WO2022016480A1

WO2022016480A1 - Sidelink communication timing configuration and control for simultaneous activities at user equipment

Info

Publication number: WO2022016480A1
Application number: PCT/CN2020/103986
Authority: WO
Inventors: Yuwei REN; Huilin Xu
Original assignee: Qualcomm Incorporated
Priority date: 2020-07-24
Filing date: 2020-07-24
Publication date: 2022-01-27

Abstract

Aspects of the present disclosure provide various apparatus and methods for sidelink communication. In some aspects, a UE can use a common timing to perform a first sidelink communication and simultaneously cross link interference (CLI) measurement, a second sidelink communication, or network communication including uplink and downlink communications.

Description

SIDELINK COMMUNICATION TIMING CONFIGURATION AND CONTROL FOR SIMULTANEOUS ACTIVITIES AT USER EQUIPMENT

TECHNICAL FIELD

The technology discussed below relates generally to wireless communication systems, and more particularly, to sidelink communication and timing control for simultaneous sidelink communication and network communication.

INTRODUCTION

Wireless communication devices, sometimes referred to as user equipment (UE) , may communicate with a base station or may communicate directly with another UE. When a UE communicates directly with another UE, the communication can be referred to as device-to-device (D2D) or sidelink communication. In sidelink communication, voice and data traffic from one UE may be transmitted to one or more other UEs without the communication signals passing through a base station of a telecommunication network. In a 5G New Radio (NR) network, the connection between a UE and a base station may be called a Uu link or interface, and the sidelink connection between two UEs may be called a PC5 link. In some scenarios, the UE may have both the Uu link and PC5 link communication active simultaneously. As the demand for mobile broadband access continues to increase, research and development continue to advance sidelink communication not only to meet the growing demand for mobile broadband access, but to advance and enhance the user experience with mobile communications.

BRIEF SUMMARY OF SOME EXAMPLES

The following presents a summary of one or more aspects of the present disclosure, in order to provide a basic understanding of such aspects. This summary is not an extensive overview of all contemplated features of the disclosure, and is intended neither to identify key or critical elements of all aspects of the disclosure nor to delineate the scope of any or all aspects of the disclosure. Its sole purpose is to present some concepts of one or more aspects of the disclosure in a form as a prelude to the more detailed description that is presented later.

One aspect of the disclosure provides a method of wireless communication at a first scheduling entity. The first scheduling entity determines a sidelink communication mode for sidelink communication between a first user equipment (UE) and a second UE. The first scheduling entity schedules a transmission of a first sidelink signal from the first UE to the second UE according to the sidelink communication mode. The sidelink communication mode provides a common timing for receiving the first sidelink signal at the second UE and at least one of: determining a cross link interference (CLI) from a third UE; receiving a downlink transmission from the first scheduling entity; or receiving the first sidelink signal and receiving a second sidelink signal from a fourth UE that is associated with a second scheduling entity.

One aspect of the disclosure provides a method of wireless communication at a first UE. The first UE receives, from a first scheduling entity, sidelink configuration information of a sidelink connection between the first UE and a second UE. The first UE further selects a sidelink transmission mode based on the sidelink configuration information. The first UE further receives, from the second UE, a first sidelink signal based on the selected sidelink transmission mode. The first UE uses a common timing for receiving the first sidelink signal and at least one of: determining a cross link interference (CLI) from a third UE based on the common timing; receiving a downlink transmission from the first scheduling entity based on the common timing; or receiving a second sidelink signal from a fourth UE that is associated with a second scheduling entity based on the common timing.

One aspect of the disclosure provides a first scheduling entity for wireless communication. The first scheduling entity includes a communication interface configured for wireless communication, a memory, and a processor operatively coupled with the communication interface and the memory. The processor and the memory are configured to determine a sidelink communication mode for sidelink communication between a first user equipment (UE) and a second UE; and schedule a transmission of a first sidelink signal from the first UE to the second UE according to the sidelink communication mode. The sidelink communication mode provides a common timing for receiving the first sidelink signal at the second UE and at least one of: determining a cross link interference (CLI) from a third UE; receiving a downlink transmission from the first scheduling entity; or receiving a second sidelink signal from a fourth UE that is associated with a second scheduling entity.

One aspect of the disclosure provides a first UE for wireless communication. The first UE includes a communication interface configured for wireless communication, a memory, and a processor operatively coupled with the communication interface and the memory. The processor and the memory are configured to receive, from a first scheduling entity, sidelink configuration information of a sidelink connection between the first UE and a second UE. The processor and the memory are further configured to select a sidelink transmission mode based on the sidelink configuration information. The processor and the memory are further configured to receive, from the second UE, a first sidelink signal based on the selected sidelink transmission mode such that the first UE uses a common timing for receiving the first sidelink signal. In one aspect, the first UE uses the common timing for receiving the first sidelink signal and determining CLI from a third UE. In one aspect, the first UE uses the common timing for receiving the first sidelink signal and receiving a downlink transmission from the first scheduling entity. In one aspect, the first UE uses the common timing for receiving the first sidelink signal and receiving a second sidelink signal from a fourth UE that is associated with a second scheduling entity.

One aspect of the disclosure provides a first scheduling entity for wireless communication. The first scheduling entity includes means for determining a sidelink communication mode for sidelink communication between a first user equipment (UE) and a second UE; and means for scheduling a transmission of a sidelink signal from the first UE to the second UE according to the sidelink communication mode. The sidelink communication mode provides a common timing for receiving the first sidelink signal at the second UE and at least one of: determining a cross link interference (CLI) from a third UE; receiving a downlink transmission from the first scheduling entity; or receiving a second sidelink signal from a fourth UE that is associated with a second scheduling entity.

One aspect of the disclosure provides a first UE for wireless communication. The first UE includes means for receiving, from a first scheduling entity, sidelink configuration information of a sidelink connection between the first UE and a second UE. The first UE further includes means for selecting a sidelink transmission mode based on the sidelink configuration information. The first UE further includes means for receiving, from the second UE, a first sidelink signal based on the selected sidelink transmission mode such that the first UE uses a common timing for receiving the first sidelink signal. In one aspect, the first UE uses a common timing for receiving the first sidelink signal and determining CLI from a third UE. In one aspect, the first UE uses a common timing for receiving the first sidelink signal and receiving a downlink transmission from the first scheduling entity based on the common timing. In one aspect, the first UE uses a common timing for receiving the first sidelink signal and receiving a second sidelink signal from a fourth UE that is associated with a second scheduling entity.

One aspect of the disclosure provides a computer-readable storage medium stored with executable code for wireless communication. The executable code causes a first scheduling entity to determine a sidelink communication mode for sidelink communication between a first user equipment (UE) and a second UE; and schedule a transmission of a sidelink signal from the first UE to the second UE according to the sidelink communication mode. The sidelink communication mode provides a common timing for receiving the first sidelink signal at the second UE and at least one of: determining a cross link interference (CLI) from a third UE; receiving a downlink transmission from the first scheduling entity; or receiving a second sidelink signal from a fourth UE that is associated with a second scheduling entity.

One aspect of the disclosure provides a computer-readable storage medium stored with executable code for wireless communication. The executable code causes a first UE to receive, from a first scheduling entity, sidelink configuration information of a sidelink connection between the first UE and a second UE. The executable code further causes the first UE to select a sidelink transmission mode based on the sidelink configuration information. The executable code further causes the first UE to receive, from the second UE, a first sidelink signal based on the selected sidelink transmission mode such that the first UE uses a common timing for receiving the first sidelink signal. In one aspect, the first UE uses the common timing for receiving the first sidelink signal and determining CLI from a third UE. In one aspect, the first UE uses the common timing for receiving the first sidelink signal and receiving a downlink transmission from the first scheduling entity. In one aspect, the first UE uses the common timing for receiving the first sidelink signal and receiving a second sidelink signal from a fourth UE that is associated with a second scheduling entity.

These and other aspects of the invention will become more fully understood upon a review of the detailed description, which follows. Other aspects, features, and embodiments will become apparent to those of ordinary skill in the art, upon reviewing the following description of specific, exemplary embodiments in conjunction with the accompanying figures. While features may be discussed relative to certain embodiments and figures below, all embodiments can include one or more of the advantageous features discussed herein. In other words, while one or more embodiments may be discussed as having certain advantageous features, one or more of such features may also be used in accordance with the various embodiments discussed herein. In similar fashion, while exemplary embodiments may be discussed below as device, system, or method embodiments it should be understood that such exemplary embodiments can be implemented in various devices, systems, and methods.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic illustration of a wireless communication system according to some aspects.

FIG. 2 is an illustration of an example of a radio access network according to some aspects.

FIG. 3 is a schematic illustration of an organization of wireless resources in an air interface utilizing orthogonal frequency divisional multiplexing (OFDM) according to some aspects.

FIG. 4 is a diagram illustrating a first mode of sidelink timing configuration according to some aspects.

FIG. 5 is a diagram illustrating a second mode of sidelink timing configuration according to some aspects.

FIG. 6 is a diagram illustrating a third mode of sidelink timing configuration according to some aspects.

FIG. 7 is a schematic illustration of an uplink transmission and a sidelink transmission in the same symbol according to some aspects.

FIG. 8 is a schematic illustration of exemplary sidelink transmission modes according to some aspects.

FIG. 9 is a block diagram illustrating an example of a hardware implementation for a scheduling entity according to some aspects of the disclosure.

