This disclosure pertains to a method for operating a first radio node (100) in a radio access network. The method comprises performing a calibration of the first radio node (100) based on calibration signaling received from a second radio node (200) and based on calibration configuration information, the calibration configuration information being received from the second radio node (200). The disclosure also pertains to related devices and methods.

The present invention relates to a method for testing the accuracy of the automatic positioning means of a signal tracking antenna during a satellite signal searching and/or tracking operation; wherein the platform, such as a ship, on which the signal tracking antenna is mounted is kept stationary during the testing operation. The method includes the use of an unmanned aerial vehicle and a control station.

An ultra-wideband (UWB) communication system comprising a transmitter and a receiver having two antennas. An UWB signal transmitted by the transmitter is received at each of the antennas. By comparing the carrier phases of the received signals, the phase difference can be determined. From this phase difference and the known distance, d, between the antennas, the Cartesian (x, y) location of the transmitter relative to the receiver can be directly determined.

An ultra-wideband (UWB) communication system comprising a transmitter and a receiver having two antennas. An UWB signal transmitted by the transmitter is received at each of the antennas. By comparing the carrier phases of the received signals, the phase difference can be determined. From this phase difference and the known distance, d, between the antennas, the Cartesian (x, y) location of the transmitter relative to the receiver can be directly determined.

An ultra-wideband (UWB) communication system comprising a transmitter and a receiver having two antennas. An UWB signal transmitted by the transmitter is received at each of the antennas. By comparing the carrier phases of the received signals, the phase difference can be determined. From this phase difference and the known distance, d, between the antennas, the Cartesian (x, y) location of the transmitter relative to the receiver can be directly determined.

An ultra-wideband (UWB) communication system comprising a transmitter and a receiver having two antennas. An UWB signal transmitted by the transmitter is received at each of the antennas. By comparing the carrier phases of the received signals, the phase difference can be determined. From this phase difference and the known distance, d, between the antennas, the Cartesian (x, y) location of the transmitter relative to the receiver can be directly determined.

A mobile robot includes a chassis, a shell moveably mounted on the chassis, and a cutting assembly mounted to the chassis. The mobile robot also includes a communication system that includes an antenna module disposed on a rear portion of the mobile robot. The antenna module includes a base assembly, and an antenna assembly mounted to the base assembly by a spring. The antenna assembly includes a ranging antenna, and at least three angle antennas arranged axisymmetrically about the ranging antenna, such that the ranging antenna and the three angle antennas define a tetrahedral geometry for determining an angle of arrival for one or more incident signals.

Systems, methods, and apparatus to process audio signals based on a number of listeners are disclosed. An example implementation involves a playback device processing, via an audio processing component, an audio signal for playback according to a first audio characteristic. While processing the audio signal for playback according to the first audio characteristic, the playback device detects, via a location component, a number of listeners in a listening area. The playback device determines a second audio characteristic based on the detected number of listeners in the listening area, and after determining the second audio characteristic, processes, via the audio processing component, the audio signal for playback according to the second audio characteristic.

A method and apparatus are provided for calibrating a wireless access point comprising an array of multiple (m) antennas denoted A.sub.i (i=1 . . . m), each antenna having a respective internal phase offset i. The method comprises receiving a signal from at least one transmitter located at a substantially known bearing from the wireless access point. The method further comprises determining an estimated value for each internal phase offset.sub.i such that an angle of arrival (AoA) spectrum calculated for the received signal on the basis of said estimated values matches the known bearing, wherein said AoA spectrum is calculated by treating said multiple antennas as a phased array. A method and an apparatus are also provided for calibrating a wireless access point comprising first and second arrays of multiple antennas, each antenna array having a respective radio unit, and each antenna in an array having a respective internal phase offset.sub.i. The method comprises using an antenna in the first antenna array to act as a transmitter located at a known distance from each antenna in the second antenna array, such that a signal from said transmitter is received at each antenna in the second antenna array. A phase for the received signal at each antenna in the second antenna array is measured in the radio unit, while an expected phase for the received signal is calculated, for each antenna in the second antenna array, based on the known distance of that antenna from the transmitter. The internal phase offset.sub.i, for each antenna in the second antenna array can then be determined from the difference between the measured phase and the calculated phase for that antenna.

A radio receiver is made much more immune to jamming signals. A vector EM sensor, in a 2-dimensional (3-axis sensor) or 3-dimensional (6-axis sensor) sensor configuration, is combined with a unique digital rotation to a preferred direction to create a new reference channel and, using an advanced frequency domain noise mitigation algorithm or other noise cancellation algorithm, can effectively reject jamming and other interference signals and improve the signal-to-noise ratio (20-40 dB) and the receiving performance of the receiver. The method can cancel both near-field and far-field interference and improve accuracy for various applications concerned with establishing the direction, or bearing, to a source. A communication receiver with the vector sensor and the cancellation algorithm has unique anti-jamming capabilities even for multiple jamming sources.