RFID reader

Abstract

The device comprises: a receiving chain; a transmitting chain configured to generate a continuous wave (CW) radio frequency (RF) signal; and a directional coupler circuit configured to couple the CW RF signal to an antenna, wherein the directional coupler circuit is configured to couple a received RF signal based on the CW RF signal from the antenna to the receiving chain; and the receiving chain is configured to demodulate the received RF signal to recover RF identification (RFID) information from the received RF signal.

Description

Technology Field

[0001] Cross-reference to related applications

[0002] This patent application claims priority to pending U.S. Regular Application No. 18 / 390,684 filed December 20, 2023, which is assigned to the assignee of this application and is expressly incorporated by reference into this specification as fully described below and for all applicable purposes.

[0003] Technology field

[0004] The embodiments of the present disclosure generally relate to radio frequency identification (RFID), and more specifically, to RFID reader technology in wireless communication user equipment. Background Technology

[0005] An RFID system may include a passive RFID tag and an RFID reader. The RFID reader may transmit a continuous wave (CW) radio frequency (RF) signal to activate (e.g., power-up) the RFID tag. Once activated by the CW RF signal, the RFID tag may use a backscatter technique to transmit an information signal to the RFID reader (e.g., in response to a query from the RFID reader transmitted via the CW RF signal). Thus, the RFID reader may transmit CW RF signals to power up the RFID tag while simultaneously receiving data transmitted by the RFID tag.

[0006] The following presents a simplified overview of one or more implementations to provide a basic understanding of those implementations. This overview is not intended to be a comprehensive overview of all implementations considered, nor to identify the core or important elements of any of them, nor to define the scope of any or all of them. The sole purpose of this overview is to present some concepts of one or more implementations in a simplified form as an introduction to the more detailed descriptions provided below.

[0007] One aspect of the present disclosure relates to an apparatus. The apparatus comprises: a receiving chain; a transmitting chain configured to generate a continuous wave (CW) radio frequency (RF) signal; and a directional coupler circuit configured to couple the CW RF signal to an antenna, wherein the directional coupler circuit is configured to couple a received RF signal based on the CW RF signal from the antenna to the receiving chain; and the receiving chain is configured to demodulate the received RF signal to recover RF identification (RFID) information from the received RF signal.

[0008] Another aspect of the present disclosure relates to a method. The method comprises: generating a continuous wave (CW) radio frequency (RF) signal; coupling the CW RF signal to an antenna through a directional coupler circuit; configuring the directional coupler circuit to couple a received RF signal based on the CW RF signal from the antenna to a receiving chain; and demodulating the received RF signal to recover RF identification (RFID) information from the received RF signal.

[0009] Another aspect of the present disclosure relates to an apparatus. The apparatus comprises: means for generating a continuous wave (CW) radio frequency (RF) signal; directional coupler means for coupling the CW RF signal to an antenna; means for configuring the directional coupler means to couple a received RF signal based on the CW RF signal from the antenna to a receiving means; and means for demodulating the received RF signal to recover RF identification (RFID) information from the received RF signal.

[0010] To achieve the aforementioned purposes and related purposes, one or more embodiments include features that are sufficiently described below and specifically noted in the claims. The following description and accompanying drawings describe specific exemplary aspects of one or more embodiments in detail. However, these aspects represent only a very small part of the various ways in which principles of various embodiments may be employed and the described embodiments are intended to include all such aspects and their equivalents. Brief explanation of the drawing

[0011] FIG. 1 illustrates an exemplary wireless communication system according to one aspect of the present disclosure. FIG. 2 illustrates an exemplary RFID system according to another aspect of the present disclosure. FIG. 3 illustrates an exemplary RFID system including a device integrating an RFID reader circuit according to another aspect of the present disclosure. FIG. 4 illustrates an example of an RFID reader circuit portion of the device of FIG. 3 according to another aspect of the present disclosure. FIG. 5 illustrates a block diagram of an exemplary device programmed to provide RFID reader functionality according to another aspect of the present disclosure. FIG. 6 illustrates an example of a circuit section for transmitting a continuous wave (CW) signal and receiving a reflected backscattered signal and a component of the transmitted CW signal, according to another aspect of the present disclosure. FIG. 7a illustrates a block diagram of an exemplary device providing RFID reader functionality according to another aspect of the present disclosure. FIG. 7b illustrates an apparatus corresponding to the apparatus of FIG. 7a, which includes additional wide area network (WAN) communication components according to another aspect of the present disclosure. FIG. 8 illustrates a block diagram of an exemplary user device according to another aspect of the present disclosure. FIG. 9 illustrates a flow diagram of an exemplary RFID method according to another aspect of the present disclosure. FIG. 10 illustrates a flow diagram of another exemplary RFID method according to another aspect of the present disclosure. Specific details for implementing the invention

[0012] The detailed description below, in conjunction with the accompanying drawings, is intended to describe various configurations and is not intended to represent only the configurations in which the concepts described herein may be implemented. The detailed description includes specific details for the purpose of providing a thorough understanding of the various concepts. However, it will be apparent to those skilled in the art that these concepts may be implemented without these specific details. In some instances, widely known structures and components are illustrated in block diagram form to avoid obscuring such concepts.

[0013] Various aspects of the present disclosure relate to RFID communication. In some examples, user equipment operable within a wireless communication system may include RFID reader functionality.

[0014] FIG. 1 illustrates an exemplary wireless communication system (100) according to one aspect of the present disclosure. The wireless communication system (100) comprises three interacting domains: a core network (102), a wireless access network (RAN) (104), and a user equipment (UE) (106). By the wireless communication system (100), the UE (106) may be enabled to perform data communication with an external data network (110), such as (but not limited to) the Internet.

[0015] Additionally, the UE (106) may include an RFID reader function (122) capable of receiving RFID information from at least one RFID tag (e.g., RFID tag (124)). To this end, the UE (106) may transmit a continuous wave (CW) radio frequency (RF) signal capable of activating an RFID circuit on the RFID tag (124). Additionally, the UE (106) may demodulate and decode backscattered signals from the RFID tag (124) to recover RFID information modulated on backscattered signals by the RFID tag (124).

[0016] The RAN (104) may implement any suitable radio communication technology or technologies to provide radio access to the UE (106). As one example, the RAN (104) may operate according to the ETSI (European Telecommunications Standards Institute) GSM (Global System for Mobile Communications) specifications. As another example, the RAN (104) may operate according to the 3rd Generation Partnership Project (3GPP) New Radio (NR) specifications, often referred to as 5G. As an additional example, the RAN (104) may operate under a hybrid of 5G NR and eUTRAN (Evolved Universal Terrestrial Radio Access Network) standards, often referred to as Long Term Evolution (LTE). 3GPP refers to such a hybrid RAN as a Next Generation RAN or NG-RAN. In another example, the RAN (104) may operate according to both LTE and 5G NR standards. Of course, many other examples may be utilized within the scope of this disclosure.

[0017] As illustrated, the RAN (104) includes a plurality of base stations (108). Generally, a base station is a type of network entity in a wireless access network responsible for wireless transmission and reception to or from a UE in one or more cells. In different technologies, standards, or contexts, a base station may be referred to by those skilled in the art in various ways as a base transceiver station (BTS), wireless base station, wireless transceiver, transceiver function unit, basic service set (BSS), extended service set (ESS), access point (AP), node B (NB), e-node B (eNB), g-node B (gNB), transmit and receive point (TRP), disaggregated base station, or some other suitable technical term. In some examples, a base station may include two or more TRPs that may be juxtaposed or non-juxtaposed. Each TRP may communicate on the same or different carrier frequencies within the same or different frequency bands. In examples where the RAN (104) operates according to both LTE and 5G NR standards, one of the base stations (108) may be an LTE base station, while the other may be a 5G NR base station.

[0018] The wireless access network (104) supports wireless communication for multiple UEs or other devices. A UE may also be referred to by a person skilled in the art as a mobile station (MS), subscriber station, mobile unit, subscriber unit, wireless unit, remote unit, mobile device, wireless device, wireless communication device, remote device, mobile subscriber station, access terminal (AT), mobile terminal, wireless terminal, remote terminal, handset, terminal, user agent, mobile client, client, or any other suitable term.

