions for receiving an identifier of a first UE, a second UE, or both, beam pair information of a first beam pair for establishing a relay link, or both.

[0046] Some examples of the methods, apparatus, and non-transitory computer-readable media described herein may also include operations, features, components, or instructions for receiving data of a first UE from a second UE, wherein the data of the first UE may be received by the second UE via a relay link and forwarded to a base station.

[0047] Some examples of the methods, apparatus, and non-transitory computer-readable media described herein may also include operations, features, components, or instructions for sending data to a second UE to be forwarded to the first UE via a relay link. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] Figure 1

[0013] Illustrated are examples of systems for wireless communications supporting establishment of UE-to-UE relay links in accordance with aspects of the present disclosure.

[0049] Figure 2 Another example of a wireless communication system supporting establishment of a UE-to-UE relay link according to aspects of the present disclosure is illustrated.

[0050] Figure 3 Illustrated is an example of a relay link process diagram that supports establishment of a UE-to-UE relay link in accordance with aspects of the present disclosure.

[0051] Figure 4 An example of a process flow diagram supporting establishment of a UE-to-UE relay link in accordance with aspects of the present disclosure is illustrated.

[0052] Figure 5 and 6 A block diagram of an apparatus supporting establishment of a UE-to-UE relay link according to aspects of the present disclosure is shown.

[0053] Figure 7 A block diagram of a communications manager supporting establishment of a UE-to-UE relay link in accordance with aspects of the present disclosure is shown.

[0054] Figure 8 A diagram of a system including devices supporting establishment of a UE-to-UE relay link in accordance with aspects of the present disclosure is shown.

[0055] Fig. 9 and 10 A block diagram of an apparatus supporting establishment of a UE-to-UE relay link according to aspects of the present disclosure is shown.

[0056] Fig.11 A block diagram of a communications manager supporting establishment of a UE-to-UE relay link in accordance with aspects of the present disclosure is shown.

[0057] Fig.12 A diagram of a system including devices supporting establishment of a UE-to-UE relay link in accordance with aspects of the present disclosure is shown.

[0058] Figures 13 to 21 A flow chart illustrating a method of supporting establishment of a UE-to-UE relay link according to aspects of the present disclosure is shown. DETAILED DESCRIPTION

[0059] A wireless communication system may include a UE that can communicate directly with other UEs. In some cases, a first UE may operate as a relay between a base station and a second UE. In a downlink scenario, a first UE may receive a signal from a base station and forward or retransmit the received signal to a second UE. In an uplink scenario, a first UE may receive a signal from a second UE and forward or retransmit the received signal to a base station. Relay links may be useful in some high-density scenarios, such as dense areas (e.g., highly concentrated buildings or structures) during special events, densely populated areas (e.g., stadiums, large shopping malls, offices, urban areas, etc.), or in other scenarios or places. In such a case, an obstruction (e.g., a physical object that interferes with a radio frequency signal) may interfere with the link established between the base station and the UE. A UE and another UE may establish a relay link in response to the obstruction to continue communication with the base station. In some cases, the relay between UEs in a communication system may be referred to as network-assisted UE collaboration (NAUC) or network control interaction service (NCIS) for high-density UE settings. Although the obstruction setting is an illustrative example of the need to establish a relay link, it is not expected that the relay link establishment is limited to this example.

[0060] In some wireless communication systems, various devices (e.g., UEs and base stations) can implement beamforming to improve signal transmission and reception quality. UEs in relay scenarios can also use beamforming technology to improve signal transmission and reception quality. The base station can control one or more aspects of beam coordination between UEs used to establish a relay link. In some cases, the base station sends a beam scanning configuration to one or more UEs to establish a relay link between UEs. The beam scanning configuration can indicate the timing of transmitting beam scanning to one or more UEs, the timing of receiving beam scanning to one or more UEs, and the periodic resources (and their identifiers) for performing the relay beam scanning process.

[0061] Based on the beam scanning configuration, the UE may perform a relay link beam scanning process to identify a beam pair for establishing a relay link (e.g., receiving and transmitting beams between two UEs). The relay beam scanning process may include sending and / or monitoring a reference signal based on the beam scanning configuration. In some cases, the UE may cycle through a beam pair set and generate a measurement report for each beam pair. Based on the measurement, the UE may select a beam pair for establishing a relay link. In some cases, performing a relay beam scanning process may include receiving a reference signal and decoding a synchronization signal sequence from the reference signal. Based on the synchronization signal sequence, the UE may determine a timing offset. In such a case, a relay link may be established based at least in part on the timing offset. When the beam pair is identified by one or more UEs, the one or more UEs may indicate the identified beam pair to the base station and perform a random access process to establish a relay link. Using the established relay link, one of the UEs may communicate with the base station via another UE.

[0062] Certain aspects of the subject matter described herein may be implemented to achieve one or more advantages. The described techniques may support improvements to communications in a relay link architecture, which reduces signaling overhead and improves reliability, among other advantages. Thus, the supported techniques may include improved network operation, and in some examples, may increase network efficiency, among other benefits.

[0063] Aspects of the present disclosure are initially described in the context of a wireless communication system. Aspects of the present disclosure are also described in the context of another wireless communication system, a relay link process diagram, and a process flow diagram. Aspects of the present disclosure are further illustrated by and described with reference to apparatus diagrams, system diagrams, and flow diagrams relating to establishment of a UE-to-UE relay link.

[0064] Figure 1 An example of a wireless communication system 100 that supports establishment of a UE-to-UE relay link according to various aspects of the present disclosure is illustrated. The wireless communication system 100 includes a base station 105, a UE 115, and a core network 130. In some examples, the wireless communication system 100 may be a long term evolution (LTE) network, an advanced LTE (LTE-A) network, an LTE-A Pro network, or a new radio (NR) network. In some cases, the wireless communication system 100 may support enhanced broadband communications, ultra-reliable (e.g., mission-critical) communications, low-latency communications, or communications with low-cost and low-complexity devices.

[0065] The base station 105 may communicate wirelessly with the UE 115 via one or more base station antennas. The base station 105 described herein may include or may be referred to by those skilled in the art as a base station transceiver, a radio base station, an access point, a radio transceiver, a NodeB, an eNodeB (eNB), a next generation NodeB or a giga NodeB (any of which may be referred to as a gNB), a home NodeB, a home eNodeB, or some other suitable term. The wireless communication system 100 may include different types of base stations 105 (e.g., macro cell base stations or small cell base stations). The UE 115 described herein may be able to communicate with various types of base stations 105 and network devices, including macro eNBs, small cell eNBs, gNBs, relay base stations, etc.

[0066] Each base station 105 may be associated with a particular geographic coverage area 110 in which it supports communications with various UEs 115. Each base station 105 may provide communications coverage for a respective geographic coverage area 110 via a communication link 125, and the communication link 125 between the base station 105 and the UE 115 may utilize one or more carriers. The communication link 125 shown in the wireless communication system 100 may include an uplink transmission from the UE 115 to the base station 105, or a downlink transmission from the base station 105 to the UE 115. Downlink transmissions may also be referred to as forward link transmissions, and uplink transmissions may also be referred to as reverse link transmissions.

[0067] The geographic coverage area 110 of the base station 105 can be divided into sectors that constitute a portion of the geographic coverage area 110, and each sector can be associated with a cell. For example, each base station 105 can provide communication coverage for a macro cell, a small cell, a hotspot, or other type of cell, or various combinations thereof. In some examples, the base station 105 can be mobile, thereby providing communication coverage for a mobile geographic coverage area 110. In some examples, different geographic coverage areas 110 associated with different technologies can overlap, and the overlapping geographic coverage areas 110 associated with different technologies can be supported by the same base station 105 or different base stations 105. The wireless communication system 100 can include, for example, a heterogeneous LTE / LTE-A / LTE-A Pro or NR network, in which different types of base stations 105 provide coverage for various geographic coverage areas 110.

[0068] The term "cell" refers to a logical communication entity used to communicate with base station 105 (e.g., via a carrier), and may be associated with an identifier (e.g., a physical cell identifier (PCID), a virtual cell identifier (VCID)) used to distinguish adjacent cells operating via the same or different carriers. In some examples, a carrier may support multiple cells, and different cells may be configured according to different protocol types that may provide access to different types of devices (e.g., machine type communication (MTC), narrowband Internet of Things (NB-IoT), enhanced mobile broadband (eMBB), or other). In some cases, the term "cell" may refer to a portion (e.g., a sector) of a geographic coverage area 110 on which the logical entity operates.

[0069] UE 115 may be dispersed throughout the wireless communication system 100, and each UE 115 may be fixed or mobile. UE 115 may also be referred to as a mobile device, a wireless device, a remote device, a handheld device, or a subscriber device, or some other suitable term, where "device" may also be referred to as a unit, a station, a terminal, or a client. UE 115 may also be a personal electronic device, such as a cellular phone, a personal digital assistant (PDA), a tablet computer, a laptop computer, or a personal computer. In some examples, UE 115 may also refer to a wireless local loop (WLL) station, an Internet of Things (IoT) device, an Internet of Everything (IoE) device, or an MTC device, etc., which may be implemented in various articles, such as appliances, vehicles, meters, etc.

[0070] Some UEs 115, such as MTC or IoT devices, may be low-cost or low-complexity devices and may provide automatic communication between machines (e.g., via machine-to-machine (M2M) communication). M2M communication or MTC may refer to data communication technology that allows devices to communicate with each other or with a base station 105 without human intervention. In some examples, M2M communication or MTC may include communication from devices that integrate sensors or meters to measure or capture information and relay the information to a central server or application, which may utilize the information or present the information to a person interacting with the program or application. Some UEs 115 may be designed to collect information or enable automatic behavior of machines. Examples of applications for MTC devices include smart metering, inventory monitoring, water level monitoring, equipment monitoring, healthcare monitoring, wildlife monitoring, weather and geological event monitoring, fleet management and tracking, remote security sensing, physical access control, and transaction-based commercial billing.

[0071] Some UEs 115 may be configured to employ operating modes that reduce power consumption, such as half-duplex communication (e.g., a mode that supports unidirectional communication via transmission or reception but not simultaneous transmission and reception). In some examples, half-duplex communication may be performed at a reduced peak rate. Other power saving techniques for UEs 115 include entering a power-saving "deep sleep" mode when not engaged in active communications, or operating over limited bandwidth (e.g., in accordance with narrowband communications). In some cases, UEs 115 may be designed to support critical functions (e.g., mission-critical functions), and the wireless communication system 100 may be configured to provide ultra-reliable communications for these functions.

[0072] In some cases, a UE 115 may also be able to communicate directly with other UEs 115 (e.g., using a peer-to-peer (P2P) or device-to-device (D2D) protocol). One or more UEs in a group of UEs 115 utilizing D2D communication may be within the geographic coverage area 110 of the base station 105. Other UEs 115 in this group may be outside the geographic coverage area 110 of the base station 105, or otherwise unable to receive transmissions from the base station 105. In some cases, a group of UEs 115 communicating via D2D communication may utilize a one-to-many (1:M) system in which each UE 115 transmits to each other UE 115 in the group. In some cases, the base station 105 facilitates the scheduling of resources for D2D communication. In other cases, D2D communication is performed between UEs 115 without involving the base station 105.

[0073] The base stations 105 may communicate with the core network 130 and may communicate with each other. For example, the base stations 105 may interface with the core network 130 via a backhaul link 132 (e.g., via S1, N2, N3, or other interface). The base stations 105 may communicate with each other directly (e.g., directly between the base stations 105) or indirectly (e.g., via the core network 130) via a backhaul link 134 (e.g., via X2, Xn, or other interface).

[0074] The core network 130 may provide user authentication, access authorization, tracking, Internet Protocol (IP) connectivity, and other access, routing, or mobility functions. The core network 130 may be an evolved packet core (EPC), which may include at least one mobility management entity (MME), at least one serving gateway (S-GW), and at least one packet data network (PDN) gateway (P-GW). The MME may manage non-access stratum (e.g., control plane) functions such as mobility, authentication, and bearer management of UEs 115 served by base stations 105 associated with the EPC. User IP packets may be delivered through the S-GW, which itself may be connected to the P-GW. The P-GW may provide IP address allocation and other functions. The P-GW may be connected to network operator IP services. Operator IP services may include access to the Internet, (multiple) intranets, IP multimedia subsystems (IMS), or packet switched (PS) streaming services.

[0075] At least some of the network devices, such as base stations 105, may include subcomponents, such as access network entities, which may be examples of access node controllers (ANCs). Each access network entity may communicate with UE 115 through multiple other access network transmission entities, which may be referred to as radio heads, smart radio heads, or transmit / receive points (TRPs). In some configurations, the various functions of each access network entity or base station 105 may be distributed across various network devices (e.g., radio heads and access network controllers) or combined into a single network device (e.g., base station 105).

[0076] The wireless communication system 100 can operate using one or more frequency bands typically in the range of 300 megahertz (MHz) to 300 gigahertz (GHz). Generally, the region from 300 MHz to 3 GHz is referred to as the ultra-high frequency (UHF) region or decimeter band because the wavelengths range from about 1 decimeter to 1 meter long. Buildings and environmental features may block or redirect UHF waves. However, the waves can fully penetrate the structure of the macrocell to provide services to the UE 115 located indoors. Compared with the transmission of smaller frequencies and longer waves using the high frequency (HF) or very high frequency (VHF) portion of the spectrum below 300 MHz, the transmission of UHF waves can be associated with smaller antennas and shorter distances (e.g., less than 100 km).

