Patent Description:
The present disclosure relates generally to communication systems, and more particularly, to a downlink frame structure and method of downlink transmission for managing communications with one or more user equipment (UE) in a wireless communications system.

Wireless communications systems are widely deployed to provide various telecommunication services such as telephony, video, data, messaging, and broadcasts. Typical wireless communications systems may employ multiple-access technologies capable of supporting communication with multiple users by sharing available system resources (e.g., bandwidth, transmit power).

An example of an emerging telecommunication standard is Long Term Evolution (LTE). LTE is a set of enhancements to the Universal Mobile Telecommunications System (UMTS) mobile standard promulgated by Third Generation Partnership Project (3GPP). It is designed to better support mobile broadband Internet access by improving spectral efficiency, lower costs, improve services, make use of new spectrum, and better integrate with other open standards using OFDMA on the downlink (DL), SC-FDMA on the uplink (UL), and multiple-input multiple-output (MIMO) antenna technology. However, as the demand for mobile broadband access continues to increase, there exists a need for further improvements in LTE technology. Preferably, these improvements should be applicable to other multiaccess technologies and the telecommunication standards that employ these technologies.

In wireless communications systems employing legacy LTE, a plurality of UEs served by a particular eNodeB may receive data from the eNodeB over a shared downlink channel called the Physical Downlink Shared Channel (PDSCH). In addition, control information associated with the PDSCH or may be transmitted to the UEs by the eNodeB via a Physical Downlink Control Channel (PDCCH) and/or an Enhanced PDCCH (ePDCCH). The control information included in the PDCCH or ePDCCH may include one or more uplink or downlink resource element (RE) grants for an LTE subframe. In legacy LTE, each LTE subframe has a transmission time interval (TTI) of <NUM> and is divided into two <NUM> slots. Any RE grants transmitted on the PDCCH, however, are for a remaining duration of the entire subframe (i.e., the full remainder of <NUM>). As such, legacy LTE does not allow for resource scheduling at a level of granularity less than a full <NUM> LTE subframe, even if faster downlink communication rates are desired for a particular communication flow.

As such, improvements in the downlink frame structure and downlink transmission methods are needed. Relatedly, document <CIT> describes an extensible and scalable control channel for wireless networks, and document 3GPP R1-<NUM> describes a concept of E-PDCCH CCE.

In accordance with one or more aspects and corresponding disclosure thereof, various techniques are described in connection with example data structures, methods, and apparatuses for improving wireless communication speed and reliability between one or more UEs and network entities in wireless communication networks. Embodiments and aspects that do not fall within the scope of the claims are merely examples used for explanation of the invention.

For instance, in an aspect of the present disclosure, an example data structure for managing user equipment communications in a wireless communications system is described. The example data structure may include a downlink subframe comprising two slots and including one or more quick downlink channels having a single-slot TTI. Additionally, the example data structure may include one or more resource element blocks each comprising one or more resource elements into which a frequency bandwidth is divided within one or both of the two slots, wherein each of the one or more resource element blocks comprises a control channel region or a data channel region. Furthermore, the example data structure may include one or more resource grants, located within one or more control channel regions, for one or more user equipment served by the one or more quick downlink channels.

In a further aspect, the present disclosure presents an example method of managing UE communications in a wireless communications system, and may include obtaining, at a network entity, user data for transmission to one or more user equipment UEs on a downlink channel. The example method may further include determining one or more delivery constraints associated with at least one of the user data and the one or more UEs. Moreover, the example method may include generating, based on the user data for transmission and the one or more delivery constraints, a downlink subframe data structure for allocating downlink channel resources for transmission of the user data for transmission. In the example method, the downlink subframe data structure may include a downlink subframe comprising two slots and including one or more quick downlink channels having a single-slot TTI. Furthermore, the example downlink subframe data structure may further include one or more resource element blocks each comprising one or more resource elements into which a frequency bandwidth is divided within one or both of the two slots, wherein each of the one or more resource element blocks comprises a control channel region or a data channel region and one or more resource grants, located within one or more control channel regions, for the one or more UEs served by the one or more quick downlink channels.

Moreover, the present disclosure describes an example apparatus for managing UE communications in a wireless communications system, and may include means for obtaining, at a network entity, user data for transmission to one or more user equipment UEs on a downlink channel. The example apparatus may further include means for determining one or more delivery constraints associated with at least one of the user data and the one or more UEs. Moreover, the example apparatus may include means for generating, based on the user data for transmission and the one or more delivery constraints, a downlink subframe data structure for allocating downlink channel resources for transmission of the user data for transmission. In the example apparatus, the downlink subframe data structure may include a downlink subframe comprising two slots and including one or more quick downlink channels having a single-slot TTI. Furthermore, the example downlink subframe data structure may further include one or more resource element blocks each comprising one or more resource elements into which a frequency bandwidth is divided within one or both of the two slots, wherein each of the one or more resource element blocks comprises a control channel region or a data channel region and one or more resource grants, located within one or more control channel regions, for the one or more UEs served by the one or more quick downlink channels.

In an additional aspect, an example apparatus for managing UE communications in a wireless communications system is presented, which may include a processor and a memory coupled to the processor. In some examples, the memory may store processor-executable instructions, that when executed by the processor, cause the processor to obtain, at a network entity, user data for transmission to one or more UEs on a downlink channel. Additionally, the memory may store processor-executable instructions, that when executed by the processor, cause the processor to determine one or more delivery constraints associated with at least one of the user data and the one or more UEs. In addition, the memory may store processor-executable instructions, that when executed by the processor, cause the processor to generate, based on the user data for transmission and the one or more delivery constraints, a downlink subframe data structure for allocating downlink channel resources for transmission of the user data for transmission. According to the example apparatus, the downlink subframe data structure may include a downlink subframe comprising two slots and including one or more quick downlink channels having a single-slot TTI. In addition, the downlink subframe data structure may include one or more resource element blocks each comprising one or more resource elements into which a frequency bandwidth is divided within one or both of the two slots, wherein each of the one or more resource element blocks comprises a control channel region or a data channel region. Furthermore, the downlink subframe data structure may include one or more resource grants, located within one or more control channel regions, for the one or more UEs served by the one or more quick downlink channels.

Moreover, the disclosure presents an example computer-readable medium storing computer-executable code for managing UE communications in a wireless communications system. In an aspect, the computer-executable code may include code for obtaining, at a network entity, user data for transmission to one or more user equipment UEs on a downlink channel. In addition, the computer-executable code may include code for determining one or more delivery constraints associated with at least one of the user data and the one or more UEs. Furthermore, the computer-executable code may include code for generating, based on the user data for transmission and the one or more delivery constraints, a downlink subframe data structure for allocating downlink channel resources for transmission of the user data for transmission. According to the example computer-readable medium, the downlink subframe data structure may include a downlink subframe comprising two slots and including one or more quick downlink channels having a single-slot TTI. The downlink subframe data structure may also include one or more resource element blocks each comprising one or more resource elements into which a frequency bandwidth is divided within one or both of the two slots, wherein each of the one or more resource element blocks comprises a control channel region or a data channel region. Additionally, the downlink subframe data structure may include one or more resource grants, located within one or more control channel regions, for the one or more UEs served by the one or more quick downlink channels.

These apparatus and methods will be described in the following detailed description and illustrated in the accompanying drawings by various blocks, modules, components, circuits, steps, processes, algorithms, etc. (collectively referred to as "elements").

Accordingly, in one or more aspects, the functions described may be implemented in hardware, software, firmware, or any combination thereof. By way of example, and not limitation, such computer-readable media can 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 desired program code in the form of instructions or data structures and that can be accessed by a computer. Disk and disc, as used herein, includes compact disc (CD), laser disc, optical disc, digital versatile disc (DVD), and floppy disk where disks usually reproduce data magnetically, while discs reproduce data optically with lasers.

The present disclosure presents example data structures and transmission methods for managing downlink communications to one or more UEs, and in particular, to reduce latency as compared to legacy downlink data structures and downlink transmission methods. These data structures of the present disclosure may include one or more resource element blocks into which a frequency bandwidth of one or more downlink channels is divided within a slot of an LTE subframe. Likewise, any REs of the subframe may have an assignment that lasts for a single slot in the subframe or for the entire subframe.

