Semi-static and dynamic TDD configurations for 5G-NR

Abstract

The present disclosure relates to semi-static and dynamic TDD configurations for 5G‑NR. The TDD configuration may be dynamically and / or semi-statically signaled by a base station to a user equipment device. The semi-static TDD configuration may include: an initial portion, which is used for downlink transmission; a flexible portion; and a termination portion, which is used for uplink transmission. The TDD 5 structure of the flexible portion may be determined later by transmitting dynamic physical layer configuration information such as downlink control information (DCI) and / or a slot format indicator (SFI). (The SFI may be included in the group common PDCCH of the time slot.) The downlink portion and / or the uplink portion may include a subset whose nominal transmission direction is overwritten by the transmission of the dynamic physical layer configuration information.

Description

[0001] This application is a divisional application of PCT international application No. 201880039462.0, which entered the Chinese national phase and whose international application date is May 22, 2018 and whose invention name is “Semi-static and dynamic TDD configuration for 5G-NR”. Technical Field

[0002] The present application relates to wireless communications, and more particularly, to a mechanism for flexibly signaling the transmission format of a time slot in a radio frame. Background Art

[0003] A mechanism is needed for signaling the UE about the time division duplex (TDD) structure of a timeslot or a group of timeslots in a radio frame. Summary of the invention

[0004] Embodiments of apparatus, systems, and methods for utilizing flexible slot indicators in wireless communications are provided herein.

[0005] In one set of embodiments, a method for operating a base station may include the following operations.

[0006] The method may include: transmitting, by a radio component of a base station, a first slot format indicator (SFI) in a first slot of a radio frame, wherein the first SFI may indicate a first transmission direction of at least a first portion of the first slot, wherein the first transmission direction is either an uplink transmission or a downlink transmission. The SFI may be included in a group common PDCCH of a PDCCH region of the first slot, wherein the PDCCH region spans the first N symbol durations of the first slot, wherein N is greater than or equal to one. In some embodiments, N is equal to one. In some embodiments, the first SFI indicates that the PDCCH region includes at least one PDCCH. In some embodiments, the first SFI indicates that the PDCCH region does not include a PDCCH.

[0007] In some embodiments, the first SFI further indicates a second transmission direction for a second portion of the first time slot, wherein the second transmission direction is a direction opposite to the first transmission direction. In some embodiments, the first SFI further indicates a second transmission direction for at least a portion of a second time slot, wherein the second time slot immediately follows the first time slot, wherein the second transmission direction is a direction opposite to the first transmission direction. In some embodiments, the first transmission direction is an uplink transmission, wherein the first SFI indicates a time slot aggregation level for uplink transmission. In some embodiments, the first transmission direction is a downlink transmission, wherein the first SFI indicates a time slot aggregation level for downlink transmission.

[0008] In some embodiments, SFI may cancel RRC configured periodic signal transmission / reception, such as CSI-RS measurement results or SRS transmission.

[0009] In some embodiments, the SFI may be divided into two parts (transmission direction and aggregation level) and encoded separately.

[0010] In some embodiments, the first transmission direction is a downlink transmission, wherein the range of timeslot aggregation for downlink transmission is indicated in the DCI of the radio frame containing the first timeslot.

[0011] In some embodiments, the method also includes receiving, by the radio component, a second SFI in a second time slot of the radio frame, wherein the second time slot immediately follows the first time slot, wherein the second SFI indicates a second transmission direction of at least a portion of the second time slot, wherein the second transmission direction is either an uplink transmission or a downlink transmission, and wherein the second SFI is included in a group common PDCCH of a PDCCH region of the second time slot.

[0012] In some embodiments, the second SFI indicates that the PDCCH region of the second time slot does not include a PDCCH.

[0013] In some embodiments, the method further comprises transmitting, by the radio component, a second SFI in a second time slot of the radio frame, wherein the second SFI indicates that at least a portion of the second time slot is blank, wherein the second SFI is included in a group common PDCCH of a PDCCH region of the second time slot.

[0014] In some embodiments, the method also includes transmitting, by the radio component, a second SFI in a second time slot of the radio frame, wherein the second SFI indicates that at least a portion of the second time slot is to be used for a side link (such as UE to UE or V2X), wherein the second SFI is included in a group common PDCCH in a PDCCH region of the second time slot.

[0015] In some embodiments, the length of a radio frame slot is two or 7 or 14 symbols.

[0016] In one set of embodiments, a method for operating a user equipment device may include: receiving, by a radio component of the user equipment device, TDD configuration information, wherein the TDD configuration information includes parameters defining a semi-static TDD configuration for a frame structure. The parameters may include:

[0017] frame length, which specifies the duration of the frame structure;

[0018] a first length specifying a duration of a downlink portion of the frame structure, wherein the downlink portion occupies an initial position within the frame structure; and

[0019] a second length specifying a duration of an uplink portion of the frame structure, wherein the uplink portion occupies a terminal position within the frame structure;

[0020] The middle part of the frame structure appears after the downlink part and before the uplink part.

[0021] The TDD structure of the middle part is not determined by the TDD configuration information.

[0022] In response to receiving the TDD configuration information, the method may include performing TDD operations including: receiving, by the radio component, downlink data from within a downlink portion of the frame structure; and transmitting, by the radio component, uplink data within an uplink portion of the frame structure.

[0023] In some embodiments, the method may further include: receiving one or more physical layer signals (such as SFI and / or DCI) that dynamically determine the TDD structure of the middle portion; and performing TDD operations on the middle portion based on the dynamically determined TDD structure.

[0024] In one set of embodiments, a method for operating a user equipment device may include receiving, by a radio component of the user equipment device, a TDD configuration index. The TDD configuration index may have a value selected from a predefined set of values. The values ​​of the predefined set may identify a corresponding semi-static TDD configuration. A first subset of the values ​​of the predefined set may identify a semi-static TDD configuration that is consistent with a corresponding TDD configuration of 3GPP LTE up to a time shift (cyclic or non-cyclic), for example, as described below in various ways.

[0025] In some embodiments, the predefined set includes values ​​of a second subset that is non-intersecting with the first subset, wherein for each value in the second subset, the corresponding semi-static TDD configuration includes: an initial part, which includes one or more consecutive time slots for downlink transmission; a terminal part, which includes one or more consecutive time slots for uplink transmission; and a middle part, which includes one or more consecutive time slots, and the TDD structure of the consecutive time slots will be dynamically determined by physical layer configuration information.

[0026] In one set of embodiments, a method for operating a user equipment device may include receiving, by a radio component of the user equipment device, physical layer configuration information from a first time slot of a plurality of time slots in a current frame. The physical layer configuration information may dynamically determine a TDD state (e.g., a transmission direction) of at least a portion of a designated time slot of the current frame, wherein the designated time slot is a first time slot in the current frame or a second time slot occurring after the first time slot.

[0027] In some embodiments, the physical layer configuration information may include a slot format indicator, wherein the slot format indicator is included in a group common PDCCH of the first slot.

[0028] In some embodiments, the physical layer configuration information includes downlink control information (DCI).

[0029] It should be noted that the techniques described herein may be implemented in and / or used with a number of different types of devices, including but not limited to base stations, access points, cellular telephones, portable media players, tablet computers, wearable devices, and various other computing devices.

[0030] The present disclosure is intended to provide a brief overview of some of the themes described in this document. Therefore, it should be understood that the above features are only examples and should not be interpreted as narrowing the scope or essence of the themes described herein in any way. Other features, aspects and advantages of the themes described herein will become apparent through the following detailed description, drawings and claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] A better understanding of embodiments of the present invention may be obtained when the following detailed description of the preferred embodiments is considered in conjunction with the following drawings.

[0032] Figure 1 An exemplary (and simplified) wireless communication system according to some embodiments is shown;

[0033] Figure 2 illustrates an exemplary base station in communication with an exemplary wireless user equipment (UE) device according to some embodiments;

[0034] Figure 3 is an exemplary block diagram of a UE according to some embodiments;

[0035] Figure 4 is an exemplary block diagram of a base station according to some embodiments;

[0036] Figure 5A shows an exemplary TDD configuration according to some embodiments;

[0037] Figure 5B illustrates an exemplary special subframe according to some embodiments;

[0038] Figure 5C and Figure 5D shows an exemplary special subframe format according to some embodiments;

[0039] Figure 6illustrates exemplary UL reference configurations and DL reference configurations according to some embodiments;

[0040] Figure 7 According to some embodiments, Figure 6 An exemplary effective TDD frame structure obtained by an embodiment of the present invention;

[0041] Figure 8 An example of a TDD frame structure including each time slot according to some embodiments is shown;

[0042] Fig. 9 and Fig.10 shows an exemplary time slot format according to some embodiments;

[0043] Figure 11-Figure 28 illustrates an exemplary time slot format according to some embodiments;

[0044] Fig.29 and Fig.30 An exemplary method for using a slot format indicator according to some embodiments is shown;

[0045] Fig.31 shows an exemplary format according to some embodiments;

[0046] Figure 32A-32C shows an exemplary TDD configuration that may be made compatible with the TDD configuration of LTE according to some embodiments;

[0047] Fig.33 illustrates an exemplary specialized subframe according to some embodiments;

[0048] Fig.34 illustrates an exemplary alignment of LTE and NR formats according to some embodiments;

[0049] Fig.35 and Fig.36 shows an exemplary format sequence according to some embodiments;

[0050] Figure 37A-Figure 37E presents examples of how a flexible portion of a frame structure having a single time slot may be specialized in different ways according to some embodiments;

[0051] Fig.38 shows a cycle-SCS combination according to some embodiments;

[0052] Fig.39 shows an exemplary table showing a set of supported slot lengths for NR according to some embodiments;

[0053] Figure 40-Figure 43shows an exemplary TDD configuration applicable to NR according to some embodiments;

[0054] Figure 44-Figure 46 shows an exemplary format corresponding to a potential override of a transfer direction according to some embodiments;

[0055] Figure 47-Figure 49 An exemplary method for semi-static TDD configuration according to some embodiments is shown;

[0056] Fig.50 shows an exemplary configuration with variable length for downlink and uplink according to some embodiments;

[0057] Fig.51A and Fig.51B shows an implementation according to some embodiments, wherein the DCI overrides the transmission direction indicated by the SFI in time slot n+3 while protecting the configured periodic signal; and

[0058] Figure 52-Figure 60 Exemplary methods for specifying a transmission direction according to various embodiments are shown.

[0059] Although the embodiments described herein are susceptible to various modifications and alternative forms, specific embodiments thereof are shown by way of example in the drawings and described in detail herein. However, it should be understood that the drawings and detailed description are not intended to limit the embodiments to the particular forms disclosed, but on the contrary, the purpose is to cover all modifications, equivalents and alternative forms that fall within the spirit and scope of the embodiments of the present invention as defined by the appended claims. DETAILED DESCRIPTION

[0060] Acronyms

[0061] ARQ: Automatic Repeat Request

[0062] CSI: Channel State Information

[0063] CSI-RS: CSI Reference Signal

[0064] DCI: Downlink Control Information

[0065] DL: Downlink

[0066] gNB: gNodeB

[0067] LTE: Long Term Evolution

[0068] NW: Network

[0069] NR: New Radio

[0070] PCFICH: Physical Control Format Indicator Channel

[0071] PDCCH: Physical Downlink Control Channel

[0072] PDSCH: Physical Downlink Shared Channel

[0073] PHICH: Physical Hybrid ARQ Indicator Channel

[0074] PUCCH: Physical Uplink Control Channel

[0075] PUSCH: Physical Uplink Shared Channel

[0076] RAT: Radio Access Technology

[0077] RNTI: Radio Network Temporary Identifier

[0078] RRC: Radio Resource Control

[0079] SIB: System Information Block

[0080] SIBn: System Information Block Type n

[0081] SL: Sidelink

[0082] SRS: Sounding Reference Signal

[0083] SSF: Special Subframe

[0084] TDD: Time Division Duplex

[0085] TTI: Transmission Time Interval

[0086] UE: User Equipment

[0087] UL: Uplink

[0088] the term

[0089] The following is a glossary of terms used in this disclosure:

[0090] Memory medium - any of various types of non-transitory memory devices or storage devices. The term "memory medium" is intended to include installation media, for example, CD-ROM, floppy disk or tape device; computer system memory or random access memory such as DRAM, DDR RAM, SRAM, EDO RAM, Rambus RAM, etc.; non-volatile memory such as flash memory, magnetic media, for example, hard disk drive or optical storage device; registers or other similar types of memory elements, etc. The memory medium may also include other types of non-transitory memory or a combination thereof. In addition, the memory medium may also be located in the first computer system executing the program, or may be located in a different second computer system connected to the first computer system via a network such as the Internet. In the latter case, the second computer system may provide program instructions to the first computer for execution. The term "memory medium" may include two or more memory media, which may reside in different locations in different computer systems connected, for example, via a network. The memory medium may store program instructions (e.g., expressed as a computer program) that may be executed by one or more processors.

[0091] Carrier Medium—storage media as described above, as well as physical transmission media such as a bus, network, and / or other physical transmission media that transport signals such as electrical, electromagnetic or digital signals.

[0092] Programmable hardware elements - include a variety of hardware devices that include multiple programmable function blocks connected via programmable interconnects. Examples include FPGAs (field programmable gate arrays), PLDs (programmable logic devices), FPOAs (field programmable object arrays), and CPLDs (complex PLDs). Programmable function blocks can range from fine-grained (combinational logic components or lookup tables) to coarse-grained (arithmetic logic units or processor cores). Programmable hardware elements may also be referred to as "reconfigurable logic" elements.

[0093] Computer System - Any of various types of computing or processing systems, including a personal computer system (PC), a mainframe computer system, a workstation, a network appliance, an Internet appliance, a personal digital assistant (PDA), a television system, a grid computing system, or other devices or combinations of devices. In general, the term "computer system" can be broadly defined to encompass any device (or combination of devices) having at least one processor that executes instructions from a memory medium.

[0094] User Equipment (UE) (or "UE device") - any of various types of computer system devices that are mobile or portable and perform wireless communications. Examples of UE devices include mobile phones or smart phones (e.g., iPhone TM , based on Android TMphones), portable gaming devices (e.g., Nintendo DS TM , PlayStation Portable TM 、Gameboy Advance TM , iPhone TM ), laptops, wearable devices (e.g., smart watches, smart glasses), PDAs, portable Internet devices, music players, data storage devices or other handheld devices, etc. In general, the term "UE" or "UE device" can be broadly defined to cover any electronic device, computing device and / or telecommunication device (or combination of devices) that can be easily transmitted by a user and capable of wireless communication.

[0095] Base Station—The term “base station” has the full breadth of its ordinary meaning and includes at least a wireless communication station that is installed at a fixed location and used to communicate as part of a wireless telephone system or radio system.

[0096] Processing Element - refers to various elements or combinations of elements. Processing elements include, for example, circuits such as ASICs (application specific integrated circuits), portions or circuits of individual processor cores, entire processor cores, individual processors, programmable hardware devices such as field programmable gate arrays (FPGAs), and / or larger portions of systems including multiple processors.

[0097] Channel - a medium used to transmit information from a sender (transmitter) to a receiver. It should be noted that since the characteristics of the term "channel" may vary according to different wireless protocols, the term "channel" as used herein may be considered to be used in a manner that conforms to the device type standard to which the term is used. In some standards, the channel width may be variable (e.g., depending on device capabilities, frequency band conditions, etc.). For example, LTE may support scalable channel bandwidths of 1.4 MHz to 20 MHz. In contrast, a WLAN channel may be 22 MHz wide, while a Bluetooth channel may be 1 MHz wide. Other protocols and standards may include different definitions of channels. In addition, some standards may define and use multiple types of channels, such as different channels for uplink or downlink and / or different channels for different purposes such as data, control information, etc.

[0098] Frequency band—The term “frequency band” has the full breadth of its ordinary meaning and includes at least a segment of the spectrum (eg, radio frequency spectrum) in which channels are used or set aside for the same purpose.

