BR112017008297B1 - DYNAMIC UPLINK/DOWNLINK FRAME STRUCTURE FOR ENHANCED COMPONENT CARRIERS - Google Patents

Abstract

DYNAMIC UPLINK/DOWNLINK FRAME STRUCTURE FOR ENHANCED COMPONENT CARRIERS. Various aspects described in this document relate to communication using uplink and downlink dynamic transmission time slot (TTI) switching in a wireless network. A notification may be received from a network entity to switch a configurable TTI from downlink communications to uplink communications. The configurable TTI may be one of a plurality of TTIs in a frame structure that allows dynamic switching of configurable TTIs between downlink and uplink communications within a frame. Additionally, uplink communications may be transmitted to the network entity during the configurable TTI based, at least in part, on the notification.

Description

PRIORITY CLAIM

[0001] This Patent Application claims the priority of Provisional Application No. 62/068,277, entitled “BLIND UL/DL SYMBOL DETECTION IN DYNAMIC TDD SYSTEMS”, filed on October 24, 2014, of Provisional Application No. 62/074,469, entitled “DYNAMIC UPLINK/DOWNLINK FRAME STRUCTURE FOR ENHANCED COMPONENT CARRIERS”, filed on November 3, 2014 and U.S. Patent Application 14/862,997, entitled “DYNAMIC UPLINK/DOWNLINK FRAME STRUCTURE FOR ENHANCED COMPONENT CARRIERS” and filed on September 23, 2015, which are expressly incorporated into this document in its entirety by reference.

BACKGROUND

[0002] In this document, aspects, in general, related to communication systems and, more particularly, to frame structures used for communication between nodes in a wireless communication system are described.

[0003] Wireless communication systems are widely deployed to provide various telecommunications services, such as telephony, video, data, messaging and broadcasting. Typical wireless communication systems may employ multiple access technologies capable of supporting communication with multiple users by sharing available system resources (e.g., bandwidth, transmission power). Examples of such multiple access technologies include code division multiple access (CDMA) systems, time division multiple access (TDMA) systems, frequency division multiple access (FDMA) systems, orthogonal time division multiple access (FDMA) systems, frequency (OFDMA), single carrier frequency division multiple access systems (SC-FDMA) and synchronous time division code division multiple access systems (TD-SCDMA).

[0004] These multiple access technologies have been adopted in various communication standards to provide a common protocol that enables different wireless devices to communicate at a municipal, national, regional and even global level. An example of a telecommunications standard is Long Term Evolution (LTE). LTE is a set of enhancements to the Universal Mobile Telecommunications System (UMTS) mobile standard promulgated by the Third Generation Partnership Project (3GPP). It is designed to better support mobile broadband Internet access by improving spectral efficiency, reducing costs, improving services, making use of new spectrum, and better integrating with other open standards with the use of OFDMA downlink (DL), SC-FDMA uplink (UL), and multiple-input multiple-output (MIMO) antenna technology. However, as demand for mobile broadband access continues to increase, there is a need for additional improvements in LTE technology. Preferably, these enhancements should be applicable to other multiple access technologies and communication standards that employ those technologies.

[0005] For example, enhancements are proposed to further reduce latency in LTE networks. Since latency requirements are decreased, the underlying frame structures currently supported in LTE may not be able to effectively achieve the desired latency.

SUMMARY

[0006] Below, a summary of one or more aspects is presented in order to provide a basic understanding of such aspects. This summary is not an extensive overview of all aspects covered, and is not intended to identify key or critical elements of all aspects nor to delineate the scope of any or all aspects. The sole purpose is to present some concepts of one or more aspects in a simplified form as a preface to the more detailed description that is presented later.

[0007] According to an example, there is provided a method for communication that uses uplink and downlink dynamic transmission time interval (TTI) switching in a wireless network. The method includes receiving a notification from a network entity to switch a configurable TTI from downlink communications to uplink communications. The configurable TTI is one of a plurality of TTIs in a frame structure that allows dynamic switching of configurable TTIs between downlink and uplink communications within a frame. The method also includes transmitting uplink communications to the network entity during the configurable TTI based, at least in part, on the notification.

[0008] In other aspects, user equipment is provided for communication, which uses uplink and downlink TTI switching, in a wireless network. The user equipment includes a transceiver, at least one processor communicatively coupled to the transceiver via a bus for communicating signals on the wireless network, and a memory communicatively coupled to the at least one processor and/or the transceiver via the bus. The at least one processor and memory are operable to receive, via the transceiver, a notification from a network entity to switch a configurable TTI from downlink communications to uplink communications. The configurable TTI is one of a plurality of TTIs in a frame structure that allows dynamic switching of configurable TTIs between downlink and uplink communications within a frame. The at least one processor and memory are further operable to transmit, via the transceiver, uplink communications to the network entity during the configurable TTI based, at least in part, on nanonotification.

[0009] In another example, user equipment is provided for communication that uses uplink and downlink TTI switching in a wireless network. The user equipment includes a means for receiving a notification from a network entity to switch a configurable TTI from downlink communications to uplink communications. The configurable TTI is one of a plurality of TTIs in a frame structure that allows dynamic switching of configurable TTIs between downlink and uplink communications within a frame. The user equipment further comprises a means for transmitting uplink communications to the network entity during the configurable TTI based, at least in part, on nanonotification.

[0010] In other aspects, a computer-readable storage medium comprising computer-executable code for communication using uplink and downlink TTI switching in a wireless network is provided. The code includes code for receiving a notification from a network entity to switch a configurable TTI from downlink communications to uplink communications. The configurable TTI is one of a plurality of TTIs in a frame structure that allows dynamic switching of configurable TTIs between downlink and uplink communications within a frame. The code further includes code for transmitting uplink communications to the network entity during the configurable TTI based, at least in part, on notification.

[0011] To achieve the aforementioned and related purposes, the one or more aspects comprise resources fully described hereinafter and particularly pointed out in the claims. The following description and drawings in the annexes set forth in detail certain features of one or more aspects. These features are indicators, however, of only some of the various ways in which principles of various aspects may be employed, and this description is intended to include all such aspects and their equivalents.

BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 shows a block diagram that conceptually illustrates an example of a telecommunications system, in accordance with aspects described in this document.

[0013] Figure 2 is a diagram illustrating an example of an access network.

[0014] Figure 3 is a diagram illustrating an example of an evolved Node B and user equipment in an access network.

[0015] Figure 4 is a diagram illustrating an exemplary frame structure for dynamically switching configurable transmission time intervals (TTI) between downlink and uplink communications.

[0016] Figure 5 is a diagram illustrating an exemplary system for determining when configurable TTIs are switched between uplink and downlink communications, in accordance with aspects described in this document.

[0017] Figures 6 and 7 are flowcharts of exemplary methods for transmitting uplink communications based on switching detection of configurable TTIs from downlink to uplink communications.

[0018] Figure 8 is a flowchart of an exemplary method for determining whether a configurable TTI is configured for downlink or uplink communications.

[0019] Figure 9 is a flowchart of an exemplary method for indicating whether a configurable TTI is configured for downlink or uplink communications.

[0020] Figure 10 is a diagram illustrating an exemplary communication timeline that has TTIs configured for uplink and downlink communications in dynamic TDD frame structures.

[0021] Figure 11 is a diagram illustrating an exemplary downlink pilot continuous firing pattern for one or more reference signals, in accordance with aspects described in this document.

DETAILED DESCRIPTION

[0022] The detailed description presented below, in connection with the attached drawings, is intended to describe various configurations, and is not intended to represent the only configurations in which the concepts described in this document can be practiced. The detailed description includes specific details for the purpose of providing a thorough understanding of various concepts. However, it will be apparent to those skilled in the art that these concepts can be practiced without these specific details. In some cases, well-known structures and components are shown in block diagram form to avoid obscuring such concepts.

[0023] Various aspects of telecommunications systems will now be presented in reference to various apparatus and methods. These apparatus and methods will be described in the detailed description below and illustrated in the attached drawings by various blocks, modules, components, circuits, steps, processes, algorithms, etc. (collectively referred to as “elements”). These elements can be implemented using electronic hardware, computer software, or any combination thereof. Whether such elements are implemented as hardware or software depends on the particular application and design constraints imposed on the overall system.

[0024] By way of example, an element, or any portion of an element, or any combination of elements may be implemented with a “processing system” that includes one or more processors. Examples of processors include microprocessors, microcontrollers, digital signal processors (DSPs), field programmable gate arrays (FPGAs), programmable logic devices (PLDs), state machines, gated logic, discrete hardware circuits, and other suitable hardware configured to perform the various features described throughout this revelation. One or more processors in the processing system may execute software. Software shall be broadly interpreted to mean instructions, instruction sets, code, code segments, program code, programs, subprograms, software modules, applications, software applications, software packages, routines, subroutines, objects, executables , threads of execution, procedures, functions, etc., referred to either as software, firmware, middleware, microcode, hardware description language or otherwise.

[0025] Consequently, in one or more aspects, the described functions can be implemented in hardware, software, firmware or any combination thereof. If implemented in software, functions can be stored or encoded as one or more instructions or code in a computer-readable medium. Computer-readable media includes computer storage media. Storage media can be any available media that can be accessed by a computer. By way of example, and not limitation, such computer-readable media may comprise RAM, ROM, EEPROM, CD-ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other medium that can be used to carry or store the code of desired program in the form of instructions or data structures and that can be accessed by a computer. Magnetic disc and optical disc as used herein include compact disc (CD), laser disc, optical disc, digital versatile disc (DVD), and floppy disk, where magnetic discs generally reproduce data magnetically, while magnetic discs optical we reproduce data optically with lasers. Combinations of the above shall also be included in the scope of computer-readable media.

[0026] Various aspects related to communication in a wireless network are described in this document, according to a frame structure that allows dynamic switching between uplink (UL) and downlink (DL) communications. For example, the frame structure may include a plurality of transmission time slots (TTI) (e.g., time division duplexing (TDD) symbols), which may be configured or used for uplink and downlink communications. The frame structure may also include at least some TTIs that are dedicated downlink or uplink TTIs. For example, dedicated downlink and uplink TTIs can be provided to enable radio resource management (RRM) measurements, synchronization between communicating nodes, channel state information (CSI) feedback, random access channel communications (RACH) , scheduling requests (SR), etc. In the remaining configurable TTIs, one or more communication nodes may switch between uplink and downlink communications, and may notify other nodes of the switch. This allows the node to define the downlink/uplink configuration (e.g., of a given carrier) to facilitate improved communication throughput based on parameters of the one or more communicating nodes.

