HK1262504B - Apparatuses for co-existence of grantless uplink and scheduled transmissions - Google Patents

Description

Apparatus for coexistence of unlicensed uplink and scheduled transmissions

Priority Declaration

This application claims priority to U.S. Provisional Patent Application No. 62/311,698, filed on March 22, 2016, entitled “ENABLING CO-EXISTENCE OF AUTONOMOUS UPLINK TRANSMISSION WITH SCHEDULED TRANSMISSION AT ENB,” which is incorporated herein by reference in its entirety.

Technical Field

Embodiments relate to wireless communications. Some embodiments relate to wireless networks, including 3GPP (3rd Generation Partnership Project) networks, 3GPP LTE (Long Term Evolution) networks, 3GPP 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 unlicensed (or autonomous) uplink transmissions (GUL) of user equipment (UE). Some embodiments relate to enabling coexistence of unlicensed (or autonomous) uplink transmissions with scheduled transmissions.

Background Art

As the number of different types of devices communicating with various network devices increases, so too is the use of 3GPP LTE systems. The penetration of mobile devices (user equipment, or UE) in modern society continues to drive demand for a wide variety of connected devices in many different environments. The use of connected UEs using 3GPP LTE systems is increasing in all areas of home and work life. Fifth-generation (5G) wireless systems are imminent and are expected to achieve even higher speeds, connectivity, and availability.

LTE and LTE-Advanced are standards for wireless communication of high-speed data for user equipment (UE) such as mobile phones. In LTE-Advanced and various wireless systems, carrier aggregation is a technique in which multiple carrier signals operating at different frequencies can be used to carry communications for a single UE, thereby increasing the bandwidth available to a single device. In some embodiments, carrier aggregation can be used when one or more component carriers operate on unlicensed frequencies.

The explosive growth of wireless traffic has led to the need to increase rates. With mature physical layer technologies, further improvements in spectrum efficiency will be negligible. On the other hand, the lack of licensed spectrum in low frequency bands has led to a lack of data rate improvements. As a result, there has been interest in the operation of LTE systems in unlicensed spectrum. Therefore, important improvements to LTE in 3GPP Release 13 have allowed its operation in unlicensed spectrum via Licensed Assisted Access (LAA), which expands the system bandwidth by leveraging the flexible carrier aggregation (CA) framework introduced by the LTE-Advanced system. The Rel-13 LAA system focuses on the design of DL operations on unlicensed spectrum via CA, while the Rel-14 improved LAA (eLAA) system focuses on the design of UL operations on unlicensed spectrum via CA. More improved operations of LTE systems in unlicensed spectrum are expected in future releases and 5G systems. Possible LTE operations in unlicensed spectrum include (but are not limited to) LTE operation in unlicensed spectrum via dual connectivity (DC), or LAA based on DC and a separate LTE system in unlicensed spectrum, where the LTE-based technology operates only in the unlicensed spectrum without the need for an "anchor" in the licensed spectrum. This technology is called MulteFire. MulteFire combines the performance advantages of LTE technology with the simplicity of Wi-Fi-like deployment and is considered a very important technology component to meet the ever-increasing wireless traffic.

BRIEF DESCRIPTION OF THE DRAWINGS

In the accompanying drawings, which are not necessarily drawn to scale, like reference numerals may represent similar components in different views. Like reference numerals with different letter suffixes may represent different instances of detailed components. In the following figures in the accompanying drawings, some embodiments are shown by way of example and not limitation.

As used herein, the terms "autonomous uplink transmission" and "unlicensed uplink transmission" are interchangeable.

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 communication network according to some embodiments described herein.

FIG2 is a block diagram of a user equipment (UE) according to some embodiments.

3 is a block diagram of an evolved Node B (eNB) in accordance with some embodiments.

FIG4 illustrates an unlicensed uplink transmission (GUL) according to an example embodiment.

5 illustrates an example ungranted UL transmission (GUL) within a restricted timing window according to an example embodiment.

6A and 6B illustrate example downlink (DL) transmissions following an ungranted UL transmission according to example embodiments.

6C illustrates an example downlink (DL) transmission following an ungranted UL transmission requesting an acknowledgment, according to an example embodiment.

7 and 8 are flow diagrams illustrating example functionality for implementing unlicensed uplink transmissions in accordance with some embodiments.

FIG9 shows a block diagram of a communication device such as an eNB or a UE according to some embodiments.

DETAILED DESCRIPTION

Embodiments relate to systems, devices, apparatus, assemblies, methods, and computer-readable media for improving wireless communications, and more particularly to communication systems that operate in conjunction with carrier aggregation, License Assisted Access (LAA), improved LAA (eLAA), and MulteFire communications. The following description and accompanying drawings illustrate specific embodiments that enable those skilled in the art to implement. Other embodiments may include structural, logical, electrical, processing, and other changes. Portions and features of some embodiments may be included in or substituted for those of other embodiments, and all available equivalents of the described elements are intended to be encompassed.

FIG1 is a block diagram of a system including an evolved Node B (eNB) and a user equipment (UE) that can operate in a wireless communication 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. The UE 104 and the eNB 120 communicate using a system that supports carrier aggregation (CA) and uses unlicensed frequency bands so that the air interface 190 supports multiple frequency carriers and licensed and unlicensed frequency bands. Component carrier 180 and component carrier 185 are shown in FIG1. Although two component carriers are shown, various embodiments may include any number of two or more component carriers. Various embodiments may operate using any number of licensed channels and any number of unlicensed channels.

In addition, in various embodiments described herein, at least one of the component carriers 180, 185 in the air interface 190 includes a carrier operating on an unlicensed frequency, referred to herein as an unlicensed carrier. An "unlicensed carrier" or "unlicensed frequency" refers to a range of radio spectrum that has not been specifically reserved for use by a system. For example, some frequency ranges may be used by communication systems operating under different communication standards, such as frequency bands used by both the Institute of Electrical and Electronics Engineers (IEEE) 802.11 standard (e.g., "WiFi") and the Third Generation Partnership Project (3GPP) standard (including LTE and LTE Advanced and enhancements to LTE (as discussed below)). In contrast, a "licensed channel" or "licensed spectrum" operates under a particular standard with limited concern for the presence of other, undesirable signals operating under a different standard.

Communications on an LTE network can be divided into 10ms frames, each containing ten 1ms subframes. Each subframe can in turn contain two 0.5ms time slots. Depending on the system used, each time slot can contain 6-7 symbols. A resource block (RB) (also referred to as a physical resource block (PRB)) can be the smallest unit of resources that can be allocated to a UE. A resource block can be 180kHz wide in frequency and 1 time slot long in time. In frequency, a resource block can be 12 15kHz subcarriers or 24 7.5kHz subcarriers wide. For most channels and signals, 12 subcarriers can be used per resource block. In frequency division duplex (FDD) mode, uplink and downlink frames can both be 10ms and can be separated in frequency (full duplex) or time (half duplex). In time division duplex (TDD) mode, uplink and downlink subframes can be transmitted on the same frequency and can be multiplexed in the time domain. A downlink resource grid can be used for downlink transmission from an eNB to a UE. The resource grid can be a time-frequency resource grid, which is a physical resource in the downlink in each time slot. Each column and each row of the resource grid can correspond to an OFDM symbol and an OFDM subcarrier, respectively. The duration of the resource grid in the time domain can correspond to a time slot. The smallest time-frequency unit in the resource grid can be represented by a resource element. Each resource grid can include multiple resource blocks as described above, which describe the mapping of specific physical channels to resource elements. Each resource block can include 12 (subcarriers) * 14 (symbols) = 168 resource elements.

In some embodiments, a downlink resource grid can be used for downlink transmissions from eNB 120 to UE 104, while uplink transmissions from UE 104 to eNB 120 can utilize similar techniques. A resource grid can be a time-frequency resource grid, also known as a resource grid or time-frequency resource grid, representing the physical resources in each downlink transmission within each time slot. This representation of the time-frequency plane is commonly used in OFDM systems, making it intuitive for radio resource allocation. Each column and row of the resource grid can correspond to an OFDM symbol and an OFDM subcarrier, respectively. The duration of the resource grid in the time domain can correspond to a time slot in a radio frame. The smallest time-frequency unit in the resource grid can be represented by a resource element (RE). Each resource grid includes multiple resource blocks (RBs), which describe the mapping of specific physical channels to resource elements. Each resource block includes a collection of resource elements in the frequency domain and can represent the minimum amount of resources currently available for allocation. There are several different physical downlink channels that are transmitted using such resource blocks. Two example physical downlink channels are the physical downlink shared channel and the physical downlink control channel.

