Injecting frequency modulated signals into receiver

Abstract

An apparatus for injecting a frequency modulated signal into a receiver is disclosed. In one example aspect, the apparatus includes a receiver, a local oscillator circuit, and an injection circuit. The receiver includes a signal propagation path. The local oscillator circuit is configured to generate a frequency modulated signal. The injection circuit is coupled to the receiver and the local oscillator circuit. The injection circuit is configured to selectively connect the local oscillator circuit to the signal propagation path of the receiver to inject the frequency modulated signal into the signal propagation path of the receiver. The injection circuit is further configured to disconnect the local oscillator circuit from the signal propagation path of the receiver.

Description

Technical Field

[0001] The present disclosure relates generally to wireless transceivers and, more particularly, to measuring the frequency response of a receiver. Background Art

[0002] To increase transmission rates and throughput, cellular and other wireless networks are using signals with higher order modulation, such as 64 or 256 quadrature amplitude modulation (QAM). However, the use of these higher order modulations is limited based on the signal-to-noise ratio that can be achieved in the receiver. If the signal-to-noise ratio is insufficient, the bit error rate at the receiver may become unacceptable. Summary of the invention

[0003] A device for injecting a frequency modulated signal into a receiver is disclosed. In some specific implementations, the frequency modulated signal can be injected at various points within the signal propagation path of the receiver. For example, the frequency modulated signal can be injected at points associated with radio frequency, intermediate frequency and / or baseband frequency. Starting from the injection point, the frequency modulated signal propagates through the receiver and is subject to any distortion that occurs along the signal propagation path. The frequency response of the receiver is measured based on the propagated frequency modulated signal, and the response of the inverse filter is determined to compensate for the distortion. By compensating for the distortion, the signal-to-noise performance of the receiver can be, for example, sufficient to enable higher order modulation to be used for wireless communication while achieving an acceptable bit error rate. Additionally or alternatively, distortion compensation can improve the position and / or movement accuracy associated with proximity detection.

[0004] In one example aspect, a device for injecting a frequency modulated signal into a receiver is disclosed. The device includes a receiver, a local oscillator circuit, and an injection circuit. The receiver includes a signal propagation path. The local oscillator circuit is configured to generate a frequency modulated signal. The injection circuit is coupled to the receiver and the local oscillator circuit. The injection circuit is configured to selectively connect the local oscillator circuit to the signal propagation path of the receiver to inject the frequency modulated signal into the signal propagation path of the receiver. The injection circuit is also configured to disconnect the local oscillator circuit from the signal propagation path of the receiver.

[0005] In one example aspect, an apparatus for injecting a frequency modulated signal into a receiver is disclosed. The apparatus includes components for receiving a wireless communication signal during a wireless communication mode. The components for receiving the wireless communication signal include a signal propagation path. The apparatus also includes components for generating a frequency modulated signal during a calibration mode. The apparatus additionally includes components for injecting the frequency modulated signal into the signal propagation path during the calibration mode.

[0006] In one example aspect, a method for injecting a frequency modulated signal into a receiver is disclosed. The method includes disconnecting a local oscillator circuit from a mixer of the receiver based on a calibration pattern. The method also includes connecting the local oscillator circuit to an input or output of a component disposed within a signal propagation path of the receiver based on the calibration pattern. The method additionally includes generating, by the local oscillator circuit, a frequency modulated signal according to the calibration pattern. The method also includes injecting the frequency modulated signal into the signal propagation path of the receiver.

[0007] In one example aspect, an apparatus for injecting a frequency modulated signal into a receiver is disclosed. The apparatus includes a modem configured to generate a mode control signal. The apparatus also includes a wireless transceiver coupled to the modem and including a portion of a signal propagation path of the receiver. The wireless transceiver is configured to receive the mode control signal. The wireless transceiver is further configured to use a portion of the signal propagation path of the receiver to receive a downlink signal based on the mode control signal indicating a wireless communication mode. The wireless transceiver is further configured to inject the frequency modulated signal into the signal propagation path of the receiver based on the mode control signal indicating a calibration mode. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Figure 1 An example computing device for injecting a frequency modulated signal into a receiver is illustrated.

[0009] Figure 2-1 An example operating environment for a computing device is illustrated.

[0010] Figure 2-2 Another example operating environment for a computing device is illustrated.

[0011] Figure 3 An example sequence flow diagram for operating a computing device is illustrated.

[0012] Figure 4 An example of a wireless transceiver and modem for injecting a frequency modulated signal into a receiver is illustrated.

[0013] Figure 5 An example local oscillator circuit for injecting a frequency modulated signal into a receiver is illustrated.

[0014] Figure 6 Example implementations of a local oscillator circuit and an injection circuit for injecting a frequency modulated signal into a receiver are illustrated.

[0015] Figure 7 An example implementation of a radio frequency integrated circuit for injecting a frequency modulated signal into a receiver is illustrated.

[0016] Figure 8-1 An example configuration of a radio frequency integrated circuit during a calibration mode is illustrated.

[0017] Figure 8-2 An example configuration of a radio frequency integrated circuit during a wireless communication mode is illustrated.

[0018] Figure 8-3 An example configuration of a radio frequency integrated circuit during a proximity detection mode is illustrated.

[0019] Fig. 9 is a flow chart illustrating an example process for injecting a frequency modulated signal into a receiver. DETAILED DESCRIPTION

[0020] To increase transmission rates and throughput, cellular and other wireless networks are using signals with higher order modulation, such as 64 or 256 quadrature amplitude modulation (QAM). However, the use of these higher order modulations is limited based on the signal-to-noise ratio that can be achieved in the receiver. If the signal-to-noise ratio is insufficient, the bit error rate at the receiver may become unacceptable.

[0021] One degradation source that can affect the signal-to-noise ratio of a receiver includes distortion within the passband of a filter within the receiver. Example distortion types may include ripples within the passband or droops at the edges of the passband. In order to improve the signal-to-noise ratio, it is desirable for the receiver to have a nearly distortion-free frequency response. To address this challenge, some techniques measure the total frequency response of the receiver and implement an inverse filter to compensate for the distortion. However, these techniques can be quite complex due to the use of internal noise sources to estimate the total frequency response of the receiver. Sometimes, these noise sources do not appear as white noise. Therefore, the spectrum of the noise is not necessarily flat unless it is averaged over a fairly long time period, which may be on the order of seconds. When estimating the total frequency response of the receiver, the receiver cannot support wireless communication operations, which may be undesirable for this length of time.

[0022] In contrast, this article describes a technique for injecting a frequency modulated signal into a receiver. In some implementations, the frequency modulated signal may be injected at various points within the signal propagation path of the receiver. For example, the frequency modulated signal may be injected at a point associated with a radio frequency, an intermediate frequency, and / or a baseband frequency. From the injection point, the frequency modulated signal propagates through the receiver and is subject to any distortion that occurs along the signal propagation path. The frequency response of the receiver is measured based on the propagated frequency modulated signal, and the response of the inverse filter is determined to compensate for the distortion. By compensating for the distortion, the signal-to-noise performance of the receiver may be, for example, sufficient to enable the use of higher order modulation for wireless communications while achieving an acceptable bit error rate. Additionally or alternatively, distortion compensation may improve the position and / or movement accuracy associated with proximity detection.

[0023] Compared to other techniques that rely on internal noise sources, the frequency modulated signal may have a sufficiently large bandwidth and a substantially flat frequency response to enable the frequency response of the receiver to be measured quickly (e.g., on the order of microseconds). Moreover, the frequency response of the receiver may be easily extracted from time domain samples of the frequency modulated signal. Therefore, determining an appropriate response of the inverse filter to compensate for distortion may be less computationally intensive.

[0024] Figure 1 An example environment 100 for injecting a frequency modulated signal into a receiver is illustrated. In the environment 100, a computing device 102 communicates with a base station 104 via a wireless communication link 106 (wireless link 106). In this example, the computing device 102 is depicted as a smart phone. However, the computing device 102 may be implemented as any suitable computing or electronic device, such as a modem, a cellular base station, customer premises equipment (CPE), a broadband router, an access point, a cellular phone, a gaming device, a navigation device, a media device, a laptop computer, a desktop computer, a tablet computer, a wearable computer, a server, a network attached storage (NAS) device, a smart appliance or other Internet of Things (IoT) device, a medical device, a vehicle-based communication system, a radar, a radio, etc.

