WO2022147712A1

WO2022147712A1 - Timing advance acquisition techniques for sidelink

Info

Publication number: WO2022147712A1
Application number: PCT/CN2021/070650
Authority: WO
Inventors: Yuwei REN; Shuanshuan Wu; Huilin Xu
Original assignee: Qualcomm Incorporated
Priority date: 2021-01-07
Filing date: 2021-01-07
Publication date: 2022-07-14

Abstract

Methods, systems, and devices for wireless communications are described. The method includes receiving a configuration that indicates resources for the first UE to use to perform, in an inactive state or an idle state of a wireless connection of the first UE and a base station, a measurement procedure on reference signals transmitted by one or more UEs, receiving, in the inactive state or the idle state, the reference signals on the resources indicated by the configuration, determining a timing advance value for uplink communications with the base station based on the first UE performing the measurement procedure on the received reference signals, and communicating, in the inactive or idle state for the wireless connection with the base station, on a sidelink connection with a second UE according to the determined timing advance value for the uplink communications with the base station.

Description

TIMING ADVANCE ACQUISITION TECHNIQUES FOR SIDELINK

FIELD OF TECHNOLOGY

The following relates to wireless communications, including timing advance acquisition techniques for sidelink.

BACKGROUND

Wireless communications systems are widely deployed to provide various types of communication content such as voice, video, packet data, messaging, broadcast, and so on. These systems may be capable of supporting communication with multiple users by sharing the 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, LTE-Advanced (LTE-A) systems, or LTE-A Pro systems, and fifth generation (5G) systems which may be referred to as New Radio (NR) systems. These systems may employ technologies such as code division multiple access (CDMA) , time division multiple access (TDMA) , frequency division multiple access (FDMA) , orthogonal frequency division multiple access (OFDMA) , or discrete Fourier transform spread orthogonal frequency division multiplexing (DFT-S-OFDM) . A wireless multiple-access communications system may include one or more base stations or one or more network access nodes, each simultaneously supporting communication for multiple communication devices, which may be otherwise known as user equipment (UE) .

In some cases, interference may occur when a first UE communicates over a sidelink connection using a misaligned timing advance while a second UE transmits signaling to another wireless device.

SUMMARY

The described techniques relate to improved methods, systems, devices, and apparatuses that support timing advance acquisition techniques for sidelink. Generally, the described techniques provide for a first user equipment (UE) receiving a configuration that indicates resources for the first UE to use to perform a measurement procedure on reference signals transmitted by one or more UEs, where the first UE performs the measurement procedure while the first UE is in an inactive state or an idle state of a wireless connection of the first UE and a base station. In some cases, the described techniques provide for a first UE receiving, in the inactive state or the idle state, the reference signals on the resources indicated by the configuration. In some cases, the first UE may determine a timing advance value for uplink communications with the base station based on the first UE performing the measurement procedure on the received reference signals. In some cases, the first UE may communicate, in the inactive or idle state for the wireless connection with the base station, on a sidelink connection with a second UE according to the determined timing advance value for the uplink communications with the base station.

A method for wireless communication at a first UE is described. The method may include receiving a configuration that indicates resources for the first UE to use to perform, in an inactive state or an idle state of a wireless connection of the first UE and a base station, a measurement procedure on reference signals transmitted by one or more UEs, receiving, in the inactive state or the idle state, the reference signals on the resources indicated by the configuration, determining a timing advance value for uplink communications with the base station based on the first UE performing the measurement procedure on the received reference signals, and communicating, in the inactive or idle state for the wireless connection with the base station, on a sidelink connection with a second UE according to the determined timing advance value for the uplink communications with the base station.

An apparatus for wireless communication at a first UE is described. The apparatus may include a processor, 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 configuration that indicates resources for the first UE to use to perform, in an inactive state or an idle state of a wireless connection of the first UE and a base station, a measurement procedure on reference signals transmitted by one or more UEs, receive, in the inactive state or the idle state, the reference signals on the resources indicated by the configuration, determine a timing advance value for uplink communications with the base station based on the first UE performing the measurement procedure on the received reference signals, and communicate, in the inactive or idle state for the wireless connection with the base station, on a sidelink connection with a second UE according to the determined timing advance value for the uplink communications with the base station.

Another apparatus for wireless communication at a first UE is described. The apparatus may include means for receiving a configuration that indicates resources for the first UE to use to perform, in an inactive state or an idle state of a wireless connection of the first UE and a base station, a measurement procedure on reference signals transmitted by one or more UEs, means for receiving, in the inactive state or the idle state, the reference signals on the resources indicated by the configuration, means for determining a timing advance value for uplink communications with the base station based on the first UE performing the measurement procedure on the received reference signals, and means for communicating, in the inactive or idle state for the wireless connection with the base station, on a sidelink connection with a second UE according to the determined timing advance value for the uplink communications with the base station.

A non-transitory computer-readable medium storing code for wireless communication at a first UE is described. The code may include instructions executable by a processor to receive a configuration that indicates resources for the first UE to use to perform, in an inactive state or an idle state of a wireless connection of the first UE and a base station, a measurement procedure on reference signals transmitted by one or more UEs, receive, in the inactive state or the idle state, the reference signals on the resources indicated by the configuration, determine a timing advance value for uplink communications with the base station based on the first UE performing the measurement procedure on the received reference signals, and communicate, in the inactive or idle state for the wireless connection with the base station, on a sidelink connection with a second UE according to the determined timing advance value for the uplink communications with the base station.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for performing the measurement procedure on the reference signals on the resources during an active state of the wireless connection of the first UE and the base station, where the received configuration further indicates for the first UE to continue to perform the measurement procedure on the reference signals on the resources indicated by the configuration for a time duration.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, receiving the configuration may include operations, features, means, or instructions for receiving a broadcast of system information that identifies the configuration.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, receiving the configuration may include operations, features, means, or instructions for receiving the configuration from the second UE over the sidelink connection or from a third UE over a different sidelink connection.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the configuration identifies resources configured for the second UE or the third UE to use to measure cross link interference at a respective one of the second UE or the third UE.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the configuration identifies resources configured for the second UE or the third UE to use to transmit uplink reference signals.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the uplink reference signals include sounding reference signals or demodulation reference signals.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for transmitting, to the base station, an indication of a capability of the first UE to perform a sidelink timing advance acquisition procedure to determine, in the inactive state or the idle state, a timing advance value for the sidelink connection that corresponds to the wireless connection with the base station, where the configuration may be received in accordance with the first UE transmitting the indication of the capability to the base station.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the configuration may be signaled to the first UE via radio resource control signaling or PC5 interface signaling.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for receiving, from the base station, a timing indicator that identifies a time of an expiration of the configuration.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, receiving the configuration may include operations, features, means, or instructions for determining that the configuration may be expired based on the timing indicator and requesting an updated configuration in response to determining that the configuration may be expired.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, receiving the configuration may include operations, features, means, or instructions for comparing the received configuration to a previous configuration the first UE received prior to entering the inactive state or the idle state and determining whether the received configuration differs from the previous configuration, where the determining of the timing advance value for uplink communications with the base station based on the first UE performing the measurement procedure on the received reference signals may be based on a determination that the received configuration differs from the previous configuration.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates an example of a wireless communications system that supports timing advance acquisition techniques for sidelink in accordance with aspects of the present disclosure.

FIG. 2 illustrates an example of a wireless communications system that supports timing advance acquisition techniques for sidelink in accordance with aspects of the present disclosure.

FIG. 3 illustrates an example of a process flow that supports timing advance acquisition techniques for sidelink in accordance with aspects of the present disclosure.

FIG. 4 illustrates an example of a timing structure that supports timing advance acquisition techniques for sidelink in accordance with aspects of the present disclosure.

FIG. 5 illustrates an example of a process flow that supports timing advance acquisition techniques for sidelink in accordance with aspects of the present disclosure.

FIG. 6 illustrates an example of a process flow that supports timing advance acquisition techniques for sidelink in accordance with aspects of the present disclosure.

FIG. 7 illustrates an example of a process flow that supports timing advance acquisition techniques for sidelink in accordance with aspects of the present disclosure.

FIGs. 8 and 9 show block diagrams of devices that support timing advance acquisition techniques for sidelink in accordance with aspects of the present disclosure.

FIG. 10 shows a block diagram of a communications manager that supports timing advance acquisition techniques for sidelink in accordance with aspects of the present disclosure.

FIG. 11 shows a diagram of a system including a device that supports timing advance acquisition techniques for sidelink in accordance with aspects of the present disclosure.

FIGs. 12 and 13 show flowcharts illustrating methods that support timing advance acquisition techniques for sidelink in accordance with aspects of the present disclosure.

DETAILED DESCRIPTION

The present techniques include timing advance acquisition techniques for sidelink. The present techniques provide improvements to operations associated with a user equipment (UE) acquiring timing advance for sidelink communications to minimize crosslink interference.

The Uu interface is the radio interface between a UE and a radio access network (e.g., base station) , while a sidelink (SL) interface may include the radio interface between adjacent UEs. In some SL interface designs, a UE with an active Uu connection may be configured to monitor for a Uu synchronized signal block (SSB) transmitted by a base station and use the reception timing of the SSB to determine a timing advance (TA) that the UE may use as its SL transmit timing. Because SL and Uu communications may be in separate frequency bandwidths, there may be little or no interference from SL transmission to the reception of an adjacent UE’s Uu uplink (UL) transmission to the base station. However, when Uu and SL communications use overlapping frequency bandwidths, using Uu downlink (DL) timing for SL transmission may cause interference to Uu UL reception at the base station.

When a UE is in an inactive Uu state, the UE may not expect to transmit Uu-related signals to or receive Uu-related signals from the base station. As a result, the UE may no longer be capable to track the Uu TA. Thus, interference (e.g., crosslink interference) may occur when the first UE communicates over the SL connection using a misaligned SL-based TA and the second UE transmits UL signaling to the base station.