[0019] The term UE broadly refers to a diverse array of devices and technologies. UEs may include a number of hardware structural components that are sized, shaped, and arranged to aid in communication; such components may include antennas, antenna arrays, RF chains, amplifiers, one or more processors, etc. that are electrically coupled to one another. For example, some non-limiting examples of mobile devices include mobile phones, cellular phones, smartphones, Session Initiation Protocol (SIP) phones, laptops, personal computers (PCs), notebooks, netbooks, smartbooks, tablets, personal digital assistants (PDAs), and a wide array of embedded systems corresponding to, for example, the Internet of Things (IoT).

[0020] Additionally, the UE may be integrated into or include automobiles or other transport vehicles, remote sensors or actuators, robots or robotic devices, satellite radios, Global Positioning System (GPS) devices, object tracking devices, remote control devices, consumer and / or wearable devices, such as eyeglasses, wearable cameras, virtual reality devices, smartwatches, health or fitness trackers, digital audio players (e.g., MP3 players), cameras, game consoles, etc. Additionally, the UE may be digital home or smart home devices such as home audio, video, and / or multimedia devices, home appliances, vending machines, intelligent lighting, home security systems, smart meters, etc. Additionally, the UE may be smart energy devices, security devices, solar panels or solar arrays, urban infrastructure devices controlling power (e.g., smart grids), lighting, water, etc., industrial automation and enterprise devices, logistics controllers, agricultural equipment, etc. Furthermore, the UE may provide connected medical or telemedicine support, i.e., remote healthcare. Telehealth devices may include telehealth monitoring devices and telehealth management devices, and the communication may be given priority processing or priority access over other types of information in terms of, for example, priority access for the transmission of important service data and / or related QoS for the transmission of important service data.

[0021] Wireless communication between the RAN (104) and the UE (106) may be described as utilizing an air interface. Transmissions over the air interface from a base station (e.g., base station (108)) to one or more UEs (e.g., UE (106)) may be referred to as downlink (DL) transmissions. In some examples, the term downlink may refer to a point-to-multipoint transmission originating from a base station (e.g., base station (108)). Another way to describe this point-to-multipoint transmission method may be to use the term broadcast channel multiplexing. Transmissions from a UE (e.g., UE (106)) to a base station (e.g., base station (108)) may be referred to as uplink (UL) transmissions. In some examples, the term uplink may refer to a point-to-point transmission originating from a UE (e.g., UE (106)).

[0022] In some examples, access to the air interface may be scheduled, where a scheduling entity of some other type of network entity (e.g., base station (108)) allocates resources for communication between some or all devices and equipment within the service area or cell. In the present disclosure, as further discussed below, the scheduling entity may be responsible for scheduling, assigning, reconfiguring, and releasing resources for one or more scheduled entities (e.g., UEs). That is, for scheduled communication, a plurality of UEs (106), which may be scheduled entities, may utilize resources allocated by the scheduling entity (e.g., base station (108)).

[0023] Base stations (108) are not the only entities that can function as scheduling entities. That is, in some examples, a UE may function as a scheduling entity that schedules resources for one or more scheduled entities (e.g., one or more other UEs). For example, UEs may communicate with other UEs in a peer-to-peer or device-to-device manner and / or in a repeater configuration.

[0024] As illustrated in FIG. 1, the base station (108) may broadcast downlink traffic (112) to one or more UEs (e.g., UE (106)). Generally, the base station (108) may be a node or device responsible for scheduling traffic in a wireless communication network, including downlink traffic (112), and in some examples, uplink traffic (116) and / or uplink control information (118) from one or more scheduled entities to a scheduling entity. Additionally, the base station (108) may be a node or device that receives downlink control information (114), including but not limited to scheduling information (e.g., grant), synchronization or timing information, or other control information, from another entity in the wireless communication network, such as a scheduling entity.

[0025] Uplink control information (118), downlink control information (114), downlink traffic (112), and / or uplink traffic (116) may be time-divided into frames, subframes, slots, and / or symbols. As used herein, a symbol may refer to a unit of time carrying one resource element (RE) per subcarrier in an orthogonal frequency division multiplexed (OFDM) waveform. A slot may, in some examples, carry a specific number of OFDM symbols. A subframe may refer to a specified duration (e.g., 1 millisecond (ms)). Multiple subframes or slots may be grouped together to form a single frame or radio frame. In this disclosure, a frame may refer to a predetermined duration for radio transmissions (e.g., 10 ms), and each frame is composed of, for example, 10 subframes each of 1 ms. Of course, these definitions are not mandatory, any suitable method for organizing waveforms may be utilized, and various time divisions of the waveforms may have any suitable duration.

[0026] Generally, each base station (108) may include a backhaul interface for communication with the backhaul (120) of a wireless communication system. The backhaul (120) may provide a link between the base station (108) and the core network (102). Additionally, in some examples, the backhaul network may provide interconnection between individual base stations (108). Various types of backhaul interfaces, such as direct physical connections, virtual networks, etc., may be employed using any suitable transmission network.

[0027] The core network (102) may be part of the wireless communication system (100) and may be independent of the wireless access technology used in the RAN (104). In some examples, the core network (102) may be configured according to ETSI standards, 3GPP standards, or any other suitable standard or configuration.

[0028] As mentioned above, the present disclosure relates to a UE comprising RFID reader functionality in some embodiments. RFID is used in a wide variety of applications, including, for example, identification devices, inventory tracking, assembly line processes, access control, etc.

[0029] FIG. 2 illustrates an exemplary RFID system (200) according to another aspect of the present disclosure. The RFID system (200) includes an RFID tag (202) and an RFID reader (204). In this example, the RFID tag (202) is a passive tag (e.g., does not include its own power source) and uses a backscatter technique to transmit information to the RFID reader (204).

[0030] The RFID reader (204) transmits a CW RF signal (206) that can be received by the RFID tag (202) when the RFID tag (202) and the RFID reader (204) are relatively close to each other. Generally, the operable distance is implementation-specific. The RFID tag (202) uses energy from the CW RF signal (206) to power a backscattering module (e.g., an energy reflection and modulation circuit) and thereby modulates information on the CW RF signal. Thus, the RFID tag (202) transmits a reflected signal (208) that is modulated along with the information. The RFID reader (204) includes a circuit for demodulating and decoding the reflected signal (208) to recover the information transmitted by the RFID tag (202).

[0031] RFID readers may be implemented in various types of devices. In some examples, RFID readers may be implemented in devices that support other forms of wireless communication.

[0032] FIG. 3 illustrates an exemplary RFID system (300) including a device (302) that integrates an RFID reader circuit according to another aspect of the present disclosure. The device (302) may be a UE or some other type of wireless communication device.

[0033] The device (302) includes an antenna (304), an RF front-end (RFFE) module (306), a transceiver (308), and a modem (310) that may be used to transmit wireless communication signals to other wireless communication devices and to receive wireless communication signals from other wireless communication devices.

[0034] The device (302) also includes a dedicated RFID reader circuit (312) used to read information from an RFID tag (314). The RFID reader circuit (312) generates a CW signal (316) that is transmitted through the antenna (304) as an over-the-air CW RF signal (318). In response to the over-the-air CW RF signal (318), the RFID tag (314) outputs a modulated over-the-air signal (320) that carries information to be read by the RFID reader circuit (312). The antenna (304) receives the over-the-air signal (320), and thereby, a corresponding modulated signal (322) (which may be referred to as a reflected signal) is provided to the RFID reader circuit (312) through the RFFE module (306).

[0035] FIG. 4 illustrates an example of an RFID reader circuit (312) of the device (302) of FIG. 3 according to another aspect of the present disclosure. The transmission chain of the RFID reader circuit (312) includes a digital-to-analog converter (DAC) (402) that converts information (e.g., query information) to be transmitted to an RFID tag into an analog signal. A filter (404) filters the analog signal to provide the filtered signal to a mixer (406). The mixer (406) upconverts the analog signal based on a signal from a local oscillator (LO) (408). An amplifier (410) amplifies the upconverted signal and provides the output signal to the RFFE module (306) of FIG. 3. The receiving chain of the RFID reader circuit (312) includes an adder circuit (412) that adds (or subtracts) the output of the vector modulator (414) to the received signal (426) (e.g., a reflected signal from the RFID tag (314) of FIG. 3 received from the RFFE module (306) via the antenna (304). A gain control circuit (416) adjusts the amplitude of the output of the adder circuit (412). A low-noise amplifier (LNA) (418) amplifies the output of the gain control circuit (416). A mixer (420) down-converts the amplified signal based on the signal from the local oscillator (408). A low-pass filter (422) filters the down-converted signal, and an analog-to-digital converter (ADC) (424) converts the analog-filtered signal into a digital signal to enable further processing (e.g., decoding) of the received signal.