[0025] Base station 104 communicates with computing device 102 via wireless link 106, which may be implemented as any suitable type of wireless link. Although depicted as a cellular network tower, base station 104 may represent or be implemented as another device, such as a satellite, a server device, a terrestrial television broadcast tower, an access point, a peer device, a mesh network node, etc. Thus, computing device 102 may communicate with base station 104 or another device via a wireless connection.

[0026] Wireless link 106 may include a downlink of data or control information communicated from base station 104 to computing device 102, an uplink of other data or control information communicated from computing device 102 to base station 104, or both. Wireless link 106 may be implemented using any suitable communication protocol or standard, such as second generation (2G), third generation (3G), fourth generation (4G), or fifth generation (5G) cellular; IEEE 802.11 (e.g., ); IEEE 802.15 (e.g., ); IEEE 802.16 (e.g., ); and so on. In some implementations, wireless link 106 can provide power wirelessly, and base station 104 or computing device 102 can include a power source.

[0027] As shown, computing device 102 includes an application processor 108 and a computer-readable storage medium 110 (CRM 110). Application processor 108 may include any type of processor, such as a multi-core processor, that executes processor executable code stored by CRM 110. CRM 110 may include any suitable type of data storage medium, such as volatile memory (e.g., random access memory (RAM)), non-volatile memory (e.g., flash memory), optical media, magnetic media (e.g., disk), etc. In the context of the present disclosure, CRM 110 is implemented to store instructions 112, data 114, and other information for computing device 102, and therefore does not include transient propagating signals or carrier waves.

[0028] The computing device 102 may also include input / output ports 116 (I / O ports 116) and / or a display 118. The I / O ports 116 enable data exchange or interaction with other devices, networks, or users. The I / O ports 116 may include serial ports (e.g., universal serial bus (USB) ports), parallel ports, audio ports, infrared (IR) ports, user interface ports such as a touch screen, and the like. The display 118 presents graphics of the computing device 102, such as a user interface associated with an operating system, program, or application. Alternatively or additionally, the display 118 may be implemented as a display port or a virtual interface through which the graphical content of the computing device 102 is presented.

[0029] The wireless transceiver 120 of the computing device 102 provides connectivity to a corresponding network and other electronic devices connected thereto. The wireless transceiver 120 may facilitate communications over any suitable type of wireless network, such as a wireless local area network (WLAN), a peer-to-peer (P2P) network, a mesh network, a cellular network, an ultra-wideband (UWB) network, a wireless wide area network (WWAN), and / or a wireless personal area network (WPAN). In the context of the example environment 100, the wireless transceiver 120 enables the computing device 102 to communicate with the base station 104 and the network connected thereto. However, the wireless transceiver 120 may also enable the computing device 102 to communicate "directly" with other devices or networks.

[0030] The wireless transceiver 120 includes circuits and logic for sending and receiving communication signals via the antenna 124. The components of the wireless transceiver 120 may include amplifiers, switches, mixers, analog-to-digital converters, filters, etc. for conditioning communication signals (e.g., for generating or processing signals). The wireless transceiver 120 may also include logic for performing in-phase / quadrature (I / Q) operations such as synthesis, encoding, modulation, decoding, demodulation, etc. In some cases, the components of the wireless transceiver 120 are implemented as separate transmitter and receiver entities. Additionally or alternatively, the wireless transceiver 120 may be implemented using multiple or different parts to implement corresponding transmission and reception operations (e.g., separate transmission chains and reception chains). In general, the wireless transceiver 120 processes data and / or signals associated with data communicated to the computing device 102 via the antenna 124.

[0031] The computing device 102 also includes a modem 122 that is coupled to the wireless transceiver 120. The modem 122, which may include one or more processors, may be implemented within the wireless transceiver 120 or separately from the wireless transceiver 120. Although not explicitly shown, the modem 122 may include a portion of the CRM 110 or may access the CRM 110 to obtain computer-readable instructions. The modem 122 controls the wireless transceiver 120 and enables execution of a variety of different modes. The modem 122 may include baseband circuitry to perform high-rate sampling processes, which may include analog-to-digital conversion, digital-to-analog conversion, Fourier transforms, gain correction, tilt correction, frequency translation, etc. The modem 122 may provide communication data to the wireless transceiver 120 for transmission. The modem 122 may also process baseband signals obtained from the wireless transceiver 120 to generate data, which may be provided to the computing device 102.

[0032] To increase the transmission rate and throughput using higher order modulation, computing device 102 may perform distortion compensation by applying a filter that compensates for at least a portion of the distortion generated by a receiver of computing device 102. During calibration mode 126, computing device 102 injects a frequency modulated signal into a signal propagation path of the receiver to determine an appropriate frequency response of the filter.

[0033] The computing device 102 may also increase the transmission rate and throughput by using signals with higher frequencies and smaller wavelengths. As an example, the computing device 102 may represent a device that supports the fifth generation (5G), which uses frequencies including those at or near the extremely high frequency (EHF) spectrum (e.g., frequencies greater than 24 gigahertz (GHz)) and having wavelengths at or near millimeter wavelengths. These signals have various technical challenges, such as higher path loss than signals used for earlier generations of wireless communications. In some scenarios, 5G wireless signals may have difficulty traveling far enough to make cellular communications feasible at these higher frequencies.

[0034] Transmit power levels can be increased, or transmit beamforming can focus energy in a specific direction to compensate for higher path losses. However, these types of compensation techniques increase power density. The Federal Communications Commission (FCC) has established maximum permissible exposure (MPE) limits to accommodate these higher power densities.

[0035] To meet targeted guidance based on MPE limits, computing device 102 may balance performance with transmit power and other considerations. To achieve this balancing act, some implementations of computing device 102 perform proximity detection in addition to wireless communication. In this case, computing device 102 may operate according to wireless communication mode 128 to perform wireless communication and according to proximity detection mode 130 to perform proximity detection.

[0036] To support the calibration mode 126 and the wireless communication mode 128 (and optionally the proximity detection mode 130), the wireless transceiver 120 includes at least one local oscillator circuit 132 and at least one injection circuit 134. The local oscillator circuit 132 generates a reference signal that supports the active mode. For the calibration mode 126 and / or the proximity detection mode 130, the reference signal can be a frequency modulated signal. For the wireless communication mode 128, the reference signal can be a local oscillator signal.

[0037] The injection circuit 134 enables the frequency modulated signal provided by the local oscillator circuit 132 to be injected into the signal propagation path of the receiver during the calibration mode 126. The injection circuit 134 provides this injection point for the calibration mode 126 without substantially affecting the performance of other modes, such as the wireless communication mode 128 or the proximity detection mode 130. The local oscillator circuit 132 and the injection circuit 134 together at least partially implement various aspects of injecting the frequency modulated signal into the receiver.

[0038] The modem 122 includes a distortion compensation circuit 136. During the calibration mode 126, the distortion compensation circuit 136 measures the frequency response of the receiver based on the injected frequency modulated signal. During the wireless communication mode 128 and / or the proximity detection mode 130, the distortion compensation circuit 136 applies a filter that at least partially compensates for the distortion previously measured during the calibration mode 126. By compensating for such distortion, the distortion compensation circuit 136 enables the computing device 102 to support the use of higher order modulation during the wireless communication mode 128 and / or enables more accurate object detection in the proximity detection mode 130. Figure 2-1 , Figure 2-2 and Figure 3 Aspects of the wireless communication mode 128 and the proximity detection mode 130 are further described.

[0039] Figure 2-1 An example operating environment 200 for a computing device 102 is illustrated. In the example environment 200, a user's hand 202 holds the computing device 102. During the wireless communication mode 128, the computing device 102 communicates with the base station 104 by sending uplink signals 204 (UL signals 204) or receiving downlink signals 206 (DL signals 206) via the antenna 124. However, the user's thumb may represent an object 208 that may be exposed to radiation via the uplink signal 204 and block one or more of the antennas 124.

[0040] In order to detect whether the object 208 is present or within a detectable distance and angle, the computing device 102 operates according to the proximity detection mode 130. During the proximity detection mode 130, the computing device 102 transmits a proximity detection signal 210 via at least one of the antennas 124. The proximity detection signal 210 may be a frequency modulated continuous wave (FMCW) signal or a frequency modulated pulse signal. The frequency modulation type may include linear frequency modulation, triangular frequency modulation, sawtooth frequency modulation, etc. The proximity detection signal 210 propagates through space and is at least partially reflected by the object 208.

