A communication device includes: a plurality of wireless communication sections, each of which is configured to wirelessly receive a signal from another communication device; and a control section configured to select a wireless communication section from which a specific reception time corresponding to an optimum parameter that is a reliability parameter indicating that the specific reception time is most appropriate for a processing target is detected, as a transmission communication section serving as a wireless communication section that transmits a signal from among the plurality of wireless communication sections, and configured to measure a distance between the transmission communication section and the other communication device on the basis of the specific reception time detected from a correlation computation result obtained from signals transmitted/received between the other communication device and the selected transmission communication section.

Techniques provided herein are directed toward enabling short-range proximity detection using radar sensors by reducing or eliminating OTA leakage. Embodiments generally include performing spatial cancellation by using a plurality of transmit/receive pairs of antenna elements to implement analog and/or digital leakage cancellation on the transmit and/or receive side. According to some embodiments null space projection cancellation, OTA leakage tracking, or adaptive minimum variance distortionless response (MVDR) beamforming may be performed to help preserve of the OTA leakage cancellation efficacy over time.

A communication device is configured to correlate a first signal with a second signal at a designated interval, the second signal corresponding to the first signal and being received by the communication device where the other communication device transmits a signal including a pulse as the first signal, convert a correlation computation result that is a result of correlating the first signal with the second signal at the designated interval into a format including a matrix product of an expanded modal matrix and an expanded signal vector, the expanded modal matrix including a plurality of elements indicating the correlation computation result obtained when assuming that the signals are received at respective set times, the expanded signal vector being a vector including a plurality of elements, each of which indicates whether or not there is a signal received at each of the set times and amplitude and phase of the signal.

A communication device includes: a plurality of wireless communication sections, each configured to be capable of wirelessly transmitting and receiving a signal to and from another communication device; and a control section configured to detect a specific element with regard to each of a plurality of correlation computation results that are obtained by correlating a first signal that is transmitted from the other communication device and that includes change in amplitude with respective second signals obtained when the plurality of wireless communication sections receive the first signal, calculate a reliability parameter that is an indicator indicating whether the detected specific element is appropriate for a processing target, and control a positional parameter determination process on the basis of the reliability parameter, the positional parameter determination process being a process of estimating a positional parameter indicating a position of the other communication device on the basis of the detected specific element.

A communication device includes: a plurality of wireless communication sections, each configured to be capable of wirelessly transmitting and receiving a signal to and from another communication device; and a control section configured to detect a specific element with regard to each of a plurality of correlation computation results that are obtained by correlating a first signal that is transmitted from the other communication device and that includes change in amplitude with respective second signals obtained when the plurality of wireless communication sections receive the first signal, calculate a reliability parameter that is an indicator indicating whether the detected specific element is appropriate for a processing target, and control a positional parameter determination process on the basis of the reliability parameter, the positional parameter determination process being a process of estimating a positional parameter indicating a position of the other communication device on the basis of the detected specific element.

A device implementing signal validation for secure ranging includes at least one processor configured to obtain a channel estimate based at least in part on a signal received from an other device over a channel. The at least one processor may be further configured to determine an average noise level of a beginning portion of the channel estimate and establish a direct path signal acceptance level for the channel estimate based at least in part on the average noise level. The at least one processor may further configured to identify a candidate direct path signal for the channel in a remaining portion of the channel estimate and validate the candidate direct path signal as a direct path signal for the channel when a signal level corresponding to the candidate direct path signal satisfies the direct path signal acceptance level, otherwise reject the candidate direct path signal as the direct path signal for the channel.

In a general aspect, a set of observed frequency-domain channel responses is filtered to remove noise or distortions that are not related to changes in the physical environment. In some aspects, for each frequency-domain channel response, a time-domain channel response is generated based on the frequency-domain channel response; and a filtered time-domain channel response is generated based on a constraint applied to the time-domain channel response. Additionally, a reconstructed frequency-domain channel response is generated based on the filtered time-domain channel response. An error signal is also generated, and a determination is made as to whether the error signal satisfies a criterion. The error signal can be indicative of a difference between the frequency-domain channel response and the reconstructed frequency-domain channel response. In response to each of the error signals satisfying the criterion, motion of an object in a space is detected based on the set of frequency-domain channel responses.

A communication system that includes a plurality of radio points is disclosed. Each radio point is configured to exchange radio frequency (RF) signals with a wireless device that transmits a Sounding Reference Signal (SRS) from a first physical location in a site; and extract at least one SRS metric from the SRS. The communication system also includes a baseband controller communicatively coupled to the plurality of radio points. The baseband controller is configured to determine a signature vector based on the at least one SRS metric from each of the plurality of radio points. The communication system also includes a machine learning computing system communicatively coupled to the baseband controller. The machine learning computing system is configured to use a machine learning model to determine location data for the first physical location of the wireless device based on the signature vector.

Methods, systems, and devices for wireless communications are described. A transmitting device (e.g., a user equipment (UE) or base station) may reduce a peak to average power ratio (PAPR) by clipping signals transmitted to a receiving device according to a clipping level. The receiving device may receive, from the transmitting device, an indication of the clipping level associated with a reference signal. The receiving device may receive the reference signal and identify distortions based on the clipping level. The receiving device may iteratively reconstruct peaks of the clipped reference signal until the receiving device is able to obtain accurate pilot symbols for use in channel estimation. The techniques described herein may enable receiving devices to improve efficiency and reliability of communications by improving channel estimation, which may increase the probability of successfully decoding transmitted information.

In some aspects, there is provided a method. The method may include estimating, based on a first signal-phase in a plurality of signal-phases associated with an input signal, a first channel impulse response; estimating, based on a second signal-phase in the plurality of signal-phases, a second channel impulse response; selecting, based on at least one characteristic of the estimated first channel impulse response and the estimated second channel impulse response, a signal-phase from the plurality of signal-phases; equalizing, based on the selected signal phase, the input signal to produce an equalized signal; and outputting, to a symbol detector, the equalized signal. Related systems, methods, and articles of manufacture are also disclosed.