SPECTRUM

PRIORITY CLAIM

[0001] This application claims the benefit of priority to United States

Provisional Patent Application Serial No. 62/109,509, filed, January 29, 2015, and entitled "A NOVEL DATA TRANSMISSION SCHEME IN WIRELESS COMMUNICATION SYSTEMS," which is incorporated herein by reference in its entirety.

TECHNICAL FIELD

[0002] Embodiments pertain to radio access networks. Some embodiments relate to the use of unlicensed spectrum in cellular networks, including Third Generation Partnership Project Long Term Evolution (3 GPP LTE) networks and LTE advanced (LTE-A) networks as well as 4 ^th generation (4G) networks and 5 ^th generation (5G) networks. BACKGROUND

[0003] Long Term Evolution (LTE) networks operate in a number of specific frequency bands and deliver a wide variety of information to an ever- increasing number and type of user equipment (UE). Typically, the use of different communication techniques is limited to licensed bands regulated by the federal government. However, the growth of data use is outstripping the availability of bandwidth in the LTE spectrum and consequently has led, in 3GPP Release 13, to a desire to expand LTE use by UEs and evolved NodeBs (eNBs) beyond the licensed spectrum. This may result in additional complexity when LTE devices use License Assisted Access (LAA), i.e., the unlicensed spectrum (LTE-Unlicensed (LTE-U) operation). Unlike the licensed spectrum, in which only LTE systems are able to legally operate and thus timing and scheduling of communications may be tightly controlled, LTE systems coexist with other systems in the unlicensed spectrum. LAA devices may make use of the 5GHz Unlicensed National Information Infrastructure (U-NII) bands, in which Wireless Local Area Network (WLAN) systems using IEEE 802.1 la/n/ac technologies have enjoyed widespread use by both individuals and operators for a variety of purposes to increase capacity while still ensuring end user quality of service.

[0004] Because the timing and scheduling is subject to fluctuations when using the unlicensed spectrum, due to the random nature of interference, an LAA transmitter may acquire the medium at any time in a subframe/symbol and consequently may not be aligned with the LTE subframe boundary. The resulting time gap is unused and is thus inefficient in terms of resource use. It may thus be desirable to enable use of the unaligned resources in the unlicensed spectrum.

BRIEF DESCRIPTION OF THE FIGURES

[0005] In the figures, which are not necessarily drawn to scale, like numerals may describe similar components in different views. Like numerals having different letter suffixes may represent different instances of similar components. The figures illustrate generally, by way of example, but not by way of limitation, various embodiments discussed in the present document.

[0006] FIG. 1 shows an example of a portion of an end-to-end network architecture of an LTE network with various components of the network in accordance with some embodiments.

[0007] FIG. 2 illustrates example components of a UE in accordance with some embodiments.

[0008] FIG. 3 illustrates a LAA data burst transmission structure in accordance with some embodiments.

[0009] FIGS. 4A-4D illustrate LAA cross-carrier scheduling in accordance with some embodiments.

[0010] FIGS. 5A-5D illustrate other LAA cross-carrier scheduling in accordance with some embodiments. [0011] FIGS. 6A and 6B illustrate timing between Downlink Control

Information (DCI) format and physical downlink shared channel (PDSCH) transmission in accordance with some embodiments.

[0012] FIGS. 7A and 7B illustrate further LAA cross-carrier scheduling in accordance with some embodiments.

[0013] FIGS. 8A and 8B illustrate self-scheduling in a LAA serving cell in accordance with some embodiments.

[0014] FIGS. 9A-9D illustrate scheduling operations in fractional subframes in accordance with some embodiments.

[0015] FIGS. 10A-10D illustrate further scheduling operations in fractional subframes in accordance with some embodiments.

[0016] FIGS. 1 lA-1 IB illustrate conditional scheduling operations in fractional subframes in accordance with some embodiments.

[0017] FIGS. 12A-12C illustrate transport block size determination in fractional subframes in accordance with some embodiments.

[0018] FIG. 13 illustrates a flowchart of a method of PDSCH scheduling in accordance with some embodiments.

DETAILED DESCRIPTION OF THE INVENTION

[0019] The following description and the drawings sufficiently illustrate specific embodiments to enable those skilled in the art to practice them. Other embodiments may incorporate structural, logical, electrical, process, and other changes. Portions and features of some embodiments may be included in, or substituted for, those of other embodiments. Embodiments set forth in the claims encompass all available equivalents of those claims.

[0020] FIG. 1 shows an example of a portion of an end-to-end network architecture of a Long Term Evolution (LTE) network with various components of the network in accordance with some embodiments. As used herein, an LTE network refers to both LTE and LTE Advanced (LTE-A) networks as well as other versions of LTE networks to be developed. The network 100 may comprise a radio access network (RAN) (e.g., as depicted, the E-UTRAN or evolved universal terrestrial radio access network) 101 and core network 120 (e.g., shown as an evolved packet core (EPC)) coupled together through an SI interface 115. For convenience and brevity, only a portion of the core network 120, as well as the RAN 101, is shown in the example.

[0021] The core network 120 may include a mobility management entity (MME) 122, serving gateway (serving GW) 124, and packet data network gateway (PDN GW) 126. The RAN 101 may include evolved node Bs (eNBs) 104 (which may operate as base stations) for communicating with user equipment (UE) 102. The eNBs 104 may include macro eNBs and low power (LP) eNBs. The eNBs 104 and UEs 102 may be LAA devices, which use carrier aggregation (CA) and the unaligned resources, as described herein.

[0022] The MME 122 may be similar in function to the control plane of legacy Serving GPRS Support Nodes (SGSN). The MME 122 may manage mobility aspects in access such as gateway selection and tracking area list management. The serving GW 124 may terminate the interface toward the RAN 101, and route data packets between the RAN 101 and the core network 120. In addition, the serving GW 124 may be a local mobility anchor point for inter-eNB handovers and also may provide an anchor for inter-3GPP mobility. Other responsibilities may include lawful intercept, charging, and some policy enforcement. The serving GW 124 and the MME 122 may be implemented in one physical node or separate physical nodes.

[0023] The PDN GW 126 may terminate an SGi interface toward the packet data network (PDN). The PDN GW 126 may route data packets between the EPC 120 and the external PDN, and may perform policy enforcement and charging data collection. The PDN GW 126 may also provide an anchor point for mobility devices with non-LTE access. The external PDN can be any kind of IP network, as well as an IP Multimedia Subsystem (IMS) domain. The PDN GW 126 and the serving GW 124 may be implemented in a single physical node or separate physical nodes.

[0024] The eNBs 104 (macro and micro) may terminate the air interface protocol and may be the first point of contact for a UE 102. In some embodiments, an eNB 104 may fulfill various logical functions for the RAN 101 including, but not limited to, RNC (radio network controller functions) such as radio bearer management, uplink and downlink dynamic radio resource management and data packet scheduling, and mobility management. In accordance with embodiments, UEs 102 may be configured to communicate orthogonal frequency division multiplexed (OFDM) communication signals with an eNB 104 over a multicarrier communication channel in accordance with an OFDMA communication technique. The OFDM signals may comprise a plurality of orthogonal subcarriers.

[0025] The S 1 interface 1 15 may be the interface that separates the RAN

101 and the EPC 120. It may be split into two parts: the S l-U, which may carry traffic data between the eNBs 104 and the serving GW 124, and the Sl-MME, which may be a signaling interface between the eNBs 104 and the MME 122. The X2 interface may be the interface between eNBs 104. The X2 interface may comprise two parts, the X2-C and X2-U. The X2-C may be the control plane interface between the eNBs 104, while the X2-U may be the user plane interface between the eNBs 104.

[0026] With cellular networks, LP cells may be typically used to extend coverage to indoor areas where outdoor signals do not reach well, or to add network capacity in areas with dense usage. In particular, it may be desirable to enhance the coverage of a wireless communication system using cells of different sizes, macrocells, microcells, picocells, and femtocells, to boost system performance. The cells of different sizes may operate on the same frequency band, or may operate on different frequency bands with each cell operating in a different frequency band or only cells of different sizes operating on different frequency bands. As used herein, the term low power (LP) eNB refers to any suitable relatively low power eNB for implementing a smaller cell (smaller than a macro cell) such as a femtocell, a picocell, or a microcell. Femtocell eNBs may be typically provided by a mobile network operator to its residential or enterprise customers. A femtocell may be typically the size of a residential gateway or smaller and generally connect to a broadband line. The femtocell may connect to the mobile operator's mobile network and provide extra coverage in a range of typically 30 to 50 meters. Thus, a LP eNB might be a femtocell eNB since it is coupled through the PDN GW 126. Similarly, a picocell may be a wireless communication system typically covering a small area, such as in- building (offices, shopping malls, train stations, etc.), or more recently in- aircraft. A picocell eNB may generally connect through the X2 link to another eNB such as a macro eNB through its base station controller (BSC)

functionality. Thus, LP eNB may be implemented with a picocell eNB since it may be coupled to a macro eNB via an X2 interface. Picocell eNBs or other LP eNBs may incorporate some or all functionality of a macro eNB. In some cases, this may be referred to as an access point base station or enterprise femtocell.

[0027] Other wireless communication devices may be present in the same geographical region as the RAN 101. As shown in FIG. 1, WLAN devices including one or more access points (APs) 103 and one or more stations (STAs) 105 in communication with the AP 103. The WLAN devices may communicate using one or more IEEE 802.1 1 protocols, such as IEEE 802.1 la/b/n/ac protocols. As the power of the WLAN devices 103, 105 may be fairly limited, compared with the eNBs 104, the WLAN devices 103, 105 may be

geographically localized.