The present techniques may at least partially or fully mitigate interference that results from the first UE communicating over the SL connection using a misaligned SL-based TA while the second UE transmits UL signaling to the base station. In some cases, the first UE in idle/inactive state may receive Uu inter-UE signaling, determine the timing of a Uu UL signal based on the received Uu inter-UE signaling, and use the determined timing for its sidelink transmission. In some cases, the first UE may determine that its sidelink transmission is in a frequency bandwidth also used by Uu communication and then determine the timing of the Uu UL signal in response to determining its sidelink transmission is in the frequency bandwidth also used by Uu communication.

In some examples, a first UE and a second UE may be adjacent and have an active SL connection. For these two UEs, the Uu communications may be inactive for the first UE (e.g., the first UE enters a Uu radio resource control (RRC) idle state or Uu RRC inactive state) , but the second UE may remain in or switch to an active state (e.g., second UE is Uu-connected) . The second UE may transmit UL signals to the base station over the Uu connection. In some cases, the first UE may transmit a capability indication to the base station that indicates the first UE is capable of acquiring the TA based on the Uu connection between the second UE and the base station. In response to the transmission of the capability indication, the first UE may receive a configuration (e.g., from the base station, or the second UE, or a third UE) . Based on the received configuration, the first UE may measure interference (e.g., crosslink interference) on the SL to estimate the TA for the Uu connection of the second UE and the base station. To avoid or minimize the interference, the first UE, still in the idle/inactive state, may use the estimated TA to communicate with the second UE over the SL connection.

Aspects of the subject matter described herein may be implemented to realize one or more advantages. The described techniques may support improvements in system efficiency such that a UE may minimize crosslink interference by determining a timing advance configuration of a Uu configuration that the UE receives from an external device (e.g., an adjacent UE, a base station, etc. ) . Additionally, described techniques may result in avoiding multiple retransmissions and failed transmissions, decreasing system latency, improving the reliability of a decoding procedure for uplink transmissions at a base station, and improving user experience.

FIG. 1 illustrates an example of a wireless communications system 100 that supports timing advance acquisition techniques for sidelink in accordance with aspects of the present disclosure. The wireless communications system 100 may include one or more base stations 105, one or more UEs 115, and a core network 130. In some examples, the wireless communications system 100 may be a Long Term Evolution (LTE) network, an LTE-Advanced (LTE-A) network, an LTE-A Pro network, or a New Radio (NR) network. In some examples, the wireless communications system 100 may support enhanced broadband communications, ultra-reliable (e.g., mission critical) communications, low latency communications, communications with low-cost and low-complexity devices, or any combination thereof.

The base stations 105 may be dispersed throughout a geographic area to form the wireless communications system 100 and may be devices in different forms or having different capabilities. The base stations 105 and the UEs 115 may wirelessly communicate via one or more communication links 125. Each base station 105 may provide a coverage area 110 over which the UEs 115 and the base station 105 may establish one or more communication links 125. The coverage area 110 may be an example of a geographic area over which a base station 105 and a UE 115 may support the communication of signals according to one or more radio access technologies.

The UEs 115 may be dispersed throughout a coverage area 110 of the wireless communications system 100, and each UE 115 may be stationary, or mobile, or both at different times. The UEs 115 may be devices in different forms or having different capabilities. Some example UEs 115 are illustrated in FIG. 1. The UEs 115 described herein may be able to communicate with various types of devices, such as other UEs 115, the base stations 105, or network equipment (e.g., core network nodes, relay devices, integrated access and backhaul (IAB) nodes, or other network equipment) , as shown in FIG. 1.

The base stations 105 may communicate with the core network 130, or with one another, or both. For example, the base stations 105 may interface with the core network 130 through one or more backhaul links 120 (e.g., via an S1, N2, N3, or other interface) . The base stations 105 may communicate with one another over the backhaul links 120 (e.g., via an X2, Xn, or other interface) either directly (e.g., directly between base stations 105) , or indirectly (e.g., via core network 130) , or both. In some examples, the backhaul links 120 may be or include one or more wireless links.

One or more of the base stations 105 described herein may include or may be referred to by a person having ordinary skill in the art as a base transceiver station, a radio base station, an access point, a radio transceiver, a NodeB, an eNodeB (eNB) , a next-generation NodeB or a giga-NodeB (either of which may be referred to as a gNB) , a Home NodeB, a Home eNodeB, or other suitable terminology.

A UE 115 may include or may be referred to as a mobile device, a wireless device, a remote device, a handheld device, or a subscriber device, or some other suitable terminology, where the “device” may also be referred to as a unit, a station, a terminal, or a client, among other examples. A UE 115 may also include or may be referred to as 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, a UE 115 may include or be referred to as a wireless local loop (WLL) station, an Internet of Things (IoT) device, an Internet of Everything (IoE) device, or a machine type communications (MTC) device, among other examples, which may be implemented in various objects such as appliances, or vehicles, meters, among other examples.

The UEs 115 described herein may be able to communicate with various types of devices, such as other UEs 115 that may sometimes act as relays as well as the base stations 105 and the network equipment including macro eNBs or gNBs, small cell eNBs or gNBs, or relay base stations, among other examples, as shown in FIG. 1.

The UEs 115 and the base stations 105 may wirelessly communicate with one another via one or more communication links 125 over one or more carriers. The term “carrier” may refer to a set of radio frequency spectrum resources having a defined physical layer structure for supporting the communication links 125. For example, a carrier used for a communication link 125 may include a portion of a radio frequency spectrum band (e.g., a bandwidth part (BWP) ) that is operated according to one or more physical layer channels for a given radio access technology (e.g., LTE, LTE-A, LTE-A Pro, NR) . Each physical layer channel may carry acquisition signaling (e.g., synchronization signals, system information) , control signaling that coordinates operation for the carrier, user data, or other signaling. The wireless communications system 100 may support communication with a UE 115 using carrier aggregation or multi-carrier operation. A 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 frequency division duplexing (FDD) and time division duplexing (TDD) component carriers.

Signal waveforms transmitted over a carrier may be made up of multiple subcarriers (e.g., using multi-carrier modulation (MCM) techniques such as orthogonal frequency division multiplexing (OFDM) or discrete Fourier transform spread OFDM (DFT-S-OFDM) ) . In a system employing MCM techniques, a resource element may consist of one symbol period (e.g., a duration of one modulation symbol) and one subcarrier, where the symbol period and 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, the coding rate of the modulation scheme, or both) . Thus, the more resource elements that a UE 115 receives and the higher the order of the modulation scheme, the higher the data rate may be for the UE 115. A wireless communications resource may refer to a combination of a radio frequency spectrum resource, a time resource, and a spatial resource (e.g., spatial layers or beams) , and the use of multiple spatial layers may further increase the data rate or data integrity for communications with a UE 115.

The time intervals for the base stations 105 or the UEs 115 may be expressed in multiples of a basic time unit which may, for example, refer to a sampling period of T _s= 1/ (Δf _max·N _f) seconds, where Δf _max may represent the maximum supported subcarrier spacing, and N _f may represent the maximum supported discrete Fourier transform (DFT) size. Time intervals of a communications resource may be organized according to radio frames each having a specified duration (e.g., 10 milliseconds (ms) ) . Each radio frame may be identified by a system frame number (SFN) (e.g., ranging from 0 to 1023) .

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

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

Physical channels may be multiplexed on a carrier according to various techniques. A physical control channel and a physical data channel may be multiplexed on a downlink carrier, for example, using one or more of time division multiplexing (TDM) techniques, frequency division multiplexing (FDM) techniques, or hybrid TDM-FDM techniques. A control region (e.g., a control resource set (CORESET) ) for a physical control channel may be defined by a number of symbol periods and may extend across the system bandwidth or a subset of the system bandwidth of the carrier. One or more control regions (e.g., CORESETs) may be configured for a set of the UEs 115. For example, one or more of the UEs 115 may monitor or search control regions for control information according to one or more search space sets, and each search space set may include one or multiple control channel candidates in one or more aggregation levels arranged in a cascaded manner. An aggregation level for a control channel candidate may refer to a number of control channel resources (e.g., control channel elements (CCEs) ) associated with encoded information for a control information format having a given payload size. Search space sets may include common search space sets configured for sending control information to multiple UEs 115 and UE-specific search space sets for sending control information to a specific UE 115.

In some examples, a base station 105 may be movable and therefore provide communication coverage for a moving geographic coverage area 110. In some examples, different geographic coverage areas 110 associated with different technologies may overlap, but the different geographic coverage areas 110 may be supported by the same base station 105. In other examples, the overlapping geographic coverage areas 110 associated with different technologies may be supported by different base stations 105. The wireless communications system 100 may include, for example, a heterogeneous network in which different types of the base stations 105 provide coverage for various geographic coverage areas 110 using the same or different radio access technologies.

The wireless communications system 100 may be configured to support ultra-reliable communications or low-latency communications, or various combinations thereof. For example, the wireless communications system 100 may be configured to support ultra-reliable low-latency communications (URLLC) or mission critical communications. The UEs 115 may be designed to support ultra-reliable, low-latency, or critical functions (e.g., mission critical functions) . Ultra-reliable communications may include private communication or group communication and may be supported by one or more mission critical services such as mission critical push-to-talk (MCPTT) , mission critical video (MCVideo) , or mission critical data (MCData) . Support for mission critical functions may include prioritization of services, and mission critical services may be used for public safety or general commercial applications. The terms ultra-reliable, low-latency, mission critical, and ultra-reliable low-latency may be used interchangeably herein.

