Abstract:
PROBLEM TO BE SOLVED: To provide a system and a method for acquiring signal acquisition auxiliary data.SOLUTION: The signal acquisition auxiliary data is acquired for a receiving device like a radio location place-supported position determination device which retrieves a signal from an arbitrary source like a satellite body and a base station. The data can be acquired from data acquired before based upon evaluation of change in parameter like time and position which possibly exerts a bad influence on validity. In some case, the data can be adjusted for the change in parameter. When acquisition auxiliary data provided by, especially, a remote entity includes a more distinct parameter than a generally provided one, data which is made more accurate can be calculated by a receiver using a partial measured value of a signal set. As long as a movement of a mobile station which cannot be corrected is detected and validity of previous data is kept, new data need not be acquired until the validity of the previous data expires because of a limit of extrapolation of time using a Doppler coefficient.
Abstract:
PROBLEM TO BE SOLVED: To provide methods and apparatus that may be used in identifying a location of a signal (such as a GPS signal) in a two-dimensional search space. SOLUTION: A method according to one embodiment includes obtaining a plurality of results by correlating a received code with a reference code. Each of the results corresponds to one of a plurality of code phase hypotheses and one of a plurality of frequency hypotheses. For each of the plurality of frequency hypotheses, a plurality of peaks are selected from among the results for the frequency hypotheses and a list on which the plurality of peaks selected are ordered is stored. COPYRIGHT: (C)2011,JPO&INPIT
Abstract:
PROBLEM TO BE SOLVED: To provide a procedure for estimating a parameter of a local maximum or minimum of a function. SOLUTION: In a method of and system for estimating a parameter of a local maximum or minimum of a correlation function derived from a received signal, an interpolated local maximum or minimum is determined. An interpolation offset is then derived, including a deviation between a position of the interpolated local maximum or minimum of the function and a position of a sampled local maximum or minimum of the function. An estimated value of the parameter is derived from the interpolation offset. COPYRIGHT: (C)2011,JPO&INPIT
Abstract:
PROBLEM TO BE SOLVED: To prevent an improper signal from being discriminated erroneously as a measured value for position determination of a moving station. SOLUTION: Before determining a plurality of measured values for position determination of a moving station from a position determination signal received by the moving station, and determining consistency between the plurality of measured values, in order to generate a plurality of probability estimations, each probability in which each of the plurality of measured values is an erroneous alarm is estimated. The position of the moving station is determined by using the measured values. Then, it is determined whether the determined position is acceptable or not, by using an estimated erroneous alarm probability indicator. COPYRIGHT: (C)2011,JPO&INPIT
Abstract:
PROBLEM TO BE SOLVED: To prevent an improper signal from being discriminated erroneously as a measured value for position determination of a moving station. SOLUTION: A plurality of measured values for position determination of a moving station are determined from a position determination signal received by the moving station, and before determining consistency between the plurality of measured values, a probability that each of the plurality of measured values is an erroneous alarm is estimated in order to generate estimation of a plurality of probabilities. The position of the moving station is determined by using the measured values. Then, it is determined whether the determined position can be accepted or not, by using the estimated erroneous alarm probability indicator. COPYRIGHT: (C)2011,JPO&INPIT
Abstract:
PROBLEM TO BE SOLVED: To provide a method and apparatus for reducing code phase search space of a GPS receiver of a client.SOLUTION: The communication system includes a transmitter for transmitting timing information from a server to a client to help the client locate a first satellite, and a receiver for using timing differences between satellites to synchronize and locate other satellites. Phase hypotheses must be calculated to establish communication between the server and the client, and therefore the number of phase hypotheses is reduced.
Abstract:
PROBLEM TO BE SOLVED: To reduce or eliminate redundant and superfluous data, and further, ensure that wireless devices are not loaded with additional capacity, and that the wireless devices are provided with precise position information.SOLUTION: An assisted wireless position determination system comprises a plurality of base stations and a plurality of wireless devices, such as mobile telephones and personal digital assistants, adapted to communicate with the base stations. The assisted wireless position determination system also comprises a position determination system for determining geographic positions of the wireless devices. The position determination system comprises a position determination entity (PDE) which is connected to the base stations and serves as a processing server for computing the positions of the wireless devices.
Abstract:
PROBLEM TO BE SOLVED: To allow a GPS receiver to receive an effective signal under a jammer environment.SOLUTION: A plurality of results are obtained by correlating a received code with a reference signal. A list of peaks of each of a plurality of frequency hypotheses is obtained. Each peak has an energy result and corresponds to a code phase hypothesis. A maximum peak is selected from among the peaks of the plurality of frequency hypotheses.
Abstract:
PROBLEM TO BE SOLVED: To provide a system and method to obtain signal acquisition assistance data.SOLUTION: Signal acquisition assistance data is obtained for receiving devices such as wireless position assisted location decision devices seeking signals from any source, such as satellite vehicles and base stations. The data may be obtained from previously acquired data, based upon evaluation of changes in parameters such as time and location that may jeopardize validity. In some cases, the data may be adjusted for the changes in parameters. Refined data may be calculated by a receiver using partial measurements of signal sets, particularly if the acquisition assistance data provided by a remote entity includes more distinct parameters than those which have typically been provided. New data need not be obtained until the validity of previous data expires due to limitations upon temporal extrapolation using Doppler coefficients, unless mobile station movement that cannot be compensated is detected, and jeopardizes validity of the previous data.
Abstract:
PROBLEM TO BE SOLVED: To provide systems, methods and apparatus for frequency control.SOLUTION: A receiver according to one embodiment includes a frequency control unit configured to receive a stream of samples including a plurality of received instances of a transmitted signal. The frequency control unit is configured to output a first correction signal (e.g. indicating a rotation) that is based on more than one of the received instances and a second correction signal (e.g. to control an oscillator) that is also based on more than one of the received instances. In some embodiments, a controlled oscillator is used to receive and/or transmit another signal, such as a signal received from a GPS space vehicle. In other embodiments, the received instances are from a GPS signal. In further embodiments, a fixed-frequency oscillator is used, and the second correction signal is used to receive and/or transmit another signal, such as a GPS signal.