WO2017180194A1 - Licensed assisted access ue radio resource measurement and csi measurement apparatus and method - Google Patents

Abstract

Systems and methods of providing DRS measurements in an unlicensed band are generally described. The UE determines whether the DRS power level of the DRS transmission has varied from a power level of a previously received DRS transmission. If so, the UE either does not report the DRS measurement or adjusts the DRS measurement for RRM measurements. In either case, the CSI measurement is still reported. The DRS measurement is averaged with previous DRS measurements if the DRS measurement falls outside a predetermined range from the average. The UE determines the DRS power level variation by the DRS measurement variation, via an indication from the eNB or by other characteristics of the DRS transmission caused by the use of the unlicensed band.

Description

LICENSED ASSISTED ACCESS UE RADIO RESOURCE MEASUREMENT AND CSI MEASUREMENT APPARATUS AND

METHOD

PRIORITY CLAIM

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

Provisional Patent Application Serial No. 62/320,998, filed April 11, 2016, and entitled "LICENSED ASSISTED ACCESS UE RADIO RESOURCE MEASUREMENT AND CSI MEASUREMENT APPARATUS AND METHOD," which is incorporated herein by reference in its entirety.

TECHNICAL FIELD

[0002] Embodiments pertain to radio access networks. Some embodiments relate to reference signal measurement in various cellular and wireless local area network (WLAN) networks, including Third Generation Partnership Project Long Term Evolution (3 GPP LTE) networks and LTE advanced (LTE-A) networks as well as 4^th generation (4G) networks and 5^th generation (5G) networks. Some embodiments relate to various types of measurements in License Assisted Access (LAA) networks.

BACKGROUND

[0003] The use of 3 GPP LTE systems (including both LTE and LTE-A systems) has increased due to both an increase in the types of devices user equipment (UEs) using network resources as well as the amount of data and bandwidth being used by various applications, such as video streaming, operating on these UEs. LTE networks typically operate in a number of radio frequency (RF) bands licensed to a wireless operator in which base stations (evolved node Bs (eNBs)) and an increasing number and varying type of user equipment (UE) communicate. Communications are typically limited to the licensed bands, which are regulated by the federal government; the growth of network use by user devices and machine type communication (MTC) devices has however strained use beyond the limits of the licensed bands. [0004] To alleviate the stress on the licensed bands, operators have turned to the use of unlicensed spectrum such as the Industrial, Scientific and Medical RF spectrum (ISM band) in Licensed Assisted Access (LAA) communications. While only LTE systems are able to legally operate in LTE bands, other systems, such as Wireless Local Area Network (WLAN) systems, coexist with LAA systems in the unlicensed spectrum. The use of the unlicensed spectrum comes at the cost of increased complexity, as well as a variety of issues related to access to the unlicensed spectrum as this spectrum is shared by a variety of radio access technologies. For example, certain assumptions in terms of reference signal measurement may no longer hold true when the LAA spectrum is used to transmit the reference signals. This may cause issues with the characteristics determined based on the reference signal measurements made at the UE.

BRIEF DESCRIPTION OF THE FIGURES

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

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

[0007] FIG. 2 illustrates components of a communication device in accordance with some embodiments.

[0008] FIG. 3 illustrates a block diagram of a communication device in accordance with some embodiments.

[0009] FIG. 4 illustrates another block diagram of a communication device in accordance with some embodiments.

[0010] FIG. 5 illustrates reference signal fluctuations in the LAA spectrum in accordance with some embodiments.

[0011] FIG. 6 illustrates a flow diagram of reference signal reporting in accordance with some embodiments. DETAILED DESCRIPTION

[0012] The following description and the drawings sufficiently illustrate specific embodiments to enable those skilled in the art to practice them. Other embodiments may incorporate structural, logical, electrical, process, and other changes. Portions and features of some embodiments may be included in, or substituted for, those of other embodiments. Embodiments set forth in the claims encompass all available equivalents of those claims.

[0013] FIG. 1 shows an example of a portion of an end-to-end network architecture of a LTE network in accordance with some embodiments. As used herein, an LTE network refers to both LTE and LTE Advanced (LTE-A) networks as well as other versions of LTE networks to be developed. The network 100 may comprise a radio access network (RAN) (e.g., as depicted, the E-UTRAN or evolved universal terrestrial radio access network) 101 and core network 120 (e.g., shown as an evolved packet core (EPC)) coupled together through an S I interface 115. For convenience and brevity, only a portion of the core network 120, as well as the RAN 101, is shown in the example.

[0014] The core network 120 may include a mobility management entity

(MME) 122, serving gateway (serving GW) 124, and packet data network gateway (PDN GW) 126. The RAN 101 may include evolved node Bs (eNBs) 104 (which may operate as base stations) for communicating with user equipment (UE) 102. The eNBs 104 may include macro eNBs 104a and low power (LP) eNBs 104b. Other elements, such as a Home Location Register (HLR)/Home Subscriber Server (HSS), a database including subscriber information of a 3GPP network that may perform configuration storage, identity management and user state storage, and a Policy and Charging Rule Function (PCRF) that performs policy decision for dynamically applying Quality of Service (QoS) and charging policy per service flow, are not shown for convenience.

[0015] The MME 122 may be similar in function to the control plane of legacy Serving GPRS Support Nodes (SGSN). The MME 122 may manage mobility aspects in access such as gateway selection and tracking area list management, performing both mobility management (MM) and session management (SM). The Non-Access Stratum (NAS) is a part of the control plane between a UE 102 and the MME 122. The NAS is used for signaling between the UE 102 and the EPC in the LTE UMTS protocol stack. The NAS supports UE mobility and session management for establishing and maintaining an IP connection between the UE 102 and PDN GW 126.

[0016] The serving GW 124 may terminate the user plane interface toward the RAN 101, and route data packets between the RAN 101 and the core network 120. In addition, the serving GW 124 may be a local mobility anchor point for inter-eNB handovers and also may provide an anchor for inter-3GPP mobility. Other responsibilities may include lawful intercept, charging, and policy enforcement, packet routing, idle mode packet buffering, and triggering an MME to page a UE. The serving GW 124 and the MME 122 may be implemented in one physical node or separate physical nodes.

[0017] The PDN GW 126 may terminate a SGi interface toward the packet data network (PDN). The PDN GW 126 may route data packets between the EPC 120 and the external PDN, and may perform policy enforcement and charging data collection UE IP address assignment, packet screening and filtering. The PDN GW 126 may also provide an anchor point for mobility devices with a non-LTE access. The external PDN can be any kind of IP network, as well as an IP Multimedia Subsystem (IMS) domain. The PDN GW 126 and the serving GW 124 may be implemented in a single physical node or separate physical nodes.

[0018] The eNBs 104 (macro and micro) may terminate the air interface protocol and may be the first point of contact for a UE 102. In some embodiments, an eNB 104 may fulfill various logical functions for the RAN 101 including, but not limited to, RNC (radio network controller functions) such as radio bearer management, uplink and downlink dynamic radio resource management and data packet scheduling, and mobility management. In accordance with embodiments, UEs 102 may be configured to communicate orthogonal frequency division multiplexed (OFDM) communication signals with an eNB 104 over a multicarrier communication channel in accordance with an OFDMA communication technique. The OFDM signals may comprise a plurality of orthogonal subcarriers. [0019] The S 1 interface 115 may be the interface that separates the RAN