There may be several different physical downlink channels transmitted using such resource blocks. Two of these physical downlink channels may be the Physical Downlink Control Channel (PDCCH) and the Physical Downlink Shared Channel (PDSCH). Each subframe may be divided into the PDCCH and the PDSCH.

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, among other things, the transport format and resource allocation associated with the PDSCH channel. It also informs the UE 104 about the transport format, resource allocation, and hybrid automatic repeat request (HARQ) information associated with the uplink shared channel. Typically, downlink scheduling (e.g., allocating control and shared channel resources to UEs 104 within a cell) can be performed at the eNB 120 based on channel quality information fed back from the UE 104 to the eNB 120, and downlink resource allocation information can then be sent to the UE 104 on a control channel (PDCCH) intended for (allocated to) the UE 104.

PDCCH uses CCE (control channel elements) to transmit control information. Before being mapped to resource elements, PDCCH complex symbols are first organized into four groups and then sequenced using a sub-block interleaver for rate matching. Each PDCCH is sent using one or more of these control channel elements (CCEs), where each CCE corresponds to nine groups of four physical resource elements called resource element groups (REGs). Four QPSK symbols are mapped to each REG. Depending on the size of the downlink control information (DCI) and the channel conditions, the PDCCH can be sent using one or more CCEs. Four or more different PDCCH formats with different numbers of CCEs can be defined in LTE (e.g., aggregation levels, L=1, 2, 4, or 8).

The embodiments described herein may fall within the scope of a single system in the unlicensed spectrum, including but not limited to MulteFire (MF), the next version of the LAA system that allows UL operation (e.g., eLAA), 5G unlicensed systems, and DC-based LAA systems. The unlicensed band of current interest in 3GPP is the 5 GHz band, which has a wide spectrum that is commonly used worldwide. The 5 GHz band in the United States is governed by the Unlicensed National Information Infrastructure (UNII) rules of the Federal Communications Commission (FCC). The main existing systems in the 5 GHz band are wireless local area networks (WLANs), especially communication networks based on IEEE802.11a/n/ac technologies. Since WLAN systems are widely deployed by individuals and operators for carrier-level access services and data offloading, Listen-Before-Talk (LBT) is considered a mandatory feature of Rel-13 LAA and Rel-14eLAA systems to achieve good coexistence with existing systems.

LBT is a process in which a radio transmitter first senses the medium and transmits only when the medium is sensed to be idle. In an example, a scheduling-based UL LAA design may include UL PUSCH transmission based on explicit UL grant transmission via PDCCH (e.g., via DCI format 0A/0B). After the LBT process is completed at the eNB, UL grant transmission is performed on the component carrier where PUSCH transmission is expected. After receiving the UL grant, the scheduled UE is expected to perform short-term LBT or Type 4 (Cat 4) LBT during the allocated time interval. If LBT is successful at the scheduled UE, the UE may transmit PUSCH on the resources indicated by the UL grant.

However, because LBT is required both on the eNB side (e.g., when sending an UL grant) and on the scheduled UE side (e.g., before the UE transmits), UL performance in unlicensed spectrum (e.g., during MulteFire operation solely in unlicensed spectrum) can be significantly poor. This degradation in performance can typically occur in scenarios where scheduled systems (e.g., LTE-based systems) coexist with unscheduled autonomous systems (i.e., Wi-Fi). In some instances, LTE-based systems may also use a 4-subframe processing delay, whereby the first four subframes in a transmission burst cannot be configured for UL because an UL grant is not available for those subframes within the same transmission burst. The 4-subframe delay requirement may also result in processing delays for LTE systems operating in unlicensed spectrum.

In an example embodiment, to improve communication system performance in unlicensed spectrum (e.g., due to LBT requirements on both sides and a 4-subframe processing delay), a UE can perform grantless UL transmissions without the eNB sending an UL grant for the UE to perform PUSCH transmissions. As a result, the requirement for LBT on both sides can be reduced when a UE's unlicensed UL transmission occurs, as the eNB will not perform LBT and LBT can be performed solely by the UE. Since a UE performing unlicensed UL transmissions does not need to wait for a UL grant from the eNB, the additional 4-subframe delay required to access the channel for UL transmission is eliminated, further facilitating performance improvements.

The coexistence embodiments described herein can operate within a wireless network system 100. In the wireless network system 100, UE 104 and any other UEs in the system can be, for example, laptops, smartphones, tablets, printers, machine-type devices such as smart meters or specialized equipment for health monitoring, remote security monitoring systems, intelligent transportation systems, or any other wireless devices with or without a user interface. An eNB 120 provides network connectivity for UE 104 to a larger network (not shown). Connectivity for UE 104 is provided via an air interface 190 within the eNB service area provided by the eNB 120. In some embodiments, such a larger network can be a wide area network operated by a cellular network provider or the Internet. Each eNB service area associated with an eNB 120 is supported by an antenna integrated with the eNB 120. The service area can be divided into multiple sectors associated with specific antennas. These sectors can be physically associated with fixed antennas or can be allocated to physical areas. Tunable antennas or antenna settings can be adjusted in a beamforming process used to direct signals to specific sectors. For example, one embodiment of the eNB 120 includes three sectors, each sector covering a 120 degree area with antenna arrays pointed toward each sector to provide 360 degree coverage around the eNB 120 .

UE 104 includes a control circuit 105 coupled to a transmit circuit 110 and a receive circuit 115. The transmit circuit 110 and the receive circuit 115 may each be coupled to one or more antennas. The control circuit 105 may be adapted to perform operations associated with wireless communication using carrier aggregation. The transmit circuit 110 and the receive circuit 115 may be adapted to transmit and receive data, respectively. The control circuit 105 may be adapted or configured to perform various operations such as those described elsewhere in this disclosure in connection with the UE. The transmit circuit 110 may transmit multiple multiplexed uplink physical channels. The multiple uplink physical channels may be multiplexed based on time division multiplexing (TDM) or frequency division multiplexing (FDM) as well as carrier aggregation. The transmit circuit 110 may be configured to receive block data from the control circuit 105 for transmission over the air interface 190. Similarly, the receive circuit 115 may receive multiple multiplexed downlink physical channels from the air interface 190 and relay the physical channels to the control circuit 105. Uplink physical channels and downlink physical channels may be multiplexed according to FDM. Transmitting circuitry 110 and receiving circuitry 115 may transmit and receive control data and content data (eg, messages, images, videos, etc.) structured within data blocks conveyed by physical channels.

1 also illustrates an eNB 120 according to various embodiments. The eNB 120 circuitry may include control circuitry 155 coupled to transmit circuitry 160 and receive circuitry 165. The transmit circuitry 160 and receive circuitry 165 may each be coupled to one or more antennas that may be used to enable communication over an air interface 190.

Control circuitry 155 may be adapted to perform operations for managing channels and component carriers used in conjunction with various UEs. Transmit circuitry 160 and receive circuitry 165 may be adapted to transmit data to and receive data from any UE connected to eNB 120, respectively. Transmit circuitry 160 may transmit a downlink physical channel comprising a plurality of downlink subframes. Receive circuitry 165 may receive a plurality of uplink physical channels from various UEs, including UE 104. The plurality of uplink physical channels may be multiplexed according to FDM and using carrier aggregation.

As described above, communications over the air interface 190 may utilize carrier aggregation, wherein multiple different component carriers 180, 185 may 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. A radio resource control (RRC) connection may be handled by only one of the component carrier elements, which may be referred to as the primary component carrier, with the other component carriers being referred to as secondary component carriers. In some embodiments, the primary component carrier is provided by a primary cell (PCell) and may operate in a licensed frequency band to provide efficient, conflict-free communication. This primary channel may be used to schedule other channels, including unlicensed channels. In this regard, the PCell is the primary cell with which the UE 104 communicates and maintains its connection to the network.

In an example, one or more secondary cells (SCells) may also be activated and allocated to UEs that support carrier aggregation using licensed and unlicensed bands (e.g., UL and DL communications based on eLAA).

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

In some embodiments, the wireless communication network 100 may include the capability to support communication between the eNodeB 120 and the UE 104 only via unlicensed spectrum (e.g., MulteFire communication). In addition, the UE may be configured to perform unlicensed uplink transmissions, as will be described in more detail with reference to FIGs. 4-9.

