WO2017165405A2 - Co-existence of grantless uplink and scheduled transmissions - Google Patents

Abstract

Disclosed herein is an apparatus of a user equipment (UE) configured to communicate with an evolved Node B (eNB). The UE may include memory and processing circuitry coupled to the memory. The processing circuitry may be configured to decode control information received on one or more channels of unlicensed spectrum. The control information includes indication that a grantless uplink (UL) transmission is allowed without a prior UL grant. The processing circuitry is further configured to perform a listen-before-talk (LBT) procedure on the one or more channels of the unlicensed spectrum to determine if one of the channels is available. Upon determining the channel is available, the processing circuitry can encode UL control information and data for transmission using the grantless UL transmission. The grantless uplink transmission is an unscheduled transmission, performed on the channel without an UL grant.

Description

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

Provisional Patent Application Serial No. 62/311,698, filed on March 22, 2016, and entitled "EN ABLING CO-EXISTENCE OF AUTONOMOUS UPLINK TRANSMISSION WITH SCHEDULED TRANSMIS SIGN AT ENB," which is incorporated herein by reference in its entirety.

TECHNICAL FIELD

[0002] Embodiments pertain to wireless communications. Some embodiments relate to wireless networks including 3 GPP (Third Generation Partnership Project) networks, 3GPP LTE (Long Term Evolution) networks, 3 GPP LTE- A (LTE Advanced) networks, MulteFire networks, and 5G networks, although the scope of the embodiments is not limited in this respect . Some embodiments relate to a grantless (or autonomous) uplink transmission (GUL) by user equipment (UE). Some embodiments relate to enabling coexistence of grantless (or autonomous) uplink transmissions with scheduled transmissions.

BACKGROUND

[0003] With the increase in different types of devices communicating with various network devices, usage of 3GPP LTE systems has increased. The penetration of mobile devices (user equipment or UEs) in modern society has continued to drive demand for a wide variety of networked devices in a number of disparate environments. The use of networked UEs using 3 GPP LTE systems has increased in all areas of home and work life. Fifth generation (5G) wireless systems are forthcoming, and are expected to enable even greater speed, connectivity, and usability.

[0004] LTE and LTE-advanced are standards for wireless communications of high-speed data for user equipment (UE) such as mobile telephones. In LTE-Advanced and various wireless systems, carrier aggregation is a technology where multiple carrier signals operating on different frequencies may be used to carry communications for a single UE, thus increasing the bandwidth available to a single device. In some embodiments, carrier aggregation may be used where one or more component carriers operate on unlicensed frequencies.

[0005] The explosive wireless traffic growth leads to a need of rate improvement. With mature physical layer techniques, further improvement in the spectral efficiency will be marginal. On the other hand, the scarcity of licensed spectrum in low frequency bands results in a deficit in the data rate boost. Thus, there are emerging interests in the operation of LTE systems in the unlicensed spectrum. As a result, an important enhancement for LTE in 3 GPP Release 13 has been to enable its operation in the unlicensed spectrum via Licensed- Assisted Access (LAA), which expands the system bandwidth by utilizing the flexible carrier aggregation (CA) framework introduced by the LTE-Advanced system. Rel- 13 LAA system focuses on the design of DL operation on unlicensed spectrum via CA, while Rel- 14 enhanced LAA (eLAA) system focuses on the design of UL operation on unlicensed spectrum via CA. Further enhanced operation of LTE systems in the unlicensed spectrum is expected in future releases and 5G systems. Potential LTE operation in the unlicensed spectrum includes (and is not limited to) the LTE operation in the unlicensed spectrum via dual connectivity (DC), or DC-based LAA, and the standalone LTE system in the unlicensed spectrum, where LTE-based technology solely operates in unlicensed spectrum without requiring an "anchor^'" in the licensed spectrum, called MulteFire. MulteFire, combines the performance benefits of LTE technology with the simplicity of Wi- Fi-like deployments, is envisioned as a significantly important technology component to meet the ever-increasing wireless traffic,

BRIEF DESCRIPTION OF THE FIGURES [0006] 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. Some embodiments are illustrated by way of example, and not limitation, in the following figures of the accompanying drawings.

[0007] As used herein, the terms "autonomous uplink transmission" and

"grantiess uplink transmission" are interchangeable. [0008] FIG. 1 is a block diagram of a system including an evolved node

B (eNB) and a user equipment (UE) that may operate in a wireless

telecommunications network according to some embodiments described herein.

[0009] FIG. 2 is a block diagram of a User Equipment (LIE) in accordance with some embodiments. [0010] FIG. 3 is a block diagram of an Evolved Node-B (eNB) in accordance with some embodiments,

[0011] FIG. 4 illustrates a grantiess uplink transmission (GUL), in accordance with an example embodiment.

[0012] FIG. 5 illustrates an example grantiess UL transmission (GUL) within a restricted timing window in accordance with an example embodiment.

[0013] FIG. 6A and FIG. 6B illustrate example downlink (DL) transmissions following a grantiess UL transmission, in accordance with an example embodiment.

[0014] FIG. 6C illustrate example downlink (DL) transmissions following a grantiess UL transmission requesting an acknowledgement, in accordance with an example embodiment.

[0015] FIG. 7 and FIG. 8 are flow diagrams illustrating example functionalities for performing grantiess uplink transmission, in accordance with some embodiments.

[0016] FIG. 9 illustrates a block diagram of a communication device such as an eNB or a UE, in accordance with some embodiments.

DETAILED DESCRIPTION

[0017] Embodiments relate to systems, devices, apparatus, assemblies, methods, and computer readable media to enhance wireless communications, and particularly to communication systems that operate with carrier aggregation, license-assisted access (LAA), enhanced LAA (eLAA) and MulteFire communications. The following description and the drawings illustrate specific embodiments to enable those skilled in the art to practice them. Other embodiments can incorporate structural, logical, electrical, process, and other changes. Portions and features of some embodiments can be included in, or substituted for, those of other embodiments, and are intended to cover all available equivalents of the elements described.

[0018] FIG. 1 is a block diagram of a system including an evolved node

B (eNB) and a user equipment (HE) that may operate in a wireless

telecommunications network according to some embodiments described herein. The wireless network system 100 includes a UE 104 and an eNB 120 connected via an air interface 190. UE 104 and eNB 120 communicate using a system that supports carrier aggregation (CA) and the use of unlicensed frequency bands, such that the air interface 190 supports multiple frequency carriers, and licensed as well as unlicensed bands. A component carrier 180 and a component carrier 185 are illustrated in FIG. 1. Although two component carriers are illustrated, various embodiments may include any number of two or more component carriers. Various embodiments may function with any number of licensed channels and any number of unlicensed channels. [0019] Additionally, in various embodiments described herein, at least one of the component carriers 180, 185 of the air interface 190 comprises a carrier operating in an unlicensed frequency, referred to herein as an unlicensed carrier. An "unlicensed carrier" or "unlicensed frequency" refers to a range of radio f equencies that are not exclusively set aside for the use of the system. Some frequency ranges, for example, may be used by communication systems operating under different communication standards, such as a frequency band that is used by both Institute of Electronic and Electrical Engineers (IEEE) 802. 1 1 standards (e.g., "WiFi") and third generation partnership (3GPP) standards, including LTE and LTE- Advanced, as well as enhancements to LTE (as discussed herein below). By contrast, a "licensed channel" or "licensed spectrum" operates under a particular standard, with limited concern that other unexpected signals operating on different standards will be present. [0020] Communication over an LTE network may be split up into 10ms frames, each of which contains ten lms subframes. Each subframe, in turn, may contain two slots of 0.5ms. Each slot may contain 6-7 symbols, depending on the system used. A resource block (RB) (also called physical resource block (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. In Frequency Division Duplexed (FDD) mode, both the uplink and downlink frames may be 10ms and may be 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 may be multiplexed in the time domain. A downlink resource grid may be used for downlink transmissions from an eNB to a UE. The grid may be a time- frequency grid, which is the physical resource in the downlink in each slot. Each column and each row of the resource grid may correspond to one OFDM symbol and one OFDM subcarrier, respectively. The duration of the resource grid in the time domain may correspond to one slot. The smallest time-frequency unit in a resource grid may be denoted as a resource element. Each resource grid may comprise a number of the above resource blocks, which describe the mapping of certain physical channels to resource elements. Each resource block may comprise 12 (subcarriers) * 14 (symbols) =168 resource elements.