In addition, any of the resource element blocks of a particular slot may comprise a control channel region or a data channel region. A control channel region may include one or more resource grants associated with one or more UEs served by a network entity (e.g., an eNodeB). Such resource grants may include one or more downlink resource grants and/or one or more uplink resource grants. For example, in one aspect of the present disclosure, a control channel region located in the first symbol (or first few symbols) of a subframe may be utilized for scheduling downlink frequency grants in data channel region that comprises the remainder of the first slot of the subframe or for the remainder of the entire subframe. For purposes of the present disclosure, the control channel corresponding to such a control channel region may be referred to as a Quick Physical Downlink Control Channel (QPDCCH).

In another aspect of the present disclosure, a control channel region may include a resource element block spanning an entire single slot (or a portion thereof) and may be utilized for scheduling downlink frequency grants for one or more other resource element blocks in the same slot. For purposes of the present disclosure, the control channel corresponding to such a control channel region may be referred to as a Quick Enhanced Physical Downlink Control Channel (QEPDCCH).

Furthermore, a data channel region of the present disclosure may include a resource element block spanning an entire single slot (or a portion thereof) during which user data is transmitted to a UE receiving a downlink grant in a control channel region (e.g., corresponding to a QPDCCH or a QEPDCCH). For purposes of the present disclosure, the data channel corresponding to such a data channel region may be referred to as a Quick Physical Downlink Shared Channel (QPDSCH).

Additionally, for purposes of the present disclosure, any channel that may have a temporal length (e.g., TTI) of a single slot (or a portion of a single slot) or includes resource grants for a data channel having a temporal length of a single slot (or a portion of a single slot) may be referred to herein as a "Quick LTE channel. " These Quick LTE channels may include, in a non-limiting aspect, a QPDCCH, a QEPDCCH, and a QPDSCH. Furthermore, any reference to "Quick LTE" in the present disclosure may refer to a data structure for resource element scheduling (or a method or apparatus implementing the data structure) having one or more channels or resource element blocks that are or can be allocated, assigned, or divided on a per-slot basis and/or have a TTI of <NUM>. Such references to Quick LTE may include "Quick LTE scheduling," "Quick LTE scheme," or the like.

Moreover, the example data structures of the present disclosure are configured to additionally implement frame scheduling of legacy LTE channels (e.g., PDCCH, EPDCCH, PDSCH) alongside the slot-specific RE allocation aspects introduced by the present disclosure for corresponding Quick LTE channels (e.g., QPDCCH, QEPDCCH, QPDSCH). In this way, the data structures described herein may be implemented for UEs or specific UE applications that are configured to utilize Quick LTE scheduling (per-slot scheduling) and/or legacy LTE scheduling (persubframe scheduling). As the Quick LTE scheduling methods described herein may utilize a <NUM> TTI rather than the <NUM> TTI of legacy LTE, these methods may increase communication rates two-fold and may cut a round-trip time (RTT) associated with legacy LTE hybrid automatic repeat request (HARQ) procedures in half (e.g., from <NUM> to <NUM> or less).

In an additional aspect of the present disclosure, a network entity (e.g., an eNodeB) is presented, which may be configured to manage downlink scheduling by generating one or more of the data structures disclosed herein. Furthermore, the network entity may be configured to obtain data for transmission to one or more UEs and may schedule the transmission of the data using the data structure based on the data and/or delivery constraints associated with the one or more UEs.

Referring first to <FIG>, a diagram illustrates an example of a wireless communications system <NUM>, in accordance with an aspect of the present disclosure. The wireless communications system <NUM> includes a plurality of access points (e.g., base stations, eNBs, or WLAN access points) <NUM>, a number of user equipment (UEs) <NUM>, and a core network <NUM>. Access points <NUM> may include a downlink scheduling component <NUM> configured to expedite communication of control information and user data with the number of UEs <NUM> using an Quick LTE data structure, for example but not limited to data structure <NUM> of <FIG>, below, which may include a TTI of one slot for some RE blocks. For example, the Quick LTE data structure may include one or more resource element blocks for allocating a PDCCH, EPDCCH, PDSCH, QPDCCH, QEPDCCH, and/or QPDSCH. Similarly, one or more of UEs <NUM> may include a downlink management component <NUM> configured to receive, decode and operate using the data structure. Some of the access points <NUM> may communicate with the UEs <NUM> under the control of a base station controller (not shown), which may be part of the core network <NUM> or the certain access points <NUM> (e.g., base stations or eNBs) in various examples. Access points <NUM> may communicate control information and/or user data with the core network <NUM> through backhaul links <NUM>. In examples, the access points <NUM> may communicate, either directly or indirectly, with each other over backhaul links <NUM>, which may be wired or wireless communication links. The wireless communications system <NUM> may support operation on multiple carriers (waveform signals of different frequencies). Multi-carrier transmitters can transmit modulated signals simultaneously on the multiple carriers. For example, each communication link <NUM> may be a multi-carrier signal modulated according to 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.), overhead information, data, etc..

In some examples, at least a portion of the wireless communications system <NUM> may be configured to operate on multiple hierarchical layers in which one or more of the UEs <NUM> and one or more of the access points <NUM> may be configured to support transmissions on a hierarchical layer that has a reduced latency with respect to another hierarchical layer. In some examples a hybrid UE <NUM>-a may communicate with access point <NUM>-a on 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 <NUM>-a may transmit subframes of the second subframe type that are time division duplexed with subframes of the first subframe type.

In some examples, hybrid UE <NUM>-a may acknowledge receipt of a transmission by providing ACK/NACK for the transmission through, for example, a HARQ scheme. Acknowledgments from hybrid UE <NUM>-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 <NUM>-a, when operating in the second hierarchical layer may, in examples, acknowledge receipt in a 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 referred to as round trip time (RTT), and thus subframes of the second subframe type may have a second RTT that is shorter than a RTT for subframes of the first subframe type.

In other examples, a second layer UE <NUM>-b may communicate with access point <NUM>-b on the second hierarchical layer only. Thus, hybrid UE <NUM>-a and second layer UE <NUM>-b may belong to a second class of UEs <NUM> that may communicate on the second hierarchical layer, while legacy UEs <NUM> may belong to a first class of UEs <NUM> that may communicate on the first hierarchical layer only. Access point <NUM>-b and UE <NUM>-b may communicate on the second hierarchical layer through transmissions of subframes of the second subframe type. Access point <NUM>-b may transmit subframes of the second subframe type exclusively, or may transmit one or more subframes of the first subframe type on the first hierarchical layer that are time division multiplexed with subframes of the second subframe type. Second layer UE <NUM>-b, in the event that access point <NUM>-b transmits subframes of the first subframe type, may ignore such subframes of the first subframe type. Thus, second layer UE <NUM>-b may acknowledge receipt of transmissions in a same subframe as the subframe in which the transmissions are received. Thus, second layer UE <NUM>-b may operate with reduced latency compared to UEs <NUM> that operate on the first hierarchical layer.

The access points <NUM> may wirelessly communicate with the UEs <NUM> via one or more access point antennas. Each of the access points <NUM> sites may provide communication coverage for a respective coverage area <NUM>. In some examples, access points <NUM> 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 NodeB, eNodeB, Home NodeB, a Home eNodeB, or some other suitable terminology. The coverage area <NUM> for a base station may be divided into sectors making up only a portion of the coverage area (not shown). The wireless communications system <NUM> may include access points <NUM> of different types (e.g., macro, micro, and/or pico base stations). The access points <NUM> may also utilize different radio technologies, such as cellular and/or WLAN radio access technologies. The access points <NUM> may be associated with the same or different access networks or operator deployments. The coverage areas of different access points <NUM>, including the coverage areas of the same or different types of access points <NUM>, utilizing the same or different radio technologies, and/or belonging to the same or different access networks, may overlap.