[0027] First, in reference to Figure 1, a diagram illustrates an example of a wireless communications system 100, in accordance with aspects described in this document. The wireless communications system 100 includes a plurality of access points (e.g., base stations, eNBs, or WLAN access points) 105, a plurality of user equipment (UEs) 115, and a core network 130. The access points 105 may include a programming component 302 configured to communicate resource grants (e.g., for data and/or control uplink communications) to the UEs 115 based on a frame structure, for example, but not limited to frame structure 400 (Figure 4), configured for lower latency communications . Similarly, one or more of the UEs 115 may include a communications component 361 configured to receive, decode, transmit, and operate using the frame structure (e.g., based on resource grants or other indicators received from an access point 105, as described in this document).

[0028] Some of the access points 105 may communicate with the UEs 115 under the control of a base station controller (not shown), which may be part of the core network 130 or certain access points 105 (e.g., base stations or eNBs ) in several examples. Access points 105 may communicate control information and/or user data with the main network 130 via alternate route links 132. In the examples, access points 105 may communicate, directly or indirectly, with each other via alternate route links 134, which They can be wired or wireless communication links. The wireless communications system 100 may support operation on multiple carriers (waveform signals of different frequencies). Multi-carrier transmitters can transmit modulated signals simultaneously on multiple carriers. For example, each communication link 125 may be a multicarrier signal modulated in accordance with the various radio technologies described above. Each modulated signal may be sent on a different carrier and may carry control information (e.g. reference signals, control channels, etc.), overload information, data, etc.

[0029] In this regard, a UE 115 can be configured to communicate with one or more access points 105 via multiple carriers using carrier aggregation (CA) (e.g., with an access point 105) and/or multiple connectivities (e.g. , with multiple access points 105). In both cases, the UE 115 may be configured with at least one primary cell (PCell) configured to support uplink and downlink communications between UE 115 and an access point 105. It should be understood that there may be a PCell for each communication link 125 between a UE 115 and a given access point 105. Additionally, each of the communication links 125 may have one or more secondary cells (SCell) that may support uplink and/or downlink communications as well. In some examples, PCell may be used to communicate at least one control channel, and SCell may be used to communicate one data channel. In one example, PCell and/or SCell may configure one or more enhanced component carriers (eCC) that provide lower latency communications (e.g., using frame structure 400 in Figure 4 or a similar frame structure with lower latency TTIs), as further described herein.

[0030] In some examples, at least a portion of the wireless communications system 100 may be configured to operate in multiple hierarchical layers in which one or more of the UEs 115 and one or more of the access points 105 may be configured to support transmissions in a hierarchical layer that has a reduced latency relative to another hierarchical layer. In some examples, a hybrid UE 115-a may communicate with access point 105-a in both a first hierarchical layer that supports first layer transmissions with a first subframe type and a second hierarchical layer that supports second layer transmissions with a second subframe type. For example, access point 105-a may transmit subframes of the second subframe type that are time division duplexed with subframes of the first subframe type.

[0031] In some examples, the hybrid UE 115-a may acknowledge the acknowledgment of a transmission by providing acknowledgment (ACK)/non-acknowledgment (NACK) for the transmission through, for example, a HARQ scheme. Hybrid UE acknowledgments 115-a for transmissions in the first hierarchical layer may be provided, in some examples, after a predefined number of subframes following the subframe in which the transmission was received. The hybrid UE 115-a, when operating in the second hierarchical layer, may, for example, recognize receipt in the same subframe as the subframe in which the transmission was received. The time required to transmit an ACK/NACK and receive a retransmission may be termed round trip time (RTT), and thus subframes of the second subframe type may have a second RTT that is shorter than an RTT for subframes of the first subframe type.

[0032] In other examples, a second-layer UE 115-b may communicate with the access point 105b only in the second hierarchical layer. Thus, the hybrid UE 115-a and the second-layer UE 115-b may belong to a second class of UEs 115 that can communicate in the second hierarchical layer, while the legacy UEs 115 may belong to a first class of UEs 115 that can communicate in the first hierarchical layer only. The access point 105-b and the UE 115-b may communicate in the second hierarchical layer via subframe transmissions of the second subframe type. The access point 105-b may exclusively transmit subframes of the second subframe type, or may transmit one or more subframes of the first subframe type in the first hierarchical layer that are time division multiplexed with subframes of the second subframe type. The second-layer UE 115-b, in the case where the access point 105-b transmits subframes of the first subframe type, may ignore such subframes of the first subframe type. Thus, the second-layer UE 115-b may recognize receiving transmissions in the same subframe as the subframe in which the transmissions are received. Thus, the second-layer UE 115-b can operate with reduced latency compared to UEs 115 that operate in the first hierarchical layer.

[0033] Access points 105 can communicate wirelessly with UEs 115 through one or more access point antennas. Each of the access point sites 105 may provide communications coverage for a respective coverage area 110. In some examples, the access points 105 may be referred to as a base transceiver station, a radio base station, a radio transceiver, a basic service set (BSS) ), an extended service set (ESS), a Node B, eNodeB, residential Node B, a Residential eNode, or some other suitable terminology. The coverage area 110 for a base station can be divided into sectors that constitute only a portion of the coverage area (not shown). The wireless communications system 100 may include access points 105 of different types (e.g., macro, micro, and/or peak base stations). Access points 105 may also utilize different radio technologies, such as WLAN and/or cellular radio access technologies (RAT). Access points 105 may be associated with the same or different access networks or operator facilities. The coverage areas of different access points 105, including the coverage areas of the same or different types of access points 105, which use the same or different radio technologies and/or which belong to the same or different access networks, may overlap.

[0034] In LTE/LTE-A network communication systems, the term evolved Node B (eNodeBouenNB) may be generally used to describe access points 105. The wireless communications system 100 may be an LTE/LTE-A network. Heterogeneous in which different types of access points provide coverage for various geographic regions. For example, each access point 105 may provide communications coverage for a macrocell, a picocell, a femtocell, and/or other cell types. Small cells, such as picocells, femtocells and/or other cell types, may include low-power nodes or LPNs. A macrocell generally covers a relatively large geographic area (e.g., several kilometers in radius) and may allow unrestricted access by UEs 115 with service subscriptions with the network provider. A small cell would generally cover a relatively smaller geographic area and may allow unrestricted access by UEs 115 with service subscriptions with the network provider, for example, and in addition to unrestricted access, it may also provide unrestricted access by UEs 115 that have an association with the small cell (e.g., UEs in a group of closed subscribers (CSG), UEs for home users, and the like). An eNB for a macrocell can be termed as a macro-eNB. An eNB for a small cell may be termed as a small cell eNB. An eNB may support one or multiple (e.g., two, three, four, and the like) cells.

[0035] The main network 130 may communicate with the NBs or other access points 105 via one or more alternative route links 132 (e.g., SI interface, etc.). Access points 105 may also communicate with each other, for example, directly or indirectly via alternate route links 134 (e.g., X2 interface, etc.) and/or via alternate route links 132 (e.g., via core network 130). The wireless communications system 100 may support synchronous or asynchronous operation. For synchronous operation, access points 105 may have similar frame timing, and transmissions from different access points 105 may be approximately time-aligned. For asynchronous operation, access points 105 may have different frame timing, and transmissions from different access points 105 may not be time-aligned. Furthermore, transmissions in the first hierarchical layer and the second hierarchical layer may or may not be synchronized between access points 105. The techniques described herein can be used for both synchronous and asynchronous operations.

[0036] The UEs 115 are dispersed throughout the wireless communications system 100, and each UE 115 may be stationary or mobile. A UE 115 may also be referred to by those skilled in the art as a mobile station, a subscriber station, a mobile unit, a subscriber unit, a wireless unit, a remote unit, a mobile device, a wireless device, a wireless communications device, a remote device, a mobile subscriber station, an access terminal, a mobile terminal, a wireless terminal, a remote terminal, a handset, a user agent, a mobile client, a client or some other suitable terminology. A UE 115 may be a cellular telephone, a personal digital assistant (PDA), a wireless modem, a wireless communication device, a handheld device, a tablet-type computer, a laptop-type computer, a cordless telephone, a wearable item, such as a watch or glasses, a wireless local circuit station (WLL) or the like. A UE 115 may have the ability to communicate with macro-eNodeBs, small cell eNodeBs, relays, and the like. A UE 115 may also have the ability to communicate over different access networks, such as cellular or other WWAN access networks or WLAN access networks.

[0037] Communication links 125 shown in wireless communications system 100 may include uplink (UL) transmissions from a UE 115 to an access point 105 and/or downlink (DL) transmissions from an access point 105 to a UE 115. Downlink transmissions may also be called forward link transmissions while uplink transmissions may also be called reverse link transmissions. Communication links 125 may carry transmissions from each hierarchical layer, which, in some examples, may be multiplexed into communication links 125. UEs 115 may be configured to communicate collaboratively with multiple access points 105 through, for example, Multiple Input and Multiple Output (MIMO), carrier aggregation (CA), Coordinated Multipoint (CoMP), multiple connectivities (e.g., CA with each of one or more access points 105) or other schemes. MIMO techniques use multiple antennas on access points 105 and/or multiple antennas on UEs 115 to transmit multiple data streams. Carrier aggregation may use two or more component carriers in the same or different server cell for data transmission. The CoMP may include techniques for coordinating transmission and reception by numerous access points 105 to improve overall transmission quality for UEs 115, as well as increasing network and spectrum utilization.

[0038] As mentioned, in some examples, access points 105 and UEs 115 may use carrier aggregation to transmit multiple carriers. In some examples, access points 105 and UEs 115 may simultaneously transmit in a first hierarchical layer, within a frame, one or more subframes, each of which has a first type of subframe that uses two or more separate carriers. Each carrier may have a bandwidth of, for example, 20 MHz, although other bandwidths may be used. The hybrid UE 115-a, and/or the second-layer UE 115-b may, in certain examples, receive and/or transmit one or more subframes in a second hierarchical layer that uses a single carrier that has a bandwidth greater than the bandwidth of one or more of the separate carriers. For example, if four separate 20 MHz carriers are used in a carrier aggregation scheme in the first hierarchical layer, a single 80 MHz carrier may be used in the second hierarchical layer. The 80 MHz carrier may occupy a portion of the radio frequency spectrum that overlaps, at least partially, the radio frequency spectrum used by one or more of the four 20 MHz carriers. In some examples, scalable bandwidth for the second hierarchical layer type may be a set of techniques combined to provide shorter RTTs, as described above, to provide additionally improved data rates.