As used herein, the term circuitry may refer to, include, or be a part of an application specific integrated circuit (ASIC), an electronic circuit, a processor (shared, dedicated, or group), or a 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, a circuit may be implemented in one or more software or firmware modules, or the functionality associated with the circuit may be implemented by one or more software or firmware modules. In some embodiments, a circuit may include logic that is at least partially operable with hardware. The embodiments described herein may be implemented into a system using any appropriately configured hardware or software.

FIG2 is a functional diagram of a user equipment (UE) according to some embodiments. UE 200 may be suitable for use as UE 104 shown in FIG1 . In some embodiments, UE 200 may include at least application circuitry 202, baseband circuitry 204, radio frequency (RF) circuitry 206, front-end module (FEM) circuitry 208, and one or more antennas 210A-210D, coupled together as shown. In some embodiments, other circuits or arrangements may include one or more elements or components of application circuitry 202, baseband circuitry 204, RF circuitry 206, or FEM circuitry 208, and in some cases may also include other elements or components. As an example, "processing circuitry" may include one or more elements or components, some or all of which may be included in application circuitry 202 or 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 RF circuitry 206 or FEM circuitry 208. However, these examples are not limiting, as in some cases, the processing circuitry or transceiver circuitry may also include other elements or components.

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 specialized processors (e.g., graphics processors, application processors, etc.). The processor(s) may be coupled to or include a memory/storage device and may be configured to execute instructions stored in the memory/storage device to enable various applications and/or operating systems to run on the system to implement one or more of the functions described herein.

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 the receive signal path of the RF circuitry 206 and generate baseband signals for the transmit signal path of the RF circuitry 206. The baseband processing circuitry 204 may interface with the application circuitry 202 to generate and process baseband signals and control the operation of the RF circuitry 206. For example, in some embodiments, the baseband circuitry 204 may include a second generation (2G) baseband processor 204a, a third generation (3G) baseband processor 204b, a fourth generation (4G) baseband processor 204c, or one or more other baseband processors 204d for other existing, developing, or future generations (e.g., fifth generation (5G), 6G, etc.). The baseband circuitry 204 (e.g., one or more of the baseband processors 204a-204d) may handle various radio control functions that support communication with one or more radio networks via the RF circuitry 206. Radio control functions may include, but are not limited to, signal modulation/demodulation, encoding/decoding, radio frequency shifting, and the like. In some embodiments, the modulation/demodulation circuitry of baseband circuitry 204 may include FFT, precoding, or constellation mapping/demapping functions. In some embodiments, the encoding/decoding circuitry of baseband circuitry 204 may include low-density parity check (LDPC) encoder/decoder functions, and optionally other technologies such as block codes, convolutional codes, turbo codes, and the like, which may be used to support legacy protocols. The embodiments of the modulation/demodulation and encoder/decoder functions are not limited to these examples, and other suitable functions may be included in other embodiments.

In some embodiments, the baseband circuitry 204 may include elements of a protocol stack, such as elements of the Evolved Universal Terrestrial Radio Access Network (E-UTRAN) protocol, including, for example, physical (PHY), medium access control (MAC), radio link control (RLC), packet data convergence protocol (PDCP), or radio resource control (RRC) elements. The central processing unit (CPU) 204e of the baseband circuitry 204 may be configured to execute signaling elements of the protocol stack for the PHY, MAC, RLC, PDCP, and/or RRC layers. In some embodiments, the baseband circuitry may include one or more audio digital signal processors (DSPs) 204f. The one or more audio DSPs 204f may include elements for compression/decompression and echo cancellation, and in other embodiments may include other suitable processing elements. In some embodiments, the components of the baseband circuitry may be appropriately combined in a single chip, a single chipset, or arranged on the same circuit board. In some embodiments, some or all of the components of the baseband circuitry 204 and the application circuitry 202 may be implemented together, for example, on a system on a chip (SOC).

In some embodiments, baseband circuitry 204 can provide communications compatible with one or more radio technologies. For example, in some embodiments, baseband circuitry 204 can support communications with an Evolved Universal Terrestrial Radio Access Network (EUTRAN) or other wireless metropolitan area network (WMAN), wireless local area network (WLAN), or wireless personal area network (WPAN). Embodiments in which baseband circuitry 204 is configured to support radio communications of multiple wireless protocols may be referred to as multimode baseband circuitry.

RF circuitry 206 may support communication with a wireless network using modulated electromagnetic radiation over a non-solid medium. In various embodiments, RF circuitry 206 may include switches, filters, amplifiers, and the like to facilitate communication with the wireless network. RF circuitry 206 may include a receive signal path that may include circuitry for down-converting RF signals received from FEM circuitry 208 and providing a baseband signal to baseband circuitry 204. RF circuitry 206 may also include a transmit signal path that may include circuitry for up-converting baseband signals provided by baseband circuitry 204 and providing an RF output signal to FEM circuitry 208 for transmission.

In some embodiments, RF circuitry 206 may include a receive signal path and a transmit signal path. The receive signal path of RF circuitry 206 may include mixer circuitry 206a, amplifier circuitry 206b, and filter circuitry 206c. The transmit signal path of RF circuitry 206 may include filter circuitry 206c and mixer circuitry 206a. RF circuitry 206 may also include synthesizer circuitry 206d for synthesizing frequencies for use by mixer circuitry 206a in the receive and transmit signal paths. In some embodiments, mixer circuitry 206a in the receive signal path may be configured to downconvert the RF signal received from FEM circuitry 208 based on the synthesized frequency provided by synthesizer circuitry 206d. Amplifier circuitry 206b may be configured to amplify the downconverted signal, and filter circuitry 206c may be a low-pass filter (LPF) or a band-pass filter (BPF) configured to remove unwanted signals from the downconverted signal to generate an output baseband signal. The output baseband signal may be provided to baseband circuitry 204 for further processing. In some embodiments, the output baseband signal can be a zero-frequency baseband signal, but this is not required. In some embodiments, the mixer circuit 206a of the receive signal path can include a passive mixer, but the scope of the embodiments is not limited in this respect. In some embodiments, the mixer circuit 206a of the transmit signal path can be configured to up-convert the input baseband signal based on the synthesized frequency provided by the synthesizer circuit 206d to generate an RF output signal for the FEM circuit 208. The baseband signal can be provided by the baseband circuit 204 and can be filtered by the filter circuit 206c. The filter circuit 206c can include a low-pass filter (LPF), but the scope of the embodiments is not limited in this respect.

In some embodiments, the mixer circuit 206a of the receive signal path and the mixer circuit 206a of the transmit signal path may include two or more mixers and may be arranged to be used for orthogonal down-conversion and/or up-conversion, respectively. In some embodiments, the mixer circuit 206a of the receive signal path and the mixer circuit 206a of the transmit signal path may include two or more mixers and may be arranged to be used for image rejection (e.g., Hartley image rejection). In some embodiments, the mixer circuit 206a of the receive signal path and the mixer circuit 206a of the transmit signal path may be arranged to be used for direct down-conversion and/or direct up-conversion, respectively. In some embodiments, the mixer circuit 206a of the receive signal path and the mixer circuit 206a of the transmit signal path may be configured for superheterodyne operation.

In some embodiments, the output baseband signal and the input baseband signal may be analog baseband signals, but the scope of the embodiments is not limited in this respect. In some alternative embodiments, the output baseband signal and the input baseband signal may be digital baseband signals. In these alternative embodiments, the RF circuitry 206 may include analog-to-digital converter (ADC) and digital-to-analog converter (DAC) circuitry, and the baseband circuitry 204 may include a digital baseband interface to communicate with the RF circuitry 206. In some dual-mode embodiments, separate radio IC circuitry may be provided to process signals for each spectrum, but the scope of the embodiments is not limited in this respect.

In some embodiments, synthesizer circuit 206d can be a fractional N synthesizer or a fractional N/N+1 synthesizer, but the scope of the embodiment is not limited in this respect, because other types of frequency synthesizers may be suitable. For example, synthesizer circuit 206d can be a delta-sigma synthesizer, a frequency multiplier, or a synthesizer including a phase-locked loop with a frequency divider. Synthesizer circuit 206d can be configured to synthesize the output frequency used by mixer circuit 206a for RF circuit 206 based on the frequency input and the frequency divider control input. In some embodiments, synthesizer circuit 206d can be a fractional N/N+1 synthesizer. In some embodiments, the frequency input can be provided by a voltage-controlled oscillator (VCO), but this is not required. The frequency divider control input can be provided by baseband circuit 204 or application processor 202 according to the required output frequency. In some embodiments, the frequency divider control input (e.g., N) can be determined from a lookup table based on the channel indicated by application processor 202.

