Air-to-ground communication scheduling

Abstract

Aspects of the present disclosure generally relate to wireless communication. In some aspects, a base station associated with a cell of a time division duplex communication system may determine a guard interval less than a maximum time delay for air-to-ground communication at least in part based on a radius of the cell; and transmit a scheduling configuration identifying the guard interval to a user equipment. Many other aspects are provided.

Description

Technical Field

[0001] Aspects of the present disclosure generally relate to wireless communications and techniques and apparatuses for air-to-ground (ATG) communication scheduling. Background Art

[0002] Wireless communication systems are widely deployed to provide various telecommunication services such as telephony, video, data, messaging, and broadcasting. A typical wireless communication system may employ a multiple access technology capable of supporting communication with multiple user equipments (UEs) by sharing available system resources (e.g., bandwidth, transmit power, etc.). 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, and long term evolution (LTE). LTE / LTE-Advanced is an enhanced set of the universal mobile telecommunications system (UMTS) mobile standards released by the 3rd Generation Partnership Project (3GPP).

[0003] A wireless communication network may include a number of base stations (BSs) capable of supporting communication for a number of user equipments (UEs). The user equipment (UE) may communicate with the base station (BS) via a downlink and an uplink. The downlink (or forward link) refers to the communication link from the BS to the UE, and the uplink (or reverse link) refers to the communication link from the UE to the BS. As will be described in more detail herein, the BS may be referred to as a Node B, gNB, access point (AP), radio head, transmit receive point (TRP), new radio (NR) BS, 5G Node B, etc.

[0004] The above multiple access technologies have been adopted in various telecommunication standards to provide a common protocol that enables different user equipments to communicate at the urban, national, regional, and even global levels. New radio (NR), also referred to as 5G, is an enhanced set of the LTE mobile standards released by the 3rd Generation Partnership Project (3GPP). NR aims to improve spectral efficiency, reduce costs, improve services, utilize new spectrums, and better integrate with other open standards by using orthogonal frequency division multiplexing (OFDM) with cyclic prefix (CP) (CP-OFDM) on the downlink (DL), CP-OFDM and / or SC-FDM (e.g., also referred to as discrete Fourier transform spread OFDM (DFT-s-OFDM)) on the uplink (UL), and supporting beamforming, multiple input multiple output (MIMO) antenna technology, and carrier aggregation, so as to better support mobile broadband Internet access. However, with the increasing demand for mobile broadband access, there is a need for further improvement in LTE and NR technologies. Preferably, these improvements should be applicable to other multiple access technologies and telecommunication standards that employ these technologies. Summary of the Invention

[0005] In some aspects, a wireless communication method performed by a base station associated with a cell of a time division duplex (TDD) communication system may include: determining a guard interval less than a maximum time delay for ATG communication at least in part based on the radius of the cell; and transmitting to a UE a scheduling configuration identifying the guard interval.

[0006] In some aspects, a wireless communication method performed by a UE of a time division duplex (TDD) communication system may include receiving a scheduling configuration that at least in part is based on the radius of the cell in which the UE is located, identifying a guard interval less than a maximum time delay for ATG communication; and transmitting or receiving communication according to the scheduling configuration.

[0007] In some aspects, a base station for wireless communication associated with a cell of a time division duplex (TDD) communication system may include a memory and one or more processors operatively coupled to the memory. The memory and the one or more processors may be configured to determine a guard interval less than a maximum time delay for ATG communication at least in part based on the radius of the cell; and transmit to a UE a scheduling configuration identifying the guard interval.

[0008] In some aspects, a UE for wireless communication of a time division duplex (TDD) communication system may include a memory and one or more processors operatively coupled to the memory. The memory and the one or more processors may be configured to receive a scheduling configuration that at least in part is based on the radius of the cell in which the UE is located to identify a guard interval less than a maximum time delay for ATG communication; and transmit or receive communication according to the scheduling configuration.

[0009] In some aspects, a non-transitory computer-readable medium may store one or more instructions for wireless communication. When the one or more instructions are executed by one or more processors of a base station associated with a cell of a time division duplex (TDD) communication system, the one or more processors may be caused to: determine a guard interval less than a maximum time delay for ATG communication at least in part based on the radius of the cell; and transmit to a UE a scheduling configuration identifying the guard interval.

[0010] In some aspects, a non-transitory computer-readable medium may store one or more instructions for wireless communication. When the one or more instructions are executed by one or more processors of a UE of a time division duplex (TDD) communication system, the one or more processors may be caused to: receive a scheduling configuration that at least in part is based on the radius of the cell in which the UE is located to identify a guard interval less than a maximum time delay for ATG communication; and transmit or receive communication according to the scheduling configuration.

[0011] In some aspects, an apparatus for wireless communication associated with a cell of a time division duplex communication system may include components for determining a guard interval less than a maximum time delay for ATG communication based at least in part on the radius of the cell; and components for sending to a UE a scheduling configuration identifying the guard interval.

[0012] In some aspects, an apparatus for wireless communication in a time division duplex communication system may include: components for receiving a scheduling configuration that identifies, at least in part based on the radius of the cell in which the apparatus is located, a guard interval less than a maximum time delay for ATG communication; and components for sending or receiving communication according to the scheduling configuration.

[0013] Aspects generally include methods, apparatuses, systems, computer program products, non-transitory computer-readable media, user equipment, base stations, wireless communication devices, and / or processing systems substantially as described herein with reference to the figures and as illustrated in the figures and the specification.

[0014] The foregoing has outlined rather broadly the features and technical advantages of examples in accordance with the present disclosure so that the following detailed description may be better understood. Additional features and advantages will be described hereinafter. The disclosed concepts and specific examples 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 structures do not depart from the scope of the appended claims. When considered in conjunction with the accompanying drawings, the features of the concepts disclosed herein, their organization and method of operation, and related advantages will be better understood. Each of the figures is provided for the purpose of illustration and description and is not intended as a definition of the limits of the claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] To enable a more particular understanding of the foregoing features of the present disclosure, a more specific description may be obtained by reference to some of the aspects illustrated in the drawings. It should be noted, however, that the drawings illustrate only certain typical aspects of the present disclosure and are therefore not to be considered limiting of its scope, as the description may admit to other equally effective aspects. Like reference numerals in different drawings may identify the same or similar elements.

[0016] Figure 1 is a block diagram conceptually illustrating an example of a wireless communication network in accordance with various aspects of the present disclosure.

[0017] Figure 2 is a block diagram conceptually illustrating an example of a base station communicating with a UE in a wireless communication network in accordance with various aspects of the present disclosure.

[0018] Figure 3 is a block diagram conceptually illustrating an example of a frame structure in a wireless communication network in accordance with various aspects of the present disclosure.

[0019] Figure 4 is a block diagram conceptually showing an example time slot format with a normal cyclic prefix according to various aspects of the present disclosure.

[0020] Figures 5 - 7 is a diagram showing an example of ATG communication scheduling according to various aspects of the present disclosure.

[0021] Figure 8 is a diagram showing an example process, such as performed by a base station, according to various aspects of the present disclosure.

[0022] Figure 9 is a diagram showing an example process, such as performed by a UE, according to various aspects of the present disclosure. DETAILED DESCRIPTION

[0023] Various aspects of the present disclosure are described more fully hereinafter with reference to the accompanying drawings. However, the present disclosure may be embodied 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, those 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 in combination with any other aspect of the present disclosure. For example, a device may be implemented using any number of the aspects set forth herein or a method may be practiced. Additionally, the scope of the present disclosure is intended to cover such a device or method that uses other structures, functions, or a combination of structures and functions in addition to or different from 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.