In LTE/LTE-A network communication systems, the terms evolved Node B (eNodeB or eNB) may be generally used to describe the access points <NUM>. The wireless communications system <NUM> may be a Heterogeneous LTE/LTE-A/ULL LTE network in which different types of access points provide coverage for various geographical regions. For example, each access point <NUM> may provide communication coverage for a macro cell, a pico cell, a femto cell, and/or other types of cell. Small cells such as pico cells, femto cells, and/or other types of cells may include low power nodes or LPNs. A small cell would generally cover a relatively smaller geographic area and may allow unrestricted access by UEs <NUM> with service subscriptions with the network provider, for example, and in addition to unrestricted access, may also provide restricted access by UEs <NUM> having an association with the small cell (e.g., UEs in a closed subscriber group (CSG), UEs for users in the home, and the like). An eNB for a small cell may be referred to as a small cell eNB. An eNB may support one or multiple (e.g., two, three, four, and the like) cells.

The core network <NUM> may communicate with the eNBs or other access points <NUM> via a backhaul <NUM> (e.g., S1 interface, etc.). The access points <NUM> may also communicate with one another, e.g., directly or indirectly via backhaul links <NUM> (e.g., X2 interface, etc.) and/or via backhaul links <NUM> (e.g., through core network <NUM>). The wireless communications system <NUM> may support synchronous or asynchronous operation. For synchronous operation, the access points <NUM> may have similar frame timing, and transmissions from different access points <NUM> may be approximately aligned in time. For asynchronous operation, the access points <NUM> may have different frame timing, and transmissions from different access points <NUM> may not be aligned in time. Furthermore, transmissions in the first hierarchical layer and second hierarchical layer may or may not be synchronized among access points <NUM>.

The UEs <NUM> are dispersed throughout the wireless communications system <NUM>, and each UE <NUM> may be stationary or mobile. A UE <NUM> 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 <NUM> may be a cellular phone, a personal digital assistant (PDA), a wireless modem, a wireless communication device, a handheld device, a tablet computer, a laptop computer, a cordless phone, a wearable item such as a watch or glasses, a wireless local loop (WLL) station, or the like. A UE <NUM> may be able to communicate with macro eNodeBs, small cell eNodeBs, relays, and the like. A UE <NUM> may also be able to communicate over different access networks, such as cellular or other WWAN access networks, or WLAN access networks.

The communication links <NUM> shown in wireless communications system <NUM> may include uplink (UL) transmissions from a UE <NUM> to an access point <NUM>, and/or downlink (DL) transmissions, from an access point <NUM> to a UE <NUM>. The downlink transmissions may also be called forward link transmissions while the uplink transmissions may also be called reverse link transmissions. The communication links <NUM> may carry transmissions of each hierarchical layer which, in some examples, may be multiplexed in the communication links <NUM>. The UEs <NUM> may be configured to collaboratively communicate with multiple access points <NUM> through, for example, Multiple Input Multiple Output (MIMO), carrier aggregation (CA), Coordinated Multi-Point (CoMP), or other schemes. MIMO techniques use multiple antennas on the access points <NUM> and/or multiple antennas on the UEs <NUM> to transmit multiple data streams. Carrier aggregation may utilize two or more component carriers on a same or different serving cell for data transmission. CoMP may include techniques for coordination of transmission and reception by a number of access points <NUM> to improve overall transmission quality for UEs <NUM> as well as increasing network and spectrum utilization.

As mentioned, in some examples access points <NUM> and UEs <NUM> may utilize carrier aggregation to transmit on multiple carriers. In some examples, access points <NUM> and UEs <NUM> may concurrently transmit in a first hierarchical layer, within a frame, one or more subframes each having a first subframe type using two or more separate carriers. Each carrier may have a bandwidth of, for example, <NUM>, although other bandwidths may be utilized. Hybrid UE <NUM>-a, and/or second layer UE <NUM>-b may, in certain examples, receive and/or transmit one or more subframes in a second hierarchical layer utilizing a single carrier that has a bandwidth greater than a bandwidth of one or more of the separate carriers. For example, if four separate <NUM> carriers are used in a carrier aggregation scheme in the first hierarchical layer, a single <NUM> carrier may be used in the second hierarchical layer. The <NUM> carrier may occupy a portion of the radio frequency spectrum that at least partially overlaps the radio frequency spectrum used by one or more of the four <NUM> carriers. In some examples, scalable bandwidth for the second hierarchical layer type may be combined techniques to provide shorter RTTs such as described above, to provide further enhanced data rates.

Each of the different operating modes that may be employed by wireless communications system <NUM> may operate according to 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 in the communication links <NUM> for LTE downlink transmissions for each hierarchical layer, while single carrier frequency division multiple access (SC-FDMA) communications signals may be used in the communication links <NUM> for LTE uplink transmissions in each hierarchical layer. Additional details regarding implementation of hierarchical layers in a system such as the wireless communications system <NUM>, as well as other features and functions related to communications in such systems, are provided below with reference to the following figures.

<FIG> is a diagram illustrating an example of an access network <NUM> in an LTE network architecture. In this example, the access network <NUM> is divided into a number of cellular regions (cells) <NUM>. One or more lower power class eNBs <NUM> may have cellular regions <NUM> that overlap with one or more of the cells <NUM>. The lower power class eNB <NUM> may be a femto cell (e.g., home eNB (HeNB)), pico cell, micro cell, or remote radio head (RRH). The macro eNBs <NUM> are each assigned to a respective cell <NUM> and are configured to provide an access point to the Evolved Packet Core for all the UEs <NUM> (see <FIG>) in the cells <NUM>. In an aspect, eNBs <NUM> may constitute an access point <NUM> of <FIG> and may include a downlink scheduling component <NUM> configured to expedite communication of control information and user data with the number of UEs <NUM> using an Quick LTE data structure, for example but not limited to data structure <NUM> of <FIG>, which may include a TTI of one slot for some RE blocks. Similarly, one or more of UEs <NUM> may include a downlink management component <NUM> configured to receive, decode and operate using the data structure. There is no centralized controller in this example of an access network <NUM>, but a centralized controller may be used in alternative configurations. The eNBs <NUM> are responsible for all radio related functions including radio bearer control, admission control, mobility control, scheduling, security, and connectivity to the serving gateway <NUM>.

The modulation and multiple access scheme employed by the access network <NUM> may vary depending on the particular telecommunications standard being deployed. In LTE applications, OFDM is used on the DL and SC-FDMA is used on the UL to support both frequency division duplexing (FDD) and time division duplexing (TDD). As those skilled in the art will readily appreciate from the detailed description to follow, the various concepts presented herein are well suited for LTE applications. However, these concepts may be readily extended to other telecommunication standards employing other modulation and multiple access techniques. By way of example, these concepts may be extended to Evolution-Data Optimized (EV-DO) or Ultra Mobile Broadband (UMB). EV-DO and UMB are air interface standards promulgated by the 3rd Generation Partnership Project <NUM> (3GPP2) as part of the CDMA2000 family of standards and employs CDMA to provide broadband Internet access to mobile stations. These concepts may also be extended to Universal Terrestrial Radio Access (UTRA) employing Wideband-CDMA (W-CDMA) and other variants of CDMA, such as TD-SCDMA; Global System for Mobile Communications (GSM) employing TDMA; and Evolved UTRA (E-UTRA), IEEE <NUM> (Wi-Fi), IEEE <NUM> (WiMAX), IEEE <NUM>, and Flash-OFDM employing 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 the multiple access technology employed will depend on the specific application and the overall design constraints imposed on the system.

The eNBs <NUM> may have multiple antennas supporting MIMO technology. The use of MIMO technology enables the eNBs <NUM> to exploit the spatial domain to support spatial multiplexing, beamforming, and transmit diversity. Spatial multiplexing may be used to transmit different streams of data simultaneously on the same frequency. The data steams may be transmitted to a single UE <NUM> to increase the data rate or to multiple UEs <NUM> to increase the overall system capacity. This is achieved by spatially precoding each data stream (i.e., applying a scaling of an amplitude and a phase) and then transmitting each spatially precoded stream through multiple transmit antennas on the DL. The spatially precoded data streams arrive at the UE(s) <NUM> with different spatial signatures, which enables each of the UE(s) <NUM> to recover the one or more data streams destined for that UE <NUM>. On the UL, each UE <NUM> transmits a spatially precoded data stream, which enables the eNB <NUM> to identify the source of each spatially precoded data stream.