[0077] The wireless communication system 100 may also operate in the Super High Frequency (SHF) region using frequency bands from 3 GHz to 30 GHz, also known as centimeter bands. The SHF region contains frequency bands such as the 5 GHz Industrial, Scientific, and Medical (ISM) bands, which may be used opportunistically by devices that can tolerate interference from other users.

[0078] The wireless communication system 100 may also operate in the extremely high frequency (EHF) region of the spectrum (e.g., from 30 GHz to 300 GHz), also referred to as the millimeter band. In some examples, the wireless communication system 100 may support millimeter wave (mmW) communications between the UE 115 and the base station 105, and the EHF antennas of the various devices may be even smaller and more closely spaced than the UHF antennas. In some cases, this may facilitate the use of antenna arrays within the UE 115. However, the propagation of EHF transmissions may be subject to even greater atmospheric attenuation and a shorter range than SHF or UHF transmissions. The techniques disclosed herein may be employed between transmissions using one or more different frequency regions, and the designated use of frequency bands across these frequency regions may vary from country to country or regulatory agency.

[0079] In some cases, the wireless communication system 100 can utilize both licensed and unlicensed radio spectrum bands. For example, the wireless communication system 100 can adopt license assisted access (LAA), unlicensed LTE (LTE-U) radio access technology, or NR technology in an unlicensed band such as the 5GHz ISM band. When operating in an unlicensed radio spectrum band, wireless devices such as base stations 105 and UE 115 can adopt a pre-talk listen (LBT) process to ensure that the frequency channel is idle before sending data. In some cases, operations in unlicensed bands can be based on carrier aggregation configurations together with component carriers operating in licensed bands (e.g., LAA). Operations in unlicensed spectrum can include downlink transmissions, uplink transmissions, peer-to-peer transmissions, or a combination of these transmissions. Duplexing in unlicensed spectrum can be based on frequency division duplexing (FDD), time division duplexing (TDD), or a combination of both.

[0080] In some examples, the base station 105 or the UE 115 may be equipped with multiple antennas, which may be used to employ techniques such as transmit diversity, receive diversity, multiple-input multiple-output (MIMO) communication, or beamforming. For example, the wireless communication system 100 may use a transmission scheme between a transmitting device (e.g., a base station 105) and a receiving device (e.g., a UE 115), wherein the transmitting device is equipped with multiple antennas and the receiving device is equipped with one or more antennas. MIMO communication may employ multipath signal propagation to improve spectral efficiency by transmitting or receiving multiple signals via different spatial layers, which may be referred to as spatial multiplexing. For example, multiple signals may be transmitted by a transmitting device via different antennas or different antenna combinations. Similarly, multiple signals may be received by a receiving device via different antennas or different antenna combinations. Each of the multiple signals may be referred to as a separate spatial stream and may carry bits associated with the same data stream (e.g., the same codeword) or different data streams. Different spatial layers may be associated with different antenna ports for channel measurement and reporting. MIMO technology includes single-user MIMO (SU-MIMO), where multiple spatial layers are sent to the same receiving device, and multi-user MIMO (MU-MIMO), where multiple spatial layers are sent to multiple devices.

[0081] Beamforming (which may also be referred to as spatial filtering, directional transmission, or directional reception) is a signal processing technique that may be used at a transmitting device or a receiving device (e.g., a base station 105 or a UE 115) to shape or steer an antenna beam (e.g., a transmit beam or a receive beam) along a spatial path between the transmitting device and the receiving device. Beamforming may be achieved by combining signals communicated via antenna elements in an antenna array so that signals propagating in a particular orientation relative to the antenna array experience constructive interference, while other signals experience destructive interference. Adjustments to signals communicated via antenna elements may include the transmitting device or the receiving device applying a certain amplitude and phase offset to the signal carried via each antenna element associated with the device. The adjustments associated with each antenna element may be defined by a set of beamforming weights associated with a particular direction (e.g., relative to the antenna array of the transmitting device or the receiving device, or relative to some other direction).

[0082] In one example, the base station 105 may use multiple antennas or antenna arrays to perform beamforming operations for directional communication with the UE 115. For example, some signals (e.g., synchronization signals, reference signals, beam selection signals, or other control signals) may be sent multiple times by the base station 105 in different directions, which may include sending signals according to different beamforming weight sets associated with different transmission directions. The transmissions in different beam directions may be used to identify (e.g., by the base station 105 or a receiving device such as the UE 115) the beam direction for subsequent transmission and / or reception by the base station 105.

[0083] Some signals, such as data signals associated with a particular receiving device, may be transmitted by base station 105 in a single beam direction (e.g., a direction associated with a receiving device, such as UE 115). In some examples, a beam direction associated with transmission along a single beam direction may be determined based at least in part on signals transmitted in different beam directions. For example, UE 115 may receive one or more signals transmitted by base station 105 in different directions, and UE 115 may report to base station 105 an indication of the signal received with the highest signal quality or other acceptable signal quality. 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 for transmitting signals multiple times in different directions (e.g., for identifying a beam direction for subsequent transmission or reception by UE 115), or for transmitting signals in a single direction (e.g., for transmitting data to a receiving device).

[0084] When receiving various signals (such as synchronization signals, reference signals, beam selection signals, or other control signals) from the base station 105, a receiving device (e.g., UE 115, which may be an example of a mmW receiving device) may try multiple receive beams. For example, the receiving device may try multiple receive directions by receiving via different antenna subarrays, processing the received signals according to different antenna subarrays, receiving according to different receive beamforming weight sets applied to signals received at multiple antenna elements of an antenna array, or processing the received signals according to different receive beamforming weight sets applied to signals received at multiple antenna elements of an antenna array, any of which may be referred to as "listening" according to different receive beams or receive directions. In some examples, the receiving device may use a single receive beam to receive along a single beam direction (e.g., when receiving a data signal). A single receive beam may be aligned at a beam direction determined based at least in part on listening from different receive beam directions (e.g., a beam direction determined at least in part to have a highest signal strength, highest signal-to-noise ratio, or other acceptable signal quality based at least in part on listening from multiple beam directions).

[0085] In some cases, the antennas of a base station 105 or a UE 115 may be located within one or more antenna arrays that may support MIMO operations, or transmit or receive beamforming. For example, one or more base station antennas or antenna arrays may be co-located at an antenna assembly such as an antenna tower. In some cases, the antennas or antenna arrays associated with a base station 105 may be located at different geographic locations. A base station 105 may have an antenna array with multiple rows and columns of antenna ports that the base station 105 may use to support beamforming for communications with a UE 115. Likewise, a UE 115 may have one or more antenna arrays that may support various MIMO or beamforming operations.

[0086] In some cases, the wireless communication system 100 can be a packet-based network that operates according to a layered protocol stack. In the user plane, the communication at the bearer or packet data convergence protocol (PDCP) layer can be based on IP. The radio link control (RLC) layer can perform packet segmentation and reassembly to communicate through logical channels. The medium access control (MAC) layer can perform priority processing and multiplex logical channels into transport channels. The MAC layer can also use hybrid automatic repeat request (HARQ) to provide retransmission at the MAC layer to improve link efficiency. In the control plane, the radio resource control (RRC) protocol layer can provide the establishment, configuration and maintenance of the RRC connection between the UE 115 and the base station 105 or the core network 130 that supports the radio bearer for user plane data. At the physical layer, the transport channel can be mapped to the physical channel.

[0087] In some cases, UE 115 and base station 105 can support retransmission of data to increase the possibility of successfully receiving data. HARQ feedback is a technology that increases the possibility of correctly receiving data through communication link 125. HARQ can include a combination of error detection (e.g., using cyclic redundancy check (CRC)), forward error detection (FEC) and retransmission (e.g., automatic repeat request (ARQ)). HARQ can improve the throughput at the MAC layer under poor radio conditions (e.g., signal-to-noise ratio conditions). In some cases, a wireless device can support HARQ feedback for the same time slot, wherein the device can provide HARQ feedback for data received in the previous symbol in the time slot in a specific time slot. In other cases, the device can provide HARQ feedback in subsequent time slots or according to some other time intervals.

[0088] The time interval in LTE or NR can be expressed as a multiple of the basic time unit, which can be, for example, T s=1 / 30,720,000 second sampling period. The time intervals of the communication resources can be organized according to radio frames each having a duration of 10 milliseconds (ms), where the frame period can be represented as T f =307,200T s . Radio frames may be identified by a system frame number (SFN) ranging from 0 to 1023. Each frame may contain 10 subframes numbered from 0 to 9, and each subframe may have a duration of 1 ms. The subframe may be further divided into 2 time slots, each time slot having a duration of 0.5 ms, and each time slot may contain 6 or 7 modulation symbol periods (e.g., depending on the length of the cyclic prefix preceding each symbol period). In addition to the cyclic prefix, each symbol period may contain 2048 sampling periods. In some cases, a subframe may be the minimum scheduling unit of the wireless communication system 100 and may be referred to as a transmit time interval (TTI). In other cases, the minimum scheduling unit of the wireless communication system 100 may be shorter than a subframe, or may be dynamically selected (e.g., a burst of a shortened TTI (sTTI), or in a selected component carrier using sTTI).

[0089] In some wireless communication systems, a time slot may also be divided into a plurality of micro-slots containing one or more symbols. In some instances, a symbol of a micro-slot or a micro-slot may be a minimum scheduling unit. For example, the duration of each symbol may vary depending on the frequency band or subcarrier spacing of the operation. In addition, some wireless communication systems may implement time slot aggregation, wherein a plurality of time slots or micro-slots are aggregated together and used for communication between UE 115 and base station 105.

[0090] The term "carrier" refers to a set of radio spectrum resources that has a defined physical layer structure for supporting communications over the communication link 125. For example, a carrier of the communication link 125 may contain a portion of a radio spectrum band that operates according to a physical layer channel for a given radio access technology. Each physical layer channel may carry user data, control information, or other signaling. A carrier may be associated with a predefined frequency channel (e.g., an Evolved Universal Mobile Telecommunications System Terrestrial Radio Access (E-UTRA) Absolute Radio Frequency Channel Number (EARFCN)) and may be located according to a channel grid for discovery by a UE 115. A carrier may be downlink or uplink (e.g., in FDD mode), or configured to carry downlink communications and uplink communications (e.g., in TDD mode). In some examples, a signal waveform transmitted on a carrier may be composed of multiple subcarriers (e.g., using a multi-carrier modulation (MCM) technique such as orthogonal frequency division multiplexing (OFDM) or discrete Fourier transform spread OFDM (DFT-S-OFDM)).

[0091] The organization structure of the carrier may be different for different radio access technologies (e.g., LTE, LTE-A, LTE-A Pro, NR). For example, communications on a carrier may be organized based on TTIs or time slots, each of which may contain user data and control information or signaling to support decoding of the user data. A carrier may also contain dedicated acquisition signaling (e.g., synchronization signals or system information, etc.) and control signaling to coordinate the operation of the carrier. In some examples (e.g., in a carrier aggregation configuration), a carrier may also have acquisition signaling or control signaling to coordinate the operation of other carriers.

[0092] Physical channels may be multiplexed on a carrier according to various techniques. Physical control channels and physical data channels may be multiplexed on a downlink carrier, for example, using a time division multiplexing (TDM) technique, a frequency division multiplexing (FDM) technique, or a hybrid TDM-FDM technique. In some examples, control information sent in a physical control channel may be distributed in a cascaded manner between different control regions (e.g., between a common control region or common search space and one or more UE-specific control regions or UE-specific search spaces).

[0093] A carrier can be associated with a particular bandwidth of the radio spectrum, and in some examples, the carrier bandwidth can be referred to as the "system bandwidth" of the carrier or wireless communication system 100. For example, the carrier bandwidth can be one of a plurality of predetermined bandwidths of a carrier for a particular radio access technology (e.g., 1.4, 3, 5, 10, 15, 20, 40, or 80 MHz). In some examples, each served UE 115 can be configured to operate on part or all of the carrier bandwidth. In other examples, some UEs 115 can be configured to operate using a narrowband protocol type associated with a predefined portion or range (e.g., a set of RBs or subcarriers) within a carrier (e.g., an "in-band" deployment of a narrowband protocol type).

[0094] In a system using MCM technology, a resource element may consist of a symbol period (e.g., the duration of a modulation symbol) and a subcarrier, where the symbol period and the subcarrier spacing are inversely related. The number of bits carried by each resource element may depend on the modulation scheme (e.g., the order of the modulation scheme). Therefore, the more resource elements received by UE 115 and the higher the order of the modulation scheme, the higher the data rate of UE 115 can be. In a MIMO system, wireless communication resources may refer to a combination of radio spectrum resources, time resources, and space resources (e.g., space layers), and the use of multiple space layers may also increase the data rate of communication with UE 115.

[0095] A device (e.g., base station 105 or UE 115) of wireless communication system 100 may have a hardware configuration that supports communication on a specific carrier bandwidth, or may be configured to support communication on one of a set of carrier bandwidths. In some examples, wireless communication system 100 may include base station 105 and / or UE 115 that supports simultaneous communication via carriers associated with more than one different carrier bandwidths.