[0024] Several aspects of a telecommunications system will now be presented with reference to various devices and techniques. These devices and techniques will be described in the following detailed description and illustrated in the drawings by various blocks, modules, components, circuits, steps, processes, algorithms, etc. (collectively referred to as "elements"). These elements may be implemented using hardware, software, or a combination thereof. Whether these elements are implemented as hardware or software depends on the particular application and design constraints imposed on the overall system.

[0025] It should be noted that although terms typically associated with 3G and / or 4G wireless technologies may be used herein to describe aspects, aspects of the present disclosure are applicable to other generation-based communication systems including NR technologies, such as 5G and later versions.

[0026] Figure 1FIG. is a diagram illustrating a wireless network 100 in which aspects of the present disclosure may be practiced. The wireless network 100 may be an LTE network or some other wireless network, such as a 5G or NR network. The wireless network 100 may include a number of BSs 110 (shown as BS110a, BS110b, BS110c, and BS110d) and other network entities. A BS is an entity that communicates with user equipment (UE) and may also be referred to as a base station, NR BS, Node B, gNB, 5G Node B (NB), access point, transmit receive point (TRP), etc. Each BS may provide communication coverage for a particular geographic area. In 3GPP, the term "cell" can refer to the coverage area of a BS and / or the BS subsystem serving that coverage area, depending on the context in which the term is used.

[0027] 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., with a radius of several kilometers) and may allow unrestricted access by UEs having a service subscription. A pico cell may cover a relatively small geographic area and may allow unrestricted access by UEs having a service subscription. A femto cell may cover a relatively small geographic area (e.g., a home) and may allow restricted access by UEs associated 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 Figure 1 the example shown, BS110a may be a macro BS for macro cell 102a, BS110b may be a pico BS for pico cell 102b, and BS110c may be a femto BS for femto cell 102c. A BS may support one or more (e.g., three) cells. The terms "eNB," "base station," "NR BS," "gNB," "TRP," "AP," "Node B," "5G NB," and "cell" may be used interchangeably herein.

[0028] In some aspects, a cell may not necessarily be fixed, and the geographic area of a cell may move according to the location of a mobile BS. In some aspects, BSs may be interconnected with each other and / or with one or more BSs or network nodes (not shown) in the wireless network 100 via various types of backhaul interfaces, such as direct physical connections, virtual networks, and / or analogs using any suitable transport network.

[0029] The wireless network 100 may also include relay stations. A relay station is an entity that can receive the transmission of data from an upstream station (e.g., a BS or a UE) and forward the transmission of data to a downstream station (e.g., a UE or a BS). A relay station can also be a UE that can relay transmissions for other UEs. In Figure 1 the example shown in, relay station 110d can communicate with macro BS 110a and UE 120d to facilitate communication between BS 110a and UE 120d. A relay station can also be referred to as a relay BS, a relay base station, a relay, etc.

[0030] The wireless network 100 can be a heterogeneous network that includes different types of BSs, such as macro BSs, pico BSs, femto BSs, relay BSs, etc. These different types of BSs can have different transmit power levels, different coverage areas, and different impacts on interference in the wireless network 100. For example, a macro BS can have a high transmit power level (e.g., 5 to 40 watts), while pico BSs, femto BSs, and relay BSs can have lower transmit power levels (e.g., 0.1 to 2 watts).

[0031] The network controller 130 can be coupled to a set of BSs and can provide coordination and control for these BSs. The network controller 130 can communicate with the BSs via a backhaul. The BSs can also communicate with each other directly or indirectly via a wireless or wired backhaul, e.g.,

[0032] UEs 120 (e.g., 120a, 120b, 120c) can be dispersed throughout the wireless network 100, and each UE can be fixed or mobile. A UE can also be referred to as an access terminal, a terminal, a mobile station, a subscriber unit, a station, etc. A UE can 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 computer, a camera, a gaming device, a netbook, a smartbook, a superbook, a medical device or equipment, a biometric sensor / device, a wearable device (smart watch, smart clothing, smart glasses, smart wristband, smart jewelry (e.g., smart ring, smart bracelet)), an entertainment device (e.g., a music or video device or a satellite radio), a vehicle component or sensor, a smart meter / sensor, an industrial manufacturing equipment, a global positioning system device, or any other suitable device configured to communicate via a wireless or wired medium.

[0033] Some UEs can 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, etc., which can communicate with a base station, another device (e.g., a remote device), or some other entity. For example, a wireless node can provide connectivity to or from a network (e.g., a wide area network such as the Internet or a cellular network) via a wired or wireless communication link. Some UEs can be considered as Internet of Things (IoT) devices, and / or can be implemented as NarrowBand IoT (NB-IoT) devices. Some UEs can be regarded as Customer Premises Equipment (CPE). The UE 120 can be included within a housing that houses components of the UE 120, such as processor components, memory components, etc.

[0034] Generally, any number of wireless networks can be deployed in a given geographical area. Each wireless network can support a specific RAT and can operate on one or more frequencies. The RAT can also be referred to as a radio technology, an air interface, etc. The frequency can also be called a carrier, a channel, etc. Each frequency can support a single RAT in a given geographical area to avoid interference between wireless networks of different RATs. In some cases, an NR or 5G RAT network can be deployed.

[0035] In some aspects, two or more UEs 120 (e.g., shown as UE 120a and UE 120e) can communicate directly using one or more sidelink channels (e.g., communicate with each other without using the base station 110 as an intermediary). For example, the UE 120 can communicate using peer-to-peer (P2P) communication, device-to-device (D2D) communication, vehicle-to-everything (V2X) protocols (e.g., which can include vehicle-to-vehicle (V2V) protocols, vehicle-to-infrastructure (V2I) protocols, etc.), a mesh network, etc. In such cases, the UE 120 can perform scheduling operations, resource selection operations, and / or other operations described elsewhere herein as being performed by the base station 110.

[0036] As described above, provide Figure 1 as an example. Other examples may be different from the examples described with respect to Figure 1 which.

[0037] Figure 2 A block diagram of a design 200 of the base station 110 and the UE 120 is shown, which can be one of the base stations and one of the UEs in Figure 1 which. The base station 110 can be equipped with T antennas 234a to 234t, and the UE 120 can be equipped with R antennas 252a to 252r, where generally T≥1 and R≥1.

[0038] At the base station 110, a transmit processor 220 may receive data for one or more UEs from a data source 212, select one or more modulation and coding schemes (MCSs) for each UE at least in part based on channel quality indicators (CQIs) received from the UEs, process (e.g., encode and modulate) the data for each UE at least in part based on the MCSs selected for the UEs, and provide data symbols for all UEs. The transmit processor 220 may also process system information (e.g., for semi-static resource partitioning information (SRPI), etc.) and control information (e.g., CQI requests, grants, upper layer signaling, etc.) and provide overhead symbols and control symbols. The transmit processor 220 may also generate reference symbols for reference signals (e.g., cell-specific reference signals (CRSs)) and synchronization signals (e.g., primary synchronization signal (PSS) and secondary synchronization signal (SSS)). If applicable, a transmit (TX) multiple-input multiple-output (MIMO) processor 230 may perform spatial processing (e.g., precoding) on the data symbols, control symbols, overhead symbols, and / or reference symbols and may provide T output symbol streams to T modulators (MODs) 232a through 232t. Each modulator 232 may process its respective output symbol stream (e.g., for OFDM, etc.) to obtain an output sample stream. Each modulator 232 may further process (e.g., convert to analog, amplify, filter, and up-convert) the output sample stream to obtain a downlink signal. The T downlink signals from modulators 232a through 232t may be transmitted via T antennas 234a through 234t, respectively. In accordance with various aspects described in more detail below, position coding can be utilized to generate synchronization signals to convey additional information.

