Patent Application
20240023156
Aspects of the present disclosure generally relate to wireless communications, and more particularly to techniques and apparatuses for sidelink communications.
Wireless communication systems are widely deployed to provide various telecommunication services such as telephony, video, data, messaging, and broadcasting. Typical wireless communication systems may employ multiple-access technologies capable of supporting communication with multiple users by sharing available system resources (e.g., bandwidth, transmit power, and/or the like). Examples of such multiple-access technologies include code division multiple access (CDMA) systems, time division multiple access (TDMA) systems, frequency-division multiple access (FDMA) systems, orthogonal frequency-division multiple access (OFDMA) systems, single-carrier frequency-division multiple access (SC-FDMA) systems, time division synchronous code division multiple access (TD-SCDMA) systems.
A wireless communication network may include a number of base stations (BSs) that can support communication for a number of user equipments (UEs). A user equipment (UE) may communicate with a base station (BS) via downlink and uplink. The downlink (or forward link) refers to a communication link from the BS to the UE, and the uplink (or reverse link) refers to a communication link from the UE to the BS. As will be described in more detail herein, a BS may also be referred to as a Node B, a gNB, an access point (AP), a radio head, a transmit receive point (TRP), a New Radio (NR) BS, a 5G Node B, and/or the like.
The above multiple access technologies have been adopted in various telecommunication standards to provide a common protocol that enables different user equipment to communicate on a municipal, national, regional, and even global level. LTE/LTE-Advanced is a set of enhancements to the Universal Mobile Telecommunications System (UMTS) mobile standard promulgated by the Third Generation Partnership Project (3GPP). New Radio (NR), which may also be referred to as 5G, is a set of enhancements to the LTE mobile standard promulgated by the Third Generation Partnership Project (3GPP). NR is designed to by better support mobile broadband Internet access by improving spectral efficiency, lowering costs, improving services, making use of new spectrum, and better integrating with other open standards using orthogonal frequency division multiplexing (OFDM) with a cyclic prefix (CP) (CP-OFDM) on the downlink (DL), using CP-OFDM and/or SC-FDM (e.g., also known as discrete Fourier transform spread OFDM (DFT-s-OFDM)) on the uplink (UL), as well as supporting beamforming, multiple-input multiple-output (MIMO) antenna technology, and carrier aggregation.
However, as the demand for mobile broadband access continues to increase, there exists a need for further improvements in wireless communications. Preferably, these improvements should be applicable to LTE and/or NR, and/or also to other multiple access technologies and the telecommunication standards that employ these technologies.
In some aspects of the present disclosure, a method for wireless communication is disclosed, the method being performed by a user equipment (UE), may include determining a first set of slots within a sidelink resource pool, determining a set of candidate single-slot resources, each candidate single-slot resource associated with a slot of the first set of slots, determining a second set of slots within the sidelink resource pool based on the first set of slots, wherein the first set of slots and the second set of slots do not overlap, monitoring for one or more transmissions comprising control information in each slot of the second set of slots, wherein the monitoring comprises using a receive beam, selectively excluding, based on the control information, one or more resources from the set of candidate single-slot resources, and transmitting a sidelink transmission in one or more remaining resources of the set of candidate single-slot resources.
In some aspects of the present disclosure, an apparatus for wireless communication may include means for determining a first set of slots within a sidelink resource pool, means for determining a set of candidate single-slot resources, each candidate single-slot resource associated with a slot of the first set of slots, means for determining a second set of slots within the sidelink resource pool based on the first set of slots, wherein the first set of slots and the second set of slots do not overlap, means for monitoring for one or more transmissions comprising control information in each slot of the second set of slots, wherein the monitoring comprises using a receive beam, means for selectively excluding, based on the control information, one or more resources from the set of candidate single-slot resources, and means for transmitting a sidelink transmission in one or more remaining resources of the set of candidate single-slot resources.
In some aspects of the present disclosure, an apparatus for wireless communication may include a memory and one or more processors coupled to the memory, the memory and the one or more processors may be configured to determine a first set of slots within a sidelink resource pool, determine a set of candidate single-slot resources, each candidate single-slot resource associated with a slot of the first set of slots, determine a second set of slots within the sidelink resource pool based on the first set of slots, wherein the first set of slots and the second set of slots do not overlap, monitor for one or more transmissions comprising control information in each slot of the second set of slots, wherein the monitoring comprises using a receive beam, selectively exclude, based on the control information, one or more resources from the set of candidate single-slot resources, and transmit a sidelink transmission in one or more remaining resources of the set of candidate single-slot resources.
In some aspects of the present disclosure, a non-transitory computer-readable medium may store one or more instructions for wireless communication. The one or more instructions, when executed by one or more processors, for instance one or more processors of a UE, may cause the one or more processors to determine a first set of slots within a sidelink resource pool, determine a set of candidate single-slot resources, each candidate single-slot resource associated with a slot of the first set of slots, determine a second set of slots within the sidelink resource pool based on the first set of slots, wherein the first set of slots and the second set of slots do not overlap, monitor for one or more transmissions comprising control information in each slot of the second set of slots, wherein the monitoring comprises using a receive beam, selectively exclude, based on the control information, one or more resources from the set of candidate single-slot resources, and transmit a sidelink transmission in one or more remaining resources of the set of candidate single-slot resources.
