CN108781149B - Apparatus for coexistence of unlicensed uplink and scheduled transmissions - Google Patents

Abstract

Disclosed herein is an apparatus of a User Equipment (UE) configured to communicate with an evolved node b (enb). The UE may include a memory and processing circuitry coupled to the memory. The processing circuit may be configured to decode control information received on one or more channels of the unlicensed spectrum. The control information includes an indication that unlicensed Uplink (UL) transmissions are allowed without a prior UL grant. The processing circuit is further configured to perform a Listen Before Talk (LBT) procedure on one or more channels of the unlicensed spectrum to determine whether there is an available channel in the channels. When it is determined that a channel is available, the processing circuitry may encode UL control information and data for transmission using unlicensed UL transmissions. An unlicensed uplink transmission is an unscheduled transmission performed on a channel without an UL grant.

Description

Apparatus for coexistence of unlicensed uplink and scheduled transmissions

Priority declaration

Priority OF united states provisional patent application No.62/311,698 entitled "ENABLING coexistence OF AUTONOMOUS UPLINK TRANSMISSION AT ENB WITH SCHEDULED TRANSMISSION", filed on day 22, 3/22/2016, hereby incorporated by reference in its entirety.

Technical Field

Embodiments relate to wireless communications. Some embodiments relate to wireless networks including a 3GPP (third generation partnership project) network, a 3GPP LTE (long term evolution) network, a 3GPP LTE-a (LTE advanced) network, a MulteFire network, and a 5G network, although the scope of the embodiments is not limited in this respect. Some embodiments relate to unlicensed (or autonomous) uplink transmissions (GUL) for User Equipment (UE). Some embodiments relate to enabling coexistence of unlicensed (or autonomous) uplink transmissions with scheduled transmissions.

Background

As the number of different types of devices communicating with various network devices increases, the use of the 3GPP LTE system also increases. The penetration of mobile devices (user equipment or UEs) in modern society continues to drive the demand for a wide variety of networked devices in many different environments. In various fields of home and work life, the use of networked UEs using the 3GPP LTE system is increasing. A fifth generation (5G) wireless system is coming and it is expected that higher speed, connectivity and availability will be achieved.

LTE and LTE-advanced are standards for wireless communication of high-speed data for User Equipment (UE), such as mobile phones. Carrier aggregation is a technique in LTE-advanced and various wireless systems in which multiple carrier signals operating on 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 may be used in cases where one or more component carriers operate on unlicensed frequencies.

Explosive wireless traffic growth has resulted in a need for increased rates. With mature physical layer technology, further improvements in spectral efficiency would be negligible. On the other hand, insufficient licensed spectrum in the low frequency band causes weakness in data rate increase. Thus, there is an 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 extends the system bandwidth by exploiting the flexible Carrier Aggregation (CA) framework introduced by LTE-advanced systems. The Rel-13 LAA system focuses on the design of DL operation over unlicensed spectrum via CA, while the Rel-14 modified LAA (eLAA) system focuses on the design of UL operation over unlicensed spectrum via CA. More improved operation of LTE systems in unlicensed spectrum is expected in future releases and 5G systems. Possible LTE operations in unlicensed spectrum include, and are not limited to, LTE operations in unlicensed spectrum via Dual Connectivity (DC), or DC-based LAA and standalone LTE systems in unlicensed spectrum, where LTE-based technologies only operate in unlicensed spectrum without the need for an "anchor" in licensed spectrum, a technology known as MulteFire. MulteFire combines the performance advantages of LTE technology with the simplicity of Wi-Fi like deployments, seen as a very important technology component to meet the ever increasing wireless traffic.

Drawings

In the drawings, which are not necessarily drawn to scale, like numerals may indicate like elements in different views. Like numerals having different letter suffixes may represent different instances of detailed components. In the following description of the 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.

Fig. 1 is a block diagram of a system including an evolved node b (enb) and a User Equipment (UE) that may operate in a wireless communication network in accordance with some embodiments described herein.

Fig. 2 is a block diagram of a User Equipment (UE) in accordance with some embodiments.

Fig. 3 is a block diagram of an evolved node b (enb) in accordance with some embodiments.

Fig. 4 illustrates unlicensed uplink transmissions (GUL) according to an example embodiment.

Fig. 5 illustrates an example unlicensed UL transmission (gil) within a restricted timing window according to an example embodiment.

Fig. 6A and 6B illustrate example Downlink (DL) transmissions after an unlicensed UL transmission, according to example embodiments.

Fig. 6C illustrates an example Downlink (DL) transmission after an unlicensed UL transmission requesting an acknowledgement, according to an example embodiment.

Fig. 7 and 8 are flowcharts illustrating example functions for implementing unlicensed uplink transmissions according to some embodiments.

Fig. 9 illustrates a block diagram of a communication device, such as an eNB or UE, in accordance with 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, Licensed Assisted Access (LAA), improved LAA (elaa) and MulteFire communications. The following description and the annexed drawings set forth in detail certain illustrative embodiments that enable those skilled in the art to practice the invention. Other embodiments may incorporate structural, logical, electrical, process, and other changes. Portions and features of some embodiments may be included in or substituted for those of other embodiments and are intended to cover all available equivalents of the described elements.

Fig. 1 is a block diagram of a system including an evolved node b (enb) and a User Equipment (UE) that may operate in a wireless communication network in accordance with some embodiments described herein. The wireless network system 100 includes a UE104 and an eNB120 connected via an air interface 190. UE104 and eNB120 communicate using a system that supports Carrier Aggregation (CA) and uses unlicensed frequency bands (unlicensed frequency bands) such that air interface 190 supports multiple frequency carriers as well as licensed and unlicensed frequency bands. Component carrier 180 and component carrier 185 are shown in fig. 1. Although two component carriers are shown, various embodiments may include any number of two or more component carriers. Various embodiments may operate with any number of licensed channels and any number of unlicensed channels.

Further, in various embodiments described herein, at least one of the component carriers 180, 185 in the air interface 190 comprises 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 the radio spectrum that is not specifically reserved for use by the system. For example, some frequency ranges may be used by communication systems operating in different communication standards, such as frequency bands used by both Institute of Electrical and Electronics Engineers (IEEE)802.11 standards (e.g., "WiFi") and third generation partnership project (3GPP) standards, including LTE and LTE-advanced and enhanced versions of LTE (as discussed below). By contrast, a "licensed channel" or "licensed spectrum" operates under a particular standard, and there is limited interest in that there will be other undesired signals operating under different standards.

Communications over an LTE network may be divided into 10ms frames, each frame containing ten 1ms subframes. Each subframe may in turn contain two 0.5ms slots. Each slot may contain 6-7 symbols, depending on the system used. A Resource Block (RB) (which may also be referred to as a Physical Resource Block (PRB)) may be the smallest unit of resources that may be allocated to a UE. A resource block may be 180kHz wide in frequency and 1 slot long in time. In frequency, a resource block may be 12 subcarriers at 15kHz or 24 subcarriers wide at 7.5 kHz. For most channels and signals, 12 subcarriers may be used per resource block. In Frequency Division Duplex (FDD) mode, the uplink and downlink frames may both be 10ms and may be separated in frequency (full duplex) or time (half duplex). In Time Division Duplex (TDD) mode, uplink and downlink subframes may be transmitted on the same frequency and may be multiplexed in the time domain. A downlink resource grid (grid) may be used for downlink transmission from the eNB to the UE. The resource grid may 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 may correspond to one OFDM symbol and one OFDM subcarrier, respectively. The duration of the resource grid in the time domain may correspond to one time slot. The smallest time-frequency unit in the resource grid may be represented by a resource element. Each resource grid may comprise a plurality of the above-mentioned resource blocks, which describe the mapping of a particular physical channel to a resource element. Each resource block may include 12 (subcarriers) × 14 (symbols) × 168 resource elements.

