Abstract: The invention provides a method of adjusting a principal communication direction of a steerable directional antenna for communicating with a terrestrial electromagnetic signal source, the method comprising: providing location specific steering data comprising one or more steering data portions, each of the steering data portions being specific to a respective location; determining a location of the steerable directional antenna; selecting a steering data portion from the location specific steering data taking into account the determined location of the antenna; determining an adjusted principal communication direction of the steerable directional antenna taking into account the said selected steering data portion; and adjusting the principal communication direction of the steerable directional antenna in accordance with the said adjusted principal communication direction.

Abstract: The invention provides a method of adjusting a principal communication direction of a steerable directional antenna for communicating with a terrestrial electromagnetic signal source, the method comprising: providing location specific steering data comprising one or more steering data portions, each of the steering data portions being specific to a respective location; determining a location of the steerable directional antenna; selecting a steering data portion from the location specific steering data taking into account the determined location of the antenna; determining an adjusted principal communication direction of the steerable directional antenna taking into account the said selected steering data portion; and adjusting the principal communication direction of the steerable directional antenna in accordance with the said adjusted principal communication direction.

Abstract: The invention provides impedance matching circuitry for adjusting an impedance match between a source impedance (2) and a load impedance (4), the impedance matching circuitry comprising: tapered transmission line circuitry which comprises one or more tapered transmission lines (10) coupled or couplable between the source impedance and the load impedance; and a controller (20) in communication with the tapered transmission line circuitry and configured to adjust one or more impedances of the tapered transmission line circuitry to thereby adjust an impedance match between the source impedance and the load impedance.

Abstract: A method of estimating the position of a user device is provided. The user device is initially in electronic communication with a positioning system controller through a communication network. The method comprises determining that a user device meets one or more proximity criteria with respect to an offline region where electronic communication between the user device and the positioning system controller, through the communication network, is expected to meet one or more failure criteria. Responsive thereto and in advance of the user device entering the said offline region, the positioning system controller transmitting local positioning data to the user device, the local positioning data comprising data concerning electromagnetic signal sources in the said offline region. The user device subsequently estimates its position whilst it is within the offline region by measuring signal data from a plurality of electromagnetic signal sources and processing the measured signal data and the local positioning data.

Abstract: The invention provides a method of estimating the position of a device, the method comprising: providing a database of location specific geographical descriptive data; obtaining location data relating to the position of the device; retrieving geographical descriptive data specific to an indoor region from the said database, the indoor region being selected dependent on the location data; and subsequently estimating the position of the device taking into account the retrieved data. The method can be used with existing or new positioning systems to improve the execution of the said positioning systems, particularly when the positioning system is being used indoors.

Abstract: A method of estimating the position of a user device is provided. The user device is initially in electronic communication with a positioning system controller through a communication network. The method comprises determining that a user device meets one or more proximity criteria with respect to an offline region where electronic communication between the user device and the positioning system controller, through the communication network, is expected to meet one or more failure criteria. Responsive thereto and in advance of the user device entering the said offline region, the positioning system controller transmitting local positioning data to the user device, the local positioning data comprising data concerning electromagnetic signal sources in the said offline region. The user device subsequently estimates its position while it is within the offline region by measuring signal data from a plurality of electromagnetic signal sources and processing the measured signal data and the local positioning data.

Abstract: An antenna element (100) comprises an active patch formed by a conductive layer (104) on a front surface of a substrate (102) and a parasitic ground patch (106) on a back surface of the substrate. The active patch has a spiral slot (112) in a central portion, and peripheral portions (110a-110d) which are substantially wider than the spiral slot. A signal feed strip (114) extends from a side of said active patch across the front surface of the substrate. Two signal ground strips (116, 118) are provided on the front surface, each separated from the active patch by a predetermined gap (120, 122). The parasitic ground patch has a slot in a central portion substantially back-to-back with the central portion of the active patch through the substrate. The element has broadband properties that can be tuned by various modifications. Several elements can be used in close array, with lower cross-talk than known antenna designs.

Abstract: The invention provides a method of estimating the position of a device, the method comprising: providing a database of location specific geographical descriptive data; obtaining location data relating to the position of the device; retrieving geographical descriptive data specific to an indoor region from the said database, the indoor region being selected dependent on the location data; and subsequently estimating the position of the device taking into account the retrieved data. The method can be used with existing or new positioning systems to improve the execution of the said positioning systems, particularly when the positioning system is being used indoors.

Abstract: There is disclosed a method of updating a database of spatial features, said spatial features being associated with a region, and the method comprising: receiving positioning data that has been collected at a plurality of locations within the region; processing the collected positioning data to identify at least one candidate spatial feature associated with the region; identifying at least one other spatial feature corresponding to said at least one candidate spatial feature, said at least one other spatial feature and said at least one candidate spatial feature as a whole constituting matching spatial features; processing said matching spatial features; and updating the database of spatial features in dependence on the processing of said matching spatial features.

Abstract: There is disclosed a method of updating a database of positioning data, using a mobile user device moved along a path through a plurality of positions, the method comprising the steps of: at each of the plurality of positions: receiving position estimate data and measurement data from a plurality of positioning modules associated with the mobile user device; calculating an estimate of the position in dependence on the data received from the plurality of positioning modules; and storing the estimate of the position and the measurement data; subsequently processing the stored measurement data to calculate at least one revised estimate of a respective position; and processing said at least one revised estimate to update the database of positioning data.