[0036] For single-antenna RFID readers, CW signals transmitted by the RFID reader may leak to the receiver due to limited isolation of the circulator or directional coupler. These leaked signals may be referred to as self-jamming signals. The frequency of the self-jamming signal is close to the frequency of the useful reflected signal. Therefore, it may be difficult to remove the self-jamming signal from the received signal using a filter.

[0037] As shown in FIG. 3, the RFID reader circuit (312) may receive a CW leakage signal (324) (self-jamming signal) associated with the CW signal (316) due to, for example, return loss of the antenna (304) and / or other factors. The amplitude of the CW leakage signal (324) may be higher than the amplitude of the modulated signal (322) (reflected signal), thereby negatively affecting the decoding of the modulated signal (322).

[0038] For example, in scenarios where the power of the self-jamming signal is much greater than the useful reflected signal received by the RFID reader, the useful reflected signal will be completely drowned out by the self-jamming signal, which will result in receive (RX) saturation and reduced sensitivity. In this case, an RF front-end with a relatively high dynamic range may be employed to accurately distinguish the useful signals. However, the use of such an RF front-end may increase the complexity and cost of the device.

[0039] The backscattered signal may be an amplitude-shifted (ASM) version of the CW RF signal transmitted from the RFID reader. In this case, since the frequencies of the transmitted and received signals are the same, the phase noise of the self-jamming signal may limit the receiver's sensitivity. Therefore, the phase noise must be canceled using cancellation techniques to improve the operating range of the RFID reader.

[0040] In some examples, the implementation of a single-antenna RFID reader on a device (e.g., a UE such as a cell phone) may involve the use of additional hardware to eliminate self-jamming signals in order to achieve long-range targets (e.g., an RFID query range of more than 10 cm). In the example of FIG. 4, a vector modulator (414) and a summer circuit (412) are used to eliminate the CW leakage signal (324) from a received signal (426) (which includes both the modulated signal (322) and the CW leakage signal (324)). As illustrated, the vector modulator (414) generates a signal (428) (based on local oscillator feedback (430)) which may be added to or subtracted from the received signal (426) to eliminate part or all of the CW leakage signal (324).

[0041] The use of such dedicated RFID reader hardware (e.g., an RFID reader chip with a self-jamming signal canceller and an analog RF front-end) may increase the device's bill of materials (BOM) cost. Additionally, this RFID reader hardware may occupy valuable space on the device (e.g., which may be implemented on an integrated circuit).

[0042] The present disclosure relates to providing RFID technology on a device (e.g., a UE such as a cell phone) without any additional hardware overhead in some embodiments. For example, existing hardware of a device used for Wide Area Network (WAN) connectivity may be optionally repurposed to provide RFID functionality. In some examples (e.g., for previously deployed UEs), this may simply involve updating the software on the device. Adding RFID reader functionality to a device in this way may provide a low-cost, highly integrated handheld solution that expands industrial and consumer markets for such devices. Furthermore, such a solution can be enabled on existing UEs via a software update without any BOM costs.

[0043] FIG. 5 illustrates a block diagram of an exemplary device (502) programmed to provide RFID reader functionality according to another aspect of the present disclosure. The device (502) includes an antenna (504), an RF front-end (RFFE) module (506), a transceiver (508), and a modem (510) that may be used to transmit wireless communication signals to other wireless communication devices and to receive wireless communication signals from other wireless communication devices.

[0044] Additionally, the device (502) is programmed to provide RFID reader functionality using the existing hardware of the device (502). For example, the transmitting chain of the device (502) is used to generate a CW signal. Additionally, the receiving chain of the device (502) is used to remove self-jamming signal components from the received signal, demodulate the resulting signal, and decode information from the RFID tag embedded in the received signal. These and other embodiments of the device (502) will be described in more detail below with reference to FIGS. 6 and FIGS. 7.

[0045] FIG. 6 illustrates an example of a circuit section (600) for transmitting a continuous wave (CW) signal and receiving a reflected backscattered signal and a component of the transmitted CW signal, according to another aspect of the present disclosure. The circuit section (600) may be implemented on the RF side of a transceiver (not explicitly shown in FIG. 6).

[0046] The CW signal from the Tx output (602) of the transceiver is amplified by a power amplifier (604) and filtered by a surface acoustic wave (SAW) filter (606). The resulting CW output signal (608) is coupled to the antenna (610) by a directional coupler circuit (612). A simplified representation of the frequency spectrum of the transmitted CW (614) is shown at the bottom of FIG. 6. FIG. 6 and other figures may, for clarity, show signals carried by a signal line (e.g., where the signal line is shown as a solid line) as dashed lines drawn adjacent to the signal line.

[0047] The CW output signal (608) is transmitted through the antenna (610) as an over-the-air CW RF signal (616). In response to the over-the-air CW RF signal (616), the RFID tag (618) outputs a modulated over-the-air signal (620) (backscattered signal) that carries RFID information.

[0048] In this example, a single antenna (antenna (610)) is used to transmit a CW output signal (608) and to receive a modulated over-the-air signal (620) (backscattered signal). To enable the transceiver to receive this signal through the antenna (610), the directional coupler circuit (612) is configured in a reverse mode (reverse-coupled mode), and thereby, the signals received from the antenna in the directional coupler circuit (612) are coupled to the Rx input (622) of the transceiver (according to the reverse coupling factor of the directional coupler circuit (612). Thus, the corresponding backscattered signal (624) is provided to the Rx input (622) of the transceiver.

[0049] As discussed above, the CW leakage signal (626) associated with the CW output signal (608) may also be fed back to the Rx input (622) of the transceiver. For example, the CW leakage signal (626) may result from the return loss of the antenna (610) and / or imperfect isolation of the directional coupler circuit (612).

[0050] Accordingly, the composite signal may be received at an Rx input (622) containing both the backscattered signal (624) and the CW leakage signal (626). A simplified representation of the frequency spectrum of such a composite signal is shown at the top of FIG. 6. As indicated, the composite signal includes frequency components (628) due to the CW leakage signal (626) and frequency components (630) due to the backscattered signal (624). Exemplary operations of a transceiver regarding generating the CW signal and processing the corresponding received signal will be discussed with reference to FIG. 7a.

[0051] FIG. 7a illustrates a block diagram of an exemplary device (700) providing RFID reader functionality according to another aspect of the present disclosure. In this example, the device (700) includes the circuit section (600) of FIG. 6 and a transceiver (702). It should be recognized that the components of the device (700) may be implemented in different ways in different examples. For example, some of the components of the circuit section (600) may be implemented in the transceiver (702), or vice versa.

[0052] The transceiver (702) includes a transmission chain (704) and a reception chain (706). In some examples, the transceiver (702) may include other transmission and reception chains (not shown).

[0053] The transmission chain (704) includes a digital-to-analog converter (DAC) (708) that converts information to be transmitted to an RFID tag (e.g., query information) or other information into an analog signal. A filter (710) filters the analog signal to provide the filtered signal to a mixer (712). The mixer (712) upconverts the analog signal based on a signal (714) from a local oscillator (716). An amplifier (718) amplifies the upconverted signal (e.g., as discussed above in relation to FIG. 6) and provides a CW signal to be transmitted.

[0054] The receiving chain (706) includes a gain control circuit (720) that adjusts the amplitude of the received signal (e.g., the signal at the Rx input (622) discussed above in relation to FIG. 6). A low-noise amplifier (LNA) (722) amplifies the output of the gain control circuit (720). A mixer (724) downconverts the amplified signal based on the signal (726) from the local oscillator (716). Thus, in this example, the local oscillator (716) is shared by the transmitting chain (704) and the receiving chain (706). A low-pass filter (728) filters the downconverted signal, and an analog-to-digital converter (ADC) (730) converts the analog-filtered signal into a digital signal to enable further processing (e.g., decoding) of the received signal. For example, digital signal processing (not shown) may be able to extract RFID information from the signal by decoding an amplitude shift modulated (ASM) signal (or some other form of modulated signal).

