Nokia Mobile Phones Limited

Nokia Corporation

Jari Syrj&auml;rinne

Harri Valio

David Akopian

Kimmo Alanen

Niilo Torsten Sirola

Samuli Pietil&auml;

The invention relates to a method and to devices for determining in a positioning system the time of reception of a beacon signal which was received and tracked by a receiver. In order to enable a re-acquisition of the system time based on a noisy received signal, it is proposed that the method comprises as a first step reconstructing a beacon signal for an interval based on available information. Then, a cross-correlation is performed between the reconstructed signal and the received signal at different relative positions to each other. Next, the time of transmission of the received signal is determined based on information for the reconstructed signal and on the relative position resulting in the maximum correlation value. Finally, a time of reception of said received signal is determined as the sum of the determined time of transmission of the received signal and of a calculated time of flight of the received signal.

Method, receiver and system for determining the time of reception of a beacon signal

A method and apparatus for conserving power in a positioning system receiver using ranging signals to determine a state of motion of the receiver, the method including: a step ( ) of performing at least a predetermined number of solutions of the state of motion of the receiver using a filter solution based on a variable mix of models of the motion of the receiver, and of providing the model mix used in each solution; and a step ( ) of adopting a partial duty cycle indicating a percentage of time selected receiver components are powered on, based on the mix of models used in successive solutions. Typically, the receiver includes a radiofrequency (RF) front end module and a baseband processor module and the selected components that are powered on and off to save power typically include the RF front end module and the baseband processor module.

Method and apparatus for saving power in a global positioning system receiver

The invention relates to a method for performing positioning, in which a spread spectrum signal modulated with a repetition code and transmitted by satellites, is received. The method comprises the steps of performing acquisition to the received, spread spectrum modulated signal, measuring the code phase of the received, spread spectrum modulated signal, and receiving the ephemeris parameters of satellites which are used in the positioning. In the method an optimizing phase is performed in order to minimize a cost function. The cost function includes a fraction operator having an argument that includes at least one residual error.

Method for performing positioning and an electronic device

A ranging receiver ( ) including a cellular module ( ), for providing time according to a positioning system to enable synchronizing a wireless system to the positioning system. The ranging receiver ( ) includes both the cellular module ( ) and a main module ( ) that provides ranging receiver functionality. When the cellular module ( ) receives a time-stamped frame from the wireless system, it sends a trigger signal over a special hardware path to the main module ( ), which then relates the time of trigger receipt to time according to the positioning system by calculating a position-velocity-time (PVT) solution, using a local clock ( ) to get the difference in time between receipt of the trigger and the instant to which the PVT solution applies, and then communicates to the cellular module ( ) when it received the trigger, according to positioning system time.

Method, apparatus and system for synchronizing a cellular communication system to GPS time

The invention relates to a method for performing positioning, in which a spread spectrum signal modulated with a repetition code and transmitted by satellites, is received. The method comprises the steps of acquiring the received, spread spectrum modulated signal, measuring the code phase of the received, spread spectrum modulated signal, and receiving the Ephemeris parameters of satellites which are used in the positioning. Furthermore, in the method, said code phase measurement results are stored, which have been measured at least partly before receiving the Ephemeris parameters, wherein the stored measurement results are used in the positioning after the Ephemeris parameters have been received.

A system, apparatus and corresponding method for time synchronization, using cellular signal bursts, of for example a global positioning system (GPS) receiver. To synchronized a main module, with access to a clock, to the reference time provided by a cