WO2021191764A1 - Repeated feedback transmission - Google Patents

Abstract

Apparatuses, methods, and systems are disclosed for repeated feedback transmission. One method (900) includes determining (902), at a user equipment, that a location of the user equipment is unknown to the user equipment. The method (900) includes attempting (904) to decode a transport block transmitted on a physical sidelink shared channel. The method (900) includes, in response to unsuccessfully decoding the transport block transmitted on the physical sidelink shared channel, transmitting (906) a negative acknowledgement feedback until a threshold is reached.

Description

REPEATED FEEDBACK TRANSMISSION

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority to United States Patent Application Serial Number 62/993,940 entitled “APPARATUSES, METHODS, AND SYSTEMS FOR PROVIDING HARQ FEEDBACK ON SIDELINK IN ABSENCE OF THE KNOWLEDGE OF ITS GEOGRAPHICAL LOCATION” and filed on March 24, 2020 for Prateek Basu Mallick, which is incorporated herein by reference in its entirety.

FIELD

[0002] The subject matter disclosed herein relates generally to wireless communications and more particularly relates to repeated feedback transmission.

BACKGROUND

[0003] In certain wireless communications networks, a user equipment may not know its geographical location. In such networks, the user equipment may use excess battery power in making transmissions.

BRIEF SUMMARY

[0004] Methods for repeated feedback transmission are disclosed. Apparatuses and systems also perform the functions of the methods. One embodiment of a method includes determining, at a user equipment, that a location of the user equipment is unknown to the user equipment. In some embodiments, the method includes attempting to decode a transport block transmitted on a physical sidelink shared channel. In various embodiments, the method includes, in response to unsuccessfully decoding the transport block transmitted on the physical sidelink shared channel, transmitting a negative acknowledgement feedback until a threshold is reached.

[0005] One apparatus for repeated feedback transmission includes a user equipment. In certain embodiments, the apparatus includes a processor that: determines that a location of the user equipment is unknown to the user equipment; and attempts to decode a transport block transmitted on a physical sidelink shared channel. In various embodiments, the apparatus includes a transmitter that, in response to unsuccessfully decoding the transport block transmitted on the physical sidelink shared channel, transmits a negative acknowledgement feedback until a threshold is reached. BRIEF DESCRIPTION OF THE DRAWINGS

[0006] A more particular description of the embodiments briefly described above will be rendered by reference to specific embodiments that are illustrated in the appended drawings. Understanding that these drawings depict only some embodiments and are not therefore to be considered to be limiting of scope, the embodiments will be described and explained with additional specificity and detail through the use of the accompanying drawings, in which:

[0007] Figure 1 is a schematic block diagram illustrating one embodiment of a wireless communication system for repeated feedback transmission;

[0008] Figure 2 is a schematic block diagram illustrating one embodiment of an apparatus that may be used for repeated feedback transmission;

[0009] Figure 3 is a schematic block diagram illustrating one embodiment of an apparatus that may be used for repeated feedback transmission;

[0010] Figure 4 is a diagram illustrating one embodiment of vehicle directional travel;

[0011] Figure 5 is a diagram illustrating one embodiment of a table indicating capped values for providing NACK feedback corresponding to relative speeds;

[0012] Figure 6 is a diagram illustrating one embodiment of a table indicating capped values for providing NACK feedback corresponding to absolute speeds;

[0013] Figure 7 is a diagram illustrating one embodiment of a table indicating timer values for providing NACK feedback corresponding to relative speeds;

[0014] Figure 8 is a diagram illustrating one embodiment of a table indicating timer values for providing NACK feedback corresponding to absolute speeds; and

[0015] Figure 9 is a flow chart diagram illustrating one embodiment of a method for repeated feedback transmission.

DETAIFED DESCRIPTION

[0016] As will be appreciated by one skilled in the art, aspects of the embodiments may be embodied as a system, apparatus, method, or program product. Accordingly, embodiments may take the form of an entirely hardware embodiment, an entirely software embodiment (including firmware, resident software, micro-code, etc.) or an embodiment combining software and hardware aspects that may all generally be referred to herein as a “circuit,” “module” or “system.” Furthermore, embodiments may take the form of a program product embodied in one or more computer readable storage devices storing machine readable code, computer readable code, and/or program code, referred hereafter as code. The storage devices may be tangible, non-transitory, and/or non-transmission. The storage devices may not embody signals. In a certain embodiment, the storage devices only employ signals for accessing code.