[0028] Communication over an LTE network may be split up into 10ms frames, each of which may contain ten 1ms subframes. Each subframe of the frame, in turn, may contain two slots of 0.5ms. Each subframe may be used for uplink (UL) communications from the UE 102 to the eNB 104 or downlink (DL) communications from the eNB 104 to the UE 102. In one embodiment, the eNB 104 may allocate a greater number of DL communications than UL

communications in a particular frame. The eNB 104 may schedule

transmissions over a variety of frequency bands (fi and {2). The allocation of resources in subframes used in one frequency band and may differ from those in another frequency band. Each slot of the subframe may contain 6-7 symbols, depending on the system used. In one embodiment, the subframe may contain 12 subcarriers. A downlink resource grid may be used for downlink transmissions from an eNB to a UE, while an uplink resource grid may be used for uplink transmissions from a UE to an eNB or from a UE to another UE. The resource grid may be a time-frequency grid, which is the physical resource in the downlink in each slot. The smallest time-frequency unit in a resource grid may be denoted as a resource element (RE). Each column and each row of the resource grid may correspond to one OFDM symbol and one OFDM subcarrier, respectively. The resource grid may contain resource blocks (RBs) that describe the mapping of physical channels to resource elements and physical RBs (PRBs). A PRB may be the smallest unit of resources that can be allocated to a UE. A resource block may be 180 kHz wide in frequency and 1 slot long in time. In frequency, resource blocks may be either 12 x 15 kHz subcarriers or 24 x 7.5 kHz subcarriers wide. For most channels and signals, 12 subcarriers may be used per resource block, dependent on the system bandwidth. In Frequency Division Duplexed (FDD) mode, both the uplink and downlink frames may be 10ms and frequency (full-duplex) or time (half-duplex) separated. In Time Division Duplexed (TDD), the uplink and downlink subframes may be transmitted on the same frequency and are multiplexed in the time domain. The duration of the resource grid 400 in the time domain corresponds to one subframe or two resource blocks. Each resource grid may comprise 12

(subcarriers) * 14 (symbols) =168 resource elements.

[0029] There may be several different physical downlink channels that are conveyed using such resource blocks, including the physical downlink control channel (PDCCH) and the physical downlink shared channel (PDSCH). Each subframe may be partitioned into the PDCCH and the PDSCH. The PDCCH may normally occupy the first two symbols of each subframe and carries, among other things, information about the transport format and resource allocations related to the PDSCH channel, as well as H-ARQ information related to the uplink shared channel. The PDSCH may carry user data and higher layer signaling to a UE and occupy the remainder of the subframe. Typically, downlink scheduling (assigning control and shared channel resource blocks to UEs within a cell) may be performed at the eNB 104 based on channel quality information provided from the UE 102s to the eNB 104, and then the downlink resource assignment information may be sent to each UE on the PDCCH used for (assigned to) the UE 102. The PDCCH may contain downlink control information (DCI) in one of a number of formats that tell the UE 102 how to find and decode data, transmitted on PDSCH in the same subframe, from the resource grid. The DCI format may provide details such as number of resource blocks, resource allocation type, modulation scheme, transport block, redundancy version, coding rate etc. Each DCI format may have a cyclic redundancy check (CRC) and be scrambled with a Radio Network Temporary Identifier (RNTI) that identifies the target UE for which the PDSCH is intended. Use of the UE 102-specific RNTI may limit decoding of the DCI format (and hence the corresponding PDSCH) to only the intended UE.

[0030] In addition to the PDCCH, an enhanced PDCCH (EPDCCH) may be used by the eNB 104 and UE 102. The PDSCH may contain data in some of the RBs and the EPDCCH may contain the downlink control signals in others of the RBs of the bandwidth supported by the UE 102. Different UEs may have different EPDCCH configurations. The sets of RBs corresponding to EPDCCH may be configured, for example, by higher layer signaling such as Radio Resource Control (RRC) signaling for EPDCCH monitoring.

[0031] Similarly, a Physical Uplink Control Channel (PUCCH) may be used by the UE 102 to send Uplink Control Information (UCI) to the eNB 104. The PUCCH may be mapped to an UL control channel resource defined by an orthogonal cover code and two resource blocks (RBs), consecutive in time, with hopping potentially at the boundary between adjacent slots. The PUCCH may take several different formats, with the UCI containing information dependent on the format. Specifically, the PUCCH may contain a scheduling request (SR), acknowledgement responses/retransmission requests (ACK/NACK) or a Channel Quality Indication (CQI)/Channel State Information (CSI). The CQI/CSI may indicate to the eNB 104 an estimate of the current downlink channel conditions as seen by the UE 102 to aid channel-dependent scheduling and, if one MIMO transmission mode is configured to the UE 102, may include MIMO-related feedback (e.g. Precoder matrix indication, PMI).

[0032] Embodiments described herein may be implemented into a system using any suitably configured hardware and/or software. FIG. 2 illustrates example components of a UE in accordance with some embodiments. In some embodiments, the UE 200 may include application circuitry 202, baseband circuitry 204, Radio Frequency (RF) circuitry 206, front-end module (FEM) circuitry 208 and one or more antennas 210, coupled together at least as shown.

[0033] The application circuitry 202 may include one or more application processors. For example, the application circuitry 202 may include circuitry such as, but not limited to, one or more single-core or multi-core processors. The processor(s) may include any combination of general-purpose processors and dedicated processors (e.g., graphics processors,

application processors, etc.). The processors may be coupled with and/or may include memory/storage and may be configured to execute instructions stored in the memory/storage to enable various applications and/or operating systems to run on the system.

[0034] The baseband circuitry 204 may include circuitry such as, but not limited to, one or more single-core or multi-core processors. The baseband circuitry 204 may include one or more baseband processors and/or control logic to process baseband signals received from a receive signal path of the RF circuitry 206 and to generate baseband signals for a transmit signal path of the RF circuitry 206. Baseband processing circuity 204 may interface with the application circuitry 202 for generation and processing of the baseband signals and for controlling operations of the RF circuitry 206. For example, in some embodiments, the baseband circuitry 204 may include a second generation (2G) baseband processor 204a, third generation (3G) baseband processor 204b, fourth generation (4G) baseband processor 204c, and/or other baseband processor(s) 204d for other existing generations, generations in development or to be developed in the future (e.g., fifth generation (5G), 6G, etc.). The baseband circuitry 204 (e.g., one or more of baseband processors 204a-d) may handle various radio control functions that enable communication with one or more radio networks via the RF circuitry 206. The radio control functions may include, but are not limited to, signal modulation/demodulation,

encoding/decoding, radio frequency shifting, etc. In some embodiments, modulation/demodulation circuitry of the baseband circuitry 204 may include Fast-Fourier Transform (FFT), precoding, and/or constellation

mapping/demapping functionality. In some embodiments, encoding/decoding circuitry of the baseband circuitry 204 may include convolution, tail-biting convolution, turbo, Viterbi, and/or Low Density Parity Check (LDPC) encoder/decoder functionality. Embodiments of modulation/demodulation and encoder/decoder functionality are not limited to these examples and may include other suitable functionality in other embodiments.

[0035] In some embodiments, the baseband circuitry 204 may include elements of a protocol stack such as, for example, elements of an evolved universal terrestrial radio access network (EUTRAN) protocol including, for example, physical (PHY), media access control (MAC), radio link control (RLC), packet data convergence protocol (PDCP), and/or radio resource control (RRC) elements. A central processing unit (CPU) 204e of the baseband circuitry 204 may be configured to run elements of the protocol stack for signaling of the PHY, MAC, RLC, PDCP and/or RRC layers. In some embodiments, the baseband circuitry may include one or more audio digital signal processor(s) (DSP) 204f. The audio DSP(s) 204f may be include elements for

compression/decompression and echo cancellation and may include other suitable processing elements in other embodiments. Components of the baseband circuitry may be suitably combined in a single chip, a single chipset, or disposed on a same circuit board in some embodiments. In some embodiments, some or all of the constituent components of the baseband circuitry 204 and the application circuitry 202 may be implemented together such as, for example, on a system on a chip (SOC).

[0036] In some embodiments, the baseband circuitry 204 may provide for communication compatible with one or more radio technologies. For example, in some embodiments, the baseband circuitry 204 may support communication with an evolved universal terrestrial radio access network (EUTRAN) and/or other wireless metropolitan area networks (WMAN), a wireless local area network (WLAN), a wireless personal area network (WPAN). Embodiments in which the baseband circuitry 204 is configured to support radio communications of more than one wireless protocol may be referred to as multi-mode baseband circuitry. [0037] RF circuitry 206 may enable communication with wireless networks using modulated electromagnetic radiation through a non-solid medium. In various embodiments, the RF circuitry 206 may include switches, filters, amplifiers, etc. to facilitate the communication with the wireless network. RF circuitry 206 may include a receive signal path which may include circuitry to down-convert RF signals received from the FEM circuitry 208 and provide baseband signals to the baseband circuitry 204. RF circuitry 206 may also include a transmit signal path which may include circuitry to up-convert baseband signals provided by the baseband circuitry 204 and provide RF output signals to the FEM circuitry 208 for transmission.

[0038] In some embodiments, the RF circuitry 206 may include a receive signal path and a transmit signal path. The receive signal path of the RF circuitry 206 may include mixer circuitry 206a, amplifier circuitry 206b and filter circuitry 206c. The transmit signal path of the RF circuitry 206 may include filter circuitry 206c and mixer circuitry 206a. RF circuitry 206 may also include synthesizer circuitry 206d for synthesizing a frequency for use by the mixer circuitry 206a of the receive signal path and the transmit signal path. In some embodiments, the mixer circuitry 206a of the receive signal path may be configured to down-convert RF signals received from the FEM circuitry 208 based on the synthesized frequency provided by synthesizer circuitry 206d. The amplifier circuitry 206b may be configured to amplify the down-converted signals and the filter circuitry 206c may be a low-pass filter (LPF) or band-pass filter (BPF) configured to remove unwanted signals from the down-converted signals to generate output baseband signals. Output baseband signals may be provided to the baseband circuitry 204 for further processing. In some embodiments, the output baseband signals may be zero-frequency baseband signals, although this is not a requirement. In some embodiments, mixer circuitry 206a of the receive signal path may comprise passive mixers, although the scope of the embodiments is not limited in this respect.

[0039] In some embodiments, the mixer circuitry 206a of the transmit signal path may be configured to up-convert input baseband signals based on the synthesized frequency provided by the synthesizer circuitry 206d to generate RF output signals for the FEM circuitry 208. The baseband signals may be provided by the baseband circuitry 204 and may be filtered by filter circuitry 206c. The filter circuitry 206c may include a low-pass filter (LPF), although the scope of the embodiments is not limited in this respect.

[0040] In some embodiments, the mixer circuitry 206a of the receive signal path and the mixer circuitry 206a of the transmit signal path may include two or more mixers and may be arranged for quadrature downconversion and/or upconversion respectively. In some embodiments, the mixer circuitry 206a of the receive signal path and the mixer circuitry 206a of the transmit signal path may include two or more mixers and may be arranged for image rejection (e.g.,

Hartley image rejection). In some embodiments, the mixer circuitry 206a of the receive signal path and the mixer circuitry 206a may be arranged for direct downconversion and/or direct upconversion, respectively. In some embodiments, the mixer circuitry 206a of the receive signal path and the mixer circuitry 206a of the transmit signal path may be configured for super-heterodyne operation.