Spatial multiplexing is generally used when channel conditions are good. When channel conditions are less favorable, beamforming may be used to focus the transmission energy in one or more directions. This may be achieved by spatially precoding the data for transmission through multiple antennas. To achieve good coverage at the edges of the cell, a single stream beamforming transmission may be used in combination with transmit diversity.

In the detailed description that follows, various aspects of an access network will be described with reference to a MIMO system supporting OFDM on the DL. OFDM is a spread-spectrum technique that modulates data over a number of subcarriers within an OFDM symbol. The subcarriers are spaced apart at precise frequencies. The spacing provides "orthogonality" that enables a receiver to recover the data from the subcarriers. In the time domain, a guard interval (e.g., cyclic prefix) may be added to each OFDM symbol to combat inter-OFDM-symbol interference. The UL may use SC-FDMA in the form of a DFT-spread OFDM signal to compensate for high peak-to-average power ratio (PAPR).

<FIG> is a diagram <NUM> illustrating an example of a DL frame structure in LTE, which, in some examples, may be utilized in conjunction with the downlink frame structure provided by the present disclosure. A frame (<NUM>) may be divided into <NUM> equally sized sub-frames. Each sub-frame may include two consecutive time slots. A resource grid may be used to represent two time slots, each time slot including a resource element block. The resource grid is divided into multiple resource elements. In LTE, a resource element block may contain <NUM> consecutive subcarriers in the frequency domain and, for a normal cyclic prefix in each OFDM symbol, <NUM> consecutive OFDM symbols in the time domain, or <NUM> resource elements. For an extended cyclic prefix, a resource element block may contain <NUM> consecutive OFDM symbols in the time domain and has <NUM> resource elements. Some of the resource elements, as indicated as R <NUM>, <NUM>, include DL reference signals (DL-RS). The DL-RS include Cell-specific RS (CRS) (also sometimes called common RS) <NUM> and UE-specific RS (UE-RS) <NUM>. UE-RS <NUM> are transmitted only on the resource element blocks upon which the corresponding PDSCH is mapped. The number of bits carried by each resource element depends on the modulation scheme. Thus, the more resource element blocks that a UE receives and the higher the modulation scheme, the higher the data rate for the UE.

<FIG> is a diagram <NUM> illustrating an example of an UL frame structure in LTE. The available resource element blocks for the UL may be partitioned into a data section and a control section. The control section may be formed at the two edges of the system bandwidth and may have a configurable size. The resource element blocks in the control section may be assigned to UEs for transmission of control information. The data section may include all resource element blocks not included in the control section. The UL frame structure results in the data section including contiguous subcarriers, which may allow a single UE to be assigned all of the contiguous subcarriers in the data section.

A UE may be assigned resource element blocks 410a, 410b in the control section to transmit control information to an eNB. The UE may also be assigned resource element blocks 420a, 420b in the data section to transmit data to the eNB. The UE may transmit control information in a physical UL control channel (PUCCH) on the assigned resource element blocks in the control section. The UE may transmit only data or both data and control information in a physical UL shared channel (PUSCH) on the assigned resource element blocks in the data section. A UL transmission may span both slots of a subframe and may hop across frequency.

A set of resource element blocks may be used to perform initial system access and achieve UL synchronization in a physical random access channel (PRACH) <NUM>. The PRACH <NUM> carries a random sequence and cannot carry any UL data/signaling. Each random access preamble occupies a bandwidth corresponding to six consecutive resource element blocks. The starting frequency is specified by the network. That is, the transmission of the random access preamble is restricted to certain time and frequency resources. There is no frequency hopping for the PRACH. The PRACH attempt is carried in a single subframe (<NUM>) or in a sequence of few contiguous subframes and a UE can make only a single PRACH attempt per frame (<NUM>).

<FIG> is a diagram <NUM> illustrating an example of a radio protocol architecture for the user and control planes in LTE. The radio protocol architecture for the UE and the eNB is shown with three layers: Layer <NUM>, Layer <NUM>, and Layer <NUM>. Layer <NUM> (L1 layer) is the lowest layer and implements various physical layer signal processing functions. The L1 layer will be referred to herein as the physical layer <NUM>. Layer <NUM> (L2 layer) <NUM> is above the physical layer <NUM> and is responsible for the link between the UE and eNB over the physical layer <NUM>.

In the user plane, the L2 layer <NUM> includes a media access control (MAC) sublayer <NUM>, a radio link control (RLC) sublayer <NUM>, and a packet data convergence protocol (PDCP) <NUM> sublayer, which are terminated at the eNB on the network side. Although not shown, the UE may have several upper layers above the L2 layer <NUM> including a network layer (e.g., IP layer) that is terminated at the PDN gateway <NUM> on the network side, and an application layer that is terminated at the other end of the connection (e.g., far end UE, server, etc.).

The PDCP sublayer <NUM> provides multiplexing between different radio bearers and logical channels. The PDCP sublayer <NUM> also provides header compression for upper layer data packets to reduce radio transmission overhead, security by ciphering the data packets, and handover support for UEs between eNBs. The RLC sublayer <NUM> provides segmentation and reassembly of upper layer data packets, retransmission of lost data packets, and reordering of data packets to compensate for out-of-order reception due to hybrid automatic repeat request (HARQ). The MAC sublayer <NUM> provides multiplexing between logical and transport channels. The MAC sublayer <NUM> is also responsible for allocating the various radio resources (e.g., resource element blocks) in one cell among the UEs. The MAC sublayer <NUM> is also responsible for HARQ operations.

In the control plane, the radio protocol architecture for the UE and eNB is substantially the same for the physical layer <NUM> and the L2 layer <NUM> with the exception that there is no header compression function for the control plane. The control plane also includes a radio resource control (RRC) sublayer <NUM> in Layer <NUM> (L3 layer). The RRC sublayer <NUM> is responsible for obtaining radio resources (i.e., radio bearers) and for configuring the lower layers using RRC signaling between the eNB and the UE.

<FIG> is a block diagram of an eNB <NUM> in communication with a UE <NUM> in an access network. In the DL, upper layer packets from the core network are provided to a controller/processor <NUM>. The controller/processor <NUM> implements the functionality of the L2 layer. In the DL, the controller/processor <NUM> provides header compression, ciphering, packet segmentation and reordering, multiplexing between logical and transport channels, and radio resource allocations to the UE <NUM> based on various priority metrics. The controller/processor <NUM> is also responsible for HARQ operations, retransmission of lost packets, and signaling to the UE <NUM>.

The transmit (TX) processor <NUM> implements various signal processing functions for the L1 layer (i.e., physical layer). The signal processing functions includes coding and interleaving to facilitate forward error correction (FEC) at the UE <NUM> and mapping to signal constellations based on various modulation schemes (e.g., binary phase-shift keying (BPSK), quadrature phase-shift keying (QPSK), M-phase-shift keying (M-PSK), M-quadrature amplitude modulation (M-QAM)). The coded and modulated symbols are then split into parallel streams. Each stream is then mapped to 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 carrying a time domain OFDM symbol stream. Each spatial stream is then provided to a different antenna <NUM> via a separate transmitter 618TX. Each transmitter 618TX modulates an RF carrier with a respective spatial stream for transmission. In addition, eNB <NUM> may include a downlink scheduling component <NUM> configured to expedite communication of control information and user data with the number of UEs <NUM> using a data structure, for example but not limited to data structure <NUM> of <FIG>, which may include a TTI of one slot for some RE groups.

At the UE <NUM>, each receiver 654RX receives a signal through its respective antenna <NUM>. Each receiver 654RX recovers information modulated onto an RF carrier and provides the information to the receive (RX) processor <NUM>. The RX processor <NUM> implements various signal processing functions of the L1 layer. The RX processor <NUM> performs spatial processing on the information to recover any spatial streams destined for the UE <NUM>. The RX processor <NUM> then converts the OFDM symbol stream from the timedomain to the frequency domain using a Fast Fourier Transform (FFT). The symbols on each subcarrier, and the reference signal, is recovered and demodulated by determining the most likely signal constellation points transmitted by the eNB <NUM>. The soft decisions are then decoded and deinterleaved to recover the data and control signals that were originally transmitted by the eNB <NUM> on the physical channel. The data and control signals are then provided to the controller/processor <NUM>.