[0039] Each of the different modes of operation that may be employed by the wireless communications system 100 may operate in accordance with frequency division duplexing (FDD) or time division duplexing (TDD). In some examples, different hierarchical layers may operate according to different TDD or FDD modes. For example, a first hierarchical layer may operate according to FDD, while a second hierarchical layer may operate according to TDD. In some examples, OFDMA communications signals may be used on communications links 125 for LTE downlink transmissions for each hierarchical layer, while single carrier frequency division multiple access (SC-FDMA) communications signals may be used on communications links 125 for uplink transmissions. ascending LTE in each hierarchical layer. Additional details related to the implementation of hierarchical layers in a system, such as wireless communications system 100, as well as other features and functions related to communications in such systems, are provided below in reference to the following figures.

[0040] Figure 2 is a diagram illustrating an example of an access network 200 in an LTE network architecture. In this example, the access network 200 is divided into numerous cellular regions (cells) 202. One or more lower power class eNBs 208 may have cellular regions 210 that overlap one or more cells 202. The lower power class eNB 208 may have a femtocell (e.g., residential eNB (HeNB)), picocell, microcell or remote radio head (RRH). The macro-eNBs 204 are each assigned to a respective cell 202 and are configured to provide an access point to the core network 130 for all UEs 206 in the cells 202. In one aspect, the eNBs 204 may include a programming component 302 configured to communicate grants resource for UEs 206 based on a frame structure, for example, but not limited to, frame structure 400 (Figure 4), configured for lower latency communications. Similarly, one or more of the UEs 206 may include a communications component 361 configured to receive, decode, transmit, and operate using the frame structure (e.g., based on resource grants or other indicators received from an access point 105, as described in this document). There is no centralized controller shown in this example of an access network 200, but a centralized controller can be used in alternative configurations. The SENBs 204 are responsible for all radio-related functions, which include radio carrier control, admission control, mobility control, scheduling, security, and connectivity to a serving communications port.

[0041] The modulation and multiple access scheme employed by access network 200 may vary depending on the particular telecommunications standard that is deployed. In LTE applications, OFDM can be used in DL and SC-FDMA can be used in UL to support both frequency division duplexing (FDD) and time division duplexing (TDD). As those skilled in the art will readily understand from the detailed description below, the various concepts presented in this document are well suited for LTE applications. However, these concepts can be readily extended to other communication standards that employ other modulation and multiple access techniques. By way of example, these concepts can be extended to Optimized Data Evolution (EV-DO) or Mobile Ultra Broadband (UMB). EV-DO and UMB are porar interface standards promulgated by the 3rd Generation Partnership Project 2 (3GPP2) as part of the CDMA2000 family of standards and employ CDMA to provide broadband Internet access to mobile stations. These concepts can also be extended to Universal Terrestrial Radio Access (UTRA) that employs wideband CDMA (W-CDMA) and other CDMA variants such as TD-SCDMA; Global System for Mobile Communications (GSM) that employs TDMA; and Evolved UTRA (E-UTRA), IEEE 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802.20, and OFDM Flash that employs OFDMA. UTRA, E-UTRA, UMTS, LTE and GSM are described in documents from the 3GPP organization. CDMA2000 and UMB are described in documents from the 3GPP2 organization. The actual wireless communication standard and multiple access technology employed will depend on the specific application and the overall design constraints imposed on the system.

[0042] The eNBs 204 may have multiple antennas that support MIMO technology. The use of MIMO technology enables eNBs 204 to explore the spatial domain to support spatial multiplexing, beamforming, and transmission diversity. Spatial multiplexing can be used to transmit different data streams simultaneously on the same frequency. Data streams can be transmitted to a single UE 206 to increase data rate or to multiple UEs 206 to increase overall system capacity. This is achieved by spatially pre-coding each data stream (i.e., applying a scale of one amplitude and one phase) and then transmitting each pre-coded spatial stream through multiple transmit antennas in the DL. The spatially pre-coded data streams arrive at the UE (or UEs) 206 with different spatial signatures, which enable each of the UEs 206 to retrieve the one or more data streams intended for that UE 206. In the UL, each UE 206 transmits a spatially pre-coded data stream. coded, which enables the eNB 204 to identify the source of each spatially pre-coded data stream.

[0043] Spatial multiplexing is generally used when channel conditions are good. When channel conditions are less favorable, beamforming can be used to focus transmission energy in one or more directions. This can be achieved by spatially pre-coding the data for transmission across multiple antennas. To achieve good coverage at the cell edges, single-flux beamforming transmission can be used in combination with transmission diversity.

[0044] In the following detailed description, various aspects of an access network will be described with reference to a MIMO system that supports OFDM in the DL. OFDM is a distributed spectrum technique that modulates data across numerous subcarriers within an OFDM symbol. The subcarriers are separated into precise frequencies. The spacing provides “orthogonality” that enables a receiver to recover data from the subcarriers. In the time domain, a protection interval (e.g., cyclic prefix) can be added to each OFDM symbol to combat interference between OFDM symbols. UL can use SC-FDMA in the form of a DFT distributed OFDM signal to compensate for high peak power to average power ratio (PAPR).

[0045] Figure 3 is a block diagram of an eNB 310 in communication with a UE 350 in an access network. In DL, upper layer packets from the core network are provided to a controller/processor 375. The controller/processor 375 implements the functionality of a layer 2 (L2) (e.g., a media access control (MAC) layer). In the DL, the controller/processor 375 provides header compression, encryption, packet segmentation and reordering, multiplexing between logical and transport channels, and radio resource allocations to the UE 350 based on various priority metrics. The controller/processor 375 is also responsible for HARQ operations, retransmission of lost packets, and signaling to the UE 350.

[0046] The transmission processor (TX) 316 implements various signal processing functions for the L1 layer (i.e., physical layer). Signal processing functions include coding and interleaving to facilitate forward error correction (FEC) in the UE 350 and mapping and mapping to signal constellations based on various modulation schemes (e.g., binary phase shift keying (BPSK), quadrature phase shift keying (QPSK), phase shift keying M (M-PSK), M quadrature amplitude modulation (M-QAM)). The coded and modulated symbols are then divided into parallel streams. Each stream is then mapped onto an OFDM subcarrier, multiplexed with a reference signal (e.g. pilot) in the time and/or frequency domain, and then combined together using an Inverse Fast Fourier Transform (IFFT) to produce a physical channel that carries a time domain OFD symbol stream. The OFDM stream is spatially pre-coded to produce multiple spatial streams. Channel estimates from a channel estimator 374 can be used to determine the coding and modulation scheme, as well as for spatial processing. The channel estimate may be derived from a reference signal and/or channel condition feedback transmitted by the UE 350. Each spatial stream is then provided to a different antenna 320 via a separate transmitter 318TX. Each 318TX transmitter modulates an RF carrier with a respective spatial flow for transmission. Additionally, the eNB 310 may include a programming component 302 configured to communicate resource grants to the UE 350 using a frame structure for lower latency communications through at least one CC, for example, but without limitation to frame structure 400 (Figure 4). .

[0047] In the UE 350, each receiver 354RX receives a signal through its respective antenna 352. Each receiver 354RX retrieves modulated information on an RF carrier and provides the information to the receive processor (RX) 356. The RX processor 356 implements various signal processing functions of the L1 layer. The RX processor 356 performs spatial processing on the information to retrieve any spatial streams destined for the UE 350. If multiple spatial streams are destined for the UE 350, they may be combined by the RX processor 356 into a single OFDM stream symbol. The RX processor 356 then converts the OFDM flow symbol from the time domain to the frequency domain using a Fast Fourier Transform (FFT). The frequency domain signal comprises a separate OFDM symbol stream for each subcarrier of the OFDM signal. The symbols on each subcarrier and the reference signal are recovered and demodulated by determining the signal constellation points most likely to be transmitted by the eNB 310. These soft decisions may be based on channel estimates computed by the channel estimator 358. The soft decisions are then decoded and deinterleaved to recover the data and control signals. which were originally transmitted by eNB 310 on the physical channel. Data and control signals are then provided to the controller/processor 359.

[0048] Controller/processor 359 implements the L2 layer. The controller/processor may be associated with a 360 memory that stores program codes and data. Memory 360 may be referred to as a computer-readable medium. In UL, the controller/processor 359 provides multiplexing between transport and logical channels, packet reassembly, decryption, header decompression, control signal processing to recover higher layer packets from the main network. The upper layer packets are then provided to a data collector 362, which represents all protocol layers above the L2 layer. Various control signals may also be provided to the data collector 362 for layer 3 (L3) processing (e.g., radio link control layer (RLC)). The controller/processor 359 is also responsible for error detection using an acknowledgment (ACK) and/or negative acknowledgment (NACK) protocol to support HARQ operations. Additionally, the UE 350 may include a communication component 361 configured to receive, decode, transmit, and operate using the frame structure for lower latency (e.g., based on resources granted in accordance with the frame structure by programming component 302 or other indicators received of eNB 310), as described in this document.

[0049] In UL, a data source 367 is used to provide higher layer packets to the controller/processor 359. The data source 367 represents all protocol layers above the L2 layer. Similar to the functionality described in connection with DL transmission by eNB 310, controller/processor 359 implements the L2 layer for the user plane and control plane providing header compression, encryption, packet segmentation and reordering, and multiplexing between logical and transport channels. based on radio resource allocations by the eNB 310. The controller/processor 359 is also responsible for HARQ operations, retransmission of lost packets, and signaling to the eNB 310.

[0050] Channel estimates derived by a channel estimator 358 from a reference or feedback signal transmitted by the eNB 310 can be used by the TX processor 368 to select appropriate coding and modulation schemes, and to facilitate spatial processing. The spatial streams generated by the TX processor 368 are provided to the different antenna 352 through separate transmitters 354TX. Each 354TX transmitter modulates an RF carrier with a respective spatial flow for transmission.

[0051] The UL transmission is processed in the eNB 310 in a manner similar to that described in connection with the receiver function in the UE 350. Each receiver 318RX receives a signal through its respective antenna 320. Each receiver 318RX recovers modulated information on an RF carrier and provides the information to a processor of RX 370. The RX 370 processor can deploy the L1 layer.