[0055] The control circuit (732) may include the functionality to control the coupling mode of the directional coupler circuit (612). For example, when the RFID mode is invoked (e.g., when the user of the device activates an RFID application), the control circuit (732) may generate a control signal (734) that sets the directional coupler circuit (612) to a reverse mode (reverse coupled mode). In some examples, the control circuit (732) may be implemented as a component other than the transceiver (702). For example, a processor of the UE including the transceiver (702) may implement some or all of the functionality of the control circuit (732).

[0056] As mentioned above, in the example of FIG. 7a, the transmitting chain (704) and the receiving chain (706) may be configured to use the same local oscillator for individual up-conversion and down-conversion operations. This configuration may help to eliminate phase noise of the received signal as follows.

[0057] Using a transmit (Tx) chain phase lock loop (PLL) (e.g., local oscillator (716)) for the receive chain implies that the phase noise will be the same for the transmit path and the receive path. The CW signal may be characterized by Equation 1, and the CW leakage signal at the input to the receive chain mixer (e.g., mixer (724)) may be expressed by Equation 2.

[0058] Equation 1

[0059] Equation 2

[0060] Here, parameter “A” is a scaling factor for the amplitude of the received signal, and parameter “ " is phase noise, and parameter "α" is the phase difference between the transmission path and the reception path. The LO signals in the mixer (712) and the mixer (724) may be characterized by Equations 3 and 4, respectively.

[0061] Equation 3

[0062] Equation 4

[0063] Here, the parameter "τ" is the difference in delay between the transmitting and receiving local oscillator (LO) paths / routings (e.g., due to any differences in the paths associated with signals (714) and (726). In scenarios where the LO is shared and co-located with the transmitting mixer and the receiving mixer (e.g., located in the same area of ​​the integrated circuit), the parameter "τ" will be very small. In this case:

[0064] Equation 5

[0065] Consequently, phase noise will be eliminated at the output of the receiving chain mixer (e.g., mixer (724)). This elimination of phase noise results in an increase in the signal-to-noise ratio (SNR) of the received signal (after mixer (724)) in the presence of a strong self-jamming signal (at the Rx input (622)).

[0066] The following tables (divided into Tables 1 through 4 for convenience) illustrate simulated examples of query ranges (e.g., maximum usable distance between an RFID reader and an RFID tag) that may be achieved using the RFID reader technology described herein. The tables represent range estimates for RFID readers implemented without analog self-jamming signal cancellation (e.g., using a vector modulator). As indicated, a range of approximately 50 centimeters may be achieved without using dedicated RFID hardware (e.g., on a UE such as a cell phone).

[0067] The data in Tables 1 through 4 are based on the following assumptions. RFID links may be inherently unbalanced. Furthermore, since the RFID tag transmit power is determined by the RFID reader transmit power, the reverse link may be highly correlated with the forward link. The link budget is given by Equations 6 and 7, where Equation 6 is the maximum allowable loss for the forward link and Equation 7 is the maximum allowable loss for the reverse link.

[0068] Equation 6

[0069] Equation 7

[0070] In Equation 6, (dBm) = the transmission signal power supplied to the reader antenna; (dBi) = the reader's transmitting antenna gain; (dBi) = tag antenna gain and; (dB) = power loss due to backscatter modulation; (dBm) = Critical power required to power up the chip.

[0071] In Equation 7, (dB) = power reflection loss; (dB) = noise level; (dB) = minimum SNR to satisfy the given performance; (dBm) = thermal noise power; (dBm) = phase noise power of TX leakage.

[0072] [Table 1]

[0073]

[0074] [Table 2]

[0075]

[0076] [Table 3]

[0077]

[0078] [Table 4]

[0079]

[0080] FIG. 7b illustrates a device (700') corresponding to the device (700) of FIG. 7a, which includes additional wide area network (WAN) communication components according to another aspect of the present disclosure. The device (700') includes components of FIG. 7a, such as a transceiver (702') (corresponding to the transceiver (702) of FIG. 7a) which includes a transmission chain (704) and a reception chain (706). In the example of FIG. 7b, the device (700') also includes a reception chain (740). It should be recognized that the components of the device (700') may be implemented in different ways in different examples. For example, some of the components of the device (700') may be implemented in the transceiver (702'), or vice versa.

[0081] The receiving chain (740) includes a low-noise amplifier (LNA) (742) that amplifies the received signal (e.g., the signal at the Rx input (744)). A mixer (746) down-converts the amplified signal based on the signal from the local oscillator (748). A low-pass filter (750) filters the down-converted signal, and an analog-to-digital converter (ADC) (752) converts the analog-filtered signal into a digital signal to enable further processing (e.g., decoding) of the received signal.

[0082] When the device (700') is communicating with the WAN, the device (700') will use the transmission chain (704) for uplink transmission and the reception chain (740) for downlink reception. As illustrated in FIG. 7a, the device (700') includes switches (754) and switches (756) for selectively coupling the antenna (610) to the transmission chain (704) for transmission operations or to the reception chain (740) for reception operations. The control circuit (732) may include the functionality to generate a control signal (758) for controlling the switches (754) and switches (756). For example, during transmission operations, the control signal (758) may configure the switches (754) and switches (756) to couple the signal output by the power amplifier (604) to the antenna (610) through the directional coupler circuit (612). Conversely, during receiving operations, the control signal (758) may configure switches (754) and (756) to couple the signal received by the antenna (610) and output by the directional coupler circuit (612) to the Rx input (744).

[0083] FIG. 7b also illustrates various filters that may be used during transmission operations and / or reception operations. For example, filter (760) may be used to filter signals output by the power amplifier (604). Additionally, filter (762) may be used to filter signals provided to the Rx input (744). Furthermore, filter (764) may be used to filter both signals to be transmitted through the antenna (610) and signals received through the antenna (610).

[0084] As discussed above, the feedback (FB) Rx path (including the receiving chain (706)) may be used for RFID operations, digital pre-distortion (DPD) operations, Tx power measurements, antenna voltage standing wave ratio (VSWR) measurements, etc. To support RFID operations along with WAN operations (e.g., on shared resources), the device (700') may be configured to tune away from WAN operations when RFID operations need to be performed. For example, tune away may occur when there is a conflict and / or limitation of UE resources (e.g., RF hardware or modem hardware) among the wireless access technologies (RATs) used for WAN operations and RFID operations. When resource conflicts exist between RATs, some resources may be released based on one or more criteria (e.g., priority among RATs). In some concurrency scenarios involving UE resource limitations or conflicts (e.g., conflicting use of antennas, receive chain paths, VCOs, etc.), one or more transmit chains and / or receive chains may be released or tuned away.

[0085] As an example of a tune-away scenario, WAN data calls may be interrupted by artificial gaps. During each gap, the RF circuitry is tuned away to support activities for different Radio Access Technology (RAT). In some examples, a short tune-away may be approximately 6 milliseconds (ms) up to 130 ms. In some examples, a long tune-away may be as short as 10 ms, or up to several minutes or hours in length (e.g., for voice calls). In some examples, RFID readings require 10 ms to 200 ms, depending on the number of TAG reads per second. Therefore, an RFID operation may request a WAN tune-away to repurpose the WAN hardware to perform the RFID operation. Then, once the measurement is completed (e.g., depending on the requirement for the number of TAG reads per second), the WAN hardware can be released to continue the WAN operations. As another example, an RFID operation may request a WAN tune-away to repurpose the WAN hardware to perform an RFID operation for a specified time period (e.g., depending on the requirement for the number of TAG reads per second).

[0086] In some examples, the circuitry of FIGS. 6 and 7 may be implemented in a UE that originally did not include RFID reader functionality. For example, this circuitry may be used for power control measurements for cellular (e.g., WAN) communication, voltage standing wave ratio (VSWR) measurements for cellular communication, or for setting digital pre-distortion (DPD) parameters for cellular communication. In these scenarios, the directional coupler circuitry (612) may be configured in forward mode, thereby coupling a portion of the output signal back to the Rx input (622). For example, for power control and VSWR measurements, a receiver (not shown) may calculate the output transmit power based on a known coupling factor of the directional coupler circuitry (612) in forward mode. Then, the receiver may adjust the transmit power accordingly and / or calculate the antenna VSWR. As another example, for DPD processing, the transmitted signal (which may be distorted by the output stages of the transmitting chain) is fed back to the receiver and may be used to adjust the DPD of the transmitting chain. In some examples, the functionality (e.g., a receiving chain configured to operate with a single transmitter and directional coupler circuitry for measurement and DPD operations) may be referred to as a feedback receiver (FB Rx).