[0041] The computing device 102 additionally receives a reflected proximity detection signal 212 via one or more of the antennas 124, which represents a version of the proximity detection signal 210 that is reflected by the object 208. Based on the reflected proximity detection signal 212, the presence of the object 208 can be determined. In some implementations, the computing device 102 also determines the location (e.g., tilt range, orientation, and / or altitude) of the object 208.

[0042] Figure 2-2Another example operating environment 214 for computing device 102 is illustrated. In the depicted configuration, computing device 102 includes antenna arrays 216-1 and 216-2. Through antenna arrays 216-1 and 216-2, computing device 102 can communicate with base station 104 through multiple signal paths 218-1 to 218-3. First signal path 218-1 represents a direct signal path between antenna array 216-1 and base station 104. Second signal path 218-2 represents an indirect signal path between antenna array 216-1, reflector 220, and base station 104. Third signal path 218-3 represents an indirect signal path between antenna array 216-2, reflector 220, and base station 104.

[0043] In the depicted environment, an object 208 (e.g., a finger) blocks the first signal path 218-1. Through proximity detection, the computing device 102 determines that the antenna array 216-1 is blocked. Therefore, the computing device 102 can adjust the transmission parameters of the uplink signal 204 based on the detection. In some specific implementations, the transmission parameters specify different beam steering angles that enable the uplink signal 204 to be transmitted via the antenna array 216-1 using the second signal path 218-2 instead of the first signal path 218-1. The beam steering angle can reduce radiation exposure at the object 208 by directing the main lobe of the uplink signal 204 away from the object 208. Additionally or alternatively, the transmit power of the uplink signal 204 can be reduced for the second signal path 218-2 or the first signal path 218-1.

[0044] In other cases, the transmit parameters may specify a different antenna array 216 for transmitting communication signals. For example, the uplink signal 204 may be transmitted using the third signal path 218-3 using the antenna array 216-2 instead of the antenna array 216-1. By adjusting the transmit parameters, the computing device 102 may maintain communication with the base station 104 while ensuring compliance. Figure 3 An example sequence for switching between the wireless communication mode 128 and the proximity detection mode 130 is further described.

[0045] Figure 3An example sequence flow chart 300 for operating a computing device 102 is illustrated, wherein time passes in a downward direction. An example of a wireless communication mode 128 is shown at 302 and 306, and an example of a proximity detection mode 130 is shown at 304 and 308. The proximity detection mode 130 may occur at fixed time intervals, between active data cycles occurring during wireless communication, at a predetermined time set by the modem 122, during an unused random access channel (RACH) time slot, as part of an initialization process before wireless communication occurs, in response to detection of device movement, based on an indication that a user may be approaching the device (e.g., based on the wireless transceiver 120 observing a power reduction in the downlink signal 206 or the application processor 108 determining that the user is interacting with the display 118 of the computing device 102), or during other times or in response to other events. In some cases, the computing device 102 measures the location of the object 208 during the proximity detection mode 130.

[0046] At 302, computing device 102 transmits a high power (e.g., normal) uplink signal 204-1 that is configured to provide a sufficient distance from a destination, such as the location of base station 104. After transmitting uplink signal 204-1, at 304. computing device 102 transmits proximity detection signal 210-1. As described above, proximity detection signal 210 may enable computing device 102 to detect object 208 and determine whether object 208 is near computing device 102. In this case, proximity detection signal 210-1 is represented by a low power broadband signal. Based on the detection, wireless transceiver 120 may adjust transmission parameters of subsequent uplink signals 204 to take into account MPE compliance guidelines.

[0047] The proximity detection mode 130 may also determine the distance and / or angle relative to the object 208, thereby enabling the transmission of the uplink signal 204 to follow distance-related and / or angle-related guidelines, such as maximum power density. Since power density is proportional to transmit power and inversely proportional to distance, for the same transmit power level, an object 208 at a closer distance is exposed to a higher power density than another object 208 at a farther distance. Therefore, if the object 208 is at a farther distance, a similar power density at the object 208 may be achieved by increasing the transmit power level, and if the object 208 is at a closer distance, a similar power density at the object 208 may be achieved by reducing the transmit power level.

[0048] The power density at the object 208 may also depend on the beam steering angle (e.g., the angle of the main lobe of the radiation pattern). For example, steering the beam steering angle away from an angle relative to the object 208 may reduce the power density at the object 208. By controlling the transmit power and / or the beam steering angle, the computing device 102 may tailor the transmission of the uplink signal 204 so that the power density at the object 208 is below the maximum power density. At the same time, since the distance and / or angle are known, the transmit power level may be increased to a level that facilitates wireless communication and meets compliance guidelines.

[0049] At 306, computing device 102 transmits subsequent uplink signal 204. In the depicted example, if object 208 is not detected, high power uplink signal 204-2 is transmitted. Alternatively, if object 208 is detected, low power uplink signal 204-3 is transmitted. The low transmit power may be, for example, between approximately five decibel milliwatts (dBm) and twenty decibel milliwatts less than the high power signal at 302. In addition or in lieu of changing the power of subsequent uplink signal 204, uplink signal 204-3 may be transmitted using a different antenna array within computing device 102, using a different beam steering angle, using a different frequency, or using a different communication protocol (e.g., relative to the antenna array, beam steering angle, frequency, or communication protocol used to transmit uplink signal 204-1 at 302). Although not shown, the computing device 102 may alternatively skip the wireless communication mode at 306 and perform another proximity detection mode using another antenna array or a different transmit power level to detect objects 208 at various locations or distances around the computing device 102 .

[0050] At 308, the computing device 102 transmits another proximity detection signal 210-2 to attempt to detect the object 208. By scheduling multiple proximity detection signals 210 within a certain time period, the transmission of the uplink signal 204 can be dynamically adjusted based on the changing environment or movement of the object 208. In addition, appropriate adjustments can be made to balance communication performance with compliance or radiation requirements.

[0051] The sequence described above may also be applied to other antennas 124 within the computing device 102. Other antennas 124 may transmit multiple proximity detection signals 210 sequentially or in parallel. Figure 4 Components of computing device 102 that implement wireless communication, proximity detection, and distortion compensation are further described. As noted above, optionally, computing device 102 supports proximity detection mode 130. Thus, while proximity detection is described above, and certain references to proximity detection mode 130 are included below, it should be understood that aspects described herein (e.g., injecting a frequency modulated signal into a receiver) may be performed in the absence of proximity detection or in a device that is not configured to detect proximity.

[0052] Figure 4 An example of a wireless transceiver 120 and a modem 122 for injecting a frequency modulated signal into a receiver is illustrated. The wireless transceiver 120 and the modem 122 together implement a transmitter 402 and a receiver 404. The transmitter 402 and the receiver 404 may be coupled to the same antenna 124 or to different antennas 124.

[0053] In the depicted configuration, the wireless transceiver 120 represents a superheterodyne transceiver that includes a radio frequency integrated circuit 406 (RF IC 406), an intermediate frequency integrated circuit 408 (IF IC 408), and a baseband integrated circuit 410 (baseband IC 410). In other specific implementations (not shown), the wireless transceiver 120 may be implemented as a direct conversion transceiver (or zero IF transceiver) having the radio frequency integrated circuit 406 and the baseband integrated circuit 410 without the intermediate frequency integrated circuit 408. In some examples of implementing a superheterodyne transceiver, the intermediate frequency circuitry and the baseband circuitry are included in a single integrated circuit rather than in separate integrated circuits. Figure 4 In the illustrated individual integrated circuits.

[0054] The RFIC 406 may represent the RF front end of the wireless transceiver 120. Generally speaking, the RFIC 406 includes components designed to operate on analog signals with a radio frequency. The IFIC 408 includes components designed to operate on analog signals with an intermediate frequency. The baseband IC 410 includes components designed to operate at analog and / or digital signals with a baseband frequency. The components of the RFIC 406, the IFIC 408, and the baseband IC 410 may include amplifiers, phase shifters, filters, mixers, and switches. The baseband IC 410 may also include an analog-to-digital converter and a digital-to-analog converter.