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

In some systems, the D2D communication link 135 may be an example of a communication channel, such as a sidelink communication channel, between vehicles (e.g., UEs 115) . In some examples, vehicles may communicate using vehicle-to-everything (V2X) communications, vehicle-to-vehicle (V2V) communications, or some combination of these. A vehicle may signal information related to traffic conditions, signal scheduling, weather, safety, emergencies, or any other information relevant to a V2X system. In some examples, vehicles in a V2X system may communicate with roadside infrastructure, such as roadside units, or with the network via one or more network nodes (e.g., base stations 105) using vehicle-to-network (V2N) communications, or with both.

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) or 5G core (5GC) , which may include at least one control plane entity that manages access and mobility (e.g., a mobility management entity (MME) , an access and mobility management function (AMF) ) and at least one user plane entity that routes packets or interconnects to external networks (e.g., a serving gateway (S-GW) , a Packet Data Network (PDN) gateway (P-GW) , or a user plane function (UPF) ) . The control plane entity may manage non-access stratum (NAS) functions such as mobility, authentication, and bearer management for the UEs 115 served by the base stations 105 associated with the core network 130. User IP packets may be transferred through the user plane entity, which may provide IP address allocation as well as other functions. The user plane entity may be connected to IP services 150 for one or more network operators. The IP services 150 may include access to the Internet, Intranet (s) , an IP Multimedia Subsystem (IMS) , or a Packet-Switched Streaming Service.

Some of the network devices, such as a base station 105, may include subcomponents such as an access network entity 140, which may be an example of an access node controller (ANC) . Each access network entity 140 may communicate with the UEs 115 through one or more other access network transmission entities 145, which may be referred to as radio heads, smart radio heads, or transmission/reception points (TRPs) . Each access network transmission entity 145 may include one or more antenna panels. In some configurations, various functions of each access network entity 140 or base station 105 may be distributed across various network devices (e.g., radio heads and ANCs) or consolidated into a single network device (e.g., a base station 105) .

The wireless communications system 100 may 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 known as the ultra-high frequency (UHF) region or decimeter band because the wavelengths range from approximately one decimeter to one meter in length. The UHF waves may be blocked or redirected by buildings and environmental features, but the waves may penetrate structures sufficiently for a macro cell to provide service to the UEs 115 located indoors. The transmission of UHF waves may be associated with smaller antennas and shorter ranges (e.g., less than 100 kilometers) compared to transmission using the smaller frequencies and longer waves of the high frequency (HF) or very high frequency (VHF) portion of the spectrum below 300 MHz.

The wireless communications system 100 may utilize both licensed and unlicensed radio frequency spectrum bands. For example, the wireless communications system 100 may employ License Assisted Access (LAA) , LTE-Unlicensed (LTE-U) radio access technology, or NR technology in an unlicensed band such as the 5 GHz industrial, scientific, and medical (ISM) band. When operating in unlicensed radio frequency spectrum bands, devices such as the base stations 105 and the UEs 115 may employ carrier sensing for collision detection and avoidance. In some examples, operations in unlicensed bands may be based on a carrier aggregation configuration in conjunction with component carriers operating in a licensed band (e.g., LAA) . Operations in unlicensed spectrum may include downlink transmissions, uplink transmissions, P2P transmissions, or D2D transmissions, among other examples.

A base station 105 or a UE 115 may be equipped with multiple antennas, which may be used to employ techniques such as transmit diversity, receive diversity, multiple-input multiple-output (MIMO) communications, or beamforming. The antennas of a base station 105 or a UE 115 may be located within one or more antenna arrays or antenna panels, which 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 examples, antennas or antenna arrays associated with a base station 105 may be located in diverse geographic locations. A base station 105 may have an antenna array with a number of rows and columns of antenna ports that the base station 105 may use to support beamforming of communications with a UE 115. Likewise, a UE 115 may have one or more antenna arrays that may support various MIMO or beamforming operations. Additionally or alternatively, an antenna panel may support radio frequency beamforming for a signal transmitted via an antenna port.

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, a UE 115) to shape or steer an antenna beam (e.g., a transmit beam, a receive beam) along a spatial path between the transmitting device and the receiving device. Beamforming may be achieved by combining the signals communicated via antenna elements of an antenna array such that some signals propagating at particular orientations with respect to an antenna array experience constructive interference while others experience destructive interference. The adjustment of signals communicated via the antenna elements may include a transmitting device or a receiving device applying amplitude offsets, phase offsets, or both to signals carried via the antenna elements associated with the device. The adjustments associated with each of the antenna elements may be defined by a beamforming weight set associated with a particular orientation (e.g., with respect to the antenna array of the transmitting device or receiving device, or with respect to some other orientation) .

In some examples, a first UE (e.g., a UE 115) may receive a configuration that indicates resources for the first UE to use to perform a measurement procedure on reference signals transmitted by one or more other UEs. In some cases, the first UE may perform the measurement while the first UE is in an inactive state or an idle state of a wireless connection of the first UE and a base station (e.g., a base station 105) . In some cases, the first UE may receive, in the inactive state or the idle state, the reference signals on the resources indicated by the configuration. In some cases, the first UE may determine a timing advance value for uplink communications with the base station based on the first UE performing the measurement procedure on the received reference signals. In some cases, the first UE may communicate, while in the inactive or idle state for the wireless connection with the base station, on a sidelink connection with a second UE according to the determined timing advance value for the uplink communications with the base station. In some cases, the one or more other UEs may include the second UE.

FIG. 2 illustrates an example of a wireless communications system 200 that supports timing advance acquisition techniques for sidelink in accordance with aspects of the present disclosure. As illustrated, wireless communications system 200 may include UE 115-a, UE 115-b, and base station 105-a, any of which may be an example of a UE 115 or a base station 105, respectively, as described above with reference to FIG. 1.

Wireless communications system 200 may include a Uu connection 205 between base station 105-a and UE 115-a. In some examples, Uu connection 205 may include a downlink (e.g., forward link) and an uplink (e.g., reverse link) . In some examples, base station 105-a may use the downlink of Uu connection 205 to convey control and/or data information to UE 115-a. And UE 115-a may use the uplink of Uu connection 205 to convey control or data information to base station 105-a. In some cases, the downlink of Uu connection 205 may use different time and/or frequency resources than the uplink of Uu connection 205.

Wireless communications system 200 may include a sidelink 210 between UE 115-a and UE 115-b. In some cases, UE 115-b may transmit messages to and/or receive messages from UE 115-a over sidelink 210.

In some examples, wireless communications system 200 may include an idle/inactive Uu connection 220 between base station 105-a and UE 115-b. In the illustrated example, UE 115-a may be in a Uu connected state (e.g., based on Uu connection 205) , while UE 115-b may be in a Uu idle/inactive state (e.g., Uu RRC idle/inactive state based on idle/inactive Uu connection 220) .

In some examples, UE 115-a may transmit one or more uplink transmissions (e.g., uplink transmission 215) to base station 105-a over Uu connection 205. In some cases, UE 115-a may transmit uplink transmission 215 over Uu connection 205 at the same time or relatively the same time that UE 115-a transmits a message to UE 115-a over sidelink 210, which may result in interference 225 (e.g., crosslink interference) . Because UE 115-a is in the Uu connected state UE 115-a may continue to track the Uu TA (e.g., the TA for Uu connection 205) . However, because UE 115-b is in the idle/inactive Uu state, UE 115-b may not expect to transmit Uu-related signals to base station 105-a, or receive Uu-related signals from base station 105-a. Because UE 115-b is in the idle/inactive Uu state, UE 115-b may not be capable or configured to track the Uu TA. Thus, interference 225 may occur when UE 115-a transmits uplink transmission 215 to base station 105-a while UE 115-b uses a misaligned sidelink-based TA to transmit a sidelink message to UE 115-a over sidelink 210.

In some examples, UE 115-b may perform a measurement procedure (e.g., Uu inter-UE measurement procedure) to mitigate interference 225. In some cases, UE 115-b may perform the measurement procedure in response to UE 115-b determining that UE 115-a transmitting an uplink transmission to base station 105-a (e.g., uplink transmission 215) while UE 115-b transmits over sidelink 210 results in interference 225. In some cases, UE 115-b may perform the measurement procedure in response to UE 115-b determining that a resource (e.g., time/frequency resource) associated with UE 115-a transmitting an uplink transmission to base station 105-a overlaps with a resource (e.g., time/frequency resource) associated with UE 115-b transmitting over sidelink 210.

In some examples, UE 115-b may perform the measurement procedure on one or more transmissions (e.g., uplink transmission 215) from at least one UE (e.g., UE 115-a) . In some cases, the measurement procedure may include measuring crosslink interference. In one example of crosslink interference measurement, one or more UEs, for example including 115-a, may be configured to transmit reference signals (e.g., sounding reference signals (SRSs) , demodulation reference signals (DMRSs) , or other reference signals) in certain time/frequency resources for such transmissions. According to such configuration, one or more UEs, for example including 115-b, may be configured to listen for or monitor for such transmitted reference signals during at least a portion of the time/frequency resources, and perform measurement procedures on such transmitted reference signals, such as determining a received signal strength indicator (RSSI) , reference signal received power (RSRP) , signal to noise ratio (SNR) , signal to interference noise ratio (SINR) , or other measurement of interference based on the received reference signals to determine such crosslink interference. In some cases, UE 115-b may estimate a TA associated with the measured transmissions. In some cases, estimating the TA may be based on a proximity of UE 115-b to the one or more UEs whose transmissions UE 115-b is measuring. In some cases, estimating the TA may be based on an assumption in the computations of UE 115-b in estimating the TA, where the computations assume that the propagation delay is negligible (e.g., that the receive timing for the one or more measurements is relatively the same as the Uu transmit timing due to the proximity of the devices) . In some cases, UE 115-b may use the estimated TA on the sidelink transmissions to avoid interference 225.