[0017] Certain of the functional units described in this specification may be labeled as modules, in order to more particularly emphasize their implementation independence. For example, a module may be implemented as a hardware circuit comprising custom very-large-scale integration (“VLSI”) circuits or gate arrays, off-the-shelf semiconductors such as logic chips, transistors, or other discrete components. A module may also be implemented in programmable hardware devices such as field programmable gate arrays, programmable array logic, programmable logic devices or the like.

[0018] Modules may also be implemented in code and/or software for execution by various types of processors. An identified module of code may, for instance, include one or more physical or logical blocks of executable code which may, for instance, be organized as an object, procedure, or function. Nevertheless, the executables of an identified module need not be physically located together, but may include disparate instructions stored in different locations which, when joined logically together, include the module and achieve the stated purpose for the module.

[0019] Indeed, a module of code may be a single instruction, or many instructions, and may even be distributed over several different code segments, among different programs, and across several memory devices. Similarly, operational data may be identified and illustrated herein within modules, and may be embodied in any suitable form and organized within any suitable type of data structure. The operational data may be collected as a single data set, or may be distributed over different locations including over different computer readable storage devices. Where a module or portions of a module are implemented in software, the software portions are stored on one or more computer readable storage devices.

[0020] Any combination of one or more computer readable medium may be utilized. The computer readable medium may be a computer readable storage medium. The computer readable storage medium may be a storage device storing the code. The storage device may be, for example, but not limited to, an electronic, magnetic, optical, electromagnetic, infrared, holographic, micromechanical, or semiconductor system, apparatus, or device, or any suitable combination of the foregoing.

[0021] More specific examples (anon-exhaustive list) of the storage device would include the following: an electrical connection having one or more wires, a portable computer diskette, a hard disk, a random access memory (“RAM”), a read-only memory (“ROM”), an erasable programmable read-only memory (“EPROM” or Flash memory), a portable compact disc read only memory (“CD-ROM”), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing. In the context of this document, a computer readable storage medium may be any tangible medium that can contain, or store a program for use by or in connection with an instruction execution system, apparatus, or device.

[0022] Code for carrying out operations for embodiments may be any number of lines and may be written in any combination of one or more programming languages including an object oriented programming language such as Python, Ruby, Java, Smalltalk, C++, or the like, and conventional procedural programming languages, such as the "C" programming language, or the like, and/or machine languages such as assembly languages. The code may execute entirely on the user's computer, partly on the user's computer, as a stand-alone software package, partly on the user's computer and partly on a remote computer or entirely on the remote computer or server. In the latter scenario, the remote computer may be connected to the user's computer through any type of network, including a local area network (“LAN”) or a wide area network (“WAN”), or the connection may be made to an external computer (for example, through the Internet using an Internet Service Provider).

[0023] Reference throughout this specification to “one embodiment,” “an embodiment,” or similar language means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment. Thus, appearances of the phrases “in one embodiment,” “in an embodiment,” and similar language throughout this specification may, but do not necessarily, all refer to the same embodiment, but mean “one or more but not all embodiments” unless expressly specified otherwise. The terms “including,” “comprising,” “having,” and variations thereof mean “including but not limited to,” unless expressly specified otherwise. An enumerated listing of items does not imply that any or all of the items are mutually exclusive, unless expressly specified otherwise. The terms “a,” “an,” and “the” also refer to “one or more” unless expressly specified otherwise.