FIG. 10 is a flow chart illustrating an exemplary process for configuring sidelink communication according to some aspects.

FIG. 11 is a block diagram illustrating an example of a hardware implementation for a scheduled entity according to some aspects of the disclosure.

FIG. 12 is a flow chart illustrating an exemplary process for sidelink communication at a sidelink transmitter according to some aspects.

FIG. 13 is a flow chart illustrating an exemplary process for sidelink communication at a sidelink receiver according to some aspects.

DETAILED DESCRIPTION

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

While aspects and embodiments are described in this application by illustration to some examples, those skilled in the art will understand that additional implementations and use cases may come about in many different arrangements and scenarios. Innovations described herein may be implemented across many differing platform types, devices, systems, shapes, sizes, packaging arrangements. For example, embodiments and/or uses may come about via integrated chip embodiments and other non-module-component based devices (e.g., end-user devices, vehicles, communication devices, computing devices, industrial equipment, retail/purchasing devices, medical devices, AI-enabled devices, etc. ) . While some examples may or may not be specifically directed to use cases or applications, a wide assortment of applicability of described innovations may occur. Implementations may range a spectrum from chip-level or modular components to non-modular, non-chip-level implementations and further to aggregate, distributed, or OEM devices or systems incorporating one or more aspects of the described innovations. In some practical settings, devices incorporating described aspects and features may also necessarily include additional components and features for implementation and practice of claimed and described embodiments. For example, transmission and reception of wireless signals necessarily includes a number of components for analog and digital purposes (e.g., hardware components including antenna, RF-chains, power amplifiers, modulators, buffer, processor (s) , interleaver, adders/summers, etc. ) . It is intended that innovations described herein may be practiced in a wide variety of devices, chip-level components, systems, distributed arrangements, end-user devices, etc. of varying sizes, shapes and constitution.

Aspects of the present disclosure provide various apparatus and methods for sidelink communication. Sidelink communication is an example of device-to-device (D2D) wireless communication. In a wireless network, sidelink communication and network communication between a base station and a user equipment (UE) can occur simultaneously. In some aspects, a UE can perform sidelink communication and simultaneously cross link interference (CLI) measurement or network communication.

The various concepts presented throughout this disclosure may be implemented across a broad variety of telecommunication systems, network architectures, and communication standards. Referring now to FIG. 1, as an illustrative example without limitation, various aspects of the present disclosure are illustrated with reference to a wireless communication system 100. The wireless communication system 100 includes three interacting domains: a core network 102, a radio access network (RAN) 104, and a user equipment (UE) 106. By virtue of the wireless communication system 100, the UE 106 may be enabled to carry out data communication with an external data network 110, such as (but not limited to) the Internet.

The RAN 104 may implement any suitable wireless communication technology or technologies to provide radio access to the UE 106. As one example, the RAN 104 may operate according to 3 ^rd Generation Partnership Project (3GPP) New Radio (NR) specifications, often referred to as 5G. As another example, the RAN 104 may operate under a hybrid of 5G NR and Evolved Universal Terrestrial Radio Access Network (eUTRAN) standards, often referred to as LTE. The 3GPP refers to this hybrid RAN as a next-generation RAN, or NG-RAN. Of course, many other examples may be utilized within the scope of the present disclosure.

As illustrated, the RAN 104 includes a plurality of base stations 108. Broadly, a base station is a network element in a radio access network responsible for radio transmission and reception in one or more cells to or from a UE. In different technologies, standards, or contexts, a base station may variously be referred to by those skilled in the art as a base transceiver station (BTS) , a radio base station, a radio transceiver, a transceiver function, a basic service set (BSS) , an extended service set (ESS) , an access point (AP) , a Node B (NB) , an eNode B (eNB) , a gNode B (gNB) , or some other suitable terminology.

The radio access network 104 is further illustrated supporting wireless communication for multiple mobile apparatuses. A mobile apparatus may be referred to as user equipment (UE) in 3GPP standards, but may also be referred to by those skilled in the art as a mobile station (MS) , a subscriber station, a mobile unit, a subscriber unit, a wireless unit, a remote unit, a mobile device, a wireless device, a wireless communications device, a remote device, a mobile subscriber station, an access terminal (AT) , a mobile terminal, a wireless terminal, a remote terminal, a handset, a terminal, a user agent, a mobile client, a client, or some other suitable terminology. A UE may be an apparatus (e.g., a mobile apparatus) that provides a user with access to network services.

Within the present document, a “mobile” apparatus need not necessarily have a capability to move, and may be stationary. The term mobile apparatus or mobile device broadly refers to a diverse array of devices and technologies. UEs may include a number of hardware structural components sized, shaped, and arranged to help in communication; such components can include antennas, antenna arrays, RF chains, amplifiers, one or more processors, etc. electrically coupled to each other. For example, some non-limiting examples of a mobile apparatus include a mobile, a cellular (cell) phone, a smart phone, a session initiation protocol (SIP) phone, a laptop, a personal computer (PC) , a notebook, a netbook, a smartbook, a tablet, a personal digital assistant (PDA) , and a broad array of embedded systems, e.g., corresponding to an “Internet of things” (IoT) . A mobile apparatus may additionally be an automotive or other transportation vehicle, a remote sensor or actuator, a robot or robotics device, a satellite radio, a global positioning system (GPS) device, an object tracking device, a drone, a multi-copter, a quad-copter, a remote control device, a consumer and/or wearable device, such as eyewear, a wearable camera, a virtual reality device, a smart watch, a health or fitness tracker, a digital audio player (e.g., MP3 player) , a camera, a game console, etc. A mobile apparatus may additionally be a digital home or smart home device such as a home audio, video, and/or multimedia device, an appliance, a vending machine, intelligent lighting, a home security system, a smart meter, etc. A mobile apparatus may additionally be a smart energy device, a security device, a solar panel or solar array, a municipal infrastructure device controlling electric power (e.g., a smart grid) , lighting, water, etc.; an industrial automation and enterprise device; a logistics controller; agricultural equipment, etc. Still further, a mobile apparatus may provide for connected medicine or telemedicine support, e.g., health care at a distance. Telehealth devices may include telehealth monitoring devices and telehealth administration devices, whose communication may be given preferential treatment or prioritized access over other types of information, e.g., in terms of prioritized access for transport of critical service data, and/or relevant QoS for transport of critical service data.

Wireless communication between a RAN 104 and a UE 106 may be described as utilizing an air interface. Transmissions over the air interface from a base station (e.g., base station 108) to one or more UEs (e.g., UE 106) may be referred to as downlink (DL) transmission. In accordance with certain aspects of the present disclosure, the term downlink may refer to a point-to-multipoint transmission originating at a scheduling entity (described further below; e.g., base station 108) . Another way to describe this scheme may be to use the term broadcast channel multiplexing. Transmissions from a UE (e.g., UE 106) to a base station (e.g., base station 108) may be referred to as uplink (UL) transmissions. In accordance with further aspects of the present disclosure, the term uplink may refer to a point-to-point transmission originating at a scheduled entity (described further below; e.g., UE 106) .

In some examples, access to the air interface may be scheduled, wherein a scheduling entity (e.g., a base station 108) allocates resources for communication among some or all devices and equipment within its service area or cell. Within the present disclosure, as discussed further below, the scheduling entity may be responsible for scheduling, assigning, reconfiguring, and releasing resources for one or more scheduled entities. That is, for scheduled communication, UEs 106, which may be scheduled entities, may utilize resources allocated by the scheduling entity 108.

Base stations 108 are not the only entities that may function as scheduling entities. That is, in some examples, a UE may function as a scheduling entity, scheduling resources for one or more scheduled entities (e.g., one or more other UEs) .

As illustrated in FIG. 1, a scheduling entity 108 may broadcast downlink traffic 112 to one or more scheduled entities 106. Broadly, the scheduling entity 108 is a node or device responsible for scheduling traffic in a wireless communication network, including the downlink traffic 112 and, in some examples, uplink traffic 116 from one or more scheduled entities 106 to the scheduling entity 108. On the other hand, the scheduled entity 106 is a node or device that receives downlink control information 114, including but not limited to scheduling information (e.g., a grant) , synchronization or timing information, or other control information from another entity in the wireless communication network such as the scheduling entity 108. The scheduled entities 106 may communicate with each other directly using sidelink or D2D communication. In some examples, the scheduling entity 108 may schedule the resources (e.g., time and frequency resources) used for sidelink communication between two scheduled entities 106.

In general, base stations 108 may include a backhaul interface for communication with a backhaul portion 120 of the wireless communication system. The backhaul 120 may provide a link between a base station 108 and the core network 102. Further, in some examples, a backhaul network may provide interconnection between the respective base stations 108. Various types of backhaul interfaces may be employed, such as a direct physical connection, a virtual network, or the like using any suitable transport network.

The core network 102 may be a part of the wireless communication system 100, and may be independent of the radio access technology used in the RAN 104. In some examples, the core network 102 may be configured according to 5G standards (e.g., 5GC) . In other examples, the core network 102 may be configured according to a 4G evolved packet core (EPC) , or any other suitable standard or configuration.