In some examples, UE 115-b may use a reference signal resource (e.g., SRS, DMRS, etc. ) to perform the measurement procedure. In some cases, the reference signal resource may be configured by base station 105-a in Uu, by UE 115-a or by another UE in sidelink (e.g., PC5) . In some cases, UE 115-b may determine how to configure a reference signal resource for measurement in relation to sidelink 210. In some cases, UE 115-b may leverage the measurement procedure to estimate the Uu uplink transmit timing for UE 115-b in the Uu idle/inactive state.

The present techniques may support improvements in system efficiency such that UE 115-b may minimize crosslink interference by determining a timing advance configuration of a Uu configuration that UE 115-b receives from an external device (e.g., from base station 105-a, from another base station, from UE 115-a, or from another sidelink UE) . Additionally, described techniques may result in UE 115-a or UE 115-b or base station 105-a, or any combination thereof, avoiding multiple retransmissions and failed transmissions, decreasing system latency, improving the reliability of a decoding procedure for received uplink transmissions at base station 105-a, and improving user experience.

FIG. 3 illustrates an example of a process flow 300 that supports timing advance acquisition techniques for sidelink in accordance with aspects of the present disclosure. As illustrated, process flow 300 may include UE 115-c, UE 115-d, and base station 105-b, any of which may be an example of a UE 115 or a base station 105, respectively, as described above with reference to FIG. 1 or FIG. 2. In some cases, UE 115-d may be in an inactive state or an idle state of a Uu connection between UE 115-d and base station 105-b. In some cases, UE 115-c may be in an Uu connected state with base station 105-b. In some cases, a sidelink connection may exist between UE 115-d and UE 115-c.

At 305, base station 105-b may send to UE 115-d a configuration (e.g., a Uu inter-UE measurement configuration, a Uu network configuration, a crosslink interference measurement configuration, etc. ) . In some cases, the configuration may indicate resources that UE 115-d may use to perform, in the idle/inactive state, a measurement procedure on reference signals transmitted by one or more UEs (e.g., UE 115-c) .

At 310, UE 115-c may transmit one or more uplink transmissions. In some cases, UE 115-c may transmit one or more Uu uplink transmissions to base station 105-b.

At 315, UE 115-d may perform a measurement procedure based on the configuration received at 305. In some cases, UE 115-d may receive at least one of the one or more uplink transmissions (e.g., Uu inter-UE signal) transmitted by UE 115-c at 310. In some cases, UE 115-d may perform the measurement procedure on reference signals associated with the one or more transmissions at 310.

At 320, based on a result of the measurement procedure UE 115-d may estimate transmit timing information (e.g., Uu uplink transmit timing advance) associated with the one or more uplink transmissions transmitted by UE 115-c at 310.

At 325, UE 115-d may use the estimated transmit timing information to transmit a message to UE 115-c over a sidelink connection between UE 115-d and UE 115-c. In some cases, UE 115-d may use estimated Uu timing information as the timing information for a sidelink transmission from UE 115-d to UE 115-c.

Accordingly, UE 115-d using the estimated transmit timing information results in UE 115-d mitigating interference that would otherwise occur when UE 115-d communicates with UE 115-c over a sidelink connection using a misaligned timing advance while UE 115-c transmits signaling to another wireless device (e.g., to base station 105-b, etc. ) . Additionally, UE 115-d using the estimated transmit timing information results in UE 115-d or UE 115-c or base station 105-b, or any combination thereof, avoiding multiple retransmissions and failed transmissions, decreasing system latency, improving the reliability of a decoding procedure for received uplink transmissions at base station 105-b, and improving user experience.

FIG. 4 illustrates an example of a timing structure 400 that supports timing advance acquisition techniques for sidelink in accordance with aspects of the present disclosure. As illustrated, timing structure 400 may depict operations and techniques associated with a UE 115 or base station 105, as described above with reference to FIGs. 1, 2, and 3. In some cases, timing structure 400 illustrates how to configure reference signal resources for Uu inter-UE measurement for a UE in a Uu idle/inactive state (e.g., a UE 115 as described above with reference to FIGs. 1, 2, and 3) to facilitate timing advance acquisition for sidelink.

In the illustrated example, Uu connected time span 415 may indicate a time period when a UE is in the Uu connected state. Accordingly, during time slot 405-a the UE may be in an active Uu connected state. During time slot 405-a the UE in the active Uu connected state may measure reference signal 410-a (e.g., a Uu inter-UE signal) . Similarly, during time slot 405-c the UE in the active Uu connected state may measure reference signal 410-b.

In the illustrated example, Uu idle/inactive time span 420 may indicate a time period when the UE is in the Uu idle/inactive state. Accordingly, during time slot 405-e the UE in the idle/inactive Uu state may measure reference signal 410-c. Similarly, during time slot 405-n the UE in the idle/inactive Uu state may measure reference signal 410-n.

In some cases, the UE in the idle/inactive state may determine whether a resource signal resource the UE received while in the Uu connected state (e.g., during Uu connected time span 415) has varied. In some cases, when the UE in the idle/inactive state accesses a network (e.g., access a base station via preconfigured uplink resource (PUR) or downlink control information (DCI) ) , the UE may determine whether the configuration the UE received while in the Uu connected state (e.g., Uu connected time span 415) has varied. In some cases, the UE determines an indicator that indicates to show whether SRS resource has changed.

In some examples, time period 425 may be associated with a timer of a base station (e.g., a base station 105 as described above with reference to FIGs. 1, 2, and 3) . In some cases, the timer may be associated with a configuration that the UE receives from another device (e.g., a base station or sidelink UE) . In some cases, the timer may indicate an expiration of the received configuration. In some cases, the UE may receive, from the base station, a timing indicator that indicates an aspect of time period 425 (e.g., a start time, an end time, a time length, an expiration, etc. ) . In some cases, the timing indicator may indicate an expiration time of the configuration. In some cases, the time period 425 may indicate a time span in which a reference signal 410 measured by the UE in the idle/inactive state (e.g., reference signal 410-c) is still valid or has not varied from a reference signal that the UE measured in the Uu connected state (e.g., reference signal 410-a or reference signal 410-b) . When UE determines that a reference signal 410 measured by the UE in the idle/inactive state is still valid or has not varied, UE may determine that a configuration associated with the measured reference signal 410 is still valid or has not varied from a configuration associated with a reference signal that the UE measured in the Uu connected state (e.g., reference signal 410-a or reference signal 410-b) . However, UE may determine that a reference signal 410 measured by the UE in the idle/inactive state after time period 425 has ended (e.g., reference signal 410-n) is no longer valid or varies from a reference signal that the UE measured in the Uu connected state (e.g., reference signal 410-a or reference signal 410-b) . When the UE determines that the time period 425 has expired (e.g., upon determining that the timer has expired or elapsed) , the UE may determine that a previous configuration received while the UE was in the Uu connected state is no longer valid.

When UE determines that the reference signal 410 measured by the UE in the idle/inactive state after time period 425 has ended is no longer valid, the UE may perform one or more operations to estimate transmit timing information (e.g., Uu uplink transmit timing advance) associated with the one or more uplink transmissions transmitted by another UE (e.g., a sidelink UE) .

In some cases, when UE determines that a previous configuration is no longer valid based on the expiration of time period 425, the UE may request an updated configuration. In some cases, the UE may compare a received configuration to a previous configuration that the UE received prior to entering the idle/inactive state (e.g., during Uu connected time span 415) . In some cases, the UE may determine whether the received configuration differs from the previous configuration. In some cases, the UE may estimate transmit timing information (e.g., Uu uplink transmit timing advance) based on the UE determining the configurations do not match.

FIG. 5 illustrates an example of a process flow 500 that supports timing advance acquisition techniques for sidelink in accordance with aspects of the present disclosure. As illustrated, process flow 500 may include UE 115-e, UE 115-f, and base station 105-c, any of which may be an example of a UE 115 or a base station 105, respectively, as described above with reference to FIGs. 1 through 4. In some cases, UE 115-e may be in an inactive state or an idle state of a Uu connection between UE 115-e and base station 105-c. In some cases, UE 115-f may be in an Uu connected state with base station 105-c. In some cases, a sidelink connection may exist between UE 115-e and UE 115-f.

At 505, base station 105-c may transmit a configuration to UE 115-f (e.g., a Uu inter-UE signal configuration, crosslink interference configuration, etc. ) .

At 510, UE 115-f may transmit the configuration received at 505 to UE 115-e. In some cases, UE 115-f may transmit the configuration over a sidelink connection (e.g., over a PC5 interface using PC5 signaling) between UE 115-f and UE 115-e.

At 515, UE 115-f may transmit an uplink transmission, for example to a base station serving UE 115-f. In some cases, the uplink transmission may include a Uu transmission.

At 520, based on the configuration received at 510, UE 115-e may perform a measurement procedure with respect to the uplink transmission of UE 115-f at 515.

At 525, UE 115-e may determine timing information associated with the uplink transmission of UE 115-f at 515. In some cases, the configuration of 505 may include a resource configuration for UE 115-f to measure its own crosslink interference. Accordingly, when UE 115-f sends the configuration of 505 to UE 115-e, UE 115-e may use the same configuration of 505 to estimate timing information (e.g., Uu uplink transmit timing advance of a Uu connection between UE 115-f and base station 105-c) based on the crosslink interference measured by UE 115-e via the received configuration.

At 530, UE 115-e may use the determined timing information to communicate with UE 115-f over the sidelink connection.

FIG. 6 illustrates an example of a process flow 600 that supports timing advance acquisition techniques for sidelink in accordance with aspects of the present disclosure. As illustrated, process flow 600 may include UE 115-g and UE 115-h, any of which may be an example of a UE 115, respectively, as described above with reference to FIGs. 1 through 5. In some cases, UE 115-g may be in an Uu idle/inactive state (e.g., of a Uu connection between UE 115-g and a base station) . In some cases, UE 115-h may be in an Uu connected state with a base station. In some cases, a sidelink connection may exist between UE 115-g and UE 115-h.