[0024] Furthermore, the described features, structures, or characteristics of the embodiments may be combined in any suitable manner. In the following description, numerous specific details are provided, such as examples of programming, software modules, user selections, network transactions, database queries, database structures, hardware modules, hardware circuits, hardware chips, etc., to provide a thorough understanding of embodiments. One skilled in the relevant art will recognize, however, that embodiments may be practiced without one or more of the specific details, or with other methods, components, materials, and so forth. In other instances, well-known structures, materials, or operations are not shown or described in detail to avoid obscuring aspects of an embodiment. [0025] Aspects of the embodiments are described below with reference to schematic flowchart diagrams and/or schematic block diagrams of methods, apparatuses, systems, and program products according to embodiments. It will be understood that each block of the schematic flowchart diagrams and/or schematic block diagrams, and combinations of blocks in the schematic flowchart diagrams and/or schematic block diagrams, can be implemented by code. The code may be provided to a processor of a general purpose computer, special purpose computer, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions/acts specified in the schematic flowchart diagrams and/or schematic block diagrams block or blocks.

[0026] The code may also be stored in a storage device that can direct a computer, other programmable data processing apparatus, or other devices to function in a particular manner, such that the instructions stored in the storage device produce an article of manufacture including instructions which implement the function/act specified in the schematic flowchart diagrams and/or schematic block diagrams block or blocks.

[0027] The code may also be loaded onto a computer, other programmable data processing apparatus, or other devices to cause a series of operational steps to be performed on the computer, other programmable apparatus or other devices to produce a computer implemented process such that the code which execute on the computer or other programmable apparatus provide processes for implementing the functions/acts specified in the flowchart and/or block diagram block or blocks.

[0028] The schematic flowchart diagrams and/or schematic block diagrams in the Figures illustrate the architecture, functionality, and operation of possible implementations of apparatuses, systems, methods and program products according to various embodiments. In this regard, each block in the schematic flowchart diagrams and/or schematic block diagrams may represent a module, segment, or portion of code, which includes one or more executable instructions of the code for implementing the specified logical function(s).

[0029] It should also be noted that, in some alternative implementations, the functions noted in the block may occur out of the order noted in the Figures. For example, two blocks shown in succession may, in fact, be executed substantially concurrently, or the blocks may sometimes be executed in the reverse order, depending upon the functionality involved. Other steps and methods may be conceived that are equivalent in function, logic, or effect to one or more blocks, or portions thereof, of the illustrated Figures. [0030] Although various arrow types and line types may be employed in the flowchart and/or block diagrams, they are understood not to limit the scope of the corresponding embodiments. Indeed, some arrows or other connectors may be used to indicate only the logical flow of the depicted embodiment. For instance, an arrow may indicate a waiting or monitoring period of unspecified duration between enumerated steps of the depicted embodiment. It will also be noted that each block of the block diagrams and/or flowchart diagrams, and combinations of blocks in the block diagrams and/or flowchart diagrams, can be implemented by special purpose hardware-based systems that perform the specified functions or acts, or combinations of special purpose hardware and code.

[0031] The description of elements in each figure may refer to elements of proceeding figures. Like numbers refer to like elements in all figures, including alternate embodiments of like elements.

[0032] Figure 1 depicts an embodiment of a wireless communication system 100 for repeated feedback transmission. In one embodiment, the wireless communication system 100 includes remote units 102 and network units 104. Even though a specific number of remote units 102 and network units 104 are depicted in Figure 1, one of skill in the art will recognize that any number of remote units 102 and network units 104 may be included in the wireless communication system 100.

[0033] In one embodiment, the remote units 102 may include computing devices, such as desktop computers, laptop computers, personal digital assistants (“PDAs”), tablet computers, smart phones, smart televisions (e.g., televisions connected to the Internet), set-top boxes, game consoles, security systems (including security cameras), vehicle on-board computers, network devices (e.g., routers, switches, modems), aerial vehicles, drones, or the like. In some embodiments, the remote units 102 include wearable devices, such as smart watches, fitness bands, optical head-mounted displays, or the like. Moreover, the remote units 102 may be referred to as subscriber units, mobiles, mobile stations, users, terminals, mobile terminals, fixed terminals, subscriber stations, user equipment (“UE”), user terminals, a device, or by other terminology used in the art. The remote units 102 may communicate directly with one or more of the network units 104 via UL communication signals. In certain embodiments, the remote units 102 may communicate directly with other remote units 102 via sidelink communication.