The foregoing has outlined rather broadly the features and technical advantages of examples according to the disclosure in order that the detailed description that follows may be better understood. Additional features and advantages will be described hereinafter. The conception and specific examples disclosed may be readily utilized as a basis for modifying or designing other structures for carrying out the same purposes of the present disclosure. Such equivalent constructions do not depart from the scope of the appended claims. Characteristics of the concepts disclosed herein, both their organization and method of operation, together with associated advantages will be better understood from the following description when considered in connection with the accompanying figures. Each of the figures is provided for the purposes of illustration and description, and not as a definition of the limits of the claims.
So that the above-recited aspects of the present disclosure can be understood in detail, a more particular description, may be had by reference to aspects, some of which are illustrated in the appended drawings. It is to be noted, however, that the appended drawings illustrate only certain typical aspects of this disclosure and are therefore not to be considered limiting of its scope, for the description may admit to other equally effective aspects. The same reference numbers in different drawings may identify the same or similar elements.
Various aspects of the present disclosure are described in more detail hereinafter with reference to the accompanying drawings. This disclosure may, however, be implemented in many different forms and should not be construed as limited to any specific structure or function presented throughout this disclosure. Rather, these aspects are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the present disclosure to those skilled in the art. Based on the teachings herein one skilled in the art should appreciate that the scope of the present disclosure is intended to cover any aspect of the present disclosure disclosed herein, whether implemented independently of or combined with any other aspect of the present disclosure. For example, an apparatus may be implemented or a method may be practiced using any number of the aspects set forth herein. In addition, the scope of the present disclosure is intended to cover such an apparatus or method which is practiced using other structure, functionality, or structure and functionality in addition to or other than the various aspects of the present disclosure set forth herein. It should be understood that any aspect of the present disclosure disclosed herein may be implemented by one or more elements of a claim.
Several aspects of telecommunication systems will now be presented with reference to various apparatuses and techniques. These apparatuses and techniques will be described in the following detailed description and illustrated in the accompanying drawings by various blocks, modules, components, circuits, steps, processes, algorithms, and/or the like (collectively referred to as “elements”). These elements may be implemented using hardware, software, or combinations thereof. Whether such elements are implemented as hardware or software depends upon the particular application and design constraints imposed on the overall system.
It should be noted that while aspects may be described herein using terminology commonly associated with 3G and/or 4G wireless technologies, aspects of the present disclosure can be applied in other generation-based communication systems, such as 5G and later, including NR technologies and Open RAN (O-RAN) technologies.
A BS may provide communication coverage for a macro cell, a pico cell, a femto cell, and/or another type of cell. A macro cell may cover a relatively large geographic area (e.g., several kilometers in radius) and may allow unrestricted access by UEs with service subscription. A pico cell may cover a relatively small geographic area and may allow unrestricted access by UEs with service subscription. A femto cell may cover a relatively small geographic area (e.g., a home) and may allow restricted access by UEs having association with the femto cell (e.g., UEs in a closed subscriber group (CSG)). A BS for a macro cell may be referred to as a macro BS. A BS for a pico cell may be referred to as a pico BS. A BS for a femto cell may be referred to as a femto BS or a home BS. In the example shown in
Wireless network 100 may also include relay stations. A relay station is an entity that can receive a transmission of data from an upstream station (e.g., a BS or a UE) and send a transmission of the data to a downstream station (e.g., a UE or a BS). A relay station may also be a UE that can relay transmissions for other UEs. In the example shown in
Wireless network 100 may be a heterogeneous network that includes BSs of different types, e.g., macro BSs, pico BSs, femto BSs, relay BSs, and/or the like. These different types of BSs may have different transmit power levels, different coverage areas, and different impacts on interference in wireless network 100. For example, macro BSs may have a high transmit power level (e.g., 5 to 40 Watts) whereas pico BSs, femto BSs, and relay BSs may have lower transmit power levels (e.g., 0.1 to 2 Watts).
A network controller 130 may couple to one or more (e.g., a set of) BSs and may provide coordination and control for these BSs. Network controller 130 may communicate with the BSs via a backhaul. The BSs may also communicate with one another, e.g., directly or indirectly via a wireless or wireline backhaul.
UEs 120 (e.g., 120a, 120b, 120c, 120d, 120e, and/or the like) may be dispersed throughout wireless network 100, and each UE may be stationary or mobile. A UE may communicate with one or more BSs in wireless network 100, may communicate directly with another UE (e.g., UE 120a and UE 120e, as illustrated in
In some cases, two or more subordinate entities (e.g., UEs) may communicate with each other using sidelink signals. Real-world applications of such sidelink communications may include public safety, proximity services, UE-to-network relaying, vehicle-to-everything (V2X) communications, Internet of Everything (IoE) communications, Internet-of-Things (IoT) communications, mission-critical mesh, and/or various other suitable applications. Generally, a sidelink signal may refer to a signal communicated from one subordinate entity (e.g., UE1) to another subordinate entity (e.g., UE2) without relaying that communication through a scheduling entity (e.g., UE or BS), even though the scheduling entity may be utilized for scheduling and/or control purposes. In some examples, the sidelink signals may be communicated using a licensed spectrum (unlike wireless local area networks, which may use an unlicensed spectrum).