At 605, UE 115-h may transmit a configuration (e.g., uplink transmission configuration, sounding reference signal configuration, demodulation reference signal configuration) to UE 115-g. In some cases, UE 115-h may transmit the configuration over a sidelink connection (e.g., over a PC5 interface) between UE 115-h and UE 115-g.

At 610, UE 115-h may transmit an uplink transmission, for example to the base station serving UE 115-h. In some cases, the uplink transmission may include a Uu uplink transmission.

At 615, based on the configuration received at 605 UE 115-g may perform a measurement procedure with respect to the uplink transmission of UE 115-h at 610.

At 620, UE 115-g may determine timing information associated with the uplink transmission of UE 115-h at 610. In some cases, the configuration of 605 may include a reference signal configuration for UE 115-h. Accordingly, when UE 115-h sends the configuration to UE 115-g, UE 115-g may use the same configuration of 605 to estimate timing information (e.g., Uu uplink transmit timing advance of an uplink transmission of UE 115-h) based on the crosslink interference measured by UE 115-g via the received configuration.

At 625, UE 115-g may use the determined timing information to communicate with UE 115-h over the sidelink connection.

FIG. 7 illustrates an example of a process flow 700 that supports timing advance acquisition techniques for sidelink in accordance with aspects of the present disclosure. As illustrated, process flow 700 may include UE 115-j and base station 105-d, any of which may be an example of a UE 115 or base station 105, respectively, as described above with reference to FIGs. 1 through 6.

At 705, base station 105-d may transmit a configuration (e.g., sounding reference signal configuration, demodulation reference signal configuration, sounding reference signal configuration measured between inter-UE UEs, or other configuration associated with the transmission of reference signals, including uplink reference signals) to UE 115-j. In some cases, base station 105-d may transmit the configuration via a system information block (SIB) , for example as part of an existing SIB type (e.g., any one or more of SIB1, SIB2, SIB3, through at least SIB14) or using a SIB type defined for the purpose of transmitting configuration information as described herein. In some cases, base station 105-d may broadcast the configuration in the system information block. The base station broadcasting the configuration in the system information block may be based on multiple UEs (e.g., including UE 115-j) being configured with the same sounding reference signal configuration, or with the same set of sounding reference signal configurations in different time occasions, or received by different receive beams.

At 710, an adjacent UE may transmit an uplink transmission. In some cases, the uplink transmission may include a Uu uplink transmission, for example to a base station serving the adjacent UE.

At 715, based on the configuration received at 705, UE 115-j may perform a measurement procedure with respect to the uplink transmission at 710.

At 720, UE 115-j may determine timing information associated with the uplink transmission at 710. In some cases, the configuration of 705 may include a reference signal configuration. Accordingly, when base station 105-d sends the configuration to UE 115-j, UE 115-j may use the same configuration of 705 to estimate timing information (e.g., Uu uplink transmit timing advance of uplink transmission at 710) based on the crosslink interference measured by UE 115-j via the received configuration. In some cases, the information in the system information block at 705 may enable UE 115-j to determine where and when to measure the sounding reference signal to determine the timing information (e.g., Uu uplink transmit timing advance) .

At 725, UE 115-j may use the determined timing information to communicate with a relatively nearby UE over a sidelink connection. Accordingly, UE 115-j may use the configuration received at 705 to mitigate interference while communicating over the sidelink.

FIG. 8 shows a block diagram 800 of a device 805 that supports timing advance acquisition techniques for sidelink in accordance with aspects of the present disclosure. The device 805 may be an example of aspects of a UE 115 as described herein. The device 805 may include a receiver 810, a transmitter 815, and a communications manager 820. The device 805 may also include a processor. Each of these components may be in communication with one another (e.g., via one or more buses) .

The receiver 810 may provide a means for receiving information such as packets, user data, control information, or any combination thereof associated with various information channels (e.g., control channels, data channels, information channels related to timing advance acquisition techniques for sidelink) . Information may be passed on to other components of the device 805. The receiver 810 may utilize a single antenna or a set of multiple antennas.

The transmitter 815 may provide a means for transmitting signals generated by other components of the device 805. For example, the transmitter 815 may transmit information such as packets, user data, control information, or any combination thereof associated with various information channels (e.g., control channels, data channels, information channels related to timing advance acquisition techniques for sidelink) . In some examples, the transmitter 815 may be co-located with a receiver 810 in a transceiver module. The transmitter 815 may utilize a single antenna or a set of multiple antennas.

The communications manager 820, the receiver 810, the transmitter 815, or various combinations thereof or various components thereof may be examples of means for performing various aspects of timing advance acquisition techniques for sidelink as described herein. For example, the communications manager 820, the receiver 810, the transmitter 815, or various combinations or components thereof may support a method for performing one or more of the functions described herein.

In some examples, the communications manager 820, the receiver 810, the transmitter 815, or various combinations or components thereof may be implemented in hardware (e.g., in communications management circuitry) . The hardware may include a processor, a digital signal processor (DSP) , an application-specific integrated circuit (ASIC) , a field-programmable gate array (FPGA) or other programmable logic device, a discrete gate or transistor logic, discrete hardware components, or any combination thereof configured as or otherwise supporting a means for performing the functions described in the present disclosure. In some examples, a processor and memory coupled with the processor may be configured to perform one or more of the functions described herein (e.g., by executing, by the processor, instructions stored in the memory) .

Additionally or alternatively, in some examples, the communications manager 820, the receiver 810, the transmitter 815, or various combinations or components thereof may be implemented in code (e.g., as communications management software or firmware) executed by a processor. If implemented in code executed by a processor, the functions of the communications manager 820, the receiver 810, the transmitter 815, or various combinations or components thereof may be performed by a general-purpose processor, a DSP, a central processing unit (CPU) , an ASIC, an FPGA, or any combination of these or other programmable logic devices (e.g., configured as or otherwise supporting a means for performing the functions described in the present disclosure) .

In some examples, the communications manager 820 may be configured to perform various operations (e.g., receiving, monitoring, transmitting) using or otherwise in cooperation with the receiver 810, the transmitter 815, or both. For example, the communications manager 820 may receive information from the receiver 810, send information to the transmitter 815, or be integrated in combination with the receiver 810, the transmitter 815, or both to receive information, transmit information, or perform various other operations as described herein.

The communications manager 820 may support wireless communication at a first UE in accordance with examples as disclosed herein. For example, the communications manager 820 may be configured as or otherwise support a means for receiving a configuration that indicates resources for the first UE to use to perform, in an inactive state or an idle state of a wireless connection of the first UE and a base station, a measurement procedure on reference signals transmitted by one or more UEs. The communications manager 820 may be configured as or otherwise support a means for receiving, in the inactive state or the idle state, the reference signals on the resources indicated by the configuration. The communications manager 820 may be configured as or otherwise support a means for determining a timing advance value for uplink communications with the base station based on the first UE performing the measurement procedure on the received reference signals. The communications manager 820 may be configured as or otherwise support a means for communicating, in the inactive or idle state for the wireless connection with the base station, on a sidelink connection with a second UE according to the determined timing advance value for the uplink communications with the base station.

By including or configuring the communications manager 820 in accordance with examples as described herein, the device 805 (e.g., a processor controlling or otherwise coupled to the receiver 810, the transmitter 815, the communications manager 820, or a combination thereof) may support techniques for improvements in system efficiency such that device 805 may minimize crosslink interference by determining a timing advance configuration of a Uu configuration that device 805 receives from an external device (e.g., from a base station 105, from a UE 115, etc. ) . Additionally, described techniques may result in device 805 avoiding multiple retransmissions and failed transmissions, decreasing system latency, improving the reliability of a decoding procedure for received uplink transmissions at a base station 105, and improving user experience.

FIG. 9 shows a block diagram 900 of a device 905 that supports timing advance acquisition techniques for sidelink in accordance with aspects of the present disclosure. The device 905 may be an example of aspects of a device 805 or a UE 115 as described herein. The device 905 may include a receiver 910, a transmitter 915, and a communications manager 920. The device 905 may also include a processor. Each of these components may be in communication with one another (e.g., via one or more buses) .

The receiver 910 may provide a means for receiving information such as packets, user data, control information, or any combination thereof associated with various information channels (e.g., control channels, data channels, information channels related to timing advance acquisition techniques for sidelink) . Information may be passed on to other components of the device 905. The receiver 910 may utilize a single antenna or a set of multiple antennas.

The transmitter 915 may provide a means for transmitting signals generated by other components of the device 905. For example, the transmitter 915 may transmit information such as packets, user data, control information, or any combination thereof associated with various information channels (e.g., control channels, data channels, information channels related to timing advance acquisition techniques for sidelink) . In some examples, the transmitter 915 may be co-located with a receiver 910 in a transceiver module. The transmitter 915 may utilize a single antenna or a set of multiple antennas.

The device 905, or various components thereof, may be an example of means for performing various aspects of timing advance acquisition techniques for sidelink as described herein. For example, the communications manager 920 may include a configuration manager 925, a measurement manager 930, a timing manager 935, a sidelink manager 940, or any combination thereof. The communications manager 920 may be an example of aspects of a communications manager 820 as described herein. In some examples, the communications manager 920, or various components thereof, may be configured to perform various operations (e.g., receiving, monitoring, transmitting) using or otherwise in cooperation with the receiver 910, the transmitter 915, or both. For example, the communications manager 920 may receive information from the receiver 910, send information to the transmitter 915, or be integrated in combination with the receiver 910, the transmitter 915, or both to receive information, transmit information, or perform various other operations as described herein.