[0041] In some embodiments, the output baseband signals and the input baseband signals may be analog baseband signals, although the scope of the embodiments is not limited in this respect. In some alternate embodiments, the output baseband signals and the input baseband signals may be digital baseband signals. In these alternate embodiments, the RF circuitry 206 may include analog-to-digital converter (ADC) and digital-to-analog converter (DAC) circuitry and the baseband circuitry 204 may include a digital baseband interface to communicate with the RF circuitry 206.

[0042] In some dual-mode embodiments, a separate radio IC circuitry may be provided for processing signals for each spectrum, although the scope of the embodiments is not limited in this respect.

[0043] In some embodiments, the synthesizer circuitry 206d may be a fractional-N synthesizer or a fractional N/N+l synthesizer, although the scope of the embodiments is not limited in this respect as other types of frequency synthesizers may be suitable. For example, synthesizer circuitry 206d may be a delta-sigma synthesizer, a frequency multiplier, or a synthesizer comprising a phase-locked loop with a frequency divider. [0044] The synthesizer circuitry 206d may be configured to synthesize an output frequency for use by the mixer circuitry 206a of the RF circuitry 206 based on a frequency input and a divider control input. In some embodiments, the synthesizer circuitry 206d may be a fractional N/N+l synthesizer.

[0045] In some embodiments, frequency input may be provided by a voltage controlled oscillator (VCO), although that is not a requirement. Divider control input may be provided by either the baseband circuitry 204 or the applications processor 202 depending on the desired output frequency. In some embodiments, a divider control input (e.g., N) may be determined from a look- up table based on a channel indicated by the applications processor 202.

[0046] Synthesizer circuitry 206d of the RF circuitry 206 may include a divider, a delay-locked loop (DLL), a multiplexer and a phase accumulator. In some embodiments, the divider may be a dual modulus divider (DMD) and the phase accumulator may be a digital phase accumulator (DPA). In some embodiments, the DMD may be configured to divide the input signal by either N or N+1 (e.g., based on a carry out) to provide a fractional division ratio. In some example embodiments, the DLL may include a set of cascaded, tunable, delay elements, a phase detector, a charge pump and a D-type flip-flop. In these embodiments, the delay elements may be configured to break a VCO period up into Nd equal packets of phase, where Nd is the number of delay elements in the delay line. In this way, the DLL provides negative feedback to help ensure that the total delay through the delay line is one VCO cycle.

[0047] In some embodiments, synthesizer circuitry 206d may be configured to generate a carrier frequency as the output frequency, while in other embodiments, the output frequency may be a multiple of the carrier frequency (e.g., twice the carrier frequency, four times the carrier frequency) and used in conjunction with quadrature generator and divider circuitry to generate multiple signals at the carrier frequency with multiple different phases with respect to each other. In some embodiments, the output frequency may be a LO frequency (fix)). In some embodiments, the RF circuitry 206 may include an IQ/polar converter. [0048] FEM circuitry 208 may include a receive signal path which may include circuitry configured to operate on RF signals received from one or more antennas 210, amplify the received signals and provide the amplified versions of the received signals to the RF circuitry 206 for further processing. FEM circuitry 208 may also include a transmit signal path which may include circuitry configured to amplify signals for transmission provided by the RF circuitry 206 for transmission by one or more of the one or more antennas 210.

[0049] In some embodiments, the FEM circuitry 208 may include a

TX/RX switch to switch between transmit mode and receive mode operation. The FEM circuitry may include a receive signal path and a transmit signal path. The receive signal path of the FEM circuitry may include a low-noise amplifier (LNA) to amplify received RF signals and provide the amplified received RF signals as an output (e.g., to the RF circuitry 206). The transmit signal path of the FEM circuitry 208 may include a power amplifier (PA) to amplify input RF signals (e.g., provided by RF circuitry 206), and one or more filters to generate RF signals for subsequent transmission (e.g., by one or more of the one or more antennas 210.

[0050] In some embodiments, the UE 200 may include additional elements such as, for example, memory/storage, display, camera, sensor, and/or input/output (I/O) interface. As shown, the UE 200 may thus contain a transceiver and processing circuitry configured to carry out at least some of the functions described herein. The other components, such as the eNB shown in FIG. 1 may contain at least some of the components shown in FIG. 2.

[0051] As described above, as the demand for communicating data (e.g., voice and video) continues to increase, LTE networks may experience increasingly heavy communication traffic, leading to adverse network effects such as reduced data rates, increased delay and increased interference. To alleviate network traffic on the LTE licensed spectrum and increase network capacity communication capability, a communication spectrum not licensed exclusively for use by the cellular network devices (UEs and eNBs) may be employed. With the increase in network usage, communication peaks may occur locally and the LTE network serving the location may experience peak demand at certain times of the day or week, or when special events such as sports events or concerts occur. As above, the location may also be serviced by a WLAN network, such as an IEEE 802.1 1 network including a WiFi network. However, because the WLAN network operates in an unlicensed spectrum, availability and characteristics of the channels operating in the band may be an issue. UEs and eNBs 104 that operate in the unlicensed spectrum in addition to the licensed LTE band may be referred to as LAA UEs 102 and LAA eNBs 104, which are generally referred to herein merely as UEs 102 and eNBs 104.

[0052] Use of the unlicensed spectrum alone may not increase the capacity sufficiently. Carrier aggregation (CA) may additionally be used to increase bandwidth, and thus bitrate, by using multiple carriers to form a larger overall transmission bandwidth. The channels (frequency ranges) of the carriers can either be adjacent or separated by a substantial distance, e.g., being in different frequency bands. Thus, for example, CA may be used to aggregate carriers in the licensed band and carriers in the unlicensed spectrum to increase capacity. To implement CA, certain control information may be communicated between the UE 102 and eNB 104. For example, to ensure fair channel access to all users of the unlicensed spectrum, a Listen-Before-Talk (LBT)-based adaptive channel access mechanism may be used. An eNB 104 using LBT may perform a clear channel assessment (CCA) to assess the channel and obtain channel access. The CCA duration may not be an integral fraction of the OFDM symbol duration (about 70μ8) as the minimum requirement for CCA duration is 20μ8 and the cyclic prefix lengths may change across symbols. As above, due to the random nature of interference experienced in the unlicensed spectrum, an LAA transmitter (e.g., eNB 104 for downlink (DL)) may potentially acquire the medium at any time in the middle of a subframe/symbol and not be aligned with the symbol boundary. The unused time gap may be formed when the unlicensed channel availability is not aligned with the LTE subframe boundary.

[0053] In some embodiments, the DL LAA transmissions may assume subframe boundary alignment according to the Release 12 CA timing relationships across serving cells aggregated by the CA. In addition, one or more signals can be transmitted by the eNB 104 between the time the eNB 104 is permitted to transmit and the start of data transmission to reserve the channel. Since the time duration from reserving the shared channel until next subframe boundary for actual data transmission is able to be up to 13 OFDM symbols, it may be desirable to effectively exploit the fractional subframe for data transmission to improve the LAA system throughput performance, since it is counted as part of the maximum transmission duration. A fractional subframe is the portion of a subframe existing between the time when the eNB 104 is able to obtain channel access and the next LTE subframe boundary aligns between the LTE system (assisting serving cell) and unlicensed system (LAA serving cell). The fractional subframe may have a duration of between about 0 OFDM symbols and close to 14 OFDM symbols (assuming a normal CRC so 7 symbols exist/slot).

[0054] Various techniques are disclosed herein for scheduling a PDSCH transmission in a fractional subframe in a LAA system. In some embodiments, the modulation and coding scheme (MCS) and resource allocation for a PDSCH in a fractional subframe may be preconfigured by higher layer signaling, or dynamically scheduled using negative- direction scheduling using a legacy (pre- Release 13/Releases 8-12) DCl format or new DCl format. The DCl format can be carried by a PDCCH or enhanced PDCCH (ePDCCH). More specially, in some embodiments, the scheduled transport block (TB) can be mapped in a fractional subframe that has fewer OFDM symbols compared to a regular DL subframe, or the TB may be mapped to two consecutive subframes including a fractional frame and a following regular DL subframe. Correspondingly, how to handle the transport block size (TBS) for the different mapping schemes to maximize spectrum efficiency is described below.

[0055] FIG. 3 illustrates a LAA data burst transmission structure in accordance with some embodiments. FIG. 3 shows an assisting serving cell 302 communicating with the UE on the licensed band and an LAA serving cell 304 communicating with the UE on the unlicensed spectrum. As shown in FIG. 3, a LAA burst transmission 310 can be generally split into three parts: a first fractional DL subframe 312 (part 1), a number of consecutive normal DL subframes 314 (part 2), and a second fractional DL subframe 316 (part 3). The second fractional DL subframe may occur because of regional regulations indicating a limited maximum transmission duration. For cross-carrier scheduling, the UE may be configured with a carrier indicator field (CIF) for a given LAA serving cell. The CIF may be located on the PDCCH and indicate on which carrier the scheduled resource is located. In particular, the CIF may indicate that a licensed assisting serving cell transmits the DL allocations for the given unlicensed serving cell. After the first fractional DL subframe 312 and consecutive normal DL subframes 314, the subframe boundary 320 between the licensed band DL transmissions and the unlicensed spectrum may be aligned. In the following embodiments, it is assumed that a LAA transmission (except preamble signal) starts from OFDM symbol X, where X>0, in a subframe n with K ms duration.

[0056] FIGS. 4A-4D illustrate LAA cross-carrier scheduling in accordance with some embodiments. The UE may be configured with a carrier indicator field, which may be used as described in reference to FIG. 3 in various PDCCH monitoring and PDSCH reception schemes for scheduling PDSCH transmissions. As in FIG. 3, FIGS. 4A-4D illustrate an assisting serving cell 410, 430, 450, 470 communicating with the UE on the licensed band and an LAA serving cell 420, 440, 460, 480 communicating with the UE on the unlicensed spectrum. The assisting serving cell 410, 430, 450, 470 may transmit using subframes 412, 432, 452, 472 each having a PDCCH 414, 434, 454, 474 and a PDSCH 416, 436, 456, 476. The first subframe (subframe n) on which data may be able to be transmitted by the LAA serving cell 420, 440, 460, 480 may be a fractional subframe 424, 444, 464, 484 having a preamble 422, 442, 462, 482, and a full subframe 426, 446, 466, 486 (subframe n+1) consecutive to the fractional subframe 424, 444, 464, 484. Full subframes may also be referred to herein as normal or regular subframes.