The controller/processor <NUM> implements the L2 layer. The controller/processor can be associated with a memory <NUM> that stores program codes and data. In the UL, the controller/processor <NUM> provides demultiplexing between transport and logical channels, packet reassembly, deciphering, header decompression, control signal processing to recover upper layer packets from the core network. The upper layer packets are then provided to a data sink <NUM>, which represents all the protocol layers above the L2 layer. Various control signals may also be provided to the data sink <NUM> for L3 processing. The controller/processor <NUM> is also responsible for error detection using an acknowledgement (ACK) and/or negative acknowledgement (NACK) protocol to support HARQ operations. In addition, UE <NUM> may include a downlink management component <NUM> configured to receive, decode and operate using the data structure of the present disclosure.

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

Channel estimates derived by a channel estimator <NUM> from a reference signal or feedback transmitted by the eNB <NUM> may be used by the TX processor <NUM> to select the appropriate coding and modulation schemes, and to facilitate spatial processing. The spatial streams generated by the TX processor <NUM> are provided to different antenna <NUM> via separate transmitters 654TX. Each transmitter 654TX modulates an RF carrier with a respective spatial stream for transmission.

The UL transmission is processed at the eNB <NUM> in a manner similar to that described in connection with the receiver function at the UE <NUM>. Each receiver 618RX receives a signal through its respective antenna <NUM>. Each receiver 618RX recovers information modulated onto an RF carrier and provides the information to a RX processor <NUM>. The RX processor <NUM> may implement the L1 layer.

The controller/processor <NUM> implements the L2 layer. In the UL, the controller/processor <NUM> provides demultiplexing between transport and logical channels, packet reassembly, deciphering, header decompression, control signal processing to recover upper layer packets from the UE <NUM>. Upper layer packets from the controller/processor <NUM> may be provided to the core network. In addition, controller/processor may be in communication with a.

<FIG> is a diagram illustrating a non-limiting example of a data structure <NUM> for managing expedited UE communications in a wireless communications system. In an aspect, data structure <NUM> includes frame scheduling for an example LTE subframe, which is divided in the time domain (horizontally) into two slots (slot <NUM><NUM> and slot <NUM><NUM>) and <NUM> symbols (symbols <NUM>-<NUM>). Furthermore, the temporal duration (horizontal axis) of some resource element blocks of data structure <NUM> may be one slot (<NUM> TTI), whereas other resource element blocks may have a temporal duration of both slots (<NUM> TTI). As such, by incorporating control and data channel resource element blocks having a TTI of one slot (<NUM>), data structure <NUM> allows for lower latency for downlink data transmissions relative to, for example, resource element blocks of legacy LTE downlink data structures, which have a mandated downlink data resource element block TTI of one subframe (<NUM>). Furthermore, data structure <NUM> provides for inter-operability with these existing legacy LTE data structures by allowing PDCCH, EPDCCH, and PDSCH resource element blocks to be scheduled along with the single-slot resource element blocks introduced by the present disclosure.

In an aspect of the present disclosure, data structure <NUM> may include one or more resource element blocks that each comprise one or more resource elements into which a downlink frequency bandwidth <NUM> is divided. For example, in example data structure <NUM>, slot <NUM><NUM> contains seven separate resource element blocks: resource element blocks <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, and <NUM>. Furthermore, each of the resource element blocks of data structure <NUM> may span a single slot or both slots. For example, again referencing the resource elements of slot <NUM><NUM>, resource element blocks <NUM>, <NUM>, <NUM>, and <NUM> span one slot (slot <NUM><NUM>), whereas resource element blocks <NUM>, <NUM>, and <NUM> span both slots of the subframe (slot <NUM><NUM> and slot <NUM><NUM>). In an aspect, the resource element blocks of example data structure <NUM> that span one slot may correspond to a Quick LTE channel of the present disclosure having a one-slot TTI, which may include a QEPDCCH (control channel) or a QPDSCH (data channel). Alternatively, the resource element blocks that span both subframes may correspond to a PDSCH (legacy LTE data channel), which may be granted to a particular UE by a PDCCH (e.g., in a legacy control region <NUM>), a QPDCCH (shown in data structure <NUM> as comprising one or more resource elements of symbol number <NUM> of slot <NUM><NUM>), or a EPDCCH (e.g., in resource element block <NUM>). In addition, a resource element block that spans both subframes may correspond to an EPDCCH (legacy LTE control channel), such as resource element block <NUM>.

In an additional aspect, each of the one or more resource element blocks may comprise a control channel region or a data channel region. For example, resource element blocks associated with a QPDCCH (e.g., located in symbol <NUM> of slot <NUM><NUM>), a QEPDCCH (e.g., resource element blocks <NUM> and <NUM>), an EPDCCH (e.g., resource element block <NUM>), or a PDCCH (e.g., located within legacy control region <NUM>) may each correspond to control channel regions. Alternatively, resource element blocks associated with a PDSCH (e.g., resource element block <NUM>) or a QPDSCH (e.g., resource element blocks <NUM>, <NUM>, and <NUM>) may correspond to data channel regions.

In addition, the one or more control channel regions of the data structure <NUM> may include one or more resource grants for one or more UEs served by one or shared downlink data channels. These downlink data channels may include a QPDSCH spanning a single slot of the subframe and/or a PDSCH spanning both slots of the subframe.

In an aspect, one or more of the control channel regions of the data structure <NUM> may correspond to a control channel that spans a single slot of the subframe (e.g., one of slot <NUM><NUM> or slot <NUM><NUM>). Such a single-slot control channel of the present disclosure may be referred to herein as QEPDCCH, which may have similar aspects to those of the legacy EPDCCH. However, unlike the EPDCCH, which spans both slots of a subframe (see resource element block <NUM>), the QEPDCCH spans a single slot of the subframe (see resource element blocks <NUM> and <NUM>). In an aspect, the QEPDCCH may utilize the same or similar enhanced control channel elements (ECCE) resource elements as legacy EPDCCH, although resource elements may be added relative to the legacy EPDCCH to compensate for the shorter QEPDCCH timeframe. In other words, the aggregation level of the QEPDCCH may be increased relative to the legacy EPDCCH (e.g., by a factor of two) to maintain similar coverage.

Furthermore, control channel regions of data structure <NUM> allocated to the QEPDCCH may include one or more uplink or downlink grants. For example, resource element block <NUM>, which is allocated to the QEPDCCH, includes both a downlink resource grant <NUM> for a UE <NUM> (for single-slot resource element block <NUM>) and an uplink resource grant <NUM> for a UE <NUM> (for a subsequent subframe). QEPDCCH resource element block <NUM>, on the other hand, does not contain an uplink resource grant, but contains two downlink resource grants: downlink resource grant <NUM> for UE <NUM> (for single-slot resource element block <NUM>) and downlink resource grant <NUM> for UE <NUM> (for single-slot resource element block <NUM>).

In an additional aspect of the present disclosure, a control channel region of data structure <NUM> may include a downlink channel grant for a data channel region resource element block that spans both slot <NUM><NUM> and slot <NUM><NUM> of the subframe. For example, resource element block <NUM> carries EPDCCH control data that may include a downlink grant for a legacy PDSCH channel data channel region that spans both slots, such as resource element block <NUM>. Alternatively, the data resource grant for resource element block <NUM> may be carried by a PDCCH of legacy control region <NUM>, which may contain resource elements for a legacy LTE control channel (e.g., PDCCH). In an aspect, although shown as spanning a single initial symbol <NUM> of the subframe, legacy control region <NUM> may alternatively span a plurality of initial symbols of the subframe.