The synthesizer circuit 206d of the RF circuit 206 may include a frequency divider, a delay-locked loop (DLL), a multiplexer, and a phase accumulator. In some embodiments, the frequency divider may be a dual-modulus frequency divider (DMD), and the phase accumulator may be a digital phase accumulator (DPA). In some embodiments, the DMD may be configured to divide the input signal by N or N+1 (e.g., based on a carry out) to provide a fractional division ratio. In some example embodiments, the DLL may include a set of cascaded tunable delay elements, a phase detector, a charge pump, and a D-type flip-flop. In these embodiments, the delay elements may be configured to decompose the VCO cycle into a maximum of Nd equal phase groups, 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.

In some embodiments, synthesizer circuit 206 d can be configured to generate a carrier frequency as an output frequency, while in other embodiments, the output frequency can be a multiple of the carrier frequency (e.g., twice the carrier frequency, four times the carrier frequency) and used in conjunction with a quadrature generator and frequency divider circuit to generate multiple signals at the carrier frequency with multiple phases different from each other. In some embodiments, the output frequency can be an LO frequency (f _LO ). In some embodiments, RF circuit 206 can include an IQ/polarity converter.

FEM circuitry 208 may include a receive signal path that may include circuitry configured to operate on RF signals received from one or more antennas 210A-D, amplify the received signals, and provide the amplified versions of the received signals to RF circuitry 206 for further processing. FEM circuitry 208 may also include a transmit signal path that may include circuitry configured to amplify signals provided by RF circuitry 206 for transmission by one or more of the one or more antennas 210A-D.

In some embodiments, the FEM circuitry 208 may include a transmit/receive (TX/RX) switch to switch between transmit and receive modes of operation. The FEM circuitry may include a receive signal path and a transmit signal path. The receive signal path of the FEM circuitry may include a low noise amplifier (LNA) to amplify received RF signals and provide the amplified received RF signals as outputs (e.g., to the RF circuitry 206). The transmit signal path of the FEM circuitry 208 may include a power amplifier (PA) for amplifying input RF signals (e.g., provided by the RF circuitry 206) and one or more filters for generating RF signals for subsequent transmission (e.g., via one or more of the one or more antennas 210). In some embodiments, the UE 200 may include additional components such as memory/storage, a display, a camera, sensors, and/or input/output (I/O) interfaces.

FIG3 is a functional diagram of an evolved Node B (eNB) according to some embodiments. It should be noted that in some embodiments, eNB 300 may be a stationary, non-mobile device. eNB 300 may be suitable for use as eNB 120, as shown in FIG1 . The components of eNB 300 may be included in a single device or multiple devices. 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 UE 200, other eNBs, other UEs, or other devices using one or more antennas 301A-B. For example, PHY circuitry 302 may perform various encoding and decoding functions, including formatting baseband signals for transmission and decoding received signals. For example, PHY circuitry 302 may include LDPC encoder/decoder functionality, and may optionally include other technologies such as block codes, convolutional codes, turbo codes, etc., which may be used to support legacy protocols. Embodiments of the modulation/demodulation and encoder/decoder functionality are not limited to these examples and may include other appropriate functionality in other embodiments. As another example, the transceiver 305 may perform various transmission and reception functions, such as conversion of signals between baseband and radio frequency (RF) ranges. Thus, the physical layer circuitry 302 and the transceiver 305 may be separate components or may be part of a combined component. Furthermore, some of the functions described in connection with signal transmission and reception may be implemented by a combination including one, any, or all of the physical layer circuitry 302, the transceiver 305, and other components or layers. The eNB 300 may also include medium access control (MAC) layer circuitry for controlling access to the wireless medium. The eNB 300 may also include processing circuitry 306 and memory 308 configured to perform the operations described herein. The eNB 300 may also include one or more interfaces 310 that may enable communication with other components, including other eNBs 104 ( FIG. 1 ), components within the EPC 120 ( FIG. 1 ), or other network components. Additionally, interface 310 may enable communication with other components, including components external to the network, that may not be shown in Figure 1. Interface 310 may be wired or wireless or a combination thereof.

Antennas 210A-D (in the UE) and antennas 301A-B (in the eNB) may include one or more directional or omnidirectional antennas, including, for example, dipole antennas, monopole antennas, patch antennas, loop antennas, microstrip antennas, or other types of antennas suitable for RF signal transmission. In some multiple-input or multiple-output (MIMO) embodiments, antennas 210A-D, 301A-B may be effectively separated to exploit spatial diversity and potentially different channel characteristics.

In some embodiments, the UE 200 or 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 capabilities, a netbook, a wireless phone, 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 can wirelessly receive or transmit information. In some embodiments, the UE 200 or eNB 300 may be configured to operate according to 3GPP standards, but the scope of the embodiments is not limited in this respect. The mobile device or other device 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, a speaker, and other mobile device components. The display may be an LCD screen including a touch screen.

Although the UE 200 and the eNB 300 are each shown as having multiple separate functional elements, one or more of these functional elements may be combined and may be implemented by a combination of software-configured elements (e.g., a processing element including a digital signal processor (DSP)) or other hardware elements. For example, some elements may include 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 circuits for performing at least the functions described herein. In some embodiments, a functional element may refer to one or more processes running on one or more processing elements.

Embodiments may be implemented with 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-transient mechanism for storing information in a machine (e.g., computer) readable form. For example, a computer-readable storage device may include a read-only memory (ROM), a random access memory (RAM), a magnetic disk storage medium, an optical storage medium, a flash memory device, 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.

It should be noted that in some embodiments, the apparatus used by UE 200 or eNB 300 may include the various components of UE 200 or eNB 300 as shown in Figures 2 and 3. Therefore, the techniques and operations described herein with respect to UE 200 (or 104) can be applied to apparatus for UEs. In addition, the techniques and operations described herein with respect to eNB 300 (or 120) can be applied to apparatus for eNBs.

Although specific durations (eg, time interval durations, transmission times, etc.) and specific bit sequence sizes are mentioned herein, the present disclosure is not limited in this regard, and the specific sequence number designations are for illustrative purposes only.

FIG4 illustrates an unlicensed uplink transmission (GUL) according to an example embodiment. Referring to FIG4 , communication 400 may occur in a MulteFire system, for example, between a UE 104 and an eNB 120. The UE 104 and the eNB 120 may communicate in one or more communication bands in an unlicensed spectrum that may be shared with a Wi-Fi station (e.g., an access point) 402.

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

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

In an example, the eNB may transmit DL control information 412A after the GUL 410 and within a 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 a subsequent subframe (e.g., before a scheduled DL burst transmission 414 after performing the LBT).

4 also shows an eNB DL transmission burst 414 with a UL grant and a subsequent UL transmission burst 416 as a result of the grant. The second UE (UE2) may perform an LBT procedure 418 and a GUL 420 followed by a DL control information transmission 422 by the eNB.

In an example, eNB 120 may be associated with a cell that includes UEs that may perform unlicensed UL transmissions as well as scheduled DL/UL transmissions.One or more techniques described herein may be used to control the impact of unlicensed uplink transmissions on scheduled transmissions.

In an example, the eNB 120 may use L1/L2 signaling to control which UEs are allowed to transmit autonomously. More specifically, the eNB 120 may send downlink control information (DCI) as L1 signaling or radio resource control (RRC) information as L2 signaling to one or more UEs to indicate whether unlicensed uplink transmission is allowed. For example, the L1/L2 signaling may be sent on a common physical downlink control channel (cPDCCH) to all UEs associated with the eNB's cell. When the L1/L2 signaling is sent on the cPDCCH or as system information, all UEs are informed whether unlicensed uplink transmission is allowed. In another example, the L1 or L2 signaling may be sent to a specific UE via a physical downlink control channel (PDCCH) or UE-specific RRC signaling to inform the specific UE whether unlicensed uplink transmission is allowed. In addition, the L1 or L2 signaling sent on the PDCCH may be used to inform a group of UEs whether unlicensed uplink transmission is allowed.

In an example, the eNB 120 can control the possible number of UEs based on various indications from the UE. If the UE has UL data to send, the UE 104 can transmit a buffer status report (BSR) indicating the traffic status at the UE. The eNB 120 can then send L1 or L2 signaling to the UE to allow ungranted uplink transmission based on the BSR.