A UE may also be referred to as an access terminal, a terminal, a mobile station, a subscriber unit, a station, and/or the like. A UE may be a cellular phone (e.g., a smart phone), a personal digital assistant (PDA), a wireless modem, a wireless communication device, a handheld device, a laptop computer, a cordless phone, a wireless local loop (WLL) station, a tablet, a camera, a gaming device, a netbook, a smartbook, an ultrabook, a medical device or equipment, biometric sensors/devices, wearable devices (smart watches, smart clothing, smart glasses, smart wrist bands, smart jewelry (e.g., smart ring, smart bracelet)), an entertainment device (e.g., a music or video device, or a satellite radio), a vehicular component or sensor, smart meters/sensors, industrial manufacturing equipment, a global positioning system device, or any other suitable device that is configured to communicate via a wireless or wired medium.
Some UEs may be considered as machine-type communication (MTC) or evolved or enhanced machine-type communication (eMTC) UEs. MTC and eMTC UEs include, for example, robots, drones, remote devices, sensors, meters, monitors, location tags, and/or the like, that may communicate with a base station, another device (e.g., remote device), or some other entity. A wireless node (e.g., UE, BS, or the like) may provide, for example, connectivity for or to a network (e.g., a wide area network such as Internet or a cellular network) via a wired or wireless communication link. Some UEs may be considered as Internet-of-Things (IoT) devices, and/or may be implemented as NB-IoT (narrowband internet of things) devices. Some UEs may be considered as a Customer Premises Equipment (CPE). UE 120 may be included inside a housing that houses components of UE 120, such as processor components, memory components, and/or the like.
In general, any number of wireless networks may be deployed in a given geographic area. Each wireless network may support a particular radio access technology (RAT) and may operate on one or more frequencies. A RAT may also be referred to as a radio technology, an air interface, and/or the like. A frequency may also be referred to as a carrier, a frequency channel, and/or the like. Each frequency may support a single RAT in a given geographic area in order to avoid interference between wireless networks of different RATs. In some cases, NR or 5G RAT networks may be deployed.
As described herein, a wireless node (which may be referred to as a node, a network node, a network entity, or a wireless node) may include, be, or be included in (e.g., be a component of) a base station (e.g., any base station described herein), a UE (e.g., any UE described herein), a network controller, an apparatus, a device, a computing system, an integrated access and backhauling (IAB) node, a distributed unit (DU), a central unit (CU), a remote unit (RU), and/or another processing entity configured to perform any of the techniques described herein. For example, a network node may be a UE. As another example, a network node may be a base station or network entity. As another example, a first network node may be configured to communicate with a second network node or a third network node. In one aspect of this example, the first network node may be a UE, the second network node may be a base station, and the third network node may be a UE. In another aspect of this example, the first network node may be a UE, the second network node may be a base station, and the third network node may be a base station. In yet other aspects of this example, the first, second, and third network nodes may be different relative to these examples. Similarly, reference to a UE, base station, apparatus, device, computing system, or the like may include disclosure of the UE, base station, apparatus, device, computing system, or the like being a network node. For example, disclosure that a UE is configured to receive information from a base station also discloses that a first network node is configured to receive information from a second network node. Consistent with this disclosure, once a specific example is broadened in accordance with this disclosure (e.g., a UE is configured to receive information from a base station also discloses that a first network node is configured to receive information from a second network node), the broader example of the narrower example may be interpreted in the reverse, but in a broad, open-ended way. The example above where a UE is configured to receive information from a base station also discloses that a first network node is configured to receive information from a second network node, where the first network node may refer to a first UE, a first base station, a first apparatus, a first device, a first computing system, a first set of one or more one or more components, a first processing entity, or the like configured to receive the information; and the second network node may refer to a second UE, a second base station, a second apparatus, a second device, a second computing system, a second set of one or more components, a second processing entity, or the like.
As described herein, communication of information (e.g., any information, signal, or the like) may be described in various aspects using different terminology. Disclosure of one communication term includes disclosure of other communication terms. For example, a first network node may be described as being configured to transmit information to a second network node. In this example and consistent with this disclosure, when the first network node is configured to transmit information to the second network node, the first network node may be configured to provide, send, output, communicate, or transmit information to the second network node. Similarly, in this example and consistent with this disclosure, when the first network node is configured to transmit information to the second network node, the second network node may be configured to receive, obtain, or decode the information that is provided, sent, output, communicated, or transmitted by the first network node.
