An apparatus and method for estimating a direction of an RF signal are provided. The apparatus includes an antenna unit, a preliminary correction unit, a signal processing unit, a conversion unit, and a signal direction estimation unit. The antenna unit receives an RF signal from at least one antenna. The preliminary correction unit performs preliminary correction depending on whether the at least one antenna is an antenna having directional gain. The signal processing unit generates an analog signal by performing a frequency shift on the RF signal or a signal on which the preliminary correction has been performed. The conversion unit converts the analog signal into a digital sample. The signal direction estimation unit extracts the phase of the antenna from the digital sample, and estimates the direction of the RF signal based on the extracted phase.

Techniques are presented herein for improving location determination of a wireless device in environments where there can be multipath issues. A wireless device having a plurality of antennas receives a wireless transmission from a target device whose location is to be determined. Channel state information data is generated based on reception of the transmission at the plurality of antenna. The channel state information data is separated or partitioned into subcarrier group specific data for each of a plurality of groups of subcarriers within a bandwidth of the received transmission. Location probability data is computed for each of the plurality of groups of subcarriers from the subcarrier group specific data for respective ones of the plurality of groups of subcarriers. The location probability data for the plurality of groups of subcarriers is combined to produce aggregate location probability data, from which a location of the target device is determined.

Techniques are presented herein for improving location determination of a wireless device in environments where there can be multipath issues. A wireless device having a plurality of antennas receives a wireless transmission from a target device whose location is to be determined. Channel state information data is generated based on reception of the transmission at the plurality of antenna. The channel state information data is separated or partitioned into subcarrier group specific data for each of a plurality of groups of subcarriers within a bandwidth of the received transmission. Location probability data is computed for each of the plurality of groups of subcarriers from the subcarrier group specific data for respective ones of the plurality of groups of subcarriers. The location probability data for the plurality of groups of subcarriers is combined to produce aggregate location probability data, from which a location of the target device is determined.

There are provided a method of locating a transmitting source in multipath environment and system thereof. The method comprises: obtaining, by each receiver k of a plurality of spatially separated receivers, a sequence of samples of a signal received by the receiver, each sample respectively associated with a time of obtaining said sample, wherein one or more receivers m among the plurality of receivers k each obtain a respective sequence of samples over a plurality of different positions along a respective trajectory r(t) with respect to the site associated with the respective receiver m; and processing the obtained sequences of samples to identify the most likely location of the transmitting source. Optionally, most likely location can be estimated using a grid of potential locations within an area of interest.

A system and a method, as well as a positioning and wearable devices for determining the distance and position of devices communicating with each other over a medium, the system, are disclosed. At least one remote device comprises first processing unit, at least one transmitter functionally connected to the first processing unit and adapted to transmit signals over a medium, and at least one receiver functionally connected to the first processing unit and adapted to receive signals over said medium. At least two wearable devices, each comprising a second processing unit and wireless communication means capable of receiving and sending data signals over said medium, are also provided. The remote device is adapted to determine the distance to at least two wearable devices, to determine the direction to said at least two wearable devices based on at least two different bearings taken from said at least one remote device to each wearable device, to calculate the position of said at least two wearable devices relative to the remote device, and to communicate the position of at least one first wearable device to a second wearable device. The wearable devices are adapted to process the position of a first wearable device in their processing unit and to present to the user of a second wearable device an indication of direction and distance to said first wearable device.

A lighting network includes a plurality of nodes, each having a node identifier. Each node includes a light source and a radio-frequency (RF) transceiver that transmits RF signals to and receives RF signals from other ones of the nodes. Each signal includes a data packet having a packet identifier, a destination node identifier and a payload. Each node compares the packet identifier of a received packet to a list of packets identifiers and when the packet identifier is not in the list, adds the packet identifier to the list. If the node is the destination node for the packet, the node then executes a command contained in the payload of the packet. If the node is not the destination node, the node retransmits the packet to the nodes that are within range of the RF transceiver. When the packet is in the list, the node discards the packet.

Determining a location of a user device comprises a wireless computing system supported by an access point. The wireless computing system receives a signal from the user device. The system estimates a location of the user device based on RSSI and calculates a boundary around the estimated location. The wireless computing system selects a plurality of sections inside of the boundary and performs a coarse calculation of a location of the user device based on an angle of arrival of the received signal. The system determines sections of the plurality of sections that have results from the coarse calculation that are more likely to be a location of the user device. The system performs a fine calculation of the location based on the angle of arrival of the received signal within each of the sections. The system identifies a particular section as the location of the user device.

A method to automatically and continuously provide surveillance based on central and/or distributed surveillance of presence, positions, movements and movement pattern of one or more vessels in narrow waters, a sailing lane or where danger of collision with other vessels or other fixed or floating objects may occur. A vessel emits a sweeping signal that repeatedly hits one or more detectors, which detect the character of the sweeping signal and the time intervals between the signal hits on the respective detector. The exact position of the vessel and/or movements is calculated at least on the basis of trigonometric principles, and the vessel identity is produced by using signal analysis to extract the characteristic signal sequences from the received detection signals, which are related to the transmitted radar signal(s) from the vessel(s).

A method to automatically and continuously provide surveillance based on central and/or distributed surveillance of presence, positions, movements and movement pattern of one or more vessels in narrow waters, a sailing lane or where danger of collision with other vessels or other fixed or floating objects may occur. A vessel emits a sweeping signal that repeatedly hits one or more detectors, which detect the character of the sweeping signal and the time intervals between the signal hits on the respective detector. The exact position of the vessel and/or movements is calculated at least on the basis of trigonometric principles, and the vessel identity is produced by using signal analysis to extract the characteristic signal sequences from the received detection signals, which are related to the transmitted radar signal(s) from the vessel(s).

A data collection device carried on board a satellite and making it possible to localize a source of interference, without using neighboring satellites, comprises: a reception device able to receive the frequency on the ground of the interference; at least three antenna points arranged on the satellite so as to be able to receive a radiofrequency signal coming from the target surface; a processor able to determine the amplitude of the interference signal at the level of each of the antenna points; a connection device able to connect successively each of the antenna points to the processor.