[0034] The network units 104 may be distributed over a geographic region. In certain embodiments, a network unit 104 may also be referred to and/or may include one or more of an access point, an access terminal, a base, a base station, a Node-B, an evolved node-B (“eNB”), a 5G node-B (“gNB”), a Home Node-B, a relay node, a device, a core network, an aerial server, a radio access node, an access point (“AP”), new radio (“NR”), a network entity, an access and mobility management function (“AMF”), a unified data management (“UDM”), a unified data repository (“UDR”), a UDM/UDR, a policy control function (“PCF”), a radio access network (“RAN”), a network slice selection function (“NSSF”), an operations, administration, and management (“OAM”), a session management function (“SMF”), a user plane function (“UPF”), an application function, an authentication server function (“AUSF”), security anchor functionality (“SEAF”), trusted non-3GPP gateway function (“TNGF”), or by any other terminology used in the art. The network units 104 are generally part of a radio access network that includes one or more controllers communicably coupled to one or more corresponding network units 104. The radio access network is generally communicably coupled to one or more core networks, which may be coupled to other networks, like the Internet and public switched telephone networks, among other networks. These and other elements of radio access and core networks are not illustrated but are well known generally by those having ordinary skill in the art.

[0035] In one implementation, the wireless communication system 100 is compliant with NR protocols standardized in third generation partnership project (“3GPP”), wherein the network unit 104 transmits using an OFDM modulation scheme on the downlink (“DL”) and the remote units 102 transmit on the uplink (“UL”) using a single-carrier frequency division multiple access (“SC-FDMA”) scheme or an orthogonal frequency division multiplexing (“OFDM”) scheme. More generally, however, the wireless communication system 100 may implement some other open or proprietary communication protocol, for example, WiMAX, institute of electrical and electronics engineers (“IEEE”) 802.11 variants, global system for mobile communications (“GSM”), general packet radio service (“GPRS”), universal mobile telecommunications system (“UMTS”), long term evolution (“LTE”) variants, code division multiple access 2000 (“CDMA2000”), Bluetooth®, ZigBee, Sigfoxx, among other protocols. The present disclosure is not intended to be limited to the implementation of any particular wireless communication system architecture or protocol.

[0036] The network units 104 may serve a number of remote units 102 within a serving area, for example, a cell or a cell sector via a wireless communication link. The network units 104 transmit DL communication signals to serve the remote units 102 in the time, frequency, and/or spatial domain.

[0037] In various embodiments, a remote unit 102 may determine that a location of the user equipment is unknown to the user equipment. In some embodiments, the remote unit 102 may attempt to decode a transport block transmitted on a physical sidelink shared channel. In various embodiments, the remote unit 102 may, in response to unsuccessfully decoding the transport block transmitted on the physical sidelink shared channel, transmit a negative acknowledgement feedback until a threshold is reached. Accordingly, the remote unit 102 may be used for repeated feedback transmission.

[0038] Figure 2 depicts one embodiment of an apparatus 200 that may be used for repeated feedback transmission. The apparatus 200 includes one embodiment of the remote unit 102. Furthermore, the remote unit 102 may include a processor 202, a memory 204, an input device 206, a display 208, a transmitter 210, and a receiver 212. In some embodiments, the input device 206 and the display 208 are combined into a single device, such as a touchscreen. In certain embodiments, the remote unit 102 may not include any input device 206 and/or display 208. In various embodiments, the remote unit 102 may include one or more of the processor 202, the memory 204, the transmitter 210, and the receiver 212, and may not include the input device 206 and/or the display 208.

[0039] The processor 202, in one embodiment, may include any known controller capable of executing computer-readable instructions and/or capable of performing logical operations. For example, the processor 202 may be a microcontroller, a microprocessor, a central processing unit (“CPU”), a graphics processing unit (“GPU”), an auxiliary processing unit, a field programmable gate array (“FPGA”), or similar programmable controller. In some embodiments, the processor 202 executes instructions stored in the memory 204 to perform the methods and routines described herein. The processor 202 is communicatively coupled to the memory 204, the input device 206, the display 208, the transmitter 210, and the receiver 212.