[0099] Automatic—refers to an action or operation performed by a computer system (e.g., software executed by a computer system) or a device (e.g., a circuit system, a programmable hardware element, an ASIC, etc.) without the need for user input to directly specify or perform the action or operation. Thus, the term "automatic" is in contrast to a user manually performing or specifying an action, where the user provides input to directly perform the action. An automatic process may be initiated by input provided by a user, but subsequent actions performed "automatically" are not specified by the user, i.e., are not performed "manually," where the user specifies each action to be performed. For example, a user filling out an electronic form by selecting each field and providing input specifying information (e.g., by typing in information, selecting check boxes, radio selections, etc.) is manually filling out the form, even though the computer system must update the form in response to the user action. The form may be automatically filled out by a computer system, where the computer system (e.g., software executed on the computer system) analyzes the fields of the form and fills out the form without any user input specifying the answers to the fields. As noted above, a user may invoke automatic filling out of a form, but not participate in the actual filling out of the form (e.g., the user does not manually specify the answers to the fields but rather they are automatically completed). This specification provides various examples of operations that are automatically performed in response to actions taken by a user.

[0100] Figure 1 and Figure 2 —Communications system

[0101] Figure 1 An exemplary (and simplified) wireless communication system according to one embodiment is shown. It should be noted that Figure 1 The system is only an example of one possible system, and the embodiments may be implemented in any of a variety of systems as desired.

[0102] As shown, the exemplary wireless communication system includes a base station 102A, which communicates with one or more user equipment 106A, user equipment 106B, etc. to user equipment 106N through a transmission medium. Each user equipment may be referred to as a "user equipment" (UE) in the present invention. Therefore, the user device 106 is referred to as a UE or a UE device.

[0103] Base station 102A may be a base transceiver station (BTS) or a cell site and may include hardware that enables wireless communications with UEs 106A to 106N. Base station 102A may also be equipped to communicate with network 100 (e.g., a core network of a cellular service provider, a telecommunications network such as a public switched telephone network (PSTN), and / or the Internet, among other possibilities). Thus, base station 102A may facilitate communications between user devices and / or between user devices and network 100.

[0104] The communication area (or coverage area) of a base station may be referred to as a “cell.” The base station 102A and the UE 106 may be configured to communicate via a transmission medium using any of a variety of radio access technologies (RATs), also referred to as wireless communication technologies or telecommunication standards, such as GSM, UMTS (WCDMA, TD-SCDMA), LTE, Advanced LTE (LTE-A), HSPA, 3GPP2 CDMA2000 (e.g., 1xRTT, 1xEV-DO, HRPD, eHRPD), Wi-Fi, WiMAX, New Radio (NR), etc.

[0105] Base station 102A and other similar base stations (such as base stations 102B...102N) operating according to the same or different cellular communication standards can therefore be provided as a network of cells that can provide continuous or nearly continuous overlapping service to UE 106A-N and similar devices over a wide geographic area via one or more cellular communication standards.

[0106] Therefore, although base station 102A may provide for Figure 1 106A-N, but each UE 106 may also be able to receive signals from (and possibly be within communication range of) one or more other cells (which may be provided by base stations 102B-N and / or any other base stations), which may be referred to as "neighboring cells." Such cells may also be able to facilitate communications between user devices and / or between user devices and network 100. Such cells may include "macro" cells, "micro" cells, "pico" cells, and / or cells that provide any of a variety of other granularities of service area size. For example, in Figure 1 The base stations 102A-B shown in FIG. 1 may be macro cells, while the base station 102N may be a micro cell. Other configurations are also possible.

[0107] It should be noted that UE 106 is capable of communicating using multiple wireless communication standards. For example, in addition to at least one cellular communication protocol (e.g., GSM, UMTS (WCDMA, TD-SCDMA), LTE, LTE-A, HSPA, 3GPP2 CDMA2000 (e.g., 1xRTT, 1xEV-DO, HRPD, eHRPD), NR, etc.), UE 106 can also be configured to communicate using wireless networking (e.g., Wi-Fi) and / or peer wireless communication protocols (e.g., BT, Wi-Fi, etc.). If desired, UE 106 may be additionally or alternatively configured to communicate using one or more global navigation satellite systems (GNSS, such as GPS or GLONASS), one or more mobile television broadcast standards (e.g., ATSC-M / H or DVB-H), and / or any other wireless communication protocols. Other combinations of wireless communication standards (including more than two wireless communication standards) are also possible.

[0108] Figure 2 A user device 106 (e.g., one of devices 106A to 106N) is shown communicating with a base station 102 (e.g., one of base stations 102A to 102N) according to one embodiment. UE 106 may be a device with cellular communication capabilities, such as a mobile phone, a handheld device, a wearable device, a computer or tablet, or substantially any type of wireless device.

[0109] UE106 may include a processor configured to execute program instructions stored in a memory. UE106 may perform any of the method embodiments described in the present invention by executing such stored instructions. Alternatively or in addition, UE106 may also include a programmable hardware element, such as an FPGA (field programmable gate array), which is configured to perform any of the method embodiments described herein or any part of any of the method embodiments described herein.

[0110] UE106 may include one or more antennas for communicating using one or more wireless communication protocols or technologies. In one embodiment, UE 106 may be configured to communicate using CDMA2000 (1xRTT / 1xEV-DO / HRPD / eHRPD) or LTE using a single shared radio component and / or any one of GSM or LTE using a single shared radio component. The shared radio component may be coupled to a single antenna, or may be coupled to multiple antennas (e.g., for MIMO) for performing wireless communications. Typically, the radio component may include any combination of the following: a baseband processor, an analog radio frequency (RF) signal processing circuit system (e.g., including filters, mixers, oscillators, amplifiers, etc.) or a digital processing circuit system (e.g., for digital modulation and other digital processing). Similarly, the radio component may use the aforementioned hardware to implement one or more receiving chains and transmitting chains. For example, UE106 may share one or more parts of a receiving chain and / or transmitting chain between multiple wireless communication technologies such as those discussed above.

[0111] In some embodiments, UE 106 may include independent (and possibly multiple) transmission chains and / or reception chains (e.g., including independent RF and / or digital radio components) for each wireless communication protocol configured to communicate with it. As another possibility, UE 106 may include one or more radio components shared between multiple wireless communication protocols, and one or more radio components used uniquely by a single wireless communication protocol. For example, UE 106 may include a shared radio component for communicating using any one of LTE, 1xRTT, and NR (or LTE or GSM), and an independent radio component for communicating using each of Wi-Fi and Bluetooth. Other configurations are also possible.

[0112] Figure 3 —Exemplary block diagram of UE

[0113] Figure 3An exemplary block diagram of a UE 106 according to one embodiment is shown. As shown, the UE 106 may include a system on chip (SOC) 300, which may include parts for various purposes. For example, as shown, the SOC 300 may include: one or more processors 302, which may execute program instructions for the UE 106; and a display circuit system 304, which may perform graphics processing and provide display signals to a display 360. The one or more processors 302 may also be coupled to a memory management unit (MMU) 340, which may be configured to receive addresses from the one or more processors 302 and convert those addresses into locations in a memory (e.g., a memory 306, a read-only memory (ROM) 350, a NAND flash memory 310), and / or coupled to other circuits or devices (such as a display circuit system 304, a wireless communication circuit system 330, a connector I / F 320, and / or a display 360). The MMU 340 may be configured to perform memory protection and page table conversion or setup. In some embodiments, the MMU 340 may be included as part of the processor 302.

[0114] As shown, SOC 300 may be coupled to various other circuits of UE 106. For example, UE 106 may include various types of memory (e.g., including NAND flash memory 310), connector interface 320 (e.g., for coupling to a computer system, taskbar, charging station), display 360, and wireless communication circuitry (e.g., radio component) 330 (e.g., for LTE, Wi-Fi, GPS, etc.).

[0115] The UE device 106 may include at least one antenna (and in various possibilities, multiple antennas, e.g., for MIMO and / or for implementing different wireless communication technologies) for performing wireless communications with base stations and / or other devices. For example, the UE device 106 may perform wireless communications using one or more antennas 335. As mentioned above, in some embodiments, the UE 106 may be configured to perform wireless communications using multiple wireless communication standards.

[0116] As described further herein later, UE 106 may include hardware and software components for implementing features related to using the time slot format indicator in different ways as described herein. The processor 302 of the UE device 106 may be configured to implement some or all of the methods described herein, for example, by executing program instructions stored on a memory medium (e.g., a non-transitory computer-readable memory medium). In other embodiments, the processor 302 may be configured as a programmable hardware element such as an FPGA (field programmable gate array) or as an ASIC (application-specific integrated circuit). Alternatively (or in addition), in combination with one or more of the other components 300, 304, 306, 310, 320, 330, 335, 340, 350, 360, the processor 302 of the UE device 106 may also be configured to implement some or all of the features described herein.

[0117] Figure 4 —Exemplary block diagram of a base station

[0118] Figure 4 An exemplary block diagram of a base station 102 according to one embodiment is shown. It should be noted that Figure 4 The base station of is only one example of a possible base station. As shown, the base station 102 may include a processor 404, which may execute program instructions for the base station 102. The processor 404 may also be coupled to a memory management unit (MMU) 440, which may be configured to receive addresses from the processor 404 and convert these addresses to locations in memory (e.g., memory 460 and read-only memory (ROM) 450)) or to couple to other circuits or devices.

[0119] Base station 102 may include at least one network port 470. Network port 470 may be configured to couple to a telephone network and provide access to the telephone network described above. Figure 1 and Figure 2 Multiple devices of the telephone network described in the figure, such as UE device 106.

[0120] The network port 470 (or an additional network port) may additionally or alternatively be configured to couple to a cellular network, such as a core network of a cellular service provider. The core network may provide mobility-related services and / or other services to multiple devices, such as the UE device 106. In some cases, the network port 470 may be coupled to a telephone network via the core network, and / or the core network may provide a telephone network (e.g., in other UE devices served by the cellular service provider).

[0121] The base station 102 may include at least one antenna 434 and possibly multiple antennas. The antenna 434 may be configured to operate as a wireless transceiver and may be further configured to communicate with the UE device 106 via the radio component 430. The antenna 434 communicates with the radio component 430 via a communication chain 432. The communication chain 432 may be a receive chain, a transmit chain, or both. The radio component 430 may be configured to communicate via various wireless telecommunication standards, including but not limited to NR, LTE, LTE-A, UMTS, CDMA2000, Wi-Fi, etc.

[0122] BS 102 may be configured to perform wireless communications using multiple wireless communication standards. In some cases, base station 102 may include multiple radio components, which may enable base station 102 to communicate according to multiple wireless communication technologies. For example, as one possibility, base station 102 may include an NR radio component for performing communications according to NR and a Wi-Fi radio component for performing communications according to Wi-Fi. In such cases, base station 102 may be able to operate as both an NR base station and a Wi-Fi access point. As another possibility, base station 102 may include a multi-mode radio component that can perform communications according to any of a variety of wireless communication technologies (e.g., NR and Wi-Fi, NR and LTE, LTE and CDMA2000, UMTS and GSM, etc.).

[0123] As described further later herein, BS 102 may include hardware and software components for implementing features related to using slot format indicators in various ways as described herein.

[0124] The processor 404 of the base station 102 may be configured to implement part or all of the methods described herein, for example, by executing program instructions stored on a memory medium (e.g., a non-transitory computer-readable memory medium). Alternatively, the processor 404 may be configured as a programmable hardware element such as an FPGA (field programmable gate array), or as an ASIC (application-specific integrated circuit) or a combination thereof. Alternatively (or in addition), in combination with one or more of the other components 430, 432, 434, 440, 450, 460, 470, the processor 404 of the BS 102 may also be configured to implement part or all of the features described herein.

[0125] Group common PDCCH

[0126] A group-common PDCCH is a channel that carries information intended for a group of user equipments (UEs).The modifier "common" does not necessarily mean common to every cell.

[0127] Potential use cases for group-common PDCCH include:

[0128] (1) Specify the time slot format (UL, DL, SL, blank, etc.) in dynamic TDD;

[0129] (2) Indicates the duration of control resource setup, in which case the UE can determine whether some blind decoding can be skipped;

[0130] (3) Indicates the starting position of the downlink data.

[0131] A PCFICH-like approach may be used to implement the physical channel structure of the group-common PDCCH. Alternatively, the PDCCH design may be reused.

[0132] The network (NW) may configure the UE to monitor the group-common PDCCH using RRC signaling. In other words, the network may send one or more RRC signals to the UE to indicate whether the UE is to decode the group-common PDCCH.

[0133] TDD configuration in LTE

[0134] In LTE Release 8, TDD configuration is defined to indicate the transmission direction in each time slot of a radio frame. (The duration of a radio frame may be 10ms). TDD configuration is semi-static configuration information and is signaled to the UE via a system information block of type 1 (denoted as SIB1). Seven different TDD configurations are defined, such as Figure 5A (Symbol D represents downlink; S represents a special subframe for switching from downlink to uplink; U represents uplink.)

[0135] Special Subframe (SSF)

[0136] like Figure 5B As shown, the special subframe consists of the following three parts: DwPTS, GP and UpPTS.

[0137] DwPTS is considered a normal downlink subframe that carries RS, control information, and data. (RS is the acronym for Reference Signal.)

[0138] GP is the guard period. The guard period is large enough to cover the round trip time (RTT) from the cell and the switching time at the UE. Figure 5B In , PT represents the propagation time and ST represents the switching time. The UE needs time to switch from reception to transmission. ) The length of the protection period determines the maximum cell size.

[0139] UpPTS may be used for uplink transmission of a sounding reference signal (SRS) or a random access channel (RACH).

[0140] While DwPTS, GP and UpPTS have lengths that increase the subframe length (in time), the combination of lengths can be configured between 9 formats. In other words, the vector (length DwPTS, length GP, length UpPTS) has nine possible states. Figure 5C is a table showing nine special subframe formats, where the cells correspond to OFDM symbols with 15 kHz subcarrier spacing. Figure 5D In a more graphical manner, nine special subframe formats are shown.

[0141] eIMTA in LTE Release 12

[0142] eIMTA is an acronym for “Enhanced Interference Mitigation and Traffic Adaptation.” In eIMTA, the configuration can be changed dynamically through downlink control information (DCI).

[0143] In eIMTA, the TDD configuration is determined as follows. The TDD frame structure is generated by combining the UL reference configuration and the DL reference configuration. An example of the UL reference configuration and the DL reference configuration is shown in Figure 6 Shown in. Figure 7 Shown by Figure 6 The example of the valid TDD frame structure generated by F represents the TTI of either downlink (D) or uplink (U). In eIMTA, only the time slots designated by F can be changed dynamically. Figure 7 The current configurations supported by the frame structure are 0, 1, 2, 3, 4, and 5.

[0144] The uplink reference configuration is semi-statically configured and obtained by the UE from SIB1. The uplink reference configuration is used by devices supporting non-eIMTA and is called "uplink-downlink configuration" in earlier releases (~R11). The uplink reference configuration is an uplink strong configuration. DL subframes in the uplink reference configuration are guaranteed to be DL: for example, used for transmission of PHICH.

[0145] The downlink reference configuration is semi-statically configured, obtained by the UE from dedicated RRC signaling, specific to devices supporting eIMTA. The UL subframes in this configuration are guaranteed to be UL: for example, for HARQ feedback.

[0146] The current uplink-downlink configuration determines which subframes of the current frame are uplink and which subframes are downlink. The current uplink-downlink configuration is selected from 7 possible configurations and is within the limits set by the flexible subframes obtained from the reference configuration. The current uplink-downlink configuration is broadcasted periodically to track traffic changes. The current uplink-downlink configuration is broadcasted to all eIMTA devices (using eIMTA-RNTI) using DCI format 1C on PDCCH.

[0147] Flexible slot format indicator in dynamic TDD

[0148] In LTE, a time slot can be a downlink time slot (D), an uplink time slot (U), a special frame time slot (S), or a flexible time slot (F). Figure 8 An example of a TDD frame structure including each time slot is shown. The symbol "S / D" indicates that the corresponding time slot may be either S or D.

[0149] In NR, the slot format indicator (SFI) indicates whether the slot is downlink (DL), uplink (UL), sidelink (SL), blank (reserved), etc. Figure 8 The Slot Format Indicator (SFI) in the initial part of the F slot is shown. The SFI may override the transmission direction indicated by the current TDD configuration of the frame. For example, if the current TDD configuration indicates that the F slot should be uplink, the SFI may override the transmission direction to downlink. Thus, the SFI provides dynamic override capability at the granularity of the slot.