In some embodiments, a downlink resource grid may be used for downlink transmissions from the eNB120 to the UE104, while uplink transmissions from the UE104 to the eNB120 may utilize similar techniques. The resource grid may be a time-frequency resource grid, referred to as a resource grid or a time-frequency resource grid, which is a physical resource in each downlink in each time slot. Such a representation of the time-frequency plane is a common usage of OFDM systems, making it intuitive for radio resource allocation. Each column and each row of the resource grid may correspond to one OFDM symbol and one OFDM subcarrier, respectively. The duration of the resource grid in the time domain may correspond to one time slot of a radio frame. The smallest time-frequency unit in the resource grid may be represented by a Resource Element (RE). Each resource grid includes a plurality of Resource Blocks (RBs) that describe the mapping of a particular physical channel to resource elements. Each resource block includes a set of resource elements on the frequency domain and may represent a minimum amount of resources that may be currently allocated. There are several different physical downlink channels transmitted using such resource blocks. Two example physical downlink channels are a physical downlink shared channel and a 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 a Physical Downlink Control Channel (PDCCH) and a Physical Downlink Shared Channel (PDSCH). Each subframe may be divided into PDCCH and PDSCH.

The Physical Downlink Shared Channel (PDSCH) carries user data and higher layer signaling to the UE 104. A Physical Downlink Control Channel (PDCCH) carries information on a transport format and resource allocation related to a PDSCH channel, and the like. It also informs the UE104 about transport format, resource allocation, and hybrid automatic repeat request (HARQ) information related to the uplink shared channel. In general, downlink scheduling (e.g., allocating control and shared channel resources to UEs 104 within a cell) may be performed at the eNB120 based on channel quality information fed back from the UEs 104 to the eNB120, and then downlink resource allocation information may be sent to the UEs 104 on a control channel (PDCCH) for (allocated to) the UEs 104.

The PDCCH transmits control information using CCEs (control channel elements). The PDCCH complex-valued symbols are first organized into four groups before being mapped to resource elements, and then sequence-changed using sub-block interleavers for rate matching. Each PDCCH is transmitted using one or more of these Control Channel Elements (CCEs), where each CCE corresponds to nine sets of four physical resource elements called Resource Element Groups (REGs). Four QPSK symbols are mapped to each REG. Depending on the size of Downlink Control Information (DCI) and channel conditions, the PDCCH may be transmitted using one or more CCEs. Four or more different PDCCH formats with different numbers of CCEs may be defined in LTE (e.g., aggregation level, L ═ 1, 2, 4, or 8).

The embodiments described herein may fall within the scope of separate systems in unlicensed spectrum (unlicensed spectrum), including but not limited to multefire (mf), the next version of 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 5GHz band, which has a wide spectrum that is globally common. The 5GHz band in the united states is governed by the Unlicensed National Information Infrastructure (UNII) rules of the Federal Communications Commission (FCC). The main existing system in the 5GHz band is the Wireless Local Area Network (WLAN), especially a communication network based on ieee802.11a/n/ac technology. Since WLAN systems are widely deployed by individuals and operators for carrier-level access traffic 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 procedure in which a radio transmitter first senses the medium and transmits only when the medium is sensed as idle. In an example, the 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). Performing UL grant transmission on component carriers expected for PUSCH transmission after completing the LBT procedure at the eNB. After receiving the UL grant, the scheduled UE expects 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 send PUSCH on the resources indicated by the UL grant.

However, since LBT is required both at the eNB side (e.g., when transmitting UL grants) and at the scheduled UE side (e.g., prior to transmission by the UE), UL performance within the unlicensed spectrum (e.g., during MulteFire operation exclusively within the unlicensed spectrum) may become very poor. In the case where a scheduled system (e.g., an LTE-based system) coexists with an unscheduled autonomous system (i.e., Wi-Fi), degradation in performance may typically occur. In some instances, LTE-based systems may also use a 4 subframe processing delay, so that the first 4 subframes in a transmission burst cannot be configured to the UL, since the 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 4-subframe processing delay), the UE may perform unlicensed UL transmission (grant UL transmission) without the eNB sending a UL grant for PUSCH transmission by the UE. In view of this, the requirement for LBT on both sides may be reduced when an unlicensed UL transmission by the UE occurs, since the eNB will not perform LBT and LBT may be performed only by the UE. Since the UE performing the unlicensed UL transmission does not need to wait for the eNB's UL grant, the extra 4-subframe delay of accessing the channel for UL transmission will also be eliminated, facilitating further performance improvement.

The embodiments of coexistence described herein may operate within the wireless network system 100. In the wireless network system 100, the UE104 and any other UE in the system may be, for example, a laptop computer, a smartphone, a tablet computer, a printer, a machine type device such as a smart meter or a dedicated device for health monitoring, a remote security monitoring system, a smart transportation system, or any other wireless device with or without a user interface. The eNB120 provides network connectivity for the UE104 to a larger network (not shown). Connectivity for the UE104 is provided via an air interface 190 within an eNB service area provided by the eNB 120. In some embodiments, such a larger network may be a wide area network operated by a cellular network provider, or may be the internet. Each eNB service area associated with eNB120 is supported by an antenna integrated with eNB 120. The service area may be divided into a plurality of sectors associated with particular antennas. These sectors may be physically associated with fixed antennas or may be assigned to physical areas, and tunable antennas or antenna settings may be adjusted during beamforming to direct signals to particular sectors. For example, one embodiment of eNB120 includes three sectors, each sector covering a 120 degree area with an antenna array directed at each sector to provide 360 degree coverage around eNB 120.

The UE104 includes control circuitry 105 coupled with transmit circuitry 110 and receive circuitry 115. The transmit circuitry 110 and receive circuitry 115 may each be coupled to one or more antennas. The control circuitry 105 may be adapted to perform operations associated with wireless communications using carrier aggregation. The transmit circuitry 110 and receive circuitry 115 may be adapted to transmit and receive data, respectively. The control circuitry 105 may be adapted or configured to perform various operations such as those described elsewhere in this disclosure relating to UEs. The transmit circuitry 110 may transmit multiple multiplexed uplink physical channels. The plurality of uplink physical channels may be multiplexed according to Time Division Multiplexing (TDM) or Frequency Division Multiplexing (FDM) and carrier aggregation. The transmit circuitry 110 may be configured to receive block data from the control circuitry 105 for transmission over the air interface 190. Similarly, the receive circuitry 115 may receive a plurality of multiplexed downlink physical channels from the air interface 190 and relay the physical channels to the control circuitry 105. The uplink physical channel and the downlink physical channel may be multiplexed according to FDM. The transmit circuitry 110 and receive circuitry 115 may transmit and receive control data and content data (e.g., messages, images, video, etc.) that are structured within data blocks that are communicated by the physical channel.

Fig. 1 also illustrates an eNB120 in accordance with various embodiments. The eNB120 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 via the air interface 190.

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

As described above, communications over the air interface 190 may use carrier aggregation, where multiple different component carriers 180, 185 may be aggregated to carry information between the UE104 and the eNB 120. Such component carriers 180, 185 may have different bandwidths and may be used for uplink communications from the UE104 to the eNB120, downlink communications from the eNB120 to the UE104, 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 units, which may be referred to as primary component carriers, and the other component carriers as secondary component carriers. In some embodiments, a primary component carrier is provided by a primary cell (PCell) and may operate in a licensed frequency band to provide efficient collision-free communication. The primary channel may be used to schedule other channels including unlicensed channels. In view of this, the PCell is the primary cell with which the UE104 communicates and maintains its connection with 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 frequency bands (e.g., eLAA-based UL and DL communications).