[0039] At the UE 120, antennas 252a through 252r may receive downlink signals from the base station 110 and / or other base stations and may provide the received signals to demodulators (DEMODs) 254a through 254r, respectively. Each demodulator 254 may condition (e.g., filter, amplify, down-convert, and digitize) the received signal to obtain input samples. Each demodulator 254 may further process the input samples (e.g., for OFDM, etc.) 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 the UE 120 to a data sink 260, and provide decoded control information and system information to a controller / processor 280. A channel processor may determine a reference signal received power (RSRP), a received signal strength indicator (RSSI), a reference signal received quality (RSRQ), a channel quality indicator (CQI), etc. In some aspects, one or more components of the UE 120 may be included in a housing.

[0040] On the uplink, at the UE 120, the transmitting processor 264 may receive and process data from the data source 262 and control information from the controller / processor 280 (e.g., for reports including RSRP, RSSI, RSRQ, CQI, etc.). The transmitting processor 264 may also generate reference symbols for one or more reference signals. If applicable, the symbols from the transmitting processor 264 may be precoded by the TX MIMO processor 266, further processed by the modulators 254a to 254r (e.g., for DFT-s-OFDM, CP-OFDM, etc.), and transmitted to the base station 110. At the base station 110, the uplink signals from the UE 120 and other UEs may be received by the antenna 234, processed by the demodulator 232, detected by the MIMO detector 236 if applicable, and further processed by the receiving processor 238 to obtain the decoded data and control information transmitted by the UE 120. The receiving processor 238 may provide the decoded data to the data sink 239 and the decoded control information to the controller / processor 240. The base station 110 may include a communication unit 244 and communicate with the network controller 130 via the communication unit 244. The network controller 130 may include a communication unit 294, a controller / processor 290, and a memory 292.

[0041] The controller / processor 240 of the base station 110, the controller / processor 280 of the UE 120, and / or Figure 2 any other components of may perform one or more techniques associated with ATG communication scheduling, as described in more detail elsewhere herein. For example, the controller / processor 240 of the base station 110, the controller / processor 280 of the UE 120, and / or Figure 2 any other components of may execute or direct, for example Figure 8 the process 800 of, Figure 9 the process 900 of, and / or the operations of other processes as described herein. The memories 242 and 282 may store data and program codes for the base station 110 and the UE 120, respectively. In some aspects, the memory 242 and / or the memory 282 may include a non-transitory computer-readable medium storing one or more instructions for wireless communication. For example, when executed by one or more processors of the base station 110 and / or the UE 120, the one or more instructions may execute or direct, for example Figure 8 the process 800 of, Figure 9 the process 900 of, and / or the operations of other processes as described herein. The scheduler 246 may schedule the UE for data transmission on the downlink and / or the uplink.

[0042] In some aspects, the UE 120 may include components for receiving a scheduling configuration that identifies a guard interval less than a maximum time delay for ATG communication based at least in part on a radius of a cell, components for transmitting or receiving communication according to the scheduling configuration, etc. In some aspects, such components may include one or more components of the UE 120 described in conjunction with Figure 2 , such as the controller / processor 280, transmit processor 264, TX MIMO processor 266, MOD 254, antenna 252, DEMOD 254, MIMO detector 256, receive processor 258, etc.

[0043] In some aspects, the base station 110 may include components for determining a guard interval less than a maximum time delay for ATG communication based at least in part on a radius of a cell, components for sending to the UE a scheduling configuration that identifies the guard interval, etc. In some aspects, such components may include one or more components of the base station 110 described in conjunction with Figure 2 , such as antenna 234, DEMOD 232, MIMO detector 236, receive processor 238, controller / processor 240, transmit processor 220, TX MIMO processor 230, MOD 232, antenna 234, etc.

[0044] As described above, provided Figure 2 as an example. Other examples may be different from the examples described with respect to Figure 2 .

[0045] Figure 3 FIG. shows an example frame structure 300 in a telecommunication system (e.g., NR). The transmission timeline for each of the downlink and uplink may be divided into units of radio frames (sometimes referred to as frames). Each radio frame may have a predetermined duration (e.g., 10 milliseconds (ms)) and may be divided into a set of Z (Z≥1) subframes (e.g., having indices from 0 to Z-1). Each subframe may have a predetermined duration (e.g., 1 ms) and may include a set of time slots (e.g., each subframe shows 2m time slots in Figure 3 , where m is a set of parameters for transmission, such as 0, 1, 2, 3, 4, etc.). Each time slot may include a set of L symbol periods. For example, each time slot may include fourteen symbol periods (e.g., as shown in Figure 3 ), seven symbol periods, or some other number of symbol periods. In the case where a subframe includes two time slots (e.g., when m = 1), the subframe may include 2L symbol periods, where the 2L symbol periods in each subframe may be assigned indices from 0 to 2L-1. In some aspects, the scheduling unit for FDD may be frame-based, subframe-based, time slot-based, symbol-based, etc.

[0046] Although some techniques are described herein in connection with frames, sub - frames, time slots, etc., these techniques can equally apply to other types of wireless communication structures that can be referred to using other terms in 5G NR other than "frame", "sub - frame", "time slot", etc. In some aspects, a wireless communication structure can refer to a periodic time - bounded communication unit defined by a wireless communication standard and / or protocol. Additionally or alternatively, configurations of wireless communication structures different from the configuration shown in Figure 3 can be used.

[0047] In certain telecommunications (e.g., NR), a base station can transmit synchronization signals. For example, a base station can transmit a primary synchronization signal (PSS), a secondary synchronization signal (SSS), etc. on the downlink for each cell supported by the base station. The PSS and SSS can be used by a UE for cell search and acquisition. For example, the PSS can be used by the UE to determine symbol timing, and the SSS can be used by the UE to determine the physical cell identifier and frame timing associated with the base station. The base station can also transmit a physical broadcast channel (PBCH). The PBCH can carry some system information, such as system information that supports initial access by the UE.

[0048] As described above, provided Figure 3 as an example. Other examples may be different from the examples described with respect to Figure 3 that.

[0049] Figure 4 An example time - slot format 410 with a normal cyclic prefix is shown. The available time - frequency resources can be divided into resource blocks. Each resource block can cover a set of sub - carriers in a time slot (e.g., 12 sub - carriers) and can include a number of resource elements. Each resource element can cover one sub - carrier in a symbol period (e.g., in time) and can be used to transmit one modulation symbol that can be a real - valued or complex - valued number.

[0050] In certain telecommunications systems (e.g., NR), an interleaving structure can be used for each of the downlink and uplink of FDD. For example, Q interleavings with indices from 0 to Q - 1 can be defined, where Q can be equal to 4, 6, 8, 10, or some other value. Each interleaving can include time slots spaced Q frames apart. In particular, interleaving q can include time slots q, q + Q, q + 2Q, etc., where q ∈ {0,...,Q – 1}.