[0040] The memory 204, in one embodiment, is a computer readable storage medium. In some embodiments, the memory 204 includes volatile computer storage media. For example, the memory 204 may include a RAM, including dynamic RAM (“DRAM”), synchronous dynamic RAM (“SDRAM”), and/or static RAM (“SRAM”). In some embodiments, the memory 204 includes non-volatile computer storage media. For example, the memory 204 may include a hard disk drive, a flash memory, or any other suitable non-volatile computer storage device. In some embodiments, the memory 204 includes both volatile and non-volatile computer storage media. In some embodiments, the memory 204 also stores program code and related data, such as an operating system or other controller algorithms operating on the remote unit 102.

[0041] The input device 206, in one embodiment, may include any known computer input device including a touch panel, a button, a keyboard, a stylus, a microphone, or the like. In some embodiments, the input device 206 may be integrated with the display 208, for example, as a touchscreen or similar touch-sensitive display. In some embodiments, the input device 206 includes a touchscreen such that text may be input using a virtual keyboard displayed on the touchscreen and/or by handwriting on the touchscreen. In some embodiments, the input device 206 includes two or more different devices, such as a keyboard and a touch panel.

[0042] The display 208, in one embodiment, may include any known electronically controllable display or display device. The display 208 may be designed to output visual, audible, and/or haptic signals. In some embodiments, the display 208 includes an electronic display capable of outputting visual data to a user. For example, the display 208 may include, but is not limited to, a liquid crystal display (“LCD”), a light emitting diode (“LED”) display, an organic light emitting diode (“OLED”) display, a projector, or similar display device capable of outputting images, text, or the like to a user. As another, non-limiting, example, the display 208 may include a wearable display such as a smart watch, smart glasses, a heads-up display, or the like. Further, the display 208 may be a component of a smart phone, a personal digital assistant, a television, a table computer, a notebook (laptop) computer, a personal computer, a vehicle dashboard, or the like.

[0043] In certain embodiments, the display 208 includes one or more speakers for producing sound. For example, the display 208 may produce an audible alert or notification (e.g., a beep or chime). In some embodiments, the display 208 includes one or more haptic devices for producing vibrations, motion, or other haptic feedback. In some embodiments, all or portions of the display 208 may be integrated with the input device 206. For example, the input device 206 and display 208 may form a touchscreen or similar touch-sensitive display. In other embodiments, the display 208 may be located near the input device 206.

[0044] In certain embodiment, the processor 202 determines that a location of the user equipment is unknown to the user equipment; and attempts to decode a transport block transmitted on a physical sidelink shared channel. In various embodiments, the transmitter 210, in response to unsuccessfully decoding the transport block transmitted on the physical sidelink shared channel, transmits a negative acknowledgement feedback until a threshold is reached.

[0045] Although only one transmitter 210 and one receiver 212 are illustrated, the remote unit 102 may have any suitable number of transmitters 210 and receivers 212. The transmitter 210 and the receiver 212 may be any suitable type of transmitters and receivers. In one embodiment, the transmitter 210 and the receiver 212 may be part of a transceiver.

[0046] Figure 3 depicts one embodiment of an apparatus 300 that may be used for repeated feedback transmission. The apparatus 300 includes one embodiment of the network unit 104. Furthermore, the network unit 104 may include a processor 302, a memory 304, an input device 306, a display 308, a transmitter 310, and a receiver 312. As may be appreciated, the processor 302, the memory 304, the input device 306, the display 308, the transmitter 310, and the receiver 312 may be substantially similar to the processor 202, the memory 204, the input device 206, the display 208, the transmitter 210, and the receiver 212 of the remote unit 102, respectively.

[0047] In some embodiments, a number of non-acknowledgement or negative acknowledgement (“NACK”) feedbacks may be limited if a receiver (“RX”) location is not available. In various embodiments, a priority mechanism may be used so that NACK is only sent if a corresponding priority (e.g., included in sidelink control information (“SCI”)) is higher than (e.g., lower in numeric value) a threshold.