[0087] In these examples, the UE may be configured to provide RFID reader functionality by programming corresponding functionality into the UE. For example, the transmitting chain of the transceiver may be programmed to optionally generate a CW signal when an RFID operation is invoked on the UE. Additionally, the control circuit of the transceiver (or some other component of the UE) may be configured to generate a control signal to set the directional coupler circuit to reverse mode when an RFID operation is invoked on the UE. Furthermore, the receiving chain of the transceiver may be programmed to optionally eliminate phase noise from the received signal (e.g., by coupling the mixer (724) to the local oscillator (716) instead of the dedicated receiver local oscillator) and to demodulate and decode the resulting signal to extract RFID information when an RFID operation is invoked on the UE.

[0088] RFID readers as disclosed herein may be implemented in different ways in different examples. In some examples, the RFID reader may generate an ultra-high frequency (UHF) CW signal. For example, the CW signal may be transmitted over a frequency band defined within the UHF spectrum (e.g., 300 MHz to 1 GHz). In some examples, the CW signal may be transmitted over a GSM band (e.g., band 5 or band 8).

[0089] The directional coupler circuit may take different forms in different examples. In some examples, the directional coupler circuit may include a bidirectional coupler (or dual directional coupler) and a switch that selectively couples the coupler's forward output or reverse output to a receiving chain (e.g., under the control of a control signal).

[0090] In some examples, the RFID reader may be implemented in a device including an FB Rx receiver. In some examples, such an FB Rx receiver may be implemented within a transceiver (e.g., including one or more transmit chains and one or more receive chains). In some examples, such an FB Rx receiver may provide a relatively high dynamic range. For example, the FB Rx receiver may include an ADC having a relatively high sampling rate (e.g., up to 900 MHz).

[0091] In some examples, the transmission path uses a GSM power amplifier (e.g., for the power amplifier (604) in FIG. 6) to transmit a CW signal to an RFID tag. As discussed above, the directional coupler is configured in a reverse-coupled mode, allowing the same antenna to be used to transmit the CW signal and receive the backscattered signal from the RFID tag. Additionally, the reception path may use an FB Rx receiver to downconvert and demodulate the backscattered signal. In some examples, such an FB Rx receiver is designed to handle relatively high transmit (Tx) power coupled through the directional coupler. Depending on the Tx power level, the FB Rx gain can be adjusted to maximize the signal-to-noise ratio (SNR). Furthermore, the FB Rx can be configured to reuse the Tx PLL. Consequently, phase noise can be correlated and, consequently, canceled out, leading to better receiver sensitivity.

[0092] FIG. 8 illustrates a block diagram of an exemplary user device (800) according to another aspect of the present disclosure. The user device (800) may be a device configured to communicate wirelessly over a network as discussed in FIG. 1. The user device (800) may correspond to any of the UEs described herein.

[0093] According to various embodiments of the present disclosure, an element, or any part of an element, or any combination of elements may be implemented as a processing system (814). The processing system (814) may include one or more processors (referred to herein for convenience as processor (804)). Examples of processors (804) include microprocessors, microcontrollers, digital signal processors (DSPs), field programmable gate arrays (FPGAs), programmable logic devices (PLDs), state machines, gated logic, discrete hardware circuits, and other suitable hardware configured to perform the various functions described throughout the present disclosure. In various examples, user equipment (800) may be configured to perform any one or more of the functions described herein. That is, the processor (804) may be used to implement any one or more of the processes and procedures described herein, as utilized in user equipment (800).

[0094] In some cases, the processor (804) may be implemented via a baseband or modem chip, and in other implementations, the processor (804) itself may include a number of devices separate from or distinct from the baseband or modem chip (e.g., in such scenarios, these devices may work together to achieve the embodiments discussed herein). And as mentioned above, various hardware arrangements and components outside the baseband modem processor, including RF chains, power amplifiers, modulators, buffers, interleavers, adders / summers, etc., may be used in the implementations.

[0095] In this example, the processing system (814) may be implemented as a bus architecture, generally represented by the bus (802). The bus (802) may include any number of interconnect buses and bridges depending on the specific application and overall design constraints of the processing system (814). The bus (802) communicably couples various circuits together, including one or more processors (generally represented by the processor (804)), one or more memories (referred to herein for convenience as memory (805)), and one or more computer-readable media (generally represented by the computer-readable media (806)). The bus (802) may also link various other circuits, such as timing sources, peripherals, voltage regulators, and power management circuits, which are widely known in the art and therefore will not be further described. The bus interface (808) provides an interface between the bus (802), the transceiver (810), and the antenna array (820), and between the bus (802) and the interface (830). The transceiver (810) provides a means or communication interface for communicating with various other devices over a wireless transmission medium. The interface (830) provides a means or communication interface for communicating with various other devices and devices (e.g., user equipment (800) or other external devices and other devices housed within the same device) over an internal bus or an external transmission medium, such as an Ethernet cable. Depending on the nature of the device, the interface (830) may include a user interface (e.g., a keypad, a display, a speaker, a microphone, a joystick). Of course, such a user interface is optional and may be omitted in some examples, such as IoT devices.

[0096] The processor (804) is responsible for general processing, including managing the bus (802) and executing software stored on the computer-readable medium (806). When executed by the processor (804), the software causes the processing system (814) to perform various functions described below for any specific device. The computer-readable medium (806) and memory (805) may also be used to store data that is manipulated by the processor (804) when the software is executed. For example, memory (805) may store RFID information (815) (e.g., RFID parameters) used by the processor (804) for the communication operations described herein.

[0097] One or more processors (804) in the processing system may execute software. Software will be broadly interpreted to mean instructions, instruction sets, code, code segments, program code, programs, subprograms, software modules, applications, software applications, software packages, routines, subroutines, objects, executables, execution threads, procedures, functions, etc., whether or not referred to as software, firmware, middleware, microcode, hardware description language, or others. Software may reside on a computer-readable medium (806).

[0098] The computer-readable medium (806) may be a non-transient computer-readable medium. A non-transient computer-readable medium includes, for example, a magnetic storage device (e.g., a hard disk, a floppy disk, a magnetic strip), an optical disk (e.g., a compact disc (CD) or a digital multifunction disc (DVD)), a smart card, a flash memory device (e.g., a card, a stick, or a key drive), random access memory (RAM), read-only memory (ROM), programmable ROM (PROM), erasable PROM (EPROM), electrically erasable PROM (EEPROM), a register, a removable disk, and any other suitable medium for storing software and / or instructions that may be accessed and read by a computer. The computer-readable medium (806) may reside within the processing system (814), may be outside the processing system (814), or may be distributed across multiple entities including the processing system (814). The computer-readable medium (806) may be implemented in a computer program product. For example, a computer program product may include a computer-readable medium in the packaging materials. Those skilled in the art will recognize a method to best realize the described functionality presented throughout this disclosure by relying on the overall design constraints imposed on the entire system and the specific application.

[0099] The user equipment (800) may be configured to perform one or more of the operations described herein (e.g., as described above in connection with FIGS. 1 through 7 and as described below in connection with FIGS. 9 and 10). In some embodiments of the present disclosure, a processor (804) utilized in the user equipment (800) may include circuits configured for various functions.

[0100] In some embodiments of the present disclosure, the processor (804) may include a communication and processing circuit (841). The communication and processing circuit (841) may be configured to communicate with a base station. The communication and processing circuit (841) may include one or more hardware components that provide a physical structure for performing various processes related to communication (e.g., receiving a signal and / or transmitting a signal) as described herein. The communication and processing circuit (841) may further include one or more hardware components that provide a physical structure for performing various processes related to signal processing (e.g., processing a received signal and / or processing a signal for transmission) as described herein. The communication and processing circuit (841) may additionally be configured to execute communication and processing software (851) contained on a computer-readable medium (806) to implement one or more functions described herein.