[0150] In some implementations, the SFI may be included only in the F slot. In other implementations, the SFI may be included in any of the slots of the frame.

[0151] A slot format indicator (SFI) may be included in the group common PDCCH. The SFI may signal the slot format of at least the current slot in a dynamic TDD system. In some embodiments, the SFI may signal the slot format of one or more consecutive slots including the current slot.

[0152] SFI is common information delivered to a group of UEs. SFI may indicate whether a timeslot is UL, DL, SL, blank (reserved), etc.

[0153] The SFI may be decoded by a group of UEs, such as a group of UEs specified by RRC signaling.

[0154] In some implementations, non-serving UEs may use the received SFI to avoid unnecessary blind decoding in order to save power.

[0155] Table-based SFI encoding - SFI for UL

[0156] In some embodiments, the SFI may indicate Fig. 9 Any of the uplink center slot formats shown in . These slot formats differ in the aggregation level, e.g. the number of slots that are combined together to form a continuous uplink region. The main use case for these uplink center slot formats is PUSCH and / or PUCCH transmissions.

[0157] The UL center time slot may include a PDCCH for transmitting UL grants to the UE.

[0158] The UL aggregation level (AL) (eg, 1, 2, 3, ...) may be encoded in the SFI.

[0159] The SFI may signal UL slot aggregation and therefore, not including the PDCCH in any of the subsequent slots.

[0160] When UL slot aggregation is indicated, a non-served UE may sleep during the uplink portion of the first slot and all subsequent slots. (The UE will determine whether it is scheduled in the aggregated slot set based on the PDCCH of the first slot.) For example, when AL=3, the UE may sleep during the uplink portion of the first slot and the second and third slots.

[0161] Table-based SFI encoding - SFI for DL

[0162] In some embodiments, the SFI may indicate Fig.10 Any of the downlink-centric formats shown. These downlink-centric formats are used for the current slot, i.e., the slot containing the SFI. The SFI may be transmitted in every downlink slot. The main use case for these downlink-centric formats is PDSCH transmission with and without slot aggregation.

[0163] The SFI for DL ​​does not encode the aggregation level (AL) because the SFI may be sent in every DL slot and the DL aggregation is signaled to the UE in the downlink control information (DCI).

[0164] Some of the states of SFI for DL ​​indicate that PDCCH exists in the PDCCH region. Other states indicate that PDCCH does not exist.

[0165] Example of SFI and DL timeslot aggregation

[0166] Fig.11An example of slot aggregation is shown, where additional scheduling in the middle of the aggregation is allowed due to the PDCCH included in the PDCCH region of the second slot. (In some embodiments, the PDCCH region of each slot may span the first OFDM symbol of the slot). Two slots are aggregated. Some UEs are scheduled at aggregation level equal to 2. In addition, some UEs may be scheduled in the second slot due to the PDCCH in the second slot. Acknowledgements for DL ​​data transmissions are sent at the end of the second slot.

[0167] Fig.12 and Fig.13 An example of slot aggregation without additional scheduling in the middle of the aggregation is shown. Fig.12 An example of aggregating two time slots is shown; Fig.13 An example of aggregating three time slots is shown. All scheduled UEs are scheduled from the first time slot via the PDCCH of the first time slot. No UE is scheduled from the second time slot (or from any non-initial time slot), so there is no PDCCH in the second time slot. Non-scheduled UEs can avoid making blind decoding attempts when searching for PDCCH in the second time slot (or non-initial time slot).

[0168] SFI for DL ​​(alternative method)

[0169] Alternatively, the SFI for DL ​​may be defined based on the assumption that PDCCH regions are not allowed in aggregated non-initial slots. Fig.14A and Fig. 14B As shown, only the initial time slot includes a PDCCH region. (In some embodiments, the PDCCH region may span the first OFDM symbol of the time slot and include a group common PDCCH and a set of one or more PDCCHs.)

[0170] The SFI for DL ​​appears in the group common PDCCH of the PDCCH region of the initial slot, indicating the DL (centric) slot format of all aggregated slots (where AL>=1). The main use case is PDSCH transmission with and without slot aggregation. The SFI for DL ​​does indicate the aggregation level (AL), as the SFI can only be sent in the initial DL slot.

[0171] SFI for blank (reserved) / sidelink (SL)

[0172] In some embodiments, some of the states of the SFI are used to indicate empty time slots for forward compatibility, such as Fig.15As shown. During the blank region of the time slot, for example, during the complement of the resource elements containing the SFI (or containing the group common PDCCH), the base station does not transmit or receive signals understood by the legacy UE. Similarly, the legacy UE device can turn off the power of its transmitter and receiver during the blank region of the time slot. Base stations and UEs operating according to future standards (or future versions of the current standard) may transmit during this time slot, such as NR Phase II systems. The AL is encoded in the SFI. Therefore, multiple time slots can be aggregated to form a blank region that continuously covers more than one time slot.

[0173] In some embodiments, one or more of the states of the SFI are used to indicate that sidelink (SL) transmission is enabled, e.g. Fig.15 The format index is shown as 13. The sidelink transmission is a device-to-device transmission (eg, UE-to-UE, or vehicle-to-vehicle, etc.).

[0174] DL and UL combination

[0175] In some embodiments, some of the states of the SFI are used to indicate a combination of downlink and uplink transmissions covering two or more consecutive time slots. Fig.16 Two states of the SFI are shown, each indicating two slot combinations of downlink and uplink, with a DL to UL ratio of 1. Format index 14 indicates that the PDCCH is included in the PDCCH region. Format index 15 indicates that the PDCCH is not included in the PDCCH region.

[0176] Dynamic Time Division Duplex (TDD)

[0177] The SFI may be sent in time slots that support or allow dynamic changes in transmission direction. Fig.17 As shown, a time slot designated as a downlink time slot by the current TDD configuration can be dynamically changed to an uplink time slot by setting the SFI of the time slot to an appropriate value of the format index. This means that in at least some embodiments, the transmission direction of a time slot without an SFI cannot be changed.

[0178] If there is no SFI in a slot (eg, UL only), the transmission direction for that slot may be determined by the most recently transmitted SFI.

[0179] For base stations (e.g., gNBs), the dynamics and efficiency depend on how often the SFI is sent. For example, Fig.18 shows a very dynamic scene, while Fig.19 A less dynamic scene is shown.

[0180] SFI based on the generalized format

[0181] In some implementations, the slot format indicator (SFI) may indicate both the aggregation level and the number of symbols for all possible formats: downlink only, uplink centric, DL-UL combined. Fig. 20 As shown, the SFI may have five fields. Two of the fields define the length of the downlink region. Two of the fields define the length of the uplink region. One of the fields defines the length of the gap region between the downlink region and the uplink region. The boundaries between time slots do not need to occur at the time slot boundaries.

[0182] In some embodiments, it is assumed that the gap region occupies at most one entire time slot. Therefore, only a number of symbols are needed to specify the length of the gap region.

[0183] The downlink region appears after (eg, immediately following) the PDCCH region of the initial slot in the aggregated slot set. (The PDCCH region appears after Fig. 20 ) The gap region may be immediately followed by the downlink region. The uplink region may be immediately followed by the gap region.

[0184] In some embodiments, the SFI includes the following five fields:

[0185] The number of DL time slots N DL ;

[0186] No.(N DL +1) the number of DL symbols in a slot;

[0187] No.(N DL +1) The number of guard symbols in a time slot;

[0188] No.(N DL +1) the number of uplink symbols in a slot; and

[0189] Number of uplink time slots.

[0190] In an implementation where the UE knows the symbol length of each slot in advance, only two of the middle three numbers (from the above list) need to be included in the SFI. The present disclosure contemplates three implementations of the SFI corresponding to three possible ways of selecting two numbers from the middle three numbers.

[0191] Scheduling with SFI

[0192] In some embodiments, a base station (e.g., gNB) may semi-statically or dynamically signal timeslot aggregation.

[0193] In UL timeslot aggregation, for example Fig.21As shown, PDCCH is preferably not transmitted in the middle of the aggregation (e.g., in a non-initial time slot). (Transmitting PDCCH in a non-initial time slot should require insertion of a gap region to transition back to uplink transmission.)

[0194] In DL, PDCCH may be allowed in the middle of an aggregation, e.g. Fig. 22 As shown. The PDSCH for UE1 is scheduled in the first time slot and lasts until the end of the aggregated time slot (e.g., the second time slot). In the first option, a single PDCCH in the first time slot may indicate the PDSCH for UE1 in each time slot. In the second option, the PDCCH in each time slot independently schedules the PDSCH for UE1 in that time slot. The PDSCH for UE2 is scheduled only in the first time slot. The PDSCH for UE3 is scheduled only in the second time slot.

[0195] Rate Matching in the PDCCH Region

[0196] In some embodiments, when PDSCH is scheduled on multiple aggregated time slots, PDSCH is never mapped into the PDCCH region (or control resource set). In other words, elements of PDSCH are not allowed to be transmitted in the PDCCH region. Fig.23 and Fig.24 It should be noted that the light blue color representing the PDSCH for UE1 never appears in the PDCCH region (the first OFDM symbol) of any time slot.

[0197] In other embodiments, when the PDSCH is scheduled on multiple aggregated time slots, the PDSCH is not mapped into the PDCCH region (or control resource set), such as Fig.25 However, Fig.26 As shown, if no PDCCH is scheduled in a non-first time slot, the SFI in the non-first time slot can signal that there is no PDCCH in the PDCCH region of the non-first time slot, and the PDSCH for UE1 can be at least partially mapped to the PDCCH region of the non-first time slot to minimize the waste of time-frequency resources.

[0198] SFI for various time slot lengths

[0199] In some implementations, the same slot format indicator may be used in the context of a slot length of seven symbols and in the context of a slot length of 14 symbols.

[0200] for Fig. 27 As shown in the uplink (UL), the number of symbols and the gap length used for PDCCH are known. Therefore, the number of UL symbols can be calculated based on the following formula, for example:

[0201] The number of UL symbols = symbol length of a slot - slot length - PDCCH length.

[0202] for Fig.28 For the downlink (DL) shown, since the SFI indicates the number of UL symbols (if there is an uplink region in the time slot), it is easy to understand that the number of DL symbols for the DL (center) time slot is calculated based on the following formula, for example:

[0203] Number of DL symbols = symbol length of slot

[0204] -(Gap Length + UL Symbols)(UL Present = True)

[0205] In some embodiments, the SFI may be transmitted in the mini-slots to dynamically indicate the direction of each mini-slot containing the SFI.

[0206] Fig. 27 An exemplary format (eg, corresponding to Fig. 9 The format shown in 1-3). Fig.28 An exemplary format is shown in which an initial downlink portion is followed by a guard period and an uplink portion (eg, corresponding to Fig.10 5). In some embodiments, Fig.28 It may be used when the UE may receive data during the downlink portion and may transmit ACKs during the uplink portion.

[0207] In one set of embodiments, a method 2900 for operating a base station may include: Fig.29 The operations shown in .

[0208] At 2910, the method may include transmitting, by a radio component of a base station, a first slot format indicator (SFI) in a first slot of a radio frame. The first SFI may indicate a first transmission direction of at least a first portion of the first slot. The first transmission direction may be either an uplink transmission or a downlink transmission. The SFI may be included in a group common PDCCH of a PDCCH region of the first slot. The PDCCH region may span the first N symbol durations of the first slot, where N is greater than or equal to one.

[0209] In some embodiments, the integer N is equal to one.

[0210] The first SFI may indicate that the PDCCH region includes at least one PDCCH. Alternatively, the first SFI may indicate that the PDCCH region does not include a PDCCH, so the UE may save power by not attempting to decode (or search for) the PDCCH.

[0211] In some embodiments, the first SFI further indicates a second transmission direction of a second portion of the first time slot, wherein the second transmission direction is opposite to the first transmission direction. For example, the first portion may be a downlink portion and the second portion may be an uplink portion.

[0212] In some embodiments, the first SFI further indicates a second transmission direction of at least a portion of a second time slot, wherein the second time slot immediately follows the first time slot, wherein the second transmission direction is an opposite direction to the first transmission direction.

[0213] In some embodiments, when the first transmission direction is uplink transmission, the first SFI may indicate a timeslot aggregation level for the uplink transmission.

[0214] In some implementations, when the first transmission direction is downlink transmission, the range of timeslot aggregation for downlink transmission may be indicated in the DCI of the radio frame including the first timeslot.

[0215] In some embodiments, when the first transmission direction is a downlink transmission, the first SFI may indicate a timeslot aggregation level for the downlink transmission.

[0216] SFI can be divided into two parts (transmission direction and aggregation level) and encoded separately.

[0217] In some embodiments, the method may further include transmitting, by the radio component, a second SFI in a second time slot of the radio frame, wherein the second time slot immediately follows the first time slot. The second SFI may indicate a second transmission direction of at least a portion of the second time slot. The second transmission direction is either an uplink transmission or a downlink transmission. The second SFI may be included in a group common PDCCH of a PDCCH region of the second time slot.

[0218] In some embodiments, the second SFI may indicate that the PDCCH region of the second slot does not include a PDCCH.

[0219] In some embodiments, the method may further include transmitting, by a radio component of the base station, a second SFI in a second time slot of the radio frame, wherein the second SFI indicates that at least a portion of the second time slot is blank, wherein the second SFI is included in a group common PDCCH of a PDCCH region of the second time slot.

[0220] In some embodiments, the method may also include transmitting, by the radio component, a second SFI in a second time slot of the radio frame, wherein the second SFI indicates that at least a portion of the second time slot is to be used for a side link (such as UE to UE, or V2X), wherein the second SFI is included in a group common PDCCH in a PDCCH region of the second time slot.

[0221] In some implementations, a slot may be two or 7 or 14 symbols in length.

[0222] In one set of embodiments, a method 3000 for operating a user equipment (UE) device may include: Fig.30 The operations shown in .

[0223] At 3010, a radio component of a UE device may receive a first slot format indicator (SFI) from a first slot of a radio frame, wherein the first SFI indicates a first transmission direction of at least a first portion of the first slot, wherein the first transmission direction is either uplink or downlink. The SFI is included in a group common PDCCH of a PDCCH region of the first slot, wherein the PDCCH region spans a first N symbol duration of the first slot, wherein N is greater than or equal to one.

[0224] In some embodiments, the method may further include performing uplink transmission or downlink reception in the first portion of the first time slot based on the first transmission direction. In other words, if the first transmission direction is uplink, the UE radio component performs uplink transmission, and if the first transmission direction is downlink, performs downlink reception.

[0225] In some embodiments, the integer N is equal to one.

[0226] In some embodiments, the method may further include: in response to determining that the SFI indicates that the PDCCH region of the first time slot includes at least one PDCCH, decoding (or attempting to decode) a PDCCH from the PDCCH region.

[0227] In some embodiments, the method may further include: in response to determining that the SFI indicates that the PDCCH region does not include a PDCCH, omitting an attempt to decode PDCCH information from the PDCCH region.

[0228] In some embodiments, the method may also include: in response to determining that the first SFI indicates a second transmission direction of the second part of the first time slot, performing downlink reception or uplink transmission in the second part of the first time slot based on the second transmission direction, wherein the second transmission direction is a direction opposite to the first transmission direction.

[0229] In some embodiments, the first SFI further indicates a second transmission direction of at least a portion of a second time slot, wherein the second time slot immediately follows the first time slot, wherein the second transmission direction is an opposite direction to the first transmission direction.

[0230] In some embodiments, the first transmission direction is uplink transmission, wherein the first SFI indicates a timeslot aggregation level for uplink transmission.

[0231] In some embodiments, the first transmission direction is a downlink transmission, wherein the range of timeslot aggregation for downlink transmission is indicated in the DCI of the radio frame containing the first timeslot.

[0232] In some embodiments, the first transmission direction is a downlink transmission, wherein the first SFI indicates a timeslot aggregation level for the downlink transmission.

[0233] SFI can be divided into two parts (transmission direction and aggregation level) and encoded separately.