[0055] The local oscillator circuit 132 may be integrated into the RF integrated circuit 406, the intermediate frequency integrated circuit 408, or some combination thereof. The injection circuit 134 may be integrated into the RF integrated circuit 406, the intermediate frequency integrated circuit 408, the baseband integrated circuit 410, or some combination thereof. In some implementations, the local oscillator circuit 132 and the injection circuit 134 are implemented in the same integrated circuit (e.g., implemented in the RF integrated circuit 406 or the intermediate frequency integrated circuit). In other implementations, the local oscillator circuit 132 and the injection circuit 134 are implemented across multiple integrated circuits. The distortion compensation circuit 136 is at least partially implemented in the modem 122. Generally speaking, the injection circuit 134 and the distortion compensation circuit 136 are at least partially disposed in the signal propagation path of the receiver 404.

[0056] The receiver 404 may include components, such as filters, that introduce distortion during the wireless communication mode 128 and / or the proximity detection mode 130. A first example filter includes a low pass filter applied after the down-conversion mixer to attenuate harmonic frequencies or intermodulation products. This filter may be implemented in the radio frequency integrated circuit 406, the intermediate frequency integrated circuit 408, or the baseband integrated circuit 410. A second example filter includes an anti-aliasing filter applied before the analog-to-digital converter to reduce aliasing. This filter may be implemented in the baseband integrated circuit 410. A third example filter may include a digital filter, such as a cascaded integrator comb (CIC) filter, which may be implemented by the modem 122.

[0057] During calibration mode 126, local oscillator circuit 132 generates a frequency modulated signal, such as Figure 5 As further described. The injection circuit 134 injects the frequency modulated signal into the receiver 404 at a point along the signal propagation path. For example, the injection circuit 134 may inject the frequency modulated signal into the radio frequency integrated circuit 406, the intermediate frequency integrated circuit 408, or the baseband integrated circuit 410. The receiver 404 propagates the frequency modulated signal to the distortion compensation circuit 136 along the signal propagation path. The distortion compensation circuit 136 measures the distortion within the receiver 404 based on the propagated frequency modulated signal and determines the appropriate frequency response to compensate for the distortion. Due to the time-frequency duality associated with the frequency modulated signal, the distortion compensation circuit 136 can easily measure the frequency response of the receiver 404 based on the time domain samples of the propagated frequency modulated signal.

[0058] During the wireless communication mode 128 and / or the proximity detection mode 130, the modem 122 generates a transmit signal 412, which may include communication data based on the wireless communication mode 128. The modem 122 also provides control information 414 to the RFIC 406. In some implementations, the modem 122 uses frequency division multiplexing to enable both the transmit signal 412 and the control information 414 to be communicated over a single communication path within the wireless transceiver 120. In other implementations, separate communication paths are used to communicate the transmit signal 412 and the control information 414 to the RFIC 406.

[0059] The control information 414 includes at least one transmit parameter and / or at least one receive parameter that configures at least one component within the transmitter 402 or the receiver 404, respectively. As an example, the control information 414 specifies the gain of an amplifier (e.g., a power amplifier, a low noise amplifier, or a variable gain amplifier), phase shift information of an analog phase shifter, an operating state of a switch that connects a selected antenna element of the antenna array 216 to the transmitter 402 or the receiver 404, etc. In some cases, the control information 414 enables the computing device 102 to meet the MPE limit, such as regarding Figure 3 described.

[0060] Depending on the operating mode of the wireless transceiver 120, the transmitter 402 uses the transmit signal 412 to generate the uplink signal 204 or the proximity detection signal 210. For example, the baseband integrated circuit 410 can convert the transmit signal 412 from the digital domain to the analog domain. The intermediate frequency integrated circuit 408 can up-convert the transmit signal 412 from the baseband frequency to the intermediate frequency. The radio frequency integrated circuit 406 can up-convert the transmit signal 412 from the intermediate frequency to the radio frequency, shift the phase of the transmit signal 412, and / or amplify the transmit signal 412 to generate the uplink signal 204 or the proximity detection signal 210. In some specific implementations, the local oscillator circuit 132 generates a local oscillator signal to enable the transmit signal 412 to be up-converted during the wireless communication mode 128. The local oscillator circuit 132 can also generate a frequency modulation signal during the proximity detection mode 130 to up-convert and modulate the transmit signal 412. The radio frequency integrated circuit 406 provides the uplink signal 204 or the proximity detection signal 210 to the antenna 124 for transmission. Antenna 124 may represent an independent antenna or ( Figure 2-2 ) antenna elements of antenna array 216.

[0061] The antenna 124 may also receive the downlink signal 206 during the wireless communication mode 128 or the reflected proximity detection signal 212 during the proximity detection mode 130. Depending on the operating mode of the wireless transceiver 120, the receiver 404 generates a received signal 416 based on the downlink signal 206 or the reflected proximity detection signal 212. For example, the RFIC 406 amplifies the downlink signal 206 or the reflected proximity detection signal 212, shifts the phase of the downlink signal 206 or the reflected proximity detection signal 212, and / or down-converts the downlink signal 206 or the reflected proximity detection signal 212 from a radio frequency to an intermediate frequency (or baseband frequency) to generate the received signal 416. In some implementations, the local oscillator circuit 132 generates a local oscillator signal to enable down-conversion of the downlink signal 206 during the wireless communication mode 128. During the proximity detection mode 130, the RFIC 406 performs a beat frequency operation using the proximity detection signal 210 and the reflected proximity detection signal 212 to generate the received signal 416.

[0062] The intermediate frequency integrated circuit 408 down-converts the received signal 416 from the intermediate frequency to the baseband frequency. The baseband integrated circuit 410 converts the received signal 416 from the analog domain to the digital domain. The modem 122 analyzes the digital version of the received signal 416 to perform other operations associated with the wireless communication mode 128 or the proximity detection mode 130. One of these operations may include applying the filter of the distortion compensation circuit 136 to compensate for the distortion artifacts introduced by the receiver 404.

[0063] The modem 122 also generates a mode control signal 418 that may appropriately configure the local oscillator circuit 132 and / or the injection circuit 134 for an active mode (eg, the calibration mode 126, the wireless communication mode 128, or the proximity detection mode 130). Figure 5 The local oscillator circuit 132 is further described.

[0064] Figure 5 An example local oscillator circuit 132 for injecting a frequency modulated signal into a receiver 404 according to a calibration pattern 126 is illustrated. In the depicted configuration, the local oscillator circuit 132 includes at least one frequency modulated local oscillator 502, at least one local oscillator 504, and at least one selection circuit 506. The frequency modulated local oscillator 502 may be implemented using a voltage ramp generator 508 and a voltage controlled oscillator 510. As an example, the voltage controlled oscillator 510 may be implemented using a wideband open-loop voltage controlled oscillator. By controlling the input voltage to the voltage controlled oscillator 510, the voltage ramp generator 508 may provide a variety of different voltage ramps to enable the voltage controlled oscillator 510 to generate a variety of different frequency modulated signals 512 (e.g., a linear frequency modulated (LFM) signal, a sawtooth frequency modulated signal, a triangular frequency modulated signal, a chirp, etc.).

[0065] During the calibration mode 126, the frequency modulated local oscillator 502 can generate a frequency modulated signal 512 having a first bandwidth. In some implementations, the bandwidth is similar to the wireless communication bandwidth used during the wireless communication mode 128. During the proximity detection mode 130, the frequency modulated local oscillator 502 can generate a frequency modulated signal 512 having a second bandwidth, which can be greater than the first bandwidth. Generally speaking, a larger bandwidth results in better distance resolution for proximity detection.

[0066] The local oscillator 504 may include, for example, a quartz crystal, an inductor-capacitor (LC) oscillator, an oscillator transistor (e.g., a metal oxide semiconductor field effect transistor (MOSFET)), a transmission line, a diode, a piezoelectric oscillator, etc. The configuration of the local oscillator 504 may enable a target phase noise and quality factor to be achieved for the wireless communication mode 128. Generally speaking, the local oscillator 504 generates a local oscillator signal 514 having a stable (e.g., constant) frequency. Although not explicitly shown, the local oscillator circuit 132 may also include a phase-locked loop or an automatic gain control circuit. Any of these components may be coupled to the local oscillator 504 to enable the local oscillator 504 to oscillate at a stable frequency.