[0021] In some embodiments, a downlink resource grid may be used for downlink transmissions from the eNB 120 to the UE 104, while uplink transmission from the UE 104 to the eNB 120 may utilize similar techniques. The grid may be a time-frequency grid, called a resource grid or time-frequency resource grid, which is the physical resource in the downlink in each slot. Such a time-frequency plane representation is a common practice for OFDM systems, which makes it intuitive for radio resource allocation. Each column and each row of the resource grid correspond to one OFDM symbol and one OFDM subcarrier, respectively. The duration of the resource grid in the time domain corresponds to one slot in a radio frame. The smallest time-frequency unit in a resource grid is denoted as a resource element (RE). Each resource grid comprises a number of resource blocks (RBs), which describe the mapping of certain physical channels to resource elements. Each resource block comprises a collection of resource elements in the frequency domain and may represent the smallest quanta of resources that currently can be allocated. There are several different physical downlink channels that are conveyed using such resource blocks. Two example physical downlink channels are the physical downlink shared channel and the physical down link control channel.

[0022] There may be several different physical downlink channels that are conveyed using such resource blocks. Two of these physical downlink channels may be the physical down link control channel (PDCCH) and the physical downlink shared channel (PDSC ). Each subframe may be partitioned into the PDCCH and the PDSCH.

[0023] The physical downlink shared channel (PDSCH) carries user data and higher-layer signaling to the UE 104. The physical downlink control channel (PDCCH) carries information about the transport format and resource allocations related to the PDSCH channel, among other things. It also informs the UE 104 about the transport format, resource allocation, and hybrid automatic repeat request (HARQ) information related to the uplink shared channel.

Typically, downlink scheduling (e.g., assigning control and shared channel resource blocks to UE 104 within a cell) may be performed at the eNB 120 based on channel quality information fed back from the UE 104 to the eNB 120, and then the downlink resource assignment information may be sent to the UE 104 on the control channel (PDCCH) used for (assigned to) the UE 104.

[0024] The PDCCH uses CCEs (control channel elements) to convey the control information. Before being mapped to resource elements, the PDCCH complex-valued symbols are first organized into quadruplets, which are then permuted using a sub-block inter-leaver for rate matching. Each PDCCH is transmitted using one or more of these control channel elements (CCEs), where each CCE corresponds to nine sets of four physical resource elements known as resource element groups (REGs). Four QPSK symbols are mapped to each REG. The PDCCH can be transmitted using one or more CCEs, depending on the size of downlink control information (DCI) and the channel condition. There may be four or more different PDCCH formats defined in LTE with different numbers of CCEs (e.g., aggregation level, L=T, 2, 4, or 8). [0025] Embodiments described herein may fail in the scope of the standalone system in the unlicensed spectrum including but not limited to MulteFire (MF), the next release LAA system (e.g., eLAA), which enables UL operation, 5G unlicensed system, and DC based LAA system. An unlicensed frequency band of current interest in 3GPP is the 5 GHz band, which has wide spectrum with global common availability. The 5 GHz band in the US is governed by Unlicensed National Information Infrastructure (UNII) rules by the Federal Communications Commission (FCC). The main incumbent system in the 5 GHz band is the Wireless Local Area Networks (WLAN), specifically communication networks based on the IEEE 802.11 a/n/ac technologies. Since WLAN systems are widely deployed both by individuals and operators for carrier-grade access service and data offloading, Listen-Before-Talk (LBT) is considered as a mandatory feature of Rel-13 LAA and Rel-14 eLAA system for fair coexistence with the incumbent system. [0026] LBT is a procedure whereby radio transmitters first sense the medium and transmit only if the medium is sensed to be idle. In an example, a scheduled based UL LAA design can include UL PUSCH transmission based on an explicit UL grant transmission via PDCCH (e.g. via DCI format OA/OB). The UL grant transmission is performed after completing an LBT procedure at an eNB on the component carrier over which PUSCH transmission is expected. After receiving the UL grant, the scheduled UE is expected to perform a short LBT or Cat 4 LBT during the allocated time interval. If the LBT is successful at the scheduled UE, then UE can transmit PUSCH on the resources indicated by the UL grant. [0027] However, UL performance in the unlicensed spectrum (e.g., during MulteFire operation exclusively in the unlicensed spectrum) can be significantly degraded due to the double LBT requirements at both the eNB side (e.g., when sending the UL grant) and at the scheduled UE side (e.g., before UE's transmission). This performance degradation can be typical in instances when a scheduled system (e.g., LTE-based system) coexists with a non- scheduled autonomous system, i.e., Wi-Fi. In some instances, LTE-based systems may also use a 4-subframe processing delay, whereby the initial 4 subframes in a transmission burst cannot be configured to UL as the UL grants are unavailable for those subframes within the same transmission burst. The 4- subframe delay requirement may also result in processing delay for LTE systems operating in the unlicensed spectrum.

[0028] In example embodiments, in order to improve the communication system performance in the unlicensed spectrum (e.g., due to the double LBT requirement as well as the 4-subframe processing delay), the UE can perform grantless UL transmission where the eNB does not transmit UL grant for PUSCH transmissions by the UE. In this regard, the double LBT requirement can be alleviated when grantless UL transmission by the UE takes place, since the eNB will not perform LBT and LBT can be performed only by the UE.

Since the UE performing grantless UL transmission does not have to wait for an UL grant by the eNB, the additional 4-subframe delay for accessing a channel for UL transmission will be eliminated as well, contributing to further performanc e i m provem ent . [002 1 Embodiments described herein for coexistence may operate within the wireless network system 100. In the wireless network system 100, the UE 04 and any other UE in the system may be, for example, laptop computers, smartphones, tablet computers, printers, machine-type devices such as smart meters or specialized devices for healthcare monitoring, remote security surveillance systems, intelligent transportation systems, or any other wireless devices with or without a user interface. The eNB 120 provides the UE 104 network connectivity to a broader network (not shown). The UE 104 connectivity is provided via the air interface 190 in an eNB service area provided by the eNB 120. In some embodiments, such a broader network may be a wide area network operated by a cellular network provider, or may be the Internet. Each eNB service area associated with the eNB 120 is supported by antennas integrated with the eNB 120, The service areas may be divided into a number of sectors associated with certain antennas. Such sectors may be physically associated with fixed antennas or may be assigned to a physical area, with tunable antennas or antenna settings adjustable in a beamforming process used to direct a signal to a particular sector. One embodiment of the eNB 120, for example, includes three sectors each covering a 120-degree area with an array of antennas directed to each sector to provide a 360-degree coverage around the eNB 120,

[0030] The UE 104 includes control circuitry 105 coupled with transmit circuitry 10 and receive circuitry 1 5. The transmit circuitry 1 0 and receive circuitry 115 may each be coupled with one or more antennas. The control circuitry 105 may be adapted to perform operations associated with wireless communications using carrier aggregation. The transmit circuitry 110 and receive circuitry 115 may be adapted to transmit and receive data, respectively. The control circuitry 105 may be adapted or configured to perform various operations such as those described elsewhere in this disclosure related to a UE. The transmit circuitry 110 may transmit a plurality of multiplexed uplink physical channels. The plurality of uplink physical channels may be multiplexed according to time division multiplexing (TDM) or frequency division multiplexing (FDM) along with carrier aggregation. The transmit circuitry 1 10 may be configured to receive block data from the control circuitry 105 for transmission across the air interface 190. Similarly, the receive circuitry 1 15 may receive a plurality of multiplexed downlink physical channels from the air interface 190 and relay the physical channels to the control circuitry 105. The uplink and downlink physical channels may be multiplexed according to FDM. The transmit circuitry 110 and the receive circuitry 115 may transmit and receive both control data and content data (e.g., messages, images, video, et cetera) structured within data blocks that are carried by the physical channels.

[0031] FIG. 1 also illustrates the eNB 120, in accordance with various embodiments. The eNB 120 circuitry may include control circuitry 155 coupled with transmit circuitry 160 and receive circuitry 165. The transmit circuitry 160 and receive circuitry 165 may each be coupled with one or more antennas that may be used to enable communications via the air interface 190.

[0032] The control circuitry 155 may be adapted to perform operations for managing channels and component carriers used with various UEs. The transmit circuitry 160 and receive circuitry 165 may be adapted to transmit and receive data, respectively, to and from any UE connected to the eNB 120. The transmit circuitry 160 may transmit downlink physical channels comprised of a plurality of downlink subframes. The receive circuitry 165 may receive a plurality of uplink physical channels from various UEs including the UE 104. The plurality of uplink physical channels may be multiplexed according to FDM in addition to the use of carrier aggregation.