[0096] The wireless communication system 100 may support communication with the UE 115 on multiple cells or carriers, a feature that may be referred to as carrier aggregation or multi-carrier operation. The UE 115 may be configured with multiple downlink component carriers and one or more uplink component carriers according to a carrier aggregation configuration. Carrier aggregation may be used with both FDD component carriers and TDD component carriers.

[0097] In some cases, the wireless communication system 100 can utilize an enhanced component carrier (eCC). The eCC can be characterized by one or more characteristics, including a wider carrier or frequency channel bandwidth, a shorter symbol duration, a shorter TTI duration, or a modified control channel configuration. In some cases, the eCC can be associated with a carrier aggregation configuration or a dual connectivity configuration (e.g., when multiple serving cells have suboptimal or non-ideal backhaul links). The eCC can also be configured for use in an unlicensed spectrum or a shared spectrum (e.g., where more than one operator is allowed to use the spectrum). An eCC characterized as a wide carrier bandwidth can include one or more segments that can be utilized by a UE 115 that cannot monitor the entire carrier bandwidth or is otherwise configured to use a limited carrier bandwidth (e.g., to save power).

[0098] In some cases, an eCC may utilize a different symbol duration than other component carriers, which may include using a reduced symbol duration compared to the symbol duration of other component carriers. A shorter symbol duration may be associated with an increased spacing between adjacent subcarriers. A device utilizing an eCC, such as a UE 115 or a base station 105, may transmit a wideband signal (e.g., according to a frequency channel or carrier bandwidth of 20, 40, 60, 80 MHz, etc.) with a reduced symbol duration (e.g., 16.67 microseconds). A TTI in an eCC may consist of one or more symbol periods. In some cases, the TTI duration (i.e., the number of symbol periods in a TTI) may be variable.

[0099] The wireless communication system 100 may be an NR system that may utilize any combination of licensed, shared, and unlicensed spectrum bands, etc. The flexibility of eCC symbol duration and subcarrier spacing may allow the use of eCCs across multiple spectrums. In some examples, NR shared spectrum may specifically increase spectrum utilization and spectrum efficiency through dynamic vertical (e.g., across frequency domain) and horizontal (e.g., across time domain) sharing of resources.

[0100] In some cases, one or more UEs 115 may establish a relay link to communicate with the base station 105 based on a signal blocking condition. For example, the communication link 125 between the first UE 115 and the base station 105 may be blocked or interfered with by a blocking object (e.g., a physical object that interferes with a radio frequency (RF) communication signal). To remedy the affected link, the first UE 115 may autonomously or semi-autonomously establish a relay link with the second UE so that the second UE 115 can transmit signals between the first UE 115 and the base station 105.

[0101] Because UE 115 can be configured to use beamforming technology and communicate in high frequency (e.g., mmW), base station 105 can enable UE 115 to establish a beamformed relay link to maintain high throughput and signal quality of high frequency transmission. In order to enable the first UE 115 and the second UE 115 to establish a relay link, base station 105 can configure UE 115 using a relay link beam scanning configuration. The relay link beam scanning configuration can provide relay link discovery opportunities for multiple UEs 115 in the cells of each base station 105. In some cases, the relay link beam scanning configuration can indicate a beam scanning opportunity (e.g., a periodic resource) to a UE 115 or a set of UEs 115 in the cell to perform a relay link beam scanning process. In some cases, the indicated opportunity or the indicated periodic resource can be based on the capabilities of UE 115. The UE 115 in the cell can perform a relay link beam scanning process to identify relay link beam pairs between each UE 115. Using the identified beam pair, the UE 115 can establish a relay link (e.g., using a random access procedure) and use the established relay link to communicate with the base station 105. The relay link technology described herein can be implemented in various types of UEs 115, such as a repeater device or a repeater, a UE configured with a repeater function, a router, an intelligent node, etc.

[0102] Figure 2Another example of a wireless communication system 200 that supports establishment of a UE-to-UE relay link according to aspects of the present disclosure is illustrated. In some examples, the wireless communication system 200 can implement aspects of the wireless communication system 100. The wireless communication system 200 illustrates an example scenario in which a relay link can be established. The wireless communication system 200 includes various UEs 115, base stations 105, and clusters 205. The base station 105 can establish one or more beamformed links with the UE 115 using various transmit / receive beams 215. In some cases, the base station 105 can establish a beamformed link with the UE via the cluster 205 in the channel. The cluster 205 can be an example of a reflective object, such as a glass window, a lamp post, a metal object, or any other object that reflects or deflects energy. For example, the base station 105 uses beam 215-a, cluster 205-c, and beam 215-b to establish a beamformed link with the UE 115-d. The base station 105 may also establish a beamforming link with the UE 115 - e using the beam 215 - c , the cluster 205 - a , and the beam 215 - d .

[0103] In some cases, the blocking object 210 may block or interfere with the beamforming link. Figure 2 As shown, the obstruction 210 interferes with the beam 215-d, which may cause signal loss or signal quality degradation at the beamforming link between the base station 105 and the UE 115-e. The obstruction 210 may be an example of a physical obstruction such as a person (e.g., a person's hand or body), a vehicle, a building, leaves, etc., which interferes with the signal. In some cases, in order to re-establish a link between the base station 105 and the UE 115-e due to the obstruction 210, the device (e.g., the UE 115-e and the base station 105) may change the beam configuration so as to send in a different direction (e.g., using a different cluster 205) to establish a different or second link. However, in some cases, it may be difficult for the UE 115-e and the base station 105 to establish a new link based on various reasons, such as the cluster 205 is unavailable, the UE 115 in a mobile scenario, etc. In such a case, the UE 115-e may attempt to establish a link with another UE 115-d. When the base station 105 and the UE 115-e operate in a mmW scenario, the UE 115-e may attempt to establish a link with another UE 115 using a D2D protocol. However, in such a case, the UE 115 may sacrifice operating power and signal quality to establish such a link because the UE may discard or not utilize available capabilities (e.g., the device may utilize one of many available antennas). Therefore, the implementations described herein may be used to establish a relay link between UEs 115 while maintaining device capabilities (e.g., mmW and / or beamforming), which may result in enhanced signal throughput relative to other relay techniques.

[0104] The techniques described herein may provide for autonomous or semi-autonomous establishment of a relay link to a UE 115. In some cases, a UE may establish a relay link in response to an obstruction (e.g., obstruction 210) interfering with a channel established between a UE 115-e and a base station 105, or the link may be degraded due to Doppler. Thus, UE 115-e may establish a link with UE 115-d to facilitate beam failure recovery (or other purposes). For example, a relay link may also be utilized so that a UE 115 may collaborate in communications with a base station, so that a UE 115 may assist other UEs 115 in a network (e.g., CV2X without a gNB in ​​proximity), and so that a base station 105 may collaborate and transmit information to a UE 115 via multiple UEs 115.

[0105] To enable the UE 115 to establish a relay link, the gNB (e.g., base station 105) may intervene or coordinate the UEs 115 in the geographic coverage area 110. First, the gNB may determine which UEs 115 may be coordinated for the relay link. Next, the gNB may inform the two UEs 115 which RS / random access channel (RACH) resources to use for the relay link. The gNB may then relay beam / timing information (if available). Finally, the UE 115 may utilize the RS / RACH resources and beam / timing information (if available) to establish the relay link. However, this approach may require a central entity in the form of a gNB to establish the relay link. In some cases, the gNB may be too far away to perform coordination (e.g., when the UE is vehicle-mounted, the UE is in strong attenuation, etc.). The link between the UE and the gNB may be disconnected before the relay link between the UE and a different UE has been established (e.g., due to a sudden link failure caused by attenuation, blocking, etc., which may occur on the order of tens of milliseconds). Therefore, the implementations described herein enable the UE to autonomously or semi-autonomously establish a relay link. There may be exemplary tradeoffs associated with autonomous or semi-autonomous relay link establishment. In some cases, constant beam scanning incurs overhead (e.g., power consumption) at the expense of not requiring the gNB to perform "manual" coordination. Additionally, there may be a tradeoff between limited / minimal gNB intervention and maximum gNB intervention in relay link establishment.

[0106] To establish a relay link, the network / gNB (e.g., base station 105) may configure Tx beam sweeping opportunities for a first subset of UEs in a cell (e.g., coverage area 110) using parameters Trelay-beamsweep-tx-first-set-rx-second-set. For example, base station 105 may configure Tx beam sweeping opportunities for a first subset of UEs 115 including UEs 115-a and 115-e. The gNB may simultaneously configure Rx beam sweeping opportunities for other UEs 115 (a second set of UEs) in the cell. For example, base station 105 may configure Rx beam sweeping opportunities for a second set of UEs 115 including UEs 115-b, UE 115-c, and UE 115-d. The classification of UEs into the first subset and the second subset may be configured by the network / gNB or by randomization of the UEs themselves (e.g., based on their network IDs or time indexes corresponding to Tx / Rx). The RACH opportunities corresponding to the Tx-Rx opportunities may be allocated from the second set to the first set indicated by Trach-second-set-to-first-set. The gNB may also configure the Rx beam scanning opportunities for the first set and the Tx beam scanning opportunities for the second set using the parameter Trelay-beamsweep-tx-second-set-rx-first-set, and configure the RACH opportunities for the first set to the second set using Trach-first-set-to-second-set. In addition, the base station 105 may configure multiple set portions of the UE 115 in the cell. The configured beam scanning opportunities may allow multiple beam pairs to be scanned at both ends.

[0107] The UEs 115 in the first set may then perform Tx beam scanning, while the UEs 115 in the second set may perform Rx beam scanning with Trelay-beamsweep-tx-first-set-rx-second-set. Similarly, the UEs in the first set may perform Rx beam scanning with Trelay-beamsweep-tx-second-set-rx-first-set, while the second set may perform Tx beam scanning. In some cases, if all beam pairs are not scanned within one beam scanning opportunity, the process may be repeated at a subsequent opportunity. In some cases, the Tx set may use a specially designed PSS / SSS sequence or a traditional solution.

[0108] Assuming that a signal from a first UE 115 in the first set is received by a second UE 115 in the second set for at least one beam pair without collision from other transmissions (or with sufficient reference signal received power (RSRP)), the second UE can determine the timing offset based on PSS / SSS decoding. A pair of UEs 115 can use a variety of techniques to establish a relay link. In some cases, the pair of UEs 115 themselves establish a relay link. For example, a second UE 115 from the second set can use a RACH opportunity Trach-second-set-to-first-set to send a request for a relay link establishment process to the first UE in the first set. In another example, the second UE from the second set can record the record of the first UE 115 from the first set, and then use a future RACH opportunity (at N*Trach-second-set-to-first-set, where N>1 is assumed to start at t=0) to establish a relay link according to the needs of the second UE 115. In other cases, UE 115 may report discovery measurements to the network / gNB (e.g., base station 105), which may then determine whether and how to establish a relay link between UE 115. In such cases, the network allows autonomous discovery but may retain control over link establishment.

[0109] If the signal from the first UE in the first set is not received by any UE in the second set, this may be due to a collision of simultaneous transmissions, due to poor RSRP of the beam pair, etc. In case of a collision, the first UE in the first set may perform a random backoff on the beam scanning opportunity and perform beam scanning at the instance / opportunity of the backoff (expressed as M*Trelay-beamsweep-tx-first-set-rx-second-set, M>1). In case of poor RSRP, the first UE in the first set may perform beam scanning using a refined beam and attempt to establish the relay link again.

[0110] In some cases, the gNB may configure beam scanning opportunities for UEs 115 within a cell to implement relay link identification using different techniques. In one case, the configuration of the beam scanning opportunity corresponds to the base station 105 sending an identification of periodic resources for beam scanning. In some cases, the periodic resources may be the same as or different from the existing uplink and / or downlink synchronization signal block (SSB) resources at the UE 115. In some cases, the gNB may configure a first set of UEs 115 for sending beam scanning and a second set of UEs for receiving beam scanning on a first periodic resource together with appropriate RACH resources. In other cases, the gNB may configure the second set of UEs 115 for sending beam scanning and the first set of UEs 115 for receiving beam scanning on a second periodic resource together with appropriate RACH resources. In some examples, the gNB configures different sets of periodic resources for different sets of UEs within a cell. In other examples, the UE 115 may self-assign itself in one of the first set or the second set based on UE parameters such as a cell identifier, C-RNTI, S-TMSI, or a temporary identifier (TIN) used in the next update. Thus, based on the self-assignment, the UE 115 may perform Tx beam scanning or Rx beam scanning in one or more different periodic resources to identify the beam pair.

[0111] Based on the assignment or configuration, the UE 115 in the first set may perform transmit beam scanning, and the UE 115 in the second set may perform receive beam scanning on the first periodic resource. In addition, the UE 115 in the first set may perform receive beam scanning, and the UE in the second set may perform transmit beam scanning on the second periodic resource. In some cases, if each beam scanning opportunity allows scanning on a first number of beam pairs but not on a second number of beam pairs (e.g., based on the number of resources and the number of beam pairs), multiple resources may be used for beam scanning. The UEs in the first set may use a specially designed PSS / SSS sequence to perform transmit beam scanning on the first periodic resource, and the UEs 115 in the second set may use the same or different specially designed PSS / SSS sequence to perform transmit beam scanning on the second periodic resource. In some cases, if the received signal from the first UE 115 to the second UE 115 exceeds a threshold, the second UE 115 in the second set may use an immediate or future RACH resource opportunity associated with the first periodic beam scanning resource to communicate a request for a relay link establishment procedure (e.g., send a random access request) to the first UE 115 in the first set. Similarly, if the received signal from the second UE 115 to the first UE 115 exceeds a threshold, the first UE 115 in the first set may use an immediate or future RACH resource opportunity associated with the second periodic beam scanning resource to communicate a request for a relay link establishment procedure to the second UE 115 in the second set.

