Patent Description:
The use of unlicensed spectrum in the Third Generation Partnership Project (3GPP) Long Term Evolution-Advanced (LTE-A) system has been proposed as Licensed Assisted Access (LAA). Under LAA, the LTE standard is extended into unlicensed frequency deployments, thus enabling operators and vendors to maximally leverage the existing or planned investments in LTE hardware in the radio and core network.

One concern with LAA is the co-existence of the LTE radio nodes and other radio access technologies (RATs), such as WiFi and/or other LAA networks deployed by other operators using other unlicensed radio nodes. To enable the co-existence of the LTE radio nodes and other unlicensed nodes, listen-before-talk (LBT) (also called Clear Channel Assessment (CCA)) has been proposed. LBT is a contention protocol in which the LTE radio node determines whether a particular frequency channel is already occupied (e.g., by a WiFi node) before using the particular frequency channel. That is, with LBT, data packets may only be transmitted when a channel is sensed to be idle.

<NPL> disloses evaluating Licensed Assisted Access Listen-Before-Talk energy detection thresholds according to indoor and outdoor scenarios.

To facilitate this description, like reference numerals may designate like structural elements.

The following detailed description refers to the accompanying drawings. It is to be understood that other embodiments may be utilized and structural or logical changes may be made without departing from the scope of the present disclosure. Therefore, the following detailed description is not to be taken in a limiting sense, and the scope of embodiments in accordance with the present disclosure is defined by the appended claims.

Existing WiFi (i.e., Institute of Electrical and Electronics Engineers (IEEE) <NUM>-based wireless networking standards) technologies, to enable the co-existence of multiple WiFi Access Points (APs), may use the Carrier Sense Multiple Access with Collision Avoidance (CSMA/CA) technique to enable co-existence between multiple WiFi nodes. Under CSMA/CA, when a WiFi transmitter (e.g., a WiFi access point (AP)) detects a WiFi preamble of another WiFi transmitter, with a received energy level of at-least -<NUM> dBm (decibel-milliwatts), the WiFi transmitter is required to defer its transmission based on a duration included in the detected preamble (physical carrier sensing). In some situations, the WiFi transmitter may not be able to detect the WiFi preamble. For instance, an LTE-LAA node may use the same frequency band as the WiFi transmitter. In this situation, the WiFi transmitter may use a -<NUM> dBm threshold to determine when to defer its transmission. The WiFi transmitter may defer transmission at least until the detected energy level is below -<NUM> dBm. In this manner, existing WiFi implementations may use a predetermined energy detection (ED) thresholds (e.g., -<NUM> dBm and -<NUM> dBm) when determining whether a channel is "clear" for transmission.

ED thresholds may be used by LTE-LAA nodes during the LBT contention protocol to sense other LTE-LAA nodes as well as non LTE-LAA nodes (e.g., WiFi transmitters). In particular, under LAA, an LTE-LAA node may defer its transmission at least until the energy received by is less than a certain ED threshold. However, using predetermined ED thresholds, for LTE-LAA nodes, may be problematic for good co-existence between the LTE-LAA nodes and between transmitters of other RATs (e.g., WiFi transmitters). For example, WiFi throughput, in certain scenarios such as in indoor operation, can be significantly degraded in the presence of LTE-LAA nodes using a -<NUM> dBm ED threshold. A conservative ED threshold of -<NUM> dBm may enable good co-existence between WiFi and LAA in indoor scenarios. In other scenarios, however, such as an outdoor scenario, the use of-<NUM> dBm as the ED threshold can enable good co-existence between WiFi and LAA.

Consistent with aspects described herein, when performing a contention protocol, such as LBT, an LTE-LAA node may dynamically adapt the ED threshold used by the LTE-LAA node depending on whether other transmission nodes are detected at the frequency components that are to be used by the LTE-LAA node. In one implementation, the ED threshold value may initially be set to a conservative value, and when other transmissions nodes are not detected, the ED threshold value may be set to a more aggressive value. In another implementation, the ED threshold value may initially be set to a more aggressive value, and only when another transmission node is detected, the ED threshold value may be set to a more conservative value. In yet another possible implementation, the ED threshold value and the transmit power may be proportionally modified, for a particular UE, based on a parameter associated with the UE.

<FIG> is a diagram of an example environment <NUM>, in which systems and/or methods described herein may be implemented. As illustrated, environment <NUM> may include User Equipment (UE) <NUM>, which may obtain network connectivity from wireless network <NUM>. Although a single UE <NUM> is shown, for simplicity, in <FIG>, in practice, multiple UEs <NUM> may operate in the context of a wireless network. Wireless network <NUM> may provide access to one or more external networks, such as packet data network (PDN) <NUM>. The wireless network may include radio access network (RAN) <NUM> and core network <NUM>. RAN <NUM> may be a E-UTRA based radio access network or another type of radio access network. Some or all of RAN <NUM> may be associated with a network operator that controls or otherwise manages core network <NUM>. Core network <NUM> may include an Internet Protocol (IP)-based network.

UE <NUM> may include a portable computing and communication device, such as a personal digital assistant (PDA), a smart phone, a cellular phone, a laptop computer with connectivity to a cellular wireless network, a tablet computer, etc. UE <NUM> may also include non-portable computing devices, such as desktop computers, consumer or business appliances, or other devices that have the ability to wirelessly connect to RAN <NUM>.

UEs <NUM> may be designed to operate using LTE-LAA. For instance, UEs <NUM> may include radio circuitry that is capable of simultaneously receiving multiple carriers: a first, primary, carrier using licensed spectrum and a second carrier using unlicensed spectrum. The second carrier may correspond to, for example, the unlicensed <NUM> spectrum. This spectrum may commonly be used by WiFi devices. A goal of LTE-LAA may be to not impact WiFi services more than an additional WiFi network on the same carrier.

UEs <NUM> capable of operating on the unlicensed band may be configured to make measurements to support unlicensed band operation, including providing feedback when the UE is in the coverage area of an LTE-LAA node. Once the connection is activated to allow use on the unlicensed band, existing Channel Quality Information (CQI) feedback may allow the evolved NodeBs (eNBs) <NUM> to determine what kind of quality could be achieved on the unlicensed band compared to the licensed band. Downlink only mode is particularly suited for situations where data volumes are dominated by downlink traffic.

RAN <NUM> may represent a 3GPP access network that includes one or more RATs. RAN <NUM> may particularly include multiple base stations, referred to as eNBs <NUM>. eNBs <NUM> may include eNBs that provide coverage to a relatively large (macro cell) area or a relatively small (small cell) area. Small cells may be deployed to increase system capacity by including a coverage area within a macro cell. Small cells may include picocells, femtocells, and/or home NodeBs. eNBs <NUM> can potentially include remote radio heads (RRH), such as RRHs <NUM>. RRHs <NUM> can extend the coverage of an eNB by distributing the antenna system of the eNB. RRHs <NUM> may be connected to eNB <NUM> by optical fiber (or by another low-latency connection).

In the discussion herein, an LTE-LAA node may correspond to eNB <NUM> (small cell or macro cell) or RRH <NUM>. The LTE-LAA node may also be referred to as an "LTE-LAA transmission point," "LTE-LAA transmitter," or "LAA eNB. " For simplicity, eNB <NUM> will be discussed herein as corresponding to an LTE-LAA node. In some implementations, the LTE-LAA node (using unlicensed frequency) may be co-located with a corresponding eNB that uses licensed frequency. The licensed frequency eNBs and the LTE-LAA node may maximize downlink bandwidth by performing carrier aggregation of the licensed and unlicensed bands.

Core network <NUM> may include an IP-based network. In the 3GPP network architecture, core network <NUM> may include an Evolved Packet Core (EPC). As illustrated, core network <NUM> may include serving gateway (SGW) <NUM>, Mobility Management Entity (MME) <NUM>, and packet data network gateway (PGW) <NUM>. Although certain network devices are illustrated in environment <NUM> as being part of RAN <NUM> and core network <NUM>, whether a network device is labeled as being in the "RAN" or the "core network" of environment <NUM> may be an arbitrary decision that may not affect the operation of wireless network <NUM>.

SGW <NUM> may include one or more network devices that aggregate traffic received from one or more eNBs <NUM>. SGW <NUM> may generally handle user (data) plane traffic. MME <NUM> may include one or more computation and communication devices that perform operations to register UE <NUM> with core network <NUM>, establish bearer channels associated with a session with UE <NUM>, hand off UE <NUM> from one eNB to another, and/or perform other operations. MME <NUM> may generally handle control plane traffic.

PGW <NUM> may include one or more devices that act as the point of interconnect between core network <NUM> and external IP networks, such as PDN <NUM>, and/or operator IP services. PGW <NUM> may route packets to and from the access networks, and the external IP networks.

PDN <NUM> may include one or more packet-based networks. PDN <NUM> may include one or more external networks, such as a public network (e.g., the Internet) or proprietary networks that provide services that are provided by the operator of core network <NUM> (e.g., IP multimedia (IMS)-based services, transparent end-to-end packet-switched streaming services (PSSs), or other services).

A number of interfaces are illustrated in <FIG>. An interface may refer to a physical or logical connection between devices in environment <NUM>. The illustrated interfaces may be 3GPP standardized interfaces. For example, as illustrated, communication eNBs <NUM> may communicate with SGW <NUM> and MME <NUM> using the S1 interface (e.g., as defined by the 3GPP standards). eNBs <NUM> may communicate with one another via the X2 interface.

The quantity of devices and/or networks, illustrated in <FIG>, is provided for explanatory purposes only. In practice, there may be additional devices and/or networks; fewer devices and/or networks; different devices and/or networks; or differently arranged devices and/or networks than illustrated in <FIG>. Alternatively, or additionally, one or more of the devices of environment <NUM> may perform one or more functions described as being performed by another one or more of the devices of environment <NUM>. Furthermore, while "direct" connections are shown in <FIG>, these connections should be interpreted as logical communication pathways, and in practice, one or more intervening devices (e.g., routers, gateways, modems, switches, hubs, etc.) may be present.

<FIG> is a flowchart illustrating a process <NUM> that provides an overview of LBT. Process <NUM> may be performed by, for example, eNB <NUM> (i.e., by an eNB that acts as an LTE-LAA node).

Process <NUM> may include assembling data that is to be transmitted (block <NUM>). The data may be assembled, for example, as a packet or as another data structure (e.g., a frame), by eNB <NUM>, and for transmission to UE <NUM>.

Process <NUM> may further include determining whether the channel, for which the data is to be transmitted, is idle (block <NUM>). The determination of whether a particular frequency channel is idle may include measuring the energy associated with the channel and comparing the measured energy value to a threshold. In some implementations, the threshold may be dynamically or semi-statically selected. For example, depending on the deployment situation, the threshold value may be selected between -<NUM> dBm and -<NUM> dBm. In some implementations, the determination of whether the channel is idle may additionally involve physical carrier sensing to read information transmitted in the frequency channel. For example, for a WiFi transmission, the WiFi preamble or beacon may be read to obtain information.

When the channel is determined to not be idle (block <NUM> - No), the eNB may perform a back-off procedure (block <NUM>). The back-off procedure may include waiting a predetermined amount of time before attempting to use the channel again, waiting a random amount of time before attempting to use the channel again, or waiting an amount of time that is determined from another source (e.g., a WiFi preamble). In some implementations, the back-off procedure may potentially include the selection of different frequency channel.

When the channel is determined to be idle (block <NUM> - No), the assembled data may be transmitted on the channel (block <NUM>). In this manner, LTE-LAA deployments may co-exist with other RATs or with LTE-LAA deployments from other network operators.

<FIG> is a flowchart illustrating an example process <NUM> that illustrates one example embodiment for performing LBT using ED threshold adaptation for LTE-LAA. Process <NUM> may be performed by UE <NUM> or by eNB <NUM> (i.e., by an eNB that acts as an LTE-LAA node).

Process <NUM> may include initially setting the ED threshold to a conservative value (block <NUM>). In one implementation, the conservative ED threshold may be set at a value of -<NUM> dBm. Alternatively, the conservative ED threshold may be set at a value of -<NUM> dBm. More generally, the conservative value may be at the lower half of the range of potential ED threshold values. For example, if the range of potential ED threshold values is between -<NUM> dBm and -<NUM> dBm, a conservative ED threshold value may be between -<NUM> dBm and -<NUM> dBm for an eNB operating on <NUM> channel bandwidth.

Process <NUM> may further include determining whether other transmission nodes are detected at the frequency components corresponding to the LAA carrier (block <NUM>). In one implementation, whether other transmission nodes are detected at the frequency components corresponding to the LAA carrier may include determining whether a nearby WiFi transmitter (e.g., a WiFi AP) is present. The determination may potentially be made by eNB <NUM>, UE <NUM>, or both eNB <NUM> and UE <NUM>. Example implementations for the detection of a nearby WiFi transmitter will be described in more detail below.

In some implementations, the detected other transmission nodes of block <NUM> may include other LTE-LAA nodes, such as other LTE-LAA nodes associated with other network operators (i.e., with a network operator different than the network operator that manages RAN <NUM>).

When another transmission node is not detected (block <NUM> - No), process <NUM> may further include setting the ED threshold to a more aggressive value. In one implementation, the more aggressive ED threshold may be set to a value of -<NUM> dBm. With a more aggressive value, LBT back-off is less likely to be performed. More generally, the aggressive may be at the upper half of the range of potential ED threshold values. For example, if the range of potential ED threshold values is between -<NUM> dBm and -<NUM> dBm, an aggressive ED threshold value may be between -<NUM> dBm and -<NUM> dBm.

Process <NUM> may further include performing the LBT operation using the set ED threshold value (block <NUM>). As shown in <FIG>, the set ED threshold value may be the conservative value when another transmission node is detected (block <NUM> - Yes) or the more aggressive value when another transmission node is not detected (block <NUM> - No). The LBT operation may be performed pursuant to process <NUM> (<FIG>). For example, the LBT operation may include the operations associated with block <NUM> and <NUM> of process <NUM>, or, alternatively or additionally, the LBT operation may include the operations associated with blocks <NUM>-<NUM> of process <NUM>.

<FIG> is a flowchart illustrating an example process <NUM> that illustrates a second example embodiment for performing LBT using ED threshold adaptation for LTE-LAA. Process <NUM> may be performed by UE <NUM> or by eNB <NUM> (i.e., by an eNB that acts as an LTE-LAA node).

Process <NUM> may include initially setting the ED threshold to a relatively aggressive value (block <NUM>). In one implementation, the aggressive ED threshold may be set at a value of -<NUM> dBm.

Process <NUM> may further include determining whether other transmission nodes are detected at the frequency components corresponding to the LAA carrier (block <NUM>). In one implementation, whether other transmission nodes are detected at the frequency components corresponding to the LAA carrier may include determining whether a nearby WiFi transmitter (e.g., a WiFi AP) is present. The determination may potentially be made by eNB <NUM>, UE <NUM>, or both eNB <NUM> and UE <NUM>. Example implementations for the detection of a nearby WiFi transmitter are described in more detail below.

When another transmission node is detected (block <NUM> - Yes), process <NUM> may further include setting the ED threshold to a more conservative value. In one implementation, the more conservative ED threshold may be set to a value of -<NUM> dBm. Alternatively, the more conservative ED threshold may be set to a value of -<NUM> dBm. With the more conservative ED value, LBT back-off is more likely to be performed.

In processes <NUM> and <NUM>, detection of another frequency node, such as a WiFi transmission node, is performed (e.g., blocks <NUM> and <NUM>). A number of different techniques may be used to detect the presence of a WiFi transmission node, some of which will next be discussed.

In one possible implementation for detecting the presence of a WiFi transmission node, eNB <NUM> may detect the presence of WiFi beacon frames. A beacon frame is one of the management frames in IEEE <NUM> based Wireless Local Area Networks (WLANs). Beacon frames may be transmitted periodically to announce the presence of a WiFi LAN. To detect the presence of a WiFi transmission point, eNB <NUM> may detect the presence of beacon frames with a signal strength that is greater than the ED threshold value (e.g., -<NUM> dBm).

In a second possible implementation for detecting the presence of a nearby WiFi transmission node, WLAN measurements may be obtained by UE <NUM>. The WLAN measurements may be reported, by UE <NUM>, to eNB <NUM>. For example, UE <NUM> may report the measurements via licensed frequency channels. In one implementation, the UE <NUM> may report the Received Signal Strength Indicator (RSSI) associated with WiFi beacons, Basic Service Set Identifier (BSSIDs) included in the WiFi beacons, and/or other metrics obtained from the beacons, such as WiFi channel utilization, WiFi transmission bandwidth, etc. In this manner, UE <NUM> may potentially assist eNB <NUM> to identify the presence of WiFi on the component carriers used for transmission (e.g., for downlink burst transmission). The WLAN measurement report, transmitted by UE <NUM>, may be performed periodically (or at some other interval) or event driven, such as based on the detection of a new WiFi AP or based on a previously detected WiFi AP no longer being detected.

In a third possible implementation for detecting the presence of a nearby WiFi transmission node, UE <NUM> and/or eNB <NUM> may detect the WiFi preamble. The WiFi preamble may be the first part of the Physical Layer Convergence Protocol/Procedure (PLCP) Protocol Data Unit (PDU).

In some implementations, multiple ones of the above-discussed three possible implementations for detecting the presence of a nearby WiFi transmission node may be used. For information detected by UE <NUM>, UE <NUM> may be configured to transmit a WiFi measurement report, to eNB <NUM>, if the measurement, made by UE <NUM>, changes significantly from the previous measurement reported to eNB <NUM>. For example, a measurement report may be transmitted to eNB <NUM> when the number of observed WiFi APs changes.

<FIG> is a flowchart illustrating an example process <NUM> that illustrates a third example embodiment for performing LBT using ED threshold adaptation for LTE-LAA. Process <NUM> may be performed by, for example, eNB <NUM> (i.e., by an eNB that acts as an LTE-LAA node).

