Abstract: A device includes a transmitter coupled to an antenna, a receiver coupled to the at least one antenna, and a processing device to: cause the transmitter to radiate a radio frequency (RF) signal; receive, via the receiver, a reflective RF signal based on the radiated RF signal; detect, within a data array of the reflective RF signal, a maximum peak among a plurality of signal peaks, the maximum peak being indicative of a first distance to a first object relative to the at least one antenna; and cancel, using cascading peak cancellation on the spectrum, the maximum peak while detecting a first next-highest peak of the plurality of signal peaks compared to the maximum peak, the first next-highest peak being indicative of a second distance to a second object.

Abstract: Techniques are described for using one or more wireless host devices to perform tire localization of TPMS sensor data by determining received signal strength indicator (RSSI) signatures that are unique to the wireless communication channel between a host device and each TPMS sensor. RSSI signatures represents a periodic variation of the wireless communication channel between a host device on the car body and a TPMS sensor in a rotating tire. Characteristics of the communication channel is a function of the wheel angle and is periodic with wheel rotations. The RSSI signatures may be created by matching RSSI measurements of packets received by the host device from a TPMS sensor with wheel angles derived from wheel speed sensor (WSS) data of the anti-lock braking system (ABS). The RSSI signatures are a unique marker of each wheel that may be used to identify the locations of the TPMS sensors for tire localization.

Abstract: An example method for estimating the angle-of-arrival (AoA) and other parameters of radio frequency (RF) signals that are received by an antenna array comprises: receiving a plurality of radio frequency (RF) signal power measurements by a plurality of antenna elements at a plurality of RF channels; computing, by applying a machine learning model to the plurality of RF signal power measurements, an estimated RF signal parameter value; and outputting the RF signal parameter value.

Abstract: A system and method reconfiguring an antenna for reducing and/or eliminating the effects of multipath on a phase-based measurement system. The method includes steering an antenna unit into a first direction to cause the antenna unit to generate a first constant tone (CT) signal based on a plurality of multipath signals. The method includes performing a phase measurement on the first CT signal to generate a first phase measurement value. The method includes steering the antenna unit into a second direction to cause the antenna unit to generate a second CT signal based on the plurality of multipath signals. The method includes performing a phase measurement on the second CT signal to generate a second phase measurement value. The method includes determining a change in multipath interference at the antenna unit among the plurality of multipath signals. The method includes re-steering the antenna unit into the first direction.

Abstract: Systems, methods, and devices detect radio frequency identification devices. Methods include transmitting a signal from a transmitter of a wireless device compatible with a wireless communications protocol, receiving, using a receiver of the wireless device, an encoded signal from a radio frequency identification (RFID) device, and determining a plurality of data values based, at least in part, on the received encoded signal. Methods further include generating an estimated distance value based, at least in part, on the received encoded signal, the estimated distance value representing an estimate of a distance between the wireless device and the RFID device.

Abstract: Implementations disclosed describe devices for improving wireless localization and ranging operations. In an example embodiment, a circuit includes a receive chain configured to receive a first signal of a first frequency in a first frequency band. The circuit includes a transmit chain configured to transmit a second signal of a second frequency in a second frequency band. The circuit includes an active reflection circuit coupled between the receive and transmit chains. The active reflection circuit includes a frequency conversion scheme. The frequency conversion scheme is configured to receive an input signal from the RX chain at the first frequency, convert the input signal to an output signal at the second frequency, and provide the output signal to the TX chain.

Abstract: A multi-protocol network and methods for operating the same are provided. The method begins with establishing a wireless-connection between a first transceiver in a first device and a second-transceiver in a second device using a wireless-protocol. First, wired-protocol packets and non-packet data are received and converted in the first device to second-packets compatible with the wireless-protocol by inserting synchronization-bits non-packet data in a preamble field. This is initiated by sensing arrival of the preamble without waiting for a start of data. The second-packets are transmitted from the first transceiver to the second, and converted to third-packets compatible with the wired-protocol by removing the synchronization-bits. Latency is improved by initiating/starting a packet to the wired controller before a data portion of the packet is received. The number of synchronization bits is selected so the second-packets are aligned and synchronized with wireless-protocol packets.