[0067] The selection circuit 506 may include a switch or multiplexer controlled by the mode control signal 418. The selection circuit 506 generates a reference signal 516 that is passed to other components within the wireless transceiver 120 and / or the injection circuit 134. The reference signal 516 may be a frequency modulated signal 512 or a local oscillator signal 514 based on the mode control signal 418. If the mode control signal 418 indicates that the calibration mode 126 or the proximity detection mode 130 is active, the selection circuit 506 provides the frequency modulated signal 512 as the reference signal 516. Alternatively, if the mode control signal 418 indicates that the wireless communication mode 128 is active, the selection circuit 506 provides the local oscillator signal 514 as the reference signal 516. The selection circuit 506 enables the wireless transceiver 120 to quickly transition between various modes. About Figure 6 The injection circuit 134 is further described.

[0068] Figure 6 Example implementations of the injection circuit 134 for injecting a frequency modulated signal 512 into the receiver 404 are illustrated. In the depicted configuration, the injection circuit 134 may optionally include at least one buffer 602 and / or at least one frequency translation circuit 604. The buffer 602 may provide isolation and / or amplification. The frequency translation circuit 604 may adjust the frequency of the frequency modulated signal 512. In a first example implementation, the frequency translation circuit 604 may include a frequency multiplier that increases the frequency of the frequency modulated signal 512. For example, the frequency translation circuit 604 may increase the frequency of the frequency modulated signal 512 by approximately 1.5 or 2 times. In a second example implementation, the frequency translation circuit 604 may include a frequency divider that reduces the frequency of the frequency modulated signal 512. For example, the frequency translation circuit 604 may reduce the frequency of the frequency modulated signal 512 by approximately 2 or 4 times.

[0069] In general, the amount by which the frequency translation circuit 604 raises or lowers the frequency of the frequency modulated signal 512 depends on the point within the signal propagation path 608 at which the frequency modulated signal 512 is injected and the target wireless communication band used during the wireless communication mode 128. For example, the frequency translation circuit 604 may raise the frequency of the frequency modulated signal 512 for injection within a point of the signal propagation path 608 associated with a radio frequency. Additionally or alternatively, the frequency translation circuit 604 may lower the frequency of the frequency modulated signal 512 for injection within a point of the signal propagation path 608 associated with an intermediate frequency or baseband frequency. In some cases of generating a frequency modulated signal 512 having a desired frequency, the injection circuit 134 may bypass the frequency translation circuit 604 or be implemented without the frequency translation circuit 604.

[0070] The injection circuit 134 also includes at least one switch 606. The switch 606 is disposed within a signal propagation path 608 of the receiver 404. The switch 606 enables the injection circuit 134 to connect the local oscillator circuit 132 to the signal propagation path 608 of the receiver 404 during the calibration mode 126. In this manner, the injection circuit 134 can inject the frequency modulated signal 512 into the signal propagation path 608. The switch 606 also enables the injection circuit 134 to disconnect the local oscillator circuit 132 from the signal propagation path 608 during the wireless communication mode 128 and the proximity detection mode 130. In this case, the switch 606 enables the receiver 404 to propagate the downlink signal 206, the reflected proximity detection signal 212, or the received signal 416 along the signal propagation path 608. The configuration of the switch 606 is set according to the mode control signal 418, such as with respect to Figure 8-1 to Figure 8-3 Further description. Figure 7 An example implementation of injection circuit 134 within wireless transceiver 120 is further described.

[0071] Figure 7 An example implementation of a radio frequency integrated circuit 406 for injecting a frequency modulated signal 512 into a receiver 404 is illustrated. In the depicted configuration, the radio frequency integrated circuit 406 includes a portion of the transmitter 402, a portion of the receiver 404, the local oscillator circuit 132, and the injection circuit 134. The radio frequency integrated circuit 406 also includes a mixer 702 (e.g., an up-conversion mixer) and an amplifier 704 (e.g., a power amplifier), which are implemented as a portion of the transmitter 402. Additionally, the radio frequency integrated circuit 406 includes an amplifier 706 (e.g., a low noise amplifier) ​​and a mixer 708 (e.g., a down-conversion mixer), which are implemented as a portion of the receiver 404. Both the amplifier 706 and the mixer 708 are disposed within the signal propagation path 608 of the receiver 404.

[0072] During the wireless communication mode 128 or the proximity detection mode 130, the radio frequency integrated circuit 406 can use switches 710-1, 710-2, and 712 to couple the local oscillator circuit 132 to the transmitter 402 and / or the receiver 404. During the calibration mode 126, the radio frequency integrated circuit 406 can use switch 712 and either switch 606-1 or 606-2 to couple the local oscillator circuit 132 to the receiver 404. Switch 710-1 is coupled between the local oscillator circuit 132 and the mixer 702. Switch 712 is coupled to the local oscillator circuit 132, the transmitter 402 (e.g., at the output of the mixer 702), switch 710-2, and the injection circuit 134. Switch 710-2 is coupled to switch 712, the injection circuit 134, the mixer 708, and a continuous wave tone generator 714 of the radio frequency integrated circuit 406. In some implementations, the continuous wave tone generator 714 is implemented as a phase locked loop, which can be part of the local oscillator circuit 132 .

[0073] The injection circuit 134 includes a first buffer 602-1, a first frequency translation circuit 604-1, and a first switch 606-1. The switch 606-1 is coupled to the input of the amplifier 706. Through these components, the injection circuit 134 can inject the frequency modulated signal 512 into a point associated with the radio frequency along the signal propagation path 608. The injection circuit 134 can also optionally or alternatively include a second buffer 602-2, a second frequency translation circuit 714-2, and a second switch 606-2. The second switch 606-2 is coupled to the output of the mixer 708. Through these components, the injection circuit 134 can inject the frequency modulated signal 512 into a point associated with the intermediate frequency in a superheterodyne receiver or the baseband frequency in a direct conversion receiver along the signal propagation path 608. In the superheterodyne receiver, the frequency modulated signal 512 can also or alternatively be injected at the baseband (e.g., after the second down-conversion mixer, not illustrated).

[0074] Using switches 710-1, 710-2, and 712 of RFIC 406 and switches 606-1 and 606-2 of injection circuit 134, wireless transceiver 120 may support Figure 8-1 The calibration mode 126, such as Figure 8-2 The wireless communication mode 128 and / or as described in Figure 8-3 The proximity detection mode 130 . Figure 7The depicted example radio frequency integrated circuit 406 supports calibration mode 126, wireless communication mode 128, and proximity detection mode 130. Other specific implementations of radio frequency integrated circuit 406 may support calibration mode 126 and wireless communication mode 128, and may not support proximity detection mode 130. In this case, radio frequency integrated circuit 406 may not include switch 712. Therefore, switch 710-2 and injection circuit 134 are coupled to switch 710-1 and local oscillator circuit 132.

[0075] Figure 8-1 An example configuration of the radio frequency integrated circuit 406 during the calibration mode 126 is illustrated. In the depicted configuration, the local oscillator circuit 132 generates the frequency modulated signal 512 as the reference signal 516. The switch 710-1 is in an open state that disconnects the local oscillator circuit 132 from the mixer 702. The switch 712 is in a first state that connects the local oscillator circuit 132 to the injection circuit 134. The switch 710-2 is in a first state that connects the continuous wave tone generator 714 to the mixer 708.

[0076] At different times, the injection circuit 134 can connect the local oscillator circuit 132 to different points along the signal propagation path 608. For example, at a first time interval during the calibration mode 126, the switch 606-1 is in a first state that connects the local oscillator circuit 132 to the input of the amplifier 706. Moreover, the switch 606-2 is in a second state that disconnects the local oscillator circuit 132 from the output of the mixer 708 and connects the output of the mixer 708 to another component (not shown) within the signal propagation path 608. The first state of the switch 606-1 and the second state of the switch 606-2 are represented by solid lines to indicate that these states occur during the same time interval. The states of the switches 606-1, 606-2, and 712 enable the frequency modulated signal 512 to be injected at the input of the amplifier 706 and propagated to the modem 122.

