A measuring device comprises a processing unit, a first antenna adapted to receive a first signal, and a second antenna, adapted to receive a second signal. The processing unit comprises a baseline unit adapted to determine a baseline variance of a first variable and/or a second variable. Moreover, it comprises a variance unit adapted to determine a variance of the first variable and/or the second variable. The first variable and the second variable are each at least initially derived from at least the first signal and the second signal. The processing unit furthermore comprises an error unit, adapted to determine if a systematic error is present, based on the baseline variance and the variance of the first variable and/or the second variable.

This invention is present an iterative method for joint antenna array calibration and direction of arrival estimation using millimeter-wave (mm-Wave) radar. The calibration compensates for array coupling, phase, and gain errors and does not require any training data. This method is well suited for applications where multiple antenna elements are packaged in a chip and where offline calibration is either expensive or is not possible. This invention is also effective when the array coupling is a function of direction of arriving waves from the object. It is also applicable to any two-dimensional array shape. Real experiment results demonstrate the viability of the algorithm using real data collected from a four-element array.

In an ultra-wideband (UWB) receiver, a received UWB signal is periodically digitized as a series of ternary samples. During a carrier acquisition mode of operation, the samples are continuously correlated with a predetermined preamble sequence to develop a correlation value. When the value exceeds a predetermined threshold, indicating that the preamble sequence is being received, estimates of the channel impulse response (CIR) are developed. When a start-of-frame delimiter (SFD) is detected, the best CIR estimate is provided to a channel matched filter (CMF). During a data recovery mode of operation, the CMF filters channel-injected noise from the sample stream. Both carrier phase errors and data timing errors are continuously detected and corrected during both the carrier acquisition and data recovery modes of operation. The phase of the carrier can be determined by accumulating the correlator output before it is rotated by the carrier correction. By comparing the carrier phases of two receivers separated by a known distance, d, the angle of incidence, , of the signal can be determined.

A direction finding system for finding the angle of arrival of a target signal from a transmitter. The system includes a plurality of directional antennas positioned to face different directions for receiving the target signal. The antennas are mounted as an antenna array on a rotatable mount for supporting and rotating the antenna array. A receiver unit down converts the RF target signal to IF signals that are digitized by an A/D converter providing digital values. A computer computes the power in the signals from the A/D samples. A computer stores calibration information for the directional antennas, processes the digital values and the calibration information to determine a rotation angle for rotating the antennas to provide new digital values, processes the new digital values and the calibration information to determine an intersection angle, and subtracts the rotation angle from the intersection angle to determine the final value for the angle of arrival of the target signal.

Example techniques relate to playback based on acoustic signals in a system including a first network device and a second network device. A first network device may detect a presence of a user using a camera and/or infrared sensors. The first network device sends, in response to detecting the presence of the user, a particular signal via the first network interface. The second network device receives data corresponding to the particular signal and plays back an audio output corresponding to the particular signal.

Example techniques relate to playback based on acoustic signals in a system including a first network device and a second network device. A first network device may detect a presence of a user using a camera and/or infrared sensors. The first network device sends, in response to detecting the presence of the user, a particular signal via the first network interface. The second network device receives data corresponding to the particular signal and plays back an audio output corresponding to the particular signal.

Example techniques relate to playback based on acoustic signals in a system including a first network device and a second network device. A first network device may detect a presence of a user using a camera and/or infrared sensors. The first network device sends, in response to detecting the presence of the user, a particular signal via the first network interface. The second network device receives data corresponding to the particular signal and plays back an audio output corresponding to the particular signal.

Example techniques relate to playback based on acoustic signals in a system including a first network device and a second network device. A first network device may detect a presence of a user using a camera and/or infrared sensors. The first network device sends, in response to detecting the presence of the user, a particular signal via the first network interface. The second network device receives data corresponding to the particular signal and plays back an audio output corresponding to the particular signal.

A system and method of detecting a plurality of emitters in a single snapshot. The system includes an antenna that is operable to emit a beamwidth to intercept output signals emitted by a plurality of emitters in a search area. The system also includes a processor that is operable with the antenna for receiving the output signals. The system also includes at least one non-transitory machine readable medium that is operable to be accessed by the processor. The system also includes a computer program product that has instructions stored on the at least one non-transitory machine readable medium, wherein when the computer program product is executed by the processor, a process is carried out by the processor for detecting the plurality of emitters inside of the beamwidth of the direction finding antenna in a single snapshot.

Techniques for implementing an MDM platform with a P2P mesh network are disclosed. This MDM platform uses a dashboard to facilitate the control of the devices/peers in the P2P mesh network. This network includes: (i) a service, (ii) a first device, and (iii) a second device. The first device is connected to the service by way of a first P2P mesh network connection between the first device and the service. The second device is connected to the service by way of (i) a second P2P mesh network connection between the second device and the first device and (ii) the first P2P mesh network connection between the first device and the service. Data is transmitted using those connections. A dashboard displays the data. The dashboard can also be used to trigger MDM commands to any device in the P2P mesh network, including those that are not connected to the Internet.