[0033] As mentioned above, the communications across the air interface 190 may use carrier aggregation, where multiple different component carriers 80, 185 can be aggregated to carry information between the UE 104 and the eNB 120. Such component carriers 180, 185 may have different bandwidths, and may be used for uplink communications from the UE 104 to the eNB 120, downlink communications from the eNB 120 to the UE 104, or both. Such component carriers 180, 185 may cover similar areas, or may cover different but overlapping sectors. The radio resource control (RRC) connection may be handled by only one of the component carrier cells, which may be referred to as the primary component carrier, with the other component carriers referred to as secondary component carriers. In some embodiments, the primary component carrier is provided by a primary cell (PCeli) and may be operating in a licensed band to provide efficient and conflict-free communications. This primary channel may be used for scheduling other channels including unlicensed channels. In this regard, the PCell is the main cell with which the UE 104 communicates and maintains its connection with the network. [0034] In an example, one or more secondary cells (SCells) can also be allocated and activated to UEs supporting carrier aggregation using licensed and unlicensed bands (e.g., UL and DL communication based on eLAA).

[0035] In operation, the wireless telecommunications network 100 may include a capability for the eNodeB 120 and the UE 104 to communicate over licensed spectrum. The wireless telecommunications network 100 may also include a capability for the eNodeB 120 and the UE 104 to communicate over unlicensed spectrum (e.g., one or more 5GHz bands). In some examples of contemporaneous transmission over licensed and unlicensed spectrum, the licensed spectrum transmission may be a primary cell (PCell) transmission, and the unlicensed spectrum transmissions may be secondary cell (SCell) transmissions. For communication over the PCell and the SCell, the wireless telecommunications network 100 may use a self-contained frame structure in which control signaling and data may be transmitted with a single subframe in a time-division multiplexing (TDM) manner.

[0036] In some embodiments, the wireless telecommunications network

100 may include a capability for the eNodeB 120 and the UE 104 to

communicate only over unlicensed spectrum (e.g., MulteFire communication). Additionally, the UE can be configured to perform grantless uplink

transmissions, as described in greater detail in reference to FIGS. 4-9.

[0037] As used herein, the term circuitry may refer to, be part of or include an Application Specific Integrated Circuit (ASIC), an electronic circuit, a processor (shared, dedicated, or group), or memory (shared, dedicated, or group) that executes one or more software or firmware

programs, a combinational logic circuit, or other suitable hardware

components that provide the described functionality. In some embodiments, the circuitry may be implemented in, or functions associated with the circuitry may be implemented by, one or more software or firmware modules. In some embodiments, circuitry may include logic, at least partially operable in hardware. Embodiments described herein may be implemented into a system using any suitably configured hardware or software.

[0038] FIG. 2 is a functional diagram of a User Equipment (UE) in accordance with some embodiments. The UE 200 may be suitable for use as a UE 104 as depicted in FIG. 1. 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 multiple antennas 210.Λ-2 1 Oi). coupled together at least as shown. In some embodiments, other circuitry or arrangements may include one or more elements or components of the application circuitry 202, the baseband circuitry 204, the RF circuitry 206 or the FEM circuitry 208, and may also include other elements or components in some cases. As an example, "processing circuitry" may include one or more elements or components, some or all of which may be included in the application circuitry 202 or the baseband circuitry 204. As another example, "transceiver circuitry" may include one or more elements or components, some or all of which may be included in the RF circuitry 206 or the FEM circuitry 208. These examples are not limiting, however, as the processing circuitry or the transceiver circuitry may also include other elements or components in some cases.

[0039] 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 or may include memory/ storage and may be configured to execute instructions stored in the memory/ storage to enable various applications or operating systems to run on the system to perform one or more of the functionalities described herein.

[0040] 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 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, 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, or constellation mapping/demapping functionality. In some embodiments, encoding/decoding circuitry of the baseband circuitry 204 may include Low Density Parity Check (LDPC) encoder/decoder functionality, optionally along-side other techniques such as, for example, block codes, convolutional codes, turbo codes, or the like, which may be used to support legacy protocols. Embodiments of modulation/demodulation and

encoder/decoder functionality are not limited to these examples and may include other suitable functionality in other embodiments.

|0041| 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), 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 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 chip (SOC).

[0042] 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) or other wireless metropolitan area networks WMAN), a wireless local area network (WLANf), 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 muiti- mode baseband circuitry,

[0043] 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-eonvert baseband signals provided by the baseband circuitry 204 and provide RF output signals to the FEM circuitry 208 for transmission.

[0044] 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. 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. [0045] 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 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 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.

[0046] 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 digitai-to-analog converter (DAC) circuitry and the baseband circuitry 204 may include a digital baseband interface to communicate with the RF circuitry 206. 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.

[0047] 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-si gma synthesizer, a frequency multiplier, or a synthesizer comprising a phase-locked loop with a frequency divider. 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. 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.

[0048] 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 (DP A). In some embodiments, the DMD may be configured to divide the input signal by either N or N+l (e.g., based on a cany 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.

[0049] 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 (fLO). In some embodiments, the RF circuitry 206 may include an IQ/polar converter. [0050] FEM circuitry 208 may include a receive signal path, which may include circuitry configured to operate on RF signals received from one or more of the antennas 210A-D, 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 210A- D. [0051] 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 F 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. In some embodiments, the UE 200 may include additional elements such as, for example, memory/storage, display, camera, sensor, or input/output (I/O) interface.

[0052] FIG. 3 is a functional diagram of an Evolved Node-B (eNB) in accordance with some embodiments. It should be noted that in some

embodiments, the eNB 300 may be a stationary non- mobile device. The eNB 300 may be suitable for use as an eNB 120 as depicted in FIG. 1 . The components of eNB 300 may be included in a single device or a plurality of devices. The eNB 300 may include physical layer (PHY) circuitry 302 and a transceiver 305, one or both of which may enable transmission and reception of signals to and from the UE 200, other eNBs, other UEs or other devices using one or more antennas 301 A-B. As an example, the physical layer circuitry 302 may perform various encoding and decoding functions that may include formation of baseband signals for transmission and decoding of received signals. For example, physical layer circuitry 302 may include LDPC encoder/decoder functionality, optionally along-side other techniques such as, for example, block codes, convolutional codes, turbo codes, or the like, which may be used to support legacy protocols. Embodiments of modulation/demodulation and encoder/decoder functionality are not limited to these examples and may include other suitable functionality in other embodiments. As another example, the transceiver 305 may perform various transmission and reception functions such as conversion of signals between a baseband range and a Radio Frequency (RF) range. Accordingly, the physical layer circuitry 302 and the transceiver 305 may be separate components or may be part of a combined component. In addition, some of the described functionality related to transmission and reception of signals may be performed by a combination that may include one, any or ail of the physical layer circuitry 302, the transceiver 305, and other components or layers. The eNB 300 may also include medium access control layer (MAC) circuitry 304 for controlling access to the wireless medium. The eNB 300 may also include processing circuitry 306 and memory 308 arranged to perform the operations described herein. The eNB 300 may also include one or more interfaces 310, which may enable communication with other components, including other eNB 04 (FIG. 1 ), components in the EPC 120 (FIG. 1) or other network components. In addition, the interfaces 310 may enable communication with other components that may not be shown in FIG. 1, including components external to the network. The interfaces 310 may be wired or wireless or a combination thereof,

[0053] The antennas 210A-D (in the UE) and 301A-B (in the eNB) may comprise one or more directional or omnidirectional antennas, including, for example, dipole antennas, monopoie antennas, patch antennas, loop antennas, microstrip antennas or other types of antennas suitable for transmission of RF signals. In some multiple-input multiple-output (MIMO) embodiments, the antennas 210A-D, 301 A-B may be effectively separated to take advantage of spatial diversity and the different channel characteristics that may result. [0054] In some embodiments, the UE 200 or the eNB 300 may be a mobile device and may be a portable wireless communication device, such as a personal digital assistant (PDA), a laptop or portable computer with wireless communication capability, a web tablet, a wireless telephone, a smartphone, a wireless headset, a pager, an instant messaging device, a digital camera, an access point, a television, a wearable device such as a medical device (e.g., a heart rate monitor, a blood pressure monitor, etc.), or other device that may receive or transmit information wirelesslv. In some embodiments, the UE 200 or eNB 300 may be configured to operate in accordance with 3 GPP standards, although the scope of the embodiments is not limited in this respect. Mobile devices or other devices in some embodiments may be configured to operate according to other protocols or standards, including IEEE 802.11 or other IEEE standards. In some embodiments, the UE 200, eNB 300 or other device may include one or more of a keyboard, a display, a non- volatile memory port, multiple antennas, a graphics processor, an application processor, speakers, and other mobile device elements. The display may be an LCD screen including a touch screen.