[0234] In some embodiments, the method may also include receiving, by a radio component of the UE device, a second SFI in a second time slot of the radio frame, wherein the second time slot immediately follows the first time slot, wherein the second SFI indicates a second transmission direction of at least a portion of the second time slot, wherein the second transmission direction is either an uplink transmission or a downlink transmission, and wherein the second SFI is included in a group common PDCCH of a PDCCH region of the second time slot.

[0235] In some embodiments, the method may further include: in response to determining that the second SFI indicates that the PDCCH region of the second time slot does not include a PDCCH, saving power by not attempting to decode PDCCH information from the PDCCH region of the second time slot.

[0236] In some embodiments, the method may also include: receiving, by a radio component of the UE device, a second SFI in a second time slot of the radio frame; and in response to determining that the second SFI indicates that at least a portion of the second time slot is blank, disabling uplink transmission or downlink reception in the at least a portion of the second time slot, wherein the second SFI is included in a group common PDCCH in a PDCCH region of the second time slot.

[0237] In some embodiments, the method may also include: receiving, by the radio component, a second SFI in a second time slot of the radio frame, performing sidelink transmission in the at least a portion of the second time slot in response to determining that the second SFI indicates that at least a portion is to be used for the side link, wherein the second SFI is included in a group common PDCCH of the PDCCH region of the second time slot.

[0238] In some embodiments, the length of a slot is two or 7 or 14 symbols.

[0239] Unified TDD solution design principles

[0240] In one set of implementation schemes, the TDD scheme may be designed to support NR and coexist with LTE. Therefore, the TDD scheme may be referred to as a "unified" TDD scheme. The unified TDD scheme may coexist with LTE-TDD, which includes LTE TDD R8-R11 (static TDD) and LTE TDD R12~ (eIMTA). (The symbol "~" here means "and subsequent versions.") Regarding traffic adaptation, the unified TDD scheme may support semi-static TDD configuration and dynamic TDD configuration.

[0241] Flexible approach

[0242] In the unified framework for NR, the semi-static TDD configuration can be semi-statically configured by the following information:

[0243] Period (milliseconds);

[0244] the length of the downlink portion (D); and

[0245] Length of the uplink portion (U).

[0246] See also Fig.31 . Within a period, the downlink portion occurs first and the uplink portion occurs last. The downlink length and uplink length may be specified at symbol resolution. Thus, the downlink length may be specified in terms of the number of complete time slots and the number of symbols relative to a reference number (e.g., 15kHz or 30kHz). Similarly, the uplink length may be specified in terms of the number of complete time slots and the number of symbols relative to a reference number.

[0247] Resources that occur within a period but not in the downlink part or the uplink part are considered flexible (F).

[0248] Flexible length = period (ms) - DL length (ms) - UL length (ms).

[0249] The resources in the flexible part may be dynamically configured by the scheduling process for downlink transmission, uplink transmission, or unknown transmission. Flexible resources that are still undetermined after scheduling may be considered as gaps (e.g., for DL ​​to UL switching). The minimum gap length (in terms of the number of slots and symbols relative to the reference number) may also be broadcast to all UEs.

[0250] NR TDD configuration for coexistence with LTE

[0251] Figure 32A-32C It is shown how the TDD configuration of the present unified framework can be made compatible with the TDD configuration of LTE. Fig.32A 1 shows the TDD configuration of LTE. Fig.32BAs shown, by applying a cyclic time shift of n units of time, the LTE TDD configuration identified by configuration index n can be converted to one or two cycles of the unified frame TDD configuration. (From the LTE perspective, the unit is a subframe. From the NR perspective, the unit is a time slot with a subcarrier spacing of 15kHz in this figure.) Fig.32C Shown from Fig.32B Observe that the gap (G) within the special subframe (S) can be realized by the flexible part (F) of the unified framework. Fig.33 , where the special subframe S is decomposed into x downlink symbols, y flexible symbols (for gaps) and z uplink symbols, where

[0252] The number of symbols per subframe = x + y + z.

[0253] Fig.33 Assume the subcarrier spacing (SCS) is 15kHz. For any subcarrier spacing (SCS), Fig.33 The length of the number can be scaled by a scaling factor = SCS / 15kHz. The notation (slot, symbol) is used to represent the length of a region (such as UL, DL or F), which is based on the number of slots N. Slot The number of sum symbols n Sym The length of this region corresponds to N Slot full time slots plus n Sym symbol.

[0254] When a NR base station (gNB) operates on a frequency channel adjacent to the frequency channel used by an LTE base station, the NR base station can provide harmonious coexistence with the LTE base station in the following ways:

[0255] Applying the time shift to the time slot of the TDD configuration of the unified framework to obtain the time slot of the TDD configuration of 3GPP LTE; and

[0256] Perform TDD operation based on the LTE TDD configuration. (In some embodiments, TDD operation is the act of controlling the selection of transmission or reception, or neither, over time.)

[0257] In some embodiments, the time shift may be a cyclic time shift of time slots. For example, if the TDD configuration CU of the unified framework has five time slots per cycle, and the cycle sequence under the CU is represented as

[0258] [ABCDE][ABCDE][ABCDE]…,

[0259] Then, the cyclic time shift to three slots forward (or two slots backward) within each cycle should give an LTE TDD configuration of the following form:

[0260] [CDEAB][CDEAB][CDEAB]….

[0261] In other embodiments, the time shift may be a non-cyclic time shift, as shown in the following expression:

[0262] Unification: [ABCDE][ABCDE][ABCDE]…,

[0263] LTE: [CDEAB][CDEAB][CDEAB]…,

[0264] The period of the LTE TDD configuration can be obtained by sampling from the periodic slot sequence of the unified framework, with an offset of two slots in time. Note that the period boundaries of LTE are offset relative to the period boundaries of the unified framework.

[0265] NR UEs can apply the same time shift (cyclic or non-cyclic) to the time slots of the TDD configuration of the unified framework and perform TDD operation based on the resulting LTE TDD configuration. When there is no frequency-adjacent LTE base station, the NR base station and NR UE do not need to perform the above time shift.

[0266] Matching special subframes to coexist with LTE

[0267] In order to provide coexistence of special slots under a unified framework with LTE 3GPP's Special Subframes (SSF), gap alignment may be provided as follows. The gNB may signal the gap length to all UEs via higher layer signaling. For the downlink, a downlink scheduled UE learns the end time of its data transmission from its DCI. The gap may start after (e.g., immediately following) the end of the downlink transmission. For the uplink, the UE may start UL transmission based on scheduling of an ACK message or based on being pre-configured for RACH, SRS, etc. See Fig.34 , which shows that the symbols of the NR time slot (under the unified framework) and the symbols of LTE SSF format=3 have been aligned.

[0268] Detailed usage of time slots

[0269] In some embodiments, the DL and UL transmission directions may be determined semi-statically. The detailed usage of the time slots may be determined by scheduling information. The parameters K0, K1, K2, K3 (or any subset thereof) may be indicated by downlink control information (DCI), for example, by user-specific DCI, where:

[0270] K0 is the time slot distance from DL grant to DL data;

[0271] K1 is the time slot distance from DL data to ACK;

[0272] K2 is the time slot distance from DL grant to UL data;

[0273] K3 is the time slot distance from UL data to ACK.

[0274] For example, Fig.35 As shown, assuming a period of 5 ms, the signal K0=0 from the left in the PDCCH of the first time slot indicates that DL resources (for transmission of DL data) are granted to the UE in the PDSCH of the first time slot. The PDSCH of the first time slot extends from symbol 1 to symbol 13. As another example, the signal K1=4 in the first time slot indicates that the uplink acknowledgment (ACK) of the DL data of the first time slot will occur in the fifth time slot, for example, in symbols 12 and 13 of the fifth time slot, where the first time slot is counted as time slot 0. As another example, the signal K2=2 in the PDCCH of the third time slot indicates that the third time slot contains a DL grant for uplink transmission resources in the fifth time slot. See the PUSCH in the fifth time slot, which extends from symbol 0 to symbol 11 of the fifth time slot.

[0275] NR TDD configuration (for non-coexistence scenarios)

[0276] When operating an NR cell alone (e.g., without frequency-adjacent LTE channels), the TDD configuration of the NR cell may be signaled to the UE semi-statically or dynamically, or a combination of semi-static and dynamic. The operator determines, for example, to configure the cell appropriately based on the distance to nearby cells, cell size, etc. When operating an NR cell in the presence of frequency-adjacent LTE channels, the NR node (base station or UE) needs to align (i.e. match) its transmission direction with the LTE TDD configuration used by the frequency-adjacent LTE channels. The NR base station may semi-statically signal the matching TDD configuration to the UE. However, the NR base station may also dynamically signal the matching TDD configuration.

[0277] In at least some embodiments, a configuration referred to as "dynamic" may refer to:

[0278] The configuration is conveyed via a physical layer signal (e.g., an L1 signal such as DCI);

[0279] The configuration may be changed frequently (eg, every time slot); and

[0280] The configuration is valid only for a short period of time (eg, one or a few time slots).

[0281] In contrast, semi-static configuration may be a configuration based on RRC signaling, which is a higher layer signaling. (RRC is an acronym for Radio Resource Control.) Higher layer signaling is expected to be sent infrequently, for example, on the order of a few hundred milliseconds. This means that the configuration is valid for a longer period of time until it is changed later.

[0282] Flexible slots (F) can be used to quickly adapt to traffic load.

[0283] For the flexible part of the semi-static TDD configuration, the transmission direction is dynamically determined through physical layer signaling such as DCI and / or SFI.

[0284] In some embodiments, the transmission direction indicated by the semi-static TDD configuration (or semi-static DL / UL allocation in specification terminology) may not contradict the transmission direction indicated by the dynamic DCI. In addition or alternatively, in a system configured with a semi-static TDD configuration (or semi-static DL / UL allocation) and SFI, the transmission direction indicated by the SFI may not contradict the transmission direction of the DCI.

[0285] In some embodiments, there are at least two options on how to resolve the contradictions in the transmission directions indicated by the semi-static configuration, SFI, and DCI.

[0286] Option (1): SFI has a higher priority than semi-static configuration, except for the transmission direction of fixed uplink resources and the transmission direction of fixed downlink resources. In addition, DCI has a higher priority than SFI. Finally, DCI has a higher priority than semi-static configuration.

[0287] Option (2): SFI has a higher priority than semi-static configuration, except for the transmission direction of fixed uplink resources and the transmission direction of fixed downlink resources. In addition, SFI has a higher priority than DCI.

[0288] Fig.36 Detailed usage of timeslots is shown how they may be determined by scheduling. At 3610, an example of a TDD configuration without scheduling is shown. The period is 5 ms; the subcarrier spacing is 15 kHz; the downlink has a length given by (0,12); the uplink has a length given by (0,12); the flexible part has a length given by (3,4). At 3620, detailed usage of scheduling is shown according to a number of examples.

[0289] Example 1: Independent downlink time slots can be scheduled. Fig.36 As shown, setting the parameter K1=0 in the DCI of the first time slot indicates that the confirmation of the downlink data of the first time slot will also be in the first time slot, for example, at the end of the first time slot.

[0290] Example 2: SFI and / or DCI may determine how to use flexible time slots. When K2=0, F is determined as UL to meet the needs of large UL traffic.

[0291] Example 3: DCI may schedule UL traffic in the UL portion of the frame structure.

[0292] Figure 37A-Figure 37E Examples are presented of how the flexible part of a frame structure with a single time slot may be specialized in different ways depending on the state of the SFI and / or DCI. Fig.37A The frame structure of a unified frame is shown, where period = 1 slot, the DL part has a length (0, 2), the UL part has a length (0, 2) and the flexible part has a length (0, 10). Fig.37B It is shown that the flexible part is defined as a combination of downlink transmissions and gaps by setting SFI=DL or by DCI signaling downlink transmissions. Fig.37C It is shown that the flexible part is defined as a combination of gaps and uplink transmissions by setting SFI=UL or by DCI signaling uplink transmissions. Fig.37D The flexible part is shown to be defined as "unknown" by setting the SFI equal to "unknown". (During the unknown part, the UE does not assume that the base station is transmitting or receiving.) Fig.37E Several consecutive cycles are shown, and it is shown how the flexible part of the semi-static TDD configuration changes dynamically in different cycles based on changes in the SFI and / or DCI status.

[0293] Period value

[0294] In different embodiments, different sets of values ​​are supported for the period. In some embodiments, at least periods of 10 ms and 5 ms are supported to provide coexistence with LTE. In other embodiments, a set of allowable periods includes at least 10 ms, 5 ms, 2 ms, and 1 ms. In other embodiments, a set of allowable periods includes at least 10 ms, 5 ms, 2 ms and 1 ms, 0.5 ms, 0.25 ms, 0.125 ms. (The last three values ​​can help provide support for URLLC. URLLC is an acronym for Ultra Reliable Low Latency Communications.) In other embodiments, support Fig.38 The cycle-SCS combination shown in .

[0295] Clearance and Cell Radius

[0296] Whenever a switch from downlink to uplink occurs, a gap is required. The size of this gap is equal to two one-way propagation delays plus the switching time:

[0297] Gap length = 2*propagation delay + switching time.

[0298] Furthermore, the cell radius is equal to the speed of light, C, multiplied by half the gap length:

[0299] C*gap length / 2=cell radius (assuming switching time=0).

[0300] For operation below 6 GHz, it may be advantageous to make the cell radius comparable to that in LTE. For operation above 6 GHz, the cell radius may be smaller than that of LTE. The gap size may be common to all UEs in a cell. The gap size may be semi-statically configured. It appears that the gap granularity of LTE's special subframe (SSF) is a bit coarse (as it is only defined based on SCS=15 kHz).

[0301] Gap length

[0302] In LTE, six different gap length values ​​are indirectly defined in the nine special subframe formats. (See Fig.39 )NR may also require smaller cell sizes to support high-frequency (e.g., greater than 6 GHz) operations. Fig.39 The table in shows a set of supported gap lengths for NR according to some embodiments. Note that the table includes gap lengths less than 0.0714 ms. The frequency (x KHz) appearing in the column headings is the subcarrier spacing.

[0303] Signaling

[0304] In some embodiments, the NR base station (i.e., gNB) may send a new semi-static TDD configuration in each period using an L1 signal such as DCI.

[0305] In some embodiments, the NR base station may send semi-static TDD configuration information multiple times to ensure that all UEs receive the information.

[0306] In some implementations, the semi-static TDD configuration information may include a time (eg, a radio frame number) when the new TDD configuration becomes effective.

[0307] In some embodiments, one or more dynamic signals may be used to provide dynamic TDD configuration of one or more time slots. The dynamic signal may be a slot format indicator (SFI) that indicates the type of one or more time slots from a set of allowed types. In one embodiment, the set of allowed types includes DL, UL, unknown, and empty.

[0308] In some embodiments, the dynamic signal may be a DCI. The DCI schedules data. The scheduling may be used for DL ​​transmission or UL transmission.

[0309] Unified framework for TDD configuration—fixed configuration method

[0310] In one set of embodiments, a fixed set of TDD configurations may be defined for NR, e.g. Figure 40-Figure 43 Specified in. The NR base station may transmit (e.g., broadcast) an index indicating which fixed TDD configurations to implement.

[0311] like Fig.40 As shown, the first subset of the set of fixed TDD configurations is designed to support coexistence with LTE. Specifically, each configuration of the first subset can be used to generate a corresponding TDD configuration for LTE by applying a corresponding time shift, with repetition in the case of the first three rows. Fig.40 The special subframe S in each configuration includes a flexible part that is consistent with the gap of the LTE special subframe.

[0312] Fig.41 and Fig.42 Fixed TDD configurations for NR are shown, with a subcarrier spacing of 15 kHz. Each of these configurations, except configuration 10, includes:

[0313] an initial portion having one or more consecutive time slots designated as downlink;

[0314] a terminating portion having one time slot designated as an uplink; and

[0315] The middle part is between the initial part and the final part.