In operation, the wireless communication network 100 may include the capability to support the enodebs 120 and UEs 104 communicating over the licensed spectrum. Wireless communication network 100 may also include the capability to support eNodeB 120 and UE104 communicating over unlicensed spectrum (e.g., one or more 5GHz bands). In some examples where transmissions are simultaneously over licensed and unlicensed spectrum, the licensed spectrum transmission may be a primary cell (PCell) transmission and the unlicensed spectrum transmission may be a secondary cell (SCell) transmission. For communication on PCell and SCell, the wireless communication network 100 may use a self-contained frame structure, where control signaling and data may be transmitted in a Time Division Multiplexed (TDM) manner with a single subframe.

In some embodiments, the wireless communication network 100 may include the capability to support the eNodeB 120 and the UE104 to communicate only over unlicensed spectrum (e.g., MulteFire communication). Furthermore, the UE may be configured to perform an unlicensed uplink transmission, as will be described in more detail with reference to fig. 4-9.

As used herein, the term circuitry may refer to, include, or be part of the following components: an Application Specific Integrated Circuit (ASIC), an electronic circuit, a processor (shared, dedicated, or group) or memory that executes one or more software or firmware programs, a combinational logic circuit, or other suitable hardware components that provide the described functionality. In some embodiments, the circuitry may be implemented in, or functions associated with, one or more software or firmware modules. In some embodiments, the circuitry may comprise logic that is operable, at least in part, in hardware. The embodiments described herein may be implemented into a system using any suitably configured hardware or software.

Fig. 2 is a functional diagram of a User Equipment (UE) according to some embodiments. The UE 200 may be suitable for use as the UE104 shown in fig. 1. In some embodiments, the UE 200 may include application circuitry 202, baseband circuitry 204, Radio Frequency (RF) circuitry 206, front-end module (FEM) circuitry 208, and one or more antennas 210A-210D coupled together at least as shown. In some embodiments, other circuitry or arrangements may include one or more elements or components of the application circuitry 202, the baseband circuitry 204, the RF circuitry 206, or the FEM circuitry 208, and in some cases may also include other elements or components. As an example, a "processing circuit" may include one or more elements or components, some or all of which may be included in the application circuitry 202 or the baseband circuitry 204. As another example, a "transceiver circuit" may include one or more elements or components, some or all of which may be included in the RF circuitry 206 or the FEM circuitry 208. However, these examples are not limiting as the processor circuit or transceiver circuit may also include other elements or components in some cases.

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 special-purpose processors (e.g., graphics processors, application processors, etc.). The processor may be coupled with or may include memory/storage and may be configured to execute instructions stored in the memory/storage to enable various applications 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. Baseband circuitry 204 may include one or more baseband processors or control logic to process baseband signals received from the receive signal path of RF circuitry 206 and to generate baseband signals for the transmit signal path of RF circuitry 206. Baseband processing circuitry 204 may interface with application circuitry 202 to generate and process baseband signals and to control operation of 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 generations, generations in development or to be developed in the future (e.g., fifth generation (5G), 6G, etc.). The baseband circuitry 204 (e.g., one or more of the baseband processors 204a-204 d) may handle various radio control functions that support communication with one or more radio networks via the RF circuitry 206. The radio control functions may include, but are not limited to: signal modulation/demodulation, encoding/decoding, radio frequency shifting, etc. In some embodiments, the modulation/demodulation circuitry of the baseband circuitry 204 may include FFT, precoding, or constellation mapping/demapping functionality. In some embodiments, the encoding/decoding circuitry of the baseband circuitry 204 may include Low Density Parity Check (LDPC) encoder/decoder functionality, and optionally some other techniques, such as block codes, convolutional codes, turbo codes, etc., which may be used to support legacy protocols. Embodiments of 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 an evolved universal terrestrial radio access network (E-UTRAN) protocol, including, for example: a Physical (PHY), Medium Access Control (MAC), Radio Link Control (RLC), Packet Data Convergence Protocol (PDCP), or Radio Resource Control (RRC) element. A Central Processing Unit (CPU)204e of the baseband circuitry 204 may be configured to run elements of a protocol stack for signaling of the PHY, MAC, RLC, PDCP, and/or RRC layers. In some embodiments, the baseband circuitry may include one or more audio Digital Signal Processors (DSPs) 204 f. The one or more audio DSPs 204f may include elements for compression/decompression and echo cancellation, and may include other suitable processing elements in other embodiments. In some embodiments, components of the baseband circuitry may be combined as appropriate in a single chip, a single chipset, or disposed on the same circuit board. In some embodiments, some or all of the constituent 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, the baseband circuitry 204 may provide communications compatible with one or more radio technologies. For example, in some embodiments, baseband circuitry 204 may support communication with an Evolved Universal Terrestrial Radio Access Network (EUTRAN) or other Wireless Metropolitan Area Network (WMAN), Wireless Local Area Network (WLAN), Wireless Personal Area Network (WPAN). Embodiments in which the baseband circuitry 204 is configured to support radio communications of multiple wireless protocols may be referred to as multi-mode baseband circuitry.

The RF circuitry 206 may support communication with a wireless network using modulated electromagnetic radiation through a non-solid medium. In various embodiments, the 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 to down-convert RF signals received from FEM circuitry 208 and provide baseband signals to baseband circuitry 204. RF circuitry 206 may also include a transmit signal path that may include circuitry to up-convert baseband signals provided by baseband circuitry 204 and provide RF output signals 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 the RF circuitry 206 may include a mixer circuit 206a, an amplifier circuit 206b, and a filter circuit 206 c. The transmit signal path of the RF circuitry 206 may include filter circuitry 206c and mixer circuitry 206 a. RF circuitry 206 may also include synthesizer circuitry 206d for synthesizing frequencies for use by mixer circuitry 206a of the receive signal path and the transmit signal path. In some embodiments, the mixer circuitry 206a of the receive signal path may be configured to down-convert the RF signal received from the FEM circuitry 208 based on the synthesized frequency provided by the synthesizer circuitry 206 d. The amplifier circuit 206b may be configured to amplify the downconverted signal, and the filter circuit 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 may be a zero frequency baseband signal, but this is not required. In some embodiments, mixer circuit 206a of the receive signal path may comprise a passive mixer, although the scope of the embodiments is not limited in this respect. In some embodiments, the mixer circuitry 206a of the transmit signal path may be configured to up-convert the input baseband signal based on the synthesis frequency provided by the synthesizer circuitry 206d to generate the RF output signal for the FEM circuitry 208. The baseband signal may be provided by the baseband circuitry 204 and may be filtered by the filter circuitry 206 c. Filter circuit 206c may include a Low Pass Filter (LPF), although the scope of the embodiments is not limited in this respect.

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

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

In some embodiments, synthesizer circuit 206d may be a fractional-N synthesizer or a fractional-N/N +1 synthesizer, although the scope of the embodiments is not limited in this respect as other types of frequency synthesizers may be suitable. For example, synthesizer circuit 206d may be a delta-sigma synthesizer, a frequency multiplier, or a synthesizer including a phase locked loop with a frequency divider. The synthesizer circuit 206d may be configured to synthesize an output frequency for use by the mixer circuit 206a of the RF circuit 206 based on the frequency input and the divider control input. In some embodiments, synthesizer circuit 206d may be a fractional-N/N +1 synthesizer. In some embodiments, the frequency input may be provided by a Voltage Controlled Oscillator (VCO), but this is not required. The divider control input may be provided by the baseband circuitry 204 or the application processor 202 depending on the desired output frequency. In some embodiments, the divider control input (e.g., N) may be determined from a look-up table based on the channel indicated by the application processor 202.

Synthesizer circuit 206d of RF circuit 206 may include a frequency divider, a Delay Locked Loop (DLL), a multiplexer, and a phase accumulator. In some embodiments, the divider may be a dual-mode divider (DMD) and the phase accumulator may be a Digital Phase Accumulator (DPA). In some embodiments, the DMD may be configured to divide an input signal by N or N +1 (e.g., carry out based) to provide a fractional division ratio. In some example embodiments, a 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 period into at most Nd equal phase groups, where Nd is the number of delay elements in the delay line. In this manner, 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 206d may be configured to generate a carrier frequency as the output frequency, while in other embodiments, the output frequency may be a multiple of the carrier frequency (e.g., twice the carrier frequency, four times the carrier frequency) and used with a quadrature generator and divider circuit to generate a plurality of signals having a plurality of different phases from one another at the carrier frequency. In some embodiments, the output frequency may be the LO frequency (f)_LO). In some embodiments, the RF circuitry 206 may 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 amplified versions of the received signals to RF circuitry 206 for further processing. The FEM circuitry 208 may also include a transmit signal path that may include circuitry configured to amplify signals provided by the RF circuitry 206 for transmission by one or more of the one or more antennas 210A-D.

In some embodiments, FEM circuitry 208 may include a transmit/receive (TX/RX) switch to switch between transmit mode and receive mode operation. The FEM circuitry may include a receive signal path and a transmit signal path. The receive signal path of the FEM circuitry may include a Low Noise Amplifier (LNA) to amplify the received RF signal and provide the amplified received RF signal as an output (e.g., to RF circuitry 206). The transmit signal path of FEM circuitry 208 may include a Power Amplifier (PA) to amplify an input RF signal (e.g., provided by RF circuitry 206) and one or more filters to generate an RF signal for subsequent transmission (e.g., by one or more of one or more antennas 210). In some embodiments, the UE 200 may include additional elements such as memory/storage, a display, a camera, sensors, and/or input/output (I/O) interfaces.

Fig. 3 is a functional diagram of an evolved node b (enb) in accordance with some embodiments. It should be noted that in some embodiments, eNB300 may be a stationary non-mobile device. eNB300 may be suitable for use as eNB120 shown in fig. 1. The components of eNB300 may be included in a single device or multiple devices. The eNB300 may include physical layer (PHY) circuitry 302 and a transceiver 305, one or both of which physical layer circuitry 302 and transceiver 305 may enable the use of one or more antennas 301A-B to transmit signals to and receive signals from the UE 200, other enbs, other UEs, or other devices. For example, the physical layer circuitry 302 may perform various encoding and decoding functions, which may include formatting of baseband signals for transmission and decoding of received signals. For example, the physical layer circuitry 302 may include LDPC encoder/decoder functionality and optionally some other techniques, such as block codes, convolutional codes, turbo codes, etc., which may be used to support legacy protocols. Embodiments of modulation/demodulation and encoder/decoder functions are not limited to these examples, and other suitable functions may be included in other embodiments. As another example, transceiver 305 may perform various transmit and receive functions, such as conversion of signals between the baseband range and the Radio Frequency (RF) range. Thus, the physical layer circuit 302 and the transceiver 305 may be separate components or may be part of a combined component. Further, some of the described functions related to the transmission and reception of signals may be implemented by a combination including one, any or all of physical layer circuitry 302, transceiver 305, and other components or layers. The eNB300 may also include medium access control layer (MAC) circuitry to control access to the wireless medium. The eNB300 may also include processing circuitry 306 and memory 308 arranged to perform the operations described herein. eNB300 may also include one or more interfaces 310 that may allow communication with other components, including other enbs 104 (fig. 1), components in EPC 120 (fig. 1), or other network components. Further, interface 310 may allow for communication with other components (including components external to the network) that may not be shown in FIG. 1. The 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 transmission of RF signals. In some multiple-input or output (MIMO) embodiments, the antennas 210A-D, 301A-B may be effectively separated to take advantage of spatial diversity and the different channel characteristics that may result.

In some embodiments, the UE 200 or eNB300 may be a mobile device and may be a portable wireless communication device, such as a Personal Digital Assistant (PDA), a laptop or portable computer with wireless communication capability, a netbook, a wireless telephone, a smartphone, a wireless headset, a pager, an instant messaging device, a digital camera, an access point, a television, a wearable device such as a medical device (e.g., a heart rate monitor, a blood pressure monitor, etc.), or other device that may receive or transmit information wirelessly. In some embodiments, UE 200 or eNB300 may be configured to operate in accordance with 3GPP standards, although 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 in accordance with other protocols or standards, including IEEE802.11 or other IEEE standards. In some embodiments, the UE 200, eNB300, or other device may include one or more of a keypad, a display, a non-volatile memory port, multiple antennas, a graphics processor, an application processor, speakers, and other mobile device elements. The display may be an LCD screen including a touch screen.

Although both the UE 200 and the eNB300 are illustrated as having a number of separate functional elements, one or more of the functional elements may be combined and may be implemented by combinations of software-configured elements (e.g., processing elements including Digital Signal Processors (DSPs)) or other hardware elements. For example, some elements may comprise one or more microprocessors, DSPs, Field Programmable Gate Arrays (FPGAs), Application Specific Integrated Circuits (ASICs), Radio Frequency Integrated Circuits (RFICs), and combinations of various hardware and logic circuitry for performing at least the functions described herein. In some embodiments, a functional element may refer to one or more processes running on one or more processing elements.

Embodiments may be implemented in one or a combination of hardware, firmware, and software. Embodiments may also be implemented as instructions stored on a computer-readable storage device, which may be read and executed by at least one processor to perform the operations described herein. A computer-readable storage device may include any non-transitory mechanism for storing information in a form readable by a machine (e.g., a computer). For example, a computer-readable storage device may include Read Only Memory (ROM), Random Access Memory (RAM), magnetic disk storage media, optical storage media, flash memory devices, and other storage devices and media. Some embodiments may include one or more processors and may be configured with instructions stored on a computer-readable storage device.

It should be noted that in some embodiments, the apparatus used by the UE 200 or eNB300 may include various components of the UE 200 or eNB300 as shown in fig. 2 and 3. Thus, the techniques and operations described herein relating to the UE 200 (or 104) may be applied to an apparatus for a UE. Moreover, the techniques and operations described herein relating to eNB300 (or 120) may be applied to an apparatus for an eNB.

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

Fig. 4 illustrates unlicensed uplink transmissions (GUL) according to an example embodiment. Referring to fig. 4, communications 400 may occur in a MulteFire system, for example, between a UE104 and an eNB 120. The UE104 and eNB120 may communicate on one or more communication bands in unlicensed spectrum that may be shared with Wi-Fi stations (e.g., access points) 402.

In an example, the UE104 may be configured to communicate with the scheduled transmission. For example, the eNB120 may transmit a Downlink (DL) burst 404 (e.g., on a PUSCH in the unlicensed spectrum). The DL burst 404 may include an UL grant for a scheduled transmission for the UE. The UE may then perform the scheduled transmission of UL burst 406.

In an example, the UE104 may perform unlicensed UL transmissions (GUL)410 using the PUSCH of the unlicensed spectrum. Prior to performing the gil, the UE104 may perform channel contention (e.g., listen before talk or LBT 408) without an explicit indication from the eNB 120. The LBT may be a type 4 LBT or a single shot (single shot) LBT. After LBT is performed, the UE104 may send data and/or UL control information via the gil 410 on PUSCH. The UL control information may include UE identification (UE id) information, a Modulation and Coding Scheme (MCS) used by the UE, a Redundancy Version (RV), and/or a New Data Indicator (NDI). In response, the eNB120 may transmit Downlink (DL) control information 412, which may include Acknowledgement (ACK)/Negative Acknowledgement (NACK) for the gil 410, UL Channel State Information (CSI), and/or an MCS indication for the UE.