[0077] At a second time interval during the calibration mode 126, the switch 606-1 is in a second state that disconnects the local oscillator circuit 132 from the amplifier 706. Also, the switch 606-2 is in a first state that connects the local oscillator circuit 132 to the output of the mixer 708. The second state of the switch 606-1 and the first state of the switch 606-2 are represented by dashed lines to indicate that these states occur during the same time interval. The states of the switches 606-1, 606-2, and 712 enable the frequency modulated signal 512 to be injected at the output of the mixer 708 and propagated to the modem 122.

[0078] Figure 8-2An example configuration of the radio frequency integrated circuit 406 during the wireless communication mode 128 is illustrated. In the depicted configuration, the local oscillator circuit 132 generates the local oscillator signal 514 as the reference signal 516. During transmission, the switch 710-1 is in a closed state connecting the local oscillator circuit 132 to the mixer 702. This enables the transmitter 402 to generate the uplink signal 204 by up-converting the transmit signal 412 to a radio frequency using the local oscillator signal 514.

[0079] During reception, switch 712 is in a first state that connects local oscillator circuit 132 to switch 710-2. Switch 710-2 is in a second state that connects switch 712 to mixer 708. This enables receiver 404 to generate receive signal 416 by down-converting downlink signal 206 to an intermediate frequency using local oscillator signal 514. Switches 606-1 and 606-2 are in a second state that enables downlink signal 206 and receive signal 416 to propagate along signal propagation path 608 to modem 122.

[0080] Figure 8-3 An example configuration of the radio frequency integrated circuit 406 during the proximity detection mode 130 is illustrated. In the depicted configuration, the local oscillator circuit 132 generates the frequency modulated signal 512 as the reference signal 516. The switch 710-1 is in a closed state connecting the local oscillator circuit 132 to the mixer 702. This enables the transmitter 402 to generate the proximity detection signal 210 by up-converting the transmit signal 412 to a radio frequency and modulating the transmit signal 412 using the frequency modulated signal 512.

[0081] The switch 712 is in a second state connecting the transmitter 402 to the switch 710-2. The switch 710-2 is in a second state connecting the switch 712 to the mixer 708. This enables the receiver 404 to generate the received signal 416 by down-converting and demodulating the reflected proximity detection signal 212 using the proximity detection signal 210. The switches 606-1 and 606-2 are in a second state enabling the reflected proximity detection signal 212 and the received signal 416 to propagate along the signal propagation path 608 to the modem 122.

[0082] Although examples of local oscillator circuit 132 and injection circuit 134 are shown as Figure 7 to Figure 8-3 4, but other implementations of the wireless transceiver 120 may include the local oscillator circuit 132 and / or the injection circuit 134 implemented in the intermediate frequency integrated circuit 408 and / or the baseband integrated circuit 410. In these implementations, the frequency modulated signal 512 may be injected at other points along the signal propagation path 608, including points associated with the intermediate frequency and / or the baseband frequency.

[0083] Fig. 9 9 is a flow chart illustrating an example process 900 for injecting a frequency modulated signal into a receiver. The process 900 is described in terms of a set of blocks 902 to 910 that specify operations that may be performed. However, the operations are not necessarily limited to Fig. 9 The order shown or described herein is not intended to be construed as such, as the operations may be performed in an alternative order or in a completely or partially overlapping manner. Moreover, more, fewer, and / or different operations may be performed to perform process 900 or an alternative process. Figure 1 or Figure 4 The wireless transceiver 120 and the modem 122 of the process 900 perform the operations represented by the illustrated blocks. More specifically, the process 900 may be performed at least in part by: Figure 5 The local oscillator circuit 132 shown and Figure 6 The injection circuit 134 is shown performing the operations of process 900 .

[0084] At 902, the local oscillator circuit is disconnected from the mixer of the receiver based on the calibration mode. For example, the switch 710-2 disconnects the local oscillator circuit 132 from the mixer 708 of the receiver 404 based on the mode control signal 418 indicating that the calibration mode 126 is active. The switch 710-1 can also disconnect the local oscillator circuit 132 from the mixer 702 of the transmitter 402.

[0085] At 904, the local oscillator circuit is connected to an input or output of a component disposed within a signal propagation path of the receiver based on the calibration mode. For example, switch 712 and switch 606-1 or 606-2 connect the local oscillator circuit 132 to an input or output of a component disposed within a signal propagation path 608 of the receiver 404. Figure 8-1 In the example shown, the local oscillator circuit 132 may be connected to an input of the amplifier 706 or an output of the mixer 708 .

[0086] At 906, a frequency modulated signal is generated by the local oscillator circuit according to the calibration pattern. For example, the local oscillator circuit 132 generates the frequency modulated signal 512 according to the calibration pattern 126, such as Figure 5 In some examples, the frequency modulation signal 512 represents a linear frequency modulation signal.

[0087] At 908, a frequency modulated signal is injected into the signal propagation path of the receiver. Figure 8-1 As shown, the injection circuit 134 injects the frequency modulated signal 512 into the signal propagation path of the receiver 404 .

[0088] Some aspects are described below.

[0089] Aspect 1: A device comprising:

[0090] a receiver, the receiver comprising a signal propagation path;

[0091] a local oscillator circuit configured to generate a frequency modulated signal; and

[0092] an injection circuit coupled to the receiver and the local oscillator circuit, the injection circuit being configured to selectively:

[0093] Connecting the local oscillator circuit to the signal propagation path of the receiver to inject the frequency modulated signal into the signal propagation path of the receiver

[0094] in; and

[0095] The local oscillator circuit is disconnected from the signal propagation path of the receiver.

[0096] Aspect 2: The apparatus according to aspect 1, further comprising:

[0097] A radio frequency integrated circuit includes the local oscillator circuit, the injection circuit, and at least a portion of the signal propagation path of the receiver.

[0098] Aspect 3: The device according to aspect 2, wherein:

[0099] The radio frequency integrated circuit includes an amplifier; and

[0100] The injection circuit is configured to selectively:

[0101] connecting the local oscillator circuit to an input of the amplifier to inject the frequency modulated signal into the signal propagation path of the receiver; and

[0102] The local oscillator circuit is disconnected from the input of the amplifier.

[0103] Aspect 4: The device according to aspect 2 or 3, wherein:

[0104] The radio frequency integrated circuit includes a mixer; and

[0105] The injection circuit is configured to selectively:

[0106] connecting the local oscillator circuit to the output of the mixer to inject the frequency modulated signal into the signal propagation path of the receiver; and

[0107] The local oscillator circuit is disconnected from the output of the mixer.

[0108] Aspect 5: The device according to any one of aspects 2 to 4, wherein:

[0109] The radio frequency integrated circuit comprises a first component and a second component; and

[0110] The injection circuit is configured to selectively:

[0111] connecting the local oscillator circuit to the first component to inject the frequency modulated signal into the signal propagation path of the receiver;

[0112] connecting the local oscillator circuit to the second component to inject the frequency modulated signal into the signal propagation path of the receiver; and

[0113] The local oscillator circuit is disconnected from the first component and the second component.

[0114] Aspect 6: The apparatus according to any preceding aspect, wherein the injection circuit comprises:

[0115] at least one frequency translation circuit coupled to the local oscillator circuit, the at least one frequency translation circuit configured to increase or decrease the frequency of the frequency modulated signal; and

[0116] at least one switch coupled to the at least one frequency conversion circuit and disposed within the signal propagation path, the at least one switch being configured to select

[0117] Sexually:

[0118] connecting the at least one frequency translation circuit to components within the signal propagation path of the receiver; and

[0119] The at least one frequency translation circuit is disconnected from the component and connected to another component within the signal propagation path of the receiver.

[0120] Aspect 7: The apparatus of aspect 6, wherein the injection circuit comprises at least one buffer coupled between the local oscillator circuit and the at least one frequency translation circuit.

[0121] Aspect 8: The apparatus according to any preceding aspect, wherein the receiver is configured to propagate the frequency modulated signal along the signal propagation path according to a calibration pattern.

[0122] Aspect 9: The apparatus according to aspect 8, wherein:

[0123] The receiver includes a distortion compensation circuit, wherein the distortion compensation circuit is arranged on the signal

[0124] In the signal propagation path, the distortion compensation circuit is configured as follows:

[0125] receiving a transmitted frequency modulated signal;

[0126] determining a frequency response of the receiver based on the propagated frequency modulated signal; and

[0127] A filter is applied having a frequency response that at least partially compensates for distortion artifacts present in the frequency response of the receiver.