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

[0020] With cellular networks, LP cells 104b may be typically used to extend coverage to indoor areas where outdoor signals do not reach well, or to add network capacity in areas with dense usage. In particular, it may be desirable to enhance the coverage of a wireless communication system using cells of different sizes, macrocells, microcells, picocells, and femtocells, to boost system performance. The cells of different sizes may operate on the same frequency band, or may operate on different frequency bands with each cell operating in a different frequency band or only cells of different sizes operating on different frequency bands. As used herein, the term LP eNB refers to any suitable relatively LP eNB for implementing a smaller cell (smaller than a macro cell) such as a femtocell, a picocell, or a microcell. Femtocell eNBs may be typically provided by a mobile network operator to its residential or enterprise customers. A femtocell may be typically the size of a residential gateway or smaller and generally connect to a broadband line. The femtocell may connect to the mobile operator's mobile network and provide extra coverage in a range of typically 30 to 50 meters. Thus, a LP eNB 104b might be a femtocell eNB. In some embodiments, when the LP eNB 104b is a Home eNB (HeNB), a HeNB Gateway may be provided between the HeNB and the MME/Service Gateway. This HeNB Gateway may control multiple HeNBs and provide user data and signal traffic from the HeNBs towards the MME/Service Gateway. Similarly, a picocell may be a wireless communication system typically covering a small area, such as in-building (offices, shopping malls, train stations, etc.), or more recently in-aircraft. A picocell eNB may generally connect through the X2 link to another eNB such as a macro eNB through its base station controller (BSC) functionality and/or connect via an SI interface to an MME/Service Gateway. Thus, LP eNB may be implemented with a picocell eNB since it may be coupled to a macro eNB 104a via an X2 interface. Picocell eNBs or other LP eNBs LP eNB 104b may incorporate some or all functionality of a macro eNB LP eNB 104a. In some cases, this may be referred to as an access point base station or enterprise femtocell.

[0021] The eNBs 104 may provide periodic reference signaling messages for various purposes. The reference signaling messages may include a cell- specific reference signal (CRS), which may be used for cell search and initial acquisition of communication with the eNB, downlink channel quality measurements and downlink channel estimation for coherent demodulation or detection. A Channel Quality Indication (CQI) may be used to indicate a measurement of the channel quality including carrier level received signal strength indication (RSSI) and bit error rate (BER). A channel state information reference signal (CSI-RS) may be used to estimate the channel and report channel quality information. A Discovery Reference Signal (DRS) may include one or more of the above signals (synchronization and reference signals) and may be specific to an individual UE. The use of DRS was introduced in LTE Release 12 to facilitate fast transition of small cells (e.g., femto or pico cells) from the OFF to the ON state by transmitting low duty cycle signals for radio resource management (RRM) measurement during the OFF state. Transmission of the DRS allow UEs to discover and measure a dormant cell, among other uses.

[0022] FIG. 2 illustrates components of a communication device in accordance with some embodiments. The communication device 200 may be a UE, eNB or other network component as described herein. The communication device 200 may be a stationary, non-mobile device or may be a mobile device. In some embodiments, the UE 200 may include application circuitry 202, baseband circuitry 204, Radio Frequency (RF) circuitry 206, front-end module (FEM) circuitry 208 and one or more antennas 210, coupled together at least as shown. At least some of the baseband circuitry 204, RF circuitry 206, and FEM circuitry 208 may form a transceiver. In some embodiments, other network elements, such as the MME may contain some or all of the components shown in FIG. 2. [0023] The application or processing circuitry 202 may include one or more application processors. For example, the application circuitry 202 may include circuitry such as, but not limited to, one or more single-core or multi- core processors. The processor(s) may include any combination of general- purpose processors and dedicated processors (e.g., graphics processors, application processors, etc.). The processors may be coupled with and/or may include memory/storage and may be configured to execute instructions stored in the memory/storage to enable various applications and/or operating systems to run on the system.

[0024] The baseband circuitry 204 may include circuitry such as, but not limited to, one or more single-core or multi-core processors. The baseband circuitry 204 may include one or more baseband processors and/or control logic to process baseband signals received from a receive signal path of the RF circuitry 206 and to generate baseband signals for a transmit signal path of the RF circuitry 206. Baseband processing circuity 204 may interface with the application circuitry 202 for generation and processing of the baseband signals and for controlling operations of the RF circuitry 206. For example, in some embodiments, the baseband circuitry 204 may include a second generation (2G) baseband processor 204a, third generation (3G) baseband processor 204b, fourth generation (4G) baseband processor 204c, and/or other baseband processor(s) 204d for other existing generations, generations in development or to be developed in the future (e.g., fifth generation (5G), 5G, etc.). The baseband circuitry 204 (e.g., one or more of baseband processors 204a-d) may handle various radio control functions that enable communication with one or more radio networks via the RF circuitry 206. The radio control functions may include, but are not limited to, signal modulation/demodulation,

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

[0025] In some embodiments, the baseband circuitry 204 may include elements of a protocol stack such as, for example, elements of an Evolved UTRON (EUTRAN) protocol including, for example, physical (PHY), media access control (MAC), radio link control (RLC), packet data convergence protocol (PDCP), radio resource control (RRC) elements, and/or Non-Access Stratum (NAS) elements. A central processing unit (CPU) 204e of the baseband circuitry 204 may be configured to run elements of the protocol stack for signaling of the PHY, MAC, RLC, PDCP and/or RRC layers, and/or NAS. In some embodiments, the baseband circuitry may include one or more audio digital signal processor(s) (DSP) 204f. The audio DSP(s) 204f may be include elements for compression/decompression and echo cancellation and may include other suitable processing elements in other embodiments. Components of the baseband circuitry may be suitably combined in a single chip, a single chipset, or disposed on a same circuit board in some embodiments. In some embodiments, some or all of the constituent components of the baseband circuitry 204 and the application circuitry 202 may be implemented together such as, for example, on a system on a chip (SOC).

[0026] In some embodiments, the baseband circuitry 204 may provide for communication compatible with one or more radio technologies. For example, in some embodiments, the baseband circuitry 204 may support communication with an EUTRAN and/or other wireless metropolitan area networks (WMAN), a wireless local area network (WLAN), a wireless personal area network (WPAN). Embodiments in which the baseband circuitry 204 is configured to support radio communications of more than one wireless protocol may be referred to as multi-mode baseband circuitry. In some embodiments, the device can be configured to operate in accordance with communication standards or other protocols or standards, including Institute of Electrical and Electronic Engineers (IEEE) 802.16 wireless technology (WiMax), IEEE 802.11 wireless technology (WiFi) including IEEE 802.11 ad, which operates in the 60 GHz millimeter wave spectrum, various other wireless technologies such as global system for mobile communications (GSM), enhanced data rates for GSM evolution (EDGE), GSM EDGE radio access network (GERAN), universal mobile telecommunications system (UMTS), UMTS terrestrial radio access network (UTRAN), or other 2G, 3G, 4G, 5G, etc. technologies either already developed or to be developed.

[0027] RF circuitry 206 may enable communication with wireless networks using modulated electromagnetic radiation through a non-solid medium. In various embodiments, the RF circuitry 206 may include switches, filters, amplifiers, etc. to facilitate the communication with the wireless network. RF circuitry 206 may include a receive signal path which may include circuitry to down-convert RF signals received from the FEM circuitry 208 and provide baseband signals to the baseband circuitry 204. RF circuitry 206 may also include a transmit signal path which may include circuitry to up-convert baseband signals provided by the baseband circuitry 204 and provide RF output signals to the FEM circuitry 208 for transmission.

[0028] In some embodiments, the RF circuitry 206 may include a receive signal path and a transmit signal path. The receive signal path of the RF circuitry 206 may include mixer circuitry 206a, amplifier circuitry 206b and filter circuitry 206c. The transmit signal path of the RF circuitry 206 may include filter circuitry 206c and mixer circuitry 206a. RF circuitry 206 may also include synthesizer circuitry 206d for synthesizing a frequency for use by the mixer circuitry 206a of the receive signal path and the transmit signal path. In some embodiments, the mixer circuitry 206a of the receive signal path may be configured to down-convert RF signals received from the FEM circuitry 208 based on the synthesized frequency provided by synthesizer circuitry 206d. The amplifier circuitry 206b may be configured to amplify the down-converted signals and the filter circuitry 206c may be a low -pass filter (LPF) or band-pass filter (BPF) configured to remove unwanted signals from the down-converted signals to generate output baseband signals. Output baseband signals may be provided to the baseband circuitry 204 for further processing. In some embodiments, the output baseband signals may be zero-frequency baseband signals, although this is not a requirement. In some embodiments, mixer circuitry 206a of the receive signal path may comprise passive mixers, although the scope of the embodiments is not limited in this respect. [0029] In some embodiments, the mixer circuitry 206a of the transmit signal path may be configured to up-convert input baseband signals based on the synthesized frequency provided by the synthesizer circuitry 206d to generate RF output signals for the FEM circuitry 208. The baseband signals may be provided by the baseband circuitry 204 and may be filtered by filter circuitry 206c. The filter circuitry 206c may include a low-pass filter (LPF), although the scope of the embodiments is not limited in this respect.