FIG. 2 is an illustration of an example of a radio access network (RAN) 200 according to some aspects. In some examples, the RAN 200 may be the same as the RAN 104 described above and illustrated in FIG. 1. The geographic area covered by the RAN 200 may be divided into cellular regions (cells) that can be uniquely identified by a user equipment (UE) based on an identification broadcasted from one access point or base station. FIG. 2 illustrates

macrocells

202, 204, and 206, and a small cell 208, each of which may include one or more sectors (not shown) . A sector is a sub-area of a cell. All sectors within one cell are served by the same base station. A radio link within a sector can be identified by a single logical identification belonging to that sector. In a cell that is divided into sectors, the multiple sectors within a cell can be formed by groups of antennas with each antenna responsible for communication with UEs in a portion of the cell.

In FIG. 2, two base stations 210 and 212 are shown in

cells

202 and 204; and a third base station 214 is shown controlling a remote radio head (RRH) 216 in cell 206. That is, a base station can have an integrated antenna or can be connected to an antenna or RRH by feeder cables. In the illustrated example, the

cells

202, 204, and 126 may be referred to as macrocells, as the

base stations

210, 212, and 214 support cells having a large size. Further, a base station 218 is shown in the small cell 208 (e.g., a microcell, picocell, femtocell, home base station, home Node B, home eNode B, etc. ) which may overlap with one or more macrocells. In this example, the cell 208 may be referred to as a small cell, as the base station 218 supports a cell having a relatively small size. Cell sizing can be done according to system design as well as component constraints.

It is to be understood that the radio access network 200 may include any number of wireless base stations and cells. Further, a relay node may be deployed to extend the size or coverage area of a given cell. The

base stations

210, 212, 214, 218 provide wireless access points to a core network for any number of mobile apparatuses. In some examples, the

base stations

210, 212, 214, and/or 218 may be the same as the base station/scheduling entity 108 described above and illustrated in FIG. 1.

FIG. 2 further includes a quadcopter or drone 220, which may be configured to function as a base station. That is, in some examples, a cell may not necessarily be stationary, and the geographic area of the cell may move according to the location of a mobile base station such as the quadcopter 220.

Within the RAN 200, the cells may include UEs that may be in communication with one or more sectors of each cell. Further, each

base station

210, 212, 214, 218, and 220 may be configured to provide an access point to a core network 102 (see FIG. 1) for all the UEs in the respective cells. For example, UEs 222 and 224 may be in communication with base station 210;

UEs

226 and 228 may be in communication with base station 212;

UEs

230 and 232 may be in communication with base station 214 by way of RRH 216; UE 234 may be in communication with base station 218; and UE 236 may be in communication with mobile base station 220. In some examples, the

UEs

222, 224, 226, 228, 230, 232, 234, 236, 238, 240, and/or 242 may be the same as the UE/scheduled entity 106 described above and illustrated in FIG. 1. In some aspects, the communication link (e.g., UL connection or DL connection) between a UE and a base station may be referred to as a Uu link in this disclosure.

In some examples, a mobile network node (e.g., quadcopter 220) may be configured to function as a UE. For example, the quadcopter 220 may operate within cell 202 by communicating with base station 210.

In a further aspect of the RAN 200, sidelink or D2D signals may be used between UEs with or without necessarily relying on scheduling or control information from a base station. For example, two or more UEs (e.g., UEs 226 and 228) may communicate with each other using peer-to-peer (P2P) or sidelink signals 227 without relaying that communication through a base station (e.g., base station 212) . In a further example, UE 238 is illustrated communicating with

UEs

240 and 242. Here, the UE 238 may function as a scheduling entity or a primary sidelink device, and

UEs

240 and 242 may function as a scheduled entity or a non-primary (e.g., secondary) sidelink device. In still another example, a UE may function as a scheduling entity in a device-to-device (D2D) , peer-to-peer (P2P) , or vehicle-to-vehicle (V2V) network, and/or in a mesh network. In a mesh network example,

UEs

240 and 242 may optionally communicate directly with one another in addition to communicating with the scheduling entity 238. Thus, in a wireless communication system with scheduled access to time–frequency resources and having a cellular configuration, a P2P configuration, or a mesh configuration, a scheduling entity and one or more scheduled entities may communicate utilizing the scheduled resources. In some aspects, a communication link (e.g., sidelink) between two UEs may be referred to as a PC5 link in this disclosure.

In the radio access network 200, the ability for a UE to communicate while moving, independent of its location, is referred to as mobility. The various physical channels between the UE and the radio access network are generally set up, maintained, and released under the control of an access and mobility management function (AMF, not illustrated, part of the core network 102 in FIG. 1) , which may include a security context management function (SCMF) that manages the security context for both the control plane and the user plane functionality, and a security anchor function (SEAF) that performs authentication.

In various aspects of the disclosure, a radio access network 200 may utilize DL-based mobility or UL-based mobility to enable mobility and handovers (i.e., the transfer of a UE’s connection from one radio channel to another) . In a network configured for DL-based mobility, during a call with a scheduling entity, or at any other time, a UE may monitor various parameters of the signal from its serving cell as well as various parameters of neighboring cells. Depending on the quality of these parameters, the UE may maintain communication with one or more of the neighboring cells. During this time, if the UE moves from one cell to another, or if signal quality from a neighboring cell exceeds that from the serving cell for a given amount of time, the UE may undertake a handoff or handover from the serving cell to the neighboring (target) cell. For example, UE 224 (illustrated as a vehicle, although any suitable form of UE may be used) may move from the geographic area corresponding to its serving cell 202 to the geographic area corresponding to a neighbor cell 206. When the signal strength or quality from the neighbor cell 206 exceeds that of its serving cell 202 for a given amount of time, the UE 224 may transmit a reporting message to its serving base station 210 indicating this condition. In response, the UE 224 may receive a handover command, and the UE may undergo a handover to the cell 206.

In a network configured for UL-based mobility, UL reference signals from each UE may be utilized by the network to select a serving cell for each UE. In some examples, the

base stations

210, 212, and 214/216 may broadcast unified synchronization signals (e.g., unified Primary Synchronization Signals (PSSs) , unified Secondary Synchronization Signals (SSSs) and unified Physical Broadcast Channels (PBCH) ) . The

UEs

222, 224, 226, 228, 230, and 232 may receive the unified synchronization signals, derive the carrier frequency and slot timing from the synchronization signals, and in response to deriving timing, transmit an uplink pilot or reference signal. The uplink pilot signal transmitted by a UE (e.g., UE 224) may be concurrently received by two or more cells (e.g., base stations 210 and 214/216) within the radio access network 200. Each of the cells may measure a strength of the pilot signal, and the radio access network (e.g., one or more of the base stations 210 and 214/216 and/or a central node within the core network) may determine a serving cell for the UE 224. As the UE 224 moves through the radio access network 200, the network may continue to monitor the uplink pilot signal transmitted by the UE 224. When the signal strength or quality of the pilot signal measured by a neighboring cell exceeds that of the signal strength or quality measured by the serving cell, the network 200 may handover the UE 224 from the serving cell to the neighboring cell, with or without informing the UE 224.

Although the synchronization signal transmitted by the

base stations

210, 212, and 214/216 may be unified, the synchronization signal may not identify a particular cell, but rather may identify a zone of multiple cells operating on the same frequency and/or with the same timing. The use of zones in 5G networks or other next generation communication networks enables the uplink-based mobility framework and improves the efficiency of both the UE and the network, since the number of mobility messages that need to be exchanged between the UE and the network may be reduced.

The air interface in the radio access network 200 may utilize one or more duplexing algorithms. Duplex refers to a point-to-point communication link where both endpoints can communicate with one another in both directions. Full duplex means both endpoints can simultaneously communicate with one another. Half duplex means only one endpoint can send information to the other at a time. In a wireless link, a full duplex channel generally relies on physical isolation of a transmitter and receiver, and suitable interference cancellation technologies. Full duplex emulation is frequently implemented for wireless links by utilizing frequency division duplex (FDD) or time division duplex (TDD) . In FDD, transmissions in different directions operate at different carrier frequencies. In TDD, transmissions in different directions on a given channel are separated from one another using time division multiplexing. That is, at some times the channel is dedicated for transmissions in one direction, while at other times the channel is dedicated for transmissions in the other direction, where the direction may change very rapidly, e.g., several times per slot.

The air interface in the radio access network 200 may utilize one or more multiplexing and multiple access algorithms to enable simultaneous communication of the various devices. For example, 5G NR specifications provide multiple access for UL transmissions from UEs 222 and 224 to base station 210, and for multiplexing for DL transmissions from base station 210 to one or more UEs 222 and 224, utilizing orthogonal frequency division multiplexing (OFDM) with a cyclic prefix (CP) . In addition, for UL transmissions, 5G NR specifications provide support for discrete Fourier transform-spread-OFDM (DFT-s-OFDM) with a CP (also referred to as single-carrier FDMA (SC-FDMA) ) . However, within the scope of the present disclosure, multiplexing and multiple access are not limited to the above schemes, and may be provided utilizing time division multiple access (TDMA) , code division multiple access (CDMA) , frequency division multiple access (FDMA) , sparse code multiple access (SCMA) , resource spread multiple access (RSMA) , or other suitable multiple access schemes. Further, multiplexing DL transmissions from the base station 210 to UEs 222 and 224 may be provided utilizing time division multiplexing (TDM) , code division multiplexing (CDM) , frequency division multiplexing (FDM) , orthogonal frequency division multiplexing (OFDM) , sparse code multiplexing (SCM) , or other suitable multiplexing schemes.