In general, with respect to process <NUM>, eNB <NUM> proportionally determines, on a per-UE basis, an ED threshold and the transmit (Tx) power to use for downlink transmissions of the data once the channel has been acquired. This "proportional role," as used by eNB <NUM>, may act to balance two behaviors: (<NUM>) by raising the ED threshold, eNB <NUM> can be more aggressive in accessing the channel; and (<NUM>) by correspondingly lowering the Tx power, eNB <NUM> can create less interference with neighboring transmitters, thus allowing the neighboring transmitters to more frequently access the channel. Stated equivalently, with the proportional rule, by lowering the ED threshold, eNB <NUM> can be less aggressive (more conservative) in accessing the channel but may then correspondingly raise the Tx power to provide better throughput when the channel is being used. With the proportional rule, as described herein, the spatial reuse benefits of raising the ED threshold can be preserved, while ensuring fairness and co-existence due to the lower Tx power.

Process <NUM> may include selecting a modifier, called α herein, that will be used to proportionally modify the ED threshold and the eNB transmit power (block <NUM>). A modifier can be different for different UEs (block <NUM>). In one implementation, the modifier may be selected on a per-UE basis.

As one example, α may be selected as being between zero and <NUM> dBm, where α is set to zero for UEs that are close (e.g., within a certain physical range of eNB <NUM>), <NUM> dBm for UEs that are not close to eNB <NUM> (e.g., near the outer edge of the cell), and linearly scaled between zero and <NUM> dBm for UEs that are between the "close" and "not close" points. In this example, the distance of each particular UE, relative to the cell boundary may be used to modify α. In other implementations, other parameters relating to UE <NUM>, such as the received signal strength, relating to UE <NUM>, may be used to determine α. In some implementations, α may be determined based on information received via a licensed band.

Process <NUM> may further include proportionally modifying the ED threshold and transmit power based on α (block <NUM>). In one implementation, the ED threshold value may be increased based on α (or based on a value obtained from α) and the transmit power, of eNB <NUM> to UE <NUM>, many correspondingly be decreased based on α (or based on a value obtained from α). For example, the following expressions may be used to modify the ED threshold and the transmit power. <MAT> and <MAT>.

In the above expressions, "Ed_Threshold" refers to the ED threshold value, "Initial_ED_Threshold" refers to the default or base ED threshold value, "ED_Thresh_Raise_Value" refers to the amount to increase the default value of the ED threshold, "Tx_Power" refers to the transmit power of eNB <NUM> or UE <NUM>, "Max_Power" refers to the maximum possible transmit power, and "Tx_Power_Reduction_Value" refers to the amount to reduce the maximum possible transmit power. In one implementation, ED_Thresh_Raise_Value and Tx_Power_Reduction_Value may both be set equal to α.

As an example of the expressions for ED_Threshold and Tx_Power, as given in the previous paragraph, consider the situation in which the initial ED threshold is -<NUM> dBm, the maximum transmit power is <NUM> dBm, and α is determined to be <NUM> dBm. In this situation, the ED threshold may be calculated as -<NUM> dBm (-<NUM> + <NUM>) and the transmit power may be calculated as <NUM> dBm (<NUM> - <NUM>). Thus, as the ED threshold is made more aggressive, the transmit power may proportionally be decreased. In other words, the ED threshold and the transmit power are be modified in an inverse manner with respect to one another.

Process <NUM> may further include performing the LBT operation using the modified ED threshold and the transmit power (block <NUM>). For example, the LBT operation may include the operations associated with block <NUM> and <NUM> of process <NUM>, or, alternatively or additionally, the LBT operation may include the operations associated with blocks <NUM>-<NUM> of process <NUM>.

<FIG> is a diagram conceptually illustrating an example implementation consistent with process <NUM>. In <FIG>, assume that eNB <NUM> communicates, using licensed and unlicensed channels, with UEs <NUM> and <NUM>. The communication via the unlicensed channels may be performed via LTE-LAA.

In <FIG>, assume that eNB <NUM> is determined to be relatively close to UE <NUM>. For example, via LTE-based communications in the licensed band, eNB <NUM> may determine that UE <NUM> is near eNB <NUM> and/or receives a good signal strength signal from eNB <NUM>. eNB <NUM> may correspondingly determine that α, for UE <NUM>, should be set to zero. As shown, assuming that the default or previously set ED threshold for UE <NUM> is -<NUM> dBm and the default or maximum transmit power is <NUM> dBm, the proportionally modified ED threshold value and transmit power may remain at -<NUM> dBm and <NUM> dBm, respectively.

Assume that UE <NUM> is determined to be farther away from eNB <NUM>. For example, via LTE-based communications in the licensed band, eNB <NUM> may determine that UE <NUM> is near the edge of the coverage area provided by eNB <NUM> and/or receives a poor signal from eNB <NUM>. eNB <NUM> may correspondingly determine that α, for UE <NUM>, should be set to <NUM> dBm. As shown, assuming that the default or previously set ED threshold for UE <NUM> is -<NUM> dBm and the default or maximum transmit power is <NUM> dBm, the proportionally modified ED threshold value and transmit power may be -<NUM> dBm and <NUM> dBm, respectively.