In an example, the eNB may send DL control information 412A after the gil 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 the scheduled DL burst transmission 414 after performing LBT).

Fig. 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. A second UE (UE2) may perform LBT procedure 418 and gil 420, followed by DL control information transmission 422 by the eNB.

In an example, the eNB120 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 an unlicensed uplink transmission on a scheduled transmission.

In an example, the eNB120 may use L1/L2 signaling to control which UEs are allowed to autonomously transmit. More specifically, the eNB120 may transmit 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, L1/L2 signaling may be transmitted on a common physical downlink control channel (cpcpdcch) to all UEs associated with the cell of the eNB. In case that the L1/L2 signaling is sent on the cpccch or as system information, all UEs are informed whether unlicensed uplink transmission is allowed or not. In another example, L1 or L2 signaling may be sent to a particular UE via a Physical Downlink Control Channel (PDCCH) or UE-specific RRC signaling to tell the particular UE whether unlicensed uplink transmissions are allowed. Furthermore, 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 eNB120 may control the possible number of UEs based on various indications from the UEs. In the case where the UE has UL data to send, the UE104 may transmit a Buffer Status Report (BSR) indicating the traffic status at the UE. The eNB120 may then send L1 or L2 signaling to the UE allowing for BSR-based unlicensed uplink transmissions.

In another example, the eNB120 may determine whether the UE needs an unlicensed transmission based on a congestion experience at the UE. In the event that the UE experiences severe congestion at channel access, the eNB may improve the UL transmission opportunity by allowing the UE to make unlicensed uplink transmissions. For example, the congestion status may be based on a rate of UL grant failures. More specifically, in the case where the UE cannot send a scheduled PUSCH transmission for a certain number of UL grants, the eNB may signal the UE to perform an unlicensed uplink transmission. In view of this, unlicensed uplink transmissions may improve UL contention opportunities. In an example, the eNB may signal the UE to perform the unlicensed uplink transmission after the scheduled uplink transmission of the UE fails a particular 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 unlicensed uplink transmissions to avoid coexistence with the scheduled transmission.

Fig. 5 illustrates an example unlicensed UL transmission (gil) within a restricted timing window according to an example embodiment. Referring to fig. 5, communications 500 illustrates how an eNB may restrict operation of unscheduled communications (e.g., unlicensed uplink transmissions) to within a particular known period. More specifically, the eNB may inform the UE to repeat a DTxW period 502A of a Discovery Reference Signal (DRS) transmission window (DTxW) 504. DTxW 504 may be a time interval for transmitting a DRS (e.g., DRS 508). In an example, the paging signal 510 may also be transmitted based on an eNB-initiated paging occasion. DRS 508 may include, for example, Primary Synchronization Signals (PSS), Secondary Synchronization Signals (SSS), system information transmitted on a Physical Broadcast Channel (PBCH), and cell-specific reference signals (CRS). The eNB may inform the UE of the allowed unlicensed transmission interval 506A, which is outside the restricted DTxW 504 (e.g., 504A). In another example, the eNB may indicate the available time domain resources, e.g., in the form of a set of subframes available for the gil. RRC signaling may be used for such indication. A set of subframes available for the gil may be indicated by a bitmap of N bits, and the pattern may repeat every N milliseconds (ms). In one example, N-40.

As shown in fig. 5, 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 transmission 518 during DTxW 504B within DTxW period 502B. The unlicensed uplink transmission 520 may be performed outside of DTxW 504B. In view of this, by limiting the unlicensed uplink transmission to time intervals outside of DTxW, the eNB may minimize the impact of the unlicensed uplink transmission on critical downlink transmissions (e.g., DRS transmissions).

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

In an example, an eNB and/or UE may perceive 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 the unlicensed UL transmission if there are no Wi-Fi stations operating within the unlicensed spectrum within the eNB cell.

Fig. 6A and 6B illustrate example Downlink (DL) transmissions after an unlicensed UL transmission, according to example embodiments.

In a communication environment where scheduled transmissions from the eNB and Wi-Fi stations dominate, the performance of unlicensed UL transmissions may be poor because there is less opportunity to transmit HARQ ACK/NACK feedback, UL CSI, and/or MCS information from the eNB in response to the unlicensed UL transmissions. To increase the transmission opportunity of DL control information, the DL control information may follow the gil and after the eNB performs a single interval LBT. In an example, the eNB does not perform LBT for DL control information if the DL control information is within a Maximum Channel Occupancy Time (MCOT) initialized by a UE associated with the eNB. For example and referring to communication 600A in fig. 6A, 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. Further, downlink control information 614A in response to the unlicensed uplink transmission 608A may be delayed 620A and may be transmitted after the unlicensed uplink transmission 612A. Similarly, downlink control information 616A in response to the unlicensed uplink transmission 612A may be delayed 622A and may be transmitted after the scheduled (or Wi-Fi) transmission, as shown in fig. 6A. In the case where DL control information (e.g., 616A in fig. 6A) is transmitted outside of TxOP, LBT of type 4 is performed for DL control information transmission.

Referring to communication 600B in fig. 6B, an unlicensed uplink transmission 602B may occur before an unlicensed uplink transmission 604B. Downlink control information 606B including ACK/NACK, UL CSI, and/or MCS in response to the unlicensed uplink transmission 602B may occur after the unlicensed uplink transmission 604B. Further, downlink control information 610B in response to the unlicensed uplink transmission 604B may be delayed and may be transmitted after the unlicensed uplink transmission 608B. Similarly, downlink control information 614B in response to the unlicensed uplink transmission 608B may be delayed and may be transmitted during the scheduled DL burst 612B. In these examples, DL control information 606B and 610B may perform a single interval LBT if within MCOT initialized by the UE sending 602B/604B/608B GUL, or may not perform LBT if within, for example, 16us from the end of the previous UL transmission and within MCOT initialized by the UE with a GUL transmission. In the example of DL control information 614B, since the eNB has performed LBT of type 4 for DL burst 612B, LBT or single interval LBT is not performed to transmit DL control information 614B. In the case where DL control information (e.g., 614B) is transmitted outside of a transmission opportunity (TxOP), LBT of type 4 is performed for DL control information transmission.

In an example, to reduce the delay of receiving DL control information from the eNB, the UE may autonomously perform LBT procedures (e.g., type 4 LBT) to request feedback for pending HARQ process procedures (e.g., unacknowledged unlicensed UL transmissions). In addition to the eNB's type 4 LBT contention, the contention may be used to send ACK/NACK feedback. Immediately after the UE performs an unlicensed UL transmission requesting DL control information, the eNB may send HARQ ACK/NACK with very short LBT procedures (or without LBT procedures), as shown by communication 600C in fig. 6C.

Fig. 6C illustrates an example Downlink (DL) transmission after an unlicensed UL transmission requesting an acknowledgement, according to an example embodiment.

Referring to communication 600C in fig. 6C, an unlicensed uplink transmission 608C may occur before an unlicensed uplink transmission 610C. Downlink control information 612C including ACK/NACK, UL CSI, and/or MCS in response to the unlicensed uplink transmission 608 may occur after the unlicensed uplink transmission 610C. Further, downlink control information 616C in response to the unlicensed uplink transmission 610C may be delayed and may be transmitted after the unlicensed uplink transmission 614C. Similarly, downlink control information in response to the 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 of 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). Then, after the unlicensed UL transmission 620C, DL control information 622C is transmitted in response to the unlicensed uplink transmission 614C.