[0051] A UE can be within the coverage of multiple BSs. One of these BSs can be selected to serve the UE. The serving BS can be selected at least in part based on various criteria such as received signal strength, received signal quality, path loss, etc. The received signal quality can be quantified by a signal-to-noise interference ratio (SNIR) or a reference signal received quality (RSRQ) or some other metric. The UE can operate in a significant interference scenario where the UE can observe high interference from one or more interfering BSs.

[0052] Although aspects of the examples described herein may be associated with NR or 5G technologies, aspects of the present disclosure may be applicable to other wireless communication systems. New Radio (NR) can refer to a radio configured to operate according to a new air interface (e.g., different from an air interface based on orthogonal frequency division multiple access (OFDMA)) or a fixed transport layer (e.g., different from Internet Protocol (IP)). In multiple aspects, NR can use OFDM with cyclic prefix (referred to herein as cyclic prefix OFDM or CP-OFDM) and / or SC-FDM on the uplink, can use CP-OFDM on the downlink, and includes support for half-duplex operation using time division duplex (TDD). In multiple aspects, NR can, for example, use OFDM with cyclic prefix (referred to herein as CP-OFDM) and / or discrete Fourier transform spread orthogonal frequency division multiplexing (DFT-s-OFDM) on the uplink, can use CP-OFDM on the downlink, and includes support for half-duplex operation using TDD. NR can include enhanced mobile broadband (eMBB) services for wide bandwidths (e.g., 80 megahertz (MHz) and above), millimeter wave (mmW) for high carrier frequencies (e.g., 60 gigahertz (GHz)), massive machine type communication (mMTC) for non-backward compatible MTC technologies, and / or mission critical for ultra-reliable low latency communication (URLLC) services.

[0053] In some aspects, a single component carrier bandwidth of 100 MHz can be supported. An NR resource block can span 12 subcarriers with a subcarrier bandwidth of 60 or 120 kilohertz (kHz) over a duration of 0.1 millisecond (ms). Each radio frame can include 40 time slots and can have a length of 10 ms. Thus, each time slot can have a length of 0.25 ms. Each time slot can indicate a link direction for data transmission (e.g., DL or UL), and the link direction for each time slot can be switched dynamically. Each time slot can include DL / UL data as well as DL / UL control data.

[0054] It can support beamforming and can dynamically configure the beam direction. It can also support MIMO transmission with precoding. The MIMO configuration in DL can support 8 transmit antennas for multi-layer DL transmission with up to 8 streams and up to 2 streams per UE. It can support multi-layer transmission with up to 2 streams per UE. It can support the aggregation of multiple cells with up to 8 serving cells. Alternatively, NR can support different air interfaces in addition to the OFDM-based interface. The NR network can include entities such as a central unit or a distributed unit.

[0055] As described above, provided Figure 4 as an example. Other examples may be different from the examples Figure 4 described.

[0056] Figure 5 is a diagram showing an example 500 of ATG communication scheduling according to various aspects of the present disclosure. As Figure 5 shown, the base station and the UE can perform ATG communication. In some aspects, the UE can receive a downlink transmission 510 from the base station according to a scheduling configuration provided by the base station and send an uplink transmission 520 to the base station. The scheduling configuration can identify a guard interval (which can also be referred to as a gap, a guard period, and / or various other suitable terms) 530. The guard interval 530 is a time separation that provides time for switching from the downlink transmission 510 (e.g., received by the UE) to the uplink transmission 520 (e.g., sent by the UE).

[0057] In the current ATG communication system, the guard interval 530 configured by the base station can be equal to or greater than the maximum round-trip delay in the cell including the base station. That is, the guard interval 530 can be equal to or greater than the round-trip delay between the UE at the edge of the cell and the base station (e.g., 2 × the propagation time from the UE at the edge of the cell to the base station). In the ATG communication system, the cell radius can be several hundred kilometers (e.g., 300 kilometers).

[0058] As Figure 5 shown, the base station can configure a guard interval 530 of four time slots to account for the maximum time delay (e.g., the maximum round-trip delay plus the round-trip downlink-uplink conversion delay) of the cell (e.g., 300 kilometers). However, as Figure 5As shown, the propagation delay 540 and the corresponding timing advance (TA) 550 between the UE and the base station may be relatively short (e.g., when the UE is not at the edge of the cell, such as 10 kilometers from the base station). For example, the TA 550 may use only one or more symbols of a time slot configured as the guard interval 530. Thus, the guard interval 530 configured to be equal to or greater than the maximum time delay in the cell (e.g., four time slots) reduces the throughput when the UE is not at the edge of the cell. Some of the techniques and apparatuses described herein use a guard interval less than the maximum time delay for ATG communication, thereby increasing the downlink and / or uplink transmission opportunities and improving the throughput.

[0059] As described above, provide Figure 5 As an example. Other examples may be different from the examples described with respect to Figure 5 those described.

[0060] Figure 6 is a diagram illustrating an example 600 of ATG communication scheduling according to various aspects of the present disclosure. As Figure 6 shown, the base station 110 and multiple UEs 120 may perform ATG communication. The base station 110 may be a land-based base station associated with a cell for ATG communication. For example, the cell may have a radius of one or several hundred kilometers (e.g., 100 - 500 kilometers). In some aspects, the base station 110 may communicate with the UEs 120 on a frequency band using time division duplex mode (e.g., NR band n79). The UEs 120 may be associated with non-terrestrial vehicles, such as airplanes, helicopters, airships, etc. In some aspects, the UEs 120 may be equipped with at least one Global Positioning System (GPS), which provides information identifying the location of the UEs 120.

[0061] As Figure 6As shown by reference numeral 610, the UE 120 can determine at least one of the location of the UE 120 and the timing difference (e.g., propagation delay or TA) for ATG communication with the base station 110. For example, the UE 120 can determine the location of the UE 120 at least in part based on data collected and provided by the GPS of the UE 120. Additionally, the UE 120 can determine the timing difference based on the location of the UE 120 and the location of the base station 110. The UE 120 can receive information identifying the location of the base station 110 from the base station 110 when entering the coverage area of the base station 110. In some aspects, the timing difference can be TA (e.g., round-trip delay (2×propagation delay) plus round-trip downlink to uplink conversion delay). The UE 120 can determine a TA with slot granularity (e.g., the TA is one or more slots) or symbol granularity (e.g., the TA is one or more symbols). In some aspects, the UE 120 can determine a TA with symbol granularity according to the random access procedure with the base station 110.

[0062] As shown by reference numeral 620, the UE 120 can send and the base station 110 can receive at least one of information identifying the timing difference (e.g., propagation delay or TA) for the UE and information identifying the location of the UE. For example, the UE 120 can send information identifying the timing difference or location when entering the cell associated with the base station 110. Additionally, when in the cell associated with the base station 110, the UE 120 can periodically send to the base station 110 at least one of information identifying the timing difference of the UE and information identifying the location of the UE. In some aspects, the base station 110 can receive corresponding information identifying the timing difference (e.g., propagation delay or TA) or location from multiple UEs 120 in the cell associated with the base station 110.

[0063] As shown by reference numeral 630, the base station 110 can determine a guard interval for ATG communication with multiple UEs 120. In some aspects, the base station 110 can determine a guard interval that is a fixed value at least in part based on the radius of the cell. For example, the base station 110 can determine at least in part based on the radius of the cell the maximum time delay for ATG communication in the cell. That is, the base station 110 can determine the maximum time delay between the UE 120 at the edge of the cell (e.g., according to the radius of the cell) and the base station 110. In some aspects, the base station 110 can be configured with information identifying the maximum time delay of the cell.