[0048] In certain embodiments, to limit a number of NACK feedbacks if a receiver user equipment (“UE”) does not have access to its location, the UE, upon not decoding a physical sidelink shared channel (“PSSCH”) successfully, transmits a limited number of NACK feedbacks for a transport block (“TB”). The limited number (e.g., a new threshold) may be less than or equal to a threshold (e.g., max-HARQ-ReTx threshold) and may be configured, preconfigured, or specified. If the UE fails to decode the PSSCH after exceeding the limited number, the UE may not provide additional NACK feedback for the same TB. As may be appreciated, acknowledgement (“ACK”) feedback may be provided anytime that PSSCH is successfully decoded. In one example, a maximum number of NACK feedback if a UE’s location is unavailable may be capped at a fixed value such as “1.” In some embodiments, a new threshold (or a capped value) may be set in proportion to and depending on a speed of a UE (e.g., relative or absolute), a direction of travel of the UE, and so forth.

[0049] Figure 4 is a diagram 400 illustrating one embodiment of vehicle directional travel. As illustrated, vehicle A 402 and vehicle B 404 travel in the same direction, vehicle C 406 and vehicle D 408 travel in the same direction. Furthermore, vehicle A 402 and vehicle C 406 travel in opposite directions, and vehicle B 404 and vehicle D 408 travel in opposite directions.

[0050] Figure 5 is a diagram illustrating one embodiment of a table 500 indicating capped values for providing NACK feedback corresponding to relative speeds. Moreover, Figure 6 is a diagram illustrating one embodiment of a table 600 indicating capped values for providing NACK feedback corresponding to absolute speeds. Specifically, Figure 6 shows example values for if a direction of travel is not available. In various embodiments, the direction of travel may be available.

[0051] In various embodiments, a vehicle provides HARQ feedback (e.g., ACK or NACK) as it would if its location is available until sometime (e.g., controlled using a time threshold and/or timer) after it determines that it no longer has access to its geographical location and/or position. This may be due to the fact that a highly mobile UE may not travel much in a short time instance of 100 ms or so (e.g., less than 10 meters if a relative velocity with the transmitter is as high as 360 kilometers per hour (“KMPH”)). A small distance travelled in a short time may be a fraction of a minimum communication range (“MCR”) that could range between 50 m to 1000 m. The time threshold and/or timer may be longer if a relative velocity is as low as 0-10 KMPH (e.g., if a transmitter UE and a receiver UE are part of a platoon moving in the same direction). In certain embodiments, a relative speed and/or direction of travel may be used to determine a length of a timer. In some embodiments, if a relative speed with a transmitter UE is not available, a receiver UE may use a different timer (e.g., value) based on its own absolute speed and direction of travel. In various embodiments, direction of travel may be determined with respect to a transmitter UE (e.g., if a receiver UE is moving in the same direction as the transmitter UE then direction is the “same,” if the receiver UE is moving in the opposite direction as the transmitter UE then direction is “opposite”). As may be appreciated, timer values may be longer for the same direction travel and shorter for opposite direction travel.

[0052] Figure 7 is a diagram illustrating one embodiment of a table 700 indicating timer values for providing NACK feedback corresponding to relative speeds. Moreover, Figure 8 is a diagram illustrating one embodiment of a table 800 indicating timer values for providing NACK feedback corresponding to absolute speeds.

[0053] Figure 8 shows example values for a case when relative speed/ direction of travel are not available. There could be another table for the case when the direction of travel indeed is available. As would be appreciated, the timer values will be longer for the same direction travel and shorter for the opposite direction travel.

[0054] In certain embodiments, a receiver (“RX”) UE (e.g., not having access to its own location) may randomly decide if a NACK should be sent based on a persistence check value that may be configured, preconfigured, or specified. In such embodiments, the RX UE may use a decimal value between 0.0 and 1.0 and compare this decimal value to the persistence check value. In one example, a NACK transmission may only be made if the decimal value is ‘less than’ (or in another example ‘greater than’) the configured, preconfigured, or specified persistence check value.

[0055] In various embodiments, an RX UE sends a NACK only if reference signal received power (“RSRP”) (e.g., pathloss) of a transmitter (“TX”) UE is above (or less than) a threshold, otherwise feedback is not sent. In such embodiments, RX UEs that are far from the TX UE do not provide NACK feedback.