[0057] Scheduling of the PDSCH transmission may be for both the fractional subframe 424, 444, 464, 484 and full subframe 426, 446, 466, 486. More specifically, it may be desirable to enable use of the PDSCH in the fractional subframe 424, 444, 464, 484 for transmission immediately following the preamble 422, 442, 462, 482 to maximize the spectrum efficiency on the unlicensed spectrum 420, 440, 460, 480.

[0058] As shown in FIG. 4A, separate legacy DCIs 418a, 418b may be independently transmitted in PDCCH 414 in the full subframe 426 to schedule PDSCH transmission in transport blocks of the fractional subframe 424 and the full subframe 426 on the LAA serving cell 420. In other words, the DCI formats 418a, 418b transmitted in the PDCCH of subframe n+1 412 schedule the PDSCH transmission for both the partial and full subframe 424 and 426. The UE may store in memory the information in the fractional subframe and decode the PDSCH after obtaining the PDCCH in the following full subframe.

[0059] The legacy DCIs 418a, 418b may be modified to provide the scheduling information by adding a 1 -bit indication field into the legacy DCI formats that are supported on a LAA serving cell. The 1 -bit indication field may have a first value, say 0, indicating a DCI format for the PDSCH in the fractional subframe 424 and another value 1 indicating a DCI format for the PDSCH in the full subframe 426. A new R TI (e.g., a LAA-RNTI) may be additionally configured by higher layer signaling, such as RRC control signaling. The first DCI may have a CRC scrambled by the new RNTI, and be intended for the fractional subframe 424. Similarly, the second DCI may have a CRC scrambled by the C-RNTI, and be intended for the full subframe 426.

[0060] To reduce the DL control overhead, a new compact DCI format may be used for scheduling PDSCH transmission in the fractional subframe 424. In some embodiments, the candidate MCS used in new DCI format may be limited to a subset of MCS schemes supported in LTE to reduce the number of bits used by the MCS field. The MCS candidates may be fixed by the specification or may be preconfigured by higher-layer signaling. In some embodiments, the new DCI format may have a smaller size as compared to current DCI formats supported in LTE to minimize control overhead. The transport blocks scheduled in the partial and full subframe 424 and 426 may be independent of each other, each having an independent MCS and resource allocation (including subcarriers). This is to say that the transport blocks in the partial and full subframe 424 and 426 may have the same MCS and resource allocation, different MCS and resource allocation, or one of the MCS and resource allocation may be the same and the other may be different.

[0061] Instead of separate legacy DCIs being used to schedule PDSCH transmission in transport blocks of the fractional subframe and the full subframe, as shown in FIG. 4B, a jointly-coded DCI format 438 may be used. The jointly- coded DCI format 438 may be provided in the PDCCH 434 of the full subframe 446 of the assisted serving cell 430 to schedule multiple PDSCH transmissions - PDSCH transmission in transport blocks of both the fractional subframe 444 and the full subframe 446 on the LAA serving cell 440. The DCI format 438 may merely be a new DCI format that is formed by concatenating two legacy DCI formats. In this case, as above, the new DCI format may enable the transport blocks scheduled in the partial and full subframe 444 and 446 to be independent of each other, each having an independent MCS and resource allocation.

[0062] Rather than the transport blocks scheduled in the partial and full subframe being independent of each other, in some embodiments, as shown in FIGS. 4C and 4D, scheduling of the PDSCH transmission in the fractional subframe and the full subframe may be linked. In some embodiments, as shown in FIG. 4C, a single legacy DCI 458 may be provided in the PDCCH 454 of the full subframe 466 of the assisted serving cell 450. The single legacy DCI 458 may be used to schedule the PDSCH transmission in transport blocks of both the fractional subframe 464 and the full subframe 466 on the LAA serving cell 460. In this case, as the same legacy DCI 458 is used, the transport blocks scheduled in the partial and full subframe 464 and 466 are the same, each having the same MCS and resource allocation.

[0063] As shown in FIG. 4D, similar to FIG. 4C, a single legacy DCI

478 may be provided in the PDCCH 474 of the full subframe 486 of the assisted serving cell 470. The single legacy DCI 478 may be used to schedule the PDSCH transmission in transport blocks of both the fractional subframe 484 and the full subframe 486 on the LAA serving cell 480. The scheduled PDSCH transmission in this case, unlike the arrangement shown in FIG. 4C, may be mapped to resource elements (REs) in a frequency- first order across both the fractional subframe 484 and the full subframe 486 on the LAA serving cell 480. Thus, in FIG. 4C two sets of transportation blocks with possibly different CRC may be scheduled using the same DCI format, whereas in FIG. 4D a single transportation block containing a CRC may be scheduled using a single DCI format, leading to a lower control overhead.

[0064] FIGS. 5A-5D illustrate other LAA cross-carrier scheduling in accordance with some embodiments. However, while FIGS. 4A-4D illustrate embodiments in which the DCI format is transmitted in the PDCCH, FIGS. 5A- 5D are directed to embodiments in which the DCI format is transmitted in the EPDCCH. Specifically, FIGS. 5A-5D illustrate an assisting serving cell 510, 530, 550, 570 communicating with the UE on the licensed band and an LAA serving cell 520, 540, 560, 580 communicating with the UE on the unlicensed spectrum. The assisting serving cell 510, 530, 550, 570 may transmit using subframes 512, 532, 552, 572 each having a PDCCH 514, 534, 554, 574 and a PDSCH 516, 536, 556, 576 containing an EPDCCH 528, 548, 568, 588. The first subframe (subframe n) on which data may be able to be transmitted by the LAA serving cell 520, 540, 560, 580 may be a fractional subframe 524, 544, 564, 584 having a preamble 522, 542, 562, 582, and a full subframe 526, 546, 566, 586 (subframe n+1) consecutive to the fractional subframe 524, 544, 564, 584.

[0065] As shown in FIG. 5A, separate legacy DCIs 518a, 518b may be independently transmitted in the EPDCCH 528 in the full subframe 526 to schedule PDSCH transmission in transport blocks of the fractional subframe 524 and the full subframe 526 on the LAA serving cell 520. In other words, the DCI formats 518a, 518b transmitted in the EPDCCH 528 of subframe n+1 512 schedule the PDSCH transmission for both the partial and full subframe 524 and 526.

[0066] The legacy DCIs 518a, 518b may be modified to provide the scheduling information by adding a 1 -bit indication field into the legacy DCI formats that are supported on a LAA serving cell. The 1 -bit indication field may have a first value, say 0, indicating a DCI format for the PDSCH in the fractional subframe 524 and another value 1 indicating a DCI format for the PDSCH in the full subframe 526. A new RNTI (e.g., a LAA-RNTI) may be additionally configured by higher layer signaling, such as RRC control signaling. The first DCl may have a CRC scrambled by the new R TI, and be intended for the fractional subframe 524. Similarly, the second DCl may have a CRC scrambled by the C-RNTI, and be intended for the full subframe 526.

[0067] As above, a compact DCl format may be used for scheduling

PDSCH transmission in the fractional subframe 524. In some embodiments, the candidate MCS used in new DCl format may be limited to a subset of MCS schemes supported in LTE to reduce the number of bits used by the MCS field. The MCS candidates may be fixed by the specification or may be preconfigured by higher-layer signaling. In some embodiments, the new DCl format may have a smaller size as compared to current DCl formats supported in LTE to minimize control overhead. The transport blocks scheduled in the partial and full subframe 524 and 526 may be independent of each other, each having an independent MCS and resource allocation (including subcarriers). This is to say that the transport blocks in the partial and full subframe 524 and 526 may have the same MCS and resource allocation, different MCS and resource allocation, or one of the MCS and resource allocation may be the same and the other may be different.

[0068] Instead of separate legacy DCIs being used to schedule PDSCH transmission in transport blocks of the fractional subframe and the full subframe, as shown in FIG. 5B, a jointly-coded DCl format 538 may be used. The jointly- coded DCl format 538 may be provided in the EPDCCH 548 of the full subframe 546 of the assisted serving cell 530 to schedule multiple PDSCH transmissions - PDSCH transmission in transport blocks of both the fractional subframe 544 and the full subframe 546 on the LAA serving cell 540. The DCl format 538 may merely be a new DCl format that is formed by concatenating two legacy DCl formats. In this case, as above, the new DCl format may enable the transport blocks scheduled in the partial and full subframe 544 and 546 to be independent of each other, each having an independent MCS and resource allocation.

[0069] Rather than the transport blocks scheduled in the partial and full subframe being independent of each other, in some embodiments, as shown in FIGS. 5C and 5D, scheduling of the PDSCH transmission in the fractional subframe and the full subframe may be linked. In some embodiments, as shown in FIG. 5C, a single legacy DCI 558 may be provided in the EPDCCH 568 of the full subframe 566 of the assisted serving cell 550. The single legacy DCI 558 may be used to schedule the PDSCH transmission in transport blocks of both the fractional subframe 564 and the full subframe 566 on the LAA serving cell 560. In this case, as the same legacy DCI 558 is used, the transport blocks scheduled in the partial and full subframe 564 and 566 are the same, each having the same MCS and resource allocation.

[0070] As shown in FIG. 5D, similar to FIG. 5C, a single legacy DCI

578 may be provided in the EPDCCH 588 of the full subframe 586 of the assisted serving cell 570. The single legacy DCI 578 may be used to schedule the PDSCH transmission in transport blocks of both the fractional subframe 584 and the full subframe 586 on the LAA serving cell 580. The scheduled PDSCH transmission in this case, unlike the arrangement shown in FIG. 5C, may be mapped to REs in a frequency- first order across both the fractional subframe 584 and the full subframe 586 on the LAA serving cell 580.

[0071] As shown in FIGS. 5A-5D, the DCI formats 518a, 518b, 538,

558, 478 may occur in a predetermined location within the various EPDCCH 528, 548, 568, 588. Although not shown, other than the initial fractional subframe and the first regular (non-partial) subframe the same UE behavior of (E)PDCCH monitoring may be applied to the remaining non-discontinuous reception (DRX) subframes (subframe n+2 to subframe n+K). This is to say that, in subframe n+2 for example, the UE may monitor a UE-specific search space at each of the carrier aggregation levels (e.g., 1 , 2, 4, 8) on the corresponding assisting serving cell in subframe n+2 for a PDSCH transmission in the subframe n+2 in the LAA serving cell. Legacy DCIs may be used in the remaining subframes to transport downlink scheduling information for the PDSCH transmissions in the LAA serving cell.