[0064] In some aspects, the maximum time delay may include a maximum round-trip delay for ATG communication in the cell that is at least partially based on the radius of the cell, and a round-trip downlink-uplink transition delay (e.g., downlink-to-uplink transition delay and uplink-to-downlink transition delay). The maximum round-trip delay may be the round-trip delay between the UE 120 at the edge of the cell (e.g., according to the radius of the cell) and the base station 110 (e.g., 2× the propagation delay from the UE 120 at the edge of the cell to the base station 110).

[0065] The base station 110 may determine a guard interval (e.g., a fixed value) that is less than the maximum time delay of the cell. In some aspects, the guard interval may be less than or equal to the minimum time delay for ATG communication in the cell. The minimum time delay may be at least partially based on the minimum height (e.g., historical minimum height) of the UE 120 when it is directly above the base station 110. Additionally or alternatively, the minimum time delay may be at least partially based on the most recent position (e.g., historical most recent position) of the UE 120 reported relative to the base station 110 or the minimum timing difference (e.g., historical minimum timing difference). In some aspects, the minimum time delay may include a minimum round-trip delay for ATG communication in the cell (e.g., at least partially based on the minimum height, most recent position, and / or minimum timing difference) and a round-trip downlink-uplink transition delay. In some aspects, the guard interval (e.g., a fixed value) may correspond to the round-trip downlink-uplink transition delay (e.g., downlink-to-uplink transition delay and uplink-to-downlink transition delay).

[0066] In some aspects, the base station 110 may determine the guard interval based on the maximum propagation delay in the cell. For example, the base station 110 may determine a guard interval that is greater than or equal to the time delay associated with the UE 120 that is furthest from the base station 110 (e.g., the furthest attached UE 120). In some aspects, the time delay associated with the furthest UE 120 may include a round-trip delay for the furthest UE 120 that is at least partially based on the distance of the furthest UE 120 from the base station 110, and a round-trip downlink-uplink transition delay (e.g., downlink-to-uplink transition delay and uplink-to-downlink transition delay).

[0067] The base station 110 can determine the farthest UE 120 based at least in part on at least one of the information identifying the location and the information identifying the timing difference for each UE 120 attached to the cell. For example, the base station 110 can determine the farthest UE 120 as the UE 120 reporting the largest timing difference (e.g., propagation delay or TA). In addition, the base station 110 can determine the distance of the farthest UE 120 based at least in part on at least one of the information identifying the location and the information identifying the timing difference reported by the farthest UE 120. For example, the base station 110 can determine the distance based on the timing difference (e.g., propagation delay or TA) assuming that the transmission from the UE will propagate at the speed of light.

[0068] As the UE 120 travels throughout the cell, the base station 110 can update the guard interval according to the updated time delay associated with the UE 120 that is farthest from the base station 110. For example, as the UE 120 travels closer to the base station 110, the base station 110 can determine a shortened guard interval according to the updated time delay associated with the UE 120 that is farthest from the base station 110. Similarly, as the UE 120 travels farther from the base station 110, the base station 110 can determine an extended guard interval according to the updated time delay associated with the UE 120 that is farthest from the base station 110. The base station 110 can update the guard interval according to the periodic reports of the identified timing differences or location information received from multiple UEs 120 in the cell associated with the base station 110.

[0069] As indicated by reference numeral 640, the base station 110 can send and the UE 120 can receive the scheduling configuration identifying the guard interval. The base station 110 can send the scheduling configuration to the UE 120 via radio resource control (RRC) signaling or downlink control information (DCI). The scheduling configuration can identify the guard interval between the intervals (e.g., time slots) allocated for downlink transmission and the intervals (e.g., time slots) allocated for uplink transmission.

[0070] In some aspects, the scheduling configuration can identify the blank intervals for the UE 120 to avoid interfering with the downlink transmission of the base station 110. The base station 110 can determine the duration of the blank intervals based at least in part on the timing differences or locations reported by the UE 120. For example, the base station 110 can determine different (e.g., shorter) blank intervals for a first UE 120 that is closer to the base station 110 (e.g., closer to the center of the cell) than for a second UE 120 that is farther from the base station 110 (e.g., away from the center of the cell).

[0071] In some aspects, the scheduling configuration can identify a timeline for at least one of K0 timing, K1 timing, or K2 timing. K0 timing refers to the timing between a downlink resource grant on a Physical Downlink Control Channel (PDCCH) and a downlink data transmission on a Physical Downlink Shared Channel (PDSCH). K1 timing refers to the timing between a downlink data transmission on the PDSCH and an uplink Acknowledgment (ACK) or Negative ACK (NACK) on a Physical Uplink Control Channel (PUCCH). K2 timing refers to the timing between an uplink resource grant on the PDCCH and an uplink data transmission on a Physical Uplink Shared Channel (PUSCH). The base station 110 can determine the timeline at least in part based on the timing difference or location reported by the UE 120. Accordingly, the base station 110 can determine a different timeline for a first UE 120 that is closer to the base station 110 (e.g., closer to the center of the cell) than for a second UE 120 that is farther from the base station 110 (e.g., farther from the center of the cell).

[0072] In some aspects, the scheduling configuration can identify a timeline for at least one of K0 timing, K1 timing, or K2 timing that is not adjusted based on the timing difference or location reported by the UE 120. In such a case, the UE 120 can adjust one or more of K0 timing, K1 timing, or K2 timing at least in part based on the timing difference for the UE 120 or the location of the UE 120. For example, the UE 120 can determine an adjusted K1 timing by reducing the K1 timing by the round-trip delay of the UE 120 (e.g., 2 × propagation delay), or can determine an adjusted K2 timing by reducing the K2 timing by the round-trip delay of the UE 120.

[0073] According to the scheduling configuration, the UE 120 can send an uplink transmission to the base station 110 or receive a downlink transmission from the base station 110.

[0074] As described above, provide Figure 6 as an example. Other examples may be different from the examples described with respect to Figure 6 what is described.

[0075] Figure 7 is a diagram illustrating an example 700 of an ATG communication schedule according to various aspects of the present disclosure. As Figure 7 shown, the base station 110 and the UE 120 can perform ATG communication. In some aspects, as described in more detail above in connection with Figure 6 the UE 120 can receive a downlink transmission 710 from the base station 110 and send an uplink transmission 720 to the base station 110 according to a scheduling configuration provided by the base station 110. As Figure 7As shown, example 700 may relate to a guard interval 730 determined by base station 110 (as described in more detail above in connection with Figure 6 ), which is equal to the TA 750 of UE 120 (e.g., when UE 120 is 150 kilometers away from base station 110, guard interval 730 may be equal to TA 750). In some aspects, guard interval 730 may be less than the TA 750 of UE 120 (e.g., when UE 120 is more than 150 kilometers away from base station 110). For example, when the guard interval is a fixed value (e.g., a fixed value based at least in part on the minimum time delay of the cell, such as a minimum time delay based on a distance less than 150 kilometers), guard interval 730 may be less than or equal to the TA 750 of UE 120.

[0076] In such a case, base station 110 may determine the downlink transmission 710 that will conflict with the uplink transmission 720 of UE 120 based at least in part on the timing difference (e.g., propagation delay 740 or TA 750) or location reported by UE 120. For example, based at least in part on the timing difference or location reported by UE 120 and the duration of guard interval 730, base station 110 may determine that the uplink transmission 720 of UE 120 will be sent in the interval (e.g., time slot) scheduled for the downlink transmission 710 of base station 110. As Figure 7 shown, the uplink transmission 720 according to TA 750 may conflict with the downlink transmission (D4) 710.