Moreover, although the initial symbol (or symbols) of the subframe may contain the legacy control region <NUM>, the symbol may also contain resource elements for a QPDCCH channel of the present disclosure. Accordingly, the QPDCCH may utilize the control channel element (CCE) structure of the legacy PDCCH and may be fully multiplexed with other legacy control channels of legacy control region <NUM>. Furthermore, the QPDCCH may include one or more downlink resource grants for resource element blocks spanning either one or both slots of the subframe. In other words, the QPDCCH may include downlink resource grants for QPDSCH resource element blocks (spanning a single slot of the subframe, <NUM> TTI) or PDSCH resource element blocks (spanning both slots of the subframe, <NUM> TTI). For example, the QPDCCH may include a downlink resource grant for resource element block <NUM>, which includes a QPDSCH downlink transmission allocation for a UE <NUM>. Likewise, the QPDCCH may include a downlink resource grant for resource element block <NUM>, which includes a PDSCH downlink transmission allocation for a UE <NUM>. In an additional aspect, as the QPDCCH may include downlink grants for resource element blocks for the single-slot QPDSCH or for the full-subframe PDCCH, the QPDCCH may include a downlink control indicator (DCI) that specifies whether a downlink channel grant is for a single slot or for a full subframe. Furthermore, though not explicitly shown in data structure <NUM>, like the legacy LTE PDCCH, the QPDCCH may include uplink grants in addition to downlink grants.

Furthermore, the resource element blocks that comprise data channel regions may correspond to resource element allocations for downlink transmission of user data to one or more UEs. In an aspect, these data channel regions may include resource element blocks allocated to downlink channels that transmit the user data over a single-slot (e.g., QPDSCH resource element blocks <NUM>, <NUM>, <NUM>, and <NUM>) or downlink channels that transmit the user data over both slots of the subframe (e.g., PDSCH resource element blocks <NUM> and <NUM>.

Therefore, as illustrated in <FIG>, data structure <NUM> includes a Quick LTE downlink resource element allocation structure for some resource element blocks that may implement a slot-based allocation scheme, thereby shortening (e.g. halving) the TTI relative to full-subframe-based legacy LTE downlink resource element allocation schemes. By utilizing this Quick LTE downlink resource element allocation structure, over-the-air latency may be significantly reduced (e.g., by a factor of two). Accordingly, a round-trip time (RTT) of a HARQ process using the Quick LTE structure may be reduced to <NUM> from the <NUM> RTT of the legacy LTE RTT.

In an additional feature, data structure <NUM> may allocate resource elements in a downlink subframe for UEs that utilize one or both of (a) the Quick LTE channels of the present disclosure that span a single slot and may have a <NUM> TTI (e.g., QPDCCH, QEPDCCH, QPDSCH) and (b) legacy LTE channels that span the entire subframe and may therefore have a <NUM> TTI. In addition, because data structure <NUM> mirrors the general <NUM> subframe structure of legacy LTE, introducing the Quick LTE structure does not alter basic communication operations, such as, but not limited to, cell search procedures, system information block reading, random access channel (RACH) procedures (with media access channel (MAC) enhancements for contention-based RACH, paging, and idle mode procedures. Furthermore, UEs may easily indicate whether they support the Quick LTE communication during connection setup (e.g., via a dedicated information element or message), and in response, a network entity (e.g., an eNB) may provide the configuration parameters for the Quick LTE downlink and uplink channels.

Moreover, in some examples, cell-specific reference signal (CRS)-based demodulation may be utilized for the slot-based resource element allocation of the Quick LTE structure to minimize its specification and implementation impact, as CRS-based demodulation is widely used in legacy LTE systems. Alternatively, demodulation reference signal (DMRS)-based demodulation may be utilized. DMRS-based demodulation can allow for sufficient resources to be used for channel estimation for each slot of a subframe. For example, DMRS allows for increased density, as a UE-specific reference signal (UERS) pattern defined for Time-Division Duplex (TDD) Downlink Pilot Time Slot (DwPTS) can be reused for both slots of a subframe. In addition, DMRS-based demodulation allows for UE combining across consecutive assignments. As both CRS and DMRS-based demodulation are utilized by legacy LTE systems, utilizing these demodulation schemes for Quick LTE communication allows for further increased compatibility.

In addition, by reducing transmission from one subframe of legacy LTE to one slot of the Quick LTE structure of the present disclosure, the amount of resources for data transmission is effectively reduced by half. As such, to facilitate transmission of the same amount of data using the reduced resources available in a single slot, an increase in code rate (e.g., a doubled code rate) may be required. Alternatively or additionally, a number of resource blocks (RBs) (or resource elements) for a resource element block assignment may be increased (e.g., doubled). Therefore, where a resource element block assignment is compressed in time (e.g., changed from a subframe-based TTI to a single slot TTI), the number of resource RBs of the resource element block assignment may expanded. In addition, a two-resource-block minimum assignment may be mandated such that a similar code rate and transport block size can be maintained regardless of TTI size. However, where a one-RB minimum assignment is in place, a transport block size may be scaled by a factor of two. Alternatively, separate mapping rules may be provided for subframe-level (i.e., legacy LTE) assignments versus slot-level assignments (i.e., Quick LTE) with respect to transport block size, modulation and coding scheme (MCS), and resource block size. In addition, slot <NUM> and slot <NUM> may have a different mapping or scaling.

In addition, no channel state information (CSI) feedback change is needed relative to legacy LTE for CRS-based demodulation when Quick LTE slot-based resource element block assignment structures are utilized because the same feedback is provided regardless of transmission length or TTI. However, when generating the data structure <NUM>, an eNB may account for the total number of available resource elements to perform a mapping operation that includes selecting resource block assignments, MCS selection, and the like.

Moreover, in some examples, the same subframe-level channel state information reference signal (CSI-RS) and interference measurement resource (IMR) may be used regardless of the TTI of a resource element block (i.e., same for both Quick LTE and legacy LTE assignments). Alternatively, an eNB may generate a configuration whereby a CSI-RS and/or IMR are provided on a per-slot basis to provide greater granularity for slot-level assignments of Quick LTE.

Therefore, the data structure <NUM> of the present disclosure reduces over-the-air LTE latency by reducing the TTI interval of downlink channels while maintaining backward compatibility and coexistence with channels that utilize legacy LTE scheduling structures.

<FIG> is a block diagram containing a plurality of sub-components of a downlink scheduling component <NUM> (see <FIG>), which may be implemented by a network entity (e.g., an eNodeB) for scheduling expedited downlink transmissions (e.g., on a per-slot basis) of control information and/or user data to one or more UEs, for example, to reduce latency in an LTE system. Downlink scheduling component <NUM> may include a data structure generating component <NUM>, which may be configured to generate a data structure that manages downlink resource allocation for transmission of control information <NUM> and/or user data <NUM> to one or more UEs. In an aspect, the generated data structure may include any data structure described in the present disclosure, such as data structure <NUM> of <FIG>.

In an aspect, data structure generating component <NUM> may be configured to utilize a downlink scheduling algorithm <NUM>, which may be configured to perform scheduling of user data for transmission <NUM> in the data structure according to the methodologies and structures defined herein. For example, in some examples, downlink scheduling algorithm may maintain one or more look-up tables or maps that define transport block size, MCS, number of resource blocks, etc. for resource element block allocations having a single-slot TTI and for resource element block allocations having full-subframe TTIs. In addition, the data structure generating component <NUM> may include or otherwise obtain or identify one or more delivery constraints <NUM> associated with the user data for transmission <NUM> and/or one or more UEs to which the user data for transmission <NUM> is to be transmitted. In an aspect, such delivery constraints <NUM> may include downlink channel frequency bandwidth constraints (e.g., available resource blocks), QoS constraints, latency requirements, radio conditions, such as may be reported via a CSI message, an amount of data in a transmit queue for a UE, an amount of data for retransmission, e.g., due to operation of one or more HARQ processes, or any other constraint imposed by a particular UE, application, associated data, or network operation.

The data structure generating component <NUM> may utilize the downlink scheduling algorithm <NUM>, which may take at least the delivery constraints <NUM> and the user data for transmission <NUM> as input parameters, to generate the data structure to optimize scheduling of the user data for transmission <NUM> to the one or more UEs, for example, such that the data is transmitted with a TTI of one slot or a TTI of one subframe, depending on the particular resource element block to be assigned.

<FIG> illustrates an example method <NUM> of the present disclosure, which may be performed by a network entity (e.g., an eNodeB) that supports Quick LTE and/or legacy LTE or a component of the network entity, such as, but not limited to, downlink scheduling component <NUM> of <FIG> and <FIG>. For example, in an aspect, at block <NUM>, method <NUM> may include obtaining, at a network entity, user data for transmission to one or more UEs on a downlink channel. In some examples, the downlink channel may comprise one or both of a QPDSCH and a PDSCH. For example, in an aspect, an eNodeB may receive one or more data flows, for instance, from one or more network entities (e.g., another eNodeB, an MME, core network entity, or any other network entity) and may maintain or establish one or more radio bearers to one or more UEs to transmit user data from the data flows to the one or more UEs.