[0055] Although the UE 200 and the eNB 300 are each illustrated as having several separate functional elements, one or more of the functional elements may be combined and may be implemented by combinations of software-configured elements, such as processing elements including digital signal processors (DSPs), or other hardware elements. For example, some elements may comprise one or more microprocessors, DSPs, field- programmable gate arrays (FPGAs), application specific integrated circuits (ASICs), radio-frequency integrated circuits (RFICs) and combinations of various hardware and logic circuitry for performing at least the functions described herein. In some embodiments, the functional elements may refer to one or more processes operating on one or more processing elements. [0056] Embodiments may be implemented in one or a combination of hardware, firmware and software. Embodiments may also be implemented as instructions stored on a computer-readable storage device, which may be read and executed by at least one processor to perform the operations described herein. A computer-readable storage device may include any non-transitory mechanism for storing information in a form readable by a machine (e.g., a computer). For example, a computer-readable storage device may include readonly memory (ROM), random-access memory (RAM), magnetic disk storage media, optical storage media, flash-memory devices, and other storage devices and media. Some embodiments may include one or more processors and may be configured with instructions stored on a computer-readable storage device.

[0057] It should be noted that in some embodiments, an apparatus used by the UE 200 or eNB 300 may include various components of the UE 200 or the eNB 300 as shown in FIG. 2 and FIG. 3. Accordingly, techniques and operations described herein that refer to the UE 200 (or 104) may be applicable to an apparatus for a UE. In addition, techniques and operations described herein that refer to the eNB 300 (or 120) may be applicable to an apparatus for an eNB. [0058] Even though specific durations (e.g., time interval duration, transmission time etc.) and specific bit sequence sizes are mentioned herein, the disclosure may not be limited in this regard, and specific numbering designations are for illustrative purposes only. [0059] FIG. 4 illustrates a grantless uplink transmission (GUI.), in accordance with an example embodiment. Referring to FIG. 4, the

communications 400 may take place in a MulteFire system, e.g., between the UE 104 and the eNB 120. The UE 104 and the eNB 120 may communicate on one or more communication bands in the unlicensed spectrum, which can be shared with the Wi-Fi station (e.g., access point) 402,

[0060] In an example, the UE 104 can be configured to communicate using scheduled transmissions. For example, the eNB 120 can send a downlink (DL) burst 404 (e.g., on a PUSCH in unlicensed spectrum). The DL burst 404 can include an UL grant for a scheduled transmission by the UE. The UE can then perform the scheduled transmission of the UL burst 406.

[0061] In an example, the UE 104 can perform a grantless UL

transmission (GUL) 410 using a PUSCH of the unlicensed spectrum. Prior to performing the GUL, the UE 104 can perform channel contention (e.g., listen- before-talk, or LBT 408) without explicit indication from the eNB 120. The LBT can be a Category 4 LBT or a single shot LBT. After the LBT is performed, the UE 104 can send data and/or UL control information via the GUL 410 on the PUSCH. The UL control information can include the UE identity (UEID) information, a modulation coding scheme (MCS) used by the UE, redundancy version (RV), and/or new data indicator (NDI). In response, the eNB 120 can communicate downlink (DL) control information 412, which can include acknowledgement (ACK)/non-acknowledgement (NACK) for the GUL 410, UL channel state information (CSI) and/or MCS indication for the UE.

[0062] In an example, the eNB may transmit the DL control information

412 A, after the GUL 410 and within the time interval reserved for transmission by the UE as a result of the LBT 408. In another example, the eNB may transmit the DL control information 412 in subsequent subframes, e.g., prior to a scheduled DL burst transmission 414 after performing LBT. [0063] FIG. 4 additionally illustrates eNB DL transmission burst 414, with an UL grant, and the subsequent UL transmission burst 416 as a result of the grant. A second UE (UE2) can perform an LBT procedure 418 and then a GUL 420, followed by a DL control information transmission 422 by the eNB. [0064] In an example, the eNB 120 can be associated with a cell that includes UEs that can perform grantless UL transmission along with scheduled DL/UL transmissions. One or more of techniques described herein can be used to control the impact of grantless uplink transmissions on scheduled

transmissions. [0065] In an example, the eNB 120 can use L1 L2 signaling to control which UEs are allowed to transmit autonomously. More specifically, the eNB 120 can transmit downlink control information (DCI) as L I signaling, or radio resource control (RRC) information as L2 signaling to one or more UEs in order to indicate whether grantless uplink transmission is allowed. For example, the L1/L2 signaling can be transmitted on a common physical downlink control channel (cPDCCH) to ail UEs associated with the ceil of the eNB. In instances when L1 /L2 signaling is transmitted on the cPDCCH or as system information, all UEs are notified of whether or not grantless uplink transmissions are allowed. In another example, LI or L2 signaling can be transmitted to specific UE via a physical downlink control channel (PDCCH) or UE dedicated RRC signaling, to notify the specific UE of whether or not grantless uplink transmission is allowed. Additionally, LI or L2 signaling sent on PDCCH can be used to notify a group of UEs of whether or not grantless uplink transmission is allowed.

[0066] In an example, the eNB 120 can control the potential number of UEs based on various indications from the UEs. In instances when a UE has UL data to transmit, the UE 104 may communicate a buffer status report (BSR) which indicates traffic status at the UE. The eNB 120 can then send LI or L2 signaling to the UE allowing grantless uplink transmissions based on the BSR.

[0067] In another example the eNB 120 can determine whether the UE needs grantless transmission based on the congestion experience at the UE. In instances when a UE has experienced high congestion in channel access, the ENB may improve the UL transmission opportunities by enabling the UE with grantless uplink transmission. For example, the congestion status can be based on the rate of UL grant failure. More specifically, in instances when the UE is not able to transmit scheduled PUSCH transmissions for a certain number of UL grants, the eNB may signal the UE to perform grantless uplink transmission. In this regard, the grantless uplink transmission may improve the UL contention opportunities. In an example, the eNB may signal that UE to perform grantless uplink transmission after a certain number of failed scheduled uplink

transmissions by the UE,

[0068] In an example, the UE can monitor communications on the

CPDCCH from the eNB to determine any ongoing or upcoming scheduled DL or UL transmissions. The UE may then defer its grantless uplink transmissions to avoid any coexistence with scheduled transmissions.

[0069] FIG. 5 illustrates an example grantless UL transmission (GUL) within a restricted timing window in accordance with an example embodiment. Referring to FIG. 5, the communications 500 illustrate how the eNB can restrict operation of nonscheduied communications, such as grantless uplink

transmissions, within a certain known duration. More specifically, the eNB can notify the UE of a discovery reference signal (DRS) transmission window (DTxW) period 502 A of repeating the DTxW 504. The DTxW 504 can be a time interval for transmitting a DRS (e.g., DRS 508). In an example, a paging signal 510 can also be transmitted based on paging occasions initiated by the eNB. The DRS 508 can include, for example, a primary synchronization signal (PSS), a secondary synchronization signal (SSS), system information

communicated on a physical broadcast channel (PBCH), and cell specific reference signals (CRS). The eNB can notify the UE of the allowed grantless transmission interval 506A, which is outside of the restricted DTxW 504 (e.g., 504A). In another example, the eNB can indicate the available time domain resources, e.g. in terms of a set of subframes that can be used for GUL. The RRC signaling can be used for such an indication. The set of subframes available for GUL can be indicated via a bitmap of N bits and the pattern can repeat every N milliseconds (ms). In an example, N=40.

[0070] As seen in FIG. 5, scheduled downlink and uplink transmissions

512 as well as grantless uplink transmissions 514 can take place within the allowed grantless transmission interval 506A. Similarly, the eNB can transmit DRS 516 as well as a portion of a scheduled downlink transmission 518 during the DTxW 504B within the DTxW period 502B. Grantless uplink transmissions 520 can be performed outside of the DTxW 504B. In this regard, by restricting grantless uplink transmissions to time intervals outside of the DTxW, the e B can minimize the impact of grantless uplink transmissions to critical downlink transmissions, such as the DRS transmissions.