[0030] In some embodiments, the mixer circuitry 206a of the receive signal path and the mixer circuitry 206a of the transmit signal path may include two or more mixers and may be arranged for quadrature downconversion and/or upconversion respectively. In some embodiments, the mixer circuitry 206a of the receive signal path and the mixer circuitry 206a of the transmit signal path may include two or more mixers and may be arranged for image rejection (e.g., Hartley image rejection). In some embodiments, the mixer circuitry 206a of the receive signal path and the mixer circuitry 206a may be arranged for direct downconversion and/or direct upconversion, respectively. In some embodiments, the mixer circuitry 206a of the receive signal path and the mixer circuitry 206a of the transmit signal path may be configured for super-heterodyne operation.

[0031] In some embodiments, the output baseband signals and the input baseband signals may be analog baseband signals, although the scope of the embodiments is not limited in this respect. In some alternate embodiments, the output baseband signals and the input baseband signals may be digital baseband signals. In these alternate embodiments, the RF circuitry 206 may include analog-to-digital converter (ADC) and digital-to-analog converter (DAC) circuitry and the baseband circuitry 204 may include a digital baseband interface to communicate with the RF circuitry 206.

[0032] In some dual-mode embodiments, a separate radio IC circuitry may be provided for processing signals for each spectrum, although the scope of the embodiments is not limited in this respect.

[0033] In some embodiments, the synthesizer circuitry 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 circuitry 206d may be a delta-sigma synthesizer, a frequency multiplier, or a synthesizer comprising a phase-locked loop with a frequency divider.

[0034] The synthesizer circuitry 206d may be configured to synthesize an output frequency for use by the mixer circuitry 206a of the RF circuitry 206 based on a frequency input and a divider control input. In some embodiments, the synthesizer circuitry 206d may be a fractional N N+l synthesizer.

[0035] In some embodiments, frequency input may be provided by a voltage controlled oscillator (VCO), although that is not a requirement. Divider control input may be provided by either the baseband circuitry 204 or the applications processor 202 depending on the desired output frequency. In some embodiments, a divider control input (e.g., N) may be determined from a lookup table based on a channel indicated by the applications processor 202.

[0036] Synthesizer circuitry 206d of the RF circuitry 206 may include a divider, a delay -locked loop (DLL), a multiplexer and a phase accumulator. In some embodiments, the divider may be a dual modulus divider (DMD) and the phase accumulator may be a digital phase accumulator (DPA). In some embodiments, the DMD may be configured to divide the input signal by either N or N+l (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.

[0037] In some embodiments, synthesizer circuitry 206d may be configured to generate a carrier frequency as the output frequency, while in other embodiments, the output frequency may be a multiple of the carrier frequency (e.g., twice the carrier frequency, four times the carrier frequency) and used in conjunction with quadrature generator and divider circuitry to generate multiple signals at the carrier frequency with multiple different phases with respect to each other. In some embodiments, the output frequency may be a LO frequency (fLo). In some embodiments, the RF circuitry 206 may include an IQ/polar converter. [0038] FEM circuitry 208 may include a receive signal path which may include circuitry configured to operate on RF signals received from one or more antennas 210, amplify the received signals and provide the amplified versions of the received signals to the RF circuitry 206 for further processing. FEM circuitry 208 may also include a transmit signal path which may include circuitry configured to amplify signals for transmission provided by the RF circuitry 206 for transmission by one or more of the one or more antennas 210.

[0039] In some embodiments, the FEM circuitry 208 may include a

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

[0040] In some embodiments, the communication device 200 may include additional elements such as, for example, memory/storage, display, camera, sensor, and/or input/output (I/O) interface as described in more detail below. In some embodiments, the communication device 200 described herein may be part of a portable wireless communication device, such as a personal digital assistant (PDA), a laptop or portable computer with wireless

communication capability, a web tablet, a wireless telephone, a smartphone, a wireless headset, a pager, an instant messaging device, a digital camera, an access point, a television, a medical device (e.g., a heart rate monitor, a blood pressure monitor, etc.), or other device that may receive and/or transmit information wirelessly. In some embodiments, the communication device 200 may include one or more user interfaces designed to enable user interaction with the system and/or peripheral component interfaces designed to enable peripheral component interaction with the system. For example, the communication device 200 may include one or more of a keyboard, a keypad, a touchpad, a display, a sensor, a non-volatile memory port, a universal serial bus (USB) port, an audio jack, a power supply interface, one or more antennas, a graphics processor, an application processor, a speaker, a microphone, and other I/O components. The display may be an LCD or LED screen including a touch screen. The sensor may include a gyro sensor, an accelerometer, a proximity sensor, an ambient light sensor, and a positioning unit. The positioning unit may communicate with components of a positioning network, e.g., a global positioning system (GPS) satellite.

[0041] The antennas 210 may comprise 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 multiple-output (MIMO) embodiments, the antennas 210 may be effectively separated to take advantage of spatial diversity and the different channel characteristics that may result.

[0042] Although the communication device 200 is illustrated as having several separate functional elements, one or more of the functional elements may be combined and may be implemented by combinations of software-configured elements, such as processing elements including digital signal processors (DSPs), and/or other hardware elements. For example, some elements may comprise one or more microprocessors, DSPs, field-programmable gate arrays (FPGAs), application specific integrated circuits (ASICs), radio-frequency integrated circuits (RFICs) and combinations of various hardware and logic circuitry for performing at least the functions described herein. In some embodiments, the functional elements may refer to one or more processes operating on one or more processing elements.

[0043] Embodiments may be implemented in one or a combination of hardware, firmware and software. Embodiments may also be implemented as instructions stored on a computer-readable storage device, which may be read and executed by at least one processor to perform the operations described herein. A computer-readable storage device may include any non-transitory mechanism for storing information in a form readable by a machine (e.g., a computer). For example, a computer-readable storage device may include readonly memory (ROM), random-access memory (RAM), magnetic disk storage media, optical storage media, flash-memory devices, and other storage devices and media. Some embodiments may include one or more processors and may be configured with instructions stored on a computer-readable storage device.

[0044] FIG. 3 is a block diagram of a communication device in accordance with some embodiments. The device may be a UE, for example, such as the UE shown in FIG. 1. The physical layer circuitry 302 may perform various encoding and decoding functions that may include formation of baseband signals for transmission and decoding of received signals. The communication device 300 may also include medium access control layer (MAC) circuitry 304 for controlling access to the wireless medium. The communication device 300 may also include processing circuitry 306, such as one or more single-core or multi-core processors, and memory 308 arranged to perform the operations described herein. The physical layer circuitry 302, MAC circuitry 304 and processing circuitry 306 may handle various radio control functions that enable communication with one or more radio networks compatible with one or more radio technologies. The radio control functions may include signal modulation, encoding, decoding, radio frequency shifting, etc. For example, similar to the device shown in FIG. 2, in some embodiments, communication may be enabled with one or more of a WMAN, a WLAN, and a WPAN. In some embodiments, the communication device 300 can be configured to operate in accordance with 3GPP standards or other protocols or standards, including WiMax, WiFi, WiGig, GSM, EDGE, GERAN, UMTS, UTPvAN, or other 3G, 3G, 4G, 5G, etc. technologies either already developed or to be developed. The communication device 300 may include transceiver circuitry 312 to enable communication with other external devices wirelessly and interfaces 314 to enable wired communication with other external devices. As another example, the transceiver circuitry 312 may perform various transmission and reception functions such as conversion of signals between a baseband range and a Radio Frequency (RF) range.

