Abstract: In a general aspect, a wireless communication channel is selected based on signal quality metrics. In some aspects, a first wireless communication device receives a first set of signals based on wireless signals transmitted through a space on a set of wireless communication channels from a second wireless communication device. A signal quality metric value is computed for each wireless communication channel based on the first set of signals, and one of the wireless communication channels is selected based on a comparison of the signal quality metric values for the respective wireless communication channels. The first wireless communication device receives a second set of signals based on wireless signals transmitted through the space on the selected wireless communication channel from the second wireless communication device, and a motion detection process is executed to detect motion of an object in the space based on the second set of signals.

Abstract: In a general aspect, a wireless communication channel is selected based on signal quality metrics. In some aspects, a first wireless communication device receives a first set of signals based on wireless signals transmitted through a space on a set of wireless communication channels from a second wireless communication device. A signal quality metric value is computed for each wireless communication channel based on the first set of signals, and one of the wireless communication channels is selected based on a comparison of the signal quality metric values for the respective wireless communication channels. The first wireless communication device receives a second set of signals based on wireless signals transmitted through the space on the selected wireless communication channel from the second wireless communication device, and a motion detection process is executed to detect motion of an object in the space based on the second set of signals.

Abstract: In a general aspect, a wireless communication channel is selected based on signal quality metrics. In some aspects, a first wireless communication device receives a first set of signals based on wireless signals transmitted through a space on a first wireless communication channel from a second wireless communication device. A signal quality metric value is computed based on the first set of signals, and a second wireless communication channel is selected based on a determination that the value of the signal quality metric does not meet a quality criterion for a motion detection process. The first wireless communication device receives a second set of signals based on wireless signals transmitted through the space on the second wireless communication channel from the second wireless communication device, and the motion detection process is executed to detect motion of an object in the space based on the second set of signals.

Abstract: In some aspects, a wireless-signal source locator system includes wireless sensor devices distributed at distinct locations over a geographic region. The wireless sensor devices are configured to passively monitor wireless communication network signals in the geographic region. Each wireless sensor device is configured to receive a source signal wirelessly transmitted by a source (e.g., a mobile device, etc.) and a reference signal (e.g., from a synchronization source). The wireless sensor devices can generate arrival-time data based on the source signal and the reference signal. The wireless-signal source locator system further includes a data analysis system configured to receive the arrival-time data from the wireless sensor devices and to identify a location of the source based on analyzing the arrival-time data generated by three or more of the wireless sensor devices.

Abstract: In a general aspect, motion detected using wireless signals is categorized. In some aspects, frequency response signals are obtained. The frequency response signals are based on wireless signals that were transmitted through a space and received at a wireless sensor device over a time period. Values of a statistical parameter are determined for the time period, with the statistical parameter for the time period being based on a function applied to frequency components of the frequency response signals over the time period. A category of motion that occurred in the space during the time period is identified based on the values of the statistical parameter.

Abstract: In some aspects, a wireless monitoring system includes a sensor network, a data analysis system and a communication interface. The sensor network includes wireless sensor devices configured to passively monitor radio frequency (RF) signals exchanged in a wireless communication network in a geographic region, and each wireless sensor device is configured to compute local network-usage parameters based on processing the RF signals detected by the wireless sensor device. The data analysis system is configured to analyze regional performance metrics of the wireless communication network based on the local network-usage parameters computed by the biosensor devices. In some instances, the communication interface is configured to transmit a network performance report to the wireless communication network based on the analysis of the regional performance metric.

Abstract: In a general aspect, a motion detection channel is operated in a wireless communication network. In some aspects, a first wireless network device communicates wireless network traffic on a first subset of wireless communication channels in a wireless communication network. The first wireless network device receives motion detection signals transmitted through a space by a second wireless network device. The motion detection signals are received on a second subset of wireless communication channels. The motion detection signals are processed to detect motion of an object in the space.

Abstract: In some aspects, a wireless-signal source locator system includes wireless sensor devices distributed at distinct locations over a geographic region. The wireless sensor devices are configured to passively monitor wireless communication network signals in the geographic region. Each wireless sensor device is configured to receive a source signal wirelessly transmitted by a source (e.g., a mobile device, etc.) and a reference signal (e.g., from a synchronization source). The wireless sensor devices can generate arrival-time data based on the source signal and the reference signal. The wireless-signal source locator system further includes a data analysis system configured to receive the arrival-time data from the wireless sensor devices and to identify a location of the source based on analyzing the arrival-time data generated by three or more of the wireless sensor devices.

Abstract: In some aspects, a wireless-signal source locator system includes wireless sensor devices distributed at distinct locations over a geographic region. The wireless sensor devices are configured to passively monitor wireless communication network signals in the geographic region. Each wireless sensor device is configured to receive a source signal wirelessly transmitted by a source (e.g., a mobile device, etc.) and a reference signal (e.g., from a synchronization source). The wireless sensor devices can generate arrival-time data based on the source signal and the reference signal. The wireless-signal source locator system further includes a data analysis system configured to receive the arrival-time data from the wireless sensor devices and to identify a location of the source based on analyzing the arrival-time data generated by three or more of the wireless sensor devices.

Abstract: In a general aspect, motion of an object is detected based on wireless signals. In some aspects, wireless signals based on a repeated wireless transmission are received at a wireless sensor device in a space. The received wireless signals are analyzed, by operation of a processor, to detect movement of an object in the space. The analysis includes determining complex values representing the relative phases and amplitudes of respective frequency components of each of the received wireless signals, and detecting movement of an object in the space based on a change in the complex values.