As shown in
As indicated above,
At base station 110, a transmit processor 220 may receive data from a data source 212 for one or more UEs, select one or more modulation and coding schemes (MCS) for each UE based on channel quality indicators (CQIs) received from the UE, process (e.g., encode and modulate) the data for each UE based on the MCS(s) selected for the UE, and provide data symbols for all UEs. Transmit processor 220 may also process system information (e.g., for semi-static resource partitioning information (SRPI) and/or the like) and control information (e.g., CQI requests, grants, upper layer signaling, and/or the like) and provide overhead symbols and control symbols. Transmit processor 220 may also generate reference symbols for reference signals (e.g., the cell-specific reference signal (CRS)) and synchronization signals (e.g., the primary synchronization signal (PSS) and secondary synchronization signal (SSS)). A transmit (Tx) multiple-input multiple-output (MIMO) processor 230 may perform spatial processing (e.g., precoding) on the data symbols, the control symbols, the overhead symbols, and/or the reference symbols, if applicable, and may provide T output symbol streams to T modulators (MODs) 232a through 232t. Each modulator 232 (e.g., 232a through 232t) may process a respective output symbol stream (e.g., for OFDM and/or the like) to obtain an output sample stream. Each modulator 232 may further process (e.g., convert to analog, amplify, filter, and upconvert) the output sample stream to obtain a downlink signal. T downlink signals from modulators 232a through 232t may be transmitted via T antennas 234a through 234t, respectively. According to various aspects described in more detail below, the synchronization signals can be generated with location encoding to convey additional information.
At UE 120a, antennas 252a through 252r may receive the downlink signals from base station 110 and/or other base stations, may receive sidelink signals from another UE 120e (e.g., UE 120a may receive sidelink signals from UE 120e and/or vice-versa) and may provide received signals to demodulators (DEMODs) 254a through 254r, respectively. Each demodulator 254 (e.g., 254a through 254r) may condition (e.g., filter, amplify, downconvert, and digitize) a received signal to obtain input samples. Each demodulator 254 may further process the input samples (e.g., for OFDM and/or the like) to obtain received symbols. A MIMO detector 256 may obtain received symbols from all R demodulators 254a through 254r, perform MIMO detection on the received symbols if applicable, and provide detected symbols. A receive processor 258 may process (e.g., demodulate and decode) the detected symbols, provide decoded data for UE 120a to a data sink 260, and provide decoded control information and system information to a controller/processor 280. A channel processor may identify reference signal received power (RSRP), received signal strength indicator (RSSI), reference signal received quality (RSRQ), channel quality indicator (CQI), and/or the like. In some aspects, one or more components of UE 120a and/or UE 120e may be included in a housing.
On the uplink or a sidelink, at UE 120a, a transmit processor 264 may receive and process data from a data source 262 and control information (e.g., for reports comprising RSRP, RSSI, RSRQ, CQI, and/or the like) from controller/processor 280. Transmit processor 264 may also generate reference symbols for one or more reference signals. The symbols from transmit processor 264 may be precoded by a Tx MIMO processor 266 if applicable, further processed by modulators 254a through 254r (e.g., for DFT-s-OFDM, CP-OFDM, and/or the like), and transmitted to base station 110 on the uplink and/or to another UE 120e on the sidelink. At base station 110, the uplink signals from UE 120a, UE 120e, and other UEs may be received by antennas 234 (e.g., 234a through 234t), processed by demodulators 232, detected by a MIMO detector 236 if applicable, and further processed by a receive processor 238 to obtain decoded data and control information sent by UE 120a and/or UE 120e. Receive processor 238 may provide the decoded data to a data sink 239 and the decoded control information to controller/processor 240. Base station 110 may include communication unit 244 and communicate to network controller 130 via communication unit 244. Network controller 130 may include communication unit 294, controller/processor 290, and memory 292.
Controller/processor 240 of base station 110, controller/processor 280 of UE 120a, and/or any other component(s) of
In some aspects, a UE 120 (e.g., UE 120a and/or UE 120e) may include means for determining a first set of slots within a sidelink resource pool, means for determining a set of candidate single-slot resources, each candidate single-slot resource associated with a slot of the first set of slots, means for determining a second set of slots within the sidelink resource pool based on the first set of slots, wherein the first set of slots and the second set of slots do not overlap, means for monitoring for one or more transmissions comprising control information in each slot of the second set of slots, wherein the monitoring comprises using a receive beam, means for selectively excluding, based on the control information, one or more resources from the set of candidate single-slot resources, and/or means for transmitting a sidelink transmission in one or more remaining resources of the set of candidate single-slot resources.
As indicated above,
In some aspects, a UE (e.g., UE 120a, UE 120e, and/or the like) may transmit, to another UE (e.g., UE 120a, UE 120e, and/or the like) on a sidelink, one or more sidelink communications in a transmission period, which may include one or more slots included in frame structure 300. In some aspects, the other UE may receive the one or more sidelink communications, may generate feedback for the one or more sidelink communications, may incorporate the feedback into one or more feedback communications, and may transmit, to the UE on the sidelink, the one or more feedback communications in one or more symbols and/or slots included in a reporting period, in frame structure 300, configured for the sidelink.