Furthermore, at block <NUM>, method <NUM> may include determining one or more delivery constraints associated with at least one of the data and the one or more UEs. In an aspect, such delivery constraints may include downlink channel frequency bandwidth constraints (e.g., available resource blocks), Quality of Service (QoS) constraints, latency requirements, radio conditions, such as may be reported via a channel state information (CSI) message, an amount of data in a transmit queue for a UE, an amount of data for retransmission, e.g., due to operation of one or more HARQ processes, or any other constraint imposed by a particular UE, application, associated data, or network operation.

In addition, at block <NUM>, method <NUM> may include generating, based on the user data for transmission and the one or more delivery constraints, a downlink subframe data structure for allocating downlink channel resources for transmission of the data. In an aspect, the data structure may include any data structure described in the present disclosure, such as data structure <NUM> of <FIG>. As such, the downlink subframe data structure at block <NUM> may include a downlink subframe comprising two slots and including one or more quick downlink channels having a single-slot transmission time interval. In an aspect, the quick downlink channels may correspond to the Quick LTE channels described in the present disclosure. In addition, the data structure may include one or more resource element blocks each comprising one or more resource elements into which a frequency bandwidth is divided within one or both of the two slots. Additionally, each of the one or more resource element blocks may include a control channel region or a data channel region. Moreover, the data structure may include one or more resource grants, located within one or more control channel regions, for one or more user equipment served by the one or more quick downlink channels. Optionally (as indicated by the dashed lines), at block <NUM>, method <NUM> may include transmitting the generated data structure, for example, to one or more UEs.

In addition, although not explicitly shown in <FIG>, method <NUM> may include one or more alternative or additional features. For example, method <NUM> may include increasing an aggregation level associated with the one or more quick downlink channels, for example, relative to channels having a full-subframe TTI. In addition, method <NUM> may include doubling a transport block size associated with the user data where the one or more resource element blocks of the quick downlink channel corresponding to the user data comprises a single resource block.

Furthermore, additional features of method <NUM> may be related to a HARQ process that may be associated with Quick LTE communications and may have a HARQ response time of about <NUM> or any other time less than that of a legacy LTE HARQ response. For example, method <NUM> may further comprise maintaining a HARQ process with an expedited retransmission time, wherein the expedited retransmission time is about <NUM>.

<FIG> is a conceptual data flow diagram <NUM> illustrating the data flow between different modules/means/components in an exemplary apparatus <NUM>. The apparatus <NUM> may be an access point (such as an eNodeB (eNB)), which may include access point <NUM> of <FIG>, macro eNB <NUM> or low power class eNB <NUM> of <FIG>, or eNB <NUM> of <FIG>. The apparatus includes a receiving module <NUM>, downlink scheduling component <NUM> (and its related data structure generating component <NUM> (see, e.g., <FIG>)), and a transmission module <NUM> that is configured to transmit at least a data structure (e.g., data structure <NUM> of <FIG>) and/or user data for transmission <NUM> to one or more UEs <NUM>.

The receiving module <NUM>, downlink scheduling component <NUM> (and the subcomponents thereof in <FIG>), or the transmission module <NUM> may perform one or more aspects of the aforementioned method <NUM> of <FIG>. For instance, receiving module <NUM> may be configured to receive user data <NUM> from one or more other network entities <NUM> in one or more data flows. The receiving module <NUM> may forward the user data <NUM> to the downlink scheduling component <NUM>, and as such, the downlink scheduling component <NUM> may obtain the forwarded user data <NUM>. The downlink scheduling component <NUM> may determine one or more delivery constraints associated with at least one of the user data <NUM> and the one or more UEs <NUM> and may generate a downlink subframe data structure for allocating downlink channel resources for transmission of the user data <NUM>. The downlink scheduling component <NUM> may send the downlink subframe data structure and the user data (together, <NUM>) to the transmission module <NUM>. The transmission module <NUM> may be configured to transmit at least the downlink subframe data structure and the user data (together, <NUM>) to the one or more UEs <NUM>.

In addition, the apparatus <NUM> may include additional modules that perform each of the steps of method <NUM> of <FIG>. As such, each step of method <NUM> may be additionally or alternatively performed by an additional module and the apparatus <NUM> may include one or more of those additional modules. The modules may be one or more hardware components specifically configured to carry out the stated processes/algorithm, implemented by a processor configured to perform the stated processes/algorithm, stored within a computer-readable medium for implementation by a processor, or some combination thereof.

<FIG> is a diagram <NUM> illustrating an example of a hardware implementation for an apparatus <NUM>' employing a processing system <NUM>. Like apparatus <NUM> of <FIG>, apparatus <NUM>' and/or processing system <NUM> may be an access point (such as an eNodeB (eNB)), which may include access point <NUM> of <FIG>, macro eNB <NUM> or low power class eNB <NUM> of <FIG>, or eNB <NUM> of <FIG>. The processing system <NUM> may be implemented with a bus architecture, represented generally by the bus <NUM>. The bus <NUM> may include any number of interconnecting buses and bridges depending on the specific application of the processing system <NUM> and the overall design constraints. The bus <NUM> links together various circuits including one or more processors and/or hardware modules, represented by the processor <NUM>, the downlink scheduling component <NUM> and its related data structure generating component <NUM> (see, e.g., <FIG>), and the computer-readable medium <NUM>. The bus <NUM> may also link various other circuits such as timing sources, peripherals, voltage regulators, and power management circuits, which are well known in the art, and therefore, will not be described any further.

The processing system <NUM> may be coupled to a transceiver <NUM>, which, in some examples, may include receiving module <NUM> and transmission module <NUM> of <FIG>. The transceiver <NUM> is coupled to one or more antennas <NUM>. The transceiver <NUM> provides a means for communicating with various other apparatus over a transmission medium. In addition, the transceiver <NUM> may be configured to transmit a data structure and/or user data for transmission to one or more UEs. The processing system <NUM> includes a processor <NUM> coupled to a computer-readable medium <NUM>. The processor <NUM> is responsible for general processing, including the execution of software stored on the computer-readable medium <NUM>. The software, when executed by the processor <NUM>, causes the processing system <NUM> to perform the various functions described supra for any particular apparatus. The computer-readable medium <NUM> may also be used for storing data that is manipulated by the processor <NUM> when executing software. The processing system further includes at least one of downlink scheduling component <NUM> and its related data structure generating component <NUM> (see, e.g., <FIG>). The modules/components may be software modules running in the processor <NUM>, resident/stored in the computer-readable medium <NUM>, one or more hardware modules coupled to the processor <NUM>, or some combination thereof. The processing system <NUM> may be a component of the eNB <NUM> and may include the memory <NUM> and/or at least one of the TX processor <NUM>, the RX processor <NUM>, and the controller/processor <NUM>.

In one configuration, the apparatus <NUM>' for wireless communication includes means for obtaining user data for transmission <NUM> to one or more UEs on a downlink channel; means for determining one or more delivery constraints <NUM> associated with at least one of the data and the one or more UEs; and means for generating, based on the user data for transmission <NUM> and the one or more delivery constraints <NUM>, a downlink subframe data structure for allocating downlink channel resources for transmission of the user data for transmission <NUM>. The aforementioned means may be one or more of the aforementioned modules of the apparatus <NUM> and/or the processing system <NUM> of the apparatus <NUM>' configured to perform the functions recited by the aforementioned means.

Furthermore, like method <NUM>, which may be performed by an example eNB of the present disclosure, one or more UEs (e.g., UE <NUM> of <FIG> or UE <NUM> of <FIG>) may perform methods related to the LTE data structures presented herein. For instance, <FIG> illustrates an example method <NUM> of the present disclosure, which may be performed by a UE (e.g., UE <NUM> of <FIG>, <FIG> and <FIG>) that supports Quick LTE and/or legacy LTE. In an aspect, aspects of method <NUM> may be performed by downlink management component <NUM> (see <FIG>, <FIG>, <FIG>) and/or any other component (e.g., controller/processor <NUM> of <FIG>) of a UE.