[0128] Aspect 10: The apparatus according to aspect 9, wherein:

[0129] The receiver includes at least one filter disposed within the signal propagation path and coupled between the injection circuit and the distortion compensation circuit;

[0130] The at least one filter has a frequency response having ripple in a passband or droop at an edge of the passband; and

[0131] The distortion artifacts are associated with the ripples in the passband or the droop at the edges of the passband.

[0132] Aspect 11: The apparatus according to any preceding aspect, wherein the frequency modulated signal comprises a linear frequency modulated signal.

[0133] Aspect 12: The apparatus according to any of the preceding aspects, wherein:

[0134] The local oscillator circuit is configured to selectively:

[0135] generating the frequency modulated signal based on a calibration pattern; and

[0136] generating a local oscillator signal based on a wireless communication mode; and

[0137] The receiver is configured to:

[0138] receiving a downlink signal based on the wireless communication mode; and

[0139] The frequency of the downlink signal is downconverted using the local oscillator signal.

[0140] Aspect 13: The apparatus according to aspect 12, wherein the local oscillator circuit comprises:

[0141] a voltage ramp generator and a voltage controlled oscillator, the voltage ramp generator and the voltage controlled oscillator jointly configured to generate the frequency modulated signal;

[0142] a local oscillator configured to generate the local oscillator signal;

[0143] and

[0144] A selection circuit is configured to:

[0145] providing the frequency modulated signal to the injection circuit based on the calibration pattern; and

[0146] The local oscillator signal is provided to the receiver based on the wireless communication mode.

[0147] Aspect 14: The apparatus according to any of the preceding aspects, further comprising:

[0148] a transmitter coupled to the local oscillator circuit, wherein:

[0149] The frequency modulation signal comprises a first frequency modulation signal;

[0150] The local oscillator circuit is configured to selectively:

[0151] generating the first frequency modulated signal based on a calibration pattern; and

[0152] generating a second frequency modulated signal based on the proximity detection mode; and

[0153] The transmitter is configured to generate a proximity detection signal by performing frequency up-conversion using the second frequency modulation signal based on the proximity detection mode.

[0154] Aspect 15: The apparatus according to aspect 14, wherein:

[0155] The first frequency modulated signal has a first bandwidth; and

[0156] The second frequency modulated signal has a second bandwidth greater than the first bandwidth.

[0157] Aspect 16: A device comprising:

[0158] means for receiving wireless communication signals during a wireless communication mode, said means for receiving comprising a signal propagation path;

[0159] means for generating a frequency modulated signal during a calibration mode; and

[0160] Means for injecting said frequency modulated signal into said signal propagation path during said calibration mode.

[0161] Aspect 17: The apparatus according to Aspect 16, wherein the means for injecting the frequency modulated signal includes means for adjusting the frequency of the frequency modulated signal.

[0162] Aspect 18: The apparatus according to Aspect 17, wherein the means for adjusting the frequency of the frequency modulated signal comprises means for increasing the frequency of the frequency modulated signal.

[0163] Aspect 19: The apparatus according to aspect 17 or 18, wherein the means for adjusting the frequency of the frequency modulated signal comprises means for reducing the frequency of the frequency modulated signal.

[0164] Aspect 20: A method comprising:

[0165] disconnecting a local oscillator circuit from a mixer of the receiver based on a calibration mode;

[0166] connecting the local oscillator circuit to an input or output of a component disposed within a signal propagation path of the receiver based on the calibration pattern;

[0167] generating, by the local oscillator circuit, a frequency modulated signal according to the calibration pattern; and

[0168] The frequency modulated signal is injected into the signal propagation path of the receiver.

[0169] Aspect 21: The method according to Aspect 20, wherein the frequency modulated signal exhibits a linear characteristic between the frequency and time of the frequency modulated signal.

[0170] Aspect 22: The method according to aspect 20 or 21, further comprising:

[0171] disconnecting the local oscillator circuit from the input or the output of the component based on a proximity detection mode;

[0172] connecting the local oscillator circuit to a mixer of a transmitter based on the proximity detection mode;

[0173] Another frequency modulation is generated by the local oscillator circuit according to the proximity detection mode.

[0174] control signals; and

[0175] A proximity detection signal is generated by up-converting a transmission signal using the other frequency modulation signal and the mixer of the transmitter.

[0176] Aspect 23: The method according to Aspect 22 further includes:

[0177] connecting an output of the mixer of the transmitter to a mixer of the receiver based on the proximity detection mode; and

[0178] The input or the output of the component is connected to another component disposed within the signal propagation path of the receiver based on the proximity detection mode.

[0179] Aspect 24: The method according to any one of aspects 20 to 23, further comprising:

[0180] disconnecting the local oscillator circuit from the input or the output of the component based on a wireless communication mode;

[0181] connecting the input or the output of the component to another component disposed within the signal propagation path of the receiver based on the wireless communication mode;

[0182] connecting the local oscillator circuit to a mixer of the receiver based on the wireless communication mode; and

[0183] A local oscillation signal is generated by the local oscillator circuit according to the wireless communication mode.

[0184] Aspect 25: A device comprising:

[0185] a modem configured to generate a mode control signal; and

[0186] A wireless transceiver coupled to the modem and comprising a receiving

[0187] The wireless transceiver is configured to:

[0188] receiving the mode control signal;

[0189] indicating a wireless communication mode using the portion of the signal propagation path of the receiver to receive downlink signals based on the mode control signal; and

[0190] A frequency modulated signal is injected into the signal propagation path of the receiver based on the mode control signal indicating a calibration mode.

[0191] Aspect 26: The apparatus of aspect 25, wherein the wireless transceiver is configured to inject the frequency modulated signal at a point within the signal propagation path associated with a radio frequency.

[0192] Aspect 27: The apparatus of aspect 25 or 26, wherein the wireless transceiver is configured to inject the frequency modulated signal at a point within the signal propagation path associated with an intermediate frequency.

[0193] Aspect 28: The apparatus of any one of aspects 25 to 27, wherein the wireless transceiver is configured to inject the frequency modulated signal at a point within the signal propagation path associated with a baseband frequency.

[0194] Aspect 29: The apparatus according to any one of aspects 25 to 28, wherein the frequency modulated signal comprises a linear frequency modulated signal.

[0195] Aspect 30: The apparatus according to any one of aspects 25 to 29, wherein:

[0196] The wireless transceiver is configured to propagate the frequency modulated signal through the portion of the signal propagation path of the receiver based on the calibration pattern; and

[0197] The modem comprises:

[0198] another portion of the signal propagation path of the receiver; and

[0199] a distortion compensation circuit, the distortion compensation circuit being arranged in the other part of the signal propagation path, the distortion compensation circuit being configured to:

[0200] receiving a transmitted frequency modulated signal;

[0201] determining a frequency response of the receiver based on the propagated frequency modulated signal; and

[0202] The downlink signal is filtered using a filter having a frequency response that at least partially compensates for distortion artifacts present in the frequency response of the receiver.

[0203] Unless the context dictates otherwise, the use of the word "or" herein may be considered an "inclusive or" or use of a term that permits inclusion or application of one or more items linked by the word "or" (e.g., the phrase "A or B" may be interpreted as permitting only "A," only "B," or both "A" and "B"). As used herein, a phrase referring to "at least one of" a list of items refers to any combination of those items (including a single member). As an example, "at least one of a, b, or c" is intended to encompass: a, b, c, ab, ac, bc, and abc, as well as any combination with multiple identical elements (e.g., aa, aaa, aab, aac, abb, acc, bb, bbb, bbc, cc, and ccc, or any other ordering of a, b, and c). In addition, the items represented in the drawings and the terms discussed herein may indicate one or more items or terms, and thus the singular or plural forms of those items and terms may be referred to interchangeably in this written description. Finally, although the subject matter has been described in language specific to structural features or methodological operations, it is to be understood that the subject matter defined in the appended claims is not necessarily limited to the specific features or operations described above, including not necessarily being limited to the organization in which the features are arranged or the order in which the operations are performed.