While some techniques are described herein in connection with frames, subframes, slots, and/or the like, these techniques may equally apply to other types of wireless communication structures, which may be referred to using terms other than “frame,” “subframe,” “slot,” and/or the like in 5G NR. In some aspects, a wireless communication structure may refer to a periodic time-bounded communication unit defined by a wireless communication standard and/or protocol.
As indicated above,
In some aspects of the present disclosure, multiple deployment scenarios for sidelink communication in terms of a relationship between the sidelink communication and an overlaid cellular network may exist. In one aspect, devices (e.g., wireless devices, UEs) involved in sidelink communications may be under a coverage of an overlaid cellular network (e.g., a NR network). The overlaid cellular network may control sidelink communications, for instance, the overlaid network may schedule the sidelink transmissions. In some aspects, in-coverage operation may sometimes use (or be referred to as) a resource-allocation mode 1 (e.g., a NR mode 1 SL). In case of the in-coverage operation, sidelink communications may share carrier frequency with the overlaid cellular network. Alternatively, sidelink communications may take place on a sidelink-specific carrier frequency different from carrier frequency (or carrier frequencies) of the overlaid cellular network. In another aspect, the devices involved in the sidelink communications may not be within the coverage of an overlaid cellular network. In some aspects, out-of-coverage operation may sometimes use (or be referred to as) a resource-allocation mode 2 (e.g., a NR mode 2 SL). In out-of-coverage operation, decision on sidelink transmission may be determined by a device (e.g., a transmitting device, a Tx UE) itself based, for instance, on sensing and resource selection procedure. Such decision may include determining a set of resources for use in the sidelink transmission.
In some aspects of the present disclosure, sidelink transmission (e.g., NR sidelink transmission) may be based on a multiplexing technique such as OFDM. A device which is configured for sidelink transmission may be configured (e.g., pre-configured, statically or dynamically configured by the network) with a sidelink resource pool. A sidelink resource pool may define, among others, overall time/frequency resources that may be used for sidelink communication within a carrier. In a time domain, a resource pool may comprise a set of slots repeated over a resource pool period (e.g., a resource pool period associated with a resources pool such as in NR). Thus, in the time domain, a resource pool may be defined by specifying, among others, a configurable resource-pool period, a configurable set of sidelink slots within the resource-pool period, and/or the like. Expressed differently, in some aspects, a resource-pool may have a slot-based granularity in the time domain. In a frequency domain, the resource pool may comprise a set of consecutive subchannels, where a subchannel may be composed of a number of resource blocks (e.g., a number of consecutive resource blocks, for instance, 10, 15, 20, 25, 50, 75 or 100 consecutive resource blocks) and/or a configurable resource-pool bandwidth corresponding to a set of consecutive subchannels. In some aspects, the resource pool may be defined by additionally specifying a frequency-domain location of a subchannel of the resource pool.
In some aspects of the present disclosure, a transmitting device (e.g., a Tx UE) may facilitate a sensing and resource-selection procedure by providing one or more resources-reservation announcements. A resource reservation announcement may provide information (for instance, to other devices) about which set of resources a device (e.g., nearby Tx UE) has selected for future sidelink transmissions. For instance, in some aspects of the present disclosure, a device may reserve resources, for instance, for up to two additional transmissions within a time window corresponding to a number of slots including a current slot (e.g., 32 slots including the current slot). Each of these future transmissions may have the same bandwidth as the transmission in the current slot but may have different frequency-domain locations. Information about such reserved resources may be provided in terms of time offsets (for instance, Δt1 and Δt2) and/or frequency shifts (for instance, Δf1 and Δf2) and may be provided as part a resource reservation within control information (e.g., sidelink control information—SCI, more specifically, 1st stage SCI in NR). In addition, or alternatively, a device may reserve periodically occurring sets of resources for a sidelink transmission. Each of such periodically occurring set of resources may have the same structure (bandwidth, frequency shifts, and/or relative time offsets) as an initial transmission and may periodically occur with a period Tp. In some aspects, the period Tp may range from 1 ms up to 900 ms. In some aspects, a set of allowed periods Tp may be configured by higher layers (e.g., via RRC signaling such as sl-ResourceReservePeriodList message in NR). In some aspects of the present disclosure, control information (e.g., SCI) may comprise one or more of a time resource assignment (TRA) field, a frequency resource assignment (FRA) field, or a resource reservation interval (RRI) field.
In accordance with one or more aspects of the present disclosure, a device (e.g., a UE 120a, 120e, for instance, a Tx UE) may perform a sensing and resource (e.g., one or more time resources and/or one or more frequency resources) selection procedure by which the device may select a set of resources to use for sidelink transmission based on resource reservations (e.g., in control information, for instance, TRA/FRA/RRI fields in SCI) announced by other devices. A sidelink transmission may be assigned a delay budget implying that this sidelink transmission is expected to be transmitted within a certain time window. Alternatively, or in addition, the sidelink transmission may be assigned a priority.
According to an aspect of the present disclosure, a device (e.g., a UE 120a, 120e, a Tx UE or the like) may perform full sensing.