[0045] The antennas 301 may comprise 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 MIMO embodiments, the antennas 301 may be effectively separated to take advantage of spatial diversity and the different channel characteristics that may result.

[0046] Although the communication device 300 is illustrated as having several separate functional elements, one or more of the functional elements may be combined and may be implemented by combinations of software-configured elements, such as processing elements including DSPs, and/or other hardware elements. For example, some elements may comprise one or more

microprocessors, DSPs, FPGAs, ASICs, RFICs and combinations of various hardware and logic circuitry for performing at least the functions described herein. In some embodiments, the functional elements may refer to one or more processes operating on one or more processing elements. 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.

[0047] FIG. 4 illustrates another block diagram of a communication device in accordance with some embodiments. In alternative embodiments, the communication device 400 may operate as a standalone device or may be connected (e.g., networked) to other communication devices. In a networked deployment, the communication device 400 may operate in the capacity of a server communication device, a client communication device, or both in server- client network environments. In an example, the communication device 400 may act as a peer communication device in peer-to-peer (P2P) (or other distributed) network environment. The communication device 400 may be a UE, eNB, PC, a tablet PC, a STB, a PDA, a mobile telephone, a smart phone, a web appliance, a network router, switch or bridge, or any communication device capable of executing instructions (sequential or otherwise) that specify actions to be taken by that communication device. Further, while only a single communication device is illustrated, the term "communication device" shall also be taken to include any collection of communication devices that individually or jointly execute a set (or multiple sets) of instructions to perform any one or more of the methodologies discussed herein, such as cloud computing, software as a service (SaaS), other computer cluster configurations. [0048] Examples, as described herein, may include, or may operate on, logic or a number of components, modules, or mechanisms. Modules are tangible entities (e.g., hardware) capable of performing specified operations and may be configured or arranged in a certain manner. In an example, circuits may be arranged (e.g., internally or with respect to external entities such as other circuits) in a specified manner as a module. In an example, the whole or part of one or more computer systems (e.g., a standalone, client or server computer system) or one or more hardware processors may be configured by firmware or software (e.g., instructions, an application portion, or an application) as a module that operates to perform specified operations. In an example, the software may reside on a communication device readable medium. In an example, the software, when executed by the underlying hardware of the module, causes the hardware to perform the specified operations.

[0049] Accordingly, the term "module" is understood to encompass a tangible entity, be that an entity that is physically constructed, specifically configured (e.g., hardwired), or temporarily (e.g., transitorily) configured (e.g., programmed) to operate in a specified manner or to perform part or all of any operation described herein. Considering examples in which modules are temporarily configured, each of the modules need not be instantiated at any one moment in time. For example, where the modules comprise a general -purpose hardware processor configured using software, the general-purpose hardware processor may be configured as respective different modules at different times. Software may accordingly configure a hardware processor, for example, to constitute a particular module at one instance of time and to constitute a different module at a different instance of time.

[0050] Communication device (e.g., computer system) 400 may include a hardware processor 402 (e.g., a central processing unit (CPU), a graphics processing unit (GPU), a hardware processor core, or any combination thereof), a main memory 404 and a static memory 406, some or all of which may communicate with each other via an interlink (e.g., bus) 408. The

communication device 400 may further include a display unit 410, an alphanumeric input device 412 (e.g., a keyboard), and a user interface (UI) navigation device 414 (e.g., a mouse). In an example, the display unit 410, input device 412 and UI navigation device 414 may be a touch screen display. The communication device 400 may additionally include a storage device (e.g., drive unit) 416, a signal generation device 418 (e.g., a speaker), a network interface device 420, and one or more sensors 421, such as a global positioning system (GPS) sensor, compass, accelerometer, or other sensor. The communication device 400 may include an output controller 428, such as a serial (e.g., universal serial bus (USB), parallel, or other wired or wireless (e.g., infrared (IR), near field communication (NFC), etc.) connection to communicate or control one or more peripheral devices (e.g., a printer, card reader, etc.).

[0051] The storage device 416 may include a communication device readable medium 422 on which is stored one or more sets of data structures or instructions 424 (e.g., software) embodying or utilized by any one or more of the techniques or functions described herein. The instructions 424 may also reside, completely or at least partially, within the main memory 404, within static memory 406, or within the hardware processor 402 during execution thereof by the communication device 400. In an example, one or any combination of the hardware processor 402, the main memory 404, the static memory 406, or the storage device 416 may constitute communication device readable media.

[0052] While the communication device readable medium 422 is illustrated as a single medium, the term "communication device readable medium" may include a single medium or multiple media (e.g., a centralized or distributed database, and/or associated caches and servers) configured to store the one or more instructions 424.

[0053] The term "communication device readable medium" may include any medium that is capable of storing, encoding, or carrying instructions for execution by the communication device 400 and that cause the communication device 400 to perform any one or more of the techniques of the present disclosure, or that is capable of storing, encoding or carrying data structures used by or associated with such instructions. Non-limiting communication device readable medium examples may include solid-state memories, and optical and magnetic media. Specific examples of communication device readable media may include: non-volatile memory, such as semiconductor memory devices (e.g., Electrically Programmable Read-Only Memory (EPROM), Electrically Erasable Programmable Read-Only Memory (EEPROM)) and flash memory devices; magnetic disks, such as internal hard disks and removable disks;

magneto-optical disks; Random Access Memory (RAM); and CD-ROM and DVD-ROM disks. In some examples, communication device readable media may include non-transitory communication device readable media. In some examples, communication device readable media may include communication device readable media that is not a transitory propagating signal.

[0054] The instructions 424 may further be transmitted or received over a communications network 426 using a transmission medium via the network interface device 420 utilizing any one of a number of transfer protocols (e.g., frame relay, internet protocol (IP), transmission control protocol (TCP), user datagram protocol (UDP), hypertext transfer protocol (HTTP), etc.). Example communication networks may include a local area network (LAN), a wide area network (WAN), a packet data network (e.g., the Internet), mobile telephone networks (e.g., cellular networks), Plain Old Telephone (POTS) networks, and wireless data networks (e.g., IEEE 802.11 family of standards known as WiFi®, IEEE 802.16 family of standards known as WiMax®), IEEE 802.15.4 family of standards, a LTE family of standards, a UMTS family of standards, peer-to-peer (P2P) networks, among others. In an example, the network interface device 420 may include one or more physical jacks (e.g., Ethernet, coaxial, or phone jacks) or one or more antennas to connect to the communications network 426. In an example, the network interface device 420 may include a plurality of antennas to wirelessly communicate using at least one of single-input multiple -output (SIMO), MIMO, or multiple-input single-output (MISO) techniques. In some examples, the network interface device 420 may wirelessly communicate using Multiple User MIMO techniques. The term "transmission medium" shall be taken to include any intangible medium that is capable of storing, encoding or carrying instructions for execution by the communication device 400, and includes digital or analog communications signals or other intangible medium to facilitate communication of such software.

[0055] As above, Release 12 of the 3GPP specification introduced DRS

(TS 36.211 vl2.4.0, Section 6.11). The DRS may support synchronization and RRM measurement for both large and small cells, as well as measurement of channel conditions. The DRS may be periodically transmitted from an eNB over an unlicensed spectrum band. The DRS may include a CRS and/or a CSI-RS (as well as a Primary Synchronization Signal and/or Secondary Synchronization Signal). In one definition, a small cell may transmit signals of low power, e.g., up to about 30dBm, and encompassing a small area, e.g., 100m or less, such that only a few users (e.g., tens of users) may be served. Small cells may operate in both an "on" (or active) state or an "off (or dormant) state. This may permit a small cell to become dormant when unused, thereby decreasing interference generated by the small cell in neighboring active small cells.