[0077] In some aspects, base station 110 may schedule the downlink transmission 710 and / or the uplink transmission 720 to avoid conflicts. For example, based at least in part on the timing difference (e.g., propagation delay 740 or TA 750) or location reported by UE 120, base station 110 may determine the interval (e.g., time slot D4) in which a conflict will occur and schedule the downlink transmission 710 in a different interval (e.g., a different time slot). In some aspects, such as when a conflict is to occur, UE 120 may skip the downlink transmission 710 (e.g., according to the scheduling indication provided by base station 110) in order to send the uplink transmission 720. In this case, base station 110 may provide uplink authorization (e.g., based on the timing difference or location) in one or more downlink transmissions 710 that UE 120 does not skip.

[0078] In some aspects, such as when a conflict is to occur, UE 120 may delay the uplink transmission 720 to an available (e.g., non-conflicting) interval (e.g., an available time slot). Alternatively, UE 120 may discard the uplink transmission 720, and base station 110 may subsequently schedule the discarded uplink transmission 720.

[0079] In some aspects, such as when a conflict is to occur, the base station 110 may send an indication (e.g., via DCI) to the UE 120 that it is to receive the downlink transmission 710. For example, the base station 110 may send the indication at least in part based on a determination that the downlink transmission 710 is not scheduled in an interval (e.g., time slot D4). Additionally or alternatively, the UE 120 may determine that it is to receive the downlink transmission 710 at least in part based on a determination that it has not received an uplink grant from the base station 110 for an interval (e.g., time slot D4).

[0080] In some aspects, the base station 110 may schedule a blank interval 760 (e.g., one or more symbols or one or more time slots) for the UE 120 to avoid interfering with the downlink transmission 710 of the base station 110. The base station 110 may determine the duration of the blank interval 760 at least in part based on a timing difference (e.g., propagation delay 740 or TA 750) or location reported by the UE 120. For example, the base station 110 may determine a different (e.g., shorter) blank interval 760 for a first UE 120 that is closer to the base station 110 (e.g., closer to the center of the cell) than for a second UE 120 that is farther from the base station 110 (e.g., farther from the center of the cell).

[0081] In some aspects, when a conflict is to occur, the uplink transmission 720 may be given a higher priority than the downlink transmission 710. For example, when the uplink transmission conflicts with a configured downlink transmission (e.g., configured via RRC), a semi-statically scheduled uplink transmission, a semi-statically scheduled downlink transmission, etc., the UE 120 may send the uplink transmission according to an uplink grant scheduled by DCI (e.g., dynamically scheduled). As another example, the UE 120 may send an uplink transmission associated with another basic signal that conflicts with a sounding reference signal, a random access procedure, and / or a configured downlink transmission. In some aspects, the UE 120 may receive a downlink transmission that conflicts with a configured uplink transmission and is associated with discontinuous reception scheduling, a control resource set (CORESET, e.g., CORESET#0), a synchronization signal block, or other basic information.

[0082] In addition, in some aspects, the TA 750 of the UE 120 for downlink scheduling and uplink scheduling may be based on different time intervals. For example, the UE 120 may use the TA 750 of one or more time slots for downlink scheduling on a time-slot basis, and the UE 120 may use the TA 750 of one or more symbols for uplink scheduling on a symbol basis. In some aspects, the UE 120 may determine the TA 750 as one or more symbols based on a random access procedure with the base station 110.

[0083] As described above, provided Figure 7 as an example. Other examples may be different from the example described with respect to Figure 7 the example described.

[0084] Figure 8 FIG. is a diagram illustrating an example process 800, such as performed by a base station, in accordance with various aspects of the present disclosure. Example process 800 is an example of operations performed by a base station (e.g., base station 110, etc.) associated with scheduling communication for ATG.

[0085] As Figure 8 shown, in some aspects, process 800 may include determining a guard interval (block 810) that is less than a maximum time delay for ATG communication, at least in part based on the radius of a cell. For example, as described above, a base station (e.g., using controller / processor 240, etc.) may determine a guard interval that is less than a maximum time delay for ATG communication, at least in part based on the radius of a cell.

[0086] As Figure 8 further shown, in some aspects, process 800 may include sending a scheduling configuration that identifies the guard interval to a UE (block 820). For example, a base station (e.g., using controller / processor 240, transmit processor 220, TX MIMO processor 230, MOD 232, antenna 234, etc.) may send a scheduling configuration that identifies the guard interval to a UE, as described above.

[0087] Process 800 may include additional aspects, such as any single aspect or any combination of aspects described below and / or related to one or more other processes described elsewhere herein.

[0088] In a first aspect, the maximum time delay includes a maximum round-trip delay that is at least in part based on the radius of the cell, and a round-trip downlink-uplink transition delay of the UE.

[0089] In a second aspect, alone or in combination with the first aspect, process 800 further includes receiving information that identifies a timing difference for the UE or information that identifies the location of the UE. In a third aspect, alone or in combination with one or more of the first and second aspects, the scheduling configuration identifies a timeline that is at least in part based on the timing difference or location, and the timeline is for at least one of K0 timing, K1 timing, or K2 timing. In a fourth aspect, alone or in combination with one or more of the first through third aspects, the scheduling configuration identifies a blank interval that is at least in part based on the timing difference or location.

[0090] In a fifth aspect, alone or in combination with one or more of the first to fourth aspects, process 800 further includes determining a downlink transmission to conflict with the uplink transmission of the UE, at least in part based on a timing difference or a location. In a sixth aspect, alone or in combination with one or more of the first to fifth aspects, process 800 further includes scheduling the downlink transmission to avoid conflicting with the uplink transmission. In a seventh aspect, alone or in combination with one or more of the first to sixth aspects, process 800 further includes sending an indication that the UE is to receive a downlink transmission, at least in part based on a determination that the uplink transmission is not scheduled. In an eighth aspect, alone or in combination with one or more of the first to seventh aspects, process 800 further includes scheduling the uplink transmission and not scheduling the downlink transmission.

[0091] In a ninth aspect, alone or in combination with one or more of the first to eighth aspects, the timing difference is a timing advance or a propagation delay. In a tenth aspect, alone or in combination with one or more of the first to ninth aspects, the timing advance is one or more time slots or one or more symbols.

[0092] In an eleventh aspect, alone or in combination with one or more of the first to tenth aspects, the guard interval is greater than or equal to the time delay associated with the UE that is furthest from the base station, and the furthest UE is attached to the cell. In a twelfth aspect, alone or in combination with one or more of the first to eleventh aspects, the time delay includes a round-trip delay that is at least in part based on the distance of the UE that is furthest from the base station and a round-trip downlink-uplink transition delay of the furthest UE. In a thirteenth aspect, alone or in combination with one or more of the first to twelfth aspects, process 800 further includes receiving, from each of a plurality of UEs in the cell, at least one of information identifying the timing difference and information identifying the location, and determining the furthest UE, at least in part based on at least one of the information identifying the timing difference and the information identifying the location. In a fourteenth aspect, alone or in combination with one or more of the first to thirteenth aspects, process 800 further includes sending an updated scheduling configuration that identifies a shortened guard interval that is at least in part based on an updated timing difference or an updated location of the UE that is furthest from the base station.

[0093] Although Figure 8 example blocks of process 800 are shown, in some aspects, process 800 may include additional blocks, fewer blocks, different blocks, or differently arranged blocks compared to those depicted in Figure 8 . Additionally or alternatively, two or more blocks of process 800 may be executed in parallel.

