A multi-port antenna and associated systems having extremely wide bandwidth and capable of maintaining directivity as frequency decreases and is made arbitrarily low, allowing DF systems to operate to arbitrarily low frequency regardless of size. Construction may be rugged, lightweight, and low cost, allowing reliable service in harsh environments. The systems allow utilization of both the E and H fields occupying a common area of space. The disclosed DF system takes advantage of knowledge of the as-installed array manifold, uses pattern matching to determine the angle of arrival (AoA) of incoming waves, and enhances sensitivity by using integration on cross-correlation products between the multiple ports to achieve SNR improvement.

A system and a method for signal sensing are provided. The system for signal sensing includes a sensing device, a processor and a time server coupled to the sensing device. The sensing device includes a plurality of receivers and an oscillator coupled to the receivers. The receivers are synchronized by receiving a time synchronization signal from the time server. The receivers monitor a plurality of signals of an object according to a clock generated by the oscillator and obtains a plurality of channel state information (CSI) according to the signals. The processor calculates an angle of arrival of the signals according to the CSI.

A system and a method for signal sensing are provided. The system for signal sensing includes a sensing device, a processor and a time server coupled to the sensing device. The sensing device includes a plurality of receivers and an oscillator coupled to the receivers. The receivers are synchronized by receiving a time synchronization signal from the time server. The receivers monitor a plurality of signals of an object according to a clock generated by the oscillator and obtains a plurality of channel state information (CSI) according to the signals. The processor calculates an angle of arrival of the signals according to the CSI.

Devices and methods of estimating the AoD of a STA are generally described. The STA receives comparison symbols from a first AP antenna. The comparison symbols are received prior to and after switching of transmitter chains from a first set of antennas to a second set of antennas. AoD symbols are received immediately after the comparison symbols. A phase and amplitude correction is determined based on a phase and amplitude change between the comparison symbols and the second AoD symbol corrected based thereon. The AoD is subsequently estimated based on the symbol measurements.

A positioning sensor includes m receiving antennas connected to a feeder circuit and n variable loads, and a receiver that receives a first signal via the m receiving antennas. The positioning sensor further includes a memory that stores a first signal strength value of a first signal that the receiver receives when a variable load varies in value, and a processor that calculates a second signal strength value from a complex propagation channel, searches for a complex propagation channel candidate that has a minimum difference between a first signal strength and a second signal strength, determines the complex propagation channel candidate to be a complex propagation channel when the receiver receives the first signal, and estimates an incoming direction of the first signal from the determined complex propagation channel.

A positioning sensor includes m receiving antennas connected to a feeder circuit and n variable loads, and a receiver that receives a first signal via the m receiving antennas. The positioning sensor further includes a memory that stores a first signal strength value of a first signal that the receiver receives when a variable load varies in value, and a processor that calculates a second signal strength value from a complex propagation channel, searches for a complex propagation channel candidate that has a minimum difference between a first signal strength and a second signal strength, determines the complex propagation channel candidate to be a complex propagation channel when the receiver receives the first signal, and estimates an incoming direction of the first signal from the determined complex propagation channel.

Systems and techniques are provided for indoor positioning for mobile devices. An orientation of a mobile device may be determined. An angle of a line-of-sight between the mobile device and the base station may be determined based on a peak received signal strength of a signal from the base station at a beamforming antenna of the mobile device. A distance between the mobile device and the base station may be determined based on the peak received signal strength. The mobile device may calculate the location of the mobile device using the measured orientation, the angle of the line-of-sight, and the distance between the mobile device and the base station, and a location of the base station.

Single antenna direction finding is performed by physically moving a device to different device positions. As the device is physically moved, signal processing hardware within the device is used to make a plurality of signal response measurements of a signal detected by a single antenna of the device. The signal emanates from an object. The plurality of signal response measurements are made by sampling signal response at a plurality of sample times. A means for 3-dimensional positioning makes a plurality of inertial measurements at the plurality of sample times. The plurality of signal response measurements and the plurality of inertial measurements are used to produce a virtual response array vector. The virtual response array vector is used to calculate a direction of arrival from the object to the device.

Provided is a displacement measurement device including: a radio wave transmitter installed at a measurement position, which is configured to transmit radio waves of a plurality of frequencies from a transmission antenna; and a radio wave receiver installed at a fixed position. The radio wave transmitter includes: a plurality of reception antennas each configured to output received signals indicating the results of receiving the radio waves of the plurality of frequencies; a relative phase combining unit configured to combine, for the plurality of frequencies, relative phases between the plurality of reception antennas; a relative phase shifting unit configured to shift the relative phase between the plurality of frequencies, which is combined by the relative phase combining unit; and a positioning calculation unit configured to calculate the positioning value of the transmission antenna based on the relative phase shifted by the relative phase shifting unit.

A ground antenna determines the current time and its own position from received signals that were transmitted by artificial earth satellites for communication. A high-gain multi-beam electrically-steered antenna is combined with a processing system to measure the angles between two or more satellites and determine the present distance to each satellite by the information broadcast on the TT&C channel. The knowledge of the angles and distances, as well as the trajectory of the satellites, can be combined with their locations as predicted by the satellite ephemeris data to triangulate the location of the receiver. This system is different from conventional GPS antennas because it does not require the cooperation of active communication with the satellites to derive a location estimate. The location is computed by the ground terminal, not by the satellite. This system can be used in cases where other locating services are offline, jammed, or otherwise unavailable to maintain location and time synchronization.