The above-discussion for the setting of the ED threshold for LBT may typically apply in the downlink direction. In some implementations, however, uplink transmissions may be made using LTE-LAA. For example, it may be desirable for UE <NUM> to perform LBT for uplink Physical Uplink Shared CHannel (PUSCH) transmissions.

In some implementations, the ED threshold that should be used at UE <NUM> to perform LBT may be indicated by eNB <NUM>. The ED threshold value at UE <NUM> can be different than that used at eNB <NUM>. In one embodiment, UE <NUM> may always use a fixed (static) ED threshold, such as -<NUM> dBm. In a second possible embodiment, UE <NUM> may use the same ED threshold that is used by eNB <NUM>. In a third possible embodiment, UE <NUM> may use the ED threshold value used by eNB <NUM>, plus an offset. In the second and third embodiments, the threshold may be signaled, semi-statically, by higher level signaling. Alternatively or additionally, the ED threshold can be signaled dynamically by Dedicated Control Information (DCI) using Layer <NUM> signaling. In some implementations, the ED threshold value can be cell specific (common to all UEs in the cell) or can be UE specific (different UEs within a cell may have different ED thresholds).

As used herein, the term "circuitry" or "processing circuitry" may refer to, be part of, or include an Application Specific Integrated Circuit (ASIC), an electronic circuit, a processor (shared, dedicated, or group), and/or memory (shared, dedicated, or group) that execute one or more software or firmware programs, a combinational logic circuit, and/or other suitable hardware components that provide the described functionality.

Embodiments described herein may be implemented into a system using any suitably configured hardware and/or software. <FIG> illustrates, for one embodiment, example components of an electronic device <NUM>. In embodiments, the electronic device <NUM> may be a user equipment UE, an eNB (such as eNB <NUM>), a transmission point, or some other appropriate electronic device. In some embodiments, the electronic device <NUM> may include application circuitry <NUM>, baseband circuitry <NUM>, Radio Frequency (RF) circuitry <NUM>, front-end module (FEM) circuitry <NUM> and one or more antennas <NUM>, coupled together at least as shown.

Application circuitry <NUM> may include one or more application processors. The processors may be coupled with and/or may include memory/storage, such as storage medium <NUM>, 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. In some implementations, storage medium <NUM> may include a non-transitory computer-readable medium. Application circuitry <NUM> may, in some embodiments, connect to or include one or more sensors, such as environmental sensors, cameras, etc..

Baseband circuitry <NUM> may include circuitry such as, but not limited to, one or more single-core or multi-core processors. The baseband circuitry <NUM> may include one or more baseband processors and/or control logic to process baseband signals received from a receive signal path of the RF circuitry <NUM> and to generate baseband signals for a transmit signal path of the RF circuitry <NUM>. Baseband processing circuitry <NUM> may interface with the application circuitry <NUM> for generation and processing of the baseband signals and for controlling operations of the RF circuitry <NUM>. For example, in some embodiments, the baseband circuitry <NUM> may include a second generation (<NUM>) baseband processor 704a, third generation (<NUM>) baseband processor 704b, fourth generation (<NUM>) baseband processor 704c, and/or other baseband processor(s) 704d for other existing generations, generations in development or to be developed in the future (e.g., fifth generation (<NUM>), <NUM>, etc.). The baseband circuitry <NUM> (e.g., one or more of baseband processors 704a-d) may handle various radio control functions that enable communication with one or more radio networks via the RF circuitry <NUM>. The radio control functions may include, but are not limited to, signal modulation/demodulation, encoding/decoding, radio frequency shifting, etc. In some implementations, baseband circuitry <NUM> may be associated with storage medium <NUM> or with another storage medium.

In embodiments where the electronic device <NUM> is implemented in, incorporates, or is otherwise part of an LTE-LAA transmission point, the baseband circuitry <NUM> may be to: identify one or more parameters related to the LTE-LAA transmission point, wherein the LTE-LAA transmission point is in a network that includes a plurality of LTE-LAA transmission points, respective LTE-LAA transmission points having respective parameters; and identify, based on a listen-before-talk (LBT) procedure related to identification of channel occupancy status of respective LTE-LAA transmission points in the plurality of LTE-LAA transmission points that the LTE-LAA transmission point has an un-occupied channel. RF circuitry <NUM> may be to transmit a signal based on the identification.