[0056] In some embodiments, a receiver UE always sends hybrid automatic repeat request (“HARQ”) feedback if option 2 based HARQ feedback (“HF”) is used, otherwise (e.g., for option 1 based feedback (“FB”)) the receiver UE either does not provide NACK feedback or the receiver UE provides NACK feedback (e.g., based on an RSRP threshold or persistence check, or restricts a number of NACK feedback up to a maximum number of feedbacks).

[0057] Figure 9 is a flow chart diagram illustrating one embodiment of a method 900 for repeated feedback transmission. In some embodiments, the method 900 is performed by an apparatus, such as the remote unit 102. In certain embodiments, the method 900 may be performed by a processor executing program code, for example, a microcontroller, a microprocessor, a CPU, a GPU, an auxiliary processing unit, a FPGA, or the like.

[0058] In various embodiments, the method 900 includes determining 902 that a location of the user equipment is unknown to the user equipment. In some embodiments, the method 900 includes attempting 904 to decode a transport block transmitted on a physical sidelink shared channel. In various embodiments, the method 900 includes, in response to unsuccessfully decoding the transport block transmitted on the physical sidelink shared channel, transmitting 906 a negative acknowledgement feedback until a threshold is reached.

[0059] In certain embodiments, the threshold comprises a threshold number of times. In some embodiments, the threshold is less than or equal to a max-HARQ-ReTx threshold. In various embodiments, the threshold is preconfigured or specified. In one embodiment, the threshold is based on a speed of the user equipment.

[0060] In certain embodiments, the threshold is proportional to the speed of the user equipment. In some embodiments, the threshold is directly related to the speed of the user equipment. In various embodiments, the method 900 further comprises, in response to unsuccessfully decoding the transport block transmitted on the physical sidelink shared channel after transmitting the negative acknowledgement feedback until the threshold is reached, inhibiting transmission of the negative acknowledgement feedback for the transport block.

[0061] In one embodiment, the method 900 further comprises, in response to successfully decoding the transport block transmitted on the physical sidelink shared channel, transmitting a positive acknowledgement feedback. In certain embodiments, the threshold comprises a time threshold. In some embodiments, the threshold comprises a persistence check value.

[0062] In one embodiment, a method comprises: determining, at a user equipment, that a location of the user equipment is unknown to the user equipment; attempting to decode a transport block transmitted on a physical sidelink shared channel; and in response to unsuccessfully decoding the transport block transmitted on the physical sidelink shared channel, transmitting a negative acknowledgement feedback until a threshold is reached.

[0063] In certain embodiments, the threshold comprises a threshold number of times. [0064] In some embodiments, the threshold is less than or equal to a max-HARQ-ReTx threshold.

[0065] In various embodiments, the threshold is preconfigured or specified.

[0066] In one embodiment, the threshold is based on a speed of the user equipment. [0067] In certain embodiments, the threshold is proportional to the speed of the user equipment.

[0068] In some embodiments, the threshold is directly related to the speed of the user equipment.

[0069] In various embodiments, the method further comprises, in response to unsuccessfully decoding the transport block transmitted on the physical sidelink shared channel after transmitting the negative acknowledgement feedback until the threshold is reached, inhibiting transmission of the negative acknowledgement feedback for the transport block.

[0070] In one embodiment, the method further comprises, in response to successfully decoding the transport block transmitted on the physical sidelink shared channel, transmitting a positive acknowledgement feedback.

[0071] In certain embodiments, the threshold comprises a time threshold.

[0072] In some embodiments, the threshold comprises a persistence check value.

[0073] In one embodiment, an apparatus comprises a user equipment. The apparatus further comprises: a processor that: determines that a location of the user equipment is unknown to the user equipment; and attempts to decode a transport block transmitted on a physical sidelink shared channel; and a transmitter that, in response to unsuccessfully decoding the transport block transmitted on the physical sidelink shared channel, transmits a negative acknowledgement feedback until a threshold is reached.