[0071] In an example, the maximum duration of the grantless UL transmission can be limited. For example, the eNB can indicate to the UE that the maximum duration for the grantless UL transmission is 4 ms, and the UE can transmit for an interval of 4 ms, after which interval the UE needs to contend again for the channel (and perform LBT).

[0072] In an example, the eNB and/or the UE may sense availability (or absence) of a Wi-Fi station and may activate or deactivate grantless UL transmission based on such availability. For example, the eNB may deactivate grantless UL transmissions in the absence of a Wi-Fi station operating within the unlicensed spectrum within the eNB cell.

[0073] FIG. 6A and FIG. 6B illustrate example downlink (DL) transmissions following a grantless UL transmission, in accordance with an example embodiment. [0074] In a communication environment where scheduled transmissions from the eNB and Wi-Fi stations are predominant, grantless UL transmissions may perform poorly due to less opportunities for the transmission of HARQ ACK/NACK feedback, UL CSI and/or MCS information from the eNB in response to a grantless UL transmission. To increase the transmission opportunity of D L control information, DL control information can follow the GUL and after the eNB performs a single-interval LBT. In an example, no LBT is performed by the eNB for the DL control information if it is within the maximum channel occupancy time (MCOT) initialized by the UE associated to the eNB. For example and referring to the communication 600A in FIG. 6A, a grantless uplink transmission 606 A may take place followed by grantless uplink transmissions 608 A. The downlink control information 61 OA including the ACK/NACK, the UL CSI and/or MCS in response to the grantless uplink transmission 606A may take place after the grantless uplink transmissions 608A. Additionally, the downlink control information 614A in response to the grantless uplink transmissions 608A may experience a delay 620A and can be

communicated after the grantless uplink transmissions 612A. Similarly, the downlink control information 616A in response to the grantless uplink transmissions 612A may experience a delay 622A and can be communicated after the scheduled (or Wi-Fi) transmissions, as illustrated in FIG. 6A. In case the DL control information is transmitted outside a TxOP, e.g. 616A in FIG. 6 A, a Cat-4 LBT is performed for the DL control information transmission.

[0075] Referring to the communication 600B in FIG. 6B, a grantless uplink transmission 602B may take place followed by grantless uplink transmissions 604B. The downlink control information 606B including the ACK/NACK, the UL CSI and/or MCS in response to the grantless uplink transmission 602B may take place after the grantless uplink transmissions 604B. Additionally, the downlink control information 610B in response to the grantless uplink transmissions 604B may experience a delay and can be communicated after the grantless uplink transmissions 608B. Similarly, the downlink control information 614B in response to the grantless uplink transmissions 608B may experience a delay and can be communicated during the schedule DL burst 612B. In these examples, DL control information 606B and 610B can be subject to single-interval LBT if it is within the MCOT initialized by the UE

transmitting 602B/604B/608B GUL, or it can be subject to no LBT if it is within, e.g., 16us from the end of preceding UL transmission and it is within the MCOT initialized by the UE with a GUL transmission. In example of DL control information 614B, as eNB has performed Cat-4 LBT for DL burst 612B, no LBT or single-interval LBT is performed for transmitting DL control information 614B. In case the DL control information (e.g., 614B) is transmitted outside a transmit opportunity (TxOP), a Cat-4 LBT is performed for the DL control information transmission.

[0076] In an example, to reduce the delay in receiving the DL control information from the eNB, the UE may autonomously perform an LBT procedure (e.g., Category 4 LBT) to request feedback for pending HARQ processes (e.g., unacknowledged grantless UL transmissions). This contention can be in addition to eNB's Category 4 LBT contention to transmit the ACK/ ACK feedback. After the UE performs the grantless UL transmission requesting the DL control information, the eNB can transmit HARQ

ACK/NACK immediately with short (or no) LBT procedure, as illustrated with communications 600C in FIG. 6C. [0077] FIG. 6C illustrate example downlink (DL) transmissions following a grantless UL transmission requesting an acknowledgement, in accordance with an example embodiment.

[0078] Referring to the communications 600C in FIG. 6C, a grantless uplink transmission 608C may take place followed by grantless uplink transmissions 610C. The downlink control information 612C including the ACK NACK, the UL CSI and/or MCS in response to the grantless uplink transmission 608 may take place after the grantless uplink transmissions 6 IOC. Additionally, the downlink control information 616C in response to the grantless uplink transmissions 6 IOC may experience a delay and can be communicated after the grantless uplink transmissions 614C. Similarly, the downlink control information in response to the grantless uplink transmissions 614C may experience a delay 626C and can be communicated after the scheduled transmissions 618C and 624C. In an example, in order to reduce the delay in receiving the downlink control information in response to the grantless uplink transmissions 614C, the UE can perform an LBT and a grantless UL

transmission 620C, requesting the DL control information (including

ACK/NACK, the UL CSI and/or MCS in response to the grantless uplink transmissions 614C). The DL control information 622C in response to the grantless uplink transmissions 614C is then communicated after the grantless UL transmission 620C.

[0079] FIG. 7 and FIG. 8 are flow diagrams illustrating example functionalities for performing grantless uplink transmission, in accordance with some embodiments. Referring to FIG. 7, the example method 700 may start at 702, when control information received on one or more channels of unlicensed spectrum may be decoded. The control information may include an indicator that a grantless uplink (UL) transmission is allowed without a prior UL grant. For example, the eNB 120 can use physical layer (i.e. LI) signaling or higher layer signaling (such as DCI or RRC signaling) to indicate to the UE that grantless UL transmissions are allowed within certain resources. At 704, a listen-before-talk (LBT) procedure is performed on the one or more channels of the unlicensed spectrum to determine if one of the unlicensed spectrum channels is available. For example, that UE 104 can perform an LBT procedure 408. At 706, upon determining the channel is available, UL control information and data can be encoded for transmission on a physical uplink shared channel (PUSCH), short physical uplink control channel (sPUCCH) and/or extended PUCCH (ePUCCH) using the grantless UL transmission. For example, the GUL 4 0 can be performed by the UE without prior UL grant by the eNB. In this regard, the grantless uplink transmission 410 is an unscheduled grantless transmission, performed on the available channel of the unlicensed spectrum without an UL grant.

[0080] Referring to FIG. 8, the example method 800 may start at 802, when control information may be encoded for transmission on one or more channels of unlicensed spectrum. For example, the eNB 120 can encode physical layer or higher layer signaling (such as DCI or RRC signaling), which can include indication that a grantless uplink (UL) transmission is allowed without a prior UL grant within certain resources. At 804, UL control information and data can be decoded. The control information and the data can be received on a sPUCCH/ePUCCH and/or physical uplink shared channel (PUSCH) using the grantless UL transmission. For example, the control information and the data can be received from the UE via a grantless uplink transmission, where the grantless uplink transmission is an unscheduled grantless transmission, performed on the one or more channels of the unlicensed spectrum without an UL grant. At 806, an acknowledgement (ACK) feedback or a non-acknowledgement (NACK) feedback can be encoded in response to the grantless uplink transmission. For example, the eNB can encode DL control information 412 A for transmission to the UE, which includes the ACK/NACK indicator, UL CSI and/or MCS information. [0081] FIG. 9 illustrates a block diagram of a communication device such as an eNB or a UE, in accordance with some embodiments. In alternative embodiments, the communication device 900 may operate as a standalone device or may be connected (e.g., networked) to other communication devices. In a networked deployment, the communication device 900 may operate in the capacity of a server communication device, a client communication device, or both in server-client network environments. In an example, the communication device 900 may act as a peer communication device in peer-to-peer (P2P) (or other distributed) network environment. The communication device 900 may be a UE, eNB, PC, a tablet PC, a STB, a PDA, a mobile telephone, a smart phone, a web appliance, a network router, switch or bridge, or any communication device capable of executing instaictions (sequential or otherwise) that specify actions to be taken by that communication device. Further, while only a single

communication device is illustrated, the term "communication device" shall also be taken to include any collection of communication devices that individually or jointly execute a set (or multiple sets) of instructions to perform any one or more of the methodologies discussed herein, such as cloud computing, software as a sendee (SaaS), other computer cluster configurations. [0082] Examples, as described herein, may include, or may operate on, logic or a number of components, modules, or mechanisms. Modules are tangible entities (e.g., hardware) capable of performing specified operations and may be configured or arranged in a certain manner. In an example, circuits may be arranged (e.g., internally or with respect to external entities such as other circuits) in a specified manner as a module. In an example, the whole or part of one or more computer systems (e.g., a standalone, client or server computer system) or one or more hardware processors may be configured by firmware or software (e.g., instructions, an application portion, or an application) as a module that operates to perform specified operations. In an example, the software may reside on a communication device readable medium. In an example, the software, when executed by the underlying hardware of the module, causes the hardware to perform the specified operations.