[0094] Figure 9FIG. 0 is a diagram illustrating an example process 900, such as may be performed by a UE, in accordance with various aspects of the present disclosure. Example process 900 is an example of operations performed by a UE (e.g., UE 120, etc.) associated with scheduling communication with an ATG.

[0095] As Figure 9 shown, in some aspects, process 900 may include receiving a scheduling configuration that identifies a guard interval less than a maximum time delay for ATG communication that is at least partially based on the radius of a cell (block 910). For example, as described above, a UE (e.g., using antenna 252, DEMOD 254, MIMO detector 256, receive processor 258, controller / processor 280, etc.) may receive a scheduling configuration that identifies a guard interval less than a maximum time delay for ATG communication that is at least partially based on the radius of a cell.

[0096] As Figure 9 further shown, in some aspects, process 900 may include transmitting or receiving a communication in accordance with the scheduling configuration (block 920). For example, a UE (e.g., using transmit processor 220, TX MIMO processor 230, MOD 232, antenna 234, antenna 252, DEMOD 254, MIMO detector 256, receive processor 258, controller / processor 280, etc.) may transmit or receive a communication in accordance with the scheduling configuration, as described above.

[0097] Process 900 may include additional aspects, such as any individual aspect or any combination of aspects described below and / or related to one or more other processes described elsewhere herein.

[0098] In a first aspect, the maximum time delay includes a maximum round-trip delay that is at least partially based on the radius of a cell, and a round-trip downlink-uplink transition delay of the UE.

[0099] In a second aspect, alone or in combination with the first aspect, process 900 further includes receiving a timeline for at least one of K1 timing and K2 timing, and determining at least one of an adjusted K1 timing by reducing the round-trip delay of the UE from the K1 timing and an adjusted K2 timing by reducing the round-trip delay of the UE from the K2 timing.

[0100] In a third aspect, alone or in combination with one or more of the first and second aspects, process 900 further includes sending information identifying a timing difference for the UE or information identifying the location of the UE. In a fourth aspect, alone or in combination with one or more of the first to third aspects, the scheduling configuration identifies a timeline that is at least partially based on the time difference or location, and the timeline is for at least one of K0 timing, K1 timing, or K2 timing. In a fifth aspect, alone or in combination with one or more of the first to fourth aspects, the scheduling configuration identifies a guard interval that is at least partially based on the timing difference or location.

[0101] In a sixth aspect, alone or in combination with one or more of the first to fifth aspects, process 900 further includes receiving a downlink transmission in an interval for uplink transmission, at least partially based on the timing difference and an indication that the uplink transmission is not scheduled. In a seventh aspect, alone or in combination with one or more of the first to sixth aspects, process 900 further includes sending an uplink transmission according to the timing difference and in an interval allocated for downlink transmission.

[0102] In an eighth aspect, alone or in combination with one or more of the first to seventh aspects, the timing difference is a timing advance or a propagation delay. In a ninth aspect, alone or in combination with one or more of the first to eighth aspects, the timing advance is one or more time slots or one or more symbols. In a tenth aspect, alone or in combination with one or more of the first to ninth aspects, the timing advance is one or more time slots and is determined based on a random access procedure.

[0103] In an eleventh aspect, alone or in combination with one or more of the first to tenth aspects, the guard interval is greater than or equal to a time delay associated with the UE that is farthest from the base station serving the UE, and the farthest UE is attached to the cell. In a twelfth aspect, alone or in combination with one or more of the first to eleventh aspects, the time delay includes a round-trip delay that is at least partially based on the distance of the UE that is farthest from the base station and a round-trip downlink-uplink transition delay of the farthest UE. In a thirteenth aspect, alone or in combination with one or more of the first to twelfth aspects, process 900 further includes receiving an updated scheduling configuration that identifies a shortened guard interval that is at least partially based on an updated timing difference or updated location of the UE that is farthest from the base station.

[0104] In a fourteenth aspect, alone or in combination with one or more of the first through thirteenth aspects, process 900 further includes transmitting an uplink transmission according to a dynamically scheduled uplink grant when the uplink transmission conflicts with a configured downlink transmission or a semi-statically scheduled downlink transmission. In a fifteenth aspect, alone or in combination with one or more of the first through fourteenth aspects, process 900 further includes transmitting an uplink transmission that conflicts with a configured downlink transmission and that is associated with a sounding reference signal or a random access procedure. In a sixteenth aspect, alone or in combination with one or more of the first through fifteenth aspects, process 900 further includes receiving a downlink transmission that conflicts with a configured uplink transmission and that is associated with discontinuous reception scheduling, a control resource set, or a synchronization signal block.

[0105] Although Figure 9 example boxes of process 900 are shown, in some aspects, process 900 may include additional boxes, fewer boxes, different boxes, or boxes in a different arrangement compared to those depicted in Figure 9 . Additionally or alternatively, two or more boxes of process 900 may be executed in parallel.

[0106] The foregoing disclosure provides illustration and description, but is not intended to be exhaustive or to limit the aspects to the precise forms disclosed. Modifications and variations may be made in light of the above disclosure or may be acquired from practice of these aspects.

[0107] As used herein, the term "component" is intended to be broadly interpreted as hardware, firmware, and / or a combination of hardware and software. As used herein, a processor is implemented as hardware, firmware, and / or a combination of hardware and software.

[0108] As used herein, depending on the context, meeting a threshold may mean that a value is greater than a threshold, greater than or equal to a threshold, less than a threshold, less than or equal to a threshold, equal to a threshold, not equal to a threshold, etc.

[0109] It is apparent that the systems and / or methods described herein may be implemented in different forms of hardware, firmware, and / or combinations of hardware and software. The actual special control hardware or software code used to implement these systems and / or methods does not limit these aspects. Accordingly, the operations and behavior of the systems and / or methods are 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 at least in part based on the description herein.

[0110] Although specific combinations of features are recited in the claims and / or disclosed in the specification, these combinations are not intended to limit the disclosure of the various aspects. In fact, many of these features may be combined in ways not specifically recited in the claims and / or disclosed in the specification. Although each dependent claim listed below may directly depend only on one claim, the disclosure of the 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 means any combination of these items including a single member. As an example, "at least one of a, b, and c" is intended to cover a, b, c, ab, ac, bc, and abc, as well as any combination having multiple of the same element (e.g., aa, aaa, aab, aac, abb, acc, bb, bbb, bbc, cc, and ccc or any other order of a, b, and c).

[0111] Unless expressly described as such, any element, act, or instruction used herein shall not be construed as critical or essential. Further, 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." Further, as used herein, the terms "set" and "group" are intended to include one or more items (e.g., related items, unrelated items, combinations of related and unrelated items, etc.) and may be used interchangeably with "one or more." If only one item is intended, the phrase "only one" or similar language is used. Further, as used herein, the terms "has," "have," "having," etc. are intended to be open-ended terms. Further, unless expressly stated otherwise, the phrase "based on" is intended to mean "at least partially based on."

Claims

1. A method of wireless communication performed by a base station associated with a cell of a time division duplex communication system, comprising: determining a guard interval associated with air-to-ground communication with a plurality of user equipment (UE), wherein the guard interval: is less than a maximum time delay of air-to-ground communication in the cell, the maximum time delay being at least partially based on the radius of the cell, and is greater than or equal to a time delay associated with the farthest UE associated with the base station; and sending a scheduling configuration identifying the guard interval to the UEs of the plurality of UEs.

