Abstract:
Methods and systems are provided for allowing possible motion or lack of motion of a mobile terminal to be detected based, at least in part, on at least one wireless signal. For example, according to one method a mobile terminal may be configured to operate in a first wireless communication system and the method may include detecting motion or lack of motion of the mobile terminal based, at least in part, on at least one wireless signal from at least one terrestrial-based second wireless communication system, and in response to detecting the motion or lack of motion, initiating or stopping at least one process within the mobile terminal.
Abstract:
Position location signaling system, apparatus, and method are disclosed. Position location beacons can each be configured to transmit a frequency interlaced subset of orthogonal frequencies spanning substantially an entire channel bandwidth. The orthogonal frequencies can be pseudorandomly or uniformly spaced, and each beacon can be allocated an equal number of orthogonal frequencies. Adjacent beacons are assigned mutually exclusive subsets of frequencies can be modulated with an element of a predetermined data sequence. A mobile device can receive one or more of the beacon signals and determine a position using a position location algorithm that determines position in part on an arrival time of the beacon signal. Where the mobile device can receive three or more beacon signals, the mobile device can perform position location by trilateration to the beacon positions based, for example, on a time difference of arrival.
Abstract:
Method and apparatuses for receiving and tracking satellite signals in a highly sensitive and accurate receiver. In one aspect of the invention an exemplary method includes generating a set of at least three indicators based on processing a portion of a satellite positioning system signal received by a receiver and computing a measurement of a parameter from an interpolation of the set of indicators. Each of the indicators corresponds to a different predetermined hypothesized value of the parameter and is indicative of a probability, or likelihood, that the parameter of the signal is equal to that corresponding value.
Abstract:
A method and apparatus are disclosed for fixing the location of a receiver using transmitted signals that include a unique periodically repeating sequence. The apparatus and method are useful in communication systems, especially unsynchronized systems, such as A-GPS utilized on GSM and UMTS cellular telephone systems. A received signal is stored by the receiver for at least two repetitions of the periodically repeating sequence. FFT operations are performed, and the resulting data frequency samples are pruned responsive to a hypothesized residual frequency. This reduces the number of subsequent calculations required and the processing time. A correlation series is determined from the pruned samples and reference frequency samples corresponding to a hypothesized transmitter. If a match is found, a code phase offset is determined; if not, the process is repeated with another hypothesized residual frequency. Multiple correlation series similarly obtained may also be incoherently combined prior to this examination.
Abstract:
A method and apparatus for providing emergency notification by a wireless mobile device in response to triggering a sensor that is remote from the mobile device. A detection system, which may be located within a vehicle, comprises one or more sensors configured to sense an emergency event and transmit a message via a wireless link regarding the emergency event. A wireless mobile device within short range of the transmitter receives the message via a short range receiver located therein and processes the message regarding the triggering of the sensor. For example, the wireless mobile device may be programmed to determine position information about the wireless transmitter and/or mobile device, call a predetermined emergency number such as E911, and transmit data including position and other information from the mobile device to the emergency number in response to the received message.
Abstract:
Method and apparatuses for receiving and tracking satellite signals in a highly sensitive and accurate receiver. In one aspect of the invention an exemplary method includes generating a set of at least three indicators based on processing a portion of a satellite positioning system signal received by a receiver and computing a measurement of a parameter from an interpolation of the set of indicators. Each of the indicators corresponds to a different predetermined hypothesized value of the parameter and is indicative of a probability, or likelihood, that the parameter of the signal is equal to that corresponding value.
Abstract:
To provide accurate and quick position measurements in a practical mobile position location system, the GPS receiver is calibrated, a frequency error in the next time period is predicted using a first frequency locked to an externally transmitted signal, and a second frequency is generated by a GPS oscillator. To predict the error in the next time period, several measurements are made over time, error estimations are made, an error function is approximated responsive to the set of error estimations. This predicted error is then used to correct the GPS receiver in the next time period. In one implementation, a multiple function portable device is disclosed for providing cellular communication using a network of cellular stations that operate at predefined ideal cellular frequencies, and also for providing position location using GPS satellites that transmit GPS signals at a predefined GPS frequency.