[0072] FIGS. 6A and 6B illustrate timing between DCI format and

PDSCH transmission in accordance with some embodiments. In particular, FIGS. 6A and 6B illustrate a timing relationship between transmission of a DCI format 618, 638 on the assisted serving cell 610 and the scheduled PDSCH transmission 624, 644 in a LAA transmission 622, 642 on a LAA serving cell 620, 640 in subframe n+2. In some embodiments, as shown in FIG. 6A, the legacy DCI format 618 may be carried by the PDCCH 614 in subframe n+2 612. In some embodiments, as shown in FIG. 6B, the legacy DCI format 638 may be carried by the EPDCCH 636 rather than the PDCCH 634 in subframe n+2 632.

[0073] FIGS. 7A and 7B illustrate further LAA cross-carrier scheduling in accordance with some embodiments. In FIGS. 7A and 7B, the UE may be configured for EPDCCH monitoring on the assisting serving cell 750, 770, and be configured with a carrier indicator field. In this case, PDSCH transmissions 756, 776 may be implemented in subframe n and n+1 752, 772 depending on the total number of available OFDM symbols in the fractional subframe 764, 784.

[0074] As discussed, OFDM symbols in the fractional subframe 764, 784 may range from 0 to 13. Let X denote the first OFDM symbol within a LAA burst transmission following the preamble 762, 782. When X < 8, the eNB may use a legacy DCI 758, 778 transmitted in EPDCCH 768, 788 (rather than the PDCCH 754, 774) in subframe n 752, 772 to schedule one PDSCH 756, 776 mapping to PRBs in sub frames n and n+1 either individually or together. In particular, in FIG. 7A, one PDSCH 756 mapping defined by the legacy DCI format 758 (Legacy DCI 1) may be used to schedule PRBs 766 (indicated as TBI) only in the fractional subframe 764 of the LAA serving cell 760. As shown in FIG. 7A, another legacy DCI format 758 (Legacy DCI 2) in the EPDCCH 768 of subframe n+1 752 may be used to schedule PRBs (indicated as TB2) in subframe n+1 of the LAA serving cell 760. Alternatively, as shown in FIG. 7B, one PDSCH 776 mapping defined by the legacy DCI format 778 (Legacy DCI 1) may be used to schedule PRBs in 786 both the fractional subframe 784 and full subframe 788 of the LAA serving cell 780. These embodiments may permit the decoding latency in decoding the PDSCH transmitted in the fractional subframe 764, 784 may be minimized.

[0075] FIGS. 8 A and 8B illustrate self-scheduling in a LAA serving cell in accordance with some embodiments. In particular, FIGS. 8A and 8B show respectively the DCI format 816, 826 in the PDCCH 814 or the EPDCCH 824 of a subframe 812, 822 the LAA serving cell may be used for PDSCH 818, 828 scheduling. As shown in FIG. 8B, the scheduling in the EPDCCH 824 of the subframe 822 may occur prior to the PDSCH 828, and the EPDCCH 824 and the PDSCH 828 may use different resource blocks (e.g., subcarriers). The size of the (E)PDCCH region 814, 824 in terms of OFDM symbols may be configured on a semi-static basis by higher layer signaling. Similar to the above and as shown in FIGS. 8A and 8B, the existing (E)PDCCH transmission scheme used in the licensed spectrum may be reused in sub frames from n+1 to n+K-2 on the LAA serving cell for the PDSCH scheduling.

[0076] FIGS. 9A-9D illustrate scheduling operations in fractional subframes in accordance with some embodiments. PDCCH transmission and PDSCH scheduling operations may be implemented in the fractional subframes n and n+K (shown in FIG. 3 as fractional subframes 312 and 316) in several ways. In the embodiments shown in FIGS. 9A-9D, the fractional subframe 912, 922, 932, 942 may not contain a PDCCH region. This may permit minimization of the control overhead in the LAA system. Instead, the PDSCH in the fractional subframe 912, 922, 932, 942 may be scheduled by the PDCCH 914, 924, 934, 944 in the full subframe 910, 920, 930, 940.

[0077] FIGS. 10A-10D illustrate scheduling operations in fractional subframes in accordance with some embodiments. Like FIGS. 9A-9D, FIGS. 10-lOD illustrate scheduling of a fractional subframe 1012, 1022, 1032, 1042 using a full subframe 1010, 1020, 1030, 1040; in this case however, the fractional subframe 1012, 1022, 1032, 1042 occurs after, rather than before, the full subframe 1010, 1020, 1030, 1040. Specifically, FIGS. 1 OA- 10D illustrate that the PDSCH 1018, 1028, 1038, 1048 in fractional subframe n+K 1012, 1022, 1032, 1042 may be scheduled by the PDCCH 1014, 1024, 1034, 1044 in full subframe n+K-1 1010, 1020, 1030, 1040, the last full subframe. While FIGS. 10A-10D illustrate examples in which the DCI formats 1016a, 1016b, 1026, 1036, 1046 are in the PDCCH 1014, 1024, 1034, 1044, in some embodiments the DCI formats 1016a, 1016b, 1026, 1036, 1046 may be instead transmitted in an EPDCCH. [0078] In a manner similar to the cross-carrier scheduling mechanisms shown in FIGS. 4A-4D and 5A-5D, the PDSCH 918, 928, 938, 948 in the fractional subframe 912, 922, 932, 942 may be scheduled via one or two DCI formats 916a, 916b, 926, 936, 946. Although FIGS. 9A-9D illustrate examples in which the DCI formats 916a, 916b, 926, 936, 946 are in the PDCCH 914, 924, 934, 944, in some embodiments the DCI formats 916a, 916b, 926, 936, 946 may be instead transmitted in an EPDCCH. Specifically, in FIG. 9A, separate legacy DCI formats 916a, 916b may be independently transmitted in the PDCCH 914 in the subframe 910 to schedule PDSCH transmission 918 in the fractional and full subframe 912, 910. Similar mechanisms used to differentiate between these DCI formats 916a, 916b in cross-carrier scheduling case may be used in the mechanism shown in FIG. 9A. The separate legacy DCI formats 916a, 916b may be provided using different resource elements (e.g., subcarrier and/or symbol) of the PDCCH 914. Similarly, as shown in FIG. 10A, separate legacy DCIs 1016a, 1016b independently transmitted in the PDCCH 1014 in the last full subframe n+K-1 1010 may be used to schedule the PDSCH transmission 1018a in the last full subframe n+K- 1 1010 and the PDSCH transmission 1018b in the fractional subframe n+K 1012.

[0079] In FIG. 9B, a jointly-coded DCI format 926 may be transmitted in the PDCCH 924 in the full subframe 920 to schedule the PDSCH transmission 928 in both the fractional subframe 922 and full subframe 920. As above, in some embodiments, a new DCI format may be formed by directly concatenating two legacy DCI formats. Thus, the resource block associated with each PDSCH 928 transmission may be independent of each other. In addition, as shown in FIG. 10B, a jointly-coded DCI format 1026 may be transmitted in the PDCCH 1024 in full subframe n+K-1 1020 to schedule the PDSCH transmission 1028a, 1028b in both the full subframe n+K- 1 1020 and the fractional subframe n+K 1022.

[0080] In FIG. 9C, a single legacy DCI format 936 may be transmitted in the PDCCH 934 in the full subframe 930 to schedule the PDSCH transmission 938 in both the fractional subframe 932 and full subframe 930. As the same DCI format 926 is used to schedule multiple PDSCH transmissions 938, the same resource block in each subframe 920, 922 may be associated with each PDSCH 928 transmission. In addition, as shown in FIG. IOC, a legacy DCI format 1036 can be transmitted in the PDCCH 1034 in the full subframe n+K-1 1030 to schedule the PDSCH transmissions 1038a, 1038b in both the full subframe n+K- 1 1030 and the fractional subframe n+K 1032.

[0081] In FIG. 9D, a single legacy DCI format 946 may be transmitted in the PDCCH 944 in the full subframe 940 to schedule the PDSCH transmission 948 in the full subframe 940. In some embodiments, a single legacy DCI format may be transmitted in the PDCCH in subframe n+K- 1 to schedule a single PDSCH transmission. The scheduled PDSCH transmission 948 may be mapped to REs in a frequency- first order across both the fractional subframe 942 and the full subframe 940 if the PDCCH 944 is transmitted in the full subframe 940. The scheduled PDSCH 1048 may also be mapped to REs in a frequency- first order across both the full subframe n+K- 1 1040 and the fractional subframe n+K 1042 if the PDCCH 1044 is transmitted in the full subframe n+K- 1 1040.

[0082] FIGS. 1 lA-1 IB illustrate conditional scheduling operations in fractional sub frames in accordance with some embodiments. In FIGS. 1 lA-1 IB, the (E)PDCCH 1 1 14, 1 124 may be conditionally present in a fractional subframe 1 1 10, 1 120 depending on the available number of OFDM symbols 1 108, 1 128 in the fractional subframe 1 1 10, 1 120. To minimize the PDSCH decoding latency, it may be desirable to transmit the (E)PDCCH 1 1 14, 1 124 in fractional subframes 1 1 10, 1 120 after the preamble 1 1 12, 1122 such that UE can start decoding the associated PDSCH transmission 1 1 18, 1128 as soon as possible. Additionally, it may be desirable to consider control overhead to improve LAA system efficiency. In FIGS. 1 lA-1 IB show embodiments in which the PDCCH 1 1 14, 1 124 is present in a fractional subframe 1 1 10, 1 120 only if the available OFDM symbols 1 108, 1 128 for LAA data transmission within this subframe 1 1 10, 1 120 is at least a configurable threshold (otherwise, the PDCCH 1 1 14, 1 124 may be absent from the fractional subframe 1 1 10, 1 120). The UE may determine where to monitor the PDCCH 1 1 14, 1 124 for a PDSCH 1 118, 1128 in a fractional subframe 1 1 10, 1 120 either in the fractional subframe 1 1 10, 1 120 or in another subframe, based on the actual available number of OFDM symbols 1 108, 1 128 in a given fractional subframe 11 10, 1 120.

[0083] In one embodiment, the threshold for the available OFDM symbols may be configured as 7 - the number of OFDM symbols in a slot when a normal cyclical prefix is used. If the number of OFDM symbols in a fractional subframe, excepting the preamble is equal to or greater than 7, then the

(E)PDCCH may be transmitted in the fractional subframe n. Otherwise, the UE may determine that no (E)PDCCH is present.