Fig. 7 and 8 are flowcharts illustrating example functions for performing unlicensed uplink transmissions, in accordance with some embodiments. Referring to fig. 7, an example method 700 can begin at 702, when control information received over one or more channels of an unlicensed spectrum can be decoded. The control information may include an indicator that unlicensed Uplink (UL) transmission is allowed without a prior UL grant. For example, eNB120 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 allowed within a particular resource. At 704, a Listen Before Talk (LBT) procedure is performed on one or more channels of the unlicensed spectrum to determine whether there is an available channel in the unlicensed spectrum channels. For example, the UE104 may perform the LBT procedure 408. At 706, upon determining 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 unlicensed UL transmissions. For example, the GUL 410 may be performed by the UE without a prior UL grant by the eNB. In view of this, the unlicensed uplink transmission 410 is an unscheduled unlicensed transmission that is performed on an available channel of the unlicensed spectrum without an UL grant.

Referring to fig. 8, an example methodology 800 can begin at 802 when control information can be encoded for transmission over one or more channels of an unlicensed spectrum. For example, eNB120 may encode physical layer or higher layer signaling (e.g., DCI or RRC signaling) that may include an indication that unlicensed Uplink (UL) transmission is allowed without a prior UL grant within a particular resource. At 804, the UL control information and data may be decoded. The control information and data may be received on sPUCCH/ePUCCH and/or a Physical Uplink Shared Channel (PUSCH) using unlicensed UL transmissions. For example, control information and data may be received from a UE via an unlicensed uplink transmission, where the unlicensed uplink transmission is an unscheduled unlicensed transmission that is performed on one or more channels of an unlicensed spectrum without an 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, including ACK/NACK indications, UL CSI, and/or MCS information.

Fig. 9 illustrates a block diagram of a communication device (e.g., an eNB or UE) in accordance with some embodiments. In alternative embodiments, the communication device 900 may operate as a standalone device or may be connected (e.g., networked) to other communication devices. In a networked deployment, the communication device 900 may operate in the capacity of a server communication device, a client communication device, or both, in a server-client network environment. In an example, the communications device 900 can operate as a peer to peer communications device in a peer to peer (P2P) (or other distributed) network environment. The communication device 900 may be a UE, eNB, PC, tablet PC, STB, PDA, mobile phone, smartphone, network equipment, network router, switch or bridge, or any communication device capable of executing instructions (sequential or otherwise) that specify actions to be taken by the communication device. Further, while only a single communication device is shown, the term "communication device" shall also be taken to include any collection of communication devices that individually or jointly execute a set (or multiple sets) of instructions to implement any one or more of the methodologies discussed herein, such as cloud computing, software as a service (SaaS), or other computer cluster configurations.

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

Thus, the term "module" is understood to include a tangible entity, i.e., an entity that is physically constructed, specifically configured (e.g., hardwired), or temporarily (e.g., programmed) to operate in a specified manner or to perform some or all of any of the operations described herein. Considering the example of modules being temporarily configured, each module need not be instantiated at any time. For example, where the modules include a general purpose hardware processor configured using software, the general purpose hardware processor may be configured as respective different modules at different times. The software may configure the hardware processor accordingly, e.g., to constitute 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 through an interconnect (e.g., 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., drive unit) 916, a signal generation 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, compass, accelerometer, or other sensor). The communication device 900 may include an output controller 928, such as a serial (e.g., Universal Serial Bus (USB)), parallel, or other wired or wireless (e.g., Infrared (IR), Near Field Communication (NFC), etc.) connection to communicate with or control one or more peripheral devices (e.g., a printer, 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 embodied or used by any one or more of the techniques or functions described herein. The instructions 924 may also reside, partially or wholly, within the main memory 904, within the static memory 906, or within the hardware processor 902 during execution thereof by the communication device 900. In an example, one or any combination of the hardware processor 902, the main memory 904, the static memory 906, or the storage device 916 may constitute communication device readable media.

While the communication device-readable medium 922 is shown to be a single medium, the term "communication device-readable medium" can include a single medium or multiple media (e.g., a centralized or distributed database, and/or associated caches and servers) configured to store the one or more instructions 924.

The term "communication device-readable medium" can include any medium that can store, encode, or carry instructions for execution by communication device 900 and that cause communication device 900 to perform any one or more of the techniques of this disclosure, or that can store, encode, or carry data structures used by or associated with such instructions. Non-limiting examples of communication device readable media may include solid state memory, and optical and magnetic media. Specific examples of the communication device-readable medium may include non-volatile memories such as semiconductor memory devices (e.g., electrically programmable read-only memories (EPROMs), electrically erasable programmable read-only memories (EEPROMs)) 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 a non-transitory communication device readable medium. In some examples, the communication device readable medium may include a communication device readable medium that is not a transitory propagating signal.

The instructions 924 may also be through a communications network using a transmission medium926, which are transmitted or received via the network interface device 920 utilizing a plurality of transport 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 telephone network (e.g., a cellular network), a Plain Old Telephone (POTS) network, a wireless data network (e.g., known as a cellular network)

Known as the Institute of Electrical and Electronics Engineers (IEEE)802.11 series of standards

IEEE 802.16 series of standards), IEEE 802.15.4 series of standards, Long Term Evolution (LTE) series of standards, Universal Mobile Telecommunications System (UMTS) series of standards, peer-to-peer (P2P) networks, and so forth. 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 wirelessly communicate using at least one of single-input multiple-output (SIMO), multiple-input multiple-output (MIMO), or multiple-input single-output (MISO) techniques. In some examples, the network interface device 920 may wirelessly communicate using multi-user MIMO techniques. The term "transmission medium" shall be taken to include any intangible medium that is capable of storing, encoding, or carrying instructions for execution by the communication device 900, and includes digital or analog communications signals or other intangible medium to facilitate communication of such software.

Additional description and examples:

example 1 is an apparatus of a User Equipment (UE), the apparatus comprising: a memory; and processing circuitry configured to: decoding control information received on one or more channels of an unlicensed spectrum, the control information including an indication that unlicensed Uplink (UL) transmissions (GULs) are allowed without a prior UL grant; performing a Listen Before Talk (LBT) procedure on one or more channels of the unlicensed spectrum to determine whether there is an available channel in the channels; and when it is determined that the channel is available, encoding UL control information and data for transmission using an unlicensed UL transmission, wherein the unlicensed uplink transmission is an unscheduled transmission performed on the channel of the unlicensed spectrum without a UL grant.

In example 2, the subject matter of example 1 optionally includes: wherein the control information is Downlink Control Information (DCI) received on a common physical downlink control channel (cpccch) within the unlicensed spectrum.

In example 3, the subject matter of any one or more of examples 1-2 optionally includes: wherein the memory stores UL control information and data for transmission using the unlicensed UL transmission.

In example 4, the subject matter of any one or more of examples 1-3 optionally includes: wherein the control information is Radio Resource Control (RRC) information received on a Physical Downlink Shared Channel (PDSCH) within the unlicensed spectrum.

In example 5, the subject matter of any one or more of examples 1-4 optionally includes: wherein the UL control information comprises at least one of: a UE identification (UEID) of the UE; modulation 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 a data transmission; a length of a UL burst transmitting 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 optionally includes: wherein the processing circuitry is configured to: encoding a Buffer Status Report (BSR) for transmission to an evolved node B (eNB), the BSR indicating transmission congestion for scheduled UL transmissions of the UE.