Abstract: In some aspects, a wireless monitoring system includes a sensor network, a data analysis system and a communication interface. The sensor network includes wireless sensor devices configured to passively monitor radio frequency (RF) signals exchanged in a wireless communication network in a geographic region, and each wireless sensor device is configured to compute local network-usage parameters based on processing the RF signals detected by the wireless sensor device. The data analysis system is configured to analyze regional performance metrics of the wireless communication network based on the local network-usage parameters computed by the biosensor devices. In some instances, the communication interface is configured to transmit a network performance report to the wireless communication network based on the analysis of the regional performance metric.

Abstract: In some aspects, a wireless-signal source locator system includes wireless sensor devices distributed at distinct locations over a geographic region. The wireless sensor devices are configured to passively monitor wireless communication network signals in the geographic region. Each wireless sensor device is configured to receive a source signal wirelessly transmitted by a source (e.g., a mobile device, etc.) and a reference signal (e.g., from a synchronization source). The wireless sensor devices can generate arrival-time data based on the source signal and the reference signal. The wireless-signal source locator system further includes a data analysis system configured to receive the arrival-time data from the wireless sensor devices and to identify a location of the source based on analyzing the arrival-time data generated by three or more of the wireless sensor devices.

Abstract: In some aspects, a wireless-spectrum analysis technique includes obtaining, at a computer system, a simulated spatial distribution of a wireless signal parameter (e.g., spectral power). The simulated spatial distribution is based on a computer-simulation of wireless signal propagation in a geographic region. A measured spatial distribution of the wireless signal parameter is obtained at the computer system. The measured spatial distribution is based on measurements performed by wireless sensor devices in the geographic region. Each of the wireless sensor devices is configured to provide local parameter measurements based on wireless signals detected by the wireless sensor device. The simulated spatial distribution is compared with the measured spatial distribution. In some instances, the simulated spatial distribution geographic region is modified based on the comparison.

Abstract: A pre-distortion method. A signal to be transmitted Tx is pre-distorted to compensate for nonlinearities of a transmitter. The pre-distorted signal is filtered by an EBEE filter and a baseband filter. The EBEE filter has a filter characteristic of that cancels the baseband filter response over the range of frequencies from a first corner frequency of the baseband filter to a frequency of N*fB where N is a highest order of distortion component being cancelled and fB is the bandwidth of the original signal to be transmitted. This abstract is not to be considered limiting, since other embodiments may deviate from the features described in this abstract.

Abstract: A system and method of pre-distorting a signal applied to a power amplifier to compensate for distortion introduced by the power amplifier at different power settings, comprising pre-distorting the signal according to a pre-distortion polynomial, prior to amplification of the signal by the power amplifier; adaptively estimating and applying pre-distortion polynomial coefficients to the pre-distorter by saving successive iterations of adaptive estimation of the pre-distortion polynomial coefficients; and regularizing estimation of the pre-distortion polynomial coefficients over successive iterations according to a modified objective function that initially constrains growth in the magnitude of the pre-distortion polynomial coefficients and then relaxes the constraint in growth over successive iterations until estimation is reduced to a steady-state least squares estimation.

Abstract: In some aspects, a method of displaying wireless-spectrum usage information is described. In some examples, a surface plot of a measure of wireless-spectrum usage for a geographic region is generated. The surface plot is based on analysis of physical layer signals detected at wireless-spectrum monitoring locations distributed over the geographic region. The surface plot is superimposed onto a view of the geographic region by operation of a display device. The superimposed surface plot visually indicates values for the measure of wireless-spectrum usage over the view of the geographic region.

Abstract: In some aspects, a wireless-spectrum analysis system is described. In some examples, the wireless-spectrum analysis system includes wireless-spectrum analysis devices distributed at distinct locations over a geographic region. The wireless-spectrum analysis devices are configured to concurrently monitor wireless-spectrum usage at each distinct location. Each wireless-spectrum analysis device is configured to transmit, from the wireless-spectrum analysis device, spectral-usage parameters identified by the wireless-spectrum analysis device based on wireless signals detected by the wireless-spectrum analysis device at its distinct location. The wireless-spectrum analysis system further includes a data aggregation system configured to aggregate the spectral-usage parameters transmitted from the wireless-spectrum analysis devices.

Abstract: A pre-distortion method. A signal to be transmitted Tx is pre-distorted to compensate for nonlinearities of a transmitter. The pre-distorted signal is filtered by an EBEE filter and a baseband filter. The EBEE filter has a filter characteristic of that cancels the baseband filter response over the range of frequencies from a first corner frequency of the baseband filter to a frequency of N*fB where N is a highest order of distortion component being cancelled and fB is the bandwidth of the original signal to be transmitted. This abstract is not to be considered limiting, since other embodiments may deviate from the features described in this abstract.

Abstract: A speed parameter or channel quality parameter are determined in a mobile device based on variation in frequency offset measurement. A higher variation in the frequency offset measurement reflects a poorer channel quality and a higher speed; a lower variation in the frequency offset measurement reflects a better channel quality and a lower speed. The parameter(s) may be fed back to the system and used, for example, to make adaptive modulation and coding decisions.

Abstract: A system and method for method of pre-distorting a signal applied to a power amplifier to compensate for distortion introduced by the power amplifier at different power settings, comprising pre-distorting the signal according to a pre-distortion polynomial, prior to amplification of the signal by the power amplifier; adaptively estimating and applying pre-distortion polynomial coefficients to the pre-distorter by saving successive iterations of adaptive estimation of the pre-distortion polynomial coefficients; and regularizing estimation of the pre-distortion polynomial coefficients over successive iterations according to a modified objective function that initially constrains growth in the magnitude of the pre-distortion polynomial coefficients and then relaxes the constraint in growth over successive iterations until estimation is reduced to a steady-state least squares estimation.