[0084] In some embodiments, the PDCCH may start from any OFDM symbol immediately following preamble transmission in a first fractional subframe. To further reduce UE complexity, however, in some embodiments restrictions may be specified to limit the PDCCH starting OFDM symbol in a fractional subframe that the UE is to monitor. For instance, the candidate OFDM symbol where PDCCH starts may be limited to even-numbered or odd- numbered OFDM symbols in a fractional frame.

[0085] In some embodiments, a hybrid PDSCH scheduling process may be used. In this process, for a PDSCH in a regular subframe an

(E)PDCCH may be transmitted in the same subframe in an assisting serving cell as configured by higher layer signaling while for a PDSCH in a fractional subframe, an (E)PDCCH may be transmitted in the serving cell where

PDSCH is transmitted.

[0086] Various embodiments may be used to avoid "negative- directional" PDSCH scheduling. "Negative-directional" PDSCH scheduling may occur in situations in which a PDSCH in a fractional subframe n scheduled by (E)PDCCH in a full subframe n+1. In one such embodiment a semi-static resource allocation and MCS scheme, configured by higher layer signaling, may be used for scheduling the PDSCH in fractional subframes. In another embodiment, for the fractional subframe n, the resource allocation and MCS scheme may be scheduled in advance at subframe n-k (where k>=0). The UE may apply the configurations once the fractional resource is available after subframe n-k. Combinations of the above may also be used. For example, an activation PDCCH (possibly with the CRC scrambled with the LAA-RNTI) in full subframe n may contain a resource allocation and a MCS scheme for PDSCH transmission in fractional subframes. Once the UE receives the activation PDCCH, the configured resource allocation and MCS scheme may be used for PDSCH reception in every fractional subframe n+k (where k>=0) until another 'deactivation' PDCCH is received.

[0087] FIGS. 12A- 12C illustrate transport block size determination in fractional subframes in accordance with some embodiments. As shown in FIG. 12A, for PDSCH transmission in regular DL subframes 1210, determination of the transport block size (TBS) 1218 may be based on the combination of the resource allocation size (NPRB) and the MCS index, similar to the current LTE standard. The embodiment in FIG. 12A may cover the TBS determination in subframes from n+2 to n+K-2 illustrated in FIG. 3.

[0088] For a fractional subframe in the LAA system, the number of

OFDM symbols within Part 1 (fractional subframe n) can be dynamically varied from 1 to 13 on a per-LAA-burst basis subject to the clear channel assessment/listen-before-talk characteristics determined by the UE.

Correspondingly, the TBS determination may be further adjusted to account for fewer number of OFDM symbols available for the PDSCH to provide more efficient LAA transmission. Based on the above analysis, two cases may be considered for TBS mapping adjustment in LAA systems: a fractional subframe case, as shown in FIG. 12B, and an extended subframe case, as shown in FIG. 12C. In FIG. 12B, the first and last fractional subframes 1220, 1230 (Part 1 and Part 3, respectively) may respectively contain different PDSCHs of the same or different TBSs 1228, 1238. In FIG. 12C, the extended subframe 1240 may contain an extended PDSCH 1248.

[0089] In the current LTE system, the TBS may be obtained using two parameters (ITBS, NPRB), which can be obtained through the detected DCI. For TBS mapping in a fractional subframe or an extended subframe, the NPRB used for mapping TBS may be further scaled by a factor K before TBS determination. In more detail, the scaling factor can be first chosen as a function of the number of OFDM symbols. Thus, K

where Nj^"or N^^ _b ³ is the number of OFDM symbols in Part 1 or Part 3 respectively. N g may be calculated using N g = max{ N _PRB x K T, 1} and (ITBS, ) is used to map the TBS of the PDSCH in fractional subframe.

[0090] To calculate the scaling factor K various embodiments may be used. In one embodiment, for fractional subframe mapping: K = - X)/Y or K = (N^ _b ³ - X)/Y, depending on subframe. For extended subframe mapping: K = 1+ (N^m" " ^X )/Y or K = 1+ (N^ _b ³ - X)/Y, depending on subframe. In either case, X may be determined to reflect the control channel and reference signal overhead in a given fractional subframe. Y may be fixed in the specification, such as 12, or statistically configured by the eNB. In another embodiment, a number of constant values may be defined for TBS mapping, where each value may correspond to a specific range of OFDM symbols in Part 1 or Part 3. For instance: Kl may be used if N^y^ ¹ <L1 or

N!y ? < LI , K2 may be used if Ll< N^ ¹ < L2 or LI < Λ¾ ³ < L2, K3 may be used if L2< N^ ¹ < L3 or L2< Ν ^ ³ < L3 .. . In one non-limiting exam le Kl=0.1 if N^ ¹ < 3, K2 = 0.375 if 3< N^ ¹ < 9, K3 = 0.75 if 9< <14... The K and L values for the fractional subframes (Part 1 and Part 3) may be the same or one or more may be different. Alternatively, a new TBS table may be defined. For example, additional TBS sizes may be provided considering a new number of REs/PRB pair on the unlicensed spectrum.

[0091] FIG. 13 illustrates a flowchart of a method of PDSCH scheduling in accordance with some embodiments. The method shown in FIG. 13 may be used by the UEs 102 and/or eNBs 104 in any of FIGS. 1 - 12D, with the appropriate operations added or eliminated. In different embodiments, the operations may occur in a different order than that shown in FIG. 13.

[0092] The eNB may be in communication with the UE using carrier aggregation. The eNB may communicate with the UE using both licensed and unlicensed spectrum. At operation 1302, the eNB may use clear channel assessment (CCA) to assess the channel providing the carriers for the carrier aggregation in the LAA serving cell and obtain channel access. At this point, the eNB may determine whether the subframe boundaries are aligned between the LAA serving cell and the assisted serving cell (licensed band), and thus whether a fractional subframe is present.

[0093] The eNB may then attempt to schedule a downlink data transmission in a PDSCH of the fractional subframe. At operation 1304, the eNB may determine whether to scale TBS mapping in the fractional subframe (or an extended subframe containing a fractional subframe). Thus, the number of resource elements scheduled in the PDSCH of the fractional subframe may be less than that of a full subframe.

[0094] At operation 1306, in response to the eNB determining that scaling is to be used, the NPRB used for mapping TBS may be scaled before scheduling the resource elements in the PDCCH. In some embodiments, the same scaling may be performed for the last subframe prior to subframe boundary alignment, which may be a fractional frame, as for the first, fractional, subframe. In some embodiments, the scaling between the two fractional subframes may be different. The scaling between the fractional subframes may be independent of each other. The scaling in one or both of the fractional subframes may be based on the number of OFDM symbols in the particular fractional subframe and/or the PDSCH rank.

[0095] Whether or not scaling is to be used, the eNB may also determine at operation 1308 whether cross-carrier or self-carrier scheduling is to be used. This is to say that the eNB may determine whether scheduling for the fractional subframes and/or full subframes in the LAA serving cell is to be provided using resources associated with the assisted serving cell (cross-carrier) or using resources associated with the LAA serving cell (self-carrier). Scheduling may remain the same from the first fractional subframe through the last fractional subframe, or may change. For example, the fractional subframes may use cross- carrier scheduling while the full subframes may use self-carrier scheduling. Alternately, one of the fractional subframes may use cross-carrier scheduling while the other uses self-carrier scheduling. Some (none to all) full subframes may similarly use self-carrier scheduling while others use cross-carrier scheduling. [0096] In response to determining at operation 1308 that cross-carrier scheduling is to be used for the fractional subframe, at operation 1310, the eNB may transmit the PDSCH scheduling using one or more DCI formats on the assisted serving cell. Resource elements in the PDCCH of the first full subframe may be formed in accordance with the DCI format or resource elements in an ePDCCH of the first full subframe may be formed in accordance with the DCI format. A DCI Format may be used to indicate a PDSCH for each of the fractional subframe and full subframe, having independent MCS and resource allocation settings, or a single DCI format may be used indicate a PDSCH for both of the fractional subframe and full subframe. The DCI format may be a legacy DCI format with an additional bit or a concatenated joint DCI format, such that each PDSCH is able to have independent MCS and resource allocation settings, or a legacy DCI format in which the MCS and resource allocation settings are the same. In the last case, the resource elements may map across the fractional subframe and full subframe to form a PDSCH of an extended subframe. In some embodiments, rather than using the PDCCH or ePDCCH of the first full subframe, the DCI format may occur in the full subframe of the assisting serving cell that overlaps the fractional subframe of the LAA serving cell.

[0097] In response to determining at operation 1308 that self-carrier scheduling is to be used for the fractional subframe, at operation 1312, the eNB may determine whether conditional self-scheduling is to occur. This is to say that the eNB may determine whether PDSCH scheduling is to occur in the fractional subframe or in the full subframe. The eNB may make this determination based on whether the available OFDM symbols for LAA data transmission within the fractional subframe is at least a threshold. The threshold may be predetermined or may be configurable via higher layer signaling.

[0098] In response to determining at operation 1312 that self-carrier scheduling for the fractional subframe is to be used in the fractional subframe, at operation 1314, the eNB may transmit the PDCCH or ePDCCH in the fractional subframe using a legacy DCI format. The PDCCH may start from a predetermined OFDM symbol following the preamble. [0099] In response to determining at operation 1312 that self-carrier scheduling for the fractional subframe is to be used in the full subframe, at operation 1316, the eNB may transmit the PDCCH in the first full subframe after the fractional subframe using a legacy DCI format. Similar to the above, the eNB may transmit the PDSCH scheduling using one or more DCI formats. Resource elements in the PDCCH of the first full subframe may be formed in accordance with the DCI format. A DCI Format may be used to indicate a PDSCH for each of the fractional subframe and full subframe, having independent MCS and resource allocation settings, or a single DCI format may be used indicate a PDSCH for both of the fractional subframe and full subframe. The DCI format may be a legacy DCI format with an additional bit or a concatenated joint DCI format, such that each PDSCH is able to have independent MCS and resource allocation settings, or a legacy DCI format in which the MCS and resource allocation settings are the same.