[0056] The use of the LTE band for both data and control signals may be unduly limiting with the increase in the number and type of devices. In particular, the eNB and UE may undertake RRM and CSI measurements in the LAA spectrum instead of, or in addition to, use in the LTE spectrum. The UE may measure the DRS to generate a DRS measurement report (also referred to herein as a DRS report, a RRM report when RRM measurements are transmitted and a CSI report when CSI measurements are transmitted) and transmit the DRS report to the eNB. However, the use of DRS for channel estimation and handover in the LAA spectrum may encounter issues that are not present in the LTE spectrum. In particular, the inherent nature of the contention-based access system may not allow DRS signals to be transmitted and measured at regular intervals, instead being used at "bursty" intervals. The eNB may, however, expect the DRS measurement to be periodically performed by the UE based on a consistent reference power across measurements. This may result in an inconsistent measurement accuracy due to lack of received signal samples if the period of the DRS transmission is too sparse.

[0057] In addition, unlike LTE transmissions from the eNB whose transmissions are constrained to predetermined bandwidths, the bandwidth of the LAA transmissions from eNB may vary dramatically due to dramatic variation of usage by other, non-LTE devices. Correspondingly, the bandwidth of the LAA DRS transmissions may vary correspondingly. Although the available LAA bandwidth may vary, transmission power by the eNB, however, may only be able to vary within a certain range due to FCC or other governmental transmission requirements. For example, the transmission power of the DRS, rather than remaining constant in the LAA bands, may change with changing amount of LAA spectrum being available for transmission by the eNB.

[0058] Thus, the power level of DRS transmissions in the LAA spectrum may vary significantly from the eNB. This may add an additional element of complexity to UE measurements as the RSRP or RSRQ, for example, may vary not only due to channel conditions, but also due to the transmission power variation. This is problematic as in 3GPP, the UE may assume that the transmission power for CRS and/or CSI-RS in the DRS is constant, regardless of the subframe in which the DRS is transmitted within the Discovery

Measurement Timing Configuration (DMTC). This is to say that, while the measurement at the UE is assumed to be consistent to sustain a radio link to a serving cell, the power level may vary. For RRM measurements, however, the network may unnecessarily effect UE handover to another cell if the power level varies significantly. Although emphasized herein, handover is only one of the functions used for RRM measurements. This may cause a large amount of unnecessary control overhead in the EPC (as well as with the UE) and lead to a substantially reduced connection strength. CSI measurement variation may also be problematic, but may be less so comparatively as switching the channel may use less control overhead due to communication with the same eNB being maintained, as well as leading to channel use that is only slightly inferior to the optimal channel. In either case, however, it would be desirable when the eNB provides DRS using the LAA spectrum for the UE to determine and adjust for DRS when the source of DRS measurement fluctuation for RRM measurements is power-based rather than channel-based. This is in addition to CSI measurements varying due to transmission power rather than channel-based effects. The eNB indicates a subframe for CSI measurement. In CRS-TMs, the LAA UE may measure the CSI using the CRS in a subframe indicated by the eNB. In DMRS-TMs, the LAA UE may measure the CSI using the CSI-RS in a subframe indicated by the eNB.

[0059] FIG. 5 illustrates reference signal fluctuations in the LAA spectrum in accordance with some embodiments. The reference signal may be a DRS (CRS and CSI-RS), for example, transmitted by an eNB and measured at a UE. The eNB and UE may be any of the devices described herein. The UE may, for example, be a user-based device such as a smartphone, tablet computer or wearable device, or may be a MTC device or other non-user based device, such as a sensor.

[0060] As above, the DRS (irs) may be transmitted in different transmission opportunities (TXOP) or in any subframe within different DMTCs. Due to the listen before talk (LBT) nature of transmission on the LAA spectrum, the DRS transmitted over an extended period based on the overall LAA spectrum use by other devices. Thus, rather than being transmitted periodically in a particular subframe, the DRS may be transmitted in the LAA spectrum semi-periodically or randomly, for example, being transmitted at different subframes within different frames. As shown, some frames may not have any subframes that contain DRS. The DRS, and LAA transmissions in general, may be bursty in nature. As used herein a DRS is used synonymously with a DRS transmission.

[0061] Each DRS transmission may vary significantly in power from one transmission to the next. As shown, this variation may be 50-100% from the minimum transmission level, although this range is not exclusive. A significant variation may be one that results in an undesirable change in channel or handover to a different eNB, that is a change that would otherwise not occur if the power variation was not present. The DRS may be received and the fluctuation may be measured by the UE.

[0062] As the DRS are transmitted using the LAA spectrum, the UE may determine that the DRS transmission power used for RRM measurements in the DMTC may not be constant under certain LAA channel or network deployment conditions, unlike LTE DRS transmissions that may be transmitted in the

PDSCH. In some embodiments, as the UE may not know the bandwidth used by the eNB to transmit the DRS signal, the UE may compare the DRS

measurements to other recent DRS measurements on the same channel.

[0063] For example, the UE may apply averaging across DRS transmissions to determine whether a particular DRS measurement should be reported to the eNB and/or corrected. In some embodiments, the UE may not apply averaging across burst transmissions in cases in which the UE determines that the transmission power for the DRS is consistent and otherwise apply averaging. For example, the UE may take the DRS measurement of the previous 3-5 DRS transmissions (stored in the UE memory, the number of DRS transmissions able to be larger if desired) and determine the average and standard deviation of the DRS measurement. If the current DRS measurement lies outside of a predetermined range, e.g., 1, 1.5 or 2 standard deviations from the average DRS measurement, the UE may take corrective measures. The corrective measures may include, for example, the UE adjusting the

measurement before reporting the adjusted measurement to the eNB, not reporting the measurement, or reporting the measurement as measured but with an indication that the measurement may be an abnormality.

[0064] The UE may adjust the measurement, for example, using the most recent DRS measurement value and/or the average DRS value. For example, the UE may report the average of the current DRS value and one or both of the most recent DRS measurement value and/or the average DRS value. If the UE reports the original DRS measurement, an unused bit in the uplink transmission may be used to indicate the adjustment to the eNB. The UE may also merely drop the current outlier measurement.

[0065] The eNB may store the variation in DRS measurement. Thus, whatever DRS value the UE reports to the eNB, the eNB may also be able to determine whether the reported DRS value is likely to have varied due to power variation caused by LAA bandwidth variation. The eNB may be able to compensate somewhat for the reported DRS value. For example, the eNB may compare the current reported value to the previous reported value, varying the current reported value by the change in LAA DRS transmission power. The eNB may determine the RRM and/or CSI.

[0066] Thus, the UE may assume that the transmission power for the

CRS and CSI-RS in the DRS is constant for RRM measurements under predetermined conditions. These conditions may include that the DRS is transmitted without any data loading or the eNB indicates in a network non- transparent manner that a nominal power DRS power level is used. In some embodiments, the eNB may signal a power level variation through explicit signaling. This signaling may be contemporaneous with the DRS or may be transmitted in the next subframe or DMTS after transmission of the DRS. The signaling may be a single bit to indicate that the DRS power level has been adjusted or is not the nominal DRS power level. In some embodiments, the signaling may include more than a single bit and indicate the amount of change from the nominal power level. The signaling may be broadcast in a system information broadcast (SIB) or other control signal that addresses the UEs in the cell.

[0067] In other embodiments, the eNB may not provide such an indication to the UE. Instead, the UE may be able to infer from other characteristics of the DRS transmission that the power level has changed. For example, the UE may infer that the DRS power level is consistent if the DRS signals are received essentially periodically, which may be an indication of few other devices using the LAA spectrum and thus the eNB broadcasting the DRS across a larger number of LAA channels. On the other hand, if the DRS transmissions are received randomly (sparsely), the UE may infer that a large number of other devices are occupying/using the LAA bandwidth and that the DRS have been transmitted over a narrow set of LAA frequencies. In this latter case, the UE may infer that the power of the DRS may have been increased by the eNB.