[0316] The middle portion is designated as flexible. The detailed usage of the flexible time slots may be determined by dynamic physical layer configuration information such as SFI and / or DCI. Fig.41 Configurations 6 and 7 shown may be used to provide co-existence with LTE configurations by applying appropriate time shifts (with repetitions in the case of configuration 6) and appropriately specifying dynamic physical layer configuration information. Configuration 10 has a single time slot that is specified as flexible.

[0317] Fig.43 A fixed TDD configuration for NR with a subcarrier spacing of 30 kHz is shown.

[0318] Override semi-statically configured transfer direction

[0319] exist Fig.31 In a flexible manner, there are two options with respect to the possibility of overwriting the transmission direction in the downlink part (D) and / or the uplink part (U). In the first option, if Fig.44 As shown, overwriting is not allowed. In this option, the downlink part must be used as downlink and the uplink part must be used as uplink. The transmission direction or directions of the flexible part are determined later by dynamic physical layer configuration information. In the second option, as shown Fig.45 As shown, only non-fixed resources are allowed to be overwritten. The non-fixed downlink part appears in the end part of the downlink part. The non-fixed uplink part appears in the initial part of the uplink part.

[0320] In a fixed configuration, an override of one or more transmission directions may be supported by designating one or more consecutive time slots at the end of the downlink portion as non-fixed downlink, such as Fig.46 6 and 7. These non-fixed resources are overwritten by the transmission direction of the dynamic physical layer configuration information. Similarly, one or more consecutive time slots at the beginning of the uplink portion can be designated as non-fixed uplink, such as Fig.46 The configuration is shown in 6.

[0321] Methods for a flexible approach

[0322] In one set of embodiments, method 4700 for operating a user equipment device may include Fig.47 The operations shown in . (Method 4700 may also include the above and the following combination Figure 48-Figure 49 Any subset of the features, elements and embodiments described.)

[0323] At 4710, the radio component of the user equipment device may receive TDD configuration information, wherein the TDD configuration information includes parameters defining a semi-static TDD configuration for a frame structure. The parameters may include:

[0324] frame length, which specifies the duration of the frame structure;

[0325] a first length specifying a duration of a downlink portion of the frame structure, wherein the downlink portion occupies an initial position within the frame structure;

[0326] A second length specifies the duration of an uplink portion of the frame structure, wherein the uplink portion occupies a terminal position within the frame structure.

[0327] The middle part of the frame structure appears after the downlink part and before the uplink part, where the TDD structure of the middle part is not determined by the TDD configuration information. The TDD structure of a given time interval determines how the UE handles each symbol time of the time interval, for example, whether to transmit or receive or do nothing during the symbol time.

[0328] The radio component may include a baseband processor that performs the above method (or any other method described herein). The baseband processor may be coupled to the RF transceiver and configured to: (a) generate a baseband transmission signal that is converted by the RF transceiver into an RF transmission signal; and / or (b) operate on a baseband receive signal provided by the RF transceiver in response to an RF receive signal.

[0329] In some embodiments, method 4700 also includes, in response to receiving TDD configuration information, performing TDD operations, including: (a) receiving downlink data by the radio component from the downlink portion of the frame structure; and (b) transmitting uplink data by the radio component within the uplink portion of the frame structure.

[0330] In some embodiments, method 4700 also includes: receiving one or more physical layer signals (such as SFI and / or DCI) that dynamically determine the TDD structure of the middle portion; and performing TDD operations on the middle portion based on the dynamically determined TDD structure.

[0331] In some embodiments, the one or more physical layer signals include user-specific downlink control information (DCI) and a slot format indicator (SFI), wherein the slot format indicator is included in the group common PDCCH. If the transmission direction defined by the user-specific DCI for a given slot of the frame structure is inconsistent with the transmission direction defined by the SFI for the given slot, the radio component may perform TDD operation (e.g., transmission or reception) based on the user-specific DCI.

[0332] In some embodiments, one or more physical layer signals include downlink control information (DCI), wherein the DCI includes a first parameter that specifies a time slot distance between resource grant information and corresponding downlink data (e.g., downlink data occupying downlink resources identified by the resource grant information).

[0333] In some embodiments, the one or more physical layer signals include downlink control information (DCI), wherein the DCI includes a second parameter that specifies a time slot distance between downlink data and an uplink acknowledgment of the downlink data.

[0334] In some embodiments, one or more physical layer signals include downlink control information (DCI), wherein the DCI includes a third parameter that specifies a time slot distance between resource grant information and corresponding uplink data (e.g., uplink data occupying uplink resources identified by the resource grant information).

[0335] In some embodiments, the one or more physical layer signals include downlink control information (DCI), wherein the DCI includes a fourth parameter that specifies a time slot distance between uplink data and a downlink acknowledgment of the uplink data.

[0336] In some embodiments, the one or more physical layer signals include downlink control information (DCI) located in a time slot of the downlink portion of the frame structure.

[0337] In some embodiments, the one or more physical layer signals include downlink control information (DCI) located in a time slot in the middle portion.

[0338] In some embodiments, the one or more physical layer signals include a slot format indicator, wherein the slot format indicator is received by the radio from a group common PDDCH for a given slot of the frame structure. The slot format indicator may indicate a transmission direction for at least a portion of the given slot.

[0339] In some embodiments, method 4700 may further include performing TDD operation on each frame in the frame sequence based on a semi-static TDD configuration. For each of the frames in the sequence, the TDD structure of the middle portion of the frame may be determined by corresponding dynamic configuration information provided in one or more time slots of the frame.

[0340] In some embodiments, the downlink portion includes an initial subportion and a subsequent subportion, wherein the initial subportion is configured for downlink transmission without the possibility of dynamic overwrite to a different TDD state (e.g., downlink center, uplink, uplink center, blank, side link, etc.), and wherein the subsequent subportion is configured for downlink transmission and has the possibility of dynamic overwrite to a different TDD state.

[0341] In some embodiments, method 4700 may also include receiving a physical layer signal (such as an SFI and / or a DCI) indicating that at least a subset of subsequent sub-portions are to be overwritten to a TDD state other than the downlink transmission.

[0342] In some embodiments, the uplink portion includes a first subportion and a final subportion, wherein the first subportion is configured for uplink transmission and has the possibility of being dynamically overwritten to a different TDD state (e.g., downlink, downlink center, uplink center, blank, side link, etc.), and wherein the final subportion is configured for uplink transmission without the possibility of being dynamically overwritten to a different TDD state.

[0343] In some embodiments, method 4700 may further include receiving a physical layer signal indicating that at least a subset of the final sub-portions are to be overwritten to a TDD state except for uplink transmission.

[0344] In some embodiments, the downlink portion is configured for downlink transmission without the possibility of dynamic override to a TDD state different from downlink transmission, and the uplink portion is configured for uplink transmission without the possibility of dynamic override to a TDD state different from uplink transmission.

[0345] In some embodiments, the user equipment device receives TDD configuration information from a first base station operating on a first frequency channel, in which case the method 4700 may also include applying a time shift to a time slot of a current radio frame. The time shift may depend on an indicator of a TDD configuration used by a second base station, the second base station operating on a second frequency channel frequency adjacent to the first frequency channel. After the time shift, the current semi-static TDD configuration of the radio frame conforms to the TDD configuration of 3GPP LTE.

[0346] In some embodiments, the first length is specified based on a first number of complete time slots and a non-negative number x of symbols in the transition time slot, and the second length is specified based on a second number of complete time slots and a non-negative number z of symbols in the transition time slot. A symbol of a transition time slot that does not appear in any of the first x symbols of the transition time slot or the last z symbols of the transition time slot may be a gap symbol.

[0347] In some embodiments, the first number, the number x, the second number, and the number z are configured to be consistent with the TDD configuration of 3GPP LTE.

[0348] In some embodiments, the middle portion includes a gap region, where the length of the gap region is received by the UE through higher layer signaling.

[0349] In some embodiments, the middle portion includes a gap region, wherein the length of the gap region is less than 0.0714 ms.

[0350] In some implementations, the frame length corresponds to one time slot.

[0351] In some embodiments, the frame length indicates a time value from the set {10ms, 5ms, 2ms, 1ms, 0.5ms, 0.25ms, 0.125ms}.

[0352] In some embodiments, the TDD configuration information is included in a physical layer signal, such as downlink control information.

[0353] In some embodiments, multiple copies of the TDD configuration information are received. The base station transmits the multiple copies to increase the probability of successfully decoding the TDD configuration information.

[0354] In some embodiments, the TDD configuration information includes a time at which the radio is to start TDD operation using a semi-static TDD configuration.

[0355] Methods for fixing

[0356] In one set of embodiments, a method 4800 for operating a user equipment device may include: Fig.48The operations shown in . (Method 4800 may also include the above and the following combination Fig.49 Any subset of the features, elements and embodiments described.)

[0357] At 4810, a radio component of a user equipment device may receive a TDD configuration index, wherein the TDD configuration index has a value selected from a predefined set of values, wherein the values ​​of the predefined set identify corresponding semi-static TDD configurations, wherein a first subset of the values ​​of the predefined set identify semi-static TDD configurations that are consistent with corresponding TDD configurations of 3GPP LTE up to a time shift (cyclic or non-cyclic).

[0358] In some embodiments, method 4800 may also include, when the value of the TDD configuration index is in the first subset, performing a TDD operation based on a semi-static TDD configuration corresponding to the value, wherein performing the TDD operation includes applying a time shift to a time slot of the current frame, wherein the amount of the time shift depends on the value.

[0359] In some embodiments, the predefined set includes values ​​of a second subset that is disjoint from the first subset. For each value in the second subset, the corresponding semi-static TDD configuration may include:

[0360] an initial portion comprising one or more consecutive time slots for downlink transmission;

[0361] a termination portion comprising one or more consecutive time slots for uplink transmission; and

[0362] The middle part includes one or more continuous time slots, and the TDD structure of the continuous time slots will be dynamically determined by the physical layer configuration information.

[0363] In some embodiments, method 4800 may also include, in response to determining that the value of the TDD configuration index is in the second subset, performing TDD operations including: (a) receiving downlink data by the radio component from one or more symbols of the initial portion; and (b) transmitting uplink data by the radio component within one or more symbols of the termination portion.

[0364] In some embodiments, the physical layer configuration information includes downlink control information.

[0365] In some embodiments, the physical layer configuration information includes a slot format indicator that appears in the group-common PDDCH.

[0366] In some embodiments, the physical layer configuration information includes downlink control information (DCI) and a slot format indicator (SFI).

[0367] In some embodiments, the predefined set includes a third subset (e.g., disjoint with the first subset and the second subset), wherein for each value in the third subset, the corresponding semi-static TDD configuration includes only a single flexible time slot whose TDD structure is dynamically determined by physical layer configuration information.

[0368] In some embodiments, the predefined set includes a fourth subset, wherein for each value in the fourth subset, the corresponding semi-static TDD configuration includes, in chronological order:

[0369] a first portion comprising one or more consecutive time slots, wherein the first portion is allocated for downlink transmission without the possibility of dynamic overwriting to a TDD state other than downlink transmission; and

[0370] The second part includes one or more consecutive time slots, wherein the second part is allocated for downlink transmission and may be dynamically overwritten to a TDD state other than downlink transmission.

[0371] In some embodiments, for each value in the fourth subset, the corresponding semi-static TDD configuration further comprises, in chronological order:

[0372] a third portion comprising one or more consecutive time slots, wherein the third portion is allocated for uplink transmission and may be dynamically overwritten to a TDD state other than uplink transmission, wherein the third portion occurs after the second portion in time; and

[0373] A fourth portion includes one or more consecutive time slots, wherein the fourth portion is allocated for uplink transmission without the possibility of dynamically overwriting to a TDD state other than uplink transmission.

[0374] In some embodiments, the semi-static TDD configurations corresponding to the predetermined set of values ​​are divided into groups corresponding to respective subcarrier spacings.

[0375] In some embodiments, the semi-static TDD configurations corresponding to the predetermined set of values ​​are divided into sets corresponding to different time periodicities.

[0376] Dynamic TDD configuration via physical layer signaling

[0377] In one set of embodiments, method 4900 for operating a user equipment device may include Fig.49 (Method 4900 may include any subset of the above features, elements, and implementations.)

[0378] At 4910, a radio component of a user equipment device may receive physical layer configuration information from a first time slot of a plurality of time slots in a current frame, wherein the physical layer configuration information dynamically determines a TDD state (e.g., a transmission direction) of at least a portion of a designated time slot of the current frame, wherein the designated time slot is the first time slot in the current frame or a second time slot occurring after the first time slot.

[0379] In some embodiments, method 4900 may further include performing downlink reception or uplink transmission in the portion of the indicated time slot based on the dynamically determined TDD state.

[0380] In some embodiments, the physical layer configuration information includes a time slot format indicator, wherein the time slot format indicator is included in a group common PDCCH of the first time slot. In one embodiment, the method 4900 also includes receiving, by the radio component, downlink control information that allocates time-frequency resources in the at least a portion of the indicated time slot to the user equipment device, wherein the transmission direction indicated by the downlink control information is always consistent with the transmission direction indicated by the TDD state.

[0381] In some embodiments, the physical layer configuration information includes downlink control information (DCI). (For example, the DCI may be included in the PDCCH in the first time slot.)

[0382] In some embodiments, the DCI includes a parameter specifying a non-negative time slot distance between the first time slot and the indicated time slot.

[0383] In some embodiments, the parameter indicates that: resource grant information (eg, a grant of downlink resources) is included in a first time slot; and corresponding downlink data is included in the indicated time slot.

[0384] In some embodiments, the parameter indicates that downlink data (eg, PDSCH data) is included in a first time slot; and an uplink acknowledgement of the downlink data is included in the indicated time slot.

[0385] In some embodiments, the parameter indicates that: resource grant information (eg, a grant of uplink resources) is included in a first time slot; and corresponding uplink data is included in the indicated time slot.

[0386] In some embodiments, the parameter indicates that: the uplink data is included in a first time slot; and the downlink acknowledgment of the uplink data is included in the indicated time slot.

[0387] In some implementations, the TDD state determined by the physical layer configuration information overwrites the TDD state determined by previously received semi-static configuration information.

[0388] In some embodiments, the indicated time slot (or a portion thereof) was previously configured by previously received semi-static configuration information to be flexible in its transmission direction.

[0389] In some embodiments, the TDD state is selected from a set of TDD states including uplink transmission and downlink transmission.

[0390] In some embodiments, the set of TDD states also includes: uplink center transmission; downlink center transmission; side link transmission; and reserved for future use.

[0391] Slot format indicator

[0392] In one set of embodiments, a slot format indicator (SFI) is information that signals the slot format of one or more time slots. The SFI may describe how the resources are used. For example, the SFI may indicate that the time slot is used to send downlink signals, or indicate that the upcoming three time slots are used for DL, DL, and UL, respectively.

[0393] SFI and periodic signals

[0394] In some embodiments, SFI may be used primarily for non-scheduled UEs. Unlike scheduled UEs, which by definition have received DCI, non-scheduled UEs do not have DCI. Therefore, non-scheduled UEs cannot determine the transmission direction of the current time slot. (The transmission direction may have been changed by a DCI addressed to another UE, which the non-scheduled UE should not normally receive.) If there are any periodic signals (such as CSI-RS or SRS or CSI reports) configured for non-scheduled UEs in the current time slot, the non-scheduled UE should first know the transmission direction of the current time slot to determine (for example) whether to receive CSI-RS or transmit SRS. In this case, it is assumed that the transmission direction of the resources in which the periodic signal is configured can be changed. If this is not the case, for example, if a periodic signal is always transmitted in a fixed resource that does not allow the transmission direction to change, there may be no clear case where SFI is beneficial to non-scheduled UEs. From a resource utilization perspective, it may be too strict not to allow the transmission direction of such resources to be changed in the case of scheduled periodic signals.

[0395] In some embodiments, NR allows changing the transmission direction of resources where periodic signals such as CSI-RS or SRS are configured. The change of transmission direction can be achieved through dynamic L1 signaling. UE, especially non-scheduled UE, can receive dynamic L1 signaling to determine the transmission direction of resources.

[0396] Issues to consider in SFI design

[0397] There are two important cases that may need to be considered when defining SFI:

[0398] NR coexistence with LTE in adjacent channels; and

[0399] NR only (no co-existence with LTE).