In another example, eNB 120 may determine whether an unlicensed uplink transmission is required for the UE based on the congestion experience at the UE. If the UE experiences severe congestion during channel access, the eNB may increase UL transmission opportunities by allowing the UE to perform unlicensed uplink transmissions. For example, the congestion status may be based on the rate of UL grant failures. More specifically, if the UE is unable to send a scheduled PUSCH transmission for a specific number of UL grants, the eNB may signal the UE to perform an unlicensed uplink transmission. In this regard, unlicensed uplink transmissions may increase UL contention opportunities. In an example, the eNB may signal the UE to perform an unlicensed uplink transmission after the UE's scheduled uplink transmission fails a specific number of times.

In an example, the UE may 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 ungranted uplink transmissions to avoid coinciding with scheduled transmissions.

FIG5 illustrates an example unlicensed UL transmission (GUL) within a restricted timing window according to an example embodiment. Referring to FIG5 , communication 500 illustrates how an eNB can restrict the operation of unscheduled communications (e.g., unlicensed uplink transmissions) to a specific, known period. More specifically, the eNB can inform the UE of a DTxW period 502A for a repetitive discovery reference signal (DRS) transmission window (DTxW) 504. 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 an eNB-initiated paging opportunity. DRS 508 can include, for example, a primary synchronization signal (PSS), a secondary synchronization signal (SSS), system information transmitted on a physical broadcast channel (PBCH), and a cell-specific reference signal (CRS). The eNB can inform the UE of an allowed unlicensed transmission interval 506A, which is outside the restricted DTxW 504 (e.g., 504A). In another example, the eNB can indicate available time domain resources, for example, in the form of a set of subframes that can be used for the GUL. RRC signaling may be used for such indication. A set of subframes available for GUL may be indicated by an N-bit bitmap, and the pattern may be repeated every N milliseconds (ms). In one example, N=40.

As shown in FIG5 , scheduled downlink and uplink transmissions 512 and unlicensed uplink transmissions 514 may occur within the allowed unlicensed transmission interval 506A. Similarly, the eNB may transmit DRS 516 and a portion of scheduled downlink transmissions 518 during DTxW 504B within the DTxW period 502B. Unlicensed uplink transmissions 520 may be performed outside of DTxW 504B. In view of this, by limiting unlicensed uplink transmissions to time intervals outside of DTxW, the eNB may minimize the impact of unlicensed uplink transmissions on critical downlink transmissions (e.g., DRS transmissions).

In an example, the maximum duration of unlicensed UL transmissions may be limited. For example, the eNB may indicate to the UE that the maximum duration for unlicensed UL transmissions is 4 ms, and the UE may transmit within a 4 ms interval, after which the UE needs to re-contention for the channel (and perform LBT).

In an example, the eNB and/or UE may sense the availability (or absence) of Wi-Fi stations and may activate or deactivate unlicensed UL transmissions based on such availability. For example, the eNB may deactivate unlicensed UL transmissions if there are no Wi-Fi stations operating in the unlicensed spectrum within the eNB cell.

6A and 6B illustrate example downlink (DL) transmissions following an ungranted UL transmission according to example embodiments.

In a communication environment dominated by scheduled transmissions from the eNB and Wi-Fi stations, the performance of unlicensed UL transmissions may be poor because there is less opportunity for HARQ ACK/NACK feedback, UL CSI, and/or MCS information to be transmitted from the eNB in response to the unlicensed UL transmission. To increase the transmission opportunity of DL control information, the DL control information may follow the GUL and after the eNB performs single-interval LBT. In an example, if the DL control information is within the maximum channel occupancy time (MCOT) initialized by the UE associated with the eNB, the eNB does not perform LBT on the DL control information. For example, and referring to communication 600A in FIG6A, an unlicensed uplink transmission 606A may occur before an unlicensed uplink transmission 608A. Downlink control information 610A, including ACK/NACK, UL CSI, and/or MCS, in response to the unlicensed uplink transmission 606A may occur after the unlicensed uplink transmission 608A. In addition, downlink control information 614A in response to unlicensed uplink transmission 608A may be delayed 620A and may be transmitted after unlicensed uplink transmission 612A. Similarly, downlink control information 616A in response to unlicensed uplink transmission 612A may be delayed 622A and may be transmitted after the scheduled (or Wi-Fi) transmission, as shown in FIG6A. In the case where DL control information (e.g., 616A in FIG6A) is transmitted outside of a TxOP, Type 4 LBT is performed for the DL control information transmission.

6B , unlicensed uplink transmission 602B may occur before unlicensed uplink transmission 604B. Downlink control information 606B, including ACK/NACK, UL CSI, and/or MCS, in response to unlicensed uplink transmission 602B may occur after unlicensed uplink transmission 604B. Furthermore, downlink control information 610B in response to unlicensed uplink transmission 604B may be delayed and may be transmitted after unlicensed uplink transmission 608B. Similarly, downlink control information 614B in response to unlicensed uplink transmission 608B may be delayed and may be transmitted during scheduled DL burst 612B. In these examples, DL control information 606B and 610B may be subjected to single-interval LBT if it is within the MCOT initiated by the UE transmitting the 602B/604B/608B GUL, or may not be subjected to LBT if it is, for example, within 16us from the end of the previous UL transmission and within the MCOT initiated by the UE with the GUL transmission. In the example of DL control information 614B, since the eNB has already performed Type 4 LBT on the DL burst 612B, LBT or single-interval LBT is not performed to transmit the DL control information 614B. In the case where DL control information (e.g., 614B) is transmitted outside of a transmit opportunity (TxOP), Type 4 LBT is performed on the DL control information transmission.

In an example, to reduce the latency of receiving DL control information from the eNB, the UE can autonomously perform a LBT procedure (e.g., Type 4 LBT) to request feedback for a pending HARQ process (e.g., an unacknowledged ungranted UL transmission). This contention can be used to send ACK/NACK feedback in addition to the eNB's Type 4 LBT contention. After the UE performs the ungranted UL transmission requesting DL control information, the eNB can immediately send a HARQ ACK/NACK using a very short LBT procedure (or no LBT procedure), as shown in communication 600C in FIG6C.

6C illustrates an example downlink (DL) transmission following an ungranted UL transmission requesting an acknowledgment, according to an example embodiment.

6C , unlicensed uplink transmission 608C may occur before unlicensed uplink transmission 610C. Downlink control information 612C, including ACK/NACK, UL CSI, and/or MCS, in response to unlicensed uplink transmission 608 may occur after unlicensed uplink transmission 610C. Furthermore, downlink control information 616C in response to unlicensed uplink transmission 610C may be delayed and may be transmitted after unlicensed uplink transmission 614C. Similarly, downlink control information in response to unlicensed uplink transmission 614C may be delayed 626C and may be transmitted after scheduled transmissions 618C and 624C. In an example, to reduce the delay in receiving downlink control information in response to the unlicensed uplink transmission 614C, the UE may perform LBT and unlicensed UL transmission 620C, requesting DL control information (including ACK/NACK, UL CSI, and/or MCS in response to the unlicensed uplink transmission 614C), and then, after the unlicensed UL transmission 620C, transmit DL control information 622C in response to the unlicensed uplink transmission 614C.

7 and 8 are flow diagrams illustrating example functionality for performing unlicensed uplink transmissions according to some embodiments. Referring to FIG. 7 , example method 700 may begin at 702 by decoding control information received on one or more channels of unlicensed spectrum. The control information may include an indicator that unlicensed uplink (UL) transmissions are permitted without a prior UL grant. For example, eNB 120 may use physical layer (i.e., L1) signaling or higher layer signaling (e.g., DCI or RRC signaling) to indicate to the UE that unlicensed UL transmissions are permitted within specific resources. At 704, a listen-before-talk (LBT) procedure may be performed on one or more channels of the unlicensed spectrum to determine whether an available channel exists in the unlicensed spectrum channels. For example, UE 104 may perform LBT procedure 408. At 706, once it is determined that a channel is available, UL control information and data may be encoded for transmission on a physical uplink shared channel (PUSCH), a short physical uplink control channel (sPUCCH), and/or an extended PUCCH (ePUCCH) using an unlicensed UL transmission. For example, a GUL 410 may be performed by the UE without a prior UL grant from the eNB. In this regard, an unlicensed uplink transmission 410 is an unscheduled, unlicensed transmission performed on an available channel of an unlicensed spectrum without a UL grant.

