Abstract: A method for identifying transmitters by a terminal in a single-frequency network comprising a plurality of transmitters. The transmitters are synchronized and transmit with an artificial delay ?i, specific to each transmitter. The method comprises at least one step of acquiring the approximate position of the terminal {circumflex over (p)}, the position pi of a list of transmitters {Tx} in the vicinity of the terminal and the delays ?i associated with them, a step of measuring pseudo-distances ?i between the transmitters and the terminal and a step of associating the measurements ?i with the transmitters of known positions pi by minimizing a cost function, said cost function ?(?i,{circumflex over (p)},?) corresponding to the norm of the error between the measurements ?i and a model of measurements of the pseudo-distances applied to a permutation of the position of the transmitters ?.

Abstract: A radiometric imaging device and a corresponding method for scanning a scene. The device comprises a radiometer configured to detect radiation in a predetermined spectral range emitted from said scene and to generate a radiation signal from said detected radiation, and a processor configured to process said generated radiation signal by de-convoluting said generated radiation signal by use of a distance-dependent de-blur kernel, which is determined depending on the distance between said scene and the radiometer.

Abstract: A mechanism for mitigating inter-user interference in a multi-user wireless communication environment is disclosed. A first network device determines a plurality of steering matrices, associated with a corresponding plurality of subcarriers, for each of at least a subset of destination devices associated with the first network device. A phase difference between corresponding steering vectors of each pair of consecutive steering matrices of the plurality of steering matrices associated with each of the subset of destination devices is determined and phase rotation is performed to maintain phase continuity between the consecutive steering matrices. One or more pre-coding matrices are calculated based on at least a subset of the plurality of steering matrices associated with the subset of destination devices. The one or more pre-coding matrices are applied to data to be transmitted to the subset of destination devices to mitigate interference between each of the subset of destination devices.

Abstract: A method and apparatus for estimating and compensating for a broad class of non-Gaussian sensor and process noise. In one example, a coded filter combines a dynamic state estimator (for example, a Kalman filter) and a non-linear estimator to provide approximations of the non-Gaussian process and sensor noise associated with a dynamic system. These approximations are used by the dynamic state estimator to correct sensor measurements or to alter the dynamic model governing evolution of the system state. Examples of coded filters leverage compressive sensing techniques in combination with error models based on concepts of compressibility and the application of efficient convex optimization processes.

Abstract: A process for determination of navigation parameters of a carrier by a hybridisation device comprising a bank (3) of Kalman filters, each working out a hybrid navigation solution from inertial measurements calculated by a virtual platform (2) and raw measurements of signals emitted by a constellation of satellites supplied by a satellite-positioning system (GNSS), characterised in that it comprises the steps of: determination for each satellite of at least one probability ratio between a hypothetical breakdown of given type of the satellite and a hypothetical absence of breakdown of the satellite, declaration of a breakdown of given type on a satellite as a function of the probability ratio associated with this breakdown and of a threshold value, estimation of the impact of the breakdown declared on each hybrid navigation solution, and correction of hybrid navigation solutions as a function of the estimation of the impact of the breakdown declared.

Abstract: Systems, methods and devices for improving the performance of Global Navigation Satellite System (GNSS) receivers are disclosed. In particular, the improvement of the ability to calculate a satellite position or a receiver position where a receiver has degraded ability to receive broadcast ephemeris data directly from a GNSS satellite is disclosed. Correction terms can be applied to an approximate long-term satellite position model such as the broadcast almanac.

Abstract: A method for resolving sub-carrier ambiguities of a total number of tracking channels of a binary offset carrier (BOC) navigation signal is provided. For a simultaneously considered subset of at least four tracking channels, a set of sub-carrier candidate ambiguities is determined based on the sub-carrier modulation. Position and receiver clock error are calculated for each possible combination of sub-carrier ambiguities. Predicted delays are calculated based on each calculated position and receiver clock error. Differences between the predicted delays and the delay candidates originating from each specific combination of subcarrier ambiguities are calculated. A residual is calculated based on the differences and the set of sub-carrier ambiguities and the corresponding position and receiver clock error leading to the smallest residual are selected.

Abstract: According to one embodiment of the invention, a method of signal modulation includes modulating a signal by providing respective sets of weights to an active array antenna. Each set of weights specifies the same preferential direction for transmission by the active array antenna, but corresponds to a respective different one of a phase and amplitude of the signal in the preferential direction. The respective ones of a phase in the preferential direction provide modulation of the signal.

Abstract: A method of forming an estimate of the two-dimensional position of a radio receiver relative to a plurality of radio transmitters each having an associated position estimate and a position uncertainty expressible as an uncertainty ellipse having major and minor axes, the method comprising using the uncertainty vectors describing the uncertainty ellipses of the radio transmitters in a predetermined coordinate system to define a new compound coordinate basis, and forming an estimate of the two-dimensional position of the radio receiver in the compound coordinate basis by projecting the major and minor axes of each uncertainty ellipse onto the new compound coordinate basis and calculating the position of the radio receiver by means of a weighted centroid that uses weighting values calculated in the new compound coordinate basis and position estimates of the plurality of the radio transmitters expressed in the compound coordinate basis.