Abstract: Techniques are described for using one or more wireless host devices to perform tire localization of TPMS sensor data by determining received signal strength indicator (RSSI) signatures that are unique to the wireless communication channel between a host device and each TPMS sensor. RSSI signatures represents a periodic variation of the wireless communication channel between a host device on the car body and a TPMS sensor in a rotating tire. Characteristics of the communication channel is a function of the wheel angle and is periodic with wheel rotations. The RSSI signatures may be created by matching RSSI measurements of packets received by the host device from a TPMS sensor with wheel angles derived from wheel speed sensor (WSS) data of the anti-lock braking system (ABS). The RSSI signatures are a unique marker of each wheel that may be used to identify the locations of the TPMS sensors for tire localization.

Abstract: Techniques described here introduce signature frequency modulation to unmodulated pulse signals as frequency chirps to enhance the security of multi-carrier phase-based ranging signals. The characteristics of the chirps may be mutually known by an initiator and a desired reflector of the ranging applications. The characteristics of the chirps may vary between the multi-carrier signals to thwart any attempt by an eavesdropper to predict the chirps. In one aspect, the characteristics of the chirps may be calculated for each timeslot of a ranging cycle by two authorized devices using a ciphering algorithm such as the Advanced Encryption Standard (AES) based on a shared security key. Each call of the AES may generate one or more pseudo-random numbers based on the shared security key and a time-varying initialization vector that increments every timeslot. Fields of the pseudo-random number may be extracted to determine the characteristics of the chirps associated with the timeslot.

Abstract: A system and method reconfiguring an antenna for reducing and/or eliminating the effects of multipath on a phase-based measurement system. The method includes steering an antenna unit into a first direction to cause the antenna unit to generate a first constant tone (CT) signal based on a plurality of multipath signals. The method includes performing a phase measurement on the first CT signal to generate a first phase measurement value. The method includes steering the antenna unit into a second direction to cause the antenna unit to generate a second CT signal based on the plurality of multipath signals. The method includes performing a phase measurement on the second CT signal to generate a second phase measurement value. The method includes determining a change in multipath interference at the antenna unit among the plurality of multipath signals. The method includes re-steering the antenna unit into the first direction.

Abstract: Implementations disclosed describe techniques and systems for efficient determination and tracking of trajectories of objects in an environment of a wireless device. The disclosed techniques include, among other things, obtaining multiple sets of sensing values that characterize one or more radio signals received, during a respective sensing event, from an object in an environment of the wireless device. The sensing signals may be carried by waves with randomly selected frequencies representing a portion of all frequencies that are used as working sensing frequencies. Multiple techniques of efficient frequency interpolation and temporal interpolation are disclosed that reconstruct the sensing values to the full range of working frequencies. The reconstructed sensing values may then be used to track objects in the environment.

Abstract: Implementations disclosed describe techniques and systems for efficient determination and tracking of trajectories of objects in an environment of a wireless device. The disclosed techniques include, among other things, determining multiple sets of sensing values that characterize one or more radio signals received, during a respective sensing event, from an object in an environment of the wireless device. Multiple likelihood vectors may be obtained using the sensing values and characterizing a likelihood that the object is at a certain distance from the wireless device. A likelihood tensor may be generated, based on the likelihood vectors, that characterizes a likelihood that the object is moving along one of a set of trajectories. The likelihood tensor may be used to determine an estimate of the trajectory of the object.

Abstract: Implementations disclosed describe techniques and systems for efficient estimation of spatial characteristics of an outside environment of a wireless device. The disclosed techniques include generating multiple covariance matrices (CMs) representative of obtained sensing values. Different CMs may be associated with different frequency increments used in sensing signals to probe the outside environment. The disclosed techniques may further include determining eigenvectors for the CMs, and identifying, based on the determined eigenvectors, one or more spatial characteristics of the object in the outside environment.