[0052] Controller/processor 375 implements the L2 layer. The controller/processor 375 may be associated with a memory 376 that stores program codes and data. Memory 376 may be referred to as a computer-readable medium. In UL, the controller/processor 375 provides multiplexing between transport and logical channels, packet reassembly, decryption, header decompression, control signal processing to recover higher layer packets from the UE 350. The controller/processor upper layer packets 375 can be provided to the main network. The controller/processor 375 is also responsible for error detection using an ACK and/or NACK protocol to support HARQ operations.

[0053] Figure 4 is a diagram illustrating a non-limiting example of a frame structure 400. Frame structure 400 depicts a TDD frame structure that has multiple time frames (Tm) equal to x milliseconds (ms), where x is a number positive integer. Each frame may include one or more TTIs configured to be a dedicated downlink TTI 402, a configurable downlink or uplink TTI 404, or a dedicated uplink TTI 406. In one example, a TTI may correspond to a TDD symbol (e.g., an OFDM symbol, a SC-FDM symbol, etc.). For example, the designation of dedicated downlink TTIs 402 and dedicated uplink TTIs 406 may enable radio resource management (RRM) measurements, synchronization between UEs and eNBs, channel state information (CSI) feedback transmissions, random access channel (RACH), SRs, etc. through dedicated TTIs. In one example, the dedicated downlink TTIs 402 and the dedicated uplink TTIs 406 may be radio resource control (RRC) configured between network nodes (e.g., between a UE and an eNB) or otherwise known to the network nodes. network.

[0054] Additionally, for example, the remaining TTIs 404, which are configurable for uplink and downlink communications, can be dynamically switched between uplink and downlink communications. These TTIs 404 are also referred to herein as “configurable TTIs”, and may include substantially any TTI that is not dedicated as a downlink or uplink TTI. A serving network node, such as an eNB, may determine one or more parameters related to the switching of the TTIs 404 between uplink and downlink communications (e.g., a period of time, such as a TTI, for which the switch is performed, a duration for the switching, etc.) and may indicate one or more parameters for other network nodes, such as a UE, to communicate with the serving network node, as further described herein. In this sense, a network node that has received a resource grant or other indicator of one or more parameters from the serving network node may determine whether a given TTI is configured to receive communications from the serving network node (downlink communications) or transmit communications to the serving network node. (uplink communications). In one example, the switching indication in this sense allows multiple contiguous (configurable) TTIs to be configured for the same type of communications (downlink or uplink) and can thus allow continuous firing communications.

[0055] Thus, in one example, TTIs 410, 412, 414 and 416 may be configured for downlink communications, and a switch may be indicated for uplink communications for TTIs 418 and 420, as described herein. Similarly, a switch may be indicated back for downlink communications to a configurable TTI after TTI 420. The use of configurable TTIs in this regard may allow dynamic determination of a split between uplink and downlink resources in a given frame, which may be based on communication-related parameters at the serving network node to enable more uplink or downlink capabilities to enhance uplink and downlink communications during the frame.

[0056] In a specific example, each TTI in frame structure 400 may be defined by an OFDM or SC-FDM symbol and may be of a shorter length than the LTE 1 millisecond subframe TTIs in order to provide lower latency communications. Thus, in an example, a frame may correspond to a subframe that includes a plurality of TTIs, a frame that includes a plurality of subframes that each includes a plurality of TTIs, etc. Dynamic switching between uplink and downlink TTIs can provide an adaptive framework for handling a desired distribution of uplink and downlink communications, which can allow certain uplink/downlink latencies to be achieved.

[0057] With reference to Figures 5 to 9, aspects are depicted with reference to one or more components and one or more methods that can perform the actions or functions described in this document. In one aspect, the term "component" as used herein may be one of the parts that constitute a system, may be hardware or software or some combination thereof, and may be divided into other components. Although the operations described below in Figures 6 through 9 are presented in a particular order and/or as being performed by an exemplary component, it should be understood that the ordering of the actions and the components performing the actions may be varied depending on the implementation. Furthermore, it should be understood that the following actions or functions may be performed by a specially programmed processor, a processor that executes specially programmed software or computer-readable media, or by any other combination of a hardware component and/or a software component capable of performing the described actions or functions.

[0058] Figure 5 illustrates an exemplary system 500 for communication between nodes in a wireless network based on a frame structure that facilitates dynamic switching of downlink/uplink TTIs. System 500 includes a UE 502 that communicates with an eNB 504 to access a wireless network, examples of which are described in Figures 1 to 3, above. In one aspect, the eNB 504 and the UE 502 may have established one or more downlink channels through which they communicate via downlink signals 509, which may be transmitted by NB 504 (e.g., via transceiver 556) and received by UE 502 (e.g., via transceiver 506) for communicating control and/or data messages (e.g., signaling) from the eNB 504 with the UE 502 via configured communication resources. Furthermore, for example, eNB 504 and UE 502 may have established one or more uplink channels through which they communicate via uplink signals 508, which may be transmitted by UE 502 (e.g., via transceiver 506) and received by NB 504 (e.g., via transceiver 556) for communicating control and/or data messages (e.g., signaling) from the UE 502 with the eNB 504 via configured communication resources. As further described herein, for example, the eNB 504 may communicate a resource grant or other indicator 580 that may indicate one or more parameters regarding switching communications from downlink to uplink (or vice versa) in a TTI.

[0059] In one aspect, the UE 502 may include one or more processors 503 and/or a memory 505 that may be communicatively coupled, for example, via one or more buses 507, and may operate in conjunction with or otherwise implement a communications component 361 to communicate with the eNB 504 so as to transmit uplink signals 508 thereto and/or receive downlink signals 509 therefrom in accordance with a frame structure that has configurable TTIs for uplink and downlink communications. For example, the various operations related to the communication component 361 may be implemented or otherwise performed by one or more processors 503 and, in one aspect, may be performed by a single processor, while in other aspects, different operations may be performed by a combination of two or more different processors. For example, in one aspect, the one or more processors 503 may include any processor or any combination of a modem processor, or a baseband processor, or a digital signal processor, or an application-specific integrated circuit (ASIC), or a transmission processor, receiver or a transceiver processor associated with transceiver 506. Additionally, for example, memory 505 may be a non-transitory computer-readable medium that includes, but is not limited to, random access memory (RAM), read-only memory (ROM), programmable ROM (PROM), erasable PROM (EPROM), electrically erasable PROM (EEPROM), a magnetic storage device (e.g., hard disk, floppy disk, magnetic tape), an optical disc (e.g., compact disc (CD), digital versatile disc (DVD)), a smart card, a flash memory device (e.g., card, stick, pen drive), a recorder, a removable disk, and any other suitable means for storing software and/or computer-readable code or instructions that can be accessed and read by a computer or one or more processors 503. Additionally, memory 505 or the computer-readable storage medium may be resident on the one or more processors 503, external to the one or more processors 503, distributed across multiple entities that include the one or more processors 503, etc.

[0060] In particular, the one or more processors 503 and/or memory 505 may perform actions or operations defined by communication component 361 or its subcomponents. For example, the one or more processors 503 and/or the memory 505 may execute actions or operations defined by a resource grant receiving component 510 to obtain resource grants from the eNB 504, which may include or otherwise implicitly indicate one or more TTIs configured for network communications. uplink and downlink communications. In one aspect, for example, the resource grant receiving component 510 may include hardware (e.g., one or more processor modules of the one or more processors 503) and/or computer-readable code or instructions stored in memory 505 and executable by at least one of the one or more processors 503 to perform the operations of receipt and/or processing of specially configured resource grants described in this document. Additionally, for example, the one or more processors 503 and/or memory 505 may perform defined operations or operations by a downlink/uplink switching detection component 512 to determine one or more configurable TTIs in which communications with eNB 504 switch from downlink to uplink and /or vice versa. In one aspect, for example, the downlink/uplink switching detection component 512 may include hardware (e.g., one or more processor modules of the one or more processors 503) and/or computer-readable code or instructions stored in memory 505 and executable by at least one of the one or more processors 503 to perform the specially configured downlink/uplink switching detection operations described in this document. Additionally, for example, the one or more processors 503 and/or memory 505 may optionally perform operations or operations defined by a reference signal monitoring component 514 to monitor communication resources for one or more reference signals, which may be used to determine the possibility of communications in a configurable TTI have been switched to downlink communications from uplink communications in a previous TTI and/or vice versa. In one aspect, for example, the reference signal monitoring component 514 may include hardware (e.g., one or more processor modules of the one or more processors 503) and/or computer-readable code or instructions stored in memory 505 and executable by at least one of the one or more processors 503 to perform the operations of specially configured reference signal monitoring described in this document.

[0061] Similarly, in one aspect, the eNB 504 may include one or more processors 553 and/or memory 555 that may be communicatively coupled, for example, via one or more buses 557, and may operate in conjunction with or otherwise deploying one or more programming components 302 for communicating one or more resource grants or other indicators 580 to a UE 502, which may indicate one or more parameters regarding switching from downlink to uplink communications, and/or vice versa, in one or more TTIs. For example, the various functions related to programming component 302 may be implemented or otherwise executed by one or more processors 553 and, in one aspect, may be performed by a single processor, while in other aspects, different functions among the functions may be executed by a combination of two or more different processors, as described above. . It should be understood that, in an example, the one or more processors 553 and/or memory 555 may be configured as described in the examples above in relation to the one or more processors 503 and/or memory 505 of the UE 502.

[0062] In one example, the one or more processors 553 and/or memory 555 may perform actions or operations defined by programming component 302 or its subcomponents. For example, the one or more processors 553 and/or the memory 555 may perform actions or operations defined by a resource grant generating component 520 to generate one or more resource grants and/or other indicators 580 for the UE 502, wherein the resource grant and/or or other indicator 580 may indicate one or more parameters in relation to a TTI during which communications are switched from downlink to uplink, and/or vice versa. In one aspect, for example, the resource grant generating component 520 may include hardware (e.g., one or more processor modules of the one or more processors 553) and/or computer-readable code or instructions stored in memory 555 and executable by at least one of the one or more processors 553 to perform the operations of generation of specially configured resource grants described in this document. Additionally, for example, the one or more processors 553 and/or memory 555 may perform actions or operations defined by an optional downlink/uplink switching indication component 522 to indicate, via resource grant or other indicators 580, one or more parameters with respect to a TTI during the which communications are switched from downlink to uplink, and/or vice versa. In one aspect, for example, the downlink/uplink switching indication component 522 may include hardware (e.g., one or more processor modules of the one or more processors 553) and/or computer-readable code or instructions stored in memory 555 and executable by at least one of the one or more processors 553 to perform the specially configured downlink/uplink switching indication operations described in this document.