Various aspects of the present disclosure will be described with reference to an OFDM waveform, schematically illustrated in FIG. 3. It should be understood by those of ordinary skill in the art that the various aspects of the present disclosure may be applied to a DFT-s-OFDMA waveform in substantially the same way as described herein below. That is, while some examples of the present disclosure may focus on an OFDM link for clarity, it should be understood that the same principles may be applied as well to DFT-s-OFDMA waveforms.

Within the present disclosure, a frame refers to a duration of 10 ms for wireless transmissions, with each frame consisting of 10 subframes of 1 ms each. On a given carrier, there may be one set of frames in the UL, and another set of frames in the DL. Referring now to FIG. 3, an expanded view of an exemplary DL subframe 302 is illustrated, showing an OFDM resource grid 304. However, as those skilled in the art will readily appreciate, the PHY transmission structure for any particular application may vary from the example described here, depending on any number of factors. Here, time is in the horizontal direction with units of OFDM symbols; and frequency is in the vertical direction with units of subcarriers or tones.

The resource grid 304 may be used to schematically represent time–frequency resources for a given antenna port. That is, in a MIMO implementation with multiple antenna ports available, a corresponding multiple number of resource grids 304 may be available for communication. The resource grid 304 is divided into multiple resource elements (REs) 306. An RE, which is 1 subcarrier × 1 symbol, is the smallest discrete part of the time–frequency grid, and contains a single complex value representing data from a physical channel or signal. Depending on the modulation utilized in a particular implementation, each RE may represent one or more bits of information. In some examples, a block of REs may be referred to as a physical resource block (PRB) or more simply a resource block (RB) 308, which contains any suitable number of consecutive subcarriers in the frequency domain. In one example, an RB may include 12 subcarriers, a number independent of the numerology used. In some examples, depending on the numerology, an RB may include any suitable number of consecutive OFDM symbols in the time domain. Within the present disclosure, it is assumed that a single RB such as the RB 308 entirely corresponds to a single direction of communication (either transmission or reception for a given device) .

A UE generally utilizes only a subset of the resource grid 304. An RB may be the smallest unit of resources that can be allocated to a UE. Thus, the more RBs scheduled for a UE, and the higher the modulation scheme chosen for the air interface, the higher the data rate for the UE.

In this illustration, the RB 308 is shown as occupying less than the entire bandwidth of the subframe 302, with some subcarriers illustrated above and below the RB 308. In a given implementation, the subframe 302 may have a bandwidth corresponding to any number of one or more RBs 308. Further, in this illustration, the RB 308 is shown as occupying less than the entire duration of the subframe 302, although this is merely one possible example.

Each subframe 302 (e.g., a 1ms subframe) may consist of one or multiple adjacent slots. In the example shown in FIG. 3, one subframe 302 includes four slots 310, as an illustrative example. In some examples, a slot may be defined according to a specified number of OFDM symbols with a given cyclic prefix (CP) length. For example, a slot may include 7 or 14 OFDM symbols with a nominal CP. Additional examples may include mini-slots having a shorter duration (e.g., 1, 2, 4, or 7 OFDM symbols) . These mini-slots may in some cases be transmitted occupying resources scheduled for ongoing slot transmissions for the same or for different UEs.

An expanded view of one of the slots 310 illustrates the slot 310 including a control region 312 and a data region 314 in one example. In general, the control region 312 may carry control channels (e.g., PDCCH) , and the data region 314 may carry data channels (e.g., PDSCH or PUSCH) . Of course, a slot may contain all DL, all UL, or at least one DL portion and at least one UL portion. The simple structure illustrated in FIG. 3 is merely exemplary in nature, and different slot structures may be utilized, and may include one or more of each of the control region (s) and data region (s) .

In another example, the slot 310 may include a control region 322 and a data region 324 for sidelink communication. The control region 322 may include a physical sidelink control channel (PSCCH) including sidelink control information transmitted by a transmitting sidelink device to one or more receiving sidelink devices nearby the transmitting sidelink device. In some examples, the sidelink control information may include synchronization information to synchronize communication by a plurality of sidelink devices on the sidelink channel. In some examples, the sidelink control information may include resource reservation information for sidelink transmission. In some examples, the sidelink control information may include information that indicates the location or distance of the transmitting device. In addition, the sidelink control information may include decoding information for a physical sidelink shared channel (PSSCH) transmitted within the data region 324. The PSSCH may include sidelink data transmitted by the transmitting sidelink device over the sidelink channel to a receiving sidelink device.

Scheduling of UEs for downlink, uplink, or sidelink transmissions typically involves scheduling one or more resource elements 306 within one or more sub-bands. Thus, a UE or sidelink device generally utilizes only a subset of the resource grid 304. In some examples, an RB may be the smallest unit of resources that can be allocated to a UE. Thus, the more RBs scheduled for a UE, and the higher the modulation scheme chosen for the air interface, the higher the data rate for the UE.

Although not illustrated in FIG. 3, the various REs 306 within an RB 308 may be scheduled to carry one or more physical channels, including control channels, shared channels, data channels, etc. Other REs 306 within the RB 308 may also carry pilots or reference signals. These pilots or reference signals may provide for a receiving device to perform channel estimation of the corresponding channel, which may enable coherent demodulation/detection of the control and/or data channels within the RB 308.

In a DL transmission, the transmitting device (e.g., the scheduling entity 108) may allocate one or more REs 306 (e.g., within a control region 312) to carry DL control information 114 including one or more DL control channels that generally carry information originating from higher layers, such as a physical broadcast channel (PBCH) , a physical downlink control channel (PDCCH) , etc., to one or more scheduled entities 106. In addition, DL REs may be allocated to carry DL physical signals that generally do not carry information originating from higher layers. These DL physical signals may include a primary synchronization signal (PSS) ; a secondary synchronization signal (SSS) ; demodulation reference signals (DM-RS) ; phase-tracking reference signals (PT-RS) ; channel-state information reference signals (CSI-RS) ; etc.

The synchronization signals PSS and SSS (collectively referred to as SS) , and in some examples, the PBCH, may be transmitted in an SS block that includes 4 consecutive OFDM symbols, numbered via a time index in increasing order from 0 to 3. In the frequency domain, the SS block may extend over 240 contiguous subcarriers, with the subcarriers being numbered via a frequency index in increasing order from 0 to 239. Of course, the present disclosure is not limited to this specific SS block configuration. Other nonlimiting examples may utilize greater or fewer than two synchronization signals; may include one or more supplemental channels in addition to the PBCH; may omit a PBCH; and/or may utilize nonconsecutive symbols for an SS block, within the scope of the present disclosure.

The PDCCH may carry downlink control information (DCI) for one or more UEs in a cell. This can include, but is not limited to, power control commands, scheduling information, a grant, and/or an assignment of REs for DL and UL transmissions.

In an UL transmission, a transmitting device (e.g., a scheduled entity 106) may utilize one or more REs 306 to carry UL control information 118 (UCI) . The UCI can originate from higher layers via one or more UL control channels, such as a physical uplink control channel (PUCCH) , a physical random access channel (PRACH) , etc., to the scheduling entity 108. Further, UL REs may carry UL physical signals that generally do not carry information originating from higher layers, such as demodulation reference signals (DM-RS) , phase-tracking reference signals (PT-RS) , sounding reference signals (SRS) , etc. In some examples, the control information 118 may include a scheduling request (SR) , i.e., a request for the scheduling entity 108 to schedule uplink transmissions. Here, in response to the SR transmitted on the control channel 118, the scheduling entity 108 may transmit downlink control information 114 that may schedule resources for uplink packet transmissions.

UL control information may also include hybrid automatic repeat request (HARQ) feedback such as an acknowledgment (ACK) or negative acknowledgment (NACK) , channel state information (CSI) , or any other suitable UL control information. HARQ is a technique well-known to those of ordinary skill in the art, wherein the integrity of packet transmissions may be checked at the receiving side for accuracy, e.g., utilizing any suitable integrity checking mechanism, such as a checksum or a cyclic redundancy check (CRC) . If the integrity of the transmission confirmed, an ACK may be transmitted, whereas if not confirmed, a NACK may be transmitted. In response to a NACK, the transmitting device may send a HARQ retransmission, which may implement chase combining, incremental redundancy, etc.

In addition to control information, one or more REs 306 (e.g., within the data region 314) may be allocated for user data or traffic data. Such traffic may be carried on one or more traffic channels, such as, for a DL transmission, a physical downlink shared channel (PDSCH) ; or for a UL transmission, a physical uplink shared channel (PUSCH) .

In order for a UE to gain initial access to a cell, the RAN may provide system information (SI) characterizing the cell. This system information may be provided utilizing minimum system information (MSI) , and other system information (OSI) . The MSI may be periodically broadcast over the cell to provide the most basic information required for initial cell access, and for acquiring any OSI that may be broadcast periodically or sent on-demand. In some examples, the MSI may be provided over two different downlink channels. For example, the PBCH may carry a master information block (MIB) , and the PDSCH may carry a system information block type 1 (SIB1) . In the art, SIB1 may be referred to as the remaining minimum system information (RMSI) .

OSI may include any SI that is not broadcast in the MSI. In some examples, the PDSCH may carry a plurality of SIBs, not limited to SIB1, discussed above. Here, the OSI may be provided in these SIBs, e.g., SIB2 and above.

The channels or carriers described above and illustrated in FIGs. 1 and 3 are not necessarily all the channels or carriers that may be utilized between a scheduling entity 108 and scheduled entities 106, and those of ordinary skill in the art will recognize that other channels or carriers may be utilized in addition to those illustrated, such as other traffic, control, and feedback channels.