[0068] If the UE determines that the DRS power level is varying significantly, rather than the channel alone varying, in some embodiments the UE may only selectively report measurements of the DRS. The measurements reported may be those having a constant power level. If the measurement function is f(g) and the input of the function is the reference signal (RS) observed at time irs, then: m i_rs) = f(RS(i_rs))

[0069] where m() is the measured value. If the UE reports only measurements of reference signals with consistent power, the final reporting, mreport, can be made by instant measurement:

P [0070] where P is a set of indicators for constant reference power subframes and m(i_rs = 0) is always supposed to be reported.

[0071] Alternately, the report transmitted by the UE can be made by averaging all measurements. In other embodiments, the report transmitted by the UE can be made by averaging or weighting filtered observations of P. The averaging or weighting may be given by the function E():

^■report E ^' fTl(J,_{r 5}) , if t_rs G P

[0072] The application of an averaging filter may permit the UE measurements to fluctuate less and be more accurate. The averaging may be performed over a predetermined number of DRS measurements or may be variable, e.g., dependent on the change in DRS measurement from the last DRS measurement. The weighting of each previous DRS measurement may be dependent on the amount of variation of the previous DRS measurement from the average.

[0073] FIG. 6 illustrates a flow diagram of reference signal reporting in accordance with some embodiments. The reference signal reporting may be performed by any of the UEs shown in FIGS. 1-4 or described herein. As is apparent, a transmission (such as the DRS transmission) may be encoded for transmission at the source of the transmission and decoded at the receiver of the transmission.

[0074] At operation 602, the UE may receive and decode a DRS from the serving eNB. The DRS may be received on one or more LAA channels and may contain CRS and/or CSI-RS. DRS may be transmitted within a periodically occurring DMTC occasion that has a duration of 6 ms and a configurable period of 40, 80 or 160 ms. The transmission of the DRS on the LAA bands is also subject to LBT. A DL transmission burst containing a DRS without a PDSCH may follow a single idle observation interval of at least 25 μβ, the DRS, however may not be transmitted as frequently as scheduled due to the LBT. In some embodiments, the DRS may have further flexibility and can be transmitted by the network once in any subframe within the DMTC occasion. The UE may be configured with one or more CSI processes per serving cell by higher layers. Each CSI process may be associated with a CSI-RS resource and a CSI- interference measurement (CSI-IM) resource. Each CSI process may be configured with or without PMI/RI reporting by higher layer signaling and CSI reporting may be periodic or aperiodic. In some embodiments, the eNB may change the DRS sequence (e.g., a Zadoff-Chu sequence) depending on the DRS power level.

[0075] At operation 604, the UE may determine whether the DRS is a normal DRS, that is, a DRS transmitted by the eNB using a nominal power level. In some embodiments, the UE may wait to report the DRS until a sufficient amount of time to have received an indication from the eNB that indicates that the DRS was transmitted with an excessive power level. In some embodiments, the UE may determine the DRS level is abnormal inherently through

characteristics of the DRS, for example, the DRS measurement is randomly received or is significantly different from the previous DRS. The UE may store one or more previous DRS measurements to make such a determination. For example, the UE may determine whether the current measurement is outside one or two standard deviations from the previous measurement. This may, in some embodiments, be combined with knowledge of the UE mobility state (how fast the UE is moving) to determine whether it is likely that such a variation may have occurred under normal operation conditions or whether it is likely an artifact caused by power level variation.

[0076] At operation 606, if the UE determines that the DRS has been transmitted at a normal power level (or otherwise as below after adjustment), the UE may transmit the DRS measurement to the eNB. The measurement may be used by the eNB for handover (RRM) and channel condition (CSI/CSI-RS) determination. In some embodiments, the DRS measurement may include RSRP and/or RSRQ. The UE may transmit the measurement report using the LAA band at a fixed or relative subframe offset from the measurement instance or within a measurement window. The eNB may determine from the measurement whether handover to a different eNB (e.g., PCell or SCell, either of which may be a macro or micro eNB) is appropriate. The eNB may also determine whether to transition the UE to a different channel. [0077] At operation 608, if the UE determines that the DRS has been transmitted at an abnormal power level, the UE may determine whether to filter the DRS measurement. This is to say that the UE may determine whether or not the DRS measurements should be reported to the eNB.

[0078] At operation 610, the DRS measurement may be discarded by the

UE rather than being transmitted to the eNB. Alternatively, the UE may transmit a predetermined value outside of a normal range (e.g., 0) to indicate that the measurement report may be of an abnormal DRS.

[0079] At operation 612, instead of discarding the DRS measurement, the UE may adjust the DRS measurement. In particular, the UE may average the DRS measurement with a predetermined number of DRS measurements prior to reporting the DRS measurement at operation 606. In some embodiments, the averaging may occur for RRM measurements but not for CSI/CSI-RS measurements.

[0080] Examples

[0081] Example 1 is an apparatus of user equipment (UE), the apparatus comprising: an interface; and processing circuitry in communication with the interface and arranged to: decode a discovery reference signal (DRS) transmission from an evolved Node B (eNB) in an unlicensed band; determine whether a power level of the DRS transmission has varied from a nominal power level, the nominal power level used for transmission of a plurality of previously received DRS transmissions; in response to a determination that the power level of the DRS transmission is the nominal power level, generate a report for transmission to the eNB via the interface, the report comprising a DRS measurement for handover and channel state determination; and in response to a determination that the power level of the DRS transmission has varied from the nominal power level, perform an adjustment of at least one of the report or transmission of the report to the eNB.

[0082] In Example 2, the subject matter of Example 1 optionally includes, wherein: the adjustment of transmission of the report comprises the DRS measurement being discarded and transmission of the report being avoided. [0083] In Example 3, the subject matter of Example 2 optionally includes, wherein the processing circuitry is further configured to: generate reports for transmission to the eNB in the unlicensed band, the reports comprising DRS measurements for DRS transmissions in different Discovery Measurement Timing Configurations (DMTCs) and whose power transmissions are at the nominal power level, and refrain from generation of reports for DRS transmissions whose power transmissions vary from the nominal power level.

[0084] In Example 4, the subject matter of Example 3 optionally includes, wherein: the reports comprise radio resource management (RRM) measurements of the UE to a different eNB, and the processing circuitry is further configured to generate a channel state information (CSI) report comprising a CSI measurement of a channel state information reference signal (CSI-RS) transmission independent of the power level of an associated DRS transmission in the unlicensed band.

[0085] In Example 5, the subject matter of any one or more of Examples

1-4 optionally include, wherein: the adjustment of the report comprises alteration of the DRS measurement to create an altered DRS measurement prior to transmission of the DRS measurement to the eNB, the report comprising the altered DRS measurement.

[0086] In Example 6, the subject matter of Example 5 optionally includes, wherein: the alteration of the DRS measurement comprises determination of an average of the DRS measurement with a predetermined number of previous DRS measurements.

[0087] In Example 7, the subject matter of Example 6 optionally includes, wherein the processing circuitry is further configured to: determine whether the DRS measurement lies outside a predetermined number of standard deviations from an average value of the previous DRS measurements, and average the DRS measurement in response to a determination that the DRS measurement lies outside the predetermined number of standard deviations from the average value of the immediately previous DRS measurements.

[0088] In Example 8, the subject matter of any one or more of Examples

1-7 optionally include, wherein the processing circuitry is further configured to: determine, in response to reception from the eNB of an indication of a power level variation, that the power level of the DRS transmission in the unlicensed band has varied from the nominal power level.