[0063] It should be understood that transceivers 506, 556 can be configured to transmit and receive wireless signals through one or more antennas, an RF front-end, one or more transmitters, and one or more receivers. In one aspect, the transceivers 506, 556 can be tuned to operate at specified frequencies so that the UE 502 and/or the eNB 504 can communicate at a certain frequency. In one aspect, the one or more processors 503 may configure the transceiver 506 and/or one or more processors 553 may configure the transceiver 556 to operate at a specified frequency and power level based on a configuration, a communication protocol, etc. to communicate uplink signals 508 and/or downlink signals 509, respectively, via related uplink or downlink communication channels.

[0064] In one aspect, transceivers 506, 556 may operate multiple bands (e.g., with the use of a multi-band, multi-mode modem, not shown) in order to process digital data sent and received using transceivers 506, 556. In In one aspect, transceivers 506, 556 may be multiband and configured to support multiple frequency bands for a specific communications protocol. In one aspect, transceivers 506, 556 can be configured to support multiple operational networks and communications protocols. Thus, for example, transceivers 506, 556 may enable the transmission and/or reception of signals based on a specific modem configuration.

[0065] Figure 6 illustrates an exemplary method 600 for communicating with a network entity (e.g., through a UE) based on a frame structure that facilitates dynamic switching between TTIs configured for downlink and uplink communications. In Block 602, a UE may optionally communicate with a network entity using a frame structure that allows dynamic switching of configurable TTIs between downlink and uplink communications within the frame. The communication component 361 of UE 502 (Figure 5) may communicate with the network entity (e.g., the eNB 504) using a frame structure that allows dynamic switching of configurable TTIs between downlink and uplink communications within the frame. In one example, the resource grant generating component 520 may configure the UE 502 with designated resources based on the frame structure, and the resource grant receiving component 510 may receive the resources for communicating with the eNB 504 through the communication component 361. In As an example, the frame structure may be similar to frame structure 400 (Figure 4), which includes dedicated downlink TTIs, configurable TTIs for both uplink and downlink communications, and/or dedicated uplink TTIs. Thus, for example, the resource grant generating component 520 may generate, and the resource grant receiving component 510 may receive, a downlink resource grant that indicates downlink resources in corresponding TTIs that are configurable as downlink or uplink resources or in TTIs that are dedicated downlink TTIs, an uplink resource grant that indicates uplink resources in corresponding TTIs that are configurable as downlink or uplink resources, or in TTIs that are dedicated uplink TTIs, etc.

[0066] For example, the UE 502 and the eNB 504 may communicate downlink or uplink continuous triggers such that the TTIs configurable for downlink or uplink communications are configured for downlink communications for one or more TTIs and then for downlink communications. uplink to one or more TTIs and then back to downlink, and so on. As described, in one example, the eNB 504 may define switching between downlink and uplink communications on these TTIs in order to achieve a desired uplink or downlink latency, which may include defining the switching based, at least in part, on a load on the eNB 504, a situation of temporary storage, quality of service, subscription level, etc. of UE 502, and/or similar parameters that may indicate a demand for communication resources. In this sense, as further described in this document, the eNB 504 may indicate one or more parameters in relation to a switch in the configurable TTIs from downlink to uplink and/or vice versa for the UE 502 and/or one or more other UEs. However, in an example, it should be understood that the UE 502 and/or one or more other UEs do not need to communicate with the network entity through resources granted to receive information regarding the switching of configurable TTIs from downlink to uplink communications, and /or vice versa, as described in this document.

[0067] Accordingly, in Block 604, a UE may receive a notification from the network entity to switch a configurable TTI from downlink to uplink communications. The downlink/uplink switching detection component 512 may receive notification from the network entity to switch a configurable TTI from downlink to uplink communications. It should be understood that various notifications for switching a configurable TTI from downlink to uplink communications may be employed in this regard. In an example, upon receiving the notification in Block 604, in Block 606, the UE may optionally receive the notification in an uplink resource grant that indicates the configurable TTI. Thus, for example, when the UE 502 is programmed resources by eNB 504, the resource grant generation component 520 may generate an uplink resource grant 580 for the UE 502 related to a given TTI, and the scheduling component 302 may transmit the uplink resource grant uplink 580 (e.g., via transceiver 556) to the UE 502. In this example, the resource grant receiving component 510 may receive notification on an uplink resource grant 580 received from the eNB 504 (e.g., via transceiver 506) which indicates the configurable TTI. For example, the downlink/uplink switching detection component 512 may determine downlink switching to uplink switching at a given TTI based, at least in part, on a TTI or similar timing information indicated in the uplink resource grant. In one example, the downlink/uplink switch detection component 512 may determine that the downlink to uplink switch occurs at the TTI that corresponds to the granted uplink resources, numerous TTIs before the granted uplink resources, numerous TTIs after the TTI in the which uplink resource grant is received, a TTI indicated as the switching TTI in the resource grant, etc.

[0068] In another example (e.g., when the UE 502 is not programmed by the NB 504 or in any case), the downlink/uplink switching indication component 522 may indicate a switch from downlink to uplink communications at a configurable TTI using a indicator. Thus, for example, upon receiving the notification in Block 604, in Block 608, the UE may optionally receive the notification as an indicator in a previous TTI configured for downlink communications. For example, the downlink/uplink switching detection component 512 may receive the notification as an indicator 580 in the previous TTI configured for downlink communications (e.g., a warning bit that may be transmitted in a downlink signal 509, with the use of a downlink channel, etc.), in which case the downlink/uplink switching detection component 512 may receive the bit or other indicator 580 (e.g., via transceiver 506), and may determine the configurable TTI as a nearby TTI where communications are switched to uplink communications. The indicator may indicate at least one of the switching that occurs at the next TTI, any number of anticipated TTIs at which switching will occur (for example, a known or configured number of TTIs after a warning bit is received or an explicit amount of TTIs specified in the indicator), an explicit TTI at which switching will occur at which the TTIs can be identified (e.g., by frame quantity, subframe quantity, etc.), and/or the like. For example, the downlink/uplink switching detection component 512 may monitor eNB 504 communications to detect the indicator.

[0069] For example, when the UE 502 is programmed by eNB 504, the downlink/uplink switching detection component 512 may monitor communications from eNB 504 upon receipt of a downlink grant or other indication of a downlink grant duration. Otherwise, the UE 502 may monitor eNB 504 communications on substantially any configurable TTI (and/or a dedicated downlink TTI) until the switching indication (e.g., an uplink resource grant or other indicator 580) is received from the eNB 504.

[0070] Additionally, for example, the resource grant or other indicator 580 may include one or more parameters that indicate a duration of the uplink TTIs until the configurable TTIs are again switched to downlink communications. For example, the one or more parameters may correspond to a number of TTIs indicated in the resource grant or other indicator 580 that refer to a continuous shot length of the uplink continuous shot. In an example, a non-zero value for the number of TTIs may also be the parameter that indicates switching to uplink communications at a next TTI. In any case, the downlink/uplink switching detection component 512 may detect the switch to uplink communications for the duration, and at the end of the duration, may determine a switch back to downlink communications, as further described herein.

[0071] In additional examples, the eNB 504 may not communicate an explicit notification to switch the TTIs between downlink and uplink communications, and/or vice versa, but instead, the eNB 504 communications may implicitly notify the switch. Consequently, the downlink/uplink switching detection component 512 may attempt to blindly detect the possibility that a given TTI is configured for downlink or uplink communications. For example, upon receiving the notification in Block 604, in Block 610, the UE may optionally detect one or more reference signals in previous configurable TTIs, and determine that the configurable TTI is configured for uplink communications based, at least in part, on the detection that The configurable TTI does not include one or more reference signals. For example, the reference signal monitoring component 514 may detect the one or more reference signals in the preceding configurable TTIs, and the downlink/uplink switching detection component 512 may determine that the configurable TTI is configured for uplink communications with based, at least in part, on detecting that the configurable TTI does not include one or more reference signals.

[0072] In an example, upon detecting that the configurable TTI does not include the one or more reference signals in Block 610, in Block 612, the UE may optionally detect that the configurable TTI does not include the one or more reference signals by detecting a sequence- pilot that corresponds to one or more reference signals in the previous configurable TTIs and determining that the pilot sequence is not present in the configurable TTI. The reference signal monitoring component 514 may detect the pilot sequence that corresponds to one or more reference signals in the previous configurable TTIs, and may determine whether the pilot sequence is present in the configurable TTI.

[0073] In one example, the eNB 504 may transmit reference signals, such as a cell specific reference signal (CRS), according to the pilot sequence. The eNB 504 may transmit reference signals using a dense pilot signal, which may include transmitting a reference signal with a dense pilot configuration (e.g., using substantially all of the available bandwidth, or at least more than one subcarrier frequency, to transmit the reference signal in a TTI). This may facilitate improved reception and detection of the pilot signal by the UE 502. In another example, the eNB 504 may transmit the reference signal using a relatively sparse pilot configuration (e.g., a pilot configuration typically defined for a RAT, such as LTE, which may use less bandwidth than a dense pilot configuration). In either case, reference signals transmitted as a pilot signal in that direction may be used to perform channel estimation to coherently detect subsequent transmissions of the reference signal or related pilot sequences. In this example, the reference signal monitoring component 514 may monitor signals in the previous configurable TTIs, and may observe the transmitted reference signal as a pilot signal. The reference signal monitoring component 514 may therefore use the reference signal to perform channel estimation, and the channel estimates obtained from the previous configurable TTIs may be used to assist in detecting reference signals in subsequent TTIs to determine which a subsequent TTI is a downlink TTI based on the detection of a related (e.g., similar) pilot sequence in the subsequent TTI.

[0074] In this example, the reference signal monitoring component 514 may monitor the channel for reference signals in the previous configurable TTIs configured for downlink communications (or in dedicated downlink TTIs), and may observe or otherwise determine the pilot sequence of reference signals (e.g., CRS) transmitted by NB 504. The reference signal monitoring component 514 may therefore attempt to coherently detect the reference signal (e.g., CRS) in subsequent downlink TTIs, such as the configurable TTI, with based on the detected pilot sequence. When the reference signal monitoring component 514 does not find reference signals that have the pilot sequence determined in the configurable TTI, this may be a notification that the configurable TTIs have switched from downlink to uplink communications, and the signal switching detection component 514 downlink/uplink 512 may determine that communications have been switched from downlink to uplink communications at the configurable TTI (or before).