[0083] Accordingly, the term "module" is understood to encompass a tangible entity, be that an entity that is physically constructed, specifically configured (e.g., hardwired), or temporarily (e.g., transitorily) configured (e.g., programmed) to operate in a specified manner or to perform part or all of any operation described herein. Considering examples in which modules are temporarily configured, each of the modules need not be instantiated at any one moment in time. For example, where the modules comprise a general-purpose hardware processor configured using software, the general-purpose hardware processor may be configured as respective different modules at different times. Software may accordingly configure a hardware processor, for example, to constitute a particular module at one instance of time and to constitute a different module at a different instance of time.

[0084] Communication device (e.g., UE) 900 may include a hardware processor 902 (e.g., a central processing unit (CPU), a graphics processing unit (GPU), a hardware processor core, or any combination thereof), a main memory 904 and a static memory 906, some or all of which may communicate with each other via an interlink (e.g., bus) 908. The communication device 900 may further include a display unit 910, an alphanumeric input device 912 (e.g., a keyboard), and a user interface (UI) navigation device 914 (e.g., a mouse). In an example, the display unit 910, input device 912 and UI navigation device 914 may be a touch screen display. The communication device 900 may additionally include a storage device (e.g., drive unit) 916, a signal generation device 918 (e.g., a speaker), a network interface device 920, and one or more sensors 921, such as a global positioning system (GPS) sensor, compass, accelerometer, or other sensor. The communication device 900 may include an output controller 928, such as a serial (e.g., universal serial bus (USB), parallel, or other wired or wireless (e.g., infrared (IR), near field communication (NFC), etc.) connection to communicate or control one or more peripheral devices (e.g., a printer, card reader, etc.),

[0085] The storage device 916 may include a communication device readable medium 922 on which is stored one or more sets of data structures or instructions 924 (e.g., software) embodying or utilized by any one or more of the techniques or functions described herein. The instructions 924 may also reside, completely or at least partially, within the main memory 904, within static memory 906, or within the hardware processor 902 during execution thereof by the communication device 900. In an example, one or any combination of the hardware processor 902, the main memory 904, the static memory 906, or the storage device 916 may constitute communication device readable media. [0086] While the communication device readable medium 922 is illustrated as a single medium, the term "communication device readable medium" may include a single medium or multiple media (e.g., a centralized or distributed database, and/or associated caches and servers) configured to store the one or more instructions 924.

[0087] The term "communication device readable medium" may include any medium that is capable of storing, encoding, or carrying instructions for execution by the communication device 900 and that cause the communication device 900 to perform any one or more of the techniques of the present disclosure, or that is capable of storing, encoding or carrying data structures used by or associated with such instructions. Non-limiting communication device readable medium examples may include solid-state memories, and optical and magnetic media. Specific examples of communication device readable media may include: non-volatile memory, such as semiconductor memory devices (e.g., Electrically Programmable Read-Only Memory (EPROM), Electrically Erasable Programmable Read-Only Memory (EEPROM)) and flash memory devices; magnetic disks, such as internal hard disks and removable disks; magneto-optical disks; Random Access Memory (RAM); and CD-ROM and DVD-ROM disks. In some examples, communication device readable media may include non- transitory communication device readable media. In some examples,

communication device readable media may include communication device readable media that is not a transitory propagating signal.

[0088] The instructions 924 may further be transmitted or received over a communications network 926 using a transmission medium via the network interface device 920 utilizing any one of a number of transfer protocols (e.g., frame relay, internet protocol (IP), transmission control protocol (TCP), user datagram protocol (UDP), hypertext transfer protocol (HTTP), etc.). Example communication networks may include a local area network (LAN), a wide area network (WAN), a packet data network (e.g., the Internet), mobile telephone networks (e.g., cellular networks), Plain Old Telephone (POTS) networks, and wireless data networks (e.g., Institute of Electrical and Electronics Engineers (IEEE) 802, 11 tamily of standards known as Wi-Fi®, IEEE 802. 16 family of standards known as WiMax®), IEEE 802.15.4 family of standards, a Long Term Evolution (LTE) family of standards, a Universal Mobile Telecommunications System (UMTS) family of standards, peer-to-peer (P2P) networks, among others. In an example, the network interface device 920 may include one or more physical jacks (e.g., Ethernet, coaxial, or phone jacks) or one or more antennas to connect to the communications network 926, In an example, the network interface device 920 may include a plurality of antennas to wireiessly communicate using at least one of single-input multiple-output (SIMO), MIMO, or multiple-input single-output (MI SO) techniques. In some examples, the network interface device 920 may wireiessly communicate using Multiple User MIMO techniques. The term "transmission medium" shall be taken to include any intangible medium that is capable of storing, encoding or carrying instructions for execution by the communication device 900, and includes digital or analog communications signals or other intangible medium to facilitate communication of such software. [0089] Additional notes and examples:

[0090] Example 1 is an apparatus of a user equipment (UE), the apparatus comprising: memory, and processing circuitry, the processing circuitry configured to: decode control information received on one or more channels of unlicensed spectrum, the control information including an indication that a grantless uplink (UL) transmission (GUL) is allowed without a prior UL grant; perform a listen-before-talk (LBT) procedure on the one or more channels of the unlicensed spectrum to determine if one of the channels is available; and upon determining the channel is available, encode UL control information and data for transmission using the grantless UL transmission, wherein the grantless uplink transmission is an unscheduled transmission, performed on the channel of the unlicensed spectrum without an UL grant.

[0091] In Example 2, the subject matter of Example 1 optionally includes wherein the control information is downlink control information (DCI) received on a common physical downlink control channel (cPDCCH) within the unlicensed spectrum.

[0092] In Example 3, the subject matter of any one or more of Examples

1-2 optionally include wherein the memory stores the UL control information and the data for transmission using the grantless UL transmission. [0093] In Example 4, the subject matter of any one or more of Examples

1-3 optionally include wherein the control information is radio resource control (RRC) information received on a physical downlink shared channel (PDSCH) within the unlicensed spectrum. [0094] In Example 5, the subject matter of any one or more of Examples

1-4 optionally include wherein the UL control information comprises at least one of the following: LIE identity (UEID) of the UE; a modulation coding scheme (MCS) used by the UE; a redundancy version (RV) used by the UE for the data transmission; a new data indicator (NOT) associated with the data transmission; a length of an UL burst communicating the UL control

information; and a maximum channel occupancy time (MCOT) reserved by the performed LBT.

[0095] In Example 6, the subject matter of any one or more of Examples

1-5 optionally include wherein the processing circuitn,' is configured to: encode a buffer status report (BSR) for transmission to an evolved Node-B (eNB), the BSR indicative of transmission congestion for scheduled UL transmissions by the UE.

[0096] In Example 7, the subject matter of Example 6 optionally includes wherein the control information including the indicator that the grantless UL transmission is allowed is received in response to the BSR.

[0097] In Example 8, the subject matter of any one or more of Examples

1-7 optionally include wherein the processing circuitry is configured to: monitor a common physical downlink control channel (cPDCCH) within the unlicensed spectrum for scheduled transmissions; and detect existence of a scheduled downlink (DL) transmission by an evolved Node-B (eNB) and/or burst information of a scheduled UL transmission in the unlicensed spectrum indicated by the cPDCCH.

[0098] In Example 9, the subject matter of Example 8 optionally includes wherein the processing circuitry is configured to: defer the grantless uplink transmission to avoid co-existence with the scheduled DL transmission and/or the scheduled UL transmission. [0099] In Example 10, the subject matter of any one or more of

Examples 1-9 optionally include wherein the processing circuitry is configured to: decode second downlink (DL) control information received on the one or more channels of the unlicensed spectrum, the second DL control information including an acknowledgement (ACK)/non-acknowledgement (NACK) signaling in response to the grantless uplink transmission.

[00100] In Example 11, the subject matter of any one or more of

Examples 9-10 optionally include wherein the second control information is received during a maximum channel occupancy time (MCOT) reserved by the UE during the LBT procedure.

[00101] In Example 12, the subject matter of any one or more of

Examples 1-1 1 optionally include wherein the processing circuitry is configured to: decode signaling indicating periodicity of a DRS transmission within a DTxW; and restrict the grantless UL transmission to a time interval outside of the DTxW.