Abstract: Systems and methods are provided for determining position location information in a wireless network. In one embodiment, timing offset information is communicated between multiple transmitters and one or more receivers. Such information enables accurate position or location determinations to be made that account for timing differences throughout the network. In another embodiment, transmitter phase adjustments are made that advance or delay transmissions from the transmitters to account for potential timing differences at receivers. In yet another embodiment, combinations of timing offset communications and/or transmitter phase adjustments can be employed in the wireless network to facilitate position location determinations.

Abstract: A navigation system includes first receiver receiving satellite signals, second receiver receiving differential correction data from ground receivers, and processing device coupled to receivers.

Abstract: In one example, a method includes determining, based on first motion data, that a change in an angle of a mobile computing device relative to gravity satisfies a threshold amount of change, and, responsive to determining that the change in the angle satisfies the threshold amount of change, initiating, at a first position of the mobile computing device, storage of second motion data, wherein the first position is a reference position. The method may also include determining, based on an external signal, a second position of the mobile computing device, wherein the second position is a current position of the mobile computing device that is different from the reference position, and, responsive to determining the second position of the mobile computing device, determining, based on the second motion data and the current position, the reference position of the mobile computing device.

Abstract: An auxiliary positioning method, applied to a portable electronic device operative in a wireless communication network system and a satellite positioning system, for determining current position information of the potable electronic device, includes steps of receiving a plurality of current signals from at least one base station in the wireless communication network system to generate current signal information; accessing at least one track record related to the current signal information from a track record database, wherein the track record database includes a plurality of track records which record respective position information and signal information of base stations corresponding to the position information; and calculating the current position information according to the at least one track record.

Abstract: A method and apparatus for maintaining integrity of long-term-orbit information used by a Global-Navigation-Satellite-System or other positioning receiver is described. The method comprises obtaining a predicted pseudorange from a first set of long-term-orbit information possessed by a positioning receiver; obtaining, at the positioning receiver from at least one satellite, a measured pseudorange; determining validity of the predicted pseudorange as a function of the predicted pseudorange and the measured pseudorange; and excluding from the long-term-orbit information at least a portion thereof when the validity of the predicted pseudorange is deemed invalid. Optionally, the method may comprise updating or otherwise supplementing the long-term-orbit information with other orbit information if the validity of the predicted pseudorange is deemed invalid.

Abstract: A global navigation satellite system configured to operate in a noisy environment receives the same satellite signals in two separate channels. Each channel processes the signals independently according to different filtering constraints; one channel applies narrow filtering constraints while the other channel applies broader filtering constraints. Narrow filtering constraints allow the receiver to acquire a usable signal under certain conditions but not while moving rapidly. Broader filtering constraints allow the receiver to acquire a usable signal during rapid movement, but cannot overcome intense interference. A device implementing both constraint options is usable under a wider range of situations.

Abstract: A method, computer program product, and system are provided for position estimation in a geo-location system. For example, the method can include receiving a plurality of position measurements from a respective plurality of satellites in a global navigation satellite system. From the plurality of position measurements, a position measurement with a maximum pseudo-range residual value can be selected. A position uncertainty estimate can be determined based on the position measurement with the maximum pseudo-range residual value. Further, a position estimation algorithm can receive the position uncertainty estimate as an input, thereby improving position estimation of the geo-location system.

Abstract: The present invention is related to location positioning systems, and more particularly, to a method and apparatus for providing an update of ephemeris information. According to one aspect, GPS enabled devices in the signal unavailable area monitors the state of its ephemeris data and time information. When the ephemeris data and time information become out of date, the GPS enable device uses an ad hoc Bluetooth network to retrieve ephemeris data and time information from another GPS enabled device with more current data. According to further aspects, a map of a deep hole region in which GPS and other cellular signals are not available, is generated to enable power reduction and cost saving measures.

Abstract: A receiver for receiving both GPS signals and GLONASS signals is provided. This receiver includes an analog front end (AFE), a GPS digital front end (DFE) and a GLONASS DFE for receiving an output of the AFE, and a dual mode interface (DMI) for receiving outputs of the GPS and GLONASS DFEs. Search engines are provided for receiving outputs of the DMI. Notably, certain front-end components of the AFE are configured to process both the GPS signals and the GLONASS signals.

Abstract: Embodiments of a system and method for determining an angle-of-arrival (AOA) of signals received from a transmitting device are shown. Signals from the transmitting device are received through two or more pairs of spatially-diverse antennas. A non-inverted version of the signals received through a first antenna of a pair is injected into a first input of a surface-acoustic-wave (SAW) device. An inverted version of the signals received through a second antenna of the pair is injected into a second input of the SAW device. Signals present at tap outputs are processed to determine a time-difference-of-arrival (TDOA) between the signals received through each pair of antennas. The AOA may be calculated from the TDOAs determined from two or more pairs of antennas.

Abstract: A first network device including a calibration module, a steering module, and a control module. The calibration module is configured to determine whether a second network device is capable of generating steering data for the first network device, wherein the steering data corresponds to data for steering signals in a desired direction. The steering module is configured to, if the second network device is not capable of generating the steering data for the first network device, receive channel state information from the second network device and determine the steering data based on the channel state information. The control module is configured to receive the steering data from the second network device if the second network device is capable of generating the steering data for the first network device.