[00100] Thus, in some embodiments, an eNB may transmit and a UE receive a PDCCH or EPDCCH that schedules a PDSCH in a fractional subframe of a LAA serving cell on an unlicensed frequency band. The eNB may subsequently transmit and the UE subsequently receive the PDSCH in the fractional subframe of the LAA serving cell based on the PDCCH/EPDCCH. In addition, for TBS mapping in a fractional subframe or an extended subframe, the NPRB used for mapping TBS may be scaled by a factor K before TBS determination based on the number of OFDM symbols. For a given number of OFDM symbols in a fractional subframe, more than one scaling factor may also be provided. For instance, one factor may provide for rank 1 and 2 PDSCH, and a different factor may be provided for rank 3 and above. One factor may be provided for regular downlink subframes and one or more factors may be provided for fractional subframes, depending on the number of OFDM symbols in these subframes. Alternatively, one factor may be provided for a DL subframe containing a Channel State Information Reference Signal (CSI-RS) and a different factor may be provided for subframes that do not contain a CSI- RS. [00101] In some embodiments, the UE may determine the number of

OFDM symbols of a PDSCH of a first serving cell, which is variably determined by the time domain position of a first reservation signal transmitted in the first serving cell; determining, by the wireless device. The UE may also determine a second serving cell for monitoring a corresponding (e)PDCCH for the PDSCH of the first serving cell based on the detected number of PDSCH symbols in a subframe and the carrier indicator field configuration for the first serving cell. The UE may determine a TBS of the PDSCH in the first subframe in the first serving cell at least based on the detected DCI formats in a second subframe in the corresponding second serving cell and the carrier type of the first serving cell and receive the PDSCH according to the determined TBS. The number of PDSCH symbols may vary from 1 to 14 OFDM symbols by immediately following a first reservation signal. If the UE is not configured with a carrier indicator field for the first serving cell, a second serving cell may be the first serving cell; if the UE is configured with the carrier indicator field for the first serving cell, the second serving cell may be determined based on the value of the carrier indicator field as configured by higher layer signaling. The second serving cell for monitoring the PDCCH for the PDSCH in a subframe is the first serving cell if the number of OFDM symbols of PDSCH in the subframe is less than 14 and a second serving cell for monitoring the PDCCH for the PDSCH in a subframe is determined based on the value of carrier indicator field if the number of PDSCH symbol in the subframe is 14. A first type DCI format may be transmitted in a second subframe in a second serving cell to schedule PDSCH in a first subframe in the first serving cell if the number of PDSCH symbols in the first subframe is less than 14 and a second type DCI format may be transmitted in a first subframe in the second serving cell to schedule the PDSCH in the same subframe in the first serving cell if the number of PDSCH symbols in the first subframe is 14. A first type of DCI format may be transmitted in a second subframe in the second serving cell to schedule the PDSCH in a first subframe and in a second subframe in the first serving cell if the number of PDSCH symbols in the first subframe is less than 14. A first type DCI format may be transmitted in a second subframe in the second serving cell to schedule one PDSCH mapping in the first subframe and the second subframe if the number of PDSCH symbols in the first subframe is less than 14. For the first subframe and second subframe: a second subframe may be subframe n+1 if the starting PDSCH symbol in a first subframe n is larger than 0 or may be subframe n-1 if the starting PDSCH symbol in a first subframe n is 0. The second type DCI format may be one of standard DCI formats used in the 3GPP Release 12 LTE system. The first type DCI format may be a standard DCI format used in the 3 GPP Release 12 LTE system with a CRC scrambled by a distinct RNTI - LAA-RNTI. The first type DCI format may be created by the addition of a 1-bit field to a standard DCI format used in the 3GPP Release 12 LTE system. The TBS may be determined based on a first scheme for a first serving cell, and determined based on a second scheme for a second serving cell. The first scheme may comprise at least a first TBS look-up table, and the second scheme at least a second TBS look- up table different from the first TBS look-up table. The first serving cell may be the on unlicensed spectrum, and the second serving cell may be on the licensed band. The first scheme for TBS determination may be applied for UEs 102 configured with the first serving cell. The first scheme for TBS determination may be configured by higher layer signaling or UE-specific signaling or Cell-specific signaling. A TBS scheme may be determined based on at least two different TBS scheme for a same subframe. A first TBS scheme may be based on a resource allocation size and a MCS value, and a second TBS scheme based on the resource allocation size, the MCS value, and a scaling factor. The scaling factor may be larger than 1 if a PDSCH is mapped on two subframes. The second TBS scheme may comprise a first TBS according to the resource allocation size and the MCS value; and an adjusted TBS calculated by applying the scaling factor to the determined first TBS.

[00102] Example 1 is an apparatus of a user equipment (UE) comprising: a transceiver configured to communicate with an evolved NodeB (eNB) using carrier aggregation having carriers in a Long Term Evolution (LTE) licensed spectrum and carriers in an unlicensed spectrum; and processing circuitry arranged to: configure the transceiver to receive from the eNB one of a physical downlink control channel (PDCCH) and an enhanced PDCCH (ePDCCH) formed in accordance with a Downlink Control Information (DCI) format; determine, using the one of the PDCCH and ePDCCH, whether a physical downlink shared channel (PDSCH) is scheduled in a fractional subframe, the fractional subframe occupying a time between when the carriers in the unlicensed band are able to be accessed by the eNB and a time of an immediately succeeding subframe; and configure the transceiver to receive the PDSCH from the eNB in the fractional subframe in response to a determination that the PDSCH is scheduled in the fractional subframe.

[00103] In Example 2, the subject matter of Example 1 optionally include that the one of the PDCCH and ePDCCH is formed in accordance with the DCI format, and the one of the PDCCH and ePDCCH is transmitted in a first full subframe of the LTE licensed spectrum after the fractional subframe.

[00104] In Example 3, the subject matter of Example 2 optionally include that the DCI format comprises a first DCI format and a second DCI format, and the one of the PDCCH and ePDCCH formed in accordance with the first DCI format schedules the PDSCH in the fractional subframe and the one of the PDCCH and ePDCCH formed in accordance with the second DCI format schedules a PDSCH in a first full subframe of the unlicensed spectrum following the fractional subframe.

[00105] In Example 4, the subject matter of Example 3 optionally include that the first DCI format and second DCI format are pre-3GPP Release 13 DCI formats each containing an additional indication field that indicates which of the fractional subframe and full subframe the one of the PDCCH and ePDCCH is used to schedule the PDSCH transmission.

[00106] In Example 5, the subject matter of Example 4 optionally include that the one of the PDCCH and ePDCCH formed in accordance with the first DCI format has cyclic redundancy check (CRC) bits scrambled by a LAA-Radio Network Temporary Identifier (RNTI) configured by higher layer signaling and the PDCCH formed in accordance with the second DCI format has CRC bits scrambled by a cell RNTI (C-RNTI). [00107] In Example 6, the subject matter of any one or more of Examples

2-5 optionally include that the DCl format comprises a jointly coded DCl format formed by concatenation of two pre-3GPP Release 13 DCl formats, and the one of the PDCCH and ePDCCH formed in accordance with the jointly coded DCl format schedules the PDSCH in the fractional subframe and a PDSCH in a first full subframe of the unlicensed spectrum following the fractional subframe, the PDSCH in the fractional subframe and the PDSCH in the full subframe having at least one of an independent resource allocation and an independent modulation and coding scheme (MCS).

[00108] In Example 7, the subject matter of any one or more of Examples

2-6 optionally include that the DCl format comprises a pre-3GPP Release 13 DCl format, and the one of the PDCCH and ePDCCH formed in accordance with the pre-3GPP Release 13 DCl format schedules the PDSCH in the fractional subframe and a PDSCH in a first full subframe of the unlicensed spectrum following the fractional subframe, the PDSCH in the fractional subframe and the PDSCH in the full subframe having an independent resource allocation and a same modulation and coding scheme (MCS).

[00109] In Example 8, the subject matter of any one or more of Examples

2-7 optionally include that the DCl format comprises a pre-3GPP Release 13 DCl format, and the one of the PDCCH and ePDCCH formed in accordance with the pre-3GPP Release 13 DCl format schedules the PDSCH in the fractional subframe and a PDSCH in a first full subframe of the unlicensed spectrum following the fractional subframe, the PDSCH in the fractional subframe and the PDSCH in the full subframe having a same resource allocation and modulation and coding scheme (MCS).

[00110] In Example 9, the subject matter of any one or more of Examples

2-8 optionally include that the DCl format comprises a pre-3GPP Release 13 DCl format, and the one of the PDCCH and ePDCCH formed in accordance with the pre-3GPP Release 13 DCl format schedules a PDSCH mapped to resource elements in a frequency-first order across both the fractional subframe and the full subframe. [00111] In Example 10, the subject matter of any one or more of

Examples 1-9 optionally include that the one of the PDCCH and ePDCCH is the ePDCCH, the ePDCCH is formed in accordance with pre-3GPP Release 13 DCI format, the ePDCCH is transmitted in a full subframe of the LTE licensed spectrum overlapping the fractional subframe, and another ePDCCH schedules a PDSCH in a first full subframe of the unlicensed spectrum after the fractional subframe.

[00112] In Example 1 1, the subject matter of any one or more of

Examples 1-10 optionally include that the one of the PDCCH and ePDCCH is the ePDCCH, the ePDCCH is formed in accordance with a pre-3GPP Release 13 DCI format, the ePDCCH is transmitted in a full subframe of the LTE licensed spectrum overlapping the fractional subframe, and the ePDCCH schedules a PDSCH mapped to resource elements in a frequency- first order across both the fractional subframe and the full subframe of the unlicensed spectrum.

[00113] In Example 12, the subject matter of any one or more of

Examples 1-1 1 optionally include that the one of the PDCCH and ePDCCH is the PDCCH, and the PDCCH is transmitted in a first full subframe of the unlicensed spectrum following the fractional subframe.

[00114] In Example 13, the subject matter of Example 12 optionally include that the DCI format comprises a first DCI format and a second DCI format, and the PDCCH formed in accordance with the first DCI format schedules the PDSCH in the fractional subframe and the PDCCH formed in accordance with the second DCI format schedules a PDSCH in a first full subframe of the unlicensed spectrum following the fractional subframe.

[00115] In Example 14, the subject matter of Example 13 optionally include that the first DCI format and second DCI format are pre-3GPP Release 13 DCI formats each containing an additional indication field that indicates which of the fractional subframe and full subframe the PDCCH is used to schedule the PDSCH.

[00116] In Example 15, the subject matter of Example 14 optionally include that the PDCCH formed in accordance with the first DCI format has cyclic redundancy check (CRC) bits scrambled by a LAA-Radio Network Temporary Identifier (RNTI) configured by higher layer signaling and the PDCCH formed in accordance with the second DCl format has CRC bits scrambled by a cell RNTI (C-RNTI).