[0089] In Example 9, the subject matter of any one or more of Examples

1-8 optionally include, wherein the processing circuitry is further configured to: determine, in response to an inference from characteristics of the DRS transmission in the unlicensed band, that the power level of the DRS transmission has varied from the nominal power level.

[0090] In Example 10, the subject matter of any one or more of

Examples 1-9 optionally include, wherein: the processing circuitry comprises a baseband processor, and the apparatus further comprises a transceiver configured to communicate with the eNB via the interface.

[0091] Example 11 is an apparatus of an evolved Node B (eNB), the apparatus comprising: an interface; and processing circuitry in communication with the interface and arranged to: determine whether to adjust a power level of a discovery reference signal (DRS) transmission; after determination of whether to adjust the power level of the DRS transmission, encode the DRS transmission for transmission to a user equipment (UE); and in response to a determination to adjust the power level of the DRS transmission and after transmission of the DRS transmission in an unlicensed band, decode one of a first DRS report from the UE comprising an adjusted DRS measurement or a second DRS report from the UE lacking a radio resource management (RRM) measurement based on the DRS transmission.

[0092] In Example 12, the subject matter of Example 11 optionally includes, wherein: the second DRS report comprises a channel state information (CSI) report comprising a CSI measurement of a channel state information reference signal (CSI-RS) transmission, the CSI report decoded independent of the power level of the DRS transmission.

[0093] In Example 13, the subject matter of any one or more of

Examples 11-12 optionally include, wherein: the adjusted DRS measurement comprises an average of a DRS measurement with a predetermined number of immediately previous DRS measurements in the unlicensed band.

[0094] In Example 14, the subject matter of Example 13 optionally includes, wherein: the adjusted DRS measurement is decoded when a DRS measurement of the DRS transmission in the unlicensed band lies outside a predetermined number of standard deviations from an average value of the immediately previous DRS measurements.

[0095] In Example 15, the subject matter of any one or more of Examples 11-14 optionally include, wherein the processing circuitry is further configured to: generate for transmission to the UE an indication of a power level variation of the DRS transmission in the unlicensed band.

[0096] In Example 16, the subject matter of Example 15 optionally includes, wherein: the indication comprises a single bit.

[0097] In Example 17, the subject matter of any one or more of

Examples 11-16 optionally include, wherein the processing circuitry is further configured to: alter a DRS sequence of the DRS transmission dependent on whether to adjust the power level of the DRS transmission.

[0098] In Example 18, the subject matter of any one or more of Examples 11-17 optionally include, wherein: the adjusted DRS measurement comprises a predetermined value outside of a normal range of values for a DRS measurement.

[0099] Example 19 is a computer-readable storage medium that stores instructions for execution by one or more processors, the one or more processors to: decode a discovery reference signal (DRS) transmission from an evolved Node B (eNB) in an unlicensed band; perform a DRS measurement of the DRS transmission; and dependent on a power level of the DRS transmission and the DRS measurement, one of: generate a first report for transmission to the eNB in the unlicensed band, the first report comprising an adjusted DRS measurement, or refrain from generation of the first report and refrain from generation of a second report for transmission to the eNB in the unlicensed band, the second report comprising the DRS measurement.

[00100] In Example 20, the subject matter of Example 19 optionally includes, wherein: the DRS measurement comprises a radio resource management (RRM) measurement to determine handover of the UE to the different eNB, and the instructions further configure the one or more processors to generate a channel state information (CSI) report comprising a CSI measurement of a channel state information reference signal (CSI-RS) transmission.

[00101] In Example 21, the subject matter of any one or more of

Examples 19-20 optionally include, wherein: the adjusted DRS measurement comprises an average of the DRS measurement with a predetermined number of immediately previous DRS measurements.

[00102] In Example 22, the subject matter of Example 21 optionally includes, wherein the instructions further configure the one or more processors to: average the DRS measurement in response to a determination that the DRS measurement lies outside a predetermined number of standard deviations from an average value of the immediately previous DRS measurements.

[00103] In Example 23, the subject matter of any one or more of

Examples 19-22 optionally include, wherein the instructions further configure the one or more processors to: determine that the power level of the DRS transmission has varied in response to reception from the eNB of an indication of a power level variation.

[00104] In Example 24, the subject matter of any one or more of

Examples 19-23 optionally include, wherein the instructions further configure the one or more processors to: determine that the power level of the DRS transmission has varied in response to an inference from characteristics of the DRS transmission.

[00105] Example 25 is a method of reporting reference signals, the method comprising: decoding a discovery reference signal (DRS) transmission from an evolved Node B (eNB) in an unlicensed band; performing a DRS measurement of the DRS transmission; and dependent on a power level of the DRS transmission and the DRS measurement, one of: generating a first report for transmission to the eNB in the unlicensed band, the first report comprising an adjusted DRS measurement, or refraining from generation of the first report and refraining from generation of a second report for transmission to the eNB in the unlicensed band, the second report comprising the DRS measurement.

[00106] In Example 26, the subject matter of Example 25 optionally includes, wherein: the DRS measurement comprises a radio resource management (RRM) measurement, and generating a channel state information (CSI) report comprising a CSI measurement of a channel state information reference signal (CSI-RS) transmission.

[00107] In Example 27, the subject matter of any one or more of

Examples 25-26 optionally include, wherein: the adjusted DRS measurement comprises an average of the DRS measurement with a predetermined number of immediately previous DRS measurements.

[00108] In Example 28, the subject matter of Example 27 optionally includes, further comprising: averaging the DRS measurement in response to a determination that the DRS measurement lies outside a predetermined number of standard deviations from an average value of the immediately previous DRS measurements.

[00109] In Example 29, the subject matter of any one or more of

Examples 25-28 optionally include, further comprising: determining that the power level of the DRS transmission has varied in response to reception from the eNB of an indication of a power level variation.

[00110] In Example 30, the subject matter of any one or more of

Examples 25-29 optionally include, further comprising: determining that the power level of the DRS transmission has varied in response to an inference from characteristics of the DRS transmission.

[00111] Example 31 is an apparatus of user equipment (UE), the apparatus comprising: means for decoding a discovery reference signal (DRS) transmission from an evolved Node B (eNB) in an unlicensed band; means for performing a DRS measurement of the DRS transmission; and dependent on a power level of the DRS transmission and the DRS measurement, one of: means for generating a first report for transmission to the eNB in the unlicensed band, the first report comprising an adjusted DRS measurement, or means for refraining from generation of the first report and means for refraining from generation of a second report for transmission to the eNB in the unlicensed band, the second report comprising the DRS measurement.

[00112] In Example 32, the subject matter of Example 31 optionally includes, wherein: the DRS measurement comprises a radio resource management (RRM) measurement, and the apparatus further comprises means for generating a channel state information (CSI) report comprising a CSI measurement of a channel state information reference signal (CSI-RS) transmission.

[00113] In Example 33, the subject matter of Example 32 optionally includes, wherein: the adjusted DRS measurement comprises an average of the DRS measurement with a predetermined number of immediately previous DRS measurements.

[00114] In Example 34, the subject matter of Example 33 optionally includes, further comprising: means for averaging the DRS measurement in response to a determination that the DRS measurement lies outside a predetermined number of standard deviations from an average value of the immediately previous DRS measurements.

[00115] In Example 35, the subject matter of any one or more of

Examples 32-34 optionally include, further comprising: means for determining that the power level of the DRS transmission has varied in response to reception from the eNB of an indication of a power level variation.

[00116] In Example 36, the subject matter of any one or more of

Examples 32-35 optionally include, further comprising: means for determining that the power level of the DRS transmission has varied in response to an inference from characteristics of the DRS transmission.