In some embodiments, modulation/demodulation circuitry of the baseband circuitry <NUM> may include Fast-Fourier Transform (FFT), precoding, and/or constellation mapping/demapping functionality. In some embodiments, encoding/decoding circuitry of the baseband circuitry <NUM> may include convolution, tail-biting convolution, turbo, Viterbi, and/or Low Density Parity Check (LDPC) encoder/decoder functionality. Embodiments of modulation/demodulation and encoder/decoder functionality are not limited to these examples and may include other suitable functionality in other embodiments. In some embodiments, the baseband circuitry <NUM> may include elements of a protocol stack such as, for example, elements of an evolved universal terrestrial radio access network (EUTRAN) protocol including, for example, physical (PHY), media access control (MAC), radio link control (RLC), packet data convergence protocol (PDCP), and/or radio resource control (RRC) elements. A central processing unit (CPU) 704e of the baseband circuitry <NUM> may be configured to run elements of the protocol stack for signaling of the PHY, MAC, RLC, PDCP and/or RRC layers. In some embodiments, the baseband circuitry may include one or more audio digital signal processor(s) (DSP) 704f. The audio DSP(s) 704f may be include elements for compression/decompression and echo cancellation and may include other suitable processing elements in other embodiments.

Baseband circuitry <NUM> may further include memory/storage <NUM>. The memory/storage <NUM> may be used to load and store data and/or instructions for operations performed by the processors of the baseband circuitry <NUM>. Memory/storage <NUM> may particularly include a non-transitory memory. Memory/storage for one embodiment may include any combination of suitable volatile memory and/or non-volatile memory. The memory/storage <NUM> may include any combination of various levels of memory/storage including, but not limited to, read-only memory (ROM) having embedded software instructions (e.g., firmware), random access memory (e.g., dynamic random access memory (DRAM)), cache, buffers, etc. The memory/storage <NUM> may be shared among the various processors or dedicated to particular processors.

Components of the baseband circuitry may be suitably combined in a single chip, a single chipset, or disposed on a same circuit board in some embodiments. In some embodiments, some or all of the constituent components of the baseband circuitry <NUM> and the application circuitry <NUM> may be implemented together such as, for example, on a system on a chip (SOC).

In some embodiments, the RF circuitry <NUM> may include a receive signal path and a transmit signal path. The receive signal path of the RF circuitry <NUM> may include mixer circuitry 706a, amplifier circuitry 706b and filter circuitry 706c. The transmit signal path of the RF circuitry <NUM> may include filter circuitry 706c and mixer circuitry 706a. RF circuitry <NUM> may also include synthesizer circuitry 706d for synthesizing a frequency for use by the mixer circuitry 706a of the receive signal path and the transmit signal path. In some embodiments, the mixer circuitry 706a of the receive signal path may be configured to down-convert RF signals received from the FEM circuitry <NUM> based on the synthesized frequency provided by synthesizer circuitry 706d. The amplifier circuitry 706b may be configured to amplify the down-converted signals and the filter circuitry 706c may be a low-pass filter (LPF) or band-pass filter (BPF) configured to remove unwanted signals from the down-converted signals to generate output baseband signals.

Output baseband signals may be provided to the baseband circuitry <NUM> for further processing. In some embodiments, the output baseband signals may be zero-frequency baseband signals, although this is not a requirement. In some embodiments, mixer circuitry 706a of the receive signal path may comprise passive mixers, although the scope of the embodiments is not limited in this respect.

In some embodiments, the mixer circuitry 706a of the transmit signal path may be configured to up-convert input baseband signals based on the synthesized frequency provided by the synthesizer circuitry 706d to generate RF output signals for the FEM circuitry <NUM>. The baseband signals may be provided by the baseband circuitry <NUM> and may be filtered by filter circuitry 706c. The filter circuitry 706c 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 706a of the receive signal path and the mixer circuitry 706a of the transmit signal path may include two or more mixers and may be arranged for quadrature downconversion and/or upconversion respectively. In some embodiments, the mixer circuitry 706a of the receive signal path and the mixer circuitry 706a of the transmit signal path may include two or more mixers and may be arranged for image rejection (e.g., Hartley image rejection). In some embodiments, the mixer circuitry 706a of the receive signal path and the mixer circuitry 706a may be arranged for direct downconversion and/or direct upconversion, respectively. In some embodiments, the mixer circuitry 706a of the receive signal path and the mixer circuitry 706a of the transmit signal path may be configured for super-heterodyne operation.

In some embodiments, the synthesizer circuitry 706d may be a fractional-N synthesizer or a fractional N/N+<NUM> synthesizer, although the scope of the embodiments is not limited in this respect as other types of frequency synthesizers may be suitable. For example, synthesizer circuitry 706d may be a delta-sigma synthesizer, a frequency multiplier, or a synthesizer comprising a phase-locked loop with a frequency divider.