[0101] In some implementations where communication involves receiving information, the communication and processing circuit (841) may obtain information from a component of the user equipment (800) (e.g., from a transceiver (810) that receives information via radio frequency signaling or some other type of signaling suitable for an applicable communication medium), process the information (e.g., decode), and output the processed information. For example, the communication and processing circuit (841) may output information to another component of the processor (804), to memory (805), or to a bus interface (808). In some examples, the communication and processing circuit (841) may receive one or more of signals, messages, other information, or any combination thereof. In some examples, the communication and processing circuit (841) may receive information through one or more channels. In some examples, the communication and processing circuit (841) may receive one or more of signals, messages, SCIs, feedback, other information, or any combination thereof. In some examples, the communication and processing circuit (841) and / or the transceiver (810) may include functionality for means for receiving. In some examples, the communication and processing circuit (841) may include functionality for means for decoding. In some examples, the communication and processing circuit (841) may include functionality for means for receiving information from a network entity.

[0102] In some implementations where communication involves transmitting information (e.g., sending), the communication and processing circuit (841) may obtain information (e.g., from a processor (804), memory (805), or other component of a bus interface (808), process the information (e.g., encoding), and output the processed information. For example, the communication and processing circuit (841) may output information to a transceiver (810) (e.g., transmitting information via radio frequency signaling or some other type of signaling suitable for an applicable communication medium). In some examples, the communication and processing circuit (841) may transmit one or more of signals, messages, other information, or any combination thereof. In some examples, the communication and processing circuit (841) may transmit information through one or more channels. In some examples, the communication and processing circuit (841) may transmit one or more of signals, messages, SCIs, feedback, other information, or any combination thereof. In some examples, the communication and processing circuit (841) and / or transceiver (810) may include functionality for means for transmitting. In some examples, the communication and processing circuit (841) may include functionality for means for encoding. In some examples, the communication and processing circuit (841) may include functionality for means for transmitting information to a network entity.

[0103] The processor (804) may include an RFID configuration circuit (842) configured to perform RFID configuration-related operations as discussed herein. The RFID configuration circuit (842) may be configured to execute RFID configuration software (852) included on a computer-readable medium (806) to implement one or more functions described herein.

[0104] The RFID configuration circuit (842) may include functionality for means for configuring a transmission chain and / or a reception chain. For example, in response to a call from an RFID application (e.g., by a user of the user equipment (800)), the RFID configuration circuit (842) may configure a transmission chain to generate a CW signal and configure a reception chain to use the same local oscillator as the transmission chain.

[0105] The RFID configuration circuit (842) may include functionality for means for configuring a directional coupler. For example, in response to a call from an RFID application (e.g., by a user of the user equipment (800)), the RFID configuration circuit (842) may generate a control signal for configuring a directional coupler circuit in reverse mode.

[0106] The RFID configuration circuit (842) may include functionality for means to temporarily disable or enable communication. For example, in response to a call to an RFID application (e.g., by a user of the user equipment (800)), the RFID configuration circuit (842) may temporarily disable cellular communication (e.g., WAN transmissions). As another example, in response to the termination of an RFID process (e.g., successful reading of an RFID tag), the RFID configuration circuit (842) may re-enable cellular communication (e.g., WAN transmissions).

[0107] The processor (804) may include an RFID processing circuit (843) configured to perform RFID processing-related operations as discussed herein. The RFID processing circuit (843) may be configured to execute RFID processing software (853) included on a computer-readable medium (806) to implement one or more functions described herein.

[0108] The RFID processing circuit (843) may include functionality for means for performing RFID processing operations. For example, the RFID processing circuit (843) may include functionality for means for demodulation and / or decoding. As an example, the RFID processing circuit (843) may demodulate and / or decode a received signal to recover RFID information (e.g., any type of information transmitted from an RFID tag) from the signal.

[0109] The RFID processing circuit (843) may include functionality for means to perform a Clear Channel Assessment (CCA). For example, the RFID processing circuit (843) may cooperate with the communication and processing circuit (841) and the transceiver (810) to monitor a specific frequency band and determine whether any energy detected on the frequency band exceeds a CCA threshold.

[0110] The RFID processing circuit (843) may include functionality for means for initiating RFID operations. For example, the RFID processing circuit (843) may initiate RFID transmission and reception operations when the CCA indicates that the channel is available.

[0111] FIG. 9 illustrates a flow diagram of an exemplary RFID method according to another aspect of the present disclosure. As described below, some or all of the illustrated features may be omitted in a particular implementation within the scope of the present disclosure, and some of the illustrated features may not be required for the implementation of all examples. In some examples, the method (900) (e.g., a method for wireless communication) may be performed by the user equipment (800) illustrated in FIG. 8 or other wireless communication device. In some examples, the method (900) may be performed by any suitable device or means for performing the functions or algorithms described herein.

[0112] In block 902, a device (e.g., user equipment (800) or other device) may generate a continuous wave (CW) radio frequency (RF) signal. Exemplary means for generating a CW RF signal may include any of the transmission chains, transmitters, transceivers, or related circuits described herein. For example, an RFID configuration circuit (842) may configure a transmission chain to generate a CW signal.

[0113] In block 904, the device may couple a CW RF signal to an antenna through a directional coupler circuit. Exemplary means for coupling a CW RF signal to an antenna through a directional coupler circuit may include any of the transmission chains, transmission paths, RFFEs, RF circuits, or related circuits described herein. For example, an RFID configuration circuit (842) may configure a transmission chain to couple its output to a directional coupler circuit (e.g., via a switch). As another example, the transmission chain may be directly connected to a directional coupler circuit so that the CW RF signal is coupled to an antenna through the directional coupler circuit.

[0114] In block 906, the device may configure a directional coupler circuit to couple a received RF signal based on a CW RF signal from an antenna to a receiving chain. Exemplary means for configuring a directional coupler circuit to couple a received RF signal based on a CW RF signal from an antenna to a receiving chain may include any of the control circuits, transmission chains, transmission paths, transceivers, processors, or related circuits described herein. For example, the RFID configuration circuit (842) may generate a control signal to configure the directional coupler circuit in reverse mode. As another example, the device's control circuit may generate a control signal to configure the directional coupler circuit in reverse mode.

[0115] In block 908, the device may demodulate a received RF signal to recover RF identification (RFID) information from the received RF signal. Exemplary means for demodulating a received RF signal to recover RF identification (RFID) information from the received RF signal may include any of the receiving chains, transceivers, processors, or related circuitry described herein. For example, an RFID processing circuitry (843) may demodulate a received signal to recover RFID information from the signal. As another example, a transceiver of the device may demodulate a received signal to recover RFID information from the signal.

[0116] In some examples, the device may generate a control signal to configure a directional coupler circuit in reverse mode for an RFID operation mode. In some examples, the device may generate a control signal to configure a directional coupler circuit in forward mode for a power control measurement operation mode for cellular (e.g., WAN) communication or a voltage standing wave ratio (VSWR) measurement operation mode for cellular communication.

[0117] In some examples, the received RF signal may include an amplitude-shifted modulated reflection of the CW RF signal. In some examples, the device may perform amplitude-shifted demodulation of the received RF signal.

[0118] In some examples, the received RF signal may include a first component and a second component. In some examples, the first component may include phase noise resulting from leakage of the CW RF signal in the receiving chain. In some examples, the second component may include an amplitude-shifted modulated signal based on the CW RF signal. In some examples, the device may subtract the first component from the received RF signal and recover RFID information from the amplitude-shifted modulated signal.

[0119] In some examples, the device may generate a CW RF signal from a local oscillator signal. In some examples, the device may use the local oscillator signal to downconvert the received RF signal. In some examples, the device may multiply the local oscillator signal by the received RF signal to recover RFID information.

[0120] In some examples, the device may optionally configure the transmit chain and the receive chain to operate in a first operation mode associated with RFID communication or in a second operation mode associated with cellular communication. In some examples, the device may configure the transmit chain to generate a CW RF signal in the first operation mode associated with RFID communication. In some examples, the device may configure the transmit chain to generate first information signals intended for a network entity of a wireless communication network in the second operation mode associated with cellular communication. In some examples, the device may configure the receive chain to demodulate a received RF signal to recover RFID information in the first operation mode associated with RFID communication. In some examples, the device may configure the receive chain (or another receive chain) to receive second information signals from a network entity in the second operation mode associated with cellular communication.