Abstract: In a mobile positioning system, mobile user devices carry out data validation on locally stored positioning data, regulating the positioning data provided to a positioning module and selectively requesting updated positioning data from a central database. A controller receives requests for updated positioning data and selectively responds with updates. The mobile user devices store observations data concerning measurements of signals from electromagnetic signal sources and transmit data about the locally stored observations data to the controller. The controller then selectively requests transmission of the locally stored observations data and the mobile user device determines when and whether to transmit that data. The amount of positioning data which must be transmitted to and from the mobile user device and the overall power consumption of the mobile user device is reduced.

Abstract: The invention provides a method of estimating the position of a user device carried by a user, the method comprising: providing an initial position of the user device; measuring a vertical acceleration of the user device, thereby generating vertical acceleration data; measuring an orientation of the user device, thereby generating principal direction data; processing the vertical acceleration data to detect one or more steps taken by the user, and subsequently validating the detection of one or more of said one or more steps; generating one or more motion vectors in respect of the validated steps taken by the user using the principal direction data; and estimating an updated position of the user device by combining the motion vector(s) with the initial position. The method may be used by, for example, a smartphone to estimate its position, particularly where other positioning systems are unavailable.

Abstract: Disclosed is the estimation of the position of a user device (18) using radio beacons (B1-B4) which are operable at a plurality of transmit power levels. The radio beacons (B1-B4) may transmit their position and current transmit power level. Estimates of distance between a user device and a radio beacon can take into account both received signal strength and the current transmit power level of the radio beacon. The position of the user device (18) can be estimated taking into account whether a radio beacon (B1-B4)) can be detected at a given transmit power level. The transmit power level of the radio beacon may vary according to a cycle. The transmit power level of the radio beacon may be changed to facilitate positioning, for example in response to a signal from a user device. A radio beacon (B1-B4) changes transmit power level in a cycle. The radio beacon can reduce transmit power level responsive to a signal.

Abstract: There is disclosed a method of estimating the location of a plurality of electromagnetic signal sources, comprising: scanning at a first plurality of locations to generate signal source position data, the signal source position data representing estimates of the position of at least one of said signal sources; scanning at a second plurality of locations using a signal detection system to generate signal detection data, the signal detection data relating to signals received at the second plurality of locations from the signal sources; processing the signal source position data in dependence on the signal detection data to correct estimation errors in the signal source position data; and outputting the processed signal source position data.

Abstract: Disclosed is the estimation of the position of a user device using radio beacons which are operable at a plurality of transmit power levels. The radio beacons may transmit their position and current transmit power level. Estimates of distance between a user device and a radio beacon can take into account both received signal strength and the current transmit power level of the radio beacon. The position of the user device can be estimated taking into account whether a radio beacon can be detected at a given transmit power level. The transmit power level of the radio beacon may vary according to a cycle. The transmit power level of the radio beacon may be changed to facilitate positioning, for example in response to a signal from a user device. A radio beacon changes transmit power level in a cycle. The radio beacon can reduce transmit power level responsive to a signal. The radio beacon may be compatible with Bluetooth short range wireless connectivity standard core specification version 4.0.

Abstract: There is disclosed a method of managing a database of positioning data, the positioning data including electromagnetic signal source data for use by a positioning system, and the method comprising: receiving signal data relating to signals received from a plurality of electromagnetic signal sources; associating an appropriate one of a plurality of zone identifiers with each of the electromagnetic signal sources, each zone identifier being associated with a respective geographical zone; selecting a subset of the plurality of electromagnetic signal sources in dependence on their associated zone identifiers; processing the signal data relating to the subset of the plurality of electromagnetic signal sources to compute position estimates of the electromagnetic signal sources; and updating the database of electromagnetic signal source data in dependence on the computed position estimates.

Abstract: There is disclosed a method of managing a database of positioning data, the positioning data including electromagnetic signal source data for use by a positioning system, and the method comprising: receiving signal data relating to signals received from a plurality of electromagnetic signal sources; associating an appropriate one of a plurality of zone identifiers with each of the electromagnetic signal sources, each zone identifier being associated with a respective geographical zone; selecting a subset of the plurality of electromagnetic signal sources in dependence on their associated zone identifiers; processing the signal data relating to the subset of the plurality of electromagnetic signal sources to compute position estimates of the electromagnetic signal sources; and updating the database of electromagnetic signal source data in dependence on the computed position estimates.

Abstract: There is disclosed a method of estimating the location of a plurality of electromagnetic signal sources, comprising: scanning at a first plurality of locations to generate signal source position data, the signal source position data representing estimates of the position of at least one of said signal sources; scanning at a second plurality of locations using a signal detection system to generate signal detection data, the signal detection data relating to signals received at the second plurality of locations from the signal sources; processing the signal source position data in dependence on the signal detection data to correct estimation errors in the signal source position data; and outputting the processed signal source position data.

Abstract: There is disclosed a method of estimating the position of a user device (902), the method comprising: receiving signal data from a plurality of electromagnetic signal sources (W) having known locations; dividing the plurality of electromagnetic signal sources (W) into a plurality of groups (G1, G2, G3, G4, G5) of the signal sources; processing the received signal data to generate group position data representing the position of at least one group location (910, 912, 914, 916, 918), each group location being characteristic of the location of a respective group of the signal sources; and processing the group position data to generate position data representing an estimate of the position of the user device (902); and outputting the position data.

Abstract: Data concerning the strength of signals received from electromagnetic signal sources within a building is obtained at a plurality of points. Instead of storing the raw data for use in positioning, the data for each electromagnetic signal source is fitted to a function of received signal strength with distance from the electromagnetic signal source. This data is then used to estimate the position of a user device. The advantage of the invention is that the amount of data which requires to be stored is significantly reduced.