In example 7, the subject matter of example 6 optionally includes: wherein control information including an indicator that unlicensed UL transmission is allowed is 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 circuitry is configured to: monitoring a common physical downlink control channel (cpcpdcch) within an unlicensed spectrum for scheduled transmissions; and detecting a presence of burst information for a scheduled Downlink (DL) transmission and/or a scheduled UL transmission in an unlicensed spectrum by an evolved node b (enb) indicated by the cpcpdcch.

In example 9, the subject matter of example 8 can optionally include: wherein the processing circuitry is configured to: deferring an unlicensed uplink transmission to avoid coexistence with a scheduled DL transmission and/or a scheduled UL transmission.

In example 10, the subject matter of any one or more of examples 1-9 optionally includes: wherein the processing circuitry is configured to: decoding second Downlink (DL) control information received on one or more channels of the unlicensed spectrum, the second DL control information including Acknowledgement (ACK)/Negative Acknowledgement (NACK) signaling in response to the unlicensed uplink transmission.

In example 11, the subject matter of any one or more of examples 9-10 optionally includes: 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 optionally includes: wherein the processing circuitry is configured to: decoding signaling indicating periodicity of DRS transmissions within the DTxW; and restricting the unlicensed UL transmissions to time intervals other than DTxW.

In example 13, the subject matter of any one or more of examples 1-12 optionally includes: wherein the processing circuitry is configured to: decoding an indication of available time domain resources available for unlicensed UL transmissions.

In example 14, the subject matter of any one or more of examples 1-13 optionally includes: wherein the available time domain resources comprise a set of available subframes, and wherein the indication is a bitmap of N bits, the pattern of N bits repeating every N ms.

In example 15, the subject matter of any one or more of examples 1-14 optionally includes: wherein the control information comprises an indication of a maximum UL transmission duration and the processing circuitry is configured to: the duration of the unlicensed UL transmission is limited to within a maximum UL transmission duration.

Example 16 is an apparatus of an evolved node b (enb), the apparatus comprising: a memory; and processing circuitry configured to: encoding control information for transmission on one or more channels of an unlicensed spectrum, the control information including an indication that unlicensed Uplink (UL) transmissions are allowed without a preceding UL grant; decoding UL control information and data received using unlicensed UL transmissions, wherein the unlicensed uplink transmissions are unscheduled transmissions performed on one or more channels of an unlicensed spectrum; and encoding Acknowledgement (ACK) feedback or Negative Acknowledgement (NACK) feedback in response to the unlicensed uplink transmission.

In example 17, the subject matter of example 16 optionally includes: wherein the processing circuitry is configured to: encoding a UL grant for transmission to the UE, the UL grant being associated with the scheduled UL transmission; and detecting a number of failures of the scheduled UL transmission.

In example 18, the subject matter of any one or more of examples 16-17 optionally includes: wherein the memory stores control information for transmission over one or more channels of the unlicensed spectrum.

In example 19, the subject matter of any one or more of examples 17-18 optionally includes: wherein the processing circuitry is configured to: encoding control information indicating that unlicensed 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 to encode the control information, the processing circuit is configured to: encoding Downlink Control Information (DCI) including an indicator that unlicensed UL transmissions are allowed to be transmitted on a common physical downlink control channel (cPDCCH) within the unlicensed spectrum.

In example 21, the subject matter of any one or more of examples 16-20 optionally includes: wherein to encode the control information, the processing circuit is configured to: radio Resource Control (RRC) information is encoded, the RRC information including an indicator that unlicensed UL transmissions are allowed 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 circuitry is configured to: decoding a Buffer Status Report (BSR) from a User Equipment (UE), the BSR indicating transmission congestion for a scheduled UL transmission of the UE.

In example 23, the subject matter of example 22 optionally includes: wherein the processing circuitry is configured to: control information having an indication that unlicensed UL transmissions are allowed to be transmitted on one or more channels of an unlicensed spectrum in response to a BSR is encoded.

In example 24, the subject matter of any one or more of examples 22-23 optionally includes: wherein the processing circuitry is configured to: decoding a second unlicensed UL transmission, the second unlicensed UL transmission including a request for acknowledgement of the unlicensed UL transmission.

In example 25, the subject matter of example 24 can optionally include: wherein the processing circuitry is configured to: in response to the second unlicensed UL transmission, second Acknowledgement (ACK)/Negative Acknowledgement (NACK) feedback in response to the unlicensed uplink transmission is encoded.

Example 26 is a computer-readable storage medium storing instructions for execution by one or more processors of a User Equipment (UE), the one or more processors to configure the UE to: decoding an indication of a Discovery Reference Signal (DRS) transmission window (DTxW) period, the DTxW period indicating a periodicity of DRS transmissions within the DTxW; decoding control information received on one or more channels of an unlicensed spectrum, the control information including an indication that unlicensed Uplink (UL) transmissions are allowed without a prior UL grant; performing a Listen Before Talk (LBT) procedure on one or more channels of an unlicensed spectrum; and transmitting the 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 UL transmissions are performed in a time interval outside of DTxW without UL grants.

In example 27, the subject matter of example 26 can optionally include: wherein the one or more processors further configure the UE to: monitoring a common physical downlink control channel (cpcpdcch) within an unlicensed spectrum for scheduled transmissions; and detecting a presence of burst information for a scheduled Downlink (DL) transmission and/or a scheduled UL transmission in an unlicensed spectrum by an evolved node b (enb) indicated by the cpcpdcch.

In example 28, the subject matter of example 27 optionally includes: wherein the one or more processors further configure the UE to: deferring an unlicensed uplink transmission to avoid coexistence with a scheduled DL transmission and/or a scheduled UL transmission 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: second control information is received on one or more channels of the unlicensed spectrum, the second control information including Acknowledgement (ACK)/Negative Acknowledgement (NACK) feedback in response to the unlicensed uplink transmission.

In example 30, the subject matter of example 29 optionally comprising: 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 optionally includes: wherein the one or more processors further configure the UE to: detecting a failure to receive first Acknowledgement (ACK)/Negative Acknowledgement (NACK) signaling in response to an unlicensed uplink transmission.

In example 32, the subject matter of example 31 can optionally include: wherein the one or more processors further configure the UE to: in response to a detection failure, encoding a request for acknowledgement of an unlicensed UL transmission; a request for acknowledgement is sent using a second unlicensed UL transmission.

In example 33, the subject matter of example 32 can optionally include: wherein the processing circuitry is configured to: decoding second Acknowledgement (ACK)/Negative Acknowledgement (NACK) feedback associated with the unlicensed uplink transmission, the second ACK/NACK signaling received in response to the second unlicensed UL transmission.

Example 34 is an apparatus of a User Equipment (UE), the apparatus comprising means for decoding an indication of a Discovery Reference Signal (DRS) transmission window (DTxW) period, the DTxW period indicating a periodicity of DRS transmissions within the DTxW; means for decoding control information received on one or more channels of an unlicensed spectrum, the control information including an indication that unlicensed Uplink (UL) transmissions are allowed without a prior UL grant; means for performing a Listen Before Talk (LBT) procedure on one or more channels of an unlicensed spectrum; and means for transmitting the 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 UL transmissions are performed in a time interval outside of DTxW without UL grants.

In example 35, the subject matter of example 34 can optionally include: means for monitoring a common physical downlink control channel (cPPDCCH) within an unlicensed spectrum for scheduled transmissions; and means for detecting a presence of burst information for a scheduled Downlink (DL) transmission and/or a scheduled UL transmission in an unlicensed spectrum by an evolved node b (enb) indicated by the cpcpdcch.

In example 36, the subject matter of example 35 optionally includes: means for deferring an unlicensed uplink transmission to avoid coexistence with a scheduled DL transmission and/or a scheduled UL transmission scheduled by an associated eNB.