[0400] In the second case (NR only case), the design of SFI is not too restrictive. However, in the first case, the LTE TDD configuration should be considered when designing SFI, because if NR does not provide UL / DL transmission direction configuration matching LTE, they (e.g., NR's gNB and LTE's eNB) can potentially introduce cross-link interference (CLI) to each other, thereby degrading the performance of both RATs. (Cross-link interference should occur when the NR cell and the LTE cell transmit in opposite directions at the same time, for example, when the NR cell is receiving / transmitting and the LTE cell is transmitting / receiving.)

[0401] Another important factor affecting the design of SFI is the UL / DL transmission direction allocation mode. It has been agreed that NR should support both semi-static and dynamic allocation of UL / DL transmission directions. In the case of semi-static allocation, in at least some embodiments, SFI can be similar to the static LTE-TDD configuration defined in Release 8 LTE. In the case of dynamic TDD, SFI can be similar to the dynamic TDD configuration defined in R12 eIMTA. The different modes of UL / DL transmission direction allocation are discussed in the section entitled "UL / DL transmission direction allocation for NR".

[0402] Resource Type

[0403] In some implementations, the following five different types of resources may be defined for NR:

[0404] (1) DL: resources with downlink transmission direction;

[0405] (2) UL: resources with uplink transmission direction;

[0406] (3) Flexible: resources whose transmission direction is later determined by other signals;

[0407] (4) Reserved: Resources that the UE is not allowed to transmit or receive. The reserved status of the resources cannot be overwritten by other signals.

[0408] (5) Gap: Resources used for DL ​​to UL transition.

[0409] The network may signal the above five different types of resources to the UE via different types of signaling methods (eg, RRC, SFI or DCI). Note that there may be one or more types of resources in a given time slot.

[0410] UL / DL transmission direction allocation for NR

[0411] Semi-static UL / DL allocation

[0412] In some embodiments, the network may support semi-static allocation of UL / DL transmission direction configurations. In semi-static allocation, the UL / DL transmission direction is semi-statically configured by RRC signaling and rarely changes. This semi-static setup is preferred when the network has neighboring cells that are close to each other. In this case, if two neighboring gNBs perform scheduling without knowing each other's transmission direction, neighboring cells transmitting in different directions may introduce significant cross-link interference (CLI).

[0413] Configuration cycle

[0414] In one set of embodiments, the gNB and UE are designed to support periodicities including 0.5ms, 1ms, 2ms, 5ms, 10ms for semi-static allocations. (In at least some of these embodiments, the supported periodicities also include about 0.125ms and about 0.25ms.) This means that a set of configurations corresponding to supported periodicities needs to be defined. Various periodicities with different subcarrier spacings or different slot durations may be used. 10ms and 5ms may be necessary for NR to generate UL / DL transmission direction allocations that match those of LTE. Shorter periods such as 0.5ms, 1ms, and 2ms may be used for larger subcarrier spacings with shorter DL to UL round trip times.

[0415] Configuration structure

[0416] In at least some embodiments, a single cycle may have both a DL transmission portion and a UL transmission portion with a gap in between.A set of configurations may have various patterns with different ratios of time lengths for the DL, gaps, and UL. Fig.50 Three different examples of configurations with different UL:DL ratios are shown.

[0417] Transmission direction alignment

[0418] In semi-static allocation, there are two types of signals indicating the transmission direction: RRC signals for semi-static allocation; and DCI. RRC signals are used to configure semi-static allocations, and DCI is used to schedule PDSCH / PUSCH. In some embodiments, the transmission direction indicated by RRC and the transmission direction indicated by DCI should be aligned, that is, consistent with each other. That is, there should be no contradiction between them in semi-static allocation. From the UE's perspective, this means that the UE can assume that the transmission direction indicated by RRC signaling always matches the transmission direction in DCI (if any).

[0419] Therefore, in some implementations of semi-static allocation, the transmission direction indicated by the RRC signaling should be aligned with the transmission direction in the DCI.

[0420] Unified approach

[0421] The role of UL / DL configuration may be similar to that of SFI. There are subtle differences in context. The term "UL / DL transmission direction assignment" is often used when referring to a long-term persistent configuration in the context of semi-static assignment, while the term "SFI" is used when referring to a shorter-lived configuration in the context of dynamic TDD. However, there may be no need to use two different terms, and they can be unified into a single framework.

[0422] In some implementations, a subset of slot formats supported by the SFI may be defined as UL / DL configurations for semi-static cases.

[0423] Dynamic Allocation

[0424] Framework for dynamic UL / DL allocation

[0425] In some embodiments, a framework for NR dynamic UL / DL allocation based on periodic monitoring of dynamically changing SFIs may be envisioned, where the monitoring period may be semi-statically configured. According to one embodiment, the SFI transmitted at the beginning of a cycle indicates at least the slot format of all slots belonging to the cycle.

[0426] Therefore, in some implementations, for dynamic UL / DL transmission direction allocation, one or more of the following may be proposed:

[0427] (a) The UE is configured to periodically monitor the SFI;

[0428] (b) The network can send SFI in the first time slot of each cycle;

[0429] (c) the SFI transmitted in the current cycle indicates the time slot format of at least the time slots in the current cycle;

[0430] (d) The monitoring period may be configured, for example, via RRC signaling;.

[0431] (e) If the UE fails to receive an SFI and does not send a DCI, the UE may simply use one or more slot formats defined by the most recently received SFI;

[0432] (f) Alternatively, if the UE fails to receive SFI and does not send DCI, the UE may regard the current cycle as reserved or flexible.

[0433] SFI transfer cycle

[0434] Note that the period determines how quickly the network can adapt to time-varying traffic demands in dynamic situations. The shorter the period, the faster it adapts. To make NR comparable to LTE eIMTA, it is necessary to support at least 5ms and 10ms period. To support even higher adaptability, 1ms may be supported, which corresponds to one time slot at a subcarrier spacing of 15kHz. In some embodiments, the period may be configurable via RRC signaling.

[0435] In some embodiments, for dynamic UL / DL transmission direction configuration:

[0436] NR supports a set of SFI transmission periods; and

[0437] NR supports at least 1ms, 5ms and 10ms periods.

[0438] Override transfer direction

[0439] There may be at least two options regarding overwrite capability. The first option is that the DCI cannot overwrite the SFI. In this case, the transmission direction indicated by the DCI should always match the transmission direction indicated by the SFI. The second option is to allow the DCI to overwrite the SFI. The second approach provides more dynamic operation. The rest of this section may refer to the second option.

[0440] In some embodiments, there may be a working assumption (WA) that the network may override the flexible resources indicated in the SFI via DCI. One motivation for this WA is to provide more flexibility in resource usage. When the network sends an SFI covering, for example, the upcoming 5 slots, the SFI may indicate some slots as flexible. These flexible slots may be overwritten by the DCI later as DL or UL. If they are not overwritten, the flexible slots may be considered as reserved resources.

[0441] One issue to consider is the protection of periodic signals, such as CSI-RS or SRS or CSI reports. Assume that a periodic signal is configured in a set of time slots, and one of these time slots is indicated as flexible by the SFI. In this case, if not all symbols of the time slot are configured to support periodic signals, the remaining symbols of the time slot can be used for uplink and / or downlink data transmission. The flexible state of this remaining resource can be overwritten by the DCI as uplink or downlink. Therefore, it is up to the network to determine whether it can protect the transmission / reception of the periodic signal. In this way, the network can utilize flexible resources while protecting the periodic signal.

[0442] Fig.51A and Fig.51B An implementation is shown in which the DCI overrides the transmission direction indicated by the SFI in time slot n+3 while protecting the configured periodic signal.

[0443] In some embodiments, for dynamic UL / DL allocation, the DCI may be configured to override one or more resources indicated by the SFI as flexible as either DL or UL.

[0444] In some embodiments, the NR should also support a mechanism for changing the transmission direction of resources configured for periodic signal transmission / reception. This can again be achieved using SFI. If the UE finds that (a) the transmission direction (either DL or UL) indicated by the SFI for the resources configured with periodic signals is different from (b) the transmission direction of the periodic signal, the UE should stop receiving / sending the periodic signal.

[0445] In some embodiments, for dynamic UL / DL allocation: If the SFI indicates a change in the transmission direction of the resource configured for the periodic signal, the periodic signal is cancelled. That is, the UE that is expected to transmit / receive the periodic signal in the resource should cancel the transmission / reception of the periodic signal in the resource.

[0446] The next question is whether DCI is allowed to change the transmission direction of resources indicated by SFI as DL or UL. In this case, changing the transmission direction can be avoided because it means that the UE cannot identify the transmission direction from SFI alone. That is, a non-scheduled UE cannot assume that the transmission direction is the same as indicated by SFI because DCI may change it. This is problematic, especially when periodic signals are configured.

[0447] In some embodiments, for dynamic UL / DL allocation, the DCI cannot change the transmission direction of resources indicated as DL or UL by the SFI.

[0448] Mixed Allocation

[0449] In some embodiments, the network may support hybrid allocation. Hybrid allocation may involve semi-static allocation and an overwrite mechanism using SFI or DCI. Therefore, there may be three different pieces of information, each of which indicates the direction of transmission. In some embodiments, regardless of the relative time at which the UE receives the SFI and DCI, the SFI and DCI should be aligned in the direction of transmission. Therefore, in at least some embodiments, if the DCI and SFI are valid information in time slot N, the transmission direction indicated by the DCI should match the transmission direction indicated by the SFI. This matching condition may be required because the SFI is mainly used for non-scheduled UEs, and the network should provide correct information to non-scheduled UEs.

[0450] In some embodiments, for mixed UL / DL allocations, the network may allow the transmission direction configured by the SFI and / or DCI to be overwritten by the RRC. In this case, the SFI and DCI should indicate the same transmission direction.

[0451] In one set of embodiments, a method 5200 for operating a user equipment device may include: Fig.52 The operations shown in . (Method 5200 may also include the above and the following combination Figure 53-Figure 60 Any subset of the features, elements and embodiments described.)

[0452] At 5210, a radio component of a user equipment device may receive dynamic physical layer configuration information, wherein the dynamic physical layer configuration information indicates a change in a transmission direction of a first resource within a given time slot of a current frame, wherein the first resource was previously configured for transmission or reception of a periodic signal.

[0453] At 5220, the radio component may perform reception or transmission of a periodic signal according to the changed transmission direction.

[0454] In some implementations, the periodic signal is a channel state information reference signal (CSI-RS), a sounding reference signal (SRS), or a CSI report.

[0455] In some implementations, the CSI-RS is a zero power CSI-RS (ZP CSI-RS) or a non-zero power CSI-RS (NZP CSI-RS).

[0456] In some embodiments, the dynamic physical layer configuration information is a slot format indicator included in a group common PDCCH for a given slot of a current frame or a previous slot.

[0457] In some embodiments, the dynamic physical layer configuration information is downlink control information (DCI).

[0458] In one set of embodiments, a method 5300 for operating a base station may include: Fig.53 The operations shown in . (Method 5300 may also include the above and the following combination Figure 54-Figure 60 Any subset of the features, elements and embodiments described.)

[0459] At 5310, a transmitter of the base station may transmit RRC signaling to the user equipment device, wherein the RRC signaling indicates a semi-static allocation of a first transmission direction corresponding to one or more time slots of the cycle, wherein the first transmission direction is either uplink or downlink.

[0460] At 5320, the transmitter (or a processor coupled to the transmitter) may generate downlink control information indicating the allocation of time-frequency resources to one or more user equipment devices, wherein while the semi-static allocation continues, the downlink control information is generated such that whenever the time-frequency resources appear in one or more time slots, the transmission direction indicated by the downlink control information for the time-frequency resources is consistent with the first transmission direction.

[0461] At 5330, the transmitter may transmit downlink control information.

[0462] In one set of embodiments, a method 5400 for operating a user equipment device may include: Fig.54 The operations shown in . (Method 5400 may also include the above and the following combination Figure 55-Figure 60 Any subset of the features, elements and embodiments described.)

[0463] At 5410, a radio component of a user equipment device may receive a slot format indicator (SFI) from a group common PDCCH, wherein the SFI has a value selected from a predefined set of values, wherein the values ​​of the predefined set identify corresponding TDD configurations, wherein a first subset of the values ​​of the predefined set corresponds to semi-static TDD configurations, and wherein a second subset of the values ​​of the predefined set corresponds to dynamic TDD configurations.

[0464] At 5420 , in response to determining that the SFI is equal to a given value in the first subset, the radio component may repeatedly perform TDD operations according to the corresponding semi-static TDD configuration.

[0465] In one set of embodiments, a method 5500 for operating a user equipment device may include: Fig.55 The operations shown in . (Method 5500 may also include the above and the following combination Figure 56-Figure 60 Any subset of the features, elements and embodiments described.)

[0466] At 5510, the radio component of the user equipment device may periodically monitor for the presence of a slot format indicator (SFI) according to a configured monitoring period.

[0467] At 5520, in response to detecting the presence of an SFI in the current cycle, the radio component may perform TDD operations according to the dynamic allocation of one or more transmission directions indicated by the SFI for one or more time slots of the current cycle.

[0468] In some embodiments, method 5500 may also include: in response to (a) failing to detect the SFI in the second period and (b) determining that downlink control information (DCI) for a given time slot has not been sent by the serving base station, the radio component performs transmission or reception in the given time slot based on the transmission direction indicated by the previously received SFI.

[0469] In some embodiments, method 5500 may also include disabling transmission and reception by the radio component during a given time slot in response to (a) detecting an SFI in a second period and (b) determining that downlink control information (DCI) for a given time slot is not sent by a serving base station.

[0470] In one set of embodiments, a method 5600 for operating a base station may include: Fig.56 The operations shown in . (Method 5600 may also include the above and the following combination Figure 57-Figure 60 Any subset of the features, elements and embodiments described.)

[0471] At 5610, the radio component of the base station may periodically transmit a time slot format indicator according to a transmission period, wherein each transmission of the time slot format indicator indicates that one or more transmission directions are dynamically allocated correspondingly in one or more time slots in a corresponding frame having a length equal to the transmission period.

[0472] At 5620, for a current frame corresponding to a current transmission of a slot format indicator, the radio component may perform TDD operation on one or more slots of the current frame based on the dynamic allocation indicated by the current transmission of the slot format indicator.

[0473] In some embodiments, the transmission period is selected from a group consisting of at least 1 ms, 5 ms, and 10 ms.

[0474] In some embodiments, method 5600 may also include: for a next frame corresponding to a next transmission of the time slot format indicator, performing TDD operations on one or more time slots of the next frame based on the dynamic allocation indicated by the next transmission of the time slot format indicator, wherein the dynamic allocation indicated by the next transmission of the time slot format indicator is different from the dynamic allocation indicated by the current transmission of the time slot format indicator.

[0475] In one set of embodiments, a method 5700 for operating a user equipment device may include: Fig.57 The operations shown in . (Method 5700 may also include the above and the following combination Figure 58-Figure 60 Any subset of the features, elements and embodiments described.)

[0476] At 5710, a radio component of a user equipment device may receive downlink control information that allocates a time-frequency resource set to the user equipment device and indicates a transmission direction of the time-frequency resource set, wherein the indicated transmission direction overrides a flexible state indicated by a previously received time slot format indicator for the time-frequency resource set.

[0477] At 5720, the radio component may perform transmission or reception in the set of time-frequency resources according to the indicated transmission direction.

[0478] In some embodiments, the set of time-frequency resources is a PDSCH for a user equipment device, where the indicated transmission direction is downlink.

[0479] In some embodiments, the set of time-frequency resources is a PUSCH for a user equipment device, where the indicated transmission direction is uplink.

[0480] In one set of embodiments, a method 5800 for operating a user equipment device may include: Fig.58 The operations shown in . (Method 5800 may also include the above and the following combination Figure 59-Figure 60 Any subset of the features, elements and embodiments described.)

[0481] At 5810, a radio component of a user equipment device may receive a slot format indicator (SFI) from a first slot of a current frame comprising one or more slots, wherein the SFI indicates a dynamically allocated transmission direction of a first time-frequency resource that has been previously configured for transmitting or receiving a periodic signal.