[00117] Although an embodiment has been described with reference to specific example embodiments, it will be evident that various modifications and changes may be made to these embodiments without departing from the broader scope of the present disclosure. Accordingly, the specification and drawings are to be regarded in an illustrative rather than a restrictive sense. The

accompanying drawings that form a part hereof show, by way of illustration, and not of limitation, specific embodiments in which the subject matter may be practiced. The embodiments illustrated are described in sufficient detail to enable those skilled in the art to practice the teachings disclosed herein. Other embodiments may be utilized and derived therefrom, such that structural and logical substitutions and changes may be made without departing from the scope of this disclosure. This Detailed Description, therefore, is not to be taken in a limiting sense, and the scope of various embodiments is defined only by the appended claims, along with the full range of equivalents to which such claims are entitled.

[00118] The subject matter may be referred to herein, individually and/or collectively, by the term "embodiment" merely for convenience and without intending to voluntarily limit the scope of this application to any single inventive concept if more than one is in fact disclosed. Thus, although specific embodiments have been illustrated and described herein, it should be appreciated that any arrangement calculated to achieve the same purpose may be substituted for the specific embodiments shown. This disclosure is intended to cover any and all adaptations or variations of various embodiments. Combinations of the above embodiments, and other embodiments not specifically described herein, will be apparent to those of skill in the art upon reviewing the above description.

[00119] In this document, the terms "a" or "an" are used, as is common in patent documents, to include one or more than one, independent of any other instances or usages of "at least one" or "one or more." In this document, the term "or" is used to refer to a nonexclusive or, such that "A or B" includes "A but not B," "B but not A," and "A and B," unless otherwise indicated. In this document, the terms "including" and "in which" are used as the plain-English equivalents of the respective terms "comprising" and "wherein." Also, in the following claims, the terms "including" and "comprising" are open-ended, that is, a system, UE, article, composition, formulation, or process that includes elements in addition to those listed after such a term in a claim are still deemed to fall within the scope of that claim. Moreover, in the following claims, the terms "first," "second," and "third," etc. are used merely as labels, and are not intended to impose numerical requirements on their objects.

[00120] The Abstract of the Disclosure is provided to comply with 37

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

Claims

CLAIMS What is claimed is:

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

an interface; and

processing circuitry in communication with the interface and arranged to: decode a discovery reference signal (DRS) transmission from an evolved Node B (eNB) in an unlicensed band;

determine whether a power level of the DRS transmission has varied from a nominal power level, the nominal power level used for transmission of a plurality of previously received DRS transmissions; in response to a determination that the power level of the DRS transmission is the nominal power level, generate a report for transmission to the eNB via the interface, the report comprising a DRS measurement for handover and channel state determination; and

in response to a determination that the power level of the DRS transmission has varied from the nominal power level, perform an adjustment of at least one of the report or transmission of the report to the eNB.

2. The apparatus of claim 1, wherein:

the adjustment of transmission of the report comprises the DRS measurement being discarded and transmission of the report being avoided.

3. The apparatus of claim 2, wherein the processing circuitry is further configured to:

generate reports for transmission to the eNB in the unlicensed band, the reports comprising DRS measurements for DRS transmissions in different Discovery Measurement Timing Configurations (DMTCs) and whose power transmissions are at the nominal power level, and

refrain from generation of reports for DRS transmissions whose power transmissions vary from the nominal power level.

4. The apparatus of claim 3, wherein:

the reports comprise radio resource management (RRM) measurements of the UE to a different eNB, and

the processing circuitry is further configured to generate a channel state information (CSI) report comprising a CSI measurement of a channel state information reference signal (CSI-RS) transmission independent of the power level of an associated DRS transmission in the unlicensed band.

5. The apparatus of claim 1, wherein:

the adjustment of the report comprises alteration of the DRS

measurement to create an altered DRS measurement prior to transmission of the DRS measurement to the eNB, the report comprising the altered DRS measurement.

6. The apparatus of claim 5, wherein:

the alteration of the DRS measurement comprises determination of an average of the DRS measurement with a predetermined number of previous DRS measurements.

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

determine whether the DRS measurement lies outside a predetermined number of standard deviations from an average value of the previous DRS measurements, and

average the DRS measurement in response to a determination that the DRS measurement lies outside the predetermined number of standard deviations from the average value of the immediately previous DRS measurements.

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

determine, in response to reception from the eNB of an indication of a power level variation, that the power level of the DRS transmission in the unlicensed band has varied from the nominal power level.

9. The apparatus of any one or more of claims 1-7, wherein the processing circuitry is further configured to:

determine, in response to an inference from characteristics of the DRS transmission in the unlicensed band, that the power level of the DRS

transmission has varied from the nominal power level.

10. The apparatus of any one or more of claims 1-7, wherein:

the processing circuitry comprises a baseband processor, and

the apparatus further comprises a transceiver configured to communicate with the eNB via the interface.

11. An apparatus of an evolved Node B (eNB), the apparatus comprising: an interface; and

processing circuitry in communication with the interface and arranged to: determine whether to adjust a power level of a discovery reference signal (DRS) transmission;

after determination of whether to adjust the power level of the DRS transmission, encode the DRS transmission for transmission to a user equipment (UE); and

in response to a determination to adjust the power level of the DRS transmission and after transmission of the DRS transmission in an unlicensed band, decode one of a first DRS report from the UE comprising an adjusted DRS measurement or a second DRS report from the UE lacking a radio resource management (RRM) measurement based on the DRS transmission.

12. The apparatus of claim 11, wherein:

the second DRS report comprises a channel state information (CSI) report comprising a CSI measurement of a channel state information reference signal (CSI-RS) transmission, the CSI report decoded independent of the power level of the DRS transmission.

13. The apparatus of claim 11 or 12, wherein:

the adjusted DRS measurement comprises an average of a DRS measurement with a predetermined number of immediately previous DRS measurements in the unlicensed band.

14. The apparatus of claim 13, wherein:

the adjusted DRS measurement is decoded when a DRS measurement of the DRS transmission in the unlicensed band lies outside a predetermined number of standard deviations from an average value of the immediately previous DRS measurements.

15. The apparatus of claim 11 or 12, wherein the processing circuitry is further configured to:

generate for transmission to the UE an indication of a power level variation of the DRS transmission in the unlicensed band.

16. The apparatus of 15, wherein:

the indication comprises a single bit.

17. The apparatus of claim 11 or 12, wherein the processing circuitry is further configured to:

alter a DRS sequence of the DRS transmission dependent on whether to adjust the power level of the DRS transmission.

18. The apparatus of claim 11 or 12, wherein:

the adjusted DRS measurement comprises a predetermined value outside of a normal range of values for a DRS measurement.

19. A computer-readable storage medium that stores instructions for execution by one or more processors, the one or more processors to:

decode a discovery reference signal (DRS) transmission from an evolved Node B (eNB) in an unlicensed band;

perform a DRS measurement of the DRS transmission; and dependent on a power level of the DRS transmission and the DRS measurement, one of:

generate a first report for transmission to the eNB in the unlicensed band, the first report comprising an adjusted DRS measurement, or

refrain from generation of the first report and refrain from generation of a second report for transmission to the eNB in the unlicensed band, the second report comprising the DRS measurement.

20. The medium of claim 19, wherein:

the DRS measurement comprises a radio resource management (RRM) measurement to determine handover of the UE to the different eNB, and

the instructions further configure the one or more processors to generate a channel state information (CSI) report comprising a CSI measurement of a channel state information reference signal (CSI-RS) transmission.

21. The medium of claim 19 or 20, wherein:

the adjusted DRS measurement comprises an average of the DRS measurement with a predetermined number of immediately previous DRS measurements.

22. The medium of claim 21, wherein the instructions further configure the one or more processors to:

average the DRS measurement in response to a determination that the DRS measurement lies outside a predetermined number of standard deviations from an average value of the immediately previous DRS measurements.

23. The medium of claim 19 or 20, wherein the instructions further configure the one or more processors to:

determine that the power level of the DRS transmission has varied in response to reception from the eNB of an indication of a power level variation.

24. The medium of claim 19 or 20, wherein the instructions further configure the one or more processors to:

determine that the power level of the DRS transmission has varied in response to an inference from characteristics of the DRS transmission.