[0112] In some cases, the UE 115 may communicate the discovered measurements, such as the discovered UE ID, beam information, etc., to the gNB (e.g., base station 105) to assist in relay link establishment. In some examples, if no beam pair from any UE 115 in the second set triggers the relay link establishment process, the UE 115 in the first set may repeat the beam scanning with the refined beam. In some examples, the first UE 115 may perform random backoffs and attempt beam scanning at different instances of the first periodic resource for relay link establishment. Similarly, the second UE 115 may perform random backoffs and attempt beam scanning at different instances of the second periodic resource or relay link establishment.

[0113] like Figure 2 As shown, barrier 210 affects the link between UE 115-e and base station 105. In response, UE 115-e establishes a relay link with UE 115-d. The established relay link includes beam 215-e, cluster 205-b, and beam 215-f. Beams 215-e and 215-f can be identified using the techniques described herein.

[0114] Figure 3 An example of a relay link process diagram 300 that supports establishment of a UE-to-UE relay link in accordance with aspects of the present disclosure is illustrated. In some examples, devices of the relay link process diagram 300 may implement aspects of wireless communication systems 100 and 200. The relay link process diagram 300 includes a base station 105 and UEs 115-f and 115-g.

[0115] At 305, the base station 105 sends a relay link beam scanning configuration to the UE 115. In some cases, the base station 105 sends the relay link beam scanning configuration to all UEs in the cell or coverage area. In some examples, the base station 105 sends different corresponding beam configurations to different sets of UEs. For example, the beam scanning configuration may indicate that a first plurality of UEs including a first UE (e.g., UE 115-f) performs a transmit beam scanning process in a first instance of a periodic resource, and a second plurality of UEs including a second UE (e.g., UE 115-g) performs a receive beam scanning process in a first instance of a periodic resource. In such a case, the beam scanning configuration may also indicate that the first plurality of UEs will perform a receive beam scanning process in a second instance of the periodic resource, and the second plurality of UEs will perform a transmit beam scanning process in a second instance of the periodic resource. In some cases, the configuration indicates a scanning timing parameter, which indicates at least one timing (e.g., a transmit beam scanning timing and / or a receive beam scanning timing) for performing a relay link beam scanning process for each set of the respective sets of UEs 115.

[0116] At 310, UE 115 performs a relay link beam scanning process according to the relay link beam scanning configuration. Some operations of 310 may be performed during a first beam scanning opportunity or during a first instance of a periodic resource based on the relay link beam configuration. UE 115 may transmit a reference signal using a first subset of a plurality of beams in a first transmit opportunity and a second subset of a plurality of beams in a second transmit beam scanning opportunity based on the received beam scanning opportunity parameters. UE 115-g may monitor a reference signal transmitted by UE 115-f using a first subset of a plurality of beams in a first receive beam scanning opportunity and a second subset of a plurality of beams in a second receive beam scanning opportunity, the second receive beam scanning opportunity corresponding to the receive beam scanning opportunity parameters received at 305. The receive beam and / or transmit beam used to transmit the reference signal and / or monitor the reference signal may be based on a codebook indicated by base station 105 to UE 115 or a codebook preconfigured at UE 115.

[0117] At 315, UE 115 performs a relay link beam scanning process according to the relay link beam scanning configuration. Some operations of 315 may be performed during a second beam scanning opportunity or during a second instance of a periodic resource based on the relay link beam configuration (e.g., after the operation of 310). UE 115-g may transmit a reference signal using a first subset of the plurality of beams in a second transmit opportunity and a second subset of the plurality of beams in a second transmit beam scanning opportunity based on the received beam scanning opportunity parameters. UE 115-f may monitor the reference signal transmitted by UE 115-g using a first subset of the plurality of beams in a receive beam scanning opportunity and a second subset of the plurality of beams in a second receive beam scanning opportunity corresponding to the receive beam scanning opportunity parameters received at 305. The receive beam and / or transmit beam used to transmit the reference signal and / or monitor the reference signal may be based on a codebook indicated by base station 105 to UE 115 or a codebook preconfigured at UE 115.

[0118] At 320, a UE (e.g., UE 115-f) generates one or more measurements. The measurements may be generated during the beam scanning process of 305 and 310. A receiving UE (e.g., UE 115-g in 310 and UE 115-f in 315) may generate measurements for each beam pair based on a cycle through the beam pairs during the beam scanning process. In some cases, the measurements include received signal power. UE 115-f may send a measurement report to base station 105. The measurement report may include a UE identifier of UE 115-g, a received power measurement, an indication of a selected beam configuration, or some other information.

[0119] At 325, UE 115 selects a beam pair for establishing the relay link. For example, if the received signal power is above a threshold, the beam corresponding to the signal power above the threshold may be selected as the beam pair for establishing the relay link. Using the selected beam pair, the receiving UE may determine the timing offset based on the PSS / SSS decoding.

[0120] At 330, UE 115-f and UE 115-g establish a relay link. To establish the relay link, UE 115 may send a random access request to the other UE using an appropriate opportunity corresponding to the selected beam. The other UE may send a random access response to the first UE using the selected receive beam. In some cases, the random access opportunity may be recorded or saved and used at a subsequent time to send a random access request to establish the relay link. In some cases, base station 105 may determine whether and how to establish the relay link based on the received measurement report.

[0121] Figure 4An example of a process flow diagram 400 is illustrated to support establishment of a UE-to-UE relay link in accordance with aspects of the present disclosure. In some examples, an apparatus of process flow diagram 400 may implement aspects of wireless communication system 100. Process flow diagram 400 includes UE 115-a, UE 115-b, and base station 105.

[0122] At 405, the base station 105 sends a relay link beam scanning configuration to UE 115-a, and at 410, the base station 105 sends a relay link beam scanning configuration to UE 115-b. It should be understood that the operations at 405 and 410 can be performed simultaneously or concurrently. In some cases, the base station 105 broadcasts the relay link beam scanning configuration to the UEs 115 in the cell. In some cases, UE 115-a is the first UE of a first plurality of UEs that receive a first relay link beam scanning configuration, and UE 115-b is the second UE of a second plurality of UEs that receive a second relay link beam scanning configuration. The assignment of UE 115-a and UE 115-b to the respective groups can be based on various criteria, such as a network or cell identifier or the time of Tx / Rx. These configurations can indicate a transmit beam scanning timing parameter or indicate that a transmit or receive beam scanning process is performed at periodic intervals.

[0123] At 415, UE 115-a and UE 115-b perform a relay link beam scanning procedure using multiple beams based at least in part on the relay link beam scanning configuration. In some cases, UE 115-a may perform a receive beam scanning procedure at 415-a in which UE 115-a monitors a reference signal transmitted by UE 115-b during a beam scanning opportunity (or periodic resource) indicated by the configuration. At the same time, at 415-b, UE 115-b may transmit a reference signal using a subset of the transmit beams during the transmit beam scanning opportunity (or periodic resource).

[0124] At 420, UE 115-a may send a measurement report to base station 105. The measurement report may indicate received power measurements, UE identifier, beam configuration, and the like.

[0125] At 425, UE 115-a and UE 115-b perform a relay link beam scanning procedure using multiple beams based at least in part on the relay link beam scanning configuration. The operation at 425 can be considered to be the same as the beam scanning procedure discussed at 415. In some cases, UE 115-b can perform a receive beam scanning procedure at 425-b, in which UE 115-b monitors a reference signal transmitted by UE 115-a during a beam scanning opportunity (or periodic resource) indicated by the configuration. At the same time, at 425-a, UE 115-a can transmit a reference signal using a subset of the transmit beams during the transmit beam scanning opportunity (or periodic resource).

[0126] At 430, UE 115-b may send a measurement report to base station 105. The measurement report may indicate received power measurements, UE identifier, beam configuration, and the like.

[0127] At 435, UE 115-a selects a beam pair for establishing the relay link. The beam pair may be selected based on received signal power relative to a threshold (e.g., from a reference signal received at 415-a). In other cases, the selected beam pair may be indicated by a base station based on a received measurement report.

[0128] At 440, UE 115-a and UE 115-b may establish a relay link. A random access procedure may be used to establish the relay link. For example, UE 115-a may determine a timing offset for PSS / SSS decoding corresponding to the selected beam. UE 115-a may then send a random access request during a random access opportunity corresponding to the selected beam pair. UE 115-b may receive a random access response to establish the relay link.

[0129] At 445, UE 115-a transmits data to UE 115-b via the selected beam pair using the established relay link. At 450, UE 115-b transmits data to base station 105.

[0130] Figure 5 A block diagram 500 of a device 505 supporting establishment of a UE-to-UE relay link according to aspects of the present disclosure is shown. The device 505 may be an example of aspects of a UE 115 as described herein. The device 505 may include a receiver 510, a communication manager 515, and a transmitter 520. The device 505 may also include a processor. Each of these components may communicate with each other (e.g., via one or more buses).

[0131] The receiver 510 may receive information such as packets, user data, or control information associated with various information channels (e.g., control channels, data channels, and information related to the establishment of UE-to-UE relay links, etc.). The information may be delivered to other components of the device 505. The receiver 510 may be a reference Figure 8 Examples of aspects of the transceiver 820 are described. The receiver 510 may use a single antenna or a set of antennas.

[0132] The communication manager 515 may receive a relay link beam scanning configuration for establishing a relay link with a second UE from a base station; perform a relay link beam scanning process with the second UE using a beam set based on the relay link beam scanning configuration; select a first beam pair based on the relay link beam scanning process; and establish a relay link with the second UE using the first beam pair. The communication manager 515 may be an example of aspects of the communication manager 810 described herein.

[0133] An implementation may include: receiving a relay link beam scanning configuration for establishing a relay link with a second UE from a base station; performing a relay link beam scanning process with the second UE using a beam set based on the relay link beam scanning configuration; selecting a first beam pair based on the relay link beam scanning process; and establishing a relay link with the second UE using the first beam pair. This implementation may be used to provide advantages over alternative implementations, in which the UE may continuously waste resources for beam scanning until a potential link is identified. The implementation described herein may increase the efficiency of the device. For example, based on the indicated relay link beam scanning configuration, the UE may identify a beam pair for establishing a relay link during a scheduled beam scanning opportunity rather than during continuous scanning. In addition, because the UE may establish a relay link using a beamformed signal using the described implementation, the UE may maintain a high signal throughput provided by the beamformed signal in the relay link (e.g., in a high frequency communication environment such as mmW).

[0134] The communication manager 515 or its subcomponents may be implemented in hardware, in code executed by a processor (e.g., software or firmware), or any combination thereof. If implemented in code executed by a processor, the functions of the communication manager 515 or its subcomponents may be performed by 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 designed to perform the functions described in the present disclosure.

[0135] The communication manager 515 or its subcomponents may be physically located at various locations, including portions that are distributed so that functionality is implemented by one or more physical components at different physical locations. In some examples, according to various aspects of the present disclosure, the communication manager 515 or its subcomponents may be separate and distinct components. In some examples, according to various aspects of the present 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 the present disclosure, or a combination thereof.

[0136] Based on the beam selection relay link beam scanning configuration, the processor of UE 115 (e.g., as described in reference Figure 8 As described, the control receiver 510, the transmitter 520, or the transceiver 820) may identify resources for establishing a relay link (e.g., a beam pair for communicating with another UE). Therefore, based on the relay link beam scanning configuration, the UE 115 may turn on one or more processing units for performing a relay link beam scanning process, increase a processing clock, or a similar mechanism within the UE 115. In this way, when executing the process, the processor may be ready to effectively identify a beam pair for establishing a relay link.

[0137] Transmitter 520 can transmit signals generated by other components of device 505. In some examples, transmitter 520 can be co-located with receiver 510 in a transceiver component. For example, transmitter 520 can be a reference Figure 8 Examples of aspects of the described transceiver 820. The transmitter 520 may utilize a single antenna or a set of antennas.

[0138] In some examples, communication manager 515 may be implemented as an integrated circuit or chipset for a mobile device modem, and receiver 510 and transmitter 520 may be implemented as analog components (e.g., amplifiers, filters, antennas) coupled with the mobile device modem to enable wireless transmission and reception on one or more frequency bands.

[0139] The communication manager 515 as described herein may be implemented to achieve one or more potential advantages. One implementation may allow the device 505 to more efficiently coordinate relay link establishment, and more specifically allow the device 505 to autonomously or semi-autonomously establish a relay link with another device and use mmW / beamforming techniques. For example, the device 505 may receive a relay link beam scanning configuration from a base station and perform a beam scanning process to identify a beam configuration to be used in the relay link.

[0140] Based on implementing the relay link techniques described herein, the processor of UE 115 (e.g., as described in reference Figure 8As described, controlling the receiver 510, transmitter 520, or transceiver 820) may increase reliability in feedback communications and reduce signaling overhead, since the feedback configuration may not be explicitly indicated to the UE 115.