[00117] In Example 16, the subject matter of any one or more of Examples 12-15 optionally include that the DCl format comprises a jointly coded DCl format formed by concatenation of two pre-3GPP Release 13 DCl formats, and the PDCCH formed in accordance with the jointly coded DCl format schedules the PDSCH in the fractional subframe and a PDSCH in the full subframe, the PDSCH in the fractional subframe and the PDSCH in the full subframe having at least one an independent resource allocation and an independent modulation and coding scheme (MCS).

[00118] In Example 17, the subject matter of any one or more of

Examples 12-16 optionally include that the DCl format comprises a pre-3GPP Release 13 DCl format, and the PDCCH formed in accordance with the pre- 3GPP Release 13 DCl format schedules the PDSCH in the fractional subframe and a PDSCH in a first full subframe of the unlicensed spectrum following the fractional subframe, the PDSCH in the fractional subframe and the PDSCH in the full subframe having an independent resource allocation and a same modulation and coding scheme (MCS).

[00119] In Example 18, the subject matter of any one or more of

Examples 12-17 optionally include that the DCl format comprises a pre-3GPP Release 13 DCl format, and the PDCCH formed in accordance with the pre- 3GPP Release 13 DCl format schedules the PDSCH in the fractional subframe and a PDSCH in the first full subframe, the PDSCH in the fractional subframe and the PDSCH in the full subframe having a same resource allocation and modulation and coding scheme (MCS).

[00120] In Example 19, the subject matter of any one or more of

Examples 12-18 optionally include that the DCl format comprises a pre-3GPP Release 13 DCl format, and the PDCCH formed in accordance with the pre- 3GPP Release 13 DCl format schedules a PDSCH mapped to resource elements in a frequency- first order across both the fractional subframe and the first full subframe. [00121] In Example 20, the subject matter of any one or more of

Examples 1-19 optionally include that the one of the PDCCH and ePDCCH is transmitted in the fractional subframe when at least a threshold number of Orthogonal Frequency Division Multiplexed (OFDM) symbols is transmitted in the fractional subframe and the fractional subframe is free from the one of the PDCCH and ePDCCH when the fractional subframe comprises a number of OFDM symbols fewer than the threshold number of OFDM symbols.

[00122] In Example 21, the subject matter of Example 20 optionally include that a starting OFDM symbol of the one of the PDCCH and ePDCCH transmission is limited to a predetermined OFDM symbol.

[00123] In Example 22, the subject matter of any one or more of

Examples 1-21 optionally include that a transport block size of the PDSCH is scaled by the UE based on at least one of a number of OFDM symbols in the fractional subframe, a PDSCH rank, and whether the fractional subframe contains a Channel State Information Reference Signal (CSI-RS).

[00124] In Example 23, the subject matter of any one or more of

Examples 1-22 optionally include, further comprising: an antenna configured to provide communications between the transceiver and the eNB.

[00125] Example 24 is an apparatus of an evolved NodeB (eNB) comprising: a transceiver configured to communicate with user equipment (UE) using carrier aggregation having carriers in a Long Term Evolution (LTE) licensed spectrum and carriers in an unlicensed spectrum; and processing circuitry configured to: determine whether to schedule a physical downlink shared channel (PDSCH) in a fractional subframe occupying a time between when the carriers in the unlicensed band are able to be accessed by the eNB and a time of an immediately succeeding subframe, the fractional subframe occupying a time between when the carriers in the unlicensed band are able to be accessed by the eNB and a time of an immediately succeeding subframe; form one of a physical downlink control channel (PDCCH) and an enhanced PDCCH (ePDCCH) in accordance with a Downlink Control Information (DCI) format to indicate in response to a determination to schedule the PDSCH in the fractional subframe; configure the transceiver to transmit the one of the PDCCH and ePDCCH to the UE; and configure the transceiver to transmit the PDSCH in the fractional subframe as indicated by the one of the PDCCH and ePDCCH to the UE in the fractional subframe.

[00126] In Example 25, the subject matter of Example 24 optionally includes that one of: the one of the PDCCH and ePDCCH is transmitted in a first full subframe of the LTE licensed spectrum after the fractional subframe, the one of the PDCCH and ePDCCH is transmitted in a full subframe of the LTE licensed spectrum overlapping the fractional subframe, and the one of the PDCCH and ePDCCH is transmitted in the fractional subframe when at least a threshold number of Orthogonal Frequency Division Multiplexed (OFDM) symbols is transmitted in the fractional subframe and the fractional subframe is free from the one of the PDCCH and ePDCCH when the fractional subframe contains fewer than the threshold number of OFDM symbols.

[00127] In Example 26, the subject matter of any one or more of

Examples 24-25 optionally include that a transport block size of the PDSCH is scaled based on at least one of a number of OFDM symbols in the fractional subframe and a PDSCH rank.

[00128] Example 27 is a non-transitory computer-readable storage medium that stores instructions for execution by one or more processors of user equipment (UE) to communicate with an evolved NodeB (eNB), the one or more processors to configure the UE to: receive from the eNB one of a physical downlink control channel (PDCCH) and an enhanced PDCCH (ePDCCH) formed in accordance with a Downlink Control Information (DO) format; determine, using the one of the PDCCH and ePDCCH, whether a physical downlink shared channel (PDSCH) is scheduled in a fractional subframe, the fractional subframe occupying a time between when the carriers in the unlicensed band are able to be accessed by the eNB and a time of an

immediately succeeding subframe; determine a transport block size (TBS) of the PDSCH based on the DCI format and a carrier type of the first serving cell; and receive the PDSCH from the eNB according to the determined TBS in the fractional subframe. [00129] In Example 28, the subject matter of Example 27 optionally includes that one of: the one of the PDCCH and ePDCCH is transmitted in a first full subframe of the LTE licensed spectrum after the fractional subframe, the one of the PDCCH and ePDCCH is transmitted in a full subframe of the LTE licensed spectrum overlapping the fractional subframe, and the one of the

PDCCH and ePDCCH is transmitted in the fractional subframe when at least a threshold number of Orthogonal Frequency Division Multiplexed (OFDM) symbols is transmitted in the fractional subframe and the fractional subframe is free from the one of the PDCCH and ePDCCH when the fractional subframe contains fewer than the threshold number of OFDM symbols.

[00130] Example 29 is a method of communication between user equipment (UE) and an evolved NodeB (eNB) using a licensed and unlicensed band, the method comprising: receiving from the eNB one of a physical downlink control channel (PDCCH) and an enhanced PDCCH (ePDCCH) formed in accordance with a Downlink Control Information (DO) format; determining, using the one of the PDCCH and ePDCCH, whether a physical downlink shared channel (PDSCH) is scheduled in a fractional subframe, the fractional subframe occupying a time between when the carriers in the unlicensed band are able to be accessed by the eNB and a time of an

immediately succeeding subframe; determining a transport block size (TBS) of the PDSCH based on the DCI format and a carrier type of the first serving cell; and receiving the PDSCH from the eNB according to the determined TBS in the fractional subframe.

[00131] In Example 30, the subject matter of Example 29 optionally includes that one of: the one of the PDCCH and ePDCCH is transmitted in a first full subframe of the LTE licensed spectrum after the fractional subframe, the one of the PDCCH and ePDCCH is transmitted in a full subframe of the LTE licensed spectrum overlapping the fractional subframe, and the one of the PDCCH and ePDCCH is transmitted in the fractional subframe when at least a threshold number of Orthogonal Frequency Division Multiplexed (OFDM) symbols is transmitted in the fractional subframe and the fractional subframe is free from the one of the PDCCH and ePDCCH when the fractional subframe contains fewer than the threshold number of OFDM symbols.

[00132] Although an embodiment has been described with reference to specific example embodiments, it will be evident that various modifications and changes may be made to these embodiments without departing from the broader spirit and scope of the present disclosure. Accordingly, the specification and drawings are to be regarded in an illustrative rather than a restrictive sense. The accompanying drawings that form a part hereof show, by way of illustration, and not of limitation, specific embodiments in which the subject matter may be practiced. The embodiments illustrated are described in sufficient detail to enable those skilled in the art to practice the teachings disclosed herein. Other embodiments may be utilized and derived therefrom, such that structural and logical substitutions and changes may be made without departing from the scope of this disclosure. This Detailed Description, therefore, is not to be taken in a limiting sense, and the scope of various embodiments is defined only by the appended claims, along with the full range of equivalents to which such claims are entitled.

[00133] Such embodiments of the inventive subject matter may be referred to herein, individually and/or collectively, by the term "invention" merely for convenience and without intending to voluntarily limit the scope of this application to any single invention or inventive concept if more than one is in fact disclosed. Thus, although specific embodiments have been illustrated and described herein, it should be appreciated that any arrangement calculated to achieve the same purpose may be substituted for the specific embodiments shown. This disclosure is intended to cover any and all adaptations or variations of various embodiments. Combinations of the above embodiments, and other embodiments not specifically described herein, will be apparent to those of skill in the art upon reviewing the above description.

[00134] In this document, the terms "a" or "an" are used, as is common in patent documents, to include one or more than one, independent of any other instances or usages of "at least one" or "one or more." In this document, the term "or" is used to refer to a nonexclusive or, such that "A or B" includes "A but not B," "B but not A," and "A and B," unless otherwise indicated. In this document, the terms "including" and "in which" are used as the plain- English equivalents of the respective terms "comprising" and "wherein." Also, in the following claims, the terms "including" and "comprising" are open-ended, that is, a system, UE, article, composition, formulation, or process that includes elements in addition to those listed after such a term in a claim are still deemed to fall within the scope of that claim. Moreover, in the following claims, the terms "first," "second," and "third," etc. are used merely as labels, and are not intended to impose numerical requirements on their objects.

[00135] The Abstract of the Disclosure is provided to comply with 37 C.F.R. § 1.72(b), requiring an abstract that will allow the reader to quickly ascertain the nature of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims. In addition, in the foregoing Detailed Description, it can be seen that various features are grouped together in a single embodiment for the purpose of streamlining the disclosure. This method of disclosure is not to be interpreted as reflecting an intention that the claimed embodiments require more features than are expressly recited in each claim. Rather, as the following claims reflect, inventive subject matter lies in less than all features of a single disclosed embodiment. Thus the following claims are hereby incorporated into the Detailed Description, with each claim standing on its own as a separate embodiment.