8 , example method 800 may begin at 802 when control information may be encoded for transmission on one or more channels of unlicensed spectrum. For example, the eNB 120 may encode physical layer or higher layer signaling (e.g., DCI or RRC signaling) that may include an indication that unlicensed uplink (UL) transmissions are permitted without a prior UL grant within specific resources. At 804, UL control information and data may be decoded. The control information and data may be received on the sPUCCH/ePUCCH and/or the physical uplink shared channel (PUSCH) using unlicensed UL transmissions. For example, the control information and data may be received from the UE via an unlicensed uplink transmission, where the unlicensed uplink transmission is an unscheduled unlicensed transmission performed on one or more channels of unlicensed spectrum without a UL grant. At 806, acknowledgement (ACK) feedback or negative acknowledgement (NACK) feedback may be encoded in response to the unlicensed uplink transmission. For example, the eNB may encode DL control information 412A for transmission to the UE, the DL control information including ACK/NACK indication, UL CSI, and/or MCS information.

Figure 9 shows a block diagram of a communication device (e.g., an eNB or UE) according to some embodiments. In alternative embodiments, the communication device 900 can operate as a standalone device or can be connected (e.g., networked) to other communication devices. In a networked deployment, the communication device 900 can operate as a server communication device, a client communication device, or both in a server-client network environment. In an example, the communication device 900 can be used as a peer communication device in a peer-to-peer (P2P) (or other distributed) network environment. The communication device 900 can be a UE, an eNB, a PC, a tablet PC, a STB, a PDA, a mobile phone, a smartphone, network equipment, a network router, a switch or a bridge, or any communication device capable of (sequentially or otherwise) executing instructions specifying the actions to be taken by the communication device. In addition, although only a single communication device is shown, the term "communication device" should also be considered to include any collection of communication devices that individually or jointly execute a set (or multiple sets) of instructions to implement any one or more of the methods discussed herein (e.g., cloud computing, software as a service (SaaS) or other computer cluster configurations).

Examples as described herein may include logic or multiple components, modules, or mechanisms, or may operate thereon. A module is a tangible entity (e.g., hardware) that can perform a specified operation and can be configured or arranged in a particular manner. In an example, a circuit can be arranged (e.g., internally or relative to an external entity such as other circuits) as a module in a specified manner. In an example, all or part of one or more computer systems (e.g., independent, client or server computer systems) or one or more hardware processors can be configured to operate as a module that performs a specified operation by firmware or software (e.g., instructions, application program parts or applications). In an example, software may reside on a communication device readable medium. In an example, the software causes the hardware to perform a specified operation when executed by the underlying hardware of the module.

Thus, the term "module" is understood to include tangible entities, i.e., entities that are physically constructed, specifically configured (e.g., hardwired), or temporarily (e.g., provisionally) configured (e.g., programmed) to operate in a specified manner or to perform part or all of any of the operations described herein. Considering examples where modules are temporarily configured, each module need not be instantiated at any time. For example, where a module comprises a general-purpose hardware processor configured using software, the general-purpose hardware processor may be configured as corresponding different modules at different times. The software may configure the hardware processor accordingly, for example, so as to configure a particular module at one time and another module at another time.

The 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 interconnect (e.g., a bus) 908. The communication device 900 may also 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, the input device 912, and the UI navigation device 914 may be a touch screen display. The communication device 900 may also include a storage device (i.e., a drive unit) 916, a signal generating device 918 (e.g., a speaker), a network interface device 920, and one or more sensors 921 (e.g., a global positioning system (GPS) sensor, a compass, an accelerometer, or other sensors). 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 with or control one or more peripheral devices (e.g., a printer, a card reader, etc.).

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 (e.g., software) 924 that are embodied or used by any one or more of the techniques or functionality described herein. During execution by the communication device 900, the instructions 924 may also reside partially or completely within the main memory 904, within the static memory 906, or within the hardware processor 902. 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 a communication device readable medium.

Although the communication device readable medium 922 is shown 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 one or more instructions 924.

The term "communication device readable medium" may include any medium capable of storing, encoding, or carrying instructions that are executed by the communication device 900 and cause the communication device 900 to perform any one or more of the techniques of the present disclosure, or any medium capable of storing, encoding, or carrying data structures used or associated with these instructions. Non-limiting examples of communication device readable media may include solid-state memory, 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, the communication device readable medium may include non-transitory communication device readable media. In some examples, the communication device readable medium may include communication device readable media that is not a transient propagation signal.

The instructions 924 may also be sent or received via a communication network 926 using a transmission medium, the sending and receiving being via a network interface device 920 utilizing a plurality of transmission 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), a mobile phone network (e.g., a cellular network), a plain old telephone (POTS) network, a wireless data network (e.g., the Institute of Electrical and Electronics Engineers (IEEE) 802.11 series of standards, the IEEE 802.16 series of standards), the IEEE 802.15.4 series of standards, the Long Term Evolution (LTE) series of standards, the Universal Mobile Telecommunications System (UMTS) series of standards, a peer-to-peer (P2P) network, etc. In an example, the network interface device 920 may include one or more physical jacks (e.g., Ethernet, coaxial, or telephone jacks) or one or more antennas to connect to the communication network 926. In an example, the network interface device 920 may include multiple antennas to communicate wirelessly using at least one of single-input multiple-output (SIMO), multiple-input multiple-output (MIMO), or multiple-input single-output (MISO) technology. In some examples, the network interface device 920 may communicate wirelessly using multi-user MIMO technology. The term "transmission medium" should be taken to include any intangible medium capable of storing, encoding, or carrying instructions executed by the communication device 900, and includes digital or analog communication signals or other intangible media to facilitate communication of the software.

Additional notes and examples:

Example 1 is a device of a user equipment (UE), comprising: a memory; and a processing circuit configured to: decode control information received on one or more channels of an unlicensed spectrum, the control information including an indication that an unlicensed UL transmission (GUL) is allowed without a prior uplink (UL) authorization; perform a listen-before-talk (LBT) process on one or more channels of the unlicensed spectrum to determine whether there is an available channel in the channel; and when it is determined that the channel is available, encode the UL control information and data for transmission using the unlicensed UL transmission, wherein the unlicensed uplink transmission is an unscheduled transmission performed on a channel of the unlicensed spectrum without a UL authorization.

In Example 2, the subject matter of Example 1 can optionally include wherein the control information is downlink control information (DCI) received on a common physical downlink control channel (cPDCCH) in an unlicensed spectrum.

In Example 3, the subject matter of any one or more of Examples 1-2 may optionally include: wherein the memory stores UL control information and data to be transmitted using the unlicensed UL transmission.

In Example 4, the subject matter of any one or more of Examples 1-3 may optionally include: wherein the control information is radio resource control (RRC) information received on a physical downlink shared channel (PDSCH) in an unlicensed spectrum.

In Example 5, the subject matter of any one or more of Examples 1-4 optionally includes: wherein the UL control information includes at least one of the following items: a UE identification (UEID) of the UE; a modulation and coding scheme (MCS) used by the UE; a redundancy version (RV) used by the UE for data transmission; a new data indicator (NDI) associated with the data transmission; a length of the UL burst for transmitting the UL control information; and a maximum channel occupancy time (MCOT) reserved by the performed LBT.

In Example 6, the subject matter of any one or more of Examples 1-5 may optionally include: wherein the processing circuit is configured to: encode a buffer status report (BSR) for transmission to an evolved Node B (eNB), the BSR indicating transmission congestion of a scheduled UL transmission of the UE.

In Example 7, the subject matter of Example 6 may optionally include: the control information including an indicator allowing unlicensed UL transmission being received in response to the BSR.

In Example 8, the subject matter of any one or more of Examples 1-7 optionally includes: wherein the processing circuit is configured to: monitor a common physical downlink control channel (cPDCCH) within an unlicensed spectrum for scheduled transmissions; and detect the presence of burst information of downlink (DL) transmissions scheduled by an evolved Node B (eNB) indicated by the cPDCCH and/or scheduled UL transmissions in the unlicensed spectrum.

In Example 9, the subject matter of Example 8 may optionally include wherein the processing circuit is configured to defer ungranted uplink transmissions to avoid being concurrent with scheduled DL transmissions and/or scheduled UL transmissions.

