Abstract:
Disclosed are methods, devices, systems, apparatus, servers, computer- / processor-readable media, and other implementations, including a method of estimating a range between a first wireless device and a second wireless device that includes obtaining, at the first wireless device, first information related to a first broadcast message transmitted by the first wireless device, and obtaining, at the first wireless device, second information related to a second broadcast message transmitted by the second wireless device, with the second broadcast message including at least some of the first information. The method also includes determining the range between the first wireless device and the second wireless device based, at least in part, on the first information and the second information.
Abstract:
Disclosed are implementations that include a method, at a mobile device, including receiving multiple broadcast messages transmitted by multiple stationary wireless devices, and obtaining first information relating to each of the multiple broadcast messages, with at least some of the first information being included in the multiple broadcast messages, and second information relating to at least one earlier broadcast communication received by at least one of the multiple stationary wireless devices, prior to transmission of the at least one of the multiple broadcast messages, from at least one other of the multiple stationary wireless devices, with the second information included in the at least one of the multiple broadcast messages. The method also include determining location information for the mobile device based on the first information, the second information, and known positions of at least some of the multiple stationary wireless devices.
Abstract:
A method, an apparatus, and a computer program product for wireless communication are provided. The apparatus receives a first message from a first wireless communication device and a second message from a second wireless communication device, obtains information associated with a first processing delay with respect to the first message and a second processing delay with respect to the second message, and transmits a third message comprising an indication of the information associated with the first and second processing delays.
Abstract:
Systems and methods are disclosed that may determine phase offsets in wireless devices. In accordance with some embodiments, a phase of a local oscillator signal associated with transmission of data from a wireless device may be measured by generating a reference signal having a frequency that is a selected integer value times a frequency of a baseband clock signal, generating the local oscillator (LO) signal to have a frequency substantially equal to a carrier frequency of the data transmission, and mixing the reference signal and the LO signal to generate a mixed signal indicative of the phase of the LO signal.
Abstract:
A range between a first wireless device and a second wireless device is estimated using a first mechanism based on messages transmitted over a first communication channel. The first communication channel is associated with a first radio access technology capability of the wireless devices. One or more metrics indicative of an accuracy of the range estimates provided by the first mechanism are obtained. A second mechanism to estimate a range between the first wireless device and the second wireless device may be implemented in favor of the first mechanism when the metric fails to satisfy a criterion. The second mechanism is based on unicast messages transmitted over a second communication channel. The second communication channel is associated with a second radio access technology capability of the wireless devices and may be the same as, or different from, the first communication channel.
Abstract:
A method for aligning visual-inertial odometry (VIO) and satellite positioning system (SPS) reference frames includes obtaining a plurality of range-rate measurements of a mobile platform from an SPS. The range-rate measurements are with respect to a global reference frame of the SPS. The method also includes obtaining a plurality of VIO velocity measurements of the mobile platform from a VIO system. The VIO velocity measurements are with respect to a local reference frame of the VIO system. At least one orientation parameter is then determined to align the local reference frame with the global reference frame based on the range-rate measurements and the VIO velocity measurements.
Abstract:
A method, an apparatus, and a computer program product for wireless communication are provided. The device may receive a signal on each of N channels from another device. The N channels may include a first channel. The device may determine a frequency response of each of the N channels based on the received signals. The device may transform, from a frequency domain to a time domain, the N frequency responses in order to generate a transformed signal. The frequency response of an nth channel of the N channels may be adjusted by a channel offset of the nth channel with respect to the first channel for n being each integer from 2 to N. The device may then estimate the channel offset for each of the N channels other than the first channel based on the transformed signal.
Abstract:
Methods, systems, and devices are described for wireless communications at a wireless device. A wireless device may adaptively select a parity check matrix to increase the reliability of signal transmission by adapting to different channel statistics and channel types (e.g., erasure channels, channels with additive white Gaussian noise, and channels with discrete or continuous alphabets). For example, polarization codes (i.e., codes based on rows of a polarization matrix) may be used to construct parity check matrices on-the-fly given an estimation of dynamic channel conditions or diverse channel structures. The channel may be decomposed into polarized sub-channels corresponding to the polarization codes, and mutual information profiles may be determined for each of the polarized sub-channels. The parity check matrix corresponding to the polarization codes may be constructed based on the mutual information profile of all polarized sub-channels. The wireless device may encode or decode data based on the constructed parity check matrix.
Abstract:
Disclosed embodiments pertain to a method on a UE may comprise determining a first absolute position of the UE at a first time based on GNSS measurements from a set of satellites. At a second time subsequent to the first time, the UE may determine a first estimate of displacement of the UE relative to the first absolute position using non-GNSS measurements. Further, at the second time, the UE may also determine a second estimate of displacement relative to the first absolute position and/or a second absolute position of the UE based, in part, on: the GNSS carrier phase measurements at the first time from the set of satellites, and GNSS carrier phase measurements at the second time from a subset comprising two or more satellites of the set of satellites, and the first estimate of displacement of the UE.
Abstract:
Clock drift for range estimation between a first wireless device and a second wireless device is determine before such estimation, while acceptable communication between the first device and the second device is unavailable. While acceptable communication is unavailable, a relative clock drift Δ01 between a relative wireless device and the first device is obtained by the second device; a relative clock drift Δ20 between the second device and the relative wireless device is determined; and a relative clock drift Δ21 between the second device and the first device is estimated based on the relative clock drift Δ01 and the relative clock drift Δ20. Once acceptable communication is available, a distance between the first device and the second device is estimated based on the relative clock drift Δ21.