Abstract: A method can include, by operation of a configuring device: storing user network information in the configuring device; receiving wireless communications from a target device; authenticating the target device; indicating a pointing direction for the configuring device; executing a wireless positioning operation with the target device to generate positioning data. In response to the configuring device being determined to be pointing at the target device, automatically configuring the target device for the user network with the stored user network information. Corresponding methods for a configuring device, as well as devices and systems are also disclosed.

Abstract: Disclosed are techniques to compensate frequency systematic known error (FSKE) in reflector or initiator radios using a hybrid RF-digital approach in multi-carrier phase-based ranging. The hybrid RF-digital approach combines a coarse frequency compensation technique in the RF domain and a fine frequency compensation technique in the digital domain to remove the FSKE across all carrier frequencies from a device. The coarse frequency compensation performed in the RF domain may use a PLL to multiply the crystal frequency to arrive close to a target carrier frequency to compensate for a coarse portion of the known FSKE at the target frequency. The fine frequency compensation may use digital techniques to remove the remaining portion of the known FSKE not compensated by the RF. The hybrid approach reduces the number of fractional bits in the multiplier of the PLL when compared to an approach that uses only the RF-PLL to remove the FSKE.

Abstract: A method can include determining a plurality of sample sets, each sample set being different from one another and including a plurality of frequencies separated by a uniform frequency range; wirelessly transmitting information identifying the sample sets for at least one remote device; for each sample set, transmitting a tone on each frequency of the sample set, receiving a tone on each frequency of the sample set from another device, and determining phase difference values for the received tones with respect to corresponding transmitted tones. From the phase shift values, a distance to the other device can be estimated. Corresponding devices and systems are also disclosed.

Abstract: An example method for estimating the angle-of-arrival (AoA) and other parameters of radio frequency (RF) signals that are received by an antenna array comprises: receiving a plurality of radio frequency (RF) signal power measurements by a plurality of antenna elements at a plurality of RF channels; computing, by applying a machine learning model to the plurality of RF signal power measurements, an estimated RF signal parameter value; and outputting the RF signal parameter value.

Abstract: A system and method for improving the accuracy of a secure phase-based ranging procedure and a Direction Finding procedure. The method includes receiving radio frequency signals from a second communication device. The method includes operating in a first mode including generating first location data based on the radio frequency signals and, transferring the first location data to a second processor in compliance with a Bluetooth Host Control Interface. The method includes comparing one or more conditions to one or more threshold values and responsive to the comparing transitioning from operating in the first mode to operating in a second mode. The method includes, while operating the second mode, generating second location data based on the radio frequency signals and, transferring the second location data to the second processor at a higher data transfer rate than the transferring of the first location data to the second processor.

Abstract: A multicarrier phase ranging system and method are provided. Generally, the method includes performing a handshake between first and a second transceiver to negotiate a list of channels and a start-time for a multicarrier phase ranging process. The process includes in a first cycle exchanging a Constant Tone (CT) between the first and second transceiver in a first epoch on a first channel, and processing the CT received in the first and second transceiver to measure a difference in phase between the CT received and a reference signal. The CT received is checked for interference using software or hardware in either or both of the first and second transceiver. If no interference is detected the first and second transceiver switch to another channel and exchange the CT at a next epoch. If interference is detected, at least one channel is skipped for at least a subsequent epoch.

Abstract: Disclosed are techniques to compensate frequency systematic known error (FSKE) in reflector or initiator radios using a hybrid RF-digital approach in multi-carrier phase-based ranging. The hybrid RF-digital approach combines a coarse frequency compensation technique in the RF domain and a fine frequency compensation technique in the digital domain to remove the FSKE across all carrier frequencies from a device. The coarse frequency compensation performed in the RF domain may use a PLL to multiply the crystal frequency to arrive close to a target carrier frequency to compensate for a coarse portion of the known FSKE at the target frequency. The fine frequency compensation may use digital techniques to remove the remaining portion of the known FSKE not compensated by the RF. The hybrid approach reduces the number of fractional bits in the multiplier of the PLL when compared to an approach that uses only the RF-PLL to remove the FSKE.