The communications manager 920 may support wireless communication at a first UE in accordance with examples as disclosed herein. The configuration manager 925 may be configured as or otherwise support a means for receiving a configuration that indicates resources for the first UE to use to perform, in an inactive state or an idle state of a wireless connection of the first UE and a base station, a measurement procedure on reference signals transmitted by one or more UEs. The measurement manager 930 may be configured as or otherwise support a means for receiving, in the inactive state or the idle state, the reference signals on the resources indicated by the configuration. The timing manager 935 may be configured as or otherwise support a means for determining a timing advance value for uplink communications with the base station based on the first UE performing the measurement procedure on the received reference signals. The sidelink manager 940 may be configured as or otherwise support a means for communicating, in the inactive or idle state for the wireless connection with the base station, on a sidelink connection with a second UE according to the determined timing advance value for the uplink communications with the base station.

FIG. 10 shows a block diagram 1000 of a communications manager 1020 that supports timing advance acquisition techniques for sidelink in accordance with aspects of the present disclosure. The communications manager 1020 may be an example of aspects of a communications manager 820, a communications manager 920, or both, as described herein. The communications manager 1020, or various components thereof, may be an example of means for performing various aspects of timing advance acquisition techniques for sidelink as described herein. For example, the communications manager 1020 may include a configuration manager 1025, a measurement manager 1030, a timing manager 1035, a sidelink manager 1040, a capability manager 1045, or any combination thereof. Each of these components may communicate, directly or indirectly, with one another (e.g., via one or more buses) .

The communications manager 1020 may support wireless communication at a first UE in accordance with examples as disclosed herein. The configuration manager 1025 may be configured as or otherwise support a means for receiving a configuration that indicates resources for the first UE to use to perform, in an inactive state or an idle state of a wireless connection of the first UE and a base station, a measurement procedure on reference signals transmitted by one or more UEs. The measurement manager 1030 may be configured as or otherwise support a means for receiving, in the inactive state or the idle state, the reference signals on the resources indicated by the configuration. The timing manager 1035 may be configured as or otherwise support a means for determining a timing advance value for uplink communications with the base station based on the first UE performing the measurement procedure on the received reference signals. The sidelink manager 1040 may be configured as or otherwise support a means for communicating, in the inactive or idle state for the wireless connection with the base station, on a sidelink connection with a second UE according to the determined timing advance value for the uplink communications with the base station.

In some examples, the measurement manager 1030 may be configured as or otherwise support a means for performing the measurement procedure on the reference signals on the resources during an active state of the wireless connection of the first UE and the base station, where the received configuration further indicates for the first UE to continue to perform the measurement procedure on the reference signals on the resources indicated by the configuration for a time duration.

In some examples, the configuration is signaled to the first UE via radio resource control signaling or PC5 interface signaling. In some examples, to support receiving the configuration, the configuration manager 1025 may be configured as or otherwise support a means for receiving a broadcast of system information that identifies the configuration. In some examples, to support receiving the configuration, the configuration manager 1025 may be configured as or otherwise support a means for receiving the configuration from the second UE over the sidelink connection or from a third UE over a different sidelink connection.

In some examples, the configuration identifies resources configured for the second UE or the third UE to use to measure cross link interference at a respective one of the second UE or the third UE. In some examples, the configuration identifies resources configured for the second UE or the third UE to use to transmit uplink reference signals. In some examples, the uplink reference signals include sounding reference signals or demodulation reference signals.

In some examples, the capability manager 1045 may be configured as or otherwise support a means for transmitting, to the base station, an indication of a capability of the first UE to perform a sidelink timing advance acquisition procedure to determine, in the inactive state or the idle state, a timing advance value for the sidelink connection that corresponds to the wireless connection with the base station, where the configuration is received in accordance with the first UE transmitting the indication of the capability to the base station.

In some examples, the configuration manager 1025 may be configured as or otherwise support a means for receiving, from the base station, a timing indicator that identifies a time of an expiration of the configuration. In some examples, to support receiving the configuration, the configuration manager 1025 may be configured as or otherwise support a means for determining that the configuration is expired based on the timing indicator. In some examples, to support receiving the configuration, the configuration manager 1025 may be configured as or otherwise support a means for requesting an updated configuration in response to determining that the configuration is expired.

In some examples, to support receiving the configuration, the configuration manager 1025 may be configured as or otherwise support a means for comparing the received configuration to a previous configuration the first UE received prior to entering the inactive state or the idle state. In some examples, to support receiving the configuration, the configuration manager 1025 may be configured as or otherwise support a means for determining whether the received configuration differs from the previous configuration, where the determining of the timing advance value for uplink communications with the base station based on the first UE performing the measurement procedure on the received reference signals is based on a determination that the received configuration differs from the previous configuration.

FIG. 11 shows a diagram of a system 1100 including a device 1105 that supports timing advance acquisition techniques for sidelink in accordance with aspects of the present disclosure. The device 1105 may be an example of or include the components of a device 805, a device 905, or a UE 115 as described herein. The device 1105 may communicate wirelessly with one or more base stations 105, UEs 115, or any combination thereof. The device 1105 may include components for bi-directional voice and data communications including components for transmitting and receiving communications, such as a communications manager 1120, an input/output (I/O) controller 1110, a transceiver 1115, an antenna 1125, a memory 1130, code 1135, and a processor 1140. These components may be in electronic communication or otherwise coupled (e.g., operatively, communicatively, functionally, electronically, electrically) via one or more buses (e.g., a bus 1145) .

The I/O controller 1110 may manage input and output signals for the device 1105. The I/O controller 1110 may also manage peripherals not integrated into the device 1105. In some cases, the I/O controller 1110 may represent a physical connection or port to an external peripheral. In some cases, the I/O controller 1110 may utilize an operating system such as

or another known operating system. Additionally or alternatively, the I/O controller 1110 may represent or interact with a modem, a keyboard, a mouse, a touchscreen, or a similar device. In some cases, the I/O controller 1110 may be implemented as part of a processor, such as the processor 1140. In some cases, a user may interact with the device 1105 via the I/O controller 1110 or via hardware components controlled by the I/O controller 1110.

In some cases, the device 1105 may include a single antenna 1125. However, in some other cases, the device 1105 may have more than one antenna 1125, which may be capable of concurrently transmitting or receiving multiple wireless transmissions. The transceiver 1115 may communicate bi-directionally, via the one or more antennas 1125, wired, or wireless links as described herein. For example, the transceiver 1115 may represent a wireless transceiver and may communicate bi-directionally with another wireless transceiver. The transceiver 1115 may also include a modem to modulate the packets, to provide the modulated packets to one or more antennas 1125 for transmission, and to demodulate packets received from the one or more antennas 1125. The transceiver 1115, or the transceiver 1115 and one or more antennas 1125, may be an example of a transmitter 815, a transmitter 915, a receiver 810, a receiver 910, or any combination thereof or component thereof, as described herein.

The memory 1130 may include random access memory (RAM) and read-only memory (ROM) . The memory 1130 may store computer-readable, computer-executable code 1135 including instructions that, when executed by the processor 1140, cause the device 1105 to perform various functions described herein. The code 1135 may be stored in a non-transitory computer-readable medium such as system memory or another type of memory. In some cases, the code 1135 may not be directly executable by the processor 1140 but may cause a computer (e.g., when compiled and executed) to perform functions described herein. In some cases, the memory 1130 may contain, among other things, a basic I/O system (BIOS) which may control basic hardware or software operation such as the interaction with peripheral components or devices.

The processor 1140 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 1140 may be configured to operate a memory array using a memory controller. In some other cases, a memory controller may be integrated into the processor 1140. The processor 1140 may be configured to execute computer-readable instructions stored in a memory (e.g., the memory 1130) to cause the device 1105 to perform various functions (e.g., functions or tasks supporting timing advance acquisition techniques for sidelink) . For example, the device 1105 or a component of the device 1105 may include a processor 1140 and memory 1130 coupled to the processor 1140, the processor 1140 and memory 1130 configured to perform various functions described herein.

The communications manager 1120 may support wireless communication at a first UE in accordance with examples as disclosed herein. For example, the communications manager 1120 may be configured as or otherwise support a means for receiving a configuration that indicates resources for the first UE to use to perform, in an inactive state or an idle state of a wireless connection of the first UE and a base station, a measurement procedure on reference signals transmitted by one or more UEs. The communications manager 1120 may be configured as or otherwise support a means for receiving, in the inactive state or the idle state, the reference signals on the resources indicated by the configuration. The communications manager 1120 may be configured as or otherwise support a means for determining a timing advance value for uplink communications with the base station based on the first UE performing the measurement procedure on the received reference signals. The communications manager 1120 may be configured as or otherwise support a means for communicating, in the inactive or idle state for the wireless connection with the base station, on a sidelink connection with a second UE according to the determined timing advance value for the uplink communications with the base station.

By including or configuring the communications manager 1120 in accordance with examples as described herein, the device 1105 may support techniques for improvements in system efficiency such that device 1105 may minimize crosslink interference by determining a timing advance configuration of a Uu configuration that device 1105 receives from an external device (e.g., from a base station 105, from a UE 115, etc. ) . Additionally, described techniques may result in device 1105 avoiding multiple retransmissions and failed transmissions, decreasing system latency, improving the reliability of a decoding procedure for received uplink transmissions at a base station 105, and improving user experience.

In some examples, the communications manager 1120 may be configured to perform various operations (e.g., receiving, monitoring, transmitting) using or otherwise in cooperation with the transceiver 1115, the one or more antennas 1125, or any combination thereof. Although the communications manager 1120 is illustrated as a separate component, in some examples, one or more functions described with reference to the communications manager 1120 may be supported by or performed by the processor 1140, the memory 1130, the code 1135, or any combination thereof. For example, the code 1135 may include instructions executable by the processor 1140 to cause the device 1105 to perform various aspects of timing advance acquisition techniques for sidelink as described herein, or the processor 1140 and the memory 1130 may be otherwise configured to perform or support such operations.