The synthesizer circuitry 706d may be configured to synthesize an output frequency for use by the mixer circuitry 706a of the RF circuitry <NUM> based on a frequency input and a divider control input. In some embodiments, the synthesizer circuitry 706d may be a fractional N/N+<NUM> synthesizer.

In some embodiments, frequency input may be provided by a voltage-controlled oscillator (VCO), although that is not a requirement.

Synthesizer circuitry 706d of the RF circuitry <NUM> may include a divider, a delay-locked loop (DLL), a multiplexer and a phase accumulator. In some embodiments, the divider may be a dual modulus divider (DMD) and the phase accumulator may be a digital phase accumulator (DPA). In some embodiments, the DMD may be configured to divide the input signal by either N or N+<NUM> (e.g., based on a carry out) to provide a fractional division ratio. In some example embodiments, the DLL may include a set of cascaded, tunable, delay elements, a phase detector, a charge pump and a D-type flip-flop. In these embodiments, the delay elements may be configured to break a VCO period up into Nd equal packets of phase, where Nd is the number of delay elements in the delay line. In this way, the DLL provides negative feedback to help ensure that the total delay through the delay line is one VCO cycle.

In some embodiments, synthesizer circuitry 706d may be configured to generate a carrier frequency as the output frequency, while in other embodiments, the output frequency may be a multiple of the carrier frequency (e.g., twice the carrier frequency, four times the carrier frequency) and used in conjunction with quadrature generator and divider circuitry to generate multiple signals at the carrier frequency with multiple different phases with respect to each other. In some embodiments, the output frequency may be a LO frequency (fLO). In some embodiments, the RF circuitry <NUM> may include an IQ/polar converter.

In some embodiments, the electronic device <NUM> may include additional elements such as, for example, memory/storage, display, camera, sensors, and/or input/output (I/O) interface. In some embodiments, the electronic device of <FIG> may be configured to perform one or more methods, processes, and/or techniques such as those described herein.

In the preceding specification, various embodiments have been described with reference to the accompanying drawings. It will, however, be evident that various modifications and changes may be made thereto, and additional embodiments may be implemented, without departing from the broader scope as set forth in the claims that follow. The specification and drawings are accordingly to be regarded in an illustrative rather than restrictive sense.

For example, while series of signals have been described with regard to <FIG>, the order of the signals may be modified in other implementations. Further, non-dependent signals may be performed in parallel.

It will be apparent that example aspects, as described above, may be implemented in many different forms of software, firmware, and hardware in the implementations illustrated in the figures. The actual software code or specialized control hardware used to implement these aspects should not be construed as limiting. Thus, the operation and behavior of the aspects were described without reference to the specific software code-it being understood that software and control hardware could be designed to implement the aspects based on the description herein.

Further, certain portions may be implemented as "logic" that performs one or more functions. This logic may include hardware, such as an application-specific integrated circuit ("ASIC") or a field programmable gate array ("FPGA"), or a combination of hardware and software.

Claim 1:
A Base Station, BS (<NUM>), that functions as a Long Term Evolution, LTE, Licensed Assisted Access, LAA, transmission point, the BS (<NUM>) comprising circuitry to:
adaptively determine a first energy detection, ED, threshold value for a first User Equipment, UE, and a second ED threshold value for a second UE to use when performing a Listen-Before-Talk, LBT, operation, the adaptive determination including selectively choosing the first and second ED threshold values from at least two or more possible ED threshold values; and
transmit data, to the first UE (<NUM>; <NUM>; <NUM>), and the second UE (<NUM>; <NUM>; <NUM>), via LTE-LAA downlink transmission, the transmission including performing a LBT operation using the adaptively determined first and second ED threshold values;
wherein the BS (<NUM>) transmits to the first UE (<NUM>; <NUM>; <NUM>) based on a first transmit power value and to the second UE (<NUM>; <NUM>; <NUM>) based on a second transmit power value, and when adaptively determining the first and second ED threshold values, the BS (<NUM>) further includes circuitry to:
determine a first modifier value for the first UE (<NUM>; <NUM>; <NUM>) and a second modifier value for the second UE (<NUM>; <NUM>; <NUM>), wherein the second modifier value is different than the first modifier value; and
proportionally modify an ED threshold value and a transmit power value based on the first modifier value to determine the first ED threshold value and a first transmit power value for the first UE, and based on the second modifier value to determine the second ED threshold value and a second transmit power value for the second UE;
wherein the proportional modification comprises inversely modifying the ED threshold value and the transmit power value such that an increase in the ED threshold value corresponds to a decrease in the transmit power value.