[0141] Figure 6 A block diagram 600 of a device 605 supporting establishment of a UE-to-UE relay link according to aspects of the present disclosure is shown. The device 605 may be an example of aspects of the device 505 or UE 115 as described herein. The device 605 may include a receiver 610, a communication manager 615, and a transmitter 640. The device 605 may also include a processor. Each of these components may communicate with each other (e.g., via one or more buses).

[0142] The receiver 610 may receive information such as packets, user data, or control information associated with various information channels (e.g., control channels, data channels, and information related to the establishment of UE-to-UE relay links, etc.). The information may be delivered to other components of the device 605. The receiver 610 may be a reference Figure 8 Examples of aspects of the transceiver 820 are described. The receiver 610 may use a single antenna or a set of antennas.

[0143] The communication manager 615 may be an example of aspects of the communication manager 515 as described herein. The communication manager 615 may include a configuration receiver 620, a beam scanning component 625, a beam selection component 630, and a relay link component 635. The communication manager 615 may be an example of aspects of the communication manager 810 as described herein.

[0144] The configuration receiver 620 may receive a relay link beam scanning configuration from a base station for establishing a relay link with a second UE.

[0145] The beam scanning component 625 can perform a relay link beam scanning procedure with the second UE using the beam set based on the relay link beam scanning configuration. The beam selecting component 630 can select a first beam pair based on the relay link beam scanning procedure.

[0146] The relay link component 635 can establish a relay link with the second UE using the first beam pair.

[0147] Transmitter 640 can transmit signals generated by other components of device 605. In some examples, transmitter 640 can be co-located with receiver 610 in a transceiver component. For example, transmitter 640 can be a reference Figure 8 Examples of aspects of the described transceiver 820. The transmitter 640 may utilize a single antenna or a set of antennas.

[0148] Figure 7 A block diagram 700 of a communication manager 705 supporting establishment of a UE-to-UE relay link in accordance with aspects of the present disclosure is shown. The communication manager 705 may be an example of aspects of the communication manager 515, the communication manager 615, or the communication manager 810 described herein. The communication manager 705 may include a configuration receiver 710, a beam scanning component 715, a beam selection component 720, a relay link component 725, a beam reporting component 730, a decoding component 735, a timing offset component 740, and a communication component 745. Each of these components may be in communication with each other (e.g., via one or more buses), directly or indirectly.

[0149] The configuration receiver 710 may receive a relay link beam scanning configuration from a base station to establish a relay link with a second UE. In some examples, the configuration receiver 710 may receive a relay link beam scanning configuration indicating a transmit beam scanning opportunity parameter for a first UE, wherein the relay link beam scanning process is performed within a first transmit beam scanning opportunity corresponding to the transmit beam scanning opportunity parameter.

[0150] An exemplary advantage of receiving a relay link beam scanning configuration indicating a transmit beam scanning opportunity parameter for a first UE is that the UE can utilize resources (e.g., battery and processing resources) during the transmit beam scanning opportunity to identify a beam pair for establishing a relay link, wherein the relay link beam scanning process is performed within a first transmit beam scanning opportunity corresponding to the transmit beam scanning opportunity parameter. In addition, the UE can maintain the increased signal throughput and quality provided by beamforming and high frequency transmission (e.g., mmW). In addition, a processing component of the device can be activated during the indicated transmit beam scanning opportunity, which can help to efficiently utilize processing resources.

[0151] In some examples, the configuration receiver 710 may receive a relay link beam scanning configuration indicating a receive beam scanning opportunity for a first UE, wherein a relay link beam scanning process is performed within a first receive beam scanning opportunity corresponding to a receive beam scanning opportunity parameter. In some examples, the configuration receiver 710 may receive a relay link beam scanning configuration indicating a periodic resource in which the relay link beam scanning process is performed. In some examples, the configuration receiver 710 may receive a relay link beam scanning configuration indicating that a first UE set including the first UE performs a transmit beam scanning process in a first instance of the periodic resource, and a second UE set including the second UE performs a receive beam scanning process in the first instance of the periodic resource.

[0152] An exemplary advantage of receiving a relay link beam scanning configuration indicating a receive beam scanning opportunity for a first UE is that the UE can utilize resources (e.g., battery and processing resources) during the receive beam scanning opportunity to identify a beam pair for establishing a relay link, wherein the relay link beam scanning process is performed within a first receive beam scanning opportunity corresponding to the receive beam scanning opportunity parameters. In addition, the UE can maintain the increased signal throughput and quality provided by beamforming and high frequency transmission (e.g., mmW). In addition, the processing components of the device can be activated during the receive beam scanning opportunity, which can help to efficiently utilize processing resources.

[0153] In some examples, the configuration receiver 710 may receive a relay link beam scanning configuration that instructs a first UE set including a first UE to perform a receive beam scanning process in a first instance of a periodic resource, and a second UE set including a second UE to perform a transmit beam scanning process in a first instance of a periodic resource. In some cases, the periodic resource is a configured synchronization signal block resource or is different from a configured synchronization signal block resource.

[0154] The beam scanning component 715 can use the beam set based on the relay link beam scanning configuration to perform a relay link beam scanning process with the second UE. In some examples, the beam scanning component 715 can use a first subset of the beam set in a first transmit beam scanning opportunity and a second subset of the beam set in a second transmit beam scanning opportunity corresponding to the transmit beam scanning opportunity parameters to transmit a reference signal. In some examples, the beam scanning component 715 can use a first subset of the beam set in a first receive beam scanning opportunity and a second subset of the beam set in a second receive beam scanning opportunity corresponding to the receive beam scanning opportunity parameters to monitor the reference signal sent by the second UE.

[0155] An exemplary advantage of transmitting a reference signal using a first subset of a beam set in a first transmit beam scanning opportunity and a second subset of a beam set in a second transmit beam scanning opportunity corresponding to the transmit beam scanning opportunity parameters is that the UE can utilize resources (e.g., battery and processing resources) during the transmit beam scanning opportunity to identify a beam pair for establishing a relay link. In addition, different transmit resources can be efficiently used on the first set and the second set, which can help to effectively utilize signal transmission resources. In addition, the UE can maintain the increased signal throughput and quality provided by beamforming and high frequency transmission (e.g., mmW). In addition, processing components of the device can be activated during each transmit beam scanning opportunity, which can help to efficiently utilize processing resources.

[0156] An exemplary advantage of monitoring a reference signal sent by a second UE using a first subset of multiple beams in a first receive beam scanning opportunity and a second subset of multiple beams in a second receive beam scanning opportunity corresponding to the receive beam scanning opportunity parameters is that the UE can efficiently utilize signal reception resources to identify a relay link beam pair during a corresponding receive beam scanning opportunity by identifying the reference signal. In addition, the UE can maintain the increased signal throughput and quality provided by beamforming and high frequency transmission (e.g., mmW). In addition, a processing component of the device can be activated during a corresponding receive beam scanning opportunity, which can help to efficiently utilize processing resources.

[0157] In some examples, the beam scanning component 715 can generate measurements of each beam pair in the beam pair set based on cycling through the beam pair set. In some examples, the beam scanning component 715 can send or monitor a reference signal generated based on a synchronization signal sequence. In some examples, the beam scanning component 715 can receive a reference signal. In some examples, the beam scanning component 715 can determine to perform a relay link beam scanning process based on at least one parameter.

[0158] In some examples, the beam scanning component 715 can detect that each beam pair in the set of beam pairs does not meet the threshold based on performing the relay link beam scanning process. In some examples, the beam scanning component 715 can repeat the relay link beam scanning process to identify the first beam pair. In some examples, the beam scanning component 715 can wait for a random backoff period before repeating the relay link beam scanning process.

[0159] In some cases, the at least one parameter is one or more of a network identifier, a cell identifier, a radio network temporary identifier, a temporary mobile subscriber identity, a temporary identifier, or any combination thereof.

[0160] The beam selecting component 720 can select the first beam pair based on the relay link beam scanning process. In some examples, the beam selecting component 720 can select the first beam pair based on the measurement.

[0161] The relay link component 725 can establish a relay link with the second UE using the first beam pair. In some examples, the relay link component 725 can send a random access channel message to the second UE using the transmit beam of the first beam pair at the first UE. In some examples, the relay link component 725 can receive a random access channel response from the second UE using the receive beam of the first beam pair at the first UE. In some examples, the relay link component 725 can send a random access request to the second UE in a random access opportunity.

[0162] In some examples, the relay link component 725 may receive a random access response from the second UE based on the random access request. In some examples, the relay link component 725 may receive a random access request from the second UE in a first random access opportunity or in a second random access opportunity that occurs after the first random access opportunity. In some examples, the relay link component 725 may send a random access response to the first UE based on the random access request.

[0163] The beam reporting component 730 can send a measurement report including one or more measurements to the base station, wherein the relay link is established based on receiving an instruction from the base station to establish the relay link using the first beam pair. In some examples, the beam reporting component 730 can send an identifier of the second UE, beam pair information of the first beam pair, or both to the base station.

[0164] The decoding component 735 can decode the synchronization signal sequence from the reference signal. The timing offset component 740 can determine the timing offset based on the synchronization signal sequence, wherein the relay link is established based on the timing offset. The communication component 745 can send data to the second UE via the relay link to forward to the base station. In some examples, the communication component 745 can receive data from the base station via the second UE and the relay link.

[0165] Figure 8 A diagram of a system 800 including a device 805 supporting establishment of a UE-to-UE relay link according to aspects of the present disclosure is shown. The device 805 may be an example of a device 505, a device 605, or a UE 115 as described herein or include components thereof. The device 805 may include components for two-way voice and data communications, including components for sending and receiving communications, the device 805 including a communication manager 810, an I / O controller 915, a transceiver 820, an antenna 825, a memory 830, and a processor 840. These components may be in electronic communication via one or more buses (e.g., bus 845).

[0166] The communication manager 810 can receive a relay link beam scanning configuration for establishing a relay link with a second UE from a base station; perform a relay link beam scanning process with the second UE using a beam set based on the relay link beam scanning configuration; select a first beam pair based on the relay link beam scanning process; and establish a relay link with the second UE using the first beam pair.

[0167] I / O controller 815 can manage input and output signals for device 805. I / O controller 815 can also manage peripheral devices that are not integrated into device 805. In some cases, I / O controller 815 can represent a physical connection or port to an external peripheral device. In some cases, I / O controller 815 can utilize an operating system, such as Or another known operating system. In other cases, I / O controller 815 can represent a modem, keyboard, mouse, touch screen or similar device, or can interact with these devices. In some cases, I / O controller 815 can be implemented as part of the processor. In some cases, a user can interact with device 805 via I / O controller 915 or via hardware components controlled by I / O controller 815.

[0168] The transceiver 820 may communicate bidirectionally via one or more antennas, wired or wireless links as described herein. For example, the transceiver 820 may represent a wireless transceiver and may communicate bidirectionally with another wireless transceiver. The transceiver 820 may also include a modem to modulate packets and provide the modulated packets to an antenna for transmission, and demodulate packets received from an antenna.

[0169] In some cases, a wireless device may contain a single antenna 825. However, in some cases, a device may have more than one antenna 825 capable of concurrently transmitting or receiving multiple wireless transmissions.

[0170] The memory 830 may include RAM and ROM. The memory 830 may store computer-readable, computer-executable code 835, including instructions that, when executed, cause the processor to perform the various functions described herein. In some cases, the memory 830 may include, among other things, a basic input / output system (BIOS), which may control basic hardware or software operations such as interaction with peripheral components or devices.

[0171] The processor 840 may include an intelligent hardware device (e.g., a general purpose processor, a DSP, a CPU, a microcontroller, an ASIC, an FPGA, a programmable logic device, a discrete gate or transistor logic component, a discrete hardware component, or any combination thereof). In some cases, the processor 840 may be configured to operate a memory array using a memory controller. In other cases, the memory controller may be integrated into the processor 840. The processor 840 may be configured to execute computer-readable instructions stored in a memory (e.g., memory 830) to cause the device 805 to perform various functions (e.g., functions or tasks that support establishing a UE-to-UE relay link).

[0172] The code 835 may include instructions for implementing various aspects of the present disclosure, including instructions for supporting wireless communications. The code 835 may be stored in a non-transitory computer-readable medium such as a system memory or other type of memory. In some cases, the code 835 may not be directly executed by the processor 840, but (e.g., when it is compiled and executed) may cause a computer to perform the functions described herein.

[0173] Fig. 9 A block diagram 900 of a device 905 supporting establishment of a UE-to-UE relay link according to aspects of the present disclosure is shown. The device 905 may be an example of aspects of a base station 105 as described herein. The device 905 may include a receiver 910, a communication manager 915, and a transmitter 920. The device 905 may also include a processor. Each of these components may communicate with each other (e.g., via one or more buses).

[0174] The receiver 910 may receive information such as packets, user data, or control information associated with various information channels (e.g., control channels, data channels, and information related to the establishment of UE-to-UE relay links, etc.). The information may be delivered to other components of the device 905. The receiver 910 may be a reference Fig.12 Examples of various aspects of the transceiver 1220 are described. The receiver 910 may use a single antenna or a set of antennas.

