摘要:
A method and system for assisting mobile stations to locate a satellite use an efficient messaging format. A server computes a correction between coarse orbit data of a satellite and precise orbit data of the satellite. A coordinate system is chosen such that variation of the correction is substantially smooth over time. The server further approximates the correction with mathematical functions to reduce the number of bits necessary for transmission to a mobile station. The mobile station, upon receiving the coefficients, evaluates the mathematical functions using the coefficients and a time of applicability (e.g., the current time), converts the evaluated result to a standard coordinate system, and applies the conversion result to the coarse orbit data to obtain the precise orbit data.
摘要:
A method and system for assisting mobile stations to locate a satellite use an efficient messaging format. A server computes a correction between coarse orbit data of a satellite and precise orbit data of the satellite. A coordinate system is chosen such that variation of the correction is substantially smooth over time. The server further approximates the correction with mathematical functions to reduce the number of bits necessary for transmission to a mobile station. The mobile station, upon receiving the coefficients, evaluates the mathematical functions using the coefficients and a time of applicability (e.g., the current time), converts the evaluated result to a standard coordinate system, and applies the conversion result to the coarse orbit data to obtain the precise orbit data.
摘要:
A method and system for assisting mobile stations to locate a satellite use an efficient messaging format. A server computes a correction between coarse orbit data of a satellite and precise orbit data of the satellite. A coordinate system is chosen such that variation of the correction is substantially smooth over time. The server further approximates the correction with mathematical functions to reduce the number of bits necessary for transmission to a mobile station. The mobile station, upon receiving the coefficients, evaluates the mathematical functions using the coefficients and a time of applicability (e.g., the current time), converts the evaluated result to a standard coordinate system, and applies the conversion result to the coarse orbit data to obtain the precise orbit data.
摘要:
A method and system for assisting mobile stations to locate a satellite use an efficient messaging format. A server computes a correction between coarse orbit data of a satellite and precise orbit data of the satellite. A coordinate system is chosen such that variation of the correction is substantially smooth over time. The server further approximates the correction with mathematical functions to reduce the number of bits necessary for transmission to a mobile station. The mobile station, upon receiving the coefficients, evaluates the mathematical functions using the coefficients and a time of applicability (e.g., the current time), converts the evaluated result to a standard coordinate system, and applies the conversion result to the coarse orbit data to obtain the precise orbit data.
摘要:
A method and system for assisting mobile stations to locate a satellite use an efficient messaging format. A server computes a correction between coarse orbit data of a satellite and precise orbit data of the satellite. A coordinate system is chosen such that variation of the correction is substantially smooth over time. The server further approximates the correction with mathematical functions to reduce the number of bits necessary for transmission to a mobile station. The mobile station, upon receiving the coefficients, evaluates the mathematical functions using the coefficients and a time of applicability (e.g., the current time), converts the evaluated result to a standard coordinate system, and applies the conversion result to the coarse orbit data to obtain the precise orbit data.
摘要:
A method and system for assisting mobile stations to locate a satellite use an efficient messaging format. A server computes a correction between coarse orbit data of a satellite and precise orbit data of the satellite. A coordinate system is chosen such that variation of the correction is substantially smooth over time. The server further approximates the correction with mathematical functions to reduce the number of bits necessary for transmission to a mobile station. The mobile station, upon receiving the coefficients, evaluates the mathematical functions using the coefficients and a time of applicability (e.g., the current time), converts the evaluated result to a standard coordinate system, and applies the conversion result to the coarse orbit data to obtain the precise orbit data.
摘要:
A method and system for assisting mobile stations to locate a satellite use an efficient messaging format. A server computes a correction between coarse orbit data of a satellite and precise orbit data of the satellite. A coordinate system is chosen such that variation of the correction is substantially smooth over time. The server further approximates the correction with mathematical functions to reduce the number of bits necessary for transmission to a mobile station. The mobile station, upon receiving the coefficients, evaluates the mathematical functions using the coefficients and a time of applicability (e.g., the current time), converts the evaluated result to a standard coordinate system, and applies the conversion result to the coarse orbit data to obtain the precise orbit data.
摘要:
An apparatus and method for detecting whether a mobile device is in flight based on sensor measurements from a 3-dimensional accelerometer are presented. For example, embodiments estimate a direction of gravity and non-gravity acceleration, separate this non-gravity acceleration into a vertical and horizontal components, then test the estimated accelerations to determine whether the mobile device is experiencing sufficient vertical acceleration to warrant an in-flight determination.
摘要:
Systems and methods are described for measuring orientation of sensors associated with a mobile device with respect to pedestrian motion of a user of the mobile device. An example technique described herein includes obtaining acceleration information associated with the mobile device, partitioning the acceleration information according to respective detected pedestrian steps of the user, identifying a forward motion direction of the user of the mobile device based on the acceleration information and the detected pedestrian steps, and computing a misalignment angle between the forward motion direction of the user of the mobile device and an orientation of the mobile device.
摘要:
A method and device for combating cross-correlation false alarms by introducing code diversity in the correlation process in which the search code may be diversified by the use of code staggering and/or code scrambling. The energy levels of the signals before and after the search code have been diversified may be evaluated to detect a false alarm. In addition, a set of parameterized analytical models may be used to estimate the rate of false alarms from cross-correlation in wireless networks in order to guide development and design of wireless transceivers.