For instance, as shown in
Upon obtaining the trigger in the slot 402, the device may, based on received reservations transmitted by nearby devices, determine which resources are available for its own sidelink transmission. A candidate resource (e.g., candidate single-slot resource, such as Rx,y in NR) may be defined as a set of a number (e.g., LsubCH in NR) contiguous sub-channels (e.g., with a sub-channel x+j in a slot ty in a sidelink resource pool, where j=0, . . . , LsubCH−1). In some aspects, the number LsubCH may refer to a number of sub-channels to be used for a sidelink transmission in a slot and may be configured by higher layers (e.g., via RRC signaling). The device may, from a set of candidate resources (e.g., candidate single-slot resources) within the resource selection window 406, determine to selectively exclude resource 416 (e.g., contiguous LsubCH resources, such as resource Rx,y in NR) in view of an overlap with the reserved resource 410. In a similar manner, the device may determine to exclude any candidate resource (not shown) from the set of candidate resources in view of an overlap with any resource reserved by any nearby UEs (determined by the device by sensing/monitoring for transmissions/reservations by nearby UEs).
A physical (PHY) layer of the device may then provide a set of available resources that the device may use to select one or more resources for the sidelink transmission (i.e., the set of remaining candidate resources, which may be sometimes referred to as SA) to a medium access control (MAC) layer. Thereupon, the MAC layer may select one or more resources to be used by the sidelink transmission and effectuate the sidelink transmission in the selected one or more resources by the PHY layer (not shown in
In accordance with an aspect of the present disclosure, a device may intend to transmit multiple transport blocks (TBs).
In addition, RRI in SCI of a sidelink transmission may reserve a set of periodic resources for sidelink transmissions of multiple TBs. For instance, the initial transmission of the first TB in the resource 502 may reserve, by using RRI in its SCI, a periodic resource, such as a resource 510 (shown in
In one or more aspects of the present disclosure, partial sensing may be used to reduce power consumption of a device (e.g., a UE 120a, 120e, a Tx UE or the like) in contrast to the aforementioned full sensing. To avoid sensing the channel all the time (e.g., during the entire sensing window 404 shown in
As described above, according to an aspect of the present disclosure, a device (e.g., a UE 120a, 120e, a Tx UE or the like) may perform periodic-based partial sensing (PBPS).
In one aspect of the present disclosure, in PBPS, the device may perform sensing only in sensing occasions having a periodic relationship with slots comprised in the set 604. For instance, the device may perform sensing in a set of slots 606. The set of slots 606 may be composed of slots having a certain time offset to slots in the set of candidate slots 604. Such offset may be equal to a periodicity of sidelink transmissions (by nearby devices) which may be expected by the device, for example, based on various configurations. Such configurations may include a periodicity Preserve which may be indicated by nearby devices in one or more RRIs in SCIs. In some aspects of the present disclosure, the periodicity may only assume values from a set of allowed periodicities configured by higher layers (e.g., via RRC signaling such as sl-ResourceReservePeriodList message in NR). Thus, to determine resources in the candidate set 604 which are reserved by nearby devices, the device may need to only sense the channel in a number of slots (e.g., a set of slots having a relationship k×Preserve slots, with k being a positive integer) prior to each slot in the candidate set 604. The device may perform such sensing for each expected periodicity (e.g., each configured periodicity Preserve).
Referring to
As described above, according to aspects of the present disclosure, a device (e.g., a UE 120a, 120e, a Tx UE or the like) may perform contiguous partial sensing (CPS).
In one aspect of the present disclosure, in CPS, the device may perform sensing only in sensing occasions associated with reservations for retransmissions. For instance, the device may perform sensing in a contiguous partial sensing window defined by boundaries 706a and 706b. The boundaries 706a and 706b may be determined having regard to control information (e.g., SCI as described in the context of resources 502 and 510 in
In one or more aspects of the present disclosure, the device may be configured (e.g., pre-configured), for instance, based on a sidelink resource pool, to perform full sensing only, partial sensing (e.g., PBPS and/or CPS) only, random resource selection only, or any combination thereof. The resource pool may be, in some aspects, an SL mode 2 Tx resource pool in NR. PBPS may be for used for detecting periodic reservations (e.g., in control information such as SCI) by nearby devices. PBPS may be used based on a configuration (e.g., a higher layer parameter, for instance, by RRC signaling, such as sl-MultiReserveResource in NR) of a resource pool. CPS may be used for detecting aperiodic reservations (e.g., in control information such as SCI) of nearby devices. Partial sensing (PBPS and/or CPS) may be used based on a configuration (e.g., a higher layer parameter, for instance, by RRC signaling, such as sl-multiTBReserve in NR) of a resource pool. In some aspects, if the device intends to perform an aperiodic sidelink transmission with a single TB, the device may perform PBPS and CPS (if reserving multiple resources is enabled in a resource pool, e.g., by a higher layer parameter, for instance, by RRC signaling, such as by sl-MultiReserveResource) or CPS only (if reserving multiple resources is disabled). In addition, in some aspects, if the device determines to perform a periodic sidelink transmission with multiple TBs, the device may perform both, PBPS and CPS (if reserving multiple resources is enabled in a resource pool, e.g., by a higher layer parameter, for instance, by RRC signaling, such as by sl-MultiReserveResource). In the case in which the device performs both, PBPS and CPS, the device may combine sensing results from PBPS and CPS to determine available resources (e.g., a set of available resources SA in NR to be reported to the MAC layer).