[0075] It should be understood that, in another example, the reference signal monitoring component 514 may not rely on the channel estimates of the previous configurable TTIs, but instead rely on the current TTI to determine the pilot sequence, thus detecting, of non-coherent mode, reference signals received in downlink signals 509 from the eNB 504. For example, the reference signal monitoring component 514 may non-coherently detect reference signals where the previous configurable TTIs were not downlink TTIs or otherwise , in which coherent detection is not used or supported (for example, which may conserve memory that could otherwise be used to store information about previously detected reference signals). In either case, as described, the downlink/uplink switching detection component 512 may detect that a TTI is configured for downlink communications based, at least in part, on detection of the reference signals in the TTI. Similarly, in one example, the downlink/uplink switching detection component 512 may detect that a TTI is not configured for downlink communications (e.g., is configured for uplink communications) based, at least in part, on detection of reference signals or related pilot sequences in the TTI. Thus, the downlink/uplink switching detection component 512 may receive notification to switch the configurable TTI based on determining (non-coherently) whether the TTI includes one or more reference signals associated with downlink communications.

[0076] Furthermore, in one example, upon receiving the notification in Block 604, in Block 614, the UE may optionally determine that the previous configurable TTIs are configured for downlink communications, further based, at least in part, on the decoding of a physical layer channel of one or more signals received in the previous configurable TTI. The downlink/uplink switching detection component 512 may determine that the previous configurable TTIs are configured for downlink communications, further based, at least in part, on the decoding of a physical layer channel of one or more signals received in the previous configurable TTI. This may have occurred before detecting that the configurable TTI does not include the one or more reference signals in Block 610, so as to implicitly receive notification that the configurable TTIs are switched from downlink to uplink communications. In another example, the downlink/uplink switching detection component 512 may additionally or alternatively attempt to decode a known physical layer channel in signals received from the eNB 504 to confirm that the previous configurable TTIs have been configured for downlink communications as further described herein. In one example, the downlink/uplink switching detection component 512 may attempt to decode the physical layer channel, such as the physical control format indicator channel (PCFICH), based on the received CRS to confirm that the previous configurable TTIs corresponded to the forward link communications. downlink.

[0077] In either case, based on receipt of explicit or implicit notification to switch the configurable TTIs from downlink to uplink communications, the communications component 361 may switch the transceiver 506 or related resources (e.g., an antenna, one or more processors 503 that can operate the antenna, such as a modem processor, etc.) from a receive mode to a transmit mode. In another example, the communications component 361 may enter sleep mode as described herein, which may include disabling one or more components of the transceiver 506, a related processor (e.g., a modem processor), an antenna, etc. over a period of time based on detection of the configurable TTI being configured for uplink communications. When the UE 502 is not programmed to communicate with the eNB 504, for example, this may conserve resources and decrease the power consumption of the UE 502.

[0078] In Block 616, the UE may transmit uplink communications to the network entity during the configurable TTI based, at least in part, on notification. For example, with the transceiver 506 in transmit mode as described, the communication component 361 can transmit uplink communications to the network entity (e.g., eNB 504) during the configurable TTI based, at least in part, on notification. For example, a first TTI in an uplink data stream (e.g., and/or dedicated uplink TTIs) may be used by scheduled and/or unscheduled UEs 502 to transmit uplink control information to the eNB 504, such as data reports. CSI, ACK/NACK feedback, SRs, etc. Consequently, in this example, programming to transmit at least part of the uplink control information may not be required of the eNB 504, as the UE 502 may detect the switching of the configurable TTI for uplink communications (e.g., based on a resource grant or other indicator 580, as described above ) and can consequently transmit control data in the configurable TTI. This can additionally conserve resources and reduce latency, as explicit resource granting for control data communications may not be necessary. In this example, however, it should be understood that control channel resources may be semi-statically allocated in the UE 502 to communicate control data in the first uplink TTIs (e.g., in an initial resource grant of the eNB 504, etc.), but may not be necessary for each transmission of data from control on a first uplink TTI of an uplink continuous shot.

[0079] Furthermore, when switching to uplink communications is part of a resource grant received by the UE 502, the communication component 361 may transmit additional uplink communications to the UE 502 in the continuous firing of uplink data. For example, the communications component 361 may continue transmission to the eNB 504 until the continuous firing of uplink data has terminated (e.g., until the eNB 504 indicates the switching of configurable TTIs from uplink to downlink communications by an explicit indication eNB 504, an indication of numerous TTIs related to continuously firing uplink data until switching to downlink communications, detecting a switch based on receipt of one or more downlink signals from the eNB 504, etc., as further described herein).

[0080] Figure 7 also illustrates an exemplary method 700 for communicating with a network entity (e.g., through a UE) based on a frame structure that facilitates dynamic switching between TTIs configured for downlink and uplink communications. In Block 602, the UE may optionally communicate with a network entity using a frame structure that allows dynamic switching of configurable TTIs between downlink and uplink communications within the frame, as described in relation to Figure 6 above. In Block 604, the UE may receive a notification from the network entity to switch a configurable TTI from downlink communications to uplink communications, as described in relation to Figure 6 above. In Block 616, the UE may transmit uplink communications to the network entity during the configurable TTI based, at least in part, on notification, as described in relation to Figure 6 above.

[0081] In Block 702, the UE may optionally determine a first configurable TTI to be switched for downlink communications based, at least in part, on nanonotification. For example, the downlink/uplink switching detection component 512 may determine the first configurable TTI to be switched for downlink communications based, at least in part, on nanonotification. As described, the downlink/uplink switch indication component 522 may indicate a switch in the configurable TTIs from uplink to downlink with the use of one or more indicators, which may be the same indicator used to provide the notification to switch from downlink to uplink communications. ascending, as received by communication component 361 (e.g., in Block 604). For example, the resource grant generation component 520 may specify a continuous firing length of the uplink resource grant provided to the UE 502 (e.g., where the continuous firing length may correspond to numerous TTIs), an index of the TTI during which communications will be switched back to downlink, etc. In another example, the downlink/uplink switching indication component 522 may generate the other downlink to uplink switching indicator (e.g., the TTI carrying the warning bit) to also include one or more parameters (e.g., signal signaling). L1) which indicates when a switch back to downlink communications will occur (e.g., an uplink continuous trigger length, an index of the TTI during which communications will switch back to downlink, etc.). Accordingly, in either case, the downlink/uplink switch detection component 512 may detect the switch in the configurable TTIs from uplink to downlink communications (e.g., for a downlink continuous trigger) based on one or more parameters. received in uplink resource grantor other indicator 580.

[0082] In another example, the programming component 302 may begin transmitting downlink signals 509 without necessarily indicating switching to downlink to the UE 502 or one or more other UEs. Thus, for example, the downlink/uplink switching detection component 512 may detect switching based on receipt of one or more downlink signals, as further described herein. Accordingly, in one example, by determining the first configurable TTI to be switched for downlink communications in Block 702, in Block 704, the UE may monitor network entity signals in one or more configurable TTIs after at least one TTI through which uplink communications are switched. transmitted, and determine switching to the one or more configurable TTIs back for downlink communications based on detection of a reference signal or decoding of a downlink control channel. For example, the reference signal monitoring component 514 may monitor network entity signals (e.g., reference signals from the eNB 504) at one or more configurable TTIs after the at least one TTI through which uplink communications are transmitted (e.g., by UE 502 ), and may determine the switching of one or more configurable TTIs back to downlink communications based on detection of a reference signal or decoding of a downlink control channel.

[0083] For example, when downlink reference signals are detected from the eNB 504 following a determined switch from downlink to uplink communications, this may indicate a switch back from uplink to downlink communications in the configurable TTIs (e.g., where the signal downlink reference number is received on a configurable TTI and/or is not received on a dedicated downlink TTI). For example, when the UE 502 is programmed by the NB 504, but has not received an indication of when the switch to downlink communications occurs, the communication component 361 may transmit its uplink data information through one or more uplink TTIs in accordance with its uplink resource grant. uplink received from the eNB 504, and then the reference signal monitoring component 514 may begin monitoring downlink reference signals from the eNB 504 to determine when the configurable TTIs are switched from uplink communications back to downlink communications. This may include communication component 361 that switches transceiver 506 to a receive mode to monitor reference signals after transmission of uplink data information. In another example, when the UE 502 is not programmed by the NB 504 in any way, the communication component 361 may possibly transmit uplink control information through the first uplink TTI in the indicated uplink data burst and then the reference signal monitoring component 514 may begin monitoring downlink reference signals from the eNB 504 to determine when the configurable TTIs are switched from uplink communications back to downlink communications. Again, this may include communications component 361 that switches transceiver 506 to a receive mode to monitor reference signals after transmitting uplink or otherwise control information.

[0084] In one example, monitoring signals from the eNB 504 in this sense can facilitate blind detection of the possibility of a given TTI being downlink or uplink. As described above, the eNB 504 may transmit reference signals, such as CRS, in accordance with a pilot sequence. In this example, signal monitoring in Block 704 may include monitoring signals that have a known or learned pilot sequence. In one example, the reference signal monitoring component 514 may observe reference signals received from the eNB 504 in previous downlink TTIs, and may detect the pilot sequence used (e.g., based on a channel estimate of the reference signals received from of eNB 504). The reference signal monitoring component 514 may therefore attempt to detect reference signals in subsequent downlink TTIs based on the detected pilot sequence. Furthermore, in one example, the reference signal monitoring component 514 may attempt to decode a known physical layer channel into subsequent received signals based on the received reference signals (e.g., CRS), such as a downlink control channel (e.g., control channel). physical downlink channel (PDCCH), physical control format indicator channel (PCFICH), or a similar channel) to confirm that the configurable TTI is switched to downlink communications.