[00 02] In Example 13, the subject matter of any one or more of

Examples 1-12 optionally include wherein the processing circuitry is configured to: decode an indication of available time domain resources that can be used for the grantless UL transmission. [00103] In Example 14, the subject matter of any one or more of

Examples 1-13 optionally include wherein the available time domain resources include a set of available subframes, and wherein the indication is a bitmap of N bits, with the pattern of the N bits repeating every N ms.

[00104] In Example 15, the subject matter of any one or more of

Examples 1-14 optionally include wherein the control information includes an indication of a maximum UL transmission duration and the processing circuitry is configured to: limit a duration of the grantless UL transmission to be within the maximum UL transmission duration.

[00105] Example 16 is an apparatus of an evolved Node-B (e B), the apparatus comprising: memory; and processing circuitry, the processing circuitry configured to: encode control information for transmission on one or more channels of unlicensed spectrum, the control information including an indication

3? that a grantless uplink (UL) transmission is allowed without a prior UL grant; decode UL control information and data received using the grantless UL transmission, wherein the grantless uplink transmission is an unscheduled transmission, performed on the one or more channels of the unlicensed spectrum; and encode either an acknowledgement (ACK) feedback or a non- acknowledgement (NACK) feedback in response to the grantless uplink transmission.

[00106] In Example 17, the subject matter of Example 16 optionally includes wherein the processing circuitry is configured to: encode an UL grant for transmission to the UE, the UL grant associated with a scheduled UL transmission; and detect a number of failures of the scheduled UL transmission.

[00107] In Example 18, the subject matter of any one or more of

Examples 16-17 optionally include wherein the memory stores the control information for transmission on the one or more channels of unlicensed spectrum.

[00108] In Example 19, the subject matter of any one or more of

Examples 17-18 optionally include wherein the processing circuitry is configured to: encode the control information indicating that the grantless UL transmission is allowed in response to the detected number of failures of the scheduled UL transmission,

[00109] In Example 20, the subject matter of any one or more of

Examples 16-19 optionally include wherein to encode the control information, the processing circuitry is configured to: encode downlink control information (DCI) including the indicator that the grantless UL transmission is allowed for transmission on a common physical downlink control channel (cPDCCH) within the unlicensed spectrum,

[00110] In Example 21, the subject matter of any one or more of

Examples 16-20 optionally include wherein to encode the control information, the processing circuitry is configured to: encode radio resource control (RRC) information including the indicator that the grantless UL transmission is allowed for transmission on a physical downlink shared channel (PDSCH) within the unlicensed spectrum. [00111] In Example 22, the subject matter of any one or more of

Examples 16-21 optionally include wherein the processing circuitry is configured to: decode a buffer status report (BSR) from a user equipment (UE), the BSR indicative of transmission congestion for scheduled UL transmissions by the UE.

[00112] In Example 23, the subject matter of Example 22 optionally includes wherein the processing circuitry is configured to: encode the control information with the indication that the grantless UL transmission is allowed for transmission on the one or more channels of the unlicensed spectrum in response to the BSR.

[00113] In Example 24, the subject matter of any one or more of

Examples 22-23 optionally include wherein the processing circuitry is configured to: decode a second grantless UL transmission, the second grantless UL transmission including a request for acknowledgement of the grantless UL transmission.

[00114] In Example 25, the subject matter of Example 24 optionally includes wherein the processing circuitry is configured to: encode a second acknowledgement (ACK)/non-acknowledgement (NACK) feedback in response to the grantless uplink transmission, in response to the second grantless UL transmission.

[00115] Example 26 is a computer-readable storage medium that stores instructions for execution by one or more processors of a user equipment (UE), the one or more processors to configure the UE to: decode an indication of a discovery reference signal (DRS) transmission window (DTxW) period indicating periodicity of a DRS transmission within the DTxW, decode control information received on one or more channels of unlicensed spectrum, the control information including an indication that a grantless uplink (UL) transmission is allowed without a prior UL grant: perform a iisten-before-taik (LBT) procedure on the one or more channels of the unlicensed spectrum, and transmit using the grantless UL transmission, encoded UL control information and data on a physical uplink shared channel (PUSCH), a short physical uplink control channel (sPUCCH) and/or an expended PUCCH (ePUCCH) of the unlicensed spectrum, wherein the grantiess uplink transmission is performed without an UL grant and within a time interval outside of the DTxW.

[00116] In Example 27, the subject matter of Example 26 optionally includes wherein the one or more processors further configure the UE to:

monitor a common physical downlink control channel (cPDCCH) within the unlicensed spectrum for scheduled transmissions; and detect existence of a scheduled downlink (DL) transmission by an evolved Node-B (eNB) and/or burst information of a scheduled UL transmission in the unlicensed spectrum, indicated by the cPDCCH. [00117] In Example 28, the subject matter of Example 27 optionally includes wherein the one or more processors further configure the UE to: defer the grantiess uplink transmission to avoid co-existence with the scheduled DL transmission or the scheduled UL transmission scheduled by an associated eNB.

[00118] In Example 29, the subject matter of any one or more of

Examples 27-28 optionally include wherein the one or more processors further configure the UE to: receive second control information on the one or more channels of the unlicensed spectrum, the second control information including acknowledgement (ACK)/non-acknowledgement (NACK) feedback in response to the grantiess uplink transmission. [00119] In Example 30, the subject matter of Example 29 optionally includes wherein the second control information is received during a maximum channel occupancy time (MCOT) reserved by the UE during the LBT procedure.

[00120] In Example 31, the subject matter of any one or more of

Examples 26-30 optionally include wherein the one or more processors further configure the UE to: detect failure to receive a first acknowledgement

(ACKVnon-acknowiedgement (NACK) signaling in response to the grantiess uplink transmission.

[00121] In Example 32, the subject matter of Example 31 optionally includes wherein the one or more processors further configure the UE to: in response to detecting the failure, encode a request for acknowledgement for the grantiess UL transmission; transmit the request for acknowledgement using a second grantiess UL transmission. [00122] In Example 33, the subject matter of Example 32 optionally includes wherein the processing circuitry is configured to: decode second acknowledgement (ACK)/non-acknowledgement (NACK) feedback associated with the grantiess uplink transmission, the second ACK/NACK signaling received in response to the second grantiess UL transmission.

[00123] Example 34 is an apparatus of a user equipment (UE), the apparatus comprising: means for decoding an indication of a discovery reference signal (DRS) transmission window (DTxW) period indicating periodicity of a DRS transmission within the DTxW; means for decoding control information received on one or more channels of unlicensed spectrum, the control information including an indication that a grantiess uplink (UL) transmission is allowed without a prior UL grant; means for performing a listen-before-talk (LBT) procedure on the one or more channels of the unlicensed spectrum; and means for transmitting using the grantiess UL transmission, encoded UL control information and data on a physical uplink shared channel (PUSCH), a short physical uplink control channel (sPUCCH) and/or an expended PUCCH

(ePUCCH) of the unlicensed spectrum, wherein the grantiess uplink

transmission is performed without an UL grant and within a time interval outside of the DTxW. [00124] In Example 35, the subject matter of Example 34 optionally includes means for monitoring a common physical downlink control channel (cPDCCH) within the unlicensed spectrum for scheduled transmissions; and means for detecting existence of a scheduled downlink (DL) transmission by an evolved Node-B (eNB) and/or burst information of a scheduled UL transmission in the unlicensed spectrum, indicated by the cPDCCH.

[00125] In Example 36, the subject matter of Example 35 optionally includes means for deferring the grantiess uplink transmission to avoid coexistence with the scheduled DL transmission or the scheduled UL transmission scheduled by an associated eNB. [00126] In Example 37, the subject matter of any one or more of

Examples 35-36 optionally include means for receiving second control information on the one or more channels of the unlicensed spectmm, the second control information including acknowledgement (ACK)/non-acknowledgement (NACK) feedback in response to the grantless uplink transmission.

[00127] In Example 38, the subject matter of Example 37 optionally includes wherein the second control information is received during a maximum channel occupancy time (MCOT) reserved by the LIE during the LBT procedure,

[00128] In Example 39, the subject matter of any one or more of

Examples 34-38 optionally include means for detecting failure to receive a first acknowledgement (ACK)/non-acknowledgement (NACK) signaling in response to the grantless uplink transmission. [00129] In Example 40, the subject matter of Example 39 optionally includes means for encoding a request for acknowledgement for the grantless UL transmission, in response to detecting the failure; means for transmitting the request for acknowledgement using a second grantless UL transmission.