These physical channels described above are generally multiplexed and mapped to transport channels for handling at the medium access control (MAC) layer. Transport channels carry blocks of information called transport blocks (TB) . The transport block size (TBS) , which may correspond to a number of bits of information, may be a controlled parameter, based on the modulation and coding scheme (MCS) and the number of RBs in a given transmission.

In some aspects, a UE may have a network connection (e.g., Uu link) with a network and simultaneously a sidelink connection (e.g., PC5 link) with another UE. In an inter-frequency example, the Uu link and PC5 link may be on different frequency carriers. In an intra-frequency example, the Uu link and PC5 link may be on the same frequency carrier. In general, simultaneous activities on a network connection and a sidelink connection require timing synchronization between the connections. Otherwise, separate fast Fourier transform (FFT) processes and time tracking loops may be needed that can increase the complexity and/or power consumption of the UE.

Cross Link Interference

Simultaneous network communication (e.g., UL or DL communication) and sidelink communication can cause cross link interference (CLI) . In some aspects, a UE can determine or measure CLI for Uu link interference management. CLI may occur between UEs within the same cell or different cells. A scheduling entity can schedule a victim UE to perform CLI measurement at the configured CLI resource due to transmission from the aggressor UE. In one example, the aggressor UE transmits an uplink transmission to its serving scheduling entity, and the victim UE can be configured with corresponding CLI measurement resources that overlap in time with the aggressor UE’s transmission. The victim UE measures the CLI using the configured resources and reports the CLI measurement to the network or scheduling entity.

Aspects of the present disclosure provide various techniques for sidelink timing configurations or modes that can enable simultaneous processing of sidelink communication with CLI measurement, network communication, or other sidelink communication.

Sidelink Transmission Timing Based on UL Tx Timing (Mode 1)

FIG. 4 is a diagram illustrating a first mode of sidelink timing configuration according to some aspects of the disclosure. In this example, a first UE 402 has a network connection (link 1) with a scheduling entity 404 (e.g., gNB or base station) . In this mode, the first UE 402 can use its UL transmit (Tx) timing 406 to transmit a sidelink signal 407 (link 2) to a second UE 408. That is, the first UE 402 can transmit the UL signal and the sidelink signal at the same time. In this mode, the sidelink receiver UE 408 can use a common timing 409 to receive the sidelink signal 410 (link 2) from the first UE 402 and simultaneously measure CLI 412 (link 4) from a third UE 414. The first UE 402 and third UE 414 may be associated with the same scheduling entity 404.

In some aspects, the sidelink receiver UE 408 can use its own UL Tx timing as the common timing 409 if the second UE 408 has a network connection with the same scheduling entity 404 as the sidelink transmit UE 402. Using the common timing 409 for receiving the sidelink signal 410 and concurrently measuring CLI 412 allows the second UE 408 to use the same FFT processes and time tracking loops to receive the sidelink signal 410 from the first UE and measure CLI 412 from the third UE. In some aspects, the CLI may be caused by a transmission of another UE that is close to the receiver UE 408. In some aspects, the sidelink transmission and UL transmission may be intra-frequency or inter-frequency transmissions.

In more detail, the first UE 402 can use its UL Tx timing 406 of link 1 for transmitting the sidelink signal 407 (link 2) . In this case, the first UE 402 uses the same Tx timing 406 for both link 1 and link 2. The third UE 414 transmits its UL signal 416 to the scheduling entity 404 using a UL Tx timing that can be roughly aligned (e.g., within the same time symbol) with the first UE’s UL Tx timing 406. The UL transmission 416 of the third UE 414 can cause CLI (link 4) to the second UE 408. In one aspect, the second UE 408 can use a common timing 409 to receive the sidelink signal 410 from the first UE (link 2) and measure CLI 412 from the third UE (link 4) . In this example, the propagation delay between the UEs can be negligible because the UEs are sufficiently close to each other for enabling sidelink communication. In some aspects, the second UE 408 may use its own UL Tx timing to receive the sidelink signal (link 2) from the first UE 402 and measure the CLI from the third UE 414, if the second UE 408 has a communication link or connection with the same scheduling entity 404 as the first UE 402.

Sidelink Transmission Timing Based on DL Rx Timing (Mode 2)

FIG. 5 is a diagram illustrating a second mode of sidelink timing configuration according to some aspects of the disclosure. In this mode, a first UE 502 has a network connection (e.g., link 1) with a scheduling entity 504 (e.g., gNB or base station) . In some aspects, the first UE 502 can use its DL receive (Rx) timing 506 to transmit a sidelink signal 508 (link 2) to a second UE 509. In this case, the second UE 509 can use a common timing 510 to receive its DL transmission 512 from the scheduling entity 504 and simultaneously receive the sidelink signal 514 from the first UE 502 because both UEs are associated with the same scheduling entity and have similar timing DL timing.

In more detail, the first UE 502 and second UE 509 can access the same serving scheduling entity 504 via their respective Uu connections (link 1 and link 3) . Using the common timing 510, the second UE 509 can simultaneously maintain a sidelink connection (link 2) with the first UE 502 and a DL connection (link 3) with the scheduling entity 504. In this example, the first UE 502 and second UE 509 can have similar DL Rx timing (e.g., a difference within one symbol) because these UEs are sufficiently close to each other for enabling sidelink communication. Therefore, the first UE 502 can use its DL Rx timing 506 of link 1 as the sidelink transmit timing of link 2, and the second UE 509 can receive the sidelink signal of link 2 and simultaneously its DL signal (link 3) , using a common timing 510.

Sidelink Transmission Timing Based on DL Tx Timing (Mode 3)

FIG. 6 is a diagram illustrating a third mode of sidelink timing configuration according to some aspects of the disclosure. In this mode, a first UE 602 has a network connection (link 1) with a first scheduling entity 604 (e.g., gNB or base station) . The first UE 602 can use the DL Tx timing 606 of the first scheduling entity 604 to transmit a sidelink signal 610 (link 2) to a second UE 608. In some aspects, the first UE 602 can apply a constant timing offset between the DL Tx timing 606 and the sidelink Tx timing. In this mode, the second UE 608 can use a common timing 612 to receive the sidelink signal 615 from the first UE and another sidelink signal 616 from a third UE 614 (e.g., UE3) . This first UE and third UE are connected to

different scheduling entities

604 and 618.

In this mode, the first scheduling entity 604 and second scheduling entity 618 may be synchronized to have the same DL Tx timing (link 1 and link 3) . When the first UE 602 and third UE 614 are associated with

different scheduling entities

604 and 618, the first UE 602 and third UE 614 may have different propagation delay to their corresponding serving scheduling entities. In that case, the DL Rx timing may not be aligned between the first UE 602 and third UE 614. However, the DL Tx timing 606 at the scheduling entities are synchronized. The UEs can derive the DL Tx timing at their corresponding scheduling entities based on the DL Rx timing and their configured UL timing advance. In some aspects, the second UE 608 can use a common timing 612 to receive the sidelink signal 615 from the first UE 602 and the sidelink signal 616 from the third UE 614 using the same FFT processes and time tracking loops.

Sidelink Timing Mode Selection

In some aspects of the disclosure, the network can explicitly indicate the sidelink transmission timing mode to be used for sidelink communication between UEs. In one aspect, the scheduling entity can transmit sidelink configuration information using semi-static scheduling, for example, radio resource control (RRC) signaling or MAC CE (control element) signaling. In one aspect, the scheduling entity can transmit sidelink configuration information using dynamic scheduling, for example, downlink control information (DCI) in a PDCCH/PDSCH. The scheduling entity may transmit the sidelink timing configuration to the sidelink transmitter UE and/or sidelink receiver UE to configure sidelink communication between the UEs. The scheduling entity may schedule different sidelink timing modes in different scenarios, for example, sidelink communication between intra-cell or inter-cell UEs, sidelink communication using FR1 frequency, FR2 frequency, or a combination of FR1 and FR2, inter-frequency sidelink communication, intra-frequency sidelink communication, intra-band sidelink communication, and inter-band sidelink communication.

In some aspects, the network can implicitly indicate the sidelink transmission timing mode to be used for sidelink communication between UEs. With implicit signaling, a scheduling entity does not explicitly or expressly indicate the sidelink transmission timing mode to the UEs when certain scheduling conditions are met.

In one aspect, if the scheduling entity schedules a sidelink transmitter UE to perform a UL transmission 702 and a sidelink transmission 704 in the same symbol (see example in FIG. 7) , the sidelink transmitter UE can use its UL Tx timing for both the UL transmission 702 and sidelink transmission 704, without receiving explicit scheduling information from the scheduling entity to use the UL Tx timing for the sidelink transmission.

In one aspect, if the scheduling entity schedules a sidelink receiver UE to receive a sidelink signal 802 and measure CLI 804 in the same symbol (see mode 1 example of FIG. 8) , the sidelink receiver UE can determine that the sidelink transmitter UE uses its UL Tx timing for the sidelink transmission 802, without receiving explicit scheduling information from the scheduling entity to use a common timing (e.g., timing 409 in FIG. 4) for receiving the sidelink signal 802 and measuring CLI 804.