[0085] In either case, when the first configurable TTI to be switched is determined in Block 702, the communication component 361 may switch the transceiver 506, as described, to a receive mode for receiving downlink signals 509 from the eNB 504 Thus, in Block 706, the UE may optionally receive control data from the network entity in the first configurable TTI. The communication component 361 may receive control data from the network entity (e.g., eNB 504) in the first configurable TTI. As described, this may include receiving downlink signals 509 from the eNB 504, which may include control data from the eNB 504. In one example, the control data may indicate a resource grant to the UE 502 and/or an indication of when the TTIs will be switched back to uplink communications. In either case, for example, the communications component 361 may continue to receive downlink signals 509 on one or more TTIs, and the method 700 may accordingly continue to 604 to receive another notification to switch a configurable TTI from downlink communications to downlink communications. uplink, and so on. In other words, the downlink/uplink switching detection component 512 may continue to detect the switching of downlink to uplink communications in the configurable TTIs and of uplink to downlink communications to synchronize communications with the eNB 504 using the techniques described above.

[0086] Figure 8 illustrates an exemplary method 800 for determining (e.g., via a UE) whether a configurable TTI can be configured for uplink and downlink communications. In Block 802, the UE may monitor one or more configurable TTIs for one or more reference signals. The reference signal monitoring component 514 may monitor the one or more configurable TTIs for the one or more reference signals. As described, for example, the reference signal monitoring component 514 may monitor a pilot signal and/or one or more pilot sequences known to correspond to a reference signal. In one example, the reference signal monitoring component 514 may receive a pilot signal (e.g., from the eNB 504) in a previous TTI (e.g., according to a dense or sparse pilot configuration), and may use the pilot signal to detect similar reference signals received in subsequent TTIs. The reference signal monitoring component 514 may thus determine a pilot sequence for one or more reference signals transmitted by NB 504, and may use the pilot sequence to attempt coherent detection of one or more reference signals in subsequent configurable TTIs. In another example, the reference signal monitoring component 514 may non-coherently detect reference signals in a TTI without detecting similar reference signals in previous TTIs.

[0087] In Block 804, the UE may determine the possibility of one or more reference signals being detected in a TTI. The reference signal monitoring component 514 may determine the possibility of one or more reference signals being detected in the TTI. As described, this may be based on checking a pilot sequence of reference signals, performing channel estimation to determine which signals are reference signals, etc.

[0088] When one or more reference signals are detected in the TTI at Block 804, at Block 806, the UE may determine that the configurable TTI is configured for downlink communications. The downlink/uplink switching detection component 512 may determine that the TTI is configured for downlink communications when one or more reference signals are detected in the TTI. Reference signals may correspond to downlink reference signals, such as CRS, as described above. Accordingly, in Block 808, the UE may receive downlink communications during the configurable TTI. The communication component 361 may receive downlink communications (e.g., from the eNB 504) during the configurable TTI. It should be understood that when transceiver 506 is configured for uplink communications where one or more reference signals are detected at 804, receiving downlink communications at Block 808 may also include communications component 361 that switches transceiver 506 and/or related resources. (e.g., a modem processor, an antenna, etc.) to receive downlink signals during TTI.

[0089] When one or more reference signals are not detected in the TTI at Block 804, at Block 810 the UE may determine that the configurable TTI is configured for uplink communications. The downlink/uplink switching detection component 512 may determine that the TTI is configured for uplink communications when one or more reference signals are detected in the TTI. Accordingly, in Block 812, the UE may transmit uplink communications during the configurable TTI, or in Block 814, it may enter a sleep mode during one or more TTIs. Communication component 361 may transmit uplink communications during the configurable TTI and/or enter sleep mode during one or more TTIs. For example, the transmission of uplink communications in Block 812 may include communication component 361 that transmits uplink control communications (e.g., ACK/NACK, CSI, SR, etc., which may be transmitted via semi-statically assigned resources) at least in the first configurable TTI determined to be configured for uplink communications. Furthermore, in one example, entering sleep mode in Block 804 may include suspending or disabling one or more resources of the UE 502 (e.g., transceiver 506 or components thereof, a modem processor, an antenna, etc.) during one or more TTIs. For example, this may occur when a TTI is determined to be configured for uplink communications, and the UE 502 has not received an uplink resource grant or has terminated transmission to the eNB 504, etc. It should be understood that when transceiver 506 is configured for downlink communications in which one or more reference signals are not detected in 804, transmission of downlink communications in Block 812 and/or entry into sleep mode in Block 814 may also include the communication component 361 that switches transceiver 506 and/or related resources (e.g., a modem processor, antenna, etc.) to transmit uplink signals during TTI.

[0090] In either case, method 800 may proceed from Block 808 or 812/814 to Block 802 to continue monitoring the configurable TTIs for one or more reference signals to determine the possibility of the configurable TTIs being configured for uplink communications and downlink.

[0091] Figure 9 illustrates an exemplary method 900 for indicating (e.g., via an eNB) a switch between downlink and uplink communications for one or more configurable TTIs. In Block 902, the eNB may communicate with the UE using a frame structure that allows dynamic switching of configurable TTIs between uplink and downlink communications within the frame. The programming component 302 (Figure 5) may communicate with the UE (e.g., the UE 502) using the frame structure that allows dynamic switching of configurable TTIs between uplink and downlink communications within the frame. In one example, the resource grant generation component 520 may configure the UE 502 with designated resources based on the frame structure, as described, which the programming component 302 may use to transmit and/or receive communications to/from the UE 502. Additionally, For example, programming component 302 may transmit downlink reference signals or other signals through configurable TTIs configured for downlink communications, dedicated downlink TTIs, etc. In one example, the frame structure may be similar to frame structure 400 (Figure 4), which includes dedicated downlink TTIs, configurable TTIs for both uplink and downlink communications, and/or dedicated uplink TTIs.

[0092] In Block 904, the eNB may determine the switching of a configurable TTI from downlink to uplink communications. The programming component 302 may determine the switching of the configurable TTI from downlink to uplink communications. As described, for example, the programming component 302 may determine the switching of configurable TTIs from downlink to uplink communications based, at least in part, on one or more parameters of the eNB 504, such as parameters indicative of a load on the eNB 504, delay requirements for packets on the eNB 504, etc., one or more parameters of the UE 502, such as parameters indicative of a temporary storage situation, quality of service, subscription level, etc. of the UE 502, one or more parameters regarding a time interval over which it switches between downlink and uplink communications, delay requirements for packets in the UE 502, etc., and/or the like. Thus, for example, programming component 302 may determine the switching of configurable TTIs from downlink to uplink communications and/or vice versa to achieve a desired downlink or uplink latency. In another example, the eNB 504 may receive instructions from one or more network components and/or a request (e.g., SR) from a UE, such as the UE 502, to switch from downlink to uplink communications.

[0093] In Block 906, the UE may transmit a switching indication to the UE. The downlink/uplink switching indication component 522 may transmit the switching indication to the UE (e.g., the UE 502). For example, the switching may include an explicit or implicit indicator as described above (e.g., a resource grant or other indicator 580, one or more reference signals, etc.). In an example, when transmitting the switching indication in Block 906, in Block 908, the eNB may optionally transmit the indication in an uplink resource grant to the UE. The resource grant generation component 520 may generate an uplink resource grant to the UE 502 including the indication, and thus the programming component 302 may transmit the indication in the uplink resource grant to the UE 502. Consequently, for example, the receipt of the uplink resource grant may indicate when the switch should occur (e.g., an explicit indication of the TTI at which the switch should then occur, numerous TTIs indicated or known after receipt of the grant, etc.). In another example, as described, the transmission of the indication in Block 906 may include the programming component 302 transmitting another indicator to the UE 502 (for example, a switching warning indicator). In this sense, for example, the indicator may indicate that a switch to uplink communications should occur at a next configurable TTI, and/or may explicitly indicate a subsequent TTI at which the switch should occur.

[0094] In Block 912, the eNB may optionally determine the switching of a configurable TTI from uplink to downlink communications. The programming component 302 may determine the switching of the configurable TTI from uplink to downlink communications. As described, for example, the programming component 302 may determine the switching of the configurable TTIs from downlink to uplink communications based, at least in part, on one or more parameters of the eNB 504 in order to achieve a desired uplink and/or downlink latency, etc.

[0095] In Block 914, the UE may transmit a switching indication to the UE. The programming component 302 may transmit the switching indication to the UE 502. As described, for example, the indication transmitted in the uplink resource grant or other indicator 580 may also include an indication of when the TTIs will be switched back to downlink communications. For example, the indication may include an uplink resource grant size, which may indicate that a switch back to downlink communications should occur after the uplink resource grant, or another indication of a switch back to downlink communications (e.g., a index of the TTI during which switching must occur, number of TTIs after which switching must occur, etc.), as described. Similarly, for unscheduled UEs (and/or scheduled UEs in another example), uplink and downlink switching indication component 522 may generate the other indicator (e.g., a warning indicator) that identifies when a switch to uplink communications should occur. Furthermore, in one example, the indicator may also specify a burst length of an uplink data burst, an index of the TTI during which switching should occur, etc., so that a TTI at which a switch back to communications downlink must occur in order to be identified.

[0096] In another example, as described, the programming component 302 may transmit downlink reference signals and/or downlink grants (generated by resource grant generation component 520) when the programming component 302 determines the switching of the configurable TTIs for communications downlink. This may occur without explicit notification to the UE 502 and/or other UEs. The UE 502 can therefore determine switching by detecting the receipt of reference signals, decoding one or more control channels based on the reference signal, etc., as described above. Accordingly, in one example, when transmitting the switching indication to the UE at Block 914, at Block 916, the UE may transmit a dense pilot signal with CRS to indicate a downlink TTI. The programming component 302 may transmit the dense pilot signal with the CRS to indicate the downlink TTI. For example, the programming component 302 may transmit the dense pilot signal using a plurality of subcarriers (e.g., all subcarriers available in a bandwidth used by the UE 502 to communicate with the eNB 504), which may occur at the first TTI of a continuous trigger. downlink, to facilitate enhanced reception and detection by the UE 502. This may assist the UE 502 in performing an initial channel estimate of one or more CRSs based on the dense pilot signal to determine the CRS pilot sequence, as described above, to subsequently determine the possibility that the CRS is present in one or more configurable TTIs to detect a switch to downlink communications.

[0097] Figure 10 illustrates an example of a communication timeline 1000 that has TTIs configured for uplink and downlink communications in dynamic TDD frame structures (e.g., frame structure 400 in Figure 4), as described herein. Timeline 1000 may be used for communication between a UE 502 and an eNB 504, as described above. For example, and in some cases, timeline 1000 includes signals such as uplink signals 508 and/or downlink signals 509. Pilot transmissions shown in timeline 1000 may be used by UE 502 (e.g., with the use of monitoring component reference signal 514) to determine the possibility of a TTI being configured for uplink and downlink communications (e.g., and/or the possibility of communications being switched from an uplink continuous shot to a downlink continuous shot, or vice versa, in TTI), as described.