Claims

1. A device, comprising: a receiver, the receiver comprising a signal propagation path; a local oscillator circuit configured to generate a frequency modulated signal; and an injection circuit coupled to the receiver and the local oscillator circuit, the injection circuit being configured to selectively: connecting the local oscillator circuit to the signal propagation path of the receiver to inject the frequency modulated signal into the signal propagation path of the receiver; and The local oscillator circuit is disconnected from the signal propagation path of the receiver.

2. The apparatus according to claim 1, further comprising: A radio frequency integrated circuit includes the local oscillator circuit, the injection circuit, and at least a portion of the signal propagation path of the receiver.

3. The device according to claim 2, wherein: The radio frequency integrated circuit includes an amplifier; and The injection circuit is configured to selectively: connecting the local oscillator circuit to an input of the amplifier to inject the frequency modulated signal into the signal propagation path of the receiver; and The local oscillator circuit is disconnected from the input of the amplifier.

4. The device according to claim 2, wherein: The radio frequency integrated circuit includes a mixer; and The injection circuit is configured to selectively: connecting the local oscillator circuit to the output of the mixer to inject the frequency modulated signal into the signal propagation path of the receiver; and The local oscillator circuit is disconnected from the output of the mixer.

5. The device according to claim 2, wherein: The radio frequency integrated circuit comprises a first component and a second component; and The injection circuit is configured to selectively: connecting the local oscillator circuit to the first component to inject the frequency modulated signal into the signal propagation path of the receiver; connecting the local oscillator circuit to the second component to inject the frequency modulated signal into the signal propagation path of the receiver; and The local oscillator circuit is disconnected from the first component and the second component.

6. The apparatus of claim 1, wherein the injection circuit comprises: at least one frequency translation circuit coupled to the local oscillator circuit, the at least one frequency translation circuit configured to increase or decrease the frequency of the frequency modulated signal; and at least one switch coupled to the at least one frequency translation circuit and disposed within the signal propagation path, the at least one switch being configured to selectively: connecting the at least one frequency translation circuit to components within the signal propagation path of the receiver; as well as The at least one frequency translation circuit is disconnected from the component and connected to another component within the signal propagation path of the receiver.

7. The apparatus of claim 6, wherein the injection circuit comprises at least one buffer coupled between the local oscillator circuit and the at least one frequency translation circuit.

8. The apparatus of claim 1, wherein the receiver is configured to propagate the frequency modulated signal along the signal propagation path according to a calibration pattern.

9. The device according to claim 8, wherein: The receiver includes a distortion compensation circuit, which is arranged in the signal propagation path, and the distortion compensation circuit is configured to: receiving a transmitted frequency modulated signal; determining a frequency response of the receiver based on the propagated frequency modulated signal; and A filter is applied having a frequency response that at least partially compensates for distortion artifacts present in the frequency response of the receiver.

10. The device according to claim 9, wherein: The receiver includes at least one filter disposed within the signal propagation path and coupled between the injection circuit and the distortion compensation circuit; The at least one filter has a frequency response having ripple in a passband or droop at an edge of the passband; and The distortion artifacts are associated with the ripples in the passband or the droop at the edges of the passband.

11. The apparatus of claim 1, wherein the frequency modulated signal comprises a linear frequency modulated signal.

12. The device according to claim 1, wherein: The local oscillator circuit is configured to selectively: generating the frequency modulated signal based on a calibration pattern; and generating a local oscillator signal based on a wireless communication mode; and The receiver is configured to: receiving a downlink signal based on the wireless communication mode; as well as The frequency of the downlink signal is downconverted using the local oscillator signal.

13. The apparatus of claim 12, wherein the local oscillator circuit comprises: a voltage ramp generator and a voltage controlled oscillator, the voltage ramp generator and the voltage controlled oscillator jointly configured to generate the frequency modulated signal; a local oscillator configured to generate the local oscillator signal; and A selection circuit is configured to: providing the frequency modulated signal to the injection circuit based on the calibration pattern; as well as The local oscillator signal is provided to the receiver based on the wireless communication mode.

14. The apparatus according to claim 1, further comprising: a transmitter coupled to the local oscillator circuit, wherein: The frequency modulation signal comprises a first frequency modulation signal; The local oscillator circuit is configured to selectively: generating the first frequency modulated signal based on a calibration pattern; and generating a second frequency modulated signal based on the proximity detection mode; and The transmitter is configured to generate a proximity detection signal by performing frequency up-conversion using the second frequency modulation signal based on the proximity detection mode.

15. The device according to claim 14, wherein: The first frequency modulated signal has a first bandwidth; and The second frequency modulated signal has a second bandwidth greater than the first bandwidth.

16. A device, comprising: means for receiving wireless communication signals during a wireless communication mode, said means for receiving comprising a signal propagation path; means for generating a frequency modulated signal during a calibration mode; and Means for injecting said frequency modulated signal into said signal propagation path during said calibration mode.

17. The apparatus of claim 16, wherein the means for injecting the frequency modulated signal comprises means for adjusting the frequency of the frequency modulated signal.

18. The apparatus of claim 17, wherein the means for adjusting the frequency of the frequency modulated signal comprises means for increasing the frequency of the frequency modulated signal.

19. The apparatus of claim 17, wherein the means for adjusting the frequency of the frequency modulated signal comprises means for decreasing the frequency of the frequency modulated signal.

20. A method comprising: disconnecting a local oscillator circuit from a mixer of the receiver based on a calibration mode; connecting the local oscillator circuit to an input or output of a component disposed within a signal propagation path of the receiver based on the calibration pattern; generating a frequency modulated signal by the local oscillator circuit according to the calibration pattern; as well as The frequency modulated signal is injected into the signal propagation path of the receiver.

21. The method of claim 20, wherein the frequency modulated signal exhibits a linear characteristic between frequency and time of the frequency modulated signal.

22. The method according to claim 20, further comprising: disconnecting the local oscillator circuit from the input or the output of the component based on a proximity detection mode; connecting the local oscillator circuit to a mixer of a transmitter based on the proximity detection mode; generating, by the local oscillator circuit, another frequency modulated signal according to the proximity detection mode; as well as A proximity detection signal is generated by up-converting a transmission signal using the other frequency modulation signal and the mixer of the transmitter.

23. The method according to claim 22, further comprising: connecting an output of the mixer of the transmitter to a mixer of the receiver based on the proximity detection mode; as well as The input or the output of the component is connected to another component disposed within the signal propagation path of the receiver based on the proximity detection mode.

24. The method of claim 20, further comprising: disconnecting the local oscillator circuit from the input or the output of the component based on a wireless communication mode; connecting the input or the output of the component to another component disposed within the signal propagation path of the receiver based on the wireless communication mode; connecting the local oscillator circuit to a mixer of the receiver based on the wireless communication mode; as well as A local oscillation signal is generated by the local oscillator circuit according to the wireless communication mode.

25. An apparatus, comprising: a modem configured to generate a mode control signal; and a wireless transceiver coupled to the modem and comprising a portion of a signal propagation path of a receiver, the wireless transceiver being configured to: receiving the mode control signal; indicating a wireless communication mode using the portion of the signal propagation path of the receiver to receive downlink signals based on the mode control signal; as well as A frequency modulated signal is injected into the signal propagation path of the receiver based on the mode control signal indicating a calibration mode.

26. The apparatus of claim 25, wherein the wireless transceiver is configured to inject the frequency modulated signal at a point within the signal propagation path associated with a radio frequency.

27. The apparatus of claim 25, wherein the wireless transceiver is configured to inject the frequency modulated signal at a point within the signal propagation path associated with an intermediate frequency.

28. The apparatus of claim 25, wherein the wireless transceiver is configured to inject the frequency modulated signal at a point within the signal propagation path associated with a baseband frequency.

29. The apparatus of claim 25, wherein the frequency modulated signal comprises a linear frequency modulated signal.

30. The apparatus of claim 25, wherein: The wireless transceiver is configured to propagate the frequency modulated signal through the portion of the signal propagation path of the receiver based on the calibration pattern; and The modem comprises: another portion of the signal propagation path of the receiver; and a distortion compensation circuit, the distortion compensation circuit being arranged in the other part of the signal propagation path, the distortion compensation circuit being configured to: receiving a transmitted frequency modulated signal; determining a frequency response of the receiver based on the propagated frequency modulated signal; and The downlink signal is filtered using a filter having a frequency response that at least partially compensates for distortion artifacts present in the frequency response of the receiver.

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