In accordance with various aspects described above, a resource selection window (e.g., the resource selection window 406 in
In accordance with various aspects described above, sensing methods, for instance, full sensing or partial sensing methods (e.g., PBPS, CPS) may be designed for sensing (e.g., monitoring) in a sub-6 GHz channel (e.g., in FR1 in NR). In one or more aspects of the present disclosure, sensing (e.g., monitoring) described in aforementioned methods may advantageously use a receive beam, for instance, when operating in a millimeter wave channel (e.g., in FR2 in NR). However, aspects of the present disclosure are not limited to use of millimeter waves for sensing (e.g., not limited to use of a receive beam in a millimeter wave channel).
Beamforming, which may also be referred to as spatial filtering, directional transmission, or directional reception, is a signal processing technique that may be used at a transmitting device or a receiving device (e.g., a base station 110 or a UE 120a, 120b, 120c, 120e) to shape or steer an antenna beam (e.g., a transmit beam or receive beam) along a spatial path between the transmitting device and the receiving device. An antenna beam (e.g., a transmit beam or receive beam) may also be referred to as a Transmission Configuration Indicator (TCI) state and/or spatial relation. Beamforming may be achieved by combining the signals communicated via antenna elements of an antenna array such that signals propagating at particular orientations with respect to an antenna array experience constructive interference while others experience destructive interference. The adjustment of signals communicated via the antenna elements may include a transmitting device or a receiving device applying certain amplitude and phase offsets to signals carried via each of the antenna elements associated with the device. The adjustments associated with each of the antenna elements may be defined by a beamforming weight set associated with a particular orientation (e.g., with respect to the antenna array of the transmitting device or receiving device, or with respect to some other orientation).
At step 840a, the UE, e.g., via a suitable PHY layer routine, may determine, as described elsewhere herein (cf.
At step 840b, the UE, e.g., via a suitable PHY layer routine, may determine, as described elsewhere herein (cf.
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In one or more aspects of the present disclosure, in process 1000, transmitting the sidelink transmission may comprise using a transmit beam. The receive beam used for sensing may be determined based on the transmit beam. In some aspects, the transmit beam and the receive beam may be both aligned at a propagation path (e.g., the LOS propagation path 922). Such alignment may be advantageous to reduce interference with a UE (e.g., the UE 918) located substantially within the propagation path. In some aspects, the transmit beam and the receive beam may be directed in opposite directions (e.g., the transmit beam 908, the receive beam 928). Such orientation may be advantageous to reduce interference with a UE (e.g., a UE 924) located substantially within an extension of the propagation path and transmitting along this propagation path (e.g., the transmit beam 926 of the UE 924).
In one or more of the above aspects, a width of the receive beam used for sensing and a width of the transmit beam may differ (e.g., the receive beam may be wider than the transmit beam). In some aspects, a wider receive beam may increase likelihood that transmissions and/or reservations and/or announcements by nearby devices will be sensed and considered in selection of resources for a sidelink transmission. A narrower transmit beam may, in some aspects, allow to advantageously focus energy of the sidelink transmission towards a receiving device.
In one or more aspects of the present disclosure, as an alternative or in addition to aspects described above, the sidelink transmission may be associated with a priority. For example, a sidelink transmission associated with an emergency (e.g., to report information on an accident, for instance, of a vehicle implementing one or more aspects of the present disclosure) may be associated with a higher priority than a transmission associated with a state of charge of a battery. In some aspects, a width of the receive beam used for sensing may be determined based on the priority (e.g., the width may be a monotonic function of the priority).
In some aspects, the width may be a monotonically non-decreasing function of the priority. In such a case, for example, a higher priority may generally result in a wider receive beam used for sensing. A wider receive beam may advantageously increase likelihood that a higher priority transmission is not disturbed by nearby devices since—due to a wider receive beam—transmissions and/or reservations and/or announcements by nearby devices may be sensed and own transmission on reserved resources may be avoided. In other aspects, the width of a receive beam used for sensing may be a monotonically non-increasing function of the priority. In such a case, for example, a higher priority may generally result in a narrower receive beam used for sensing. A narrower receive beam may advantageously increase likelihood that a higher priority transmission will be assigned any resource for transmission. Due to a narrower receive beam used for sensing—generally less transmissions and/or reservations and/or announcements by nearby devices may be sensed and may lead to less exclusions of candidate resources.