In an aspect, method <NUM> includes receiving, at a UE, control information located at one or more resource element positions in a control channel region of a downlink subframe or slot at block <NUM>. This control channel region may include at least a portion of a downlink data structure (see data structure <NUM> of <FIG>) defined by one or more resource elements or resource element blocks. In an aspect, block <NUM> may be performed by receiving module <NUM> of <FIG> or transceiver <NUM> of <FIG>.

In addition, method <NUM> includes, at block <NUM>, performing a check on the control channel region received at each of the one or more resource element positions to determine if the control information is for the UE. In an aspect, this check may include a cyclic redundancy check (CRC). Furthermore, in some examples, block <NUM> may be performed by control channel region checking component <NUM> of <FIG>.

In addition, at block <NUM>, method <NUM> includes determining, where the check passes, a position of a data channel region and a TTI length of the data channel region based on the control information. This data channel region may include at least a portion of a downlink data structure (see data structure <NUM> of <FIG>) defined by one or more resource elements or resource element blocks. In some examples, block <NUM> may be performed by data channel region determining component <NUM>.

Moreover, at block <NUM>, method <NUM> includes receiving, at the determined position, downlink data in the data channel region. In some examples, block <NUM> may be performed by receiving module <NUM> of <FIG> or transceiver <NUM> of <FIG>.

In addition, it is understood that the specific order or hierarchy of steps in the methods disclosed in <FIG> and <FIG> is an illustration of exemplary approaches. Based upon design preferences, it is understood that the specific order or hierarchy of steps in the processes may be rearranged. Further, some steps may be combined or omitted. The accompanying method claims present elements of the various steps in a sample order, and are not meant to be limited to the specific order or hierarchy presented.

<FIG> is a conceptual data flow diagram <NUM> illustrating the data flow between different modules/means/components in an exemplary apparatus <NUM>, which may be a UE (e.g., UE <NUM> of <FIG>, <FIG>, and <FIG>). In an aspect, the apparatus <NUM> includes a receiving module <NUM> that is configured to receive data <NUM>, which may include a data structure <NUM> of <FIG> and associated control data received via a control channel and/or downlink data via a data channel. Such data <NUM> may be transmitted to apparatus <NUM>, for example, by a network entity <NUM>, which may include, but is not limited to, access point <NUM> of <FIG>, macro eNB <NUM> or low power class eNB <NUM> of <FIG>, or eNB <NUM> of <FIG>, any of which may include downlink scheduling component <NUM> and its related data structure generating component <NUM> (see, e.g., <FIG>). For instance, receiving module <NUM> may be configured to receive control information located at one or more resource element positions in a control channel region of a downlink subframe or slot as defined by a received data structure (data structure <NUM> of <FIG>). In addition, receiving module <NUM> may be configured to receive user data in a data channel region of the received data structure, where the user data is received at a determined position in the received data structure corresponding to a particular frequency band. The receiving module <NUM> may send the received data <NUM> to the downlink management component <NUM>.

In addition, apparatus <NUM> may contain a downlink management component <NUM> (see <FIG> and <FIG>) and a plurality of sub-components thereof, which may be implemented by apparatus <NUM> to decode and process data (e.g., received data <NUM>) and operate using the data structure <NUM> of <FIG>, for example, to reduce latency in an LTE system. Downlink management component <NUM> may include a control region checking component <NUM>, which may be configured to perform a check on the control channel region received at each of one or more resource element positions in the received data structure to determine if the control information is for the apparatus <NUM>. In an aspect, this check may include a CRC.

In addition, downlink management component <NUM> may include a data channel region determining component <NUM>, which may be configured to determine, where the check performed by control region checking component <NUM> passes, a position of a data channel region <NUM> and a TTI length of the data channel region <NUM> based on the control information included in the received data structure. This data channel region may include at least a portion of a downlink data structure (see data structure <NUM> of <FIG>) defined by one or more resource elements or resource element blocks. In an aspect, the downlink management component <NUM> may be configured to send the position of the data channel region <NUM> and the TTI length of data channel region <NUM> to the receiving module <NUM>, which may utilize this information to receive data <NUM> transmitted by access point <NUM>.

The apparatus may include additional modules that perform each of the steps of the algorithm in the aforementioned flow chart of <FIG>. As such, each step in the aforementioned flow charts of <FIG> may be performed by a module and the apparatus may include one or more of those modules. The modules may be one or more hardware components specifically configured to carry out the stated processes/algorithm, implemented by a processor configured to perform the stated processes/algorithm, stored within a computer-readable medium for implementation by a processor, or some combination thereof.

<FIG> is a diagram <NUM> illustrating an example of a hardware implementation for an apparatus <NUM>' employing a processing system <NUM>. Like apparatus <NUM> of <FIG>, apparatus <NUM>' and/or processing system <NUM> may be a UE (e.g., UE <NUM> of <FIG>, <FIG>, and <FIG>). The processing system <NUM> may be implemented with a bus architecture, represented generally by the bus <NUM>. The bus <NUM> may include any number of interconnecting buses and bridges depending on the specific application of the processing system <NUM> and the overall design constraints. The bus <NUM> links together various circuits including one or more processors and/or hardware modules, represented by the processor <NUM>, the downlink management component <NUM> (see, e.g., <FIG>), and the computer-readable medium <NUM>. The bus <NUM> may also link various other circuits such as timing sources, peripherals, voltage regulators, and power management circuits, which are well known in the art, and therefore, will not be described any further.

The processing system <NUM> may be coupled to a transceiver <NUM>, which, in some examples, may include receiving module <NUM> of <FIG>. The transceiver <NUM> is coupled to one or more antennas <NUM>. The transceiver <NUM> provides a means for communicating with various other apparatus (e.g., access point <NUM> of <FIG> and <FIG>) over a transmission medium. In addition, the transceiver <NUM> may be configured to receive a data structure and/or user data. The processing system <NUM> includes a processor <NUM> coupled to a computer-readable medium <NUM>. The processor <NUM> is responsible for general processing, including the execution of software stored on the computer-readable medium <NUM>. The software, when executed by the processor <NUM>, causes the processing system <NUM> to perform the various functions described supra for any particular apparatus. The computer-readable medium <NUM> may also be used for storing data that is manipulated by the processor <NUM> when executing software. The processing system further includes downlink management component <NUM> and its related subcomponents (see, e.g., <FIG>). The modules/components may be software modules running in the processor <NUM>, resident/stored in the computer-readable medium <NUM>, one or more hardware modules coupled to the processor <NUM>, or some combination thereof. The processing system <NUM> may be a component of the UE <NUM> and may include the memory <NUM> and/or at least one of the TX processor <NUM>, the RX processor <NUM>, and the controller/processor <NUM> of <FIG>.

In one configuration, the apparatus <NUM>' for wireless communication includes means for receiving, at a UE, control information located at one or more resource element positions in a control channel region of a downlink; means for performing a check on the control channel region received at each of the one or more resource element positions to determine if the control information is for the UE; means for determining, where the check passes, a position of a data channel region and a TTI length of the data channel region based on the control information; and means for receiving, at the determined position, downlink data in the data channel region.

Claim 1:
A method for managing user equipment, UE, communications in a wireless communications system, comprising:
receiving (<NUM>), at the UE, control information located at one or more resource element positions in a control channel region of a downlink subframe or a slot of the downlink subframe, wherein the downlink subframe comprises:
two slots and includes one or more quick downlink channels having a single-slot transmission time interval, TTI; and
one or more resource element blocks each comprising one or more resource elements into which a frequency bandwidth is divided within one or both of the two slots, wherein each of the one or more resource element blocks comprises the control channel region or a data channel region corresponding to the one or more quick downlink channels; and wherein at least the control channel region is multiplexed, within at least one symbol, with a legacy control channel region;
performing (<NUM>) a check on the control channel region received at each of the one or more resource element positions to determine whether corresponding control information is for the UE;
determining (<NUM>), where the check indicates the corresponding control information is for the UE, a position of the data channel region and a transmission time interval, TTI, length of the data channel region based on the corresponding control information; and
receiving (<NUM>), at the determined position, downlink data in the data channel region.