[0482] At 5820, in response to determining that the indicated transmission direction is inconsistent with the transmission direction of the periodic signal, the radio component may cancel the periodic signal for at least the current frame.

[0483] In some embodiments, the periodic signal is a channel state information reference signal (CSI-RS), wherein canceling the periodic signal includes not receiving the CSI-RS.

[0484] In some implementations, the CSI-RS is a zero power CSI-RS (ZP CSI-RS) or a non-zero power CSI-RS (NZP CSI-RS).

[0485] In some embodiments, the periodic signal is a sounding reference signal (SRS) or a CSI report, wherein the canceling of the periodic signal includes not transmitting the sounding reference signal or the CSI report.

[0486] In one set of embodiments, a method 5900 for operating a base station may include: Fig.59 The operations shown in . (Method 5900 may also include the above and the following combination Fig.60 Any subset of the features, elements and embodiments described.)

[0487] At 5910, a transmitter of the base station may transmit a slot format indicator in a current frame, wherein the slot format indicator indicates a transmission direction of at least a portion of an indicated slot of the current frame, wherein the indicated transmission direction is either downlink or uplink.

[0488] At 5920, the transmitter (or a processor coupled to the transmitter) may generate downlink control information to allocate time-frequency resources to a user equipment device, wherein the downlink control information is generated so that whenever the time-frequency resources appear within at least a portion of the indicated time slot, the transmission direction indicated by the downlink control information for the time-frequency resources is ensured to be consistent with the transmission direction indicated by the time slot format indicator.

[0489] At 5930, the transmitter may transmit downlink control information to the user equipment device.

[0490] In some embodiments, the slot format indicator is included in the group-common PDCCH of the first slot of the current frame.

[0491] In some embodiments, the time slot format indicator also indicates a flexible state of another part of the current frame, wherein the other part does not intersect with the at least a part of the indicated time slot, and the method further includes: generating additional downlink control information, which allocates time-frequency resources within the other part of the current frame to a user equipment device or another user equipment device, wherein the downlink control information is generated so that the transmission direction indicated by the downlink control information for the other time-frequency resource is (a) either downlink or uplink, and (b) overwrites the flexible state of the other time-frequency resource; and transmitting the additional downlink control information.

[0492] In some embodiments, the method may also include transmitting another time slot format indicator in the next frame, wherein the other time slot format indicator indicates a flexible state of a portion of the next frame, and the method further includes: generating additional downlink control information, which allocates time-frequency resources in the next frame to a user equipment device or another user equipment device, wherein the additional downlink control information is generated so that the transmission direction indicated by the downlink control information for the time-frequency resources in the next frame is (a) either downlink or uplink, and (b) overwrites the flexible state of the time-frequency resources in the next frame; and transmitting the additional downlink control information.

[0493] In one set of embodiments, a method 6000 for operating a user equipment device may include: Fig.60(Method 6000 may include any subset of the above features, elements, and implementations.)

[0494] At 6010, a radio component of a user equipment device may receive RRC signaling indicating a semi-static assignment of a transmission direction for a given timeslot in a cycle comprising one or more timeslots.

[0495] At 6020, the radio component may receive physical layer signaling indicating a dynamic assignment of a transmission direction for at least a portion of a given time slot in a current frame conforming to the cycle, wherein the dynamically assigned transmission direction is inconsistent with the semi-statically assigned transmission direction.

[0496] At 6030, the radio component may perform transmission or reception in the at least a portion of the given time slot according to the dynamically assigned transmission direction.

[0497] In some embodiments, the physical layer signaling includes a slot format indicator and / or downlink control information.

[0498] In some embodiments, the physical layer signaling includes downlink control information.

[0499] In some embodiments, whenever the physical layer signaling includes both a slot format indicator and downlink control information, the slot format indicator and the downlink control information coincide in the direction of transmission indicated for the at least a portion of a given slot.

[0500] Exemplary embodiments

[0501] In the following, further exemplary embodiments are provided.

[0502] A set of embodiments may include a method for operating a user equipment device, the method comprising: receiving TDD configuration information by a radio component of the user equipment device, wherein the TDD configuration information includes parameters defining a semi-static TDD configuration for a frame structure, wherein the parameters include: a frame length specifying the duration of the frame structure; a first length specifying the duration of a downlink portion of the frame structure, wherein the downlink portion occupies an initial position within the frame structure; and a second length specifying the duration of an uplink portion of the frame structure, wherein the uplink portion occupies a terminal position within the frame structure; wherein a middle portion of the frame structure appears after the downlink portion and before the uplink portion, wherein the TDD structure of the middle portion is not determined by the TDD configuration information.

[0503] In some embodiments, the method further includes: in response to receiving the TDD configuration information, performing TDD operations, including: receiving downlink data from the downlink portion of the frame structure by the radio component; and transmitting uplink data in the uplink portion of the frame structure by the radio component.

[0504] In some embodiments, the method further includes: receiving one or more physical layer signals that dynamically determine a TDD structure of the middle portion; and performing TDD operations on the middle portion based on the dynamically determined TDD structure.

[0505] In some embodiments, one or more physical layer signals include user-specific downlink control information (DCI) and a slot format indicator (SFI), wherein the slot format indicator is included in a group common PDCCH, wherein if the transmission direction defined by the user-specific DCI for a given time slot of the frame structure is inconsistent with the transmission direction defined by the SFI for the given time slot, the radio component performs TDD operation based on the user-specific DCI.

[0506] In some embodiments, the one or more physical layer signals include downlink control information (DCI), wherein the DCI includes a first parameter that specifies a time slot distance between resource grant information and corresponding downlink data.

[0507] In some embodiments, the one or more physical layer signals include downlink control information (DCI), wherein the DCI includes a second parameter that specifies a time slot distance between downlink data and an uplink acknowledgment of the downlink data.

[0508] In some embodiments, wherein the one or more physical layer signals include downlink control information (DCI), wherein the DCI includes a third parameter that specifies a time slot distance between the resource grant information and the corresponding uplink data.

[0509] In some embodiments, the one or more physical layer signals include downlink control information (DCI), wherein the DCI includes a fourth parameter that specifies a time slot distance between uplink data and a downlink acknowledgment of the uplink data.

[0510] In some embodiments, the one or more physical layer signals include downlink control information (DCI) located in a time slot of the downlink portion of the frame structure.

[0511] In some embodiments, the one or more physical layer signals include downlink control information (DCI) located in a time slot in the middle portion.

[0512] In some embodiments, the one or more physical layer signals include a slot format indicator received by the radio from a group common PDDCH for a given slot of the frame structure, wherein the slot format indicator indicates a transmission direction for at least a portion of the given slot.

[0513] In some embodiments, the method further includes: performing TDD operation on each frame in a frame sequence based on a semi-static TDD configuration, wherein for each of the frames in the sequence, the TDD structure of the middle part of the frame is determined by corresponding dynamic configuration information provided in one or more time slots of the frame.

[0514] In some embodiments, the downlink portion includes an initial subportion and a subsequent subportion, wherein the initial subportion is configured for downlink transmission without the possibility of dynamic overwrite to a different TDD state; and wherein the subsequent subportion is configured for downlink transmission and has the possibility of dynamic overwrite to a different TDD state.

[0515] In some embodiments, the method further includes receiving a physical layer signal indicating that at least a subset of subsequent sub-portions are to be overwritten to a TDD state except for the downlink transmission.

[0516] In some embodiments, the uplink portion includes a first subportion and a final subportion, wherein the first subportion is configured for uplink transmission and has the possibility of being dynamically overwritten to a different TDD state, and wherein the final subportion is configured for uplink transmission without the possibility of being dynamically overwritten to a different TDD state.

[0517] In some embodiments, the method further includes receiving a physical layer signal indicating that at least a subset of the final sub-portions is to be overwritten to a TDD state except for uplink transmission.

[0518] In some embodiments, the downlink portion is configured for downlink transmission without the possibility of dynamic override to a TDD state different from downlink transmission, wherein the uplink portion is configured for uplink transmission without the possibility of dynamic override to a TDD state different from uplink transmission.

[0519] In some embodiments, a user equipment device receives TDD configuration information from a first base station operating on a first frequency channel, the method further comprising: applying a time shift to a time slot of a current radio frame, wherein the time shift depends on an indicator of a TDD configuration used by a second base station, the second base station operating on a second frequency channel frequency adjacent to the first frequency channel, wherein after the time shift, the current semi-static TDD configuration of the radio frame complies with the TDD configuration of 3GPP LTE.

[0520] In some embodiments, the first length is specified based on a first number of complete time slots and a non-negative number x of symbols in a transition slot, wherein the second length is specified based on a second number of complete time slots and a non-negative number z of symbols in a transition slot, wherein a symbol of a transition slot that does not appear in either of the first x symbols of the transition slot or the last z symbols of the transition slot is a gap symbol.

[0521] In some embodiments, the first number, the number x, the second number, and the number z are configured to be consistent with the TDD configuration of 3GPP LTE.

[0522] In some embodiments, the middle portion includes a gap region, where the length of the gap region is received via higher layer signaling.

[0523] In some embodiments, the middle portion includes a gap region, wherein the length of the gap region is less than 0.0714 ms.

[0524] In some implementations, the frame length corresponds to one time slot.

[0525] In some embodiments, the frame length indicates a time value from the set given by {10ms, 5ms, 2ms, 1ms, 0.5ms, 0.25ms, 0.125ms}.

[0526] In some embodiments, the TDD configuration information is included in a physical layer signal.

[0527] In some implementations, multiple copies of the TDD configuration information are received to increase the probability of successfully decoding the TDD configuration information.

[0528] In some embodiments, the TDD configuration information includes a time at which the radio is to start TDD operation using a semi-static TDD configuration.

[0529] A set of embodiments may include a method for operating a user equipment device, the method comprising: receiving, by a radio component of the user equipment device, a TDD configuration index, wherein the TDD configuration index has a value selected from a predefined set of values, wherein the values ​​of the predefined set identify corresponding semi-static TDD configurations, wherein a first subset of the values ​​of the predefined set identify semi-static TDD configurations that are consistent with corresponding TDD configurations of 3GPP LTE until a time shift.

[0530] In some embodiments, the method further includes: when the value of the TDD configuration index is in the first subset, performing a TDD operation based on a semi-static TDD configuration corresponding to the value, wherein performing the TDD operation includes applying a time shift to a time slot of the current frame, wherein the amount of the time shift depends on the value.

[0531] In some embodiments, the predefined set includes values ​​of a second subset that is non-intersecting with the first subset, wherein for each value in the second subset, the corresponding semi-static TDD configuration includes: an initial part, which includes one or more consecutive time slots for downlink transmission; a terminal part, which includes one or more consecutive time slots for uplink transmission; and a middle part, which includes one or more consecutive time slots, and the TDD structure of the consecutive time slots will be dynamically determined by physical layer configuration information.

[0532] In some embodiments, the method further includes: in response to determining that the value of the TDD configuration index is in the second subset, performing TDD operations, including: receiving downlink data by the radio component from one or more symbols of the initial part; and transmitting uplink data by the radio component within one or more symbols of the termination part.

[0533] In some embodiments, the physical layer configuration information includes downlink control information.

[0534] In some embodiments, the physical layer configuration information includes a slot format indicator that appears in the group-common PDDCH.

[0535] In some embodiments, the physical layer configuration information includes downlink control information (DCI) and a slot format indicator (SFI).

[0536] In some embodiments, the predefined set includes a third subset, wherein for each value in the third subset, the corresponding semi-static TDD configuration includes only a single flexible time slot, whose TDD structure is dynamically determined by the physical layer configuration information.

[0537] In some embodiments, the predefined set includes a fourth subset, wherein for each value in the fourth subset, the corresponding semi-static TDD configuration includes, in chronological order: a first part, which includes one or more consecutive time slots, wherein the first part is allocated for downlink transmission without the possibility of dynamic overwrite to a TDD state other than downlink transmission; and a second part, which includes one or more consecutive time slots, wherein the second part is allocated for downlink transmission and has the possibility of dynamic overwrite to a TDD state other than downlink transmission.

[0538] In some embodiments, for each value in the fourth subset, the corresponding semi-static TDD configuration also includes, in chronological order: a third part, which includes one or more consecutive time slots, wherein the third part is allocated for uplink transmission and has the possibility of being dynamically overwritten to a TDD state other than uplink transmission, wherein the third part occurs in time after the second part; a fourth part, which includes one or more consecutive time slots, wherein the fourth part is allocated for uplink transmission and has no possibility of being dynamically overwritten to a TDD state other than uplink transmission.

[0539] In some embodiments, the semi-static TDD configurations corresponding to the predetermined set of values ​​are divided into groups corresponding to respective subcarrier spacings.

[0540] In some embodiments, the semi-static TDD configurations corresponding to the predetermined set of values ​​are divided into sets corresponding to different time periodicities.

[0541] A set of embodiments includes a method for operating a user equipment device, the method comprising: receiving, by a radio component of the user equipment device, physical layer configuration information from a first time slot of multiple time slots in a current frame, wherein the physical layer configuration information dynamically determines a TDD state of at least a portion of a designated time slot of the current frame, wherein the designated time slot is the first time slot in the current frame or a second time slot occurring after the first time slot.

[0542] In some embodiments, the method further includes performing downlink reception or uplink transmission in the portion of the indicated time slot based on the dynamically determined TDD state.

[0543] In some embodiments, the physical layer configuration information includes a slot format indicator, wherein the slot format indicator is included in a group common PDCCH of the first slot.

[0544] In some embodiments, the method further includes receiving, by the radio component, downlink control information that allocates time-frequency resources in at least a portion of the indicated time slot to a user equipment device, wherein the transmission direction indicated by the downlink control information is always consistent with the transmission direction indicated by the TDD state.

[0545] In some embodiments, the physical layer configuration information includes downlink control information (DCI).

[0546] In some embodiments, the DCI includes a parameter specifying a non-negative time slot distance between the first time slot and the indicated time slot.

[0547] In some embodiments, the parameter indicates that: the resource grant information is included in a first time slot; and the corresponding downlink data is included in the indicated time slot.

[0548] In some embodiments, the parameter indicates that: the downlink data is included in a first time slot; and the uplink acknowledgment of the downlink data is included in the indicated time slot.

[0549] In some embodiments, the parameter indicates that: the resource grant information is included in a first time slot; and the corresponding uplink data is included in the indicated time slot.

[0550] In some embodiments, the parameter indicates that: the uplink data is included in a first time slot; and the downlink acknowledgment of the uplink data is included in the indicated time slot.

[0551] In some implementations, the TDD state determined by the physical layer configuration information overwrites the TDD state determined by previously received semi-static configuration information.

[0552] In some embodiments, the indicated time slot or a portion thereof was previously configured by previously received semi-static configuration information to be flexible in its transmission direction.

[0553] In some embodiments, the TDD state is selected from a set of TDD states including uplink transmission and downlink transmission.

[0554] In some embodiments, the set of TDD states also includes: uplink center transmission; downlink center transmission; side link transmission; and reserved for future use.

[0555] A set of embodiments may include a method for operating a user equipment device, the method comprising: receiving, by a radio component of the user equipment device, dynamic physical layer configuration information, wherein the dynamic physical layer configuration information indicates a change in a transmission direction of a first resource within a given time slot of a current frame, wherein the first resource has been previously configured for transmission or reception of a periodic signal; and performing, by the radio component, reception or transmission of the periodic signal according to the changed transmission direction.

[0556] In some implementations, the periodic signal is a channel state information reference signal (CSI-RS), a sounding reference signal (SRS), or a CSI report.

[0557] In some implementations, the CSI-RS is a zero power CSI-RS (ZP CSI-RS) or a non-zero power CSI-RS (NZP CSI-RS).

[0558] In some embodiments, the dynamic physical layer configuration information is a slot format indicator included in a group common PDCCH for a given slot of a current frame or a previous slot.

[0559] In some embodiments, the dynamic physical layer configuration information is downlink control information (DCI).