[0175] The communication manager 915 may send a relay link beam scanning configuration to the first UE and the second UE, and receive an indication of a relay link established between the first UE and the second UE based on the relay link beam scanning configuration. The communication manager 915 may be an example of aspects of the communication manager 1210 described herein.

[0176] The communication manager 915 or its subcomponents may be implemented in hardware, in code (e.g., software or firmware) executed by a processor, or any combination thereof. If implemented in code executed by a processor, the functions of the communication manager 915 or its subcomponents may be performed by a general purpose processor, a DSP, an application specific integrated circuit (ASIC), an FPGA or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described in the present disclosure.

[0177] The communication manager 915 or its subcomponents may be physically located at various locations, including portions that are distributed so that functionality is implemented by one or more physical components at different physical locations. In some examples, according to various aspects of the present disclosure, the communication manager 915 or its subcomponents may be separate and distinct components. In some examples, according to various aspects of the present disclosure, the communication manager 915 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 the present disclosure, or a combination thereof.

[0178] Transmitter 920 can transmit signals generated by other components of device 905. In some examples, transmitter 920 can be co-located with receiver 910 in a transceiver component. For example, transmitter 920 can be a reference Fig.12 Examples of various aspects of the described transceiver 1220. The transmitter 920 may utilize a single antenna or a set of antennas.

[0179] Fig.10 A block diagram 1000 of a device 1005 supporting establishment of a UE-to-UE relay link according to aspects of the present disclosure is shown. The device 1005 may be an example of aspects of the device 905 or base station 105 as described herein. The device 1005 may include a receiver 1010, a communication manager 1015, and a transmitter 1030. The device 1005 may also include a processor. Each of these components may communicate with each other (e.g., via one or more buses).

[0180] The receiver 1010 may receive information such as packets, user data, or control information associated with various information channels (e.g., control channels, data channels, and information related to the establishment of UE-to-UE relay links, etc.). The information may be delivered to other components of the device 1005. The receiver 1010 may be a reference Fig.12 Examples of various aspects of the transceiver 1220 are described. The receiver 1010 may use a single antenna or a set of antennas.

[0181] The communication manager 1015 may be an example of aspects of the communication manager 915 as described herein. The communication manager 1015 may include a beam scanning configuration component 1020 and a link indication receiver 1025. The communication manager 1015 may be an example of aspects of the communication manager 1210 as described herein.

[0182] The beam scanning configuration component 1020 may send the relay link beam scanning configuration to the first UE and the second UE. The link indication receiver 1025 may receive an indication of a relay link established between the first UE and the second UE based on the relay link beam scanning configuration.

[0183] Transmitter 1030 can transmit signals generated by other components of device 1005. In some examples, transmitter 1030 can be co-located with receiver 1010 in a transceiver component. For example, transmitter 1030 can be a reference Fig.12 Examples of various aspects of the described transceiver 1220. The transmitter 1030 may utilize a single antenna or a set of antennas.

[0184] Fig.11A block diagram 1100 of a communication manager 1105 supporting establishment of a UE-to-UE relay link in accordance with aspects of the present disclosure is shown. The communication manager 1105 may be an example of aspects of the communication manager 915, the communication manager 1015, or the communication manager 1210 described herein. The communication manager 1105 may include a beam scanning configuration component 1110, a link indication receiver 1115, a beam report receiver 1120, a relay link component 1125, and a communication component 1130. Each of these components may be in communication with each other (e.g., via one or more buses), directly or indirectly.

[0185] The beam scanning configuration component 1110 may send a relay link beam scanning configuration to the first UE and the second UE. In some examples, the beam scanning configuration component 1110 may send a relay link beam scanning configuration indicating a beam scanning timing parameter for indicating at least one timing for performing a relay link beam scanning process.

[0186] In some examples, beam scanning configuration component 1110 can send a relay link beam scanning configuration indicating a periodic resource in which to perform a relay link beam scanning procedure. In some examples, beam scanning configuration component 1110 can send a relay link beam scanning configuration indicating a first set of UEs including a first UE to perform a transmit beam scanning procedure in a first instance of the periodic resource, and a second set of UEs including a second UE to perform a receive beam scanning procedure in the first instance of the periodic resource.

[0187] In some examples, beam scanning configuration component 1110 can send a relay link beam scanning configuration that instructs a first set of UEs including a first UE to perform a receive beam scanning procedure in a first instance of a periodic resource, and a second set of UEs including a second UE to perform a transmit beam scanning procedure in a first instance of a periodic resource. In some cases, the periodic resource is a configured synchronization signal block resource or is different from a configured synchronization signal block resource.

[0188] The link indication receiver 1115 may receive an indication of a relay link established between the first UE and the second UE based on the relay link beam scanning configuration. The beam report receiver 1120 may receive a measurement report containing one or more beam pair measurements from the first UE, the second UE, or both.

[0189] In some examples, beam report receiver 1120 can receive an identifier of a first UE, a second UE, or both, beam pair information of a first beam pair for establishing a relay link, or both. Relay link component 1125 can send instructions to the first UE, the second UE, or both to establish a relay link using the beam pair based on the measurement report.

[0190] The communication component 1130 may receive data from the second UE that was received by the second UE and forwarded to the first UE via the relay link. In some examples, the communication component 1130 may send data to the second UE to be forwarded to the first UE via the relay link.

[0191] Fig.12 A diagram of a system 1200 including a device 1205 supporting establishment of a UE-to-UE relay link according to aspects of the present disclosure is shown. The device 1205 may be an example of a device 905, a device 1005, or a base station 105 as described herein or include components thereof. The device 1205 may include components for two-way voice and data communications, including components for sending 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 be in electronic communication via one or more buses (e.g., bus 1250).

[0192] The communication manager 1210 may send a relay link beam scanning configuration to the first UE and the second UE, and receive an indication of a relay link established between the first UE and the second UE based on the relay link beam scanning configuration.

[0193] The network communications manager 1215 may manage communications with the core network (eg, via one or more wired backhaul links). For example, the network communications manager 1215 may manage the sending of data communications for client devices such as one or more UEs 115 .

[0194] The transceiver 1220 may communicate bidirectionally via one or more antennas, wired or wireless links as described herein. For example, the transceiver 1220 may represent a wireless transceiver and may communicate bidirectionally with another wireless transceiver. The transceiver 1220 may also include a modem to modulate packets and provide the modulated packets to an antenna for transmission, and demodulate packets received from an antenna.

[0195] In some cases, a wireless device may include a single antenna 1225. However, in some cases, a device may have more than one antenna 1225 capable of concurrently transmitting or receiving multiple wireless transmissions.

[0196] Memory 1230 may include RAM, ROM, or a combination thereof. Memory 1230 may store computer readable code 1235 containing instructions that, when executed by a processor (e.g., processor 1240), cause the device to perform various functions described herein. In some cases, memory 1230 may include, among other things, BIOS, which may control basic hardware or software operations such as interaction with peripheral components or devices.

[0197] Processor 1240 may include an intelligent hardware device (e.g., a general purpose processor, a DSP, a CPU, a microcontroller, an ASIC, an FPGA, a programmable logic device, a discrete gate or transistor logic component, a discrete hardware component, or any combination thereof). In some cases, processor 1240 may be configured to operate a memory array using a memory controller. In some cases, the memory controller may be integrated into processor 1240. Processor 1240 may be configured to execute computer-readable instructions stored in a memory (e.g., memory 1230) to cause device 1205 to perform various functions (e.g., functions or tasks that support establishing a UE-to-UE relay link).

[0198] The inter-site communication manager 1245 can manage communications with other base stations 105 and can include a controller or scheduler for coordinating with other base stations 105 to control communications with UE 115. For example, the 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, the inter-site communication manager 1245 can provide an X2 interface within an LTE / LTE-A wireless communication network technology to provide communications between base stations 105.

[0199] The code 1235 may include instructions for implementing various aspects of the present disclosure, including instructions for supporting wireless communications. The code 1235 may be stored in a non-transitory computer-readable medium such as a system memory or other type of memory. In some cases, the code 1235 may not be directly executed by the processor 1240, but (e.g., when it is compiled and run) may cause the computer to perform the functions described herein.

[0200] Fig.13 A flow chart illustrating a method 1300 for supporting establishment of a UE-to-UE relay link according to aspects of the present disclosure is shown. The operations of the method 1300 may be implemented by the UE 115 or components thereof as described herein. For example, the operations of the method 1300 may be implemented by the UE 115 or components thereof as described in reference to Figures 5 to 8In some examples, the UE may execute an instruction set to control the functional elements of the UE to perform the functions described herein. Additionally or alternatively, the UE may use dedicated hardware to perform various aspects of the functions described herein.

[0201] At 1305, the UE may receive a relay link beam scanning configuration from a base station to establish a relay link with a second UE. The operations of 1305 may be performed according to the methods described herein. In some examples, aspects of the operations of 1305 may be described with reference to Figures 5 to 8 Describes how to configure the receiver to perform.

[0202] At 1310, the UE may perform a relay link beam scanning procedure with a second UE using a beam set based on the relay link beam scanning configuration. The operations of 1310 may be performed according to the methods described herein. In some examples, aspects of the operations of 1310 may be described with reference to Figures 5 to 8 The beam scanning component described is performed.

[0203] At 1315, the UE may select a first beam pair based on a relay link beam scanning process. The operations of 1315 may be performed according to the methods described herein. In some examples, aspects of the operations of 1315 may be described with reference to Figures 5 to 8 The beam selection component described is performed.

[0204] At 1320, the UE may establish a relay link with a second UE using the first beam pair. The operations of 1320 may be performed according to the methods described herein. In some examples, aspects of the operations of 1320 may be described with reference to Figures 5 to 8 The relay link components described are implemented.

[0205] Fig.14 A flow chart illustrating a method 1400 for supporting establishment of a UE-to-UE relay link according to aspects of the present disclosure is shown. The operations of the method 1400 may be implemented by the UE 115 or components thereof as described herein. For example, the operations of the method 1400 may be implemented by the UE 115 or components thereof as described in reference to Figures 5 to 8 In some examples, the UE may execute an instruction set to control the functional elements of the UE to perform the functions described herein. Additionally or alternatively, the UE may use dedicated hardware to perform various aspects of the functions described herein.

[0206] At 1405, the UE may receive a relay link beam scanning configuration from a base station to establish a relay link with a second UE. The operations of 1405 may be performed according to the methods described herein. In some examples, aspects of the operations of 1405 may be described with reference to Figures 5 to 8 Describes how to configure the receiver to perform.

[0207] At 1410, the UE may receive a relay link beam scanning configuration indicating a transmit beam scanning opportunity parameter for a first UE, wherein a relay link beam scanning process is performed within a first transmit beam scanning opportunity corresponding to the transmit beam scanning opportunity parameter. The operations of 1410 may be performed according to the methods described herein. In some examples, aspects of the operations of 1410 may be described with reference to Figures 5 to 8 Describes how to configure the receiver to perform.

[0208] At 1415, the UE may perform a relay link beam scanning procedure with a second UE using a beam set based on the relay link beam scanning configuration. The operations of 1415 may be performed according to the methods described herein. In some examples, aspects of the operations of 1415 may be described with reference to Figures 5 to 8 The beam scanning component described is performed.

[0209] At 1420, the UE may transmit a reference signal using a first subset of the beam set in the first transmit beam scanning opportunity and a second subset of the beam set in the second transmit beam scanning opportunity corresponding to the transmit beam scanning opportunity parameter. The operations of 1420 may be performed according to the methods described herein. In some examples, aspects of the operations of 1420 may be performed by reference Figures 5 to 8 The beam scanning component described is performed.

[0210] At 1425, the UE may select a first beam pair based on a relay link beam scanning process. The operations of 1425 may be performed according to the methods described herein. In some examples, aspects of the operations of 1425 may be described with reference to Figures 5 to 8 The beam selection component described is performed.

[0211] At 1430, the UE may establish a relay link with a second UE using the first beam pair. The operations of 1430 may be performed according to the methods described herein. In some examples, aspects of the operations of 1430 may be described with reference to Figures 5 to 8 The relay link components described are implemented.

[0212] Fig.15 A flow chart illustrating a method 1500 for supporting establishment of a UE-to-UE relay link according to aspects of the present disclosure is shown. The operations of the method 1500 may be implemented by the UE 115 or components thereof as described herein. For example, the operations of the method 1500 may be implemented by the UE 115 or components thereof as described herein. Figures 5 to 8 In some examples, the UE may execute an instruction set to control the functional elements of the UE to perform the functions described herein. Additionally or alternatively, the UE may use dedicated hardware to perform various aspects of the functions described herein.

[0213] At 1505, the UE may receive a relay link beam scanning configuration from a base station to establish a relay link with a second UE. The operations of 1505 may be performed according to the methods described herein. In some examples, aspects of the operations of 1505 may be described with reference to Figures 5 to 8 Describes how to configure the receiver to perform.

[0214] At 1510, the UE may receive a relay link beam scanning configuration indicating a receive beam scanning opportunity for a first UE, wherein a relay link beam scanning process is performed within a first receive beam scanning opportunity corresponding to the receive beam scanning opportunity parameter. The operations of 1510 may be performed according to the methods described herein. In some examples, aspects of the operations of 1510 may be described with reference to Figures 5 to 8 Describes how to configure the receiver to perform.

