Abstract: A security system comprises a secured asset associated with a high-sensitivity GPS receiver that can receive network aiding information. Indoors, the pseudo-ranges from orbiting GPS satellites can be computed by using digital correlators to pull directly received satellite signal transmissions from the noise floor, but the NAV-data transmissions cannot be demodulated well enough due to the attenuation caused by the building structure. So a wireless network is relied upon to provide aiding information that supplies the almanac and ephemeredes. The fact that the NAV-data transmissions cannot be demodulated well enough is taken as indicia that the system is being operated indoors, and such can be used in a geo-fence control to decide if indoor or outdoor use is not permitted. The secured asset can be temporarily or permanently disabled according to such geo-fence controls.

Abstract: In a communications device operating with a blind signal separation (BSS) processor, an initial mixing matrix is formed based upon the different summations of the source signals received by the antenna array. The initial mixing matrix is evaluated to determine a minimum rank that is necessary for at least one source signal to be useable after having been separated from the initial mixing matrix and decoded. An additional mixing matrix is then formed, and also includes the different summations of the source signals. If the rank of the additional mixing matrix is less than the minimum rank associated with the initial mixing matrix, then the source signals are modified so that the rank of the additional mixing matrix is increased.

Abstract: The time difference of arrival for a signal received at two or more receiving sites as transmitted from a wireless communications device, is determined by a frequency domain technique. The constituent frequencies of the signals received at the two or more receiving sites are determined, including the phase, or a value representative of the phase, of each frequency component. The phase values for the same frequency are subtracted to yield a phase difference values as a function of frequency. The slope of the function represents the time difference of arrival for the wireless communications device signal as received at the two receiving sites. To determine the mobile location based on the determined time difference of arrival values, a seed or initial location is first assumed for the wireless communications device and the distance difference of arrival (the time difference of arrival multiplied by the speed of light) is calculated.

Abstract: Apparatus, systems, and methods may provide operating system-independent geolocation information. A compact software and/or firmwave environment may be established prior to loading and/or initializing the main operating system. This environment, sometimes known as a pre-boot environment, may determine geolocation information and/or may provide user access to configuration information and methods, even when the operating system is absent or unavailable.

Abstract: A group global positioning system includes a plurality of positioning signal processing devices with a global positioning function and a plurality of radio signal processing devices corresponding to the positioning signal processing devices. With one of the corresponding radio signal processing devices, one of the positioning signal processing devices outputs analog global positioning information to the remaining ones of the positioning signal processing devices which then performs analog-to-digital conversion on the analog global positioning information and recovers digital global positioning information, thus allowing the remaining ones of the positioning signal processing devices to execute the global positioning function and display related information. The present invention discloses a grouping technique for simultaneously displaying on the positioning signal processing devices the digital global positioning information thereof.

Abstract: A handheld GPS jammer locator for locating a GPS jamming signal generated by a jammer. The handheld GPS jammer locator has two modes of operation, a amplitude mode and a difference finding mode. The amplitude measures the strength of an incoming GPS jamming signal and the difference finding mode determines the direction of the incoming jamming signal.

Abstract: A method and apparatus for estimating a lever arm correction between the wide beam antenna and the spot beam antenna in a navigational satellite system is disclosed. A prescribed satellite maneuver is used to increase the accuracy of the predicted satellite attitude in determining the lever arm, and lever arm corrections are provided from a ground segment to navigation receivers using curve fit coefficients to permit long range estimates and to minimize data transmission requirements.

Abstract: A portable emergency communication device includes a first receiver for receiving location determination signals from the global positioning satellite (GPS) system, and a second receiver for receiving incoming signals from a subscriber-based satellite radio system, such as the Sirius or XM satellite radio service providers. The device includes a transmitter for transmitting outgoing signals to a search and rescue satellite system, such as the Cospas-Sarsat satellite system. The incoming signals are encoded with preprogrammed queries and prompts that are displayed on a display device on the emergency communication device. The outgoing signals are encoded with location coordinates of the device and preprogrammed messages that respond to queries encoded in the incoming signals.

Abstract: Multipath signals (rays) emanating from an object of interest are processed to locate the object. Multipath signals may be accepted, screened, and associated with a specific object by an observer. Information (time, amplitude, and angle information) may be recorded for each ray. A set of incoming rays associated with a signal from an object are traced back toward the emanating object generating traceback ray segments. Candidate crossings of ray traceback segments are tested for time and/or amplitude consistency with ray information, and candidate crossings with inconsistent amplitude and/or time information may be eliminated from consideration. If there is only one candidate crossing remaining, it may be used to define the object location. Otherwise, the remaining crossings may be grouped, each grouping with a crossing cardinality, and location. Multiple crossings of multiple rays may be grouped into clusters with a cluster cardinality and diameter.

Abstract: A smart antenna calibration system is disclosed for calibrating an antenna array having a plurality of antennas. Each antenna has a calibration coupler for providing a monitoring signal indicative of a signal passing through a transceiver associated thereof, and a processing unit including at least one signal splitter that splits at least one monitoring signal and a combiner array comprising one or more combiners for combining at least two split monitoring signals from first and second antennas to produce a first combined signal representing an in-phase sum and a second combined signal representing a quadrature sum. A power detector is in communication with the processing unit, which is configured to estimate a power level of the signal passing each of the first and second antennas and the in-phase power and quadrature power of the in-phase and quadrature sums for determining a phase difference of the signal on the antennas.