In one or more aspects of the present disclosure, as an alternative or in addition to the aspects described above, a width of the receive beam used for sensing may be determined based on a number of slots in the first set of slots. In some aspects, the width may be a monotonically non-decreasing function of the number of slots in the first set of slots. For example, a low number of slots in the first set of slots may advantageously be associated with a narrow receive beam. Similar as above, a narrower receive beam used for sensing may advantageously increase likelihood that own transmission will be assigned any resources. Less transmissions and/or reservations and/or announcements may be sensed and lead to exclusion of candidate resources of the first set of resources having a limited number of slots. Conversely, a high number of slots in the first set of slots may advantageously be associated with a wider receive beam. A wider receive beam used for sensing may result in more exclusions from the first set of slots due to transmissions and/or reservations and/or announcements by nearby devices which may result in less interference with own transmission. In view of a high number of slots in the first set of slots, more exclusions may not adversely affect likelihood that own transmission will be assigned any resources.
In one or more aspects of the present disclosure, as an alternative or in addition to the aspects described above, slots in the second set of slots may be determined in accordance with PBPS and/or in accordance with CPS. The receive beam used in the monitoring for one or more transmissions may be a first receive beam in slots determined in accordance with PBPS, and a second receive beam in slots determined in accordance with CPS. For example, the first receive beam and the second receive beam may be different. In some aspects, the second receive beam (for CPS-determined slots) may be wider than the first receive beam (for PBPS-determined slots), for instance, since sensing duration may be short, for example, in some aspects, the number of slots sensed for CPS may be less than the number of slots sensed for PBPS, if k≥2.
In one or more aspects of the present disclosure, as an alternative or in addition to the aspects described above, using the receive beam for sensing may comprise obtaining an indication of a receive beam to be used for sensing from a MAC layer. The indication may be obtained, for example, at a PHY layer. The PHY layer may determine a receive beam to be used in sensing based on the indication. In some aspects, the PHY layer may determine to use a receive beam as indicated by the MAC layer. In other aspects, the PHY layer may determine to use a modified (or altered) receive beam relative to a receive beam indicated by the MAC layer, for example, based on information which is available at the PHY layer but is not available at the MAC layer. In one additional aspect, an indication of a relationship between the indicated receive beam and the determined receive beam may be provided to the MAC layer. Such indication may be provided in conjunction with reporting to the MAC layer remaining resources in the set of candidate resources (e.g., a set of available resources SA in NR) by the PHY layer.
In one or more aspects of the present disclosure, as an alternative or in addition to the aspects described above, the receive beam used for sensing may be dynamically determined by a UE. For example, at least one of a direction of the receive beam and/or a width of the receive beam may be dynamically determined by the UE. In some aspects, the act of dynamically determining may refer, for example, to periodically determining, or determining based on a trigger (e.g., based on an internal trigger, upon a trigger received from a base station or other UE, or the like).
In one or more aspects of the present disclosure, as an alternative or in addition to the aspects described above, the UE may be configured to operate at least in part in accordance with one or more Technical Specifications (TS) produced by a third Generation Partnership Project (3GPP).
In the following, several aspects of the present disclosure are presented:
Aspect 2. The method of aspect 1, wherein the transmitting the sidelink transmission comprises using a transmit beam, and wherein the receive beam is determined based on the transmit beam.
The foregoing disclosure provides illustration and description, but is not intended to be exhaustive or to limit the aspects to the precise form disclosed. Modifications and variations may be made in light of the above disclosure or may be acquired from practice of the aspects.
As used herein, the term “component” is intended to be broadly construed as hardware, firmware, or a combination of hardware and software. As used herein, a processor is implemented in hardware, firmware, or a combination of hardware and software.
It will be apparent that systems and/or methods described herein may be implemented in different forms of hardware, firmware, or a combination of hardware and software. The actual specialized control hardware or software code used to implement these systems and/or methods is not limiting of the aspects. Thus, the operation and behavior of the systems and/or methods were described herein without reference to specific software code—it being understood that software and hardware can be designed to implement the systems and/or methods based on the description herein.
Even though particular combinations of features are recited in the claims and/or disclosed in the specification, these combinations are not intended to limit the disclosure of various aspects. In fact, many of these features may be combined in ways not specifically recited in the claims and/or dis-closed in the specification. Although each dependent claim listed below may directly depend on only one claim, the disclosure of various aspects includes each dependent claim in combination with every other claim in the claim set. 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-b, a-c, b-c, and a-b-c, as well as any combination with multiples of the same element (e.g., a-a, a-a-a, a-a-b, a-a-c, a-b-b, a-c-c, b-b, b-b-b, b-b-c, c-c, and c-c-c or any other ordering of a, b, and c).
No element, act, or instruction used herein should be construed as critical or essential unless explicitly described as such. Also, as used herein, the articles “a” and “an” are intended to include one or more items, and may be used interchangeably with “one or more.” Furthermore, as used herein, the terms “set” and “group” are intended to include one or more items (e.g., related items, unrelated items, a combination of related and unrelated items, and/or the like), and may be used interchange-ably with “one or more.” Where only one item is intended, the phrase “only one” or similar language is used. Also, as used herein, the terms “has,” “have,” “having,” and/or the like are intended to be open-ended terms.
As used herein, the phrase “based on” shall not be construed as a reference to a closed set of information, one or more conditions, one or more factors, or the like. In other words, the phrase “based on A” (where “A” may be information, a condition, a factor, or the like) shall be construed as “based at least on A” unless specifically recited differently.