[0098] Timeline 1000 may include continuous downlink triggering (DL) 1005-a along one or more TTIs, as described, which may be configured or dedicated for downlink communications. DL continuous firing 1005-a may include preamble DL symbols 1010-a and regular DL symbols 1015-a. In some examples, the regular DL symbols 1015-a may include regular pilot signals (e.g., CRS or other reference signals) and the preamble DL symbol 1010-a may include a dense pilot signal (e.g., a plurality of built-in reference signal tones, such as as CRS tones, in a usable bandwidth as described). A dense pilot may be sent at the beginning of continuous firing of DL 1005-a to facilitate improved baseline channel estimation in UE 502 as described. The timeline 1000 may also include a second continuous shot of DL 1005-b which, in some cases, may be sent in prior signaling to the UE 502 (e.g., without an explicit indication that the configurable TTI is switched to downlink communications). DL 1005-b continuous firing may include a preamble DL symbol 1010-b and regular pilot symbols 1015-b, in a similar manner to DL 1005-a continuous firing. Timeline 1000 may also include UL continuous trigger 420-a and UL continuous trigger 420-b, which may relate to a UE (e.g., UE 502) that transmits uplink signals 508 to the eNB 504 based on a link resource grant. upstream provided to the UE. The continuous trigger of DL 405-b may be received subsequent to a continuous trigger of UL (e.g., continuous trigger of UL 420-a), or it may be received immediately after the continuous trigger of DL 405-a (not shown).

[0099] Regardless of the reception order, a UE 502 (e.g., downlink/uplink switching detection component 512) may determine whether a TTI is configured for uplink and downlink communications based, at least in part, on a detection of a pilot signal (e.g., reference signal) whose pilot sequence is known (e.g., based on a previous configuration or observation of the reference signal). For example, the preamble DL symbol 1010-a may include CRS, the presence of which may indicate to a UE 502 that the continuous firing of DL 1005-a is a continuous firing of DL. In some examples, a UE 502 (e.g., downlink/uplink switching detection component 512) may confirm blind trigger detection of DL 1010-a by decoding a known physical layer channel (e.g., PDCCH, PCFICH, etc.). UL 1020-a continuous triggering may not include a reference signal whose pilot sequence is known (e.g., CRS). Thus, the UE 502 can detect an absence of the reference signal (e.g., based on the absence of the pilot sequence) and determine that the continuous trigger of UL 1020-a is a continuous trigger of UL (and thus the related TTI is an uplink TTI).

[0100] Figure 11 illustrates an example DL continuous firing pilot pattern 1100 that includes an expanded view of regular DL symbols 1115-c for blind detection of the possibility of a TTI being configured for uplink and downlink communications in frame structures. of dynamic TDD (e.g., frame structure 400 in Figure 4), as described in this document. DL 1105-c continuous shooting may be used for communications between a UE 502 and an eNB 504, as described above, and may be an aspect of DL 1005-a continuous shooting and DL 1005-b continuous shooting, as described in reference to Figure 10.

[0101] The DL 1100 continuous firing pilot pattern may include an example of DL 1105-c continuous firing time and frequency resource elements that represent exemplary locations of pilot tones 1125. For example, the pilot tones for the first antenna may be transmitted in regularly spaced tones (every 25 tones in this example) in each TTI (e.g. symbol), where the index (offset) of the pilot tone can be changed by a certain amount (3 tones in this example) for each symbol. The pattern can be repeated every N symbols, where N is a positive integer (for example, 25 symbols in this example). Pilots for different transmitting antennas can be transmitted at different tone locations. The DL 1102 continuous fire pilot pattern represents a possible pattern for pilot transmission in a DL 1 105 continuous fire, but other pilot patterns may also be used.

[0102] In one example, a UE 502 may monitor a wireless channel of an eNB 504 for a pilot transmission (e.g., as part of the DL 1100 continuous firing pilot pattern). In some cases, the UE 502 (e.g., reference signal monitoring component 514) may detect a pilot sequence and may determine (e.g., via downlink/uplink switching detection component 512) that the transmission is a DL transmission (e.g., , continuous firing of DL 1105-c) and, thus, that the corresponding TTI is configured for downlink communications. The downlink/uplink switching detection component 512 may also verify that the TTI is configured for downlink communications by decoding a known physical layer DL channel in the TTI or a subsequent TTI (e.g., based on the reference signal that corresponds to the pilot sequence). In another example, the downlink/uplink switching detection component 512 may identify an absence of a pilot sequence on the wireless channel during the TTI and may determine that the TTI is not configured for downlink communications (e.g., that the TTI is configured for downlink communications). uplink).

[0103] It is understood that the specific hierarchy or order of steps in the revealed processes is an illustration of exemplary approaches. Based on project preferences, it is understood that the specific hierarchy of steps in the processes can be reorganized. Additionally, some steps can be combined or omitted. The accompanying method claims the present elements of the various steps in a sample order, and is not intended to be limited to the specific order or hierarchy presented.

[0104] The foregoing description is provided to enable any person skilled in the art to practice the various aspects described in this document. Various modifications to these aspects will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other aspects. Accordingly, the claims are not intended to be limited to the aspects set forth herein, but must conform to the full scope consistent with the language of the claims, wherein reference to an element in the singular is not intended to mean “one and only one” unless specifically so set forth. but instead “one or more.” Unless otherwise stated, the term “any” refers to one or more. All functional and structural equivalents to the elements of the various aspects described herein, which are known or will subsequently become known by individuals of ordinary skill in the art, are expressly incorporated herein by reference and are intended to be covered by the claims. Furthermore, nothing disclosed in this document is intended to be dedicated to the public, regardless of whether such disclosure is explicitly cited in the claims. No claiming element should be interpreted as a means plus function unless the element is expressly cited using the phrase “means to”.

Claims (15)

1. Method for communication that uses dynamic transmission time interval (TTI) switching of uplink and downlink in a wireless network, characterized in that it comprises: receiving (604) a notification from a network entity to switch a configurable TTI from downlink communications to uplink communications, wherein the configurable TTI is one of a plurality of TTIs in a frame structure that allows dynamic switching of configurable TTIs between downlink and uplink communications within a frame; and transmitting (616) uplink communications to the network entity during the configurable TTI based, at least in part, on the notification. 2. Method according to claim 1, characterized by the fact that the transmission (616) comprises transmitting control data to the network entity in the configurable TTI. 3. The method of claim 2, wherein the control data includes one or more acknowledgment or non-acknowledgement indicators, channel state information reports, or scheduling requests. 4. The method of claim 1, further comprising transmitting uplink communications to the network entity during one or more subsequent configurable TTIs configured for uplink communications in an uplink continuous shot. based, at least in part, on the notification. 5. The method of claim 4, wherein the notification includes an uplink resource grant that indicates an uplink continuous shot length before switching a subsequent configurable TTI for downlink communications to a downlink continuous shot. 6. The method of claim 1, wherein the notification includes a bit in a prior TTI configured for downlink communications, wherein the bit indicates that a subsequent configurable TTI is to be configured for uplink communications and/or that a plurality of subsequent configurable TTIs are configured for uplink communications for a continuous shot of uplink data. 7. The method of claim 1, further comprising: determining a first configurable TTI to be switched for downlink communications for a next downlink continuous shot based, at least in part, on nanonotification; and receiving control data from the network entity in the first configurable TTI. 8. The method of claim 1, further comprising determining a first configurable TTI to be switched for downlink communications for a next downlink burst based, at least in part, on a burst length of one uplink data burst related to the configurable TTI, wherein the burst length is specified in an uplink resource grant related to the configurable TTI. 9. The method of claim 1, further comprising: monitoring network entity signals in one or more configurable TTIs following the configurable TTI through which uplink communications are transmitted; and determining switching the one or more configurable TTIs back to downlink communications based, at least in part, on at least one of detecting a downlink reference signal on the one or more configurable TTIs after the configurable TTI or decoding a control channel. downlink based, at least in part, on the detection of the downlink reference signal. 10. The method of claim 1, further comprising: monitoring network entity signals on one or more configurable TTIs after transmitting uplink communications on a plurality of configurable TTIs; and determining the switching of the one or more configurable TTIs back to downlink communications based, at least in part, on the detection of a downlink reference signal in the configurable TTIs after transmission of uplink communications in the plurality of configurable TTIs. 11. The method of claim 1, wherein receiving the notification comprises: determining (614) that a prior configurable TTI is configured for downlink communications based, at least in part, on detecting (610) one or more reference signals in the previous configurable TTI; and determining that the configurable TTI is configured for uplink communications based, at least in part, on detecting (612) that the configurable TTI does not include the one or more reference signals. 12. Method for communicating using transmission time slot, TTI, uplink and downlink switching in a wireless network, characterized by the fact that it comprises: transmitting (906) a notification to a user equipment, UE, of switching a configurable TTI to downlink communications to uplink communications, wherein the configurable TTI is one of a plurality of TTIs in a frame structure that allows dynamic switching of configurable TTIs between downlink and uplink communications within a frame; and receiving uplink communications from a UE during the configurable TTI based on at least part of the notification. 13. User equipment for communication, which uses dynamic transmission time interval switching, TTI, uplink and downlink, in a wireless network, characterized by the fact that it comprises: means for receiving (604) a notification from a network entity to switching a configurable TTI from downlink communications to uplink communications, wherein the configurable TTI is one of a plurality of TTIs in a frame structure that allows dynamic switching of configurable TTIs between downlink and uplink communications within a frame; and means for transmitting (616) uplink communications to the network entity during the configurable TTI based on, at least in part, nanonotification. 14. Network unit for communication using transmission time slot, TTI, uplink and downlink switching in a wireless network, characterized by the fact that it comprises: means for transmitting (906) a notification to a user equipment, UE, of switching a configurable TTI from downlink communications to uplink communications, wherein the configurable TTI is one of a plurality of TTIs in a frame structure that allows dynamic switching of configurable TTIs between downlink and uplink communications within a frame; and means for receiving uplink communications from the UE during the configurable TTI based on at least one part of the notification. 15. Computer-readable memory, characterized by the fact that it has instructions stored therein that, when executed, cause at least one computer to perform the method as defined in any one of claims 1 to 12.