Abstract:
A system and method are disclosed that may provide an accurate estimate of the angle of arrival (AoA) of a wireless signal received by a device. The received wireless signal may include a plurality of signal components (702) associated with a number of different arrival paths. The device may generate a weighted signal, including a plurality of weighted signal components, by multiplying the plurality of signal components of the received wireless signal with a set of weighting values (704). The device may identify one or more of the weighted signal components associated with a first arrival path to the device (706), determine phase information of the one or more identified weighted signal components (708), and then determine the angle of arrival based, at least in part, on the determined phase information (710).
Abstract:
Techniques and systems described herein provide for improved clock drift calibration of two or more clocks of two or more wireless devices. According to one example method, a first packet is received at a first wireless device from a second wireless device sent at a first time. The method may also include determining a first time-of-arrival estimate for the first packet. The method may further include receiving, at the first wireless device, a second packet from the second wireless device sent at a second time. The method may also include determining a second time-of-arrival estimate for the second packet and determining a relative clock drift between the first wireless device and the second wireless device based at least in part on the first time-of-arrival estimate and the second time-of-arrival estimate.
Abstract:
Methods, systems, and devices are described for selecting data packets for forwarding in a vehicle network. In one example, a method includes receiving a first data packet at a first vehicle in a vehicular network and determining a geographic destination of the received first data packet. The method may also include forwarding the first data packet based at least in part on the geographic destination and a current wireless capacity of the vehicle network.
Abstract:
Methods, systems, and devices are described for operating a communications system using both licensed and unlicensed frequency bands. Unlicensed spectrum may be used as a primary band for transmitting data packets and TCP may be implemented for selectively transmitting (e.g., retransmitting) a subset of the transmitted data packets via licensed spectrum. Selective transmission of the subset of data packets via licensed spectrum may be based on a transmitter failing to receive and acknowledgment (ACK) message in response to one or more transmitted data packets on the unlicensed spectrum. Selective retransmission may be based on a transmitter detecting interference and/or it may be based on a receiver reporting information about channel conditions. In some cases, a transmitter may simultaneously receive channel condition information for both licensed and unlicensed spectrum. In other cases, unlicensed spectrum may be utilized for data packet transmission and licensed spectrum may be utilized for ACK messages.
Abstract:
Using location information of a multi-mode device (135-e) to determine whether to use at least a portion of a dedicated short range communications (DSRC) spectrum. Current location information of a multi-mode device is determined (705, 715). The multi-mode device is operating outside of the DSRC spectrum. The current location information is used to determine (720) whether the multi-mode device is located outside of geographical region (e.g. comprising a predetermined distance to a road) attributed to DSRC transmissions. Upon determining that the multi-mode device is located outside of the geographical region, at least a portion of the DSRC spectrum is used for transmissions by the multi-mode device (730, 735).
Abstract:
A UE receives information indicating a receive direction vector for a serving BS and a set of receive direction vectors for at least one interfering BS. The UE determines a channel between the UE and the serving BS and a set of channels between the UE and each of the at least one interfering BS. The UE determines a transmit direction vector to apply to modulated symbols for mapping to a set of resource blocks for an uplink transmission based on the channel, the set of channels, the receive direction vector, and the set of receive direction vectors. The UE determines an interference caused to the at least one interfering BS by the uplink transmission based on the transmit direction vector, the set of channels, and the set of receive direction vectors. The UE transmits information indicating the interference to the serving BS.
Abstract:
Techniques provided herein are directed toward addressing these and other issues by providing robust means for initializing an accelerometer that can take place even while a vehicle is in motion. Specifically, linear acceleration and velocity data can be estimated from wheel speeds, and angular velocity can be estimated with a gyroscope. The vehicle's acceleration can then be computed from these estimates, and subtracted from a total acceleration measured by the accelerometer to determine gravitational acceleration, which can then be accounted for in subsequent measurements taken by the accelerometer. A vehicle velocity may also be determined based on the vehicle's estimated angular velocity and linear velocity. Embodiments may also employ techniques for translating measurements taken in one coordinate frame to another coordinate frame for estimate determination and/or outlier compensation.
Abstract:
Techniques provide for accurately matching traffic signs observed in camera images with traffic sign data from 3D maps, which can allow for error correction in a position estimate of a vehicle based on differences in the location of the observed traffic sign and the location of the traffic sign based on 3D map data. Embodiments include preparing the data to allow for comparison between observed and map traffic sign data, conducting the comparison in a 2D frame (e.g., in the frame of the camera image) to make an initial order of proximity of candidate traffic signs in the map traffic sign data to the observed traffic sign, conducting a second comparison in a 3D frame (e.g. the frame of the 3D map) to determine an association based on the closest match, and using the association to perform error correction.
Abstract:
A method for ranging includes randomly selecting a symbol in each of at least two successive sub-cycles of a ranging cycle, transmitting symbol IDs corresponding to the randomly selected symbols and a sequence ID, and transmitting a ranging signal with the sequence ID on each of the randomly selected symbols.
Abstract:
The disclosure generally relates to position sensors, and more particularly to repair of carrier-phase cycle slips using displacement data. An apparatus for use in position sensing may include a displacement sensor, a positioning signal receiver, a memory, and a processor coupled to the displacement sensor, the positioning signal receiver, and the memory. The processor and memory may be configured to processor and memory are configured to detect a loss of lock of a first carrier tracking loop associated with the first set of carrier-phase measurements, wherein the first carrier tracking loop is associated with a first integer ambiguity, estimate, based on the displacement data, an ambiguity increment to the first integer ambiguity subsequent to the detected loss of lock, and resolve a second integer ambiguity associated with the second set of positioning signals based on the first integer ambiguity and the estimated ambiguity increment.