[0215] At 1515, the UE may perform a relay link beam scanning procedure with a second UE using a beam set based on the relay link beam scanning configuration. The operations of 1515 may be performed according to the methods described herein. In some examples, aspects of the operations of 1515 may be described with reference to Figures 5 to 8 The beam scanning component described is performed.

[0216] At 1520, the UE may select a first beam pair based on a relay link beam scanning process. The operations of 1520 may be performed according to the methods described herein. In some examples, aspects of the operations of 1520 may be described with reference to Figures 5 to 8 The beam selection component described is performed.

[0217] At 1525, the UE may establish a relay link with a second UE using the first beam pair. The operations of 1525 may be performed according to the methods described herein. In some examples, aspects of the operations of 1525 may be described with reference to Figures 5 to 8 The relay link components described are implemented.

[0218] At 1530, the UE may monitor a reference signal sent by a second UE using a first subset of beam sets in a first receive beam scanning opportunity and a second subset of beam sets in a second receive beam scanning opportunity corresponding to the receive beam scanning opportunity parameter. The operations of 1530 may be performed according to the methods described herein. In some examples, aspects of the operations of 1530 may be performed by a reference signal. Figures 5 to 8 The beam scanning component described is performed.

[0219] Fig.16A flow chart illustrating a method 1600 for supporting establishment of a UE-to-UE relay link according to aspects of the present disclosure is shown. The operations of the method 1600 may be implemented by the UE 115 or components thereof as described herein. For example, the operations of the method 1600 may be implemented by the UE 115 or components thereof as described herein. Figures 5 to 8 In some examples, the UE may execute an instruction set to control the functional elements of the UE to perform the functions described herein. Additionally or alternatively, the UE may use dedicated hardware to perform various aspects of the functions described herein.

[0220] At 1605, the UE may receive a relay link beam scanning configuration from a base station to establish a relay link with a second UE. The operations of 1605 may be performed according to the methods described herein. In some examples, aspects of the operations of 1605 may be described with reference to Figures 5 to 8 Describes how to configure the receiver to perform.

[0221] At 1610, the UE may perform a relay link beam scanning procedure with a second UE using a beam set based on the relay link beam scanning configuration. The operations of 1610 may be performed according to the methods described herein. In some examples, aspects of the operations of 1610 may be described with reference to Figures 5 to 8 The beam scanning component described is performed.

[0222] At 1615, the UE may select a first beam pair based on a relay link beam scanning process. The operations of 1615 may be performed according to the methods described herein. In some examples, aspects of the operations of 1615 may be described with reference to Figures 5 to 8 The beam selection component described is performed.

[0223] At 1620, the UE may establish a relay link with a second UE using the first beam pair. The operations of 1620 may be performed according to the methods described herein. In some examples, aspects of the operations of 1620 may be described with reference to Figures 5 to 8 The relay link components described are implemented.

[0224] At 1625, the UE may send a random access channel message to the second UE using the transmit beam of the first beam pair at the first UE. The operations of 1625 may be performed according to the methods described herein. In some examples, aspects of the operations of 1625 may be described with reference to Figures 5 to 8 The relay link components described are implemented.

[0225] At 1630, the UE may receive a random access channel response from the second UE using a receive beam of the first beam pair at the first UE. The operations of 1630 may be performed according to the methods described herein. In some examples, aspects of the operations of 1630 may be described with reference to Figures 5 to 8 The relay link components described are implemented.

[0226] Fig.17 A flow chart illustrating a method 1700 for supporting establishment of a UE-to-UE relay link according to aspects of the present disclosure is shown. The operations of the method 1700 may be implemented by the UE 115 or components thereof as described herein. For example, the operations of the method 1700 may be implemented by the UE 115 or components thereof as described in reference to Figures 5 to 8 In some examples, the UE may execute an instruction set to control the functional elements of the UE to perform the functions described herein. Additionally or alternatively, the UE may use dedicated hardware to perform various aspects of the functions described herein.

[0227] At 1705, the UE may receive a relay link beam scanning configuration from a base station to establish a relay link with a second UE. The operations of 1705 may be performed according to the methods described herein. In some examples, aspects of the operations of 1705 may be described with reference to Figures 5 to 8 Describes how to configure the receiver to perform.

[0228] At 1710, the UE may perform a relay link beam scanning procedure with a second UE using a beam set based on the relay link beam scanning configuration. The operations of 1710 may be performed according to the methods described herein. In some examples, aspects of the operations of 1710 may be described with reference to Figures 5 to 8 The beam scanning component described is performed.

[0229] At 1715, the UE may generate measurements for each beam pair in the beam pair set based on cycling through the beam pair set. The operations of 1715 may be performed according to the methods described herein. In some examples, aspects of the operations of 1715 may be described with reference to Figures 5 to 8 The beam scanning component described is performed.

[0230] At 1720, the UE may select a first beam pair based on a relay link beam scanning process. The operations of 1720 may be performed according to the methods described herein. In some examples, aspects of the operations of 1720 may be described with reference to Figures 5 to 8 The beam selection component described is performed.

[0231] At 1725, the UE may establish a relay link with a second UE using the first beam pair. The operations of 1725 may be performed according to the methods described herein. In some examples, aspects of the operations of 1725 may be described with reference to Figures 5 to 8 The relay link components described are implemented.

[0232] Fig.18A flow chart illustrating a method 1800 for supporting establishment of a UE-to-UE relay link according to aspects of the present disclosure is shown. The operations of the method 1800 may be implemented by the UE 115 or components thereof as described herein. For example, the operations of the method 1800 may be implemented by the UE 115 or components thereof as described herein. Figures 5 to 8 In some examples, the UE may execute an instruction set to control the functional elements of the UE to perform the functions described herein. Additionally or alternatively, the UE may use dedicated hardware to perform various aspects of the functions described herein.

[0233] At 1805, the UE may receive a relay link beam scanning configuration from a base station to establish a relay link with a second UE. The operations of 1805 may be performed according to the methods described herein. In some examples, aspects of the operations of 1805 may be described with reference to Figures 5 to 8 Describes how to configure the receiver to perform.

[0234] At 1810, the UE may receive a relay link beam scanning configuration indicating a periodic resource in which to perform a relay link beam scanning process. The operations of 1810 may be performed according to the methods described herein. In some examples, aspects of the operations of 1810 may be described with reference to Figures 5 to 8 Describes how to configure the receiver to perform.

[0235] At 1815, the UE may perform a relay link beam scanning procedure with a second UE using a beam set based on the relay link beam scanning configuration. The operations of 1815 may be performed according to the methods described herein. In some examples, aspects of the operations of 1815 may be described with reference to Figures 5 to 8 The beam scanning component described is performed.

[0236] At 1820, the UE may select a first beam pair based on a relay link beam scanning process. The operations of 1820 may be performed according to the methods described herein. In some examples, aspects of the operations of 1820 may be described with reference to Figures 5 to 8 The beam selection component described is performed.

[0237] At 1825, the UE may establish a relay link with a second UE using the first beam pair. The operations of 1825 may be performed according to the methods described herein. In some examples, aspects of the operations of 1825 may be described with reference to Figures 5 to 8 The relay link components described are implemented.

[0238] Fig.19A flow chart illustrating a method 1900 for supporting establishment of a UE-to-UE relay link according to aspects of the present disclosure is shown. The operations of the method 1900 may be implemented by the base station 105 or components thereof as described herein. For example, the operations of the method 1900 may be implemented by the base station 105 or components thereof as described in reference to Figures 9 to 12 In some examples, the base station may execute an instruction set to control the functional elements of the base station to perform the functions described herein. Additionally or alternatively, the base station may use dedicated hardware to perform various aspects of the functions described herein.

[0239] At 1905, the base station may send a relay link beam scanning configuration to the first UE and the second UE. The operations of 1905 may be performed according to the methods described herein. In some examples, aspects of the operations of 1905 may be described with reference to Figures 9 to 12 The beam scanning configuration components described are performed.

[0240] At 1910, a base station may receive an indication of a relay link established between a first UE and a second UE based on a relay link beam scanning configuration. The operations of 1910 may be performed according to the methods described herein. In some examples, aspects of the operations of 1910 may be described with reference to Figures 9 to 12 The described link instructs the receiver to perform.

[0241] Fig. 20 A flow chart illustrating a method 2000 for supporting establishment of a UE-to-UE relay link according to aspects of the present disclosure is shown. The operations of the method 2000 may be implemented by the base station 105 or components thereof as described herein. For example, the operations of the method 2000 may be implemented by the base station 105 or components thereof as described in reference to Figures 9 to 12 In some examples, the base station may execute an instruction set to control the functional elements of the base station to perform the functions described herein. Additionally or alternatively, the base station may use dedicated hardware to perform various aspects of the functions described herein.

[0242] At 2005, the base station may send a relay link beam scanning configuration to the first UE and the second UE. The operations of 2005 may be performed according to the methods described herein. In some examples, aspects of the operations of 2005 may be described with reference to Figures 9 to 12 The beam scanning configuration components described are performed.

[0243] At 2010, the base station may send a relay link beam scanning configuration indicating a beam scanning timing parameter for indicating at least one timing for performing a relay link beam scanning process. The operations of 2010 may be performed according to the methods described herein. In some examples, aspects of the operations of 2010 may be described by reference to Figures 9 to 12The beam scanning configuration components described are performed.

[0244] At 2015, the base station may receive an indication of a relay link established between the first UE and the second UE based on a relay link beam scanning configuration. The operations of 2015 may be performed according to the methods described herein. In some examples, aspects of the operations of 2015 may be performed by reference to Figures 9 to 12 The described link instructs the receiver to perform.

[0245] Fig.21 A flow chart illustrating a method 2100 for supporting establishment of a UE-to-UE relay link according to aspects of the present disclosure is shown. The operations of the method 2100 may be implemented by the base station 105 or components thereof as described herein. For example, the operations of the method 2100 may be implemented by the base station 105 or components thereof as described in reference to Figures 9 to 12 In some examples, the base station may execute an instruction set to control the functional elements of the base station to perform the functions described herein. Additionally or alternatively, the base station may use dedicated hardware to perform various aspects of the functions described herein.

[0246] At 2105, the base station may send a relay link beam scanning configuration to the first UE and the second UE. The operations of 2105 may be performed according to the methods described herein. In some examples, aspects of the operations of 2105 may be described with reference to Figures 9 to 12 The beam scanning configuration components described are performed.

[0247] At 2110, the base station may send a relay link beam scanning configuration indicating a periodic resource in which to perform a relay link beam scanning process. The operations of 2110 may be performed according to the methods described herein. In some examples, aspects of the operations of 2110 may be described with reference to Figures 9 to 12 The beam scanning configuration components described are performed.

[0248] At 2115, the base station may receive an indication of a relay link established between the first UE and the second UE based on the relay link beam scanning configuration. The operations of 2115 may be performed according to the methods described herein. In some examples, aspects of the operations of 2115 may be described with reference to Figures 9 to 12 The described link instructs the receiver to perform.

[0249] It should be noted that the methods described in this article describe possible implementations, and the operations and steps may be rearranged or otherwise modified, and other implementations are possible. In addition, aspects from two or more of these methods may be combined.

[0250] The technology described herein can be used in various wireless communication systems, such as code division multiple access (CDMA), time division multiple access (TDMA), frequency division multiple access (FDMA), orthogonal frequency division multiple access (OFDMA), single carrier frequency division multiple access (SC-FDMA) and other systems. CDMA systems can implement radio technologies such as CDMA2000, Universal Terrestrial Radio Access (UTRA), etc. CDMA2000 covers IS-2000, IS-95 and IS-856 standards. IS-2000 versions are generally referred to as CDMA2000 1X, 1X, etc. IS-856 (TIA-856) is generally referred to as CDMA2000 1xEV-DO, High Rate Packet Data (HRPD), etc. UTRA includes Wideband CDMA (WCDMA) and other variants of CDMA. TDMA systems can implement radio technologies such as Global System for Mobile Communications (GSM).

[0251] OFDMA systems can implement radio technologies such as Ultra Mobile Broadband (UMB), Evolved UTRA (E-UTRA), Institute of Electrical and Electronics Engineers (IEEE) 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802.20, Flash-OFDM, etc. UTRA and E-UTRA are part of Universal Mobile Telecommunications System (UMTS). LTE, LTE-A, and LTE-A Pro are versions of UMTS using E-UTRA. E-UTRA, UTRA, E-UTRA, UMTS, LTE, LTE-A, LTE-A Pro, NR, and GSM are described in documents from an organization named "3rd Generation Partnership Project" (3GPP). CDMA2000 and UMB are described in documents from an organization named "3rd Generation Partnership Project 2 (3GPP2)". The technology described herein can be used for the systems and radio technologies mentioned herein and other systems and radio technologies. Although aspects of LTE, LTE-A, LTE-A Pro, or NR systems may be described for example purposes, and LTE, LTE-A, LTE-A Pro, or NR terminology may be used in many of the descriptions, the techniques described herein are applicable beyond LTE, LTE-A, LTE-A Pro, or NR applications.