In one aspect, if the scheduling entity schedules a sidelink receiver UE to receive a DL transmission 806 and a sidelink signal 808 in the same symbol (see mode 2 example of FIG. 8) , the sidelink receiver UE can determine that the sidelink transmitter UE uses its DL Rx timing for the sidelink signal transmission, without receiving explicit scheduling information from the scheduling entity to use a common timing (e.g., timing 506 in FIG. 5) for receiving the DL transmission 806 and sidelink signal 808.

In one aspect, if the scheduling entity schedules a sidelink receiver UE to receive

sidelink signals

810 and 812 from different UEs in the same symbol (see mode 3 example of FIG. 8) , the sidelink receiver UE can determine that the sidelink transmitter UE uses the DL Tx timing of a scheduling entity for the sidelink signal transmission, without receiving explicit scheduling information from the scheduling entity to use a common timing (e.g., timing 612) for receiving the sidelink signals 810 and 812 from different UEs.

In some aspects, the simultaneous sidelink communication, CLI measurement, and/or network communication may use the same frequency band (intra-band) or different frequency bands (inter-bands) . In some aspects, simultaneous Tx or Rx may be on the same frequency carrier or different frequency carriers.

FIG. 9 is a block diagram illustrating an example of a hardware implementation for a scheduling entity 900 employing a processing system 914. For example, the scheduling entity 900 may be a base station illustrated in any one or more of FIGs. 1, 2, 4, 5, and/or 6.

The scheduling entity 900 may be implemented with a processing system 914 that includes one or more processors 904. Examples of processors 904 include microprocessors, microcontrollers, digital signal processors (DSPs) , field programmable gate arrays (FPGAs) , programmable logic devices (PLDs) , state machines, gated logic, discrete hardware circuits, and other suitable hardware configured to perform the various functionality described throughout this disclosure. In various examples, the scheduling entity 900 may be configured to perform any one or more of the functions described herein. That is, the processor 904, as utilized in a scheduling entity 900, may be used to implement any one or more of the processes and procedures described below and illustrated in FIG. 9.

In this example, the processing system 914 may be implemented with a bus architecture, represented generally by the bus 902. The bus 902 may include any number of interconnecting buses and bridges depending on the specific application of the processing system 914 and the overall design constraints. The bus 902 communicatively couples together various circuits including one or more processors (represented generally by the processor 904) , a memory 905, and computer-readable media (represented generally by the computer-readable medium 906) . The bus 902 may also link various other circuits such as timing sources, peripherals, voltage regulators, and power management circuits, which are well known in the art, and therefore, will not be described any further. A bus interface 908 provides an interface between the bus 902 and a transceiver 910. The transceiver 910 provides a communication interface or means for communicating with various other apparatus over a transmission medium. Depending upon the nature of the apparatus, a user interface 912 (e.g., keypad, display, speaker, microphone, joystick) may also be provided. Of course, such a user interface 912 is optional, and may be omitted in some examples, such as a base station.

In some aspects of the disclosure, the processor 904 may include circuitry configured for various functions, including, for example, sidelink communication and UL/DL communication. For example, the circuitry may be configured to implement one or more of the functions described in relation to FIGs. 4–8 and 10.

In one aspect, the processor 904 may include a scheduling circuit 940 and a communication circuit 942. The scheduling circuit 940 may be configured to perform various functions to schedule communication resources for use in sidelink, uplink (UL) , and/or downlink (DL) communication. For example, the scheduling circuit 940 may determine, allocate, assign, revoke, and reassign communication resources (e.g., time, frequency, and spatial resources) to one or more UEs associated with the scheduling entity. The communication circuit 942 may be configured to perform various functions to communicate with one or more UEs using DL and/or UL communication via the transceiver 910. The communication circuit 942 may also be configured to enable the scheduling entity 900 to coordinate with another scheduling entity to schedule sidelink communication between UEs that are associated with different scheduling entities.

The processor 904 is responsible for managing the bus 902 and general processing, including the execution of software stored on the computer-readable medium 906. The software, when executed by the processor 904, causes the processing system 914 to perform the various functions described below for any particular apparatus. The computer-readable medium 906 and the memory 905 may also be used for storing data that is manipulated by the processor 904 when executing software.

One or more processors 904 in the processing system may execute software. Software shall be construed broadly to mean instructions, instruction sets, code, code segments, program code, programs, subprograms, software modules, applications, software applications, software packages, routines, subroutines, objects, executables, threads of execution, procedures, functions, etc., whether referred to as software, firmware, middleware, microcode, hardware description language, or otherwise. The software may reside on a computer-readable medium 906. The computer-readable medium 906 may be a non-transitory computer-readable medium. A non-transitory computer-readable medium includes, by way of example, a magnetic storage device (e.g., hard disk, floppy disk, magnetic strip) , an optical disk (e.g., a compact disc (CD) or a digital versatile disc (DVD) ) , a smart card, a flash memory device (e.g., a card, a stick, or a key drive) , a random access memory (RAM) , a read only memory (ROM) , a programmable ROM (PROM) , an erasable PROM (EPROM) , an electrically erasable PROM (EEPROM) , a register, a removable disk, and any other suitable medium for storing software and/or instructions that may be accessed and read by a computer. The computer-readable medium 906 may reside in the processing system 914, external to the processing system 914, or distributed across multiple entities including the processing system 914. The computer-readable medium 906 may be embodied in a computer program product. By way of example, a computer program product may include a computer-readable medium in packaging materials. Those skilled in the art will recognize how best to implement the described functionality presented throughout this disclosure depending on the particular application and the overall design constraints imposed on the overall system.

In one or more examples, the computer-readable storage medium 906 may include software configured for various functions, including, for example, sidelink communication and UL/DL communication. For example, the software may be configured to implement one or more of the functions described in relation to FIGs. 4–8 and 10.

In one aspect, the software may include scheduling software 952 and communication software 954. The scheduling software 952 may cause the scheduling entity 900 to perform various functions to schedule communication resources for use in sidelink, UL, and/or DL communication. For example, the scheduling software 952 may determine, allocate, assign, revoke, and reassign communication resources (e.g., time, frequency, and spatial resources) to one or more UEs associated with the scheduling entity. The communication software 954 may cause the scheduling entity 900 to perform various functions to communicate with one or more UEs using DL and/or UL communication via the transceiver 910. The communication software 954 may also cause the scheduling entity 900 to coordinate with another scheduling entity to schedule sidelink communication between UEs associated with different scheduling entities.

FIG. 10 is a flow chart illustrating an exemplary process 1000 for configuring sidelink communication in accordance with some aspects of the present disclosure. As described below, some or all illustrated features may be omitted in a particular implementation within the scope of the present disclosure, and some illustrated features may not be required for implementation of all embodiments. In some examples, the process 1000 may be carried out by the scheduling entity 900 illustrated in FIG. 9. In some examples, the process 1000 may be carried out by any suitable apparatus or means for carrying out the functions or algorithm described below.

At block 1002, a first scheduling entity (e.g., gNB) determines a sidelink communication mode for sidelink communication between a first UE and a second UE. Then, the first scheduling entity can schedule a transmission of a first sidelink signal from the first UE to the second UE according to the sidelink communication mode. The sidelink communication mode provides a common timing for receiving the first sidelink signal at the second UE. The sidelink communication mode may be one of the sidelink communication modes described above in relation to FIGs. 4–8. In one aspect, the scheduling circuit 940 may provide the means for determining the communication mode and scheduling the sidelink communication. In one aspect, the communication circuit 942 may provide the means for communicating the scheduling information to the UEs.

In a first sidelink communication mode, the scheduling can cause the first UE to transmit a first sidelink signal to the second UE based on a timing of a communication link between the first UE and the first scheduling entity such that the second UE uses a common timing for receiving the first sidelink signal and determining a cross link interference (CLI) from a third UE. In this example, the first UE may use its UL Tx timing for transmitting the first sidelink signal.

In a second sidelink communication mode, the scheduling can cause the first UE to transmit a first sidelink signal to the second UE based on a timing of a communication link between the first UE and the first scheduling entity such that the second UE uses a common timing for receiving the first sidelink signal and receiving a downlink transmission from the first scheduling entity. In this example, the first UE may use its DL Rx timing for transmitting the first sidelink signal.

In a third sidelink communication mode, the scheduling can cause the first UE to transmit a first sidelink signal to the second UE based on a timing of a communication link between the first UE and the first scheduling entity such that the second UE uses a common timing for receiving the first sidelink signal and receiving a second sidelink signal from a fourth UE that is associated with a second scheduling entity. In this example, the first UE may use the DL Tx timing at the first scheduling entity for transmitting the first sidelink signal.

FIG. 11 is a diagram illustrating an example of a hardware implementation for an exemplary scheduled entity 1100 employing a processing system 1114. In accordance with various aspects of the disclosure, an element, or any portion of an element, or any combination of elements may be implemented with a processing system 1114 that includes one or more processors 1104. For example, the scheduled entity 1100 may be a user equipment (UE) as illustrated in any one or more of FIGs. 1, 2, 4, 5, and/or 6.

The processing system 1114 may be substantially the same as the processing system 1014 illustrated in FIG. 10, including a bus interface 1108, a bus 1102, memory 1105, a processor 1104, and a computer-readable medium 1106. Furthermore, the scheduled entity 1100 may include a user interface 1112 and a transceiver 1110 substantially similar to those described above in FIG. 10. That is, the processor 1104, as utilized in a scheduled entity 1100, may be used to implement any one or more of the processes described below and illustrated in FIG. 12.