FIG. 12 shows a flowchart illustrating a method 1200 that supports timing advance acquisition techniques for sidelink in accordance with aspects of the present disclosure. The operations of the method 1200 may be implemented by a UE or its components as described herein. For example, the operations of the method 1200 may be performed by a UE 115 as described with reference to FIGs. 1 through 11. In some examples, a UE may execute a set of instructions to control the functional elements of the UE to perform the described functions. Additionally or alternatively, the UE may perform aspects of the described functions using special-purpose hardware.

At 1205, the method may include receiving a configuration that indicates resources for the first UE to use to perform, in an inactive state or an idle state of a wireless connection of the first UE and a base station, a measurement procedure on reference signals transmitted by one or more UEs. The operations of 1205 may be performed in accordance with examples as disclosed herein. In some examples, aspects of the operations of 1205 may be performed by a configuration manager 1025 as described with reference to FIG. 10.

At 1210, the method may include receiving, in the inactive state or the idle state, the reference signals on the resources indicated by the configuration. The operations of 1210 may be performed in accordance with examples as disclosed herein. In some examples, aspects of the operations of 1210 may be performed by a measurement manager 1030 as described with reference to FIG. 10.

At 1215, the method may include determining a timing advance value for uplink communications with the base station based on the first UE performing the measurement procedure on the received reference signals. The operations of 1215 may be performed in accordance with examples as disclosed herein. In some examples, aspects of the operations of 1215 may be performed by a timing manager 1035 as described with reference to FIG. 10.

At 1220, the method may include communicating, in the inactive or idle state for the wireless connection with the base station, on a sidelink connection with a second UE according to the determined timing advance value for the uplink communications with the base station. The operations of 1220 may be performed in accordance with examples as disclosed herein. In some examples, aspects of the operations of 1220 may be performed by a sidelink manager 1040 as described with reference to FIG. 10.

FIG. 13 shows a flowchart illustrating a method 1300 that supports timing advance acquisition techniques for sidelink in accordance with aspects of the present disclosure. The operations of the method 1300 may be implemented by a UE or its components as described herein. For example, the operations of the method 1300 may be performed by a UE 115 as described with reference to FIGs. 1 through 11. In some examples, a UE may execute a set of instructions to control the functional elements of the UE to perform the described functions. Additionally or alternatively, the UE may perform aspects of the described functions using special-purpose hardware.

At 1305, the method may include receiving a configuration that indicates resources for the first UE to use to perform, in an inactive state or an idle state of a wireless connection of the first UE and a base station, a measurement procedure on reference signals transmitted by one or more UEs. The operations of 1305 may be performed in accordance with examples as disclosed herein. In some examples, aspects of the operations of 1305 may be performed by a configuration manager 1025 as described with reference to FIG. 10.

At 1310, the method may include receiving, in the inactive state or the idle state, the reference signals on the resources indicated by the configuration. The operations of 1310 may be performed in accordance with examples as disclosed herein. In some examples, aspects of the operations of 1310 may be performed by a measurement manager 1030 as described with reference to FIG. 10.

At 1315, the method may include determining a timing advance value for uplink communications with the base station based on the first UE performing the measurement procedure on the received reference signals. The operations of 1315 may be performed in accordance with examples as disclosed herein. In some examples, aspects of the operations of 1315 may be performed by a timing manager 1035 as described with reference to FIG. 10.

At 1320, the method may include communicating, in the inactive or idle state for the wireless connection with the base station, on a sidelink connection with a second UE according to the determined timing advance value for the uplink communications with the base station. The operations of 1320 may be performed in accordance with examples as disclosed herein. In some examples, aspects of the operations of 1320 may be performed by a sidelink manager 1040 as described with reference to FIG. 10.

At 1325, the method may include performing the measurement procedure on the reference signals on the resources during an active state of the wireless connection of the first UE and the base station, where the received configuration further indicates for the first UE to continue to perform the measurement procedure on the reference signals on the resources indicated by the configuration for a time duration. The operations of 1325 may be performed in accordance with examples as disclosed herein. In some examples, aspects of the operations of 1325 may be performed by a measurement manager 1030 as described with reference to FIG. 10.

The following provides an overview of aspects of the present disclosure:

Aspect 1: A method for wireless communication at a first UE, comprising: receiving a configuration that indicates resources for the first UE to use to perform, in an inactive state or an idle state of a wireless connection of the first UE and a base station, a measurement procedure on reference signals transmitted by one or more UEs; receiving, in the inactive state or the idle state, the reference signals on the resources indicated by the configuration; determining a timing advance value for uplink communications with the base station based at least in part on the first UE performing the measurement procedure on the received reference signals; and communicating, in the inactive or idle state for the wireless connection with the base station, on a sidelink connection with a second UE according to the determined timing advance value for the uplink communications with the base station.

Aspect 2: The method of aspect 1, further comprising: performing the measurement procedure on the reference signals on the resources during an active state of the wireless connection of the first UE and the base station, wherein the received configuration further indicates for the first UE to continue to perform the measurement procedure on the reference signals on the resources indicated by the configuration for a time duration.

Aspect 3: The method of any of aspects 1 through 2, wherein receiving the configuration comprises: receiving a broadcast of system information that identifies the configuration.

Aspect 4: The method of any of aspects 1 through 3, wherein receiving the configuration comprises: receiving the configuration from the second UE over the sidelink connection or from a third UE over a different sidelink connection.

Aspect 5: The method of aspect 4, wherein the configuration identifies resources configured for the second UE or the third UE to use to measure cross link interference at a respective one of the second UE or the third UE.

Aspect 6: The method of any of aspects 4 through 5, wherein the configuration identifies resources configured for the second UE or the third UE to use to transmit uplink reference signals.

Aspect 7: The method of aspect 6, wherein the uplink reference signals comprise sounding reference signals or demodulation reference signals.

Aspect 8: The method of any of aspects 1 through 7, further comprising: transmitting, to the base station, an indication of a capability of the first UE to perform a sidelink timing advance acquisition procedure to determine, in the inactive state or the idle state, a timing advance value for the sidelink connection that corresponds to the wireless connection with the base station, wherein the configuration is received in accordance with the first UE transmitting the indication of the capability to the base station.

Aspect 9: The method of any of aspects 1 through 8, wherein the configuration is signaled to the first UE via radio resource control signaling or PC5 interface signaling.

Aspect 10: The method of any of aspects 1 through 9, further comprising: receiving, from the base station, a timing indicator that identifies a time of an expiration of the configuration.

Aspect 11: The method of aspect 10, wherein receiving the configuration further comprises: determining that the configuration is expired based at least in part on the timing indicator; and requesting an updated configuration in response to determining that the configuration is expired.

Aspect 12: The method of any of aspects 10 through 11, wherein receiving the configuration further comprises: comparing the received configuration to a previous configuration the first UE received prior to entering the inactive state or the idle state; and determining whether the received configuration differs from the previous configuration, wherein the determining of the timing advance value for uplink communications with the base station based at least in part on the first UE performing the measurement procedure on the received reference signals is based at least in part on a determination that the received configuration differs from the previous configuration.

Aspect 13: An apparatus for wireless communication at a first UE, comprising a processor; memory coupled with the processor; and instructions stored in the memory and executable by the processor to cause the apparatus to perform a method of any of aspects 1 through 12.

Aspect 14: An apparatus for wireless communication at a first UE, comprising at least one means for performing a method of any of aspects 1 through 12.

Aspect 15: A non-transitory computer-readable medium storing code for wireless communication at a first UE, the code comprising instructions executable by a processor to perform a method of any of aspects 1 through 12.

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

Although aspects of an LTE, LTE-A, LTE-A Pro, or NR system may be described for purposes of example, and LTE, LTE-A, LTE-A Pro, or NR terminology may be used in much of the description, the techniques described herein are applicable beyond LTE, LTE-A, LTE-A Pro, or NR networks. For example, the described techniques may be applicable to various other wireless communications systems such as Ultra Mobile Broadband (UMB) , Institute of Electrical and Electronics Engineers (IEEE) 802.11 (Wi-Fi) , IEEE 802.16 (WiMAX) , IEEE 802.20, Flash-OFDM, as well as other systems and radio technologies not explicitly mentioned herein.

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 referenced throughout the description may be represented by voltages, currents, electromagnetic waves, magnetic fields or particles, optical fields or particles, or any combination thereof.

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

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 transmitted over as one or more instructions or code on a computer-readable medium. Other examples and implementations are within the scope of the disclosure and appended claims. For example, due to the nature of software, functions described herein may be implemented using software executed by a processor, hardware, firmware, hardwiring, or combinations of any of these. Features implementing functions may also be physically located at various positions, including being distributed such that portions of functions are implemented at different physical locations.

Computer-readable media includes both non-transitory computer storage media and communication media including any medium that facilitates transfer of a computer program from one place to another. A non-transitory storage medium may be any available medium that may be accessed by a general-purpose or special-purpose computer. By way of example, and not limitation, non-transitory computer-readable media may include RAM, ROM, electrically erasable programmable ROM (EEPROM) , flash memory, compact disk (CD) ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other non-transitory medium that may be used to carry or store desired program code means in the form of instructions or data structures and that may be accessed by a general-purpose or special-purpose computer, or a general-purpose or special-purpose processor. Also, any connection is properly termed a computer-readable medium. For example, if the software is transmitted from a website, server, or other remote source using a coaxial cable, fiber optic cable, twisted pair, digital subscriber line (DSL) , or wireless technologies such as infrared, radio, and microwave, then the coaxial cable, fiber optic cable, twisted pair, DSL, or wireless technologies such as infrared, radio, and microwave are included in the definition of computer-readable medium. Disk and disc, as used herein, include CD, laser disc, optical disc, digital versatile disc (DVD) , floppy disk and Blu-ray disc where disks usually reproduce data magnetically, while discs reproduce data optically with lasers. Combinations of the above are also included within the scope of computer-readable media.