[0252] A macro cell generally covers a relatively large geographic area (e.g., a radius of several kilometers) and may allow unrestricted access to UEs subscribed to network provider services. Small cells may be associated with base stations with lower power than macro cells, and small cells may operate in the same or different frequency bands (e.g., licensed, unlicensed, etc.) as macro cells. According to various examples, small cells may include pico cells, femto cells, and micro cells. A pico cell, for example, may cover a small geographic area and may allow unrestricted access to UEs with service subscriptions to a network provider. A femto cell may also cover a small geographic area (e.g., a home) and may provide restricted access to UEs associated with the femto cell (e.g., UEs in a closed subscriber group (CSG), UEs for users in a home, etc.). An eNB for a macro cell may be referred to as a macro eNB. An eNB for a small cell may be referred to as a small cell eNB, a pico eNB, a femto eNB, or a home eNB. The eNB may support one or more (e.g., two, three, four, etc.) cells and may also support communications using one or more component carriers.

[0253] The wireless communication systems described herein may support synchronous or asynchronous operation. For synchronous operation, the base stations may have similar frame timing, and transmissions from different base stations may be approximately aligned in time. For asynchronous operation, the base stations may have different frame timing, and transmissions from different base stations may not be aligned in time. The techniques described herein may be used for synchronous or asynchronous operation.

[0254] The information and signals described herein may be represented using any of a variety of different technologies and techniques. For example, data, instructions, commands, information, signals, bits, symbols, and chips that may be mentioned throughout the description may be represented by voltage, current, electromagnetic waves, magnetic fields or magnetic particles, optical fields or optical particles, or any combination thereof.

[0255] The various illustrative blocks and components described in conjunction with the disclosure herein may be implemented or executed with a general purpose processor, DSP, ASIC, FPGA, or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. A general purpose processor may be a microprocessor, but in an alternative, the processor may be any conventional processor, controller, microcontroller, or state machine. The processor may also be implemented as a combination of computing devices (e.g., a combination of a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors combined with a DSP core, or any other such configuration).

[0256] The functions described herein may be implemented in hardware, software executed by a processor, firmware, or any combination thereof. If implemented in software executed by a processor, the functions may be stored on or sent via a computer-readable medium as one or more instructions or codes. 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 may be implemented using software, hardware, firmware, hard wiring, or any combination thereof run by a processor. Features that implement the functions may also be physically located in various locations, including being distributed so that portions of the functions are implemented at different physical locations.

[0257] Computer-readable media include both non-transitory computer storage media and communication media, and communication media include any media that helps to transfer a computer program from one place to another.Non-transitory storage media can be any available media that can be accessed by a general or special computer.As an example and not limitation, non-transitory computer-readable media can include random access memory (RAM), read-only memory (ROM), electrically erasable programmable ROM (EEPROM), flash memory, compact disk (CD) ROM or other optical disk storage, disk storage or other magnetic storage devices, or can be used to carry or store required program codes in the form of instructions or data structures and can be accessed by a general or special computer or a general or special processor. Any other non-transitory medium. In addition, any connection is appropriately referred to as a computer-readable medium. For example, if a coaxial cable, fiber optic cable, twisted pair, digital subscriber line (DSL) or wireless technologies such as infrared, radio and microwaves are used to send software from a website, server or other remote source, then coaxial cable, fiber optic cable, twisted pair, DSL or wireless technologies such as infrared, radio and microwaves are included in the definition of medium. Disk and disc as used herein include CD, laser disc, optical disc, digital versatile disc (DVD), floppy disk and Blu-ray disc, wherein disks usually reproduce data magnetically, while discs reproduce data optically using lasers. Combinations of the above are also included within the scope of computer-readable media.

[0258] As used herein, including in the claims, "or" as used in a list of items (e.g., a list of items beginning with a phrase such as "at least one" or "one or more") indicates an inclusive list, so that, for example, a list of at least one of A, B, or C refers to A or B or C or AB or AC or BC or ABC (i.e., A and B and C). In addition, as used herein, the phrase "based on" should not be interpreted as a reference to a closed set of conditions. For example, an exemplary step described as "based on condition A" can be based on both condition A and condition B without departing from the scope of the present disclosure. In other words, as used herein, the phrase "based on" should be interpreted in the same manner as the phrase "based at least in part on."

[0259] In the drawings, similar components or features may have the same reference number. In addition, various components of the same type may be distinguished by following the reference number with a dash and a second reference number that distinguishes between the similar components. If only the first reference number is used in the specification, the description applies to any one of the similar components having the same first reference number, regardless of the second reference number or other subsequent reference numbers.

[0260] The descriptions set forth herein in conjunction with the accompanying drawings describe example configurations and do not represent all examples that may be implemented or within the scope of the claims. The term "exemplary" as used herein means "used as an example, instance, or illustration," rather than "preferred" or "superior to other examples." In order to provide an understanding of the described techniques, the detailed description contains specific details. However, these techniques may be practiced without these specific details. In some instances, well-known structures and devices are shown in block diagram form to avoid obscuring the concepts of the described examples.

[0261] The description herein is provided to enable those skilled in the art to make or use the present disclosure. Various modifications to the present disclosure will be apparent to those skilled in the art, and the general principles defined herein may be applied to other variations without departing from the scope of the present disclosure. Therefore, the present disclosure is not limited to the examples and designs described herein, but should be given the broadest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for wireless communication by a first user equipment UE, comprising: receiving a relay link beam scanning configuration from an access network entity to establish a relay link with a second UE, wherein the relay link beam scanning configuration indicates a transmit beam scanning opportunity for the first UE, a receive beam scanning opportunity for the first UE, or both; performing a relay link beam scanning procedure with the second UE using a plurality of beams based at least in part on the relay link beam scanning configuration, wherein the relay link beam scanning procedure is performed during the transmit beam scanning opportunity, the receive beam scanning opportunity, or both; selecting a first beam pair based at least in part on the relay link beam scanning procedure; and A relay link is established with the second UE using the first beam pair.

2. The method according to claim 1, wherein: Receiving the relay link beam scanning configuration includes: Receive the relay link beam scanning configuration indicating the transmit beam scanning timing parameters for the first UE, wherein the relay link beam scanning process is performed within a first transmit beam scanning timing corresponding to the transmit beam scanning timing parameters.

3. The method according to claim 2, wherein: The process of performing the relay link beam scanning includes: A reference signal is transmitted using a first subset of the plurality of beams in the first transmit beam scanning opportunity and a second subset of the plurality of beams in a second transmit beam scanning opportunity corresponding to the transmit beam scanning opportunity parameter.

4. The method according to claim 1, wherein: Receiving the relay link beam scanning configuration includes: The relay link beam scanning configuration indicating receive beam scanning opportunity parameters for the first UE is received, wherein the relay link beam scanning process is performed within a first receive beam scanning opportunity corresponding to the receive beam scanning opportunity parameters.

5. The method according to claim 4, wherein: The process of performing the relay link beam scanning includes: A reference signal transmitted by the second UE is monitored using a first subset of the plurality of beams in the first receive beam scanning opportunity and a second subset of the plurality of beams in a second receive beam scanning opportunity corresponding to the receive beam scanning opportunity parameter.

6. The method according to claim 1, wherein: Establishing the relay link with the second UE includes: Sending, at the first UE, a random access channel message to the second UE using the transmit beam of the first beam pair; and A random access channel response is received at the first UE from the second UE using a receive beam of the first beam pair.

7. The method according to claim 1, wherein: The process of performing the relay link beam scanning includes: A measurement for each of the plurality of beam pairs is generated based at least in part on cycling through the plurality of beam pairs.

8. The method according to claim 7, further comprising: The first beam pair is selected based at least in part on the measurement.

9. The method according to claim 7, further comprising: and sending a measurement report including one or more of the measurements to the access network entity, wherein the relay link is established based at least in part on receiving an instruction from the access network entity to establish the relay link using the first beam pair.

10. The method according to claim 1, wherein: The process of performing the relay link beam scanning includes: A reference signal generated based at least in part on the synchronization signal sequence is sent or monitored.

11. The method according to claim 1, wherein: The process of performing the relay link beam scanning includes: receiving a reference signal; decoding a synchronization signal sequence from the reference signal; and A timing offset is determined based at least in part on the synchronization signal sequence, wherein the relay link is established based at least in part on the timing offset.

12. The method according to claim 1, wherein: Establishing the relay link with the second UE includes: Sending a random access request to the second UE at a random access opportunity; and A random access response is received from the second UE based at least in part on the random access request.

13. The method according to claim 1, wherein: Establishing the relay link with the second UE includes: receiving a random access request from the second UE in a first random access opportunity or in a second random access opportunity occurring after the first random access opportunity; and A random access response is sent to the first UE based at least in part on the random access request.

14. The method according to claim 1, further comprising: Send an identifier of the second UE, beam pair information of the first beam pair, or both to the access network entity.

15. The method according to claim 1, wherein: Receiving the relay link beam scanning configuration includes: The relay link beam scanning configuration is received indicating periodic resources in which the relay link beam scanning process is performed.

16. The method according to claim 15, wherein: The periodic resource is a configured synchronization signal block resource or a synchronization signal block resource different from the configured synchronization signal block resource.

17. The method according to claim 15, wherein: Receiving the relay link beam scanning configuration includes: Receive the relay link beam scanning configuration, and the relay link beam scanning configuration indicates that a first plurality of UEs including the first UE performs a transmit beam scanning process in a first instance of the periodic resource, and a second plurality of UEs including the second UE performs a receive beam scanning process in the first instance of the periodic resource.

18. The method according to claim 15, wherein: Receiving the relay link beam scanning configuration includes: Receive the relay link beam scanning configuration, and the relay link beam scanning configuration indicates that a first plurality of UEs including the first UE performs a receive beam scanning process in a first instance of the periodic resource, and a second plurality of UEs including the second UE performs a transmit beam scanning process in the first instance of the periodic resource.

19. The method of claim 1, further comprising: The relay link beam scanning procedure is performed based at least in part on a determination of at least one parameter.

20. The method according to claim 19, wherein: The at least one parameter is one or more of a network identifier, a cell identifier, a radio network temporary identifier, a temporary mobile subscriber identity, a temporary identifier, or any combination thereof.

21. The method according to claim 1, further comprising: detecting that each beam pair in a plurality of beam pairs fails to satisfy a threshold based at least in part on performing the relay link beam scanning process; as well as The relay link beam scanning process is repeated to identify the first beam pair.

22. The method according to claim 21, further comprising: A random backoff period is waited before repeating the relay link beam scanning process.

23. The method of claim 1, further comprising: Data is sent to the second UE via the relay link for forwarding to the access network entity.

24. The method of claim 1, further comprising: Data is received from the access network entity via the second UE and the relay link.

25. A method for wireless communication by an access network entity, comprising: Sending a relay link beam scanning configuration to a first user equipment UE and a second UE, wherein the relay link beam scanning configuration indicates a transmit beam scanning timing for the first UE, a receive beam scanning timing for the first UE, or both; and Receive an indication of a relay link established between the first UE and the second UE based at least in part on the relay link beam scanning configuration.

26. The method according to claim 25, wherein: Sending the relay link beam scanning configuration includes: The relay link beam scanning configuration indicating a beam scanning timing parameter is sent, and the beam scanning timing parameter is used to indicate at least one timing for performing a relay link beam scanning process.

27. The method according to claim 25, wherein: Sending the relay link beam scanning configuration includes: The relay link beam scanning configuration is sent indicating the periodic resources in which the relay link beam scanning process is performed.

28. The method according to claim 27, wherein: Sending the relay link beam scanning configuration includes: The relay link beam scanning configuration is sent, and the relay link beam scanning configuration indicates that a first plurality of UEs including the first UE will perform one of the transmitting beam scanning process or the receiving beam scanning process in a first instance of the periodic resource, and a second plurality of UEs including the second UE will perform the other of the transmitting beam scanning process or the receiving beam scanning process in the first instance of the periodic resource.

29. An apparatus for performing wireless communication by a first user equipment UE, comprising: means for receiving a relay link beam scanning configuration from an access network entity to establish a relay link with a second UE, wherein the relay link beam scanning configuration indicates a transmit beam scanning opportunity for the first UE, a receive beam scanning opportunity for the first UE, or both; means for performing a relay link beam scanning procedure with the second UE using a plurality of beams based at least in part on the relay link beam scanning configuration, wherein the relay link beam scanning procedure is performed during the transmit beam scanning opportunity, the receive beam scanning opportunity, or both; means for selecting a first beam pair based at least in part on the relay link beam scanning procedure; as well as Means for establishing a relay link with the second UE using the first beam pair.

30. An apparatus for wireless communication by an access network entity, comprising: means for sending a relay link beam scanning configuration to a first user equipment UE and a second UE, wherein the relay link beam scanning configuration indicates a transmit beam scanning opportunity for the first UE, a receive beam scanning opportunity for the first UE, or both; as well as Means for receiving an indication of a relay link established between the first UE and the second UE based at least in part on the relay link beam scanning configuration.

31. An apparatus for wireless communication by a first user equipment UE, comprising: processor; a memory in electronic communication with the processor; as well as Instructions are stored in the memory and can be executed by the processor to cause the device to perform the method according to any one of claims 1-24.

32. An apparatus for wireless communication by an access network entity, comprising: processor; a memory in electronic communication with the processor; as well as Instructions, stored in the memory and executable by the processor, to cause the device to perform a method according to any one of claims 25-28.

33. A non-transitory computer readable medium having code stored thereon, the code being executable by a processor to cause the processor to perform the method of any one of claims 1-24.

34. A non-transitory computer readable medium having code stored thereon, the code being executable by a processor to cause the processor to perform the method of any one of claims 25-28.

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