In Example 10, the subject matter of any one or more of Examples 1-9 optionally includes: wherein the processing circuit is configured to: decode second downlink (DL) control information received on one or more channels of an unlicensed spectrum, the second DL control information including acknowledgement (ACK)/negative acknowledgement (NACK) signaling in response to an unlicensed uplink transmission.

In Example 11, the subject matter of any one or more of Examples 9-10 may optionally include: wherein the second control information is received during a maximum channel occupancy time (MCOT) reserved by the UE during the LBT procedure.

In Example 12, the subject matter of any one or more of Examples 1-11 may optionally include: wherein the processing circuit is configured to: decode signaling indicating periodicity of DRS transmission within DTxW; and restrict unlicensed UL transmissions to time intervals outside of DTxW.

In Example 13, the subject matter of any one or more of Examples 1-12 may optionally include wherein the processing circuit is configured to decode the indication of available time domain resources that can be used for unlicensed UL transmission.

In Example 14, the subject matter of any one or more of Examples 1-13 may optionally include: wherein the available time domain resources include a set of available subframes, and wherein the indication is an N-bit bitmap, the N-bit pattern repeating every N ms.

In Example 15, the subject matter of any one or more of Examples 1-14 may optionally include: wherein the control information includes an indication of a maximum UL transmission duration and the processing circuit is configured to: limit the duration of the unauthorized UL transmission to within the maximum UL transmission duration.

Example 16 is an apparatus of an evolved Node B (eNB), the apparatus comprising: a memory; and a processing circuit configured to: encode control information for transmission on one or more channels of an unlicensed spectrum, the control information comprising an indication that unlicensed uplink (UL) transmissions are permitted without a prior uplink authorization; decode UL control information and data received using the unlicensed UL transmission, wherein the unlicensed uplink transmission is an unscheduled transmission performed on one or more channels of the unlicensed spectrum; and encode acknowledgement (ACK) feedback or negative acknowledgement (NACK) feedback in response to the unlicensed uplink transmission.

In Example 17, the subject matter of Example 16 may optionally include: wherein the processing circuit is configured to: encode a UL grant for transmission to the UE, the UL grant being associated with the scheduled UL transmission; and detect a number of failures of the scheduled UL transmission.

In Example 18, the subject matter of any one or more of Examples 16-17 may optionally include wherein the memory stores control information for transmission on one or more channels of an unlicensed spectrum.

In Example 19, the subject matter of any one or more of Examples 17-18 may optionally include: wherein the processing circuit is configured to: encode control information indicating that unauthorized UL transmissions are allowed in response to the detected number of failures of the scheduled UL transmissions.

In Example 20, the subject matter of any one or more of Examples 16-19 optionally includes: wherein, in order to encode control information, the processing circuit is configured to: encode downlink control information (DCI), the downlink control information including an indicator that unlicensed UL transmissions are permitted to be transmitted on a common physical downlink control channel (cPDCCH) within an unlicensed spectrum.

In Example 21, the subject matter of any one or more of Examples 16-20 optionally includes: wherein, in order to encode the control information, the processing circuit is configured to: encode radio resource control (RRC) information, the RRC information including an indicator that the unlicensed UL transmission is permitted to be transmitted on a physical downlink shared channel (PDSCH) within the unlicensed spectrum.

In Example 22, the subject matter of any one or more of Examples 16-21 optionally includes: wherein the processing circuit is configured to: decode a buffer status report (BSR) from a user equipment (UE), the BSR indicating transmission congestion of a scheduled UL transmission of the UE.

In Example 23, the subject matter of Example 22 may optionally include wherein the processing circuit is configured to encode control information having an indication of allowing unlicensed UL transmissions to be transmitted on one or more channels of the unlicensed spectrum in response to the BSR.

In Example 24, the subject matter of any one or more of Examples 22-23 may optionally include wherein the processing circuit is configured to decode the second unlicensed UL transmission, the second unlicensed UL transmission comprising a request for acknowledgement of the unlicensed UL transmission.

In Example 25, the subject matter of Example 24 may optionally include: wherein the processing circuit is configured to: encode a second acknowledgement (ACK)/negative acknowledgement (NACK) feedback responsive to the unlicensed uplink transmission responsive to the second unlicensed UL transmission.

Example 26 is a computer-readable storage medium storing instructions, the instructions being executed by one or more processors of a user equipment (UE), the one or more processors being used to configure the UE to: decode an indication of a discovery reference signal (DRS) transmission window (DTxW) period, the DTxW period indicating the periodicity of DRS transmission within the DTxW; decode control information received on one or more channels of an unlicensed spectrum, the control information including an indication that unlicensed UL transmissions are allowed without a prior uplink (UL) authorization; perform a listen-before-talk (LBT) procedure on one or more channels of the unlicensed spectrum; and send encoded UL control information and data on a physical uplink shared channel (PUSCH), a short physical uplink control channel (sPUCCH) and/or an extended PUCCH (ePUCCH) of the unlicensed spectrum using unlicensed UL transmissions, wherein the unlicensed uplink transmissions are performed in time intervals outside of the DTxW without a UL authorization.

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 an unlicensed spectrum for scheduled transmissions; and detect the presence of burst information of downlink (DL) transmissions scheduled by an evolved Node B (eNB) and/or scheduled UL transmissions in the unlicensed spectrum indicated by the cPDCCH.

In Example 28, the subject matter of Example 27 may optionally include wherein the one or more processors further configure the UE to defer unlicensed uplink transmissions to avoid coexistence with scheduled DL transmissions and/or scheduled UL transmissions scheduled by an associated eNB.

In Example 29, the subject matter of any one or more of Examples 27-28 optionally includes: wherein the one or more processors further configure the UE to: receive second control information on one or more channels of the unlicensed spectrum, the second control information including acknowledgment (ACK)/negative acknowledgment (NACK) feedback in response to the unlicensed uplink transmission.

In Example 30, the subject matter of Example 29 may optionally include: wherein the second control information is received during a maximum channel occupancy time (MCOT) reserved by the UE during the LBT procedure.

In Example 31, the subject matter of any one or more of Examples 26-30 may optionally include wherein the one or more processors further configure the UE to detect a failure to receive a first acknowledgement (ACK)/negative acknowledgement (NACK) signaling in response to an unauthorized uplink transmission.

In Example 32, the subject matter of Example 31 may optionally include wherein the one or more processors further configure the UE to: encode a request for acknowledgment of the unlicensed UL transmission in response to the detection failure; and send the request for acknowledgment using a second unlicensed UL transmission.

In Example 33, the subject matter of Example 32 optionally includes: wherein the processing circuit is configured to: decode a second acknowledgement (ACK)/negative acknowledgement (NACK) feedback associated with the unauthorized uplink transmission, the second ACK/NACK signaling being received in response to the second unauthorized UL transmission.

Example 34 is an apparatus of a user equipment (UE), the apparatus comprising an apparatus for decoding an indication of a discovery reference signal (DRS) transmission window (DTxW) period, the DTxW period indicating the periodicity of DRS transmission within the DTxW; an apparatus for decoding control information received on one or more channels of an unlicensed spectrum, the control information comprising an indication that unlicensed UL transmissions are allowed without a prior uplink (UL) authorization; an apparatus for performing a listen-before-talk (LBT) procedure on one or more channels of the unlicensed spectrum; and an apparatus for sending encoded UL control information and data on a physical uplink shared channel (PUSCH), a short physical uplink control channel (sPUCCH) and/or an extended PUCCH (ePUCCH) of the unlicensed spectrum using an unlicensed UL transmission, wherein the unlicensed uplink transmission is performed in a time interval outside of the DTxW without a UL authorization.

In Example 35, the subject matter of Example 34 optionally includes: an apparatus for monitoring a common physical downlink control channel (cPDCCH) within an unlicensed spectrum for scheduled transmissions; and an apparatus for detecting the presence of burst information of downlink (DL) transmissions scheduled by an evolved Node B (eNB) and/or scheduled UL transmissions in the unlicensed spectrum indicated by the cPDCCH.

In Example 36, the subject matter of Example 35 may optionally include means for deferring unlicensed uplink transmissions to avoid coexistence with scheduled DL transmissions and/or scheduled UL transmissions scheduled by an associated eNB.

In Example 37, the subject matter of any one or more of Examples 35-36 optionally includes: an apparatus for receiving second control information on one or more channels of an unlicensed spectrum, the second control information comprising acknowledgment (ACK)/negative acknowledgment (NACK) feedback in response to the unlicensed uplink transmission.