[0121] In some examples, the device may configure the receiving chain to perform a Clear Channel Evaluation (CCA) procedure for the RF channel. In some examples, the device may configure the transmitting chain to transmit a CW RF signal in response to a CCA procedure indicating that the RF channel is available for use.

[0122] In some examples, the device may generate a CW RF signal for transmission over the ultra-high frequency (UHF) band. In some examples, the device may monitor the UHF band for the received RF signal. In some examples, the UHF band may include the GSM (global system for mobile communications) band. In some examples, the UHF band may include a frequency range of 800 megahertz (MHz) to 1 gigahertz (GHz).

[0123] FIG. 10 illustrates a flow diagram of another exemplary RFID method according to another aspect of the present disclosure. As described below, some or all of the illustrated features may be omitted in a particular implementation within the scope of the present disclosure, and some of the illustrated features may not be required for the implementation of all examples. In some examples, the method (1000) (e.g., a method for wireless communication) may be performed by the user equipment (800) illustrated in FIG. 8 or other wireless communication device. In some examples, the method (1000) may be performed by any suitable device or means for performing the functions or algorithms described herein.

[0124] In block 1002, the device (e.g., user equipment (800) or other device) may enable RFID mode. Exemplary means for enabling RFID mode may include any of the processors or related circuits described herein. For example, the RFID processing circuit (843) may provide an application that enables the user of the device to enable RFID mode.

[0125] In block 1004, the device temporarily disables cellular (e.g., WAN) communication. Exemplary means for temporarily disabling cellular communication may include any of the processors or related circuits described herein. For example, in response to the activation of RFID mode, the RFID configuration circuit (842) may temporarily disable cellular communication (e.g., GSM transmissions). In certain scenarios, the device may support the simultaneous operation of the WAN and RFID by sharing resources. For example, a WAN operating in higher frequency bands may operate simultaneously with the RFID. When the WAN requests the feedback receiving path to perform transmission (Tx) measurements, the RFID operation may be suspended for that duration and may be resumed later when the WAN completes the requested measurements through the feedback receiving path.

[0126] In block 1006, the device may perform a clear channel evaluation. Exemplary means for performing a clear channel evaluation may include any of the receiving chains, transceivers, processors, or related circuits described herein. For example, the RFID processing circuit (843) may work in cooperation with the communication and processing circuit (841) and the transceiver (810) to monitor a specific frequency band and determine whether any energy detected on the frequency band exceeds a CCA threshold.

[0127] In block 1008, the device may initiate RFID transmit and receive operations when a clear channel evaluation indicates that a channel is available. Exemplary means for initiating RFID transmit and receive operations may include any of the processors or related circuits described herein. For example, an RFID configuration circuit (842) and / or an RFID processing circuit (843) may initiate RFID transmit and receive operations when a CCA indicates that a channel is available.

[0128] In block 1010, the device re-enables cellular communication upon completion of RFID operations. Exemplary means for re-enabled cellular communication upon completion of RFID operations may include any of the processors or related circuits described herein. For example, in response to the termination of an RFID process (e.g., successful reading of an RFID tag), the RFID configuration circuit (842) may re-enable cellular communication (e.g., GSM transmissions).

[0129] Referring again to FIG. 8, in one configuration, user equipment (800) comprises means for generating a continuous wave (CW) radio frequency (RF) signal; directional coupler means for coupling the CW RF signal to an antenna; means for configuring the directional coupler means to couple a received RF signal based on the CW RF signal from the antenna to a receiving means; and means for demodulating the received RF signal to recover RF identification (RFID) information from the received RF signal. In one embodiment, the aforementioned means may be a processor (804) illustrated in FIG. 8 configured to perform the functions described by the aforementioned means (e.g., as discussed above). In another embodiment, the aforementioned means may be a circuit or any device configured to perform the functions described by the aforementioned means (e.g., as described herein together with FIG. 1 through 7, FIG. 9, and FIG. 10).

[0130] The following provides an overview of the embodiments of the present disclosure:

[0131] Aspect 1: The device comprises: a receiving chain; a transmitting chain configured to generate a continuous wave (CW) radio frequency (RF) signal; and a directional coupler circuit configured to couple the CW RF signal to an antenna, wherein the directional coupler circuit is configured to couple a received RF signal based on the CW RF signal from the antenna to the receiving chain; and the receiving chain is configured to demodulate the received RF signal to recover RF identification (RFID) information from the received RF signal.

[0132] Embodiment 2: The device of Embodiment 1 further includes a control circuit configured to output a control signal for configuring a directional coupler circuit in reverse mode for an RFID operation mode.

[0133] Embodiment 3: In the device of Embodiment 2, the control circuit is further configured to output a control signal for configuring a directional coupler circuit in a forward mode for a power control measurement operation mode for cellular communication or a voltage standing wave ratio (VSWR) measurement operation mode for cellular communication.

[0134] Embodiment 4: In any one of Embodiments 1 to 3, the received RF signal comprises an amplitude-shift modulated reflection of a CW RF signal; and the receiving chain is further configured to perform amplitude-shift demodulation of the received RF signal.

[0135] Embodiment 5: In any one of Embodiments 1 to 4, the received RF signal comprises a first component and a second component; the first component comprises phase noise resulting from leakage of the CW RF signal in the receiving chain; the second component comprises an amplitude-shifted modulated signal based on the CW RF signal; and the receiving chain is further configured to subtract the first component from the received RF signal and recover RFID information from the amplitude-shifted modulated signal.

[0136] Embodiment 6: In any one of Embodiments 1 to 5, the apparatus further comprises a local oscillator, wherein the first mixer of the transmitting chain generates a CW RF signal from a first signal output by the local oscillator; and the second mixer of the receiving chain downconverts the received RF signal using the first signal output by the local oscillator.

[0137] Embodiment 7: In the device of Embodiment 6, the receiving chain is further configured to multiply a first signal output by a local oscillator and a received RF signal to recover RFID information.

[0138] Embodiment 8: In any one of Embodiments 6 to 7, the local oscillator, the transmitting chain, and the receiving chain are located on the same-location on the integrated circuit.

[0139] Embodiment 9: Any one of Embodiments 1 to 8 further includes a control circuit configured to selectively configure a transmitting chain and a receiving chain to operate in a first operating mode associated with RFID communication or in a second operating mode associated with cellular communication.

[0140] Embodiment 10: In the apparatus of Embodiment 9, in a first operation mode associated with RFID communication, the transmitting chain is further configured to generate a CW RF signal; in a second operation mode associated with cellular communication, the transmitting chain is further configured to generate first information signals intended for a network entity of a wireless communication network; in a first operation mode associated with RFID communication, the receiving chain is further configured to demodulate the received RF signal to recover RFID information; and in a second operation mode associated with cellular communication, the other receiving chain is configured to receive second information signals from the network entity.

[0141] Embodiment 11: Any one of Embodiments 1 to 10 further comprises a control circuit, the control circuit being configured to form a receiving chain to perform a Clear Channel Assessment (CCA) procedure for an RF channel; and a transmitting chain to form a transmitting chain to transmit a CW RF signal in response to a CCA procedure indicating that the RF channel is available for use.

[0142] Embodiment 12: In any one of Embodiments 1 to 11, the transmitting chain is further configured to generate a CW RF signal for transmission over an ultra-high frequency (UHF) band; and the receiving chain is further configured to monitor the UHF band for the received RF signal.

[0143] Embodiment 13: In the device of Embodiment 12, the UHF band includes the GSM (global system for mobile communications) band.

[0144] Embodiment 14: In the device of Embodiment 12, the UHF band includes a frequency range of 800 megahertz (MHz) to 1 gigahertz (GHz).

[0145] Embodiment 15: In any one of Embodiments 1 to 14, the device comprises a feedback receiver (FB Rx) including a receiving chain.

[0146] Embodiment 16: In any one of Embodiments 1 to 15, the device is configured as user equipment for cellular communication.

[0147] Aspect 17: The method comprises the steps of: generating a continuous wave (CW) radio frequency (RF) signal; coupling the CW RF signal to an antenna through a directional coupler circuit; configuring the directional coupler circuit to couple a received RF signal based on the CW RF signal from the antenna to a receiving chain; and demodulating the received RF signal to recover RF identification (RFID) information from the received RF signal.

[0148] Embodiment 18: The method of Embodiment 17 further includes the step of generating a control signal to configure a directional coupler circuit in reverse mode for an RFID operation mode.