In some aspects of the disclosure, the processor 1104 may include circuitry configured for various functions, including, for example, sidelink communication. For example, the circuitry may be configured to implement one or more of the functions described in relation to FIGs. 4–8 and 12.

In one aspect, the processor 1104 may include a sidelink communication circuit 1140 and a UL/DL communication circuit 1142. The sidelink communication circuit 1140 may be configured to perform various functions used for sidelink communication. For example, the sidelink communication circuit 1140 may transmit and/or receive a sidelink signal to/from another scheduled entity or UE via the transceiver 1110. The UL/DL communication circuit 1142 may be configured to perform various functions to communicate with a scheduling entity (e.g., gNB) using DL and/or UL communication via the transceiver 1110.

In one or more examples, the computer-readable storage medium 1106 may include software configured for various functions, including, for example, sidelink communication and UL/DL communication. For example, the software may be configured to implement one or more of the functions described in relation to FIGs. 4–8 and 12.

In one aspect, the computer-readable medium 1106 may include sidelink communication instructions 1152 and UL/DL communication instructions 1154. The sidelink communication instructions 1152 may be configured to perform various functions used for sidelink communication. For example, the sidelink communication instructions 1152 may cause the scheduled entity 1100 to transmit and/or receive a sidelink signal to/from another scheduled entity or UE via the transceiver 1110. The UL/DL communication instructions 1154 may cause the scheduled entity to perform various functions to communicate with a scheduling entity (e.g., gNB) using DL and/or UL communication via the transceiver 1110.

FIG. 12 is a flow chart illustrating an exemplary process 1200 for sidelink communication in accordance with some aspects of the present disclosure. As described below, some or all illustrated features may be omitted in a particular implementation within the scope of the present disclosure, and some illustrated features may not be required for implementation of all embodiments. In some examples, the process 1200 may be carried out by the scheduled entity 1100 illustrated in FIG. 11. In some examples, the process 1200 may be carried out by any suitable apparatus or means for carrying out the functions or algorithm described below.

At block 1202, a first UE (scheduled entity) establishes a communication link with a first scheduling entity (e.g., gNB) . In one aspect, the UL/DL communication circuit 1142 and/or transceiver 1110 may provide the means for establishing the communication link with the first scheduling entity. The communication link may be a Uu link between the first UE and the first scheduling entity. The first UE can transmit UL data to the scheduling entity and receive DL data from the scheduling entity using the Uu link.

At block 1204, the first UE selects a sidelink transmission mode. In one aspect, the sidelink communication circuit 1140 may provide the means for selecting the sidelink transmission mode. In a first sidelink transmission mode, the first UE may use a sidelink transmission timing based on a UL transmit timing of the first UE. In a second sidelink transmission mode, the first UE may use a sidelink transmission timing based on a DL receive timing at the first UE. In a third sidelink transmission mode, the first UE may use a sidelink transmission timing based on a DL transmit timing of the first scheduling entity. In some aspects, the first UE can receive an indication of the sidelink transmission mode from the scheduling entity. For example, the indication may be an RRC message, MAC CE, and/or DCI.

At block 1206, the first UE transmits a first sidelink signal to a second UE based on a timing of the communication link and the selected sidelink transmission mode. In one aspect, the sidelink communication circuit 1140 and/or the transceiver 1110 may provide the means for transmitting the first sidelink signal to the second UE. In the first sidelink transmission mode, when the sidelink transmission timing is based on the UL transmit timing of the first UE, the second UE can use a common timing to receive the first sidelink signal and determine a CLI from a third UE. In the second sidelink transmission mode, when the sidelink transmission timing is based on the DL receive timing at the first UE, the second UE can use a common timing to receive the first sidelink signal and receive a downlink transmission from the first scheduling entity. In the third sidelink transmission mode, when the sidelink transmission timing is based on the DL transmit timing at the first UE, the second UE can use a common timing to receive the first sidelink signal and receive a second sidelink signal from a fourth UE that is associated with a second scheduling entity.

FIG. 13 is a flow chart illustrating an exemplary process 1300 for sidelink communication in accordance with some aspects of the present disclosure. As described below, some or all illustrated features may be omitted in a particular implementation within the scope of the present disclosure, and some illustrated features may not be required for implementation of all embodiments. In some examples, the process 1300 may be carried out by the scheduled entity 1100 illustrated in FIG. 11. In some examples, the process 1300 may be carried out by any suitable apparatus or means for carrying out the functions or algorithm described below.

At block 1302, a first UE (scheduled entity) receives, from a first scheduling entity, sidelink configuration information of a sidelink connection between the first UE and a second UE. In one aspect, the UL/DL communication circuit 1142 and/or transceiver 1110 may provide the means for receiving the scheduling information. In one aspect, the first UE may receive the sidelink configuration information in an RRC message, MAC CE, and/or DCI.

At block 1304, the first UE selects a sidelink transmission mode based on the sidelink configuration information. In one aspect, the sidelink communication circuit 1140 may provide the means for selecting the sidelink transmission mode. In some aspects, the sidelink communication mode may be any of the sidelink communication modes described above in relation to FIGs. 4–8.

At block 1306, the first UE receives a first sidelink signal from the second UE based on the selected sidelink transmission mode. In one aspect, the sidelink communication circuit 1140 and/or transceiver 1110 may provide the means for receiving the first sidelink signal from the second UE. In one aspect, the first UE uses a common timing for receiving the first sidelink signal from the second UE and determining a CLI from a third UE. In this example, the common timing may be a UL transmit timing at the second UE. In one aspect, the first UE uses a common timing for receiving the first sidelink signal from the second UE and receiving a downlink transmission from the first scheduling entity. In this example, the common timing may be a DL receive timing at the second UE. In one aspect, the first UE uses a common timing for receiving the first sidelink signal from the second UE and receiving a second sidelink signal from a fourth UE that is associated with a second scheduling entity. In this example, the common timing may be a DL transmit timing at the first scheduling entity.

Several aspects of a wireless communication network have been presented with reference to an exemplary implementation. As those skilled in the art will readily appreciate, various aspects described throughout this disclosure may be extended to other telecommunication systems, network architectures and communication standards.

By way of example, various aspects may be implemented within other systems defined by 3GPP, such as Long-Term Evolution (LTE) , the Evolved Packet System (EPS) , the Universal Mobile Telecommunication System (UMTS) , and/or the Global System for Mobile (GSM) . Various aspects may also be extended to systems defined by the 3rd Generation Partnership Project 2 (3GPP2) , such as CDMA2000 and/or Evolution-Data Optimized (EV-DO) . Other examples may be implemented within systems employing IEEE 802.11 (Wi-Fi) , IEEE 802.16 (WiMAX) , IEEE 802.20, Ultra-Wideband (UWB) , Bluetooth, and/or other suitable systems. The actual telecommunication standard, network architecture, and/or communication standard employed will depend on the specific application and the overall design constraints imposed on the system.

Within the present disclosure, the word “exemplary” is used to mean “serving as an example, instance, or illustration. ” Any implementation or aspect described herein as “exemplary” is not necessarily to be construed as preferred or advantageous over other aspects of the disclosure. Likewise, the term “aspects” does not require that all aspects of the disclosure include the discussed feature, advantage or mode of operation. The term “coupled” is used herein to refer to the direct or indirect coupling between two objects. For example, if object A physically touches object B, and object B touches object C, then objects A and C may still be considered coupled to one another-even if they do not directly physically touch each other. For instance, a first object may be coupled to a second object even though the first object is never directly physically in contact with the second object. The terms “circuit” and “circuitry” are used broadly, and intended to include both hardware implementations of electrical devices and conductors that, when connected and configured, enable the performance of the functions described in the present disclosure, without limitation as to the type of electronic circuits, as well as software implementations of information and instructions that, when executed by a processor, enable the performance of the functions described in the present disclosure.

One or more of the components, steps, features and/or functions illustrated in FIGs. 1–13 may be rearranged and/or combined into a single component, step, feature or function or embodied in several components, steps, or functions. Additional elements, components, steps, and/or functions may also be added without departing from novel features disclosed herein. The apparatus, devices, and/or components illustrated in FIGs. 1–13 may be configured to perform one or more of the methods, features, or steps described herein. The novel algorithms described herein may also be efficiently implemented in software and/or embedded in hardware.

It is to be understood that the specific order or hierarchy of steps in the methods disclosed is an illustration of exemplary processes. Based upon design preferences, it is understood that the specific order or hierarchy of steps in the methods may be rearranged. The accompanying method claims present elements of the various steps in a sample order, and are not meant to be limited to the specific order or hierarchy presented unless specifically recited therein.