[0560] A set of embodiments may include a method for operating a base station, the method comprising transmitting RRC signaling by a transmitter of the base station to a user equipment device, wherein the RRC signaling indicates a semi-static allocation of a first transmission direction corresponding to one or more time slots of a period, wherein the first transmission direction is either an uplink or a downlink; generating downlink control information indicating that time-frequency resources are allocated to one or more user equipment devices, wherein when the semi-static allocation continues, generating downlink control information so that whenever the time-frequency resources appear in one or more time slots, the transmission direction indicated by the downlink control information for the time-frequency resources is guaranteed to be consistent with the first transmission direction; and transmitting the downlink control information by the transmitter.

[0561] A set of embodiments may include a method for operating a user equipment device, the method comprising: receiving, by a radio component of the user equipment device, a slot format indicator (SFI) from a group common PDCCH, wherein the SFI has a value selected from a predefined set of values, wherein the values ​​of the predefined set identify corresponding TDD configurations, wherein a first subset of the values ​​of the predefined set corresponds to semi-static TDD configurations, and wherein a second subset of the values ​​of the predefined set corresponds to dynamic TDD configurations; in response to determining that the SFI is equal to a given value in the first subset, repeatedly performing TDD operations by the radio component according to the corresponding semi-static TDD configuration.

[0562] A set of embodiments may include a method for operating a user equipment device, the method comprising: according to a configured monitoring period, a radio component of the user equipment device periodically monitoring whether a time slot format indicator (SFI) is present; in response to detecting the presence of the SFI in the current period, the radio component performing TDD operation according to the dynamic allocation of one or more transmission directions indicated by the SFI for one or more time slots of the current period.

[0563] In some embodiments, the method may further include: in response to (a) failing to detect the SFI in the second period and (b) determining that downlink control information (DCI) for a given time slot has not been sent by the serving base station, the radio component performs transmission or reception in the given time slot based on the transmission direction indicated by the previously received SFI.

[0564] In some embodiments, the method may further include disabling transmission and reception by the radio component during the given time slot in response to (a) detecting the SFI in the second period and (b) determining that downlink control information (DCI) for the given time slot was not sent by the serving base station.

[0565] A group of embodiments includes a method for operating a base station, the method comprising: periodically transmitting a time slot format indicator by a radio component of the base station according to a transmission period, wherein each transmission of the time slot format indicator indicates that one or more transmission directions are dynamically allocated correspondingly to one or more time slots in a corresponding frame having a length equal to the transmission period; and for a current frame corresponding to a current transmission of the time slot format indicator, performing TDD operation on one or more time slots of the current frame by the radio component based on the dynamic allocation indicated by the current transmission of the time slot format indicator.

[0566] In some embodiments, the transmission period is selected from a group consisting of at least 1 ms, 5 ms, and 10 ms.

[0567] In some embodiments, the method further includes: for a next frame corresponding to a next transmission of the time slot format indicator, performing TDD operation on one or more time slots of the next frame based on the dynamic allocation indicated by the next transmission of the time slot format indicator, wherein the dynamic allocation indicated by the next transmission of the time slot format indicator is different from the dynamic allocation indicated by the current transmission of the time slot format indicator.

[0568] A group of embodiments includes a method for operating a user equipment device, the method comprising: receiving, by a radio component of the user equipment device, downlink control information that allocates a time-frequency resource set to the user equipment device and indicates a transmission direction of the time-frequency resource set, wherein the indicated transmission direction overwrites a flexible state indicated by a previously received time slot format indicator for the time-frequency resource set; and performing transmission or reception in the time-frequency resource set according to the indicated transmission direction by the radio component.

[0569] In some embodiments, the set of time-frequency resources is a PDSCH for a user equipment device, where the indicated transmission direction is downlink.

[0570] In some embodiments, the set of time-frequency resources is a PUSCH for a user equipment device, where the indicated transmission direction is uplink.

[0571] A group of embodiments include a method for operating a user equipment device, the method comprising: receiving, by a radio component of the user equipment device, a slot format indicator (SFI) from a first time slot of a current frame including one or more time slots, wherein the SFI indicates a dynamically allocated transmission direction of a first time-frequency resource that has been previously configured for transmitting or receiving a periodic signal; in response to determining that the indicated transmission direction is inconsistent with the transmission direction of the periodic signal, canceling the periodic signal at least for the current frame.

[0572] In some embodiments, the periodic signal is a channel state information reference signal (CSI-RS), wherein canceling the periodic signal includes not receiving the CSI-RS.

[0573] In some implementations, the CSI-RS is a zero power CSI-RS (ZP CSI-RS) or a non-zero power CSI-RS (NZP CSI-RS).

[0574] In some embodiments, the periodic signal is a sounding reference signal (SRS) or a CSI report, wherein the canceling of the periodic signal includes not transmitting the sounding reference signal or the CSI report.

[0575] A group of embodiments includes a method for operating a base station, the method comprising: transmitting a time slot format indicator by a transmitter of the base station in a current frame, wherein the time slot format indicator indicates a transmission direction of at least a portion of the indicated time slot of the current frame, wherein the indicated transmission direction is either downlink or uplink; generating downlink control information for allocating time-frequency resources to a user equipment device, wherein the downlink control information is generated so that whenever the time-frequency resources appear within the at least a portion of the indicated time slot, the transmission direction indicated by the downlink control information for the time-frequency resources is guaranteed to be consistent with the transmission direction indicated by the time slot format indicator; and transmitting the downlink control information by the transmitter to the user equipment device.

[0576] In some embodiments, the slot format indicator is included in the group-common PDCCH of the first slot of the current frame.

[0577] In some embodiments, the time slot format indicator also indicates a flexible state of another part of the current frame, wherein the other part does not intersect with the at least a part of the indicated time slot, and the method further includes: generating additional downlink control information, which allocates time-frequency resources within the other part of the current frame to a user equipment device or another user equipment device, wherein the downlink control information is generated so that the transmission direction indicated by the downlink control information for the other time-frequency resource is (a) either downlink or uplink, and (b) overwrites the flexible state of the other time-frequency resource; and transmitting the additional downlink control information.

[0578] In some embodiments, the method further includes transmitting another time slot format indicator in the next frame, wherein the other time slot format indicator indicates a flexible state of a portion of the next frame, and the method further includes: generating additional downlink control information, which allocates time-frequency resources in the next frame to a user equipment device or another user equipment device, wherein the additional downlink control information is generated so that the transmission direction indicated by the downlink control information for the time-frequency resources in the next frame is (a) either downlink or uplink, and (b) overwrites the flexible state of the time-frequency resources in the next frame; and transmitting the additional downlink control information.

[0579] A group of embodiments includes a method for operating a user equipment device, the method comprising: receiving, by a radio component of the user equipment device, RRC signaling, the RRC signaling indicating a semi-static allocation of a transmission direction for a given time slot in a cycle including one or more time slots; receiving, by the radio component, physical layer signaling, the physical layer signaling indicating a dynamic allocation of a transmission direction for at least a portion of a given time slot in a current frame conforming to the cycle, wherein the dynamically allocated transmission direction is inconsistent with the semi-statically allocated transmission direction; and performing transmission or reception, by the radio component, in the at least a portion of the given time slot according to the dynamically allocated transmission direction.

[0580] In some embodiments, the physical layer signaling includes a slot format indicator and / or downlink control information.

[0581] In some embodiments, the physical layer signaling includes downlink control information.

[0582] In some embodiments, whenever the physical layer signaling includes both a slot format indicator and downlink control information, the slot format indicator and the downlink control information coincide in the direction of transmission indicated for the at least a portion of a given slot.

[0583] One set of embodiments includes a base station comprising: an antenna; a radio component operably coupled to the antenna; and a processing element operably coupled to the radio component; wherein the antenna, the radio component and the processing element are configured to implement a method according to any of the preceding claims.

[0584] A set of embodiments comprises an apparatus comprising a processing element configured to implement a method according to any one of the preceding claims.

[0585] One set of embodiments comprises a computer program comprising instructions for performing any of the methods of any of the preceding claims.

[0586] One set of embodiments includes an apparatus comprising means for performing any of the method elements of any of the preceding claims.

[0587] One set of embodiments includes a method comprising any act or combination of acts as substantially described herein in the detailed description.

[0588] One set of embodiments includes a method as substantially described herein with reference to each or any combination of the figures included herein or with reference to each or any combination of the paragraphs in the detailed description.

[0589] One set of embodiments includes a wireless device configured to perform any action or combination of actions as substantially described herein in the detailed description.

[0590] One set of embodiments includes a wireless device comprising any component or combination of components as described herein in the detailed description included in a wireless device.

[0591] One set of embodiments includes a non-transitory computer-readable medium storing instructions that, when executed, cause performance of any action or combination of actions as substantially described herein in the detailed description.

[0592] One set of embodiments includes an integrated circuit configured to perform any action or combination of actions as substantially described herein in the detailed description.

[0593] The embodiments of the present disclosure may be implemented in any of a variety of forms. For example, some embodiments may be implemented as computer-implemented methods, computer-readable storage media, or computer systems. Other embodiments may be implemented using one or more custom-designed hardware devices such as ASICs. Other embodiments may be implemented using one or more programmable hardware elements such as FPGAs.

[0594] In some embodiments, a non-transitory computer-readable storage medium may be configured such that it stores program instructions and / or data, wherein if the program instructions are executed by a computer system, the computer system is caused to perform a method, such as any of the method embodiments described herein, or any combination of the method embodiments described herein, or any subset of any of the method embodiments described herein, or any combination of such subsets.

[0595] In some embodiments, a device (e.g., UE 106) may be configured to include a processor (or a group of processors) and a memory medium, wherein the memory medium stores program instructions, wherein the processor is configured to read and execute the program instructions from the memory medium, wherein the program instructions are executable to implement any of the various method embodiments described herein (or any combination of the method embodiments described herein, or any subset of any of the method embodiments described herein, or any combination of such subsets). The device may be implemented in any of a variety of forms.

[0596] Although the above embodiments have been described in considerable detail, numerous variations and modifications will become apparent to those skilled in the art once the above disclosure is fully appreciated. It is intended that the following claims be interpreted to encompass all such variations and modifications.

Claims

1. A method for wireless communication, comprising: At the User Equipment (UE): Receiving parameters defining a semi-static TDD configuration, wherein the parameters include: cycle; a first length specifying a duration of a downlink portion of the cycle, wherein the downlink portion occupies an initial position within the cycle, wherein the first length is specified based on a first number of complete time slots and a non-negative number x of symbols in time slots following the first number of complete time slots; and a second length specifying a duration of an uplink portion of the cycle, wherein the uplink portion occupies a terminal position within the cycle, wherein the second length is specified based on a second number of complete time slots and a non-negative number z of symbols in time slots preceding the second number of complete time slots; wherein symbols within the period that do not appear in the downlink portion or the uplink portion comprise a flexible portion, wherein symbols of the flexible portion comprise flexible symbols that can be used in either an uplink or a downlink direction; and Physical layer signaling is received, the physical layer signaling including downlink control information (DCI) dynamically indicating an uplink or downlink direction of at least one flexible symbol.

2. The method of claim 1, wherein the physical layer signaling further comprises a slot format indicator (SFI) and the SFI indicates cancellation of one or more periodic transmissions configured by RRC.

3. The method of claim 1, wherein the physical layer signaling further includes a slot format indicator (SFI) and the SFI is received on a group common control channel.

4. The method according to claim 1, The period is one of 10ms, 5ms, 2ms, 1ms, 0.5ms, 0.25ms or 0.125ms. The method of claim 1 , wherein the parameters defining a semi-static TDD configuration include a slot format indicator. The method of claim 1 , wherein the semi-static TDD configuration is received once per time slot.

7. The method according to claim 6, further comprising: A TDD operation is performed on the flexible part based on the DCI.

8. A method for wireless communication, comprising: At the User Equipment (UE): Receiving parameters defining a semi-static TDD configuration, the parameters comprising: cycle; a first length specifying a duration of a downlink portion of the cycle, wherein the downlink portion occupies an initial position within the cycle, wherein the first length is specified based on a first number of complete time slots and a non-negative number x of symbols in time slots following the first number of complete time slots; and a second length specifying a duration of an uplink portion of the cycle, wherein the uplink portion occupies a terminal position within the cycle, wherein the second length is specified based on a second number of complete time slots and a non-negative number z of symbols in time slots preceding the second number of complete time slots; wherein the symbols within the period that do not appear in the downlink portion or the uplink portion comprise a flexible portion, wherein the symbols of the flexible portion comprise flexible symbols that can be used in either the uplink or downlink direction; receiving downlink control information (DCI), the downlink control information including a schedule for one of an uplink data transmission or a downlink data transmission; and An uplink or downlink direction of the flexible symbol is determined based on the scheduling.

9. The method of claim 8, wherein the scheduling indicates a relative time for one of a physical downlink shared channel (PDSCH) transmission for downlink data or a physical uplink shared channel (PUSCH) transmission for uplink data.

10. The method according to claim 9, further comprising: The symbol is determined to be an uplink symbol based on the relative time to one of a physical downlink shared channel (PDSCH) transmission for downlink data or a physical uplink shared channel (PUSCH) transmission for uplink data.

11. The method according to claim 9, further comprising: determining a timing for sending an acknowledgement of the PDSCH based on the scheduling; as well as Based on the timing for sending the acknowledgment, it is determined that the symbol is an uplink symbol.

12. The method of claim 8, further comprising receiving a slot format indicator (SFI), wherein the SFI includes an indication of cancellation of one or more periodic transmissions configured by radio resource control.

13. The method of claim 8, further comprising receiving a slot format indicator (SFI), wherein the SFI is received on a group common control channel.

14. The method according to claim 8, wherein the period is 10ms, 5ms, 2ms, One of 1ms, 0.5ms, 0.25ms, or 0.125ms.

15. A method for wireless communication, comprising: At a base station (BS); Sending parameters defining a semi-static TDD configuration to a user equipment device (UE), the parameters comprising: cycle; a first length specifying a duration of a downlink portion of the cycle, wherein the downlink portion occupies an initial position within the cycle, wherein the first length is specified by a first number of complete time slots and a second number of symbols, wherein a time slot is a specified number of symbols in length; and a second length specifying a duration of an uplink portion of the cycle, wherein the uplink portion occupies a terminal position within the cycle, wherein the second length is specified by a third number of complete time slots and a fourth number of symbols; wherein the symbols within the period that do not appear in the downlink portion or the uplink portion comprise a flexible portion, wherein the symbols of the flexible portion comprise flexible symbols that can be used in either the uplink or downlink direction; sending downlink control information (DCI) to the UE, the downlink control information including a schedule for one of uplink data transmission or downlink data transmission; and Communicating with the UE in an uplink or downlink direction during the flexible symbols according to the schedule.

16. The method of claim 15, wherein the scheduling indicates a relative time for one of a physical downlink shared channel (PDSCH) transmission for downlink data or a physical uplink shared channel (PUSCH) transmission for uplink data.

17. The method according to claim 16, further comprising: The UE is communicated with in the uplink direction during a symbol based on the relative time for one of a physical downlink shared channel (PDSCH) transmission for downlink data or a physical uplink shared channel (PUSCH) transmission for uplink data.

18. The method according to claim 16, further comprising: determining a timing for receiving an acknowledgement for the PDSCH; as well as Communicating with the UE in the uplink direction during a symbol based on the timing for sending the acknowledgment.

19. The method of claim 15, further comprising sending a slot format indicator (SFI) to the UE, wherein the SFI includes an indication of cancellation of one or more periodic transmissions configured by radio resource control.

20. The method according to claim 15, wherein the period is 10ms, 5ms, 2ms, One of 1ms, 0.5ms, 0.25ms, or 0.125ms.

21. A non-transitory computer readable medium having program instructions stored thereon, wherein the program instructions, when executed by a processor, cause the processor to perform the method according to any one of claims 1 to 20.

22. A computer program product comprising program instructions which, when executed by a computer, cause the computer to perform the method according to any one of claims 1 to 20.

23. An apparatus for wireless communication, comprising a processor configured to cause a user equipment device (UE) to perform the method according to any one of claims 1 to 14.

24. The apparatus of claim 23, further comprising a radio operably coupled to the processor.

25. An apparatus for wireless communication, comprising a processor, the processor being configured to cause a base station to perform the method according to any one of claims 15 to 20.

26. The apparatus of claim 25, further comprising a radio operably coupled to the processor.

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