In Example 38, the subject matter of Example 37 may optionally include: wherein the second control information is received during a maximum channel occupancy time (MCOT) reserved by the UE during the LBT procedure.

In Example 39, the subject matter of any one or more of Examples 34-38 may optionally include means for detecting a failure to receive a first acknowledgement (ACK)/negative acknowledgement (NACK) signaling in response to an ungranted uplink transmission.

In Example 40, the subject matter of Example 39 may optionally include: means for encoding a request for acknowledgment of the unlicensed UL transmission in response to detecting a failure; and means for sending the request for acknowledgment using a second unlicensed UL transmission.

In Example 41, the subject matter of Example 40 optionally includes means for decoding a second acknowledgement (ACK)/negative acknowledgement (NACK) feedback associated with the unlicensed uplink transmission, the second ACK/NACK signaling being received in response to the second unlicensed UL transmission.

The publications, patents, and patent documents referenced in this document are incorporated herein by reference in their entirety, as if individually incorporated by reference. In the event of inconsistent usages between this document and those documents incorporated by reference, the usage in the incorporated reference(s) supplements that in this document; for completely inconsistent usages, the usage in this document controls.

The above description is intended to be illustrative, not restrictive. For example, the above examples (and one or more aspects thereof) may be used in conjunction with other examples. For example, a person skilled in the art may use other embodiments after reading the above description. The abstract is intended to enable the reader to quickly understand the essence of the present disclosure. It should be understood that the abstract will not be used to interpret or limit the scope or meaning of the claims. In addition, in the above detailed description section, various features may be combined together to form the present disclosure. However, the claims may not show every feature disclosed herein, as the embodiments may embody a subset of the features. In addition, the embodiments may include fewer features than those disclosed in a particular example. Therefore, the appended claims are hereby incorporated into the detailed description section, with the claims themselves serving as separate embodiments. The scope of the embodiments disclosed herein will be determined with reference to the appended claims and the full scope of equivalents to which the claims are entitled.

Claims (25)

1. An apparatus for use in a user equipment (UE), the apparatus comprising: The memory; and the processing circuitry configured to cause the UE to: Receive control information received on one or more channels in unlicensed spectrum, the control information including an indication of allowing autonomous UL transmission in the absence of prior uplink UL authorization; Perform a Listen-Before-Talk (LBT) procedure on one or more channels in the unlicensed spectrum to determine whether an available channel exists; and When the channel is determined to be available, UL control information and data are transmitted to perform transmission using the autonomous UL transmission, wherein the autonomous uplink transmission is an unscheduled transmission performed on the channel in the unlicensed spectrum without UL authorization. 2. The apparatus of claim 1, wherein the control information is downlink control information (DCI) received on the public physical downlink control channel (cPDCCH) in the unlicensed spectrum. 3. The apparatus of claim 1, wherein the memory stores the UL control information and the data for transmission using the autonomous UL transmission. 4. The apparatus of claim 1, wherein the control information is Radio Resource Control (RRC) information received on the Physical Downlink Shared Channel (PDSCH) within the unlicensed spectrum. 5. The apparatus of claim 1, wherein the UL control information includes at least one of the following: The UE's UE identifier, UEID; The modulation and coding scheme (MCS) used by the UE; The UE is used for a redundant version RV for data transmission; A new data indicator (NDI) is associated with the data transmission; The length of the UL burst that transmits the UL control information; and The maximum channel occupancy time (MCOT) reserved by the LBT being executed. 6. The apparatus of claim 1, wherein the processing circuit is configured to: The buffer status report (BSR) is encoded and transmitted to the evolved Node B, the BSR indicating transmission congestion of the UE's scheduled UL transmissions. 7. The apparatus of claim 6, wherein the control information of the indicator that allows the autonomous UL transmission is received in response to the BSR. 8. The apparatus of claim 1, wherein the processing circuit is configured to: Monitoring the Common Physical Downlink Control Channel (cPDCCH) within the unlicensed spectrum used for scheduled transmissions; and The presence of burst information for downlink DL transmissions scheduled by the evolved Node B indicated by the cPDCCH and/or scheduled UL transmissions in the unlicensed spectrum is detected. 9. The apparatus of claim 8, wherein the processing circuit is configured to: The autonomous uplink transmission is delayed to avoid coexistence with scheduled DL transmissions and/or scheduled UL transmissions. 10. The apparatus of claim 1, wherein the processing circuit is configured to: The second downlink DL control information received on one or more channels in the unlicensed spectrum is decoded, the second DL control information including ACK/NACK signaling in response to the autonomous uplink transmission. 11. The apparatus of claim 10, wherein the second DL control information is received during the LBT process during the Maximum Channel Occupancy Time (MCOT) reserved by the UE. 12. The apparatus of claim 1, wherein the processing circuit is configured to: Decode the periodic signaling indicating DRS transmissions within DTxW; and The autonomous UL transmission is restricted to time intervals other than DTxW. 13. The apparatus of claim 1, wherein the processing circuit is configured to: Decode the indications regarding available time-domain resources that can be used for autonomous UL transmission. 14. The apparatus of claim 13, wherein the available time-domain resources comprise a set of available subframes, and wherein the indication is an N-bit bitmap that repeats once every N ms. 15. The apparatus of claim 1, wherein the control information includes an indication of the maximum UL transmission duration, and the processing circuitry is configured to: The duration of the autonomous UL transmission is limited to within the maximum UL transmission duration. 16. An apparatus for use in an evolved Node B, the apparatus comprising: Memory; and processing circuitry configured to cause the evolved node B to: Transmission control information is transmitted on one or more channels in unlicensed spectrum, the control information including instructions regarding permission for autonomous UL transmission in the absence of prior uplink UL authorization; Receive UL control information and data received using the autonomous UL transmission, wherein the autonomous uplink transmission is an unscheduled transmission performed on one or more channels of the unlicensed spectrum without UL authorization; and In response to the autonomous uplink transmission, a transmission acknowledgment (ACK) or a negative acknowledgment (NACK) is provided. 17. The apparatus of claim 16, wherein the processing circuit is configured to: The UL authorization is encoded for transmission to the user equipment (UE), the UL authorization being associated with a scheduled UL transmission; and The number of failures of the scheduled UL transmission is detected. 18. An apparatus for use in communications, the apparatus comprising: A means for decoding an indication of the period of a discovery reference signal DRS transmission window DTxW, the period of which indicates the periodicity of DRS transmissions within the DTxW; A means for decoding control information received on one or more channels in unlicensed spectrum, the control information including an indication of allowing autonomous UL transmission in the absence of prior uplink UL authorization; Means for performing a listen-before-speak (LBT) procedure on one or more channels of the unlicensed spectrum; and A means for transmitting encoded UL control information and data on the Physical Uplink Shared Channel (PUSCH), Short Physical Uplink Control Channel (sPUCCH), and/or Extended PUCCH (ePUCCH) of the unlicensed spectrum using the autonomous UL transmission, wherein the autonomous uplink transmission is performed during time intervals outside the DTxW without UL authorization. 19. The apparatus of claim 18, further comprising: Means for monitoring the Common Physical Downlink Control Channel (cPDCCH) within the unlicensed spectrum used for scheduled transmissions; and A means for detecting the presence of burst information of downlink DL transmissions scheduled by the evolved Node B indicated by the cPDCCH and/or scheduled UL transmissions in the unlicensed spectrum. 20. The apparatus of claim 19, further comprising: Means for delaying the autonomous uplink transmission to avoid coexistence with scheduled DL transmissions and/or scheduled UL transmissions scheduled by the associated evolved Node B. 21. The apparatus of claim 19, further comprising: Means for receiving second control information on one or more channels of the unlicensed spectrum, the second control information including ACK/NACK feedback in response to the autonomous uplink transmission. 22. The apparatus of claim 21, wherein the second control information is received during the maximum channel occupancy time (MCOT) reserved by the UE during the LBT process. 23. The apparatus of claim 18, further comprising: A means for detecting a failure to receive a first ACK/NACK signaling response in response to the autonomous uplink transmission. 24. The apparatus of claim 23, further comprising: A means for encoding a request for acknowledgment of the autonomous UL transmission in response to the detection of the failure; and A means for sending a request for confirmation of the autonomous UL transmission using a second autonomous UL transmission. 25. The apparatus of claim 24, further comprising: A means for decoding a second ACK/NACK feedback associated with the autonomous uplink transmission, the second ACK/NACK signaling being received in response to the second autonomous UL transmission.