[00130] In Example 41, the subject matter of Example 40 optionally includes means for decoding second acknowledgement (ACK)/non- acknowledgement (NACK) feedback associated with the grantless uplink transmission, the second ACK/NACK signaling received in response to the second grantless UL transmission.

[00131] Publications, patents, and patent documents referred to in this document are incorporated by reference herein in their entirety, as though individually incorporated by reference. In the event of inconsistent usages between this document and those documents so incorporated by reference, the usage in the incorporated reference(s) are supplementary to that of this document; for irreconcilable inconsistencies, the usage in this document controls.

[00132] The above description is intended to be illustrative, and not restrictive. For example, the above-described examples (or one or more aspects thereof) may be used in combination with others. Other embodiments may be used, such as by one of ordinary skill in the art upon reviewing the above description. The Abstract is to 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. Also, in the above Detailed Description, various features may be grouped together to streamline the disclosure. However, the claims may not set forth every feature disclosed herein as embodiments may feature a subset of said features. Further, embodiments may include fewer features than those disclosed in a particular example. Thus, the following claims are hereby incorporated into the Detailed Description, with a claim standing on its own as a separate embodiment. The scope of the embodiments disclosed herein is to be determined with reference to the appended claims, along with the full scope of equivalents to which such claims are entitled.

Claims

is claimed is:

An apparatus of a user equipment (UE), the apparatus comprising:

memory; and processing circuitry, the processing circuitry configured to: decode control information received on one or more channels of unlicensed spectnmi, the control information including an indication that a grantless uplink (UL) transmission (GUL) is allowed without a prior UL grant;

perform a listen-before-talk (LBT) procedure on the one or more channels of the unlicensed spectrum to determine if one of the channels is available; and

upon determining the channel is available, encode UL control information and data for transmission using the grantless UL

transmission, wherein the grantless uplink transmission is an

unscheduled transmission, performed on the channel of the unlicensed spectrum without an UL grant.

2. The apparatus of claim 1, wherein the control information is downlink control information (DCI) received on a common physical downlink control channel (cPDCCH) within the unlicensed spectrum.

3. The apparatus of any of claims 1-2, wherein the memory stores the UL control information and the data for transmission using the grantless UL transmission.

4. The apparatus of any of claims 1-2, wherein the control information is radio resource control (RRC) information received on a physical downlink shared channel (PDSCH) within the unlicensed spectrum.

5. The apparatus of claim 1, wherein the UL control information comprises at least one of the fo llowing:

UE identity (UEiD) of the UE;

a modulation coding scheme (MCS) used by the UE;

a redundancy version (RV) used by the UE for the data transmission; a new data indicator (NDI) associated with the data transmission;

a length of an UL burst communicating the UL control information, and a maximum channel occupancy time (MCOT) reserved by the performed

LBT.

6. The apparatus of claim 1, wherein the processing circuitry is configured to:

encode a buffer status report (BSR) for transmission to an evolved Node- B (eNB), the BSR indicative of transmission congestion for scheduled UL transmissions by the UE.

7. The apparatus of claim 6, wherein the control information including the indicator that the grantless UL transmission is allowed is received in response to the BSR.

8. The apparatus of any of claims 1 or 7, wherein the processing circuitry is configured to:

monitor a common physical downlink control channel (cPDCCH) within the unlicensed spectrum for scheduled transmissions: and

detect existence of a scheduled downlink (DL) transmission by an evolved Node-B (eNB) and/or burst information of a scheduled UL transmission in the unlicensed spectrum indicated by the cPDCCH.

9. The apparatus of claim 8, wherein the processing circuitry is configured to:

defer the grantless uplink transmission to avoid co-existence with the scheduled DL transmission and/or the scheduled UL transmission.

10. The apparatus of any of claims 1 or 2, wherein the processing circuitry is configured to:

decode second downlink (DL) control information received on the one or more channels of the unlicensed spectmm, the second DL control information including an acknowledgement (ACK)/non-acknowledgement (NACK) signaling in response to the grantless uplink transmission.

11 , The apparatus of claim 9, wherein the second control information is received during a maximum channel occupancy time (MCOT) reserved by the UE during the LBT procedure.

12. The apparatus of claim 1, wherein the processing circuitry is configured to:

decode signaling indicating periodicity of a DRS transmission within a DTxW; and

restrict the grantless UL transmission to a time interval outside of the

DTxW.

13. The apparatus of any of claims 1 or 12, wherein the processing circuitry is configured to:

decode an indication of available time domain resources that can be used for the grantless UL transmission.

14. The apparatus of any of claims 1 or 12, wherein the available time domain resources include a set of available subframes, and wherein the indication is a bitmap of N bits, with the pattern of the N bits repeating every N ms. 5. The apparatus of claim I, wherein the control information includes an indication of a maximum UL transmission duration and the processing circuitry is configured to:

limit a duration of the grantless UL transmission to be within the maximum UL transmission duration.

16, An apparatus of an evolved Node-B (eNB), the apparatus comprising: memory; and processing circuitry, the processing circuitry configured to: encode control information for transmission on one or more channels of unlicensed spectrum, the control information including an indication that a grantless uplink (UL) transmission is allowed without a prior UL grant; decode UL control information and data received using the grantless UL transmission, wherein the grantless uplink transmission is an unscheduled transmission, performed on the one or more channels of the unlicensed spectrum; and

encode either an acknowledgement (ACK) feedback or a non- acknowledgement (NACK) feedback in response to the grantless uplink transmission.

17. The apparatus of claim 16, wherein the processing circuitry is configured to:

encode an UL grant for transmission to the UE, the UL grant associated with a scheduled UL transmission; and

detect a number of failures of the scheduled UL transmission.

18. The apparatus of claim 16, wherein the memory stores the control information for transmission on the one or more channels of unlicensed spectrum.

The apparatus of claim 17, wherein the processing circuitry is configured to:

encode the control information indicating that the grantless UL transmission is allowed in response to the detected number of failures of the scheduled UL transmission.

20, The apparatus of any of claims 16-19, wherein to encode the control information, the processing circuitry is configured to:

encode downlink control information (DCI) including the indicator that the grantless UL transmission is allowed for transmission on a common physical downlink control channel (cPDCCH) within the unlicensed spectrum.

21 . The apparatus of claim 6, wherein to encode the control information, the processing circuitry is configured to: encode radio resource control (RRC) information including the indicator that the grantless UL transmission is allowed for transmission on a physical downlink shared channel (PDSCH) within the unlicensed spectrum.

22, The apparatus of any of claims 16 or 21 , wherein the processing circuitry is configured to:

decode a buffer status report (BSR) from a user equipment (UE), the BSR indicative of transmission congestion for scheduled UL transmissions by the UE.

23 , A computer-readable storage medium that stores instructions for execution by one or more processors of a user equipment (UE), the one or more processors to configure the UE to:

decode an indication of a discovery reference signal (DRS) transmission window (DTxW) period indicating periodi city of a DRS transmission within the DTxW;

decode control information received on one or more channels of unlicensed spectrum, the control information including an indication that a grantless uplink (UL) transmission is allowed without a prior UL grant;

perform a listen-before-talk (LBT) procedure on the one or more channels of the unlicensed spectrum; and

transmit using the grantless UL transmission, encoded UL control information and data on a physical uplink shared channel (PUSCH), a short physical uplink control channel (sPUCCH) and/or an expended PUCCH

(ePUCCH) of the unlicensed spectrum, wherein the grantless uplink

transmission is performed without an UL grant and within a time interval outside of the DTxW.

24, The computer-readable storage medium of claim 23, wherein the one or more processors further configure the UE to:

monitor a common physical downlink control channel (cPDCCH) within the unlicensed spectrum for scheduled transmissions; and detect existence of a scheduled downlink (DL) transmission by an evolved Node-B (eNB) and/or burst information of a scheduled UL transmission in the unlicensed spectrum, indicated by the cPDCCH.

25. The computer-readable storage medium of claim 24, wherein the one or more processors further configure the UE to:

defer the grantless uplink transmission to avoid co-existence with the scheduled DL transmission or the scheduled UL transmission scheduled by an associated eNB.

26. The computer-readable storage medium of any of claims 24-25, wherein the one or more processors further configure the UE to:

receive second control information on the one or more channels of the unlicensed spectrum, the second control information including

acknowledgement (ACK)/non-acknowledgement (NACK) feedback in response to the grantless uplink transmission,

27. The computer-readable storage medium of claim 26, wherein the second control information is received during a maximum channel occupancy time (MCOT) reserved by the UE during the LBT procedure.