[0074] In certain embodiments, the threshold comprises a threshold number of times. [0075] In some embodiments, the threshold is less than or equal to a max-HARQ-ReTx threshold.

[0076] In various embodiments, the threshold is preconfigured or specified.

[0077] In one embodiment, the threshold is based on a speed of the user equipment.

[0078] In certain embodiments, the threshold is proportional to the speed of the user equipment.

[0079] In some embodiments, the threshold is directly related to the speed of the user equipment.

[0080] In various embodiments, the processor, in response to unsuccessfully decoding the transport block transmitted on the physical sidelink shared channel after transmitting the negative acknowledgement feedback until the threshold is reached, inhibits transmission of the negative acknowledgement feedback for the transport block.

[0081] In one embodiment, the transmitter, in response to successfully decoding the transport block transmitted on the physical sidelink shared channel, transmits a positive acknowledgement feedback.

[0082] In certain embodiments, the threshold comprises a time threshold.

[0083] In some embodiments, the threshold comprises a persistence check value.

[0084] Embodiments may be practiced in other specific forms. The described embodiments are to be considered in all respects only as illustrative and not restrictive. The scope of the invention is, therefore, indicated by the appended claims rather than by the foregoing description. All changes which come within the meaning and range of equivalency of the claims are to be embraced within their scope.

Claims

1 A method comprising: determining, at a user equipment, that a location of the user equipment is unknown to the user equipment; attempting to decode a transport block transmitted on a physical sidelink shared channel; and in response to unsuccessfully decoding the transport block transmitted on the physical sidelink shared channel, transmitting a negative acknowledgement feedback until a threshold is reached.

2 The method of claim 1, wherein the threshold comprises a threshold number of times.

3. The method of claim 1, wherein the threshold is less than or equal to a max-HARQ-ReTx threshold.

4. The method of claim 1, wherein the threshold is preconfigured or specified.

5. The method of claim 1, wherein the threshold is based on a speed of the user equipment.

6 The method of claim 5, wherein the threshold is proportional to the speed of the user equipment.

7. The method of claim 5, wherein the threshold is directly related to the speed of the user equipment.

8 The method of claim 1, further comprising, in response to unsuccessfully decoding the transport block transmitted on the physical sidelink shared channel after transmitting the negative acknowledgement feedback until the threshold is reached, inhibiting transmission of the negative acknowledgement feedback for the transport block.

9. The method of claim 1, further comprising, in response to successfully decoding the transport block transmitted on the physical sidelink shared channel, transmitting a positive acknowledgement feedback.

10 The method of claim 1, wherein the threshold comprises a time threshold.

11 The method of claim 1, wherein the threshold comprises a persistence check value.

12. An apparatus comprising a user equipment, the apparatus further comprising: a processor that: determines that a location of the user equipment is unknown to the user equipment; and attempts to decode a transport block transmitted on a physical sidelink shared channel; and a transmitter that, in response to unsuccessfully decoding the transport block transmitted on the physical sidelink shared channel, transmits a negative acknowledgement feedback until a threshold is reached.

13. The apparatus of claim 12, wherein the threshold comprises a threshold number of times.

14. The apparatus of claim 12, wherein the threshold is less than or equal to a max-HARQ-

ReTx threshold.

15. The apparatus of claim 12, wherein the threshold is preconfigured or specified.

16. The apparatus of claim 12, wherein the threshold is based on a speed of the user equipment.

17. The apparatus of claim 16, wherein the threshold is proportional to the speed of the user equipment.

18. The apparatus of claim 16, wherein the threshold is directly related to the speed of the user equipment.

19. The apparatus of claim 12, wherein the processor, in response to unsuccessfully decoding the transport block transmitted on the physical sidelink shared channel after transmitting the negative acknowledgement feedback until the threshold is reached, inhibits transmission of the negative acknowledgement feedback for the transport block.

20. The apparatus of claim 12, wherein the transmitter, in response to successfully decoding the transport block transmitted on the physical sidelink shared channel, transmits a positive acknowledgement feedback.

21. The apparatus of claim 12, wherein the threshold comprises a time threshold.

22. The apparatus of claim 12, wherein the threshold comprises a persistence check value.