2. The method according to claim 1, wherein, the maximum time delay includes a maximum round-trip delay at least partially based on the radius of the cell and a round-trip downlink-uplink conversion delay of the UE.

3. The method according to claim 1, further comprising: receiving information identifying a timing difference for the UE or information identifying a location of the UE.

4. The method according to claim 3, wherein, the scheduling configuration identifies a timeline at least partially based on the timing difference or the location, wherein the timeline is for at least one of K0 timing, K1 timing, or K2 timing.

5. The method according to claim 3, wherein, the scheduling configuration identifies a blank interval at least partially based on the timing difference or the location.

6. The method according to claim 3, further comprising: determining a downlink transmission to conflict with an uplink transmission of the UE at least partially based on the timing difference or the location.

7. The method according to claim 6, further comprising: scheduling the downlink transmission to avoid a conflict with the uplink transmission.

8. The method according to claim 6, further comprising: sending an indication to the UE to receive the downlink transmission at least partially based on a determination that the uplink transmission is not scheduled.

9. The method according to claim 6, further comprising: scheduling the uplink transmission and not scheduling the downlink transmission.

10. The method according to claim 3, wherein, the timing difference is a timing advance or a propagation delay.

11. The method according to claim 1, wherein, the farthest UE is attached to the cell.

12. The method according to claim 1, wherein, the time delay includes a round-trip delay at least partially based on the distance of the farthest UE, and a round-trip downlink-uplink conversion delay of the farthest UE.

13. The method according to claim 1, further comprising: receiving from each of the plurality of UEs in the cell at least one of information identifying a timing difference and information identifying a location; and determining the farthest UE at least partially based on at least one of the information identifying the timing difference and the information identifying the location.

14. The method according to claim 1, further comprising sending an updated scheduling configuration, the updated scheduling configuration identifying a shortened guard interval at least partially based on an updated timing difference or an updated location of the farthest UE from the base station.

15. A method of wireless communication performed by a user equipment (UE) of a time division duplex communication system, comprising: receiving a scheduling configuration that identifies a guard interval associated with air-to-ground communication with multiple UEs, wherein the guard interval: is less than a maximum time delay of air-to-ground communication in a cell, where the UE is located in the cell, the maximum time delay being at least partially based on the radius of the cell, and is greater than or equal to a time delay associated with the farthest UE associated with a base station of the cell; and sending or receiving communication according to the scheduling configuration.

16. The method according to claim 15, wherein, the maximum time delay includes a maximum round-trip delay at least partially based on the radius of the cell, and a round-trip downlink-uplink conversion delay of the UE.

17. The method according to claim 15, further comprising: receiving a timeline for at least one of K1 timing and K2 timing; and determining at least one of: an adjusted K1 timing by reducing the round-trip delay of the UE from the K1 timing, and an adjusted K2 timing by reducing the round-trip delay of the UE from the K2 timing.

18. The method according to claim 15, further comprising: sending information identifying a timing difference for the UE or information identifying a location of the UE.

19. The method according to claim 18, wherein, the scheduling configuration identifies a timeline at least partially based on the timing difference or the location, wherein the timeline is for at least one of K0 timing, K1 timing or K2 timing.

20. The method according to claim 18, wherein, the scheduling configuration identifies a blank interval at least partially based on the timing difference or the location.

21. The method according to claim 18, further comprising: receiving a downlink transmission in an interval for the uplink transmission, at least partially based on the timing difference and an indication that the uplink transmission is not scheduled.

22. The method according to claim 18, further comprising: sending an uplink transmission according to the timing difference and in an interval allocated for the downlink transmission.

23. The method according to claim 18, wherein, the timing difference is a timing advance or a propagation delay.

24. The method according to claim 23, wherein, the timing advance is one or more time slots or one or more symbols.

25. The method according to claim 24, wherein, the timing advance is the one or more time slots and is determined based on a random access procedure.

26. The method according to claim 15, wherein, the farthest UE is attached to the cell.

27. The method according to claim 15, wherein, the time delay includes a round-trip delay at least partially based on the distance of the farthest UE, and a round-trip downlink-uplink conversion delay of the farthest UE.

28. The method according to claim 15, further comprising: Receive an updated scheduling configuration that identifies a shortened guard interval that is at least partially based on an updated timing difference or updated location of the furthest UE from the base station.

29. The method according to claim 15, further comprising: When an uplink transmission conflicts with a configured downlink transmission or a semi-statically scheduled downlink transmission, send the uplink transmission according to a dynamically scheduled uplink grant.

30. The method according to claim 15, further comprising: Send an uplink transmission that is associated with a sounding reference signal or a random access procedure and that conflicts with a configured downlink transmission.

31. The method according to claim 15, further comprising: Receive a downlink transmission that is associated with discontinuous reception scheduling, a control resource set, or a synchronization signal block and that conflicts with a configured uplink transmission.

32. A user equipment (UE) for wireless communication in a time division duplex communication system, comprising: a memory; and one or more processors operably coupled to the memory, the memory and the one or more processors being configured to: Receive a scheduling configuration that identifies a guard interval associated with air-to-ground communication with multiple UEs, wherein the guard interval: Is less than the maximum time delay of air-to-ground communication in the cell, where the UE is located in the cell, the maximum time delay being at least partially based on the radius of the cell, and Is greater than or equal to the time delay associated with the furthest UE associated with the base station of the cell; and Send or receive communication according to the scheduling configuration.

33. The UE according to claim 32, wherein The memory and the one or more processors are further configured to receive a downlink transmission in an interval for the uplink transmission at least partially based on a timing difference and an indication that the uplink transmission is not scheduled.

34. The UE according to claim 32, wherein The memory and the one or more processors are further configured to send an uplink transmission according to a timing difference and in an interval allocated for a downlink transmission.

35. An apparatus for wireless communication associated with a cell of a time division duplex communication system, comprising: Means for determining a guard interval associated with air-to-ground communication with multiple user equipment (UEs), wherein the guard interval: Is less than the maximum time delay of air-to-ground communication in the cell, the maximum time delay being at least partially based on the radius of the cell, and Is greater than or equal to the time delay associated with the furthest UE associated with the apparatus; and Means for sending a scheduling configuration identifying the guard interval to the UEs of the multiple UEs.

36. A non-transitory computer-readable medium storing one or more instructions for wireless communication, the one or more instructions, when executed by one or more processors of a base station associated with a cell of a time division duplex communication system, cause the base station to: Determine a guard interval associated with air-to-ground communication with multiple user equipment (UEs), wherein the guard interval: Less than the maximum time delay of the air-to-ground communication in the cell, the maximum time delay being at least partially based on the radius of the cell, and Greater than or equal to the time delay associated with the farthest UE associated with the base station; and Send a scheduling configuration identifying the guard interval to the UEs of the plurality of UEs.

37. A non-transitory computer-readable medium storing one or more instructions for wireless communication, the one or more instructions, when executed by one or more processors of a user equipment UE of a time division duplex communication system, cause the UE to: Receive a scheduling configuration that identifies a guard interval for air-to-ground communication that is less than a maximum time delay based at least in part on the radius of the cell in which the UE is located, where the guard interval: Is less than the maximum time delay of the air-to-ground communication in the cell, where the UE is located in the cell, the maximum time delay being at least partially based on the radius of the cell, and Is greater than or equal to the time delay associated with the farthest UE associated with the base station of the cell; and Send or receive communication according to the scheduling configuration.

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