Abstract: A beam steering apparatus including an antenna array having a plurality of antenna elements. The antenna elements are spatially arranged with respect to one another and being operable to receive signals. A plurality of optical modulators, each of which is associated with a different one of the antenna elements and are operable to modulate signals received thereby onto a different respective optical carrier. A plurality of delay units for applying an amount of delay to modulated optical signals passing therethrough in respect of one or more of the antenna elements. A demultiplexer for separating the modulated optical carriers within an optical signal output by the delay units. A demodulator for demodulating the signal received by each antenna element from the respective separated modulated optical carrier. A combiner for combining the demodulated received signals output by the demodulator.

Abstract: There is disclosed a method of determining a code phase search window for use by a satellite positioning system receiver associated with a mobile terminal of a communications network when acquiring a signal from a satellite of a satellite positioning system.

Abstract: A model construction module (MCM) for constructing a probabilistic model (PM) of a wireless environment (RN) in which a target device (T) communicates using signals that have a measurable signal value (x), such as signal strength. The model construction module forms several submodels (611–631) of the wireless environment (RN). Each submodel indicates a probability distribution (F1–F3) for signal values at one or more locations (Q1–QY) in the wireless environment. The module combines the submodels to a probabilistic model (PM) of the wireless environment (RN), such that the probabilistic model indicates a probability distribution for signal values at several locations in the wireless environment. Alternatively, the model may insert new locations to a single model based on a combination of existing locations. The combination of submodels or existing locations includes combining the inverse cumulative distribution functions of the submodels or existing locations.

Abstract: A GPS receiver is disclosed which has an omnidirectional antenna and a directional antenna and is configured to (i) acquire a first GPS signal from the output of the directional antenna, either alone or combined with the output of the omnidirectional antenna, and (ii) acquire a second GPS signal from the output of the omnidirectional antenna alone. Also, disclosed is a GPS receiver having an omnidirectional antenna and a directional antenna which is configured to acquire a GPS signal from the output of the directional antenna alone.

Abstract: A receiver in receipt of a plurality of pseudo noise codes, where each of the pseudo noise codes originates from a GPS transmitter and a plurality of chips make tip each pseudo noise code with an offset between 511 chips before a pseudo noise code boundary and 512 chips after the pseudo noise code boundary, and a local clock having an error of less than 0.5 ms relative to a GPS time and synchronized to a GPS signal that is able to be decoded with a decoder connected to the receiver and the local clock and by simultaneously solving the four pseudo range equations for at least four GPS transmitters a determination of the location of the receiver occurs.

Abstract: A communications device for separating source signals provided by M signal sources includes an antenna array comprising N elements for forming at least N antenna beams for receiving at least N different summations of the M source signals, with N and M being greater than 2. A controller is connected to the antenna array for selectively forming the at least N antenna beams. A blind signal separation processor forms a mixing matrix comprising up to the at least N different summations of the M source signals. The blind signal separation processor also determines if the different summations of the M source signals are correlated or statistically independent, and if not, then cooperates with the controller for forming different beams for receiving new different summations of the M source signals to replace the different summations of the M source signals that are not correlated or statistically independent in the mixing matrix.

Abstract: A positioning satellite for a constellation of satellites of a radio navigation satellite system includes transmitter adapted to transmit operational signals intended to enable the determination of positions of radio navigation receivers, receiver adapted to receive at least some of the operational signals transmitted by positioning satellites of the constellation that are in view and processor adapted to interrupt transmission of the operational signals by the transmitter at selected times for a selected duration and to analyze during each transmission interruption at least some of the operational signals received by the receiver during at least a portion of the selected duration, for example to verify the waveform thereof and/or to determine pseudodistances.

Abstract: A substrate is provided with a multiplicity of electrically conductive elements, and the elements are interconnected to form an antenna structure for desired application. Either the antenna pattern itself may be altered according to the invention, or one or more feed points may be changed, or all of the above. As such, the electrically conductive elements may be interconnected to change the directionality of the antenna pattern, the gain, the frequency response, or other operational characteristics. The electrically conductive elements may be arranged in the form of an inchoate antenna pattern or regular array. Switches at key points of the structure enable the pattern to be changed dynamically. Such switching may be carried out in real time in accordance with transmissions/reception characteristics, or in advance using simulations associated with the switched elements.

Abstract: Methods and apparatus for improving the effective resolving power of an array antenna are described that are not limited by the physical characteristics of the array. In an array with M elements, up to M?1 directional vectors may be selected, preferably at angles corresponding to the main lobe and/or side lobes of an array antenna beam pattern. A received signal plus interference (s+i) is zero-transformed to eliminate interference received from the plurality of selected directions. The zero-transformed s+i is then restored to obtain the signal of interest observed at maximum gain undisturbed by interference incident from arbitrarily close signal sources. The approach may be combined with conventional beamforming techniques to remove interference incident from angles corresponding to the side lobes, where conventional beamforming techniques are most effective.

Abstract: A satellite navigation method determined the position of the receiver (1) by determining the signal travel time between the satellites (3, 4) and the receiver (1). Either the times of reception by the receiver (1) of the signals from the satellites are determined, both by means of an accurate time reference, in the receiver (1), and based on the signals from the satellites, then compared with each other, or at least two position solutions are determined based on the reception times, by the receiver (1) of signals from the satellites, determined by means of an accurate time reference of the receiver (1) and of at least one signal from the different satellites respectively, then compared with each other.