[0149] Embodiment 19: The method of Embodiment 18 further includes the step of generating a control signal for configuring a directional coupler circuit in a forward mode for a power control measurement operation mode for cellular communication or a voltage standing wave ratio (VSWR) measurement operation mode for cellular communication.

[0150] Embodiment 20: In any one of the methods of Embodiments 17 to 19, the received RF signal comprises an amplitude-shift modulated reflection of a CW RF signal; the method further comprises the step of performing amplitude-shift demodulation of the received RF signal.

[0151] Aspect 21: In the method of Aspect 20, the received RF signal comprises a first component and a second component; the first component comprises phase noise resulting from leakage of a CW RF signal in the receiving chain; the second component comprises an amplitude-shifted modulated signal based on the CW RF signal; the method further comprises the step of subtracting the first component from the received RF signal and recovering RFID information from the amplitude-shifted modulated signal.

[0152] Aspect 22: Any one of Aspects 17 to 21 further comprises the step of generating a CW RF signal from a local oscillator signal; and the step of downconverting a received RF signal using the local oscillator signal.

[0153] Aspect 23: The method of Aspect 22 further includes the step of multiplying a local oscillator signal and a received RF signal to recover RFID information.

[0154] Aspect 24: Any one of Aspects 17 to 23 further comprises the step of optionally configuring a transmitting chain and a receiving chain to operate in a first operating mode associated with RFID communication or in a second operating mode associated with cellular communication.

[0155] Aspect 25: The method of Aspect 24 further comprises the steps of: configuring a transmission chain to generate a CW RF signal in a first operation mode associated with RFID communication; configuring a transmission chain to generate first information signals intended for a network entity of a wireless communication network in a second operation mode associated with cellular communication; configuring a reception chain to demodulate a received RF signal to recover RFID information in a first operation mode associated with RFID communication; and configuring a reception chain to receive second information signals from a network entity in a second operation mode associated with cellular communication.

[0156] Aspect 26: Any one of Aspects 17 to 25 further comprises the step of configuring a receiving chain to perform a Clear Channel Assessment (CCA) procedure on an RF channel; and the step of configuring a transmitting chain to transmit a CW RF signal in response to a CCA procedure indicating that the RF channel is available for use.

[0157] Aspect 27: Any one of Aspects 17 to 26 further comprises the step of generating a CW RF signal for transmission over an ultra-high frequency (UHF) band; and the step of monitoring the UHF band for the received RF signal.

[0158] Aspect 28: In the method of Aspect 27, the UHF band includes the GSM (global system for mobile communications) band.

[0159] Embodiment 29: In the method of Embodiment 27, the UHF band includes a frequency range of 800 megahertz (MHz) to 1 gigahertz (GHz).

[0160] Aspect 30: The device comprises means for generating a continuous wave (CW) radio frequency (RF) signal; directional coupler means for coupling the CW RF signal to an antenna; means for configuring the directional coupler means to couple a received RF signal based on the CW RF signal from the antenna to a receiving means; and means for demodulating the received RF signal to recover RF identification (RFID) information from the received RF signal.

[0161] The foregoing description of the present disclosure is provided to enable those skilled in the art to manufacture or use the present disclosure. Various modifications to the present disclosure will be readily apparent to those skilled in the art, and the general principles defined herein may be applied to other modifications without departing from the spirit or scope of the present disclosure. Accordingly, the present disclosure is not intended to be limited to the examples described herein and should be given the broadest scope consistent with the principles and novel features disclosed herein.

Claims

Claim 1 A device comprising: a receiving chain; a transmitting chain configured to generate a continuous wave (CW) radio frequency (RF) signal; and a directional coupler circuit configured to couple the CW RF signal to an antenna, wherein the directional coupler circuit comprises the directional coupler circuit, which is configured to couple a received RF signal based on the CW RF signal from the antenna to the receiving chain; and wherein the receiving chain is configured to demodulate the received RF signal to recover RF identification (RFID) information from the received RF signal. Claim 2 A device according to claim 1, further comprising a control circuit configured to output a control signal for configuring the directional coupler circuit in a reverse mode for an RFID operation mode. Claim 3 A device according to paragraph 2, wherein the control circuit is further configured to output the control signal for configuring the directional coupler circuit in a forward mode for a power control measurement operation mode for cellular communication or a voltage standing wave ratio (VSWR) measurement operation mode for cellular communication. Claim 4 A device according to claim 1, wherein the received RF signal comprises an amplitude-shift modulated reflection of the CW RF signal; and the receiving chain is further configured to perform amplitude-shift demodulation of the received RF signal. Claim 5 A device according to claim 1, wherein the received RF signal comprises a first component and a second component; the first component comprises phase noise resulting from leakage of the CW RF signal in the receiving chain; the second component comprises an amplitude-shifted modulated signal based on the CW RF signal; and the receiving chain is further configured to subtract the first component from the received RF signal and recover the RFID information from the amplitude-shifted modulated signal. Claim 6 An apparatus according to claim 1, further comprising a local oscillator, wherein a first mixer of the transmitting chain generates the CW RF signal from a first signal output by the local oscillator; and a second mixer of the receiving chain downconverts the received RF signal using the first signal output by the local oscillator. Claim 7 In paragraph 6, the receiving chain is further configured to multiply the first signal output by the local oscillator and the received RF signal to recover the RFID information. Claim 8 In paragraph 6, the local oscillator, the transmitting chain, and the receiving chain are identically located on an integrated circuit, in a device. Claim 9 A device according to claim 1, further comprising a control circuit configured to selectively configure the transmitting chain and the receiving chain to operate in a first operating mode associated with RFID communication or in a second operating mode associated with cellular communication. Claim 10 In claim 9, in the first operation mode associated with RFID communication, the transmitting chain is further configured to generate the CW RF signal; in the second operation mode associated with cellular communication, the transmitting chain is further configured to generate first information signals intended for a network entity of a wireless communication network; in the first operation mode associated with RFID communication, the receiving chain is further configured to demodulate the received RF signal to recover the RFID information; and in the second operation mode associated with cellular communication, another receiving chain is configured to receive second information signals from the network entity. Claim 11 An apparatus according to claim 1, further comprising a control circuit, wherein the control circuit is configured to configure the receiving chain to perform a Clear Channel Assessment (CCA) procedure for an RF channel; and configured to configure the transmitting chain to transmit the CW RF signal in response to the CCA procedure indicating that the RF channel is available for use. Claim 12 A device according to claim 1, wherein the transmitting chain is further configured to generate the CW RF signal for transmission over the ultra-high frequency (UHF) band; and the receiving chain is further configured to monitor the UHF band for the received RF signal. Claim 13 In claim 12, the device comprises at least one of the following: the UHF band is a GSM (global system for mobile communications) band; or a frequency range of 800 megahertz (MHz) to 1 gigahertz (GHz). Claim 14 In claim 1, the device comprises a feedback receiver (FB Rx) including the receiving chain. Claim 15 In paragraph 1, the device is configured as user equipment for cellular communication. Claim 16 A method comprising: generating a continuous wave (CW) radio frequency (RF) signal; coupling the CW RF signal to an antenna through a directional coupler circuit; configuring the directional coupler circuit to couple a received RF signal based on the CW RF signal from the antenna to a receiving chain; and demodulating the received RF signal to recover RF identification (RFID) information from the received RF signal. Claim 17 A method according to claim 16, further comprising the step of generating a control signal for configuring the directional coupler circuit in a reverse mode for an RFID operation mode. Claim 18 A method according to claim 17, further comprising the step of generating a control signal for configuring the directional coupler circuit in a forward mode for a power control measurement operation mode for cellular communication or a voltage standing wave ratio (VSWR) measurement operation mode for cellular communication. Claim 19 A method according to claim 17, further comprising the step of optionally configuring a transmitting chain and a receiving chain to operate in a first operating mode associated with RFID communication or a second operating mode associated with cellular communication. Claim 20 A device comprising: means for generating a continuous wave (CW) radio frequency (RF) signal; directional coupler means for coupling the CW RF signal to an antenna; means for configuring the directional coupler means to couple a received RF signal based on the CW RF signal from the antenna to a receiving means; and means for demodulating the received RF signal to recover RF identification (RFID) information from the received RF signal.

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