In example 37, the subject matter of any one or more of examples 35-36 optionally includes: means for receiving second control information on one or more channels of an unlicensed spectrum, the second control information including Acknowledgement (ACK)/Negative Acknowledgement (NACK) feedback in response to an unlicensed uplink transmission.

In example 38, the subject matter of example 37 optionally includes: wherein the second control information is received during a Maximum Channel Occupancy Time (MCOT) reserved by the UE during the LBT procedure.

In example 39, the subject matter of any one or more of examples 34-38 optionally includes: means for detecting a failure to receive first Acknowledgement (ACK)/Negative Acknowledgement (NACK) signaling in response to an unlicensed uplink transmission.

In example 40, the subject matter of example 39 optionally includes: means for encoding a request for acknowledgement of an unlicensed UL transmission in response to detecting the failure; means for transmitting a request for acknowledgement using a second unlicensed UL transmission.

In example 41, the subject matter of example 40 optionally includes: means for decoding second Acknowledgement (ACK)/Negative Acknowledgement (NACK) feedback associated with the unlicensed uplink transmission, the second ACK/NACK signaling received in response to the second unlicensed UL transmission.

The publications, patents, and patent documents referred to in this document are incorporated by reference herein in their entirety as if individually incorporated by reference. In the event of inconsistent usages between this document and those documents so incorporated by reference, the usage in the incorporated cited document(s) is complementary to the usage in this document; for completely incompatible inconsistencies, the usage in this document is followed.

The above description is intended to be illustrative, and not restrictive. For example, the above-described examples (and one or more aspects thereof) may be used in conjunction with other examples. For example, other embodiments may be used by those skilled in the art in view of the above description. The abstract is provided to enable the reader to quickly ascertain the nature of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims. Furthermore, in the foregoing detailed description, various features may be combined together to form the disclosure. However, the claims may not reveal every feature disclosed herein because embodiments may embody a subset of the features. Moreover, embodiments may include fewer features than those disclosed in the particular examples. Thus, the following claims are hereby incorporated into the detailed description, with the claims standing on their own as separate embodiments. The scope of the embodiments disclosed herein should be determined with reference to the appended claims, along with the full scope of equivalents to which such claims are entitled.

Claims (25)

1. An apparatus for use in a user equipment, UE, the apparatus comprising:

a memory; and processing circuitry configured to cause the UE to:

receiving control information received on one or more channels of an unlicensed spectrum, the control information including an indication that autonomous UL transmissions are allowed without a prior uplink UL grant;

performing a listen before talk, LBT, procedure on the one or more channels of the unlicensed spectrum to determine whether there is an available channel in the channels; and

transmitting UL control information and data for transmission using the autonomous UL transmission when the channel is determined to be available, wherein the autonomous uplink transmission is an unscheduled transmission performed on the channel of the unlicensed spectrum without a UL grant.

2. The apparatus of claim 1, wherein the control information is downlink control information, DCI, received on a common physical downlink control channel, cpccch, within 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 a Physical Downlink Shared Channel (PDSCH) within the unlicensed spectrum.

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

a UE identification (UEID) of the UE;

a modulation coding scheme, MCS, used by the UE;

the UE is used for transmitting data by a redundancy version RV;

a New Data Indicator (NDI) associated with the data transmission;

a length of a UL burst transmitting the UL control information; and

the maximum channel occupancy time MCOT reserved by the performed LBT.

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

encoding a Buffer Status Report (BSR) for transmission to an evolved node B, the BSR indicating transmission congestion for scheduled UL transmissions of the UE.

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

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

monitoring a common physical downlink control channel, cpcch, within the unlicensed spectrum for scheduled transmissions; and

detecting a presence of burst information for an evolved node B scheduled Downlink (DL) transmission and/or a scheduled UL transmission in the unlicensed spectrum indicated by the cPDCCH.

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

defer the autonomous uplink transmission from concurrent with the scheduled DL transmission and/or the scheduled UL transmission.

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

decoding second downlink, DL, control information received on the one or more channels of the unlicensed spectrum, the second DL control information comprising acknowledgement, ACK, or negative acknowledgement, NACK, signaling in response to the autonomous uplink transmission.

11. The apparatus of claim 10, wherein the second DL control information is received during a maximum channel occupancy time, MCOT, reserved by the UE during the LBT procedure.

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

decoding signaling indicating periodicity of DRS transmissions within the DTxW; and

limiting the autonomous UL transmission to a time interval outside the DTxW.

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

decoding an indication of available time domain resources available 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 every N ms.

15. The apparatus of claim 1, wherein the control information comprises an indication of a maximum UL transmission duration, and the processing circuitry is configured to:

limiting a duration of the autonomous UL transmission to within the maximum UL transmission duration.

16. An apparatus for use in an evolved node B, the apparatus comprising:

a memory; and processing circuitry configured to cause the evolved node B to:

transmitting control information for transmission on one or more channels of an unlicensed spectrum, the control information including an indication that autonomous UL transmissions are allowed without a prior uplink UL grant;

receiving UL control information and data received using the autonomous UL transmission, wherein the autonomous uplink transmission is an unscheduled transmission performed on the one or more channels of the unlicensed spectrum without a UL grant; and

transmitting Acknowledgement (ACK) feedback or Negative Acknowledgement (NACK) feedback in response to the autonomous uplink transmission.

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

encoding a UL grant for transmission to a User Equipment (UE), the UL grant associated with a scheduled UL transmission; and

detecting a number of failures of the scheduled UL transmission.

18. An apparatus for use in communication, the apparatus comprising:

means for decoding an indication of a discovery reference signal, DRS, transmission window, DTxW, period, the DTxW period indicating a periodicity of DRS transmissions within the DTxW;

means for decoding control information received on one or more channels of an unlicensed spectrum, the control information including an indication that autonomous UL transmissions are allowed without a prior uplink UL grant;

means for performing a Listen Before Talk (LBT) procedure on the one or more channels of the unlicensed spectrum; and

means for transmitting the 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 the autonomous UL transmission, wherein the autonomous uplink transmission is performed in a time interval outside the DTxW without a UL grant.

19. The apparatus of claim 18, further comprising:

means for monitoring a common physical downlink control channel, cPPDCCH, within the unlicensed spectrum for scheduled transmissions; and

means for detecting a presence of burst information for an evolved node B scheduled Downlink (DL) transmission and/or a scheduled UL transmission in the unlicensed spectrum indicated by the cPDCCH.

20. The apparatus of claim 19, further comprising:

means for deferring the autonomous uplink transmission to avoid coexistence with a scheduled DL transmission and/or a scheduled UL transmission scheduled by an associated evolved node B.

21. The apparatus of claim 19, further comprising:

means for receiving second control information on the one or more channels of the unlicensed spectrum, the second control information comprising Acknowledgement (ACK)/Negative Acknowledgement (NACK) feedback in response to the autonomous uplink transmission.

22. The apparatus of claim 21, wherein the second control information is received during a Maximum Channel Occupancy Time (MCOT) reserved by a UE during the LBT procedure.

23. The apparatus of claim 18, further comprising:

means for detecting a failure to receive first acknowledgement, ACK/negative acknowledgement, NACK, signaling in response to the autonomous uplink transmission.

24. The apparatus of claim 23, further comprising:

means for encoding a request for acknowledgement of the autonomous UL transmission in response to detecting the failure; and

means for transmitting the request for acknowledgement of the autonomous UL transmission using a second autonomous UL transmission.

25. The apparatus of claim 24, further comprising:

means for decoding a second acknowledgement, ACK/negative acknowledgement, NACK feedback associated with the autonomous uplink transmission, the second ACK/NACK signaling received in response to the second autonomous UL transmission.

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