As used herein, including in the claims, “or” as used in a list of items (e.g., a list of items prefaced by a phrase such as “at least one of” or “one or more of” ) indicates an inclusive list such that, for example, a list of at least one of A, B, or C means A or B or C or AB or AC or BC or ABC (i.e., A and B and C) . Also, as used herein, the phrase “based on” shall not be construed as a reference to a closed set of conditions. For example, an example step that is described as “based on condition A” may be based on both a condition A and a condition B without departing from the scope of the present disclosure. In other words, as used herein, the phrase “based on” shall be construed in the same manner as the phrase “based at least in part on. ”

In the appended figures, similar components or features may have the same reference label. Further, various components of the same type may be distinguished by following the reference label by a dash and a second label that distinguishes among the similar components. If just the first reference label is used in the specification, the description is applicable to any one of the similar components having the same first reference label irrespective of the second reference label, or other subsequent reference label.

The description set forth herein, in connection with the appended drawings, describes example configurations and does not represent all the examples that may be implemented or that are within the scope of the claims. The term “example” used herein means “serving as an example, instance, or illustration, ” and not “preferred” or “advantageous over other examples. ” The detailed description includes specific details for the purpose of providing an understanding of the described techniques. These techniques, however, may be practiced without these specific details. In some instances, known structures and devices are shown in block diagram form in order to avoid obscuring the concepts of the described examples.

The description herein is provided to enable a person having ordinary skill in the art to make or use the disclosure. Various modifications to the disclosure will be apparent to a person having ordinary skill in the art, and the generic principles defined herein may be applied to other variations without departing from the scope of the disclosure. Thus, the disclosure is not limited to the examples and designs described herein but is to be accorded the broadest scope consistent with the principles and novel features disclosed herein.

Claims

A method for wireless communication at a first user equipment (UE) , comprising:

receiving a configuration that indicates resources for the first UE to use to perform, in an inactive state or an idle state of a wireless connection of the first UE and a base station, a measurement procedure on reference signals transmitted by one or more UEs;

receiving, in the inactive state or the idle state, the reference signals on the resources indicated by the configuration;

determining a timing advance value for uplink communications with the base station based at least in part on the first UE performing the measurement procedure on the received reference signals; and

communicating, in the inactive or idle state for the wireless connection with the base station, on a sidelink connection with a second UE according to the determined timing advance value for the uplink communications with the base station.
The method of claim 1, further comprising:

performing the measurement procedure on the reference signals on the resources during an active state of the wireless connection of the first UE and the base station, wherein the received configuration further indicates for the first UE to continue to perform the measurement procedure on the reference signals on the resources indicated by the configuration for a time duration.
The method of claim 1, wherein receiving the configuration comprises:

receiving a broadcast of system information that identifies the configuration.
The method of claim 1, wherein receiving the configuration comprises:

receiving the configuration from the second UE over the sidelink connection or from a third UE over a different sidelink connection.
The method of claim 4, wherein the configuration identifies resources configured for the second UE or the third UE to use to measure cross link interference at a respective one of the second UE or the third UE.
The method of claim 4, wherein the configuration identifies resources configured for the second UE or the third UE to use to transmit uplink reference signals.
The method of claim 6, wherein the uplink reference signals comprise sounding reference signals or demodulation reference signals.
The method of claim 1, further comprising:

transmitting, to the base station, an indication of a capability of the first UE to perform a sidelink timing advance acquisition procedure to determine, in the inactive state or the idle state, a timing advance value for the sidelink connection that corresponds to the wireless connection with the base station, wherein the configuration is received in accordance with the first UE transmitting the indication of the capability to the base station.
The method of claim 1, wherein the configuration is signaled to the first UE via radio resource control signaling or PC5 interface signaling.
The method of claim 1, further comprising:

receiving, from the base station, a timing indicator that identifies a time of an expiration of the configuration.
The method of claim 10, wherein receiving the configuration further comprises:

determining that the configuration is expired based at least in part on the timing indicator; and

requesting an updated configuration in response to determining that the configuration is expired.
The method of claim 10, wherein receiving the configuration further comprises:

comparing the received configuration to a previous configuration the first UE received prior to entering the inactive state or the idle state; and

determining whether the received configuration differs from the previous configuration, wherein the determining of the timing advance value for uplink communications with the base station based at least in part on the first UE performing the measurement procedure on the received reference signals is based at least in part on a determination that the received configuration differs from the previous configuration.
An apparatus for wireless communication at a first user equipment (UE) , comprising:

a processor;

memory coupled with the processor; and

instructions stored in the memory and executable by the processor to cause the apparatus to:

receive a configuration that indicates resources for the first UE to use to perform, in an inactive state or an idle state of a wireless connection of the first UE and a base station, a measurement procedure on reference signals transmitted by one or more UEs;

receive, in the inactive state or the idle state, the reference signals on the resources indicated by the configuration;

determine a timing advance value for uplink communications with the base station based at least in part on the first UE performing the measurement procedure on the received reference signals; and

communicate, in the inactive or idle state for the wireless connection with the base station, on a sidelink connection with a second UE according to the determined timing advance value for the uplink communications with the base station.
The apparatus of claim 13, wherein the instructions are further executable by the processor to cause the apparatus to:

perform the measurement procedure on the reference signals on the resources during an active state of the wireless connection of the first UE and the base station, wherein the received configuration further indicates for the first UE to continue to perform the measurement procedure on the reference signals on the resources indicated by the configuration for a time duration.
The apparatus of claim 13, further comprising a receiver, and wherein the instructions to receive the configuration are executable by the processor to cause the apparatus to:

receive, using the receiver, a broadcast of system information that identifies the configuration.
The apparatus of claim 13, further comprising a receiver, and wherein the instructions to receive the configuration are executable by the processor to cause the apparatus to:

receive, using the receiver, the configuration from the second UE over the sidelink connection or from a third UE over a different sidelink connection.
The apparatus of claim 16, wherein the configuration identifies resources configured for the second UE or the third UE to use to measure cross link interference at a respective one of the second UE or the third UE.
The apparatus of claim 16, wherein the configuration identifies resources configured for the second UE or the third UE to use to transmit uplink reference signals.
The apparatus of claim 18, wherein the uplink reference signals comprise sounding reference signals or demodulation reference signals.
The apparatus of claim 13, further comprising a transmitter, and wherein the instructions are further executable by the processor to cause the apparatus to:

transmit, to the base station using the transmitter, an indication of a capability of the first UE to perform a sidelink timing advance acquisition procedure to determine, in the inactive state or the idle state, a timing advance value for the sidelink connection that corresponds to the wireless connection with the base station, wherein the configuration is received in accordance with the first UE transmitting the indication of the capability to the base station.
The apparatus of claim 13, wherein the configuration is signaled to the first UE via radio resource control signaling or PC5 interface signaling.
The apparatus of claim 13, further comprising a receiver, and wherein the instructions are further executable by the processor to cause the apparatus to:

receive, from the base station using the receiver, a timing indicator that identifies a time of an expiration of the configuration.
The apparatus of claim 22, further comprising a transmitter, and wherein the instructions to receive the configuration are further executable by the processor to cause the apparatus to:

determine that the configuration is expired based at least in part on the timing indicator; and

request, using the transmitter, an updated configuration in response to determining that the configuration is expired.
The apparatus of claim 22, wherein the instructions to receive the configuration are further executable by the processor to cause the apparatus to:

compare the received configuration to a previous configuration the first UE received prior to entering the inactive state or the idle state; and

determine whether the received configuration differs from the previous configuration, wherein the determining of the timing advance value for uplink communications with the base station based at least in part on the first UE performing the measurement procedure on the received reference signals is based at least in part on a determination that the received configuration differs from the previous configuration.
An apparatus for wireless communication at a first user equipment (UE) , comprising:

means for receiving a configuration that indicates resources for the first UE to use to perform, in an inactive state or an idle state of a wireless connection of the first UE and a base station, a measurement procedure on reference signals transmitted by one or more UEs;

means for receiving, in the inactive state or the idle state, the reference signals on the resources indicated by the configuration;

means for determining a timing advance value for uplink communications with the base station based at least in part on the first UE performing the measurement procedure on the received reference signals; and

means for communicating, in the inactive or idle state for the wireless connection with the base station, on a sidelink connection with a second UE according to the determined timing advance value for the uplink communications with the base station.
The apparatus of claim 25, further comprising:

means for performing the measurement procedure on the reference signals on the resources during an active state of the wireless connection of the first UE and the base station, wherein the received configuration further indicates for the first UE to continue to perform the measurement procedure on the reference signals on the resources indicated by the configuration for a time duration.
The apparatus of claim 25, wherein the means for receiving the configuration comprise:

means for receiving a broadcast of system information that identifies the configuration.
The apparatus of claim 25, wherein the means for receiving the configuration comprise:

means for receiving the configuration from the second UE over the sidelink connection or from a third UE over a different sidelink connection.
A non-transitory computer-readable medium storing code for wireless communication at a first user equipment (UE) , the code comprising instructions executable by a processor to:

receive a configuration that indicates resources for the first UE to use to perform, in an inactive state or an idle state of a wireless connection of the first UE and a base station, a measurement procedure on reference signals transmitted by one or more UEs;

receive, in the inactive state or the idle state, the reference signals on the resources indicated by the configuration;

determine a timing advance value for uplink communications with the base station based at least in part on the first UE performing the measurement procedure on the received reference signals; and

communicate, in the inactive or idle state for the wireless connection with the base station, on a sidelink connection with a second UE according to the determined timing advance value for the uplink communications with the base station.
The non-transitory computer-readable medium of claim 29, wherein the instructions are further executable by the processor to:

perform the measurement procedure on the reference signals on the resources during an active state of the wireless connection of the first UE and the base station, wherein the received configuration further indicates for the first UE to continue to perform the measurement procedure on the reference signals on the resources indicated by the configuration for a time duration.