The previous description is provided to enable any person skilled in the art to practice the various aspects described herein. Various modifications to these aspects will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other aspects. Thus, the claims are not intended to be limited to the aspects shown herein, but are to be accorded the full scope consistent with the language of the claims, wherein reference to an element in the singular is not intended to mean “one and only one” unless specifically so stated, but rather “one or more. ” Unless specifically stated otherwise, the term “some” refers to one or more. A phrase referring to “at least one of” a list of items refers to any combination of those items, including single members. As an example, “at least one of: a, b, or c” is intended to cover: a; b; c; a and b; a and c; b and c; and a, b and c. All structural and functional equivalents to the elements of the various aspects described throughout this disclosure that are known or later come to be known to those of ordinary skill in the art are expressly incorporated herein by reference and are intended to be encompassed by the claims. Moreover, nothing disclosed herein is intended to be dedicated to the public regardless of whether such disclosure is explicitly recited in the claims. No claim element is to be construed under the provisions of 35 U.S.C. §112 (f) unless the element is expressly recited using the phrase “means for” or, in the case of a method claim, the element is recited using the phrase “step for. ”

Claims

A method of wireless communication at a first scheduling entity, comprising:

determining a sidelink communication mode for sidelink communication between a first user equipment (UE) and a second UE; and

scheduling a transmission of a first sidelink signal from the first UE to the second UE according to the sidelink communication mode, wherein the sidelink communication mode provides a common timing for receiving the first sidelink signal at the second UE and at least one of:

determining a cross link interference (CLI) from a third UE;

receiving a downlink transmission from the first scheduling entity; or

receiving the first sidelink signal and receiving a second sidelink signal from a fourth UE that is associated with a second scheduling entity.
The method of claim 1, wherein the scheduling comprises:

scheduling the first UE to use an uplink transmit timing of the first UE to transmit the first sidelink signal.
The method of claim 2, wherein the first UE and the third UE are associated with the first scheduling entity.
The method of claim 1, wherein the scheduling comprises:

scheduling the first UE to use a downlink receive timing of the first UE to transmit the first sidelink signal.
The method of claim 4, wherein the first UE and the second UE are associated with the first scheduling entity.
The method of claim 1, wherein the scheduling comprises:

scheduling the first UE to use a downlink transmit timing of the first scheduling entity to transmit the first sidelink signal.
The method of claim 6, wherein the second scheduling entity uses the same downlink transmit timing of the first scheduling entity to communicate with the fourth UE.
The method of any of claims 1 to 7, wherein the scheduling comprises at least one of:

transmitting a radio resource control message that indicates the sidelink communication mode;

transmitting a MAC control element that indicates the sidelink communication mode; or

transmitting downlink control information that indicates the sidelink communication mode.
A method of wireless communication at a first user equipment (UE) , comprising:

receiving, from a first scheduling entity, sidelink configuration information of a sidelink connection between the first UE and a second UE;

selecting a sidelink transmission mode based on the sidelink configuration information; and

receiving, from the second UE, a first sidelink signal based on the selected sidelink transmission mode such that the first UE uses a common timing for receiving the first sidelink signal and at least one of:

determining a cross link interference (CLI) from a third UE based on the common timing;

receiving a downlink transmission from the first scheduling entity based on the common timing; or

receiving a second sidelink signal from a fourth UE that is associated with a second scheduling entity based on the common timing.
The method of claim 9, wherein the sidelink configuration information configures the first UE to receive the first sidelink signal and the CLI from the third UE in a same symbol.
The method of claim 10, wherein the first UE and the third UE are associated with the first scheduling entity.
The method of claim 9, wherein the sidelink configuration information configures the first UE to receive the first sidelink signal and the downlink transmission from the first scheduling entity in a same symbol.
The method of claim 12, wherein the first UE and the second UE are associated with the first scheduling entity.
The method of claim 9, wherein the sidelink configuration information configures the first UE to receive the first sidelink signal and the second sidelink signal from the fourth UE in a same symbol.
The method of claim 14, wherein the second scheduling entity uses the same downlink transmit timing of the first scheduling entity to communicate with the fourth UE.
The method of any of claims 9 to 15, wherein receiving the sidelink configuration information comprises at least one of:

receiving a radio resource control message that includes the sidelink configuration information;

receiving a MAC control element that includes the sidelink configuration information; or

receiving downlink control information that includes the sidelink configuration information.
A first scheduling entity for wireless communication, comprising:

a communication interface configured for wireless communication;

a memory; and

a processor operatively coupled with the communication interface and the memory,

wherein the processor and the memory are configured to:

determine a sidelink communication mode for sidelink communication between a first user equipment (UE) and a second UE; and

schedule a transmission of a first sidelink signal from the first UE to the second UE according to the sidelink communication mode, wherein the sidelink communication mode provides a common timing for receiving the first sidelink signal at the second UE and at least one of:

determining a cross link interference (CLI) from a third UE;

receiving a downlink transmission from the first scheduling entity; or

receiving a second sidelink signal from a fourth UE that is associated with a second scheduling entity.
The first scheduling entity of claim 17, wherein the processor and the memory are further configured to:

schedule the first UE to use an uplink transmit timing of the first UE to transmit the first sidelink signal.
The first scheduling entity of claim 18, wherein the first UE and the third UE are associated with the first scheduling entity.
The first scheduling entity of claim 17, wherein the processor and the memory are further configured to:

schedule the first UE to use a downlink receive timing of the first UE to transmit the first sidelink signal.
The first scheduling entity of claim 20, wherein the first UE and the second UE are associated with the first scheduling entity.
The first scheduling entity of claim 17, wherein the processor and the memory are further configured to:

schedule the first UE to use a downlink transmit timing of the first scheduling entity to transmit the first sidelink signal.
The first scheduling entity of claim 22, wherein the second scheduling entity uses the same downlink transmit timing of the first scheduling entity to communicate with the fourth UE.
The first scheduling entity of any of claims 17 to 23, wherein the processor and the memory are further configured to, at least one of:

transmit a radio resource control message that indicates the sidelink communication mode;

transmit a MAC control element that indicates the sidelink communication mode; or

transmit downlink control information that indicates the sidelink communication mode.
A first user equipment (UE) for wireless communication, comprising:

a communication interface configured for wireless communication;

a memory; and

a processor operatively coupled with the communication interface and the memory,

wherein the processor and the memory are configured to:

receive, from a first scheduling entity, sidelink configuration information of a sidelink connection between the first UE and a second UE;

select a sidelink transmission mode based on the sidelink configuration information; and

receive, from the second UE, a first sidelink signal based on the selected sidelink transmission mode such that the first UE uses a common timing for receiving the first sidelink signal and at least one of:

determining a cross link interference (CLI) from a third UE based on the common timing;

receiving a downlink transmission from the first scheduling entity based on the common timing; or

receiving a second sidelink signal from a fourth UE that is associated with a second scheduling entity based on the common timing.
The first UE of claim 25, wherein the sidelink configuration information configures the first UE to receive the first sidelink signal and determine the CLI from the third UE in a same symbol.
The first UE of claim 26, wherein the first UE and the third UE are associated with the first scheduling entity.
The first UE of claim 25, wherein the sidelink configuration information configures the first UE to receive the first sidelink signal and the downlink transmission from the first scheduling entity in a same symbol.
The first UE of claim 28, wherein the first UE and the second UE are associated with the first scheduling entity.
The first UE of claim 25, wherein the sidelink configuration information configures the first UE to receive the first sidelink signal and the second sidelink signal from the fourth UE in a same symbol.
The first UE of claim 30, wherein the second scheduling entity uses the same downlink transmit timing of the first scheduling entity to communicate with the fourth UE.
The first UE of any of claims 25 to 31, wherein the processor and the memory are further configured to receive at least one of:

a radio resource control message that includes the sidelink configuration information;

a MAC control element that includes the sidelink configuration information; or

downlink control information that includes the sidelink configuration information.
A first scheduling entity for wireless communication, comprising:

means for determining a sidelink communication mode for sidelink communication between a first user equipment (UE) and a second UE; and

means for scheduling a transmission of a sidelink signal from the first UE to the second UE according to the sidelink communication mode, wherein the sidelink communication mode provides a common timing for receiving the first sidelink signal at the second UE and at least one of:

determining a cross link interference (CLI) from a third UE;

receiving a downlink transmission from the first scheduling entity; or

receiving a second sidelink signal from a fourth UE that is associated with a second scheduling entity.
A first user equipment (UE) for wireless communication, comprising:

means for receiving, from a first scheduling entity, sidelink configuration information of a sidelink connection between the first UE and a second UE;

means for selecting a sidelink transmission mode based on the sidelink configuration information; and

means for receiving, from the second UE, a first sidelink signal based on the selected sidelink transmission mode such that the first UE uses a common timing for receiving the first sidelink signal and at least one of:

determining a cross link interference (CLI) from a third UE based on the common timing;

receiving a downlink transmission from the first scheduling entity based on the common timing; or

receiving a second sidelink signal from a fourth UE that is associated with a second scheduling entity based on the common timing.
A computer-readable storage medium stored with executable code for wireless communication, the executable code causes a first scheduling entity to:

determine a sidelink communication mode for sidelink communication between a first user equipment (UE) and a second UE; and

schedule a transmission of a sidelink signal from the first UE to the second UE according to the sidelink communication mode, wherein the sidelink communication mode provides a common timing for receiving the first sidelink signal at the second UE and at least one of:

determining a cross link interference (CLI) from a third UE;

receiving a downlink transmission from the first scheduling entity; or

receiving a second sidelink signal from a fourth UE that is associated with a second scheduling entity.
A computer-readable storage medium stored with executable code for wireless communication, the executable code causes a first user equipment (UE) to:

receive, from a first scheduling entity, sidelink configuration information of a sidelink connection between the first UE and a second UE;

select a sidelink transmission mode based on the sidelink configuration information; and

receive, from the second UE, a first sidelink signal based on the selected sidelink transmission mode such that the first UE uses a common timing for receiving the first sidelink signal and at least one of:

determining a cross link interference (CLI) from a third UE based on the common timing;

receiving a downlink transmission from the first scheduling entity based on the common timing; or

receiving a second sidelink signal from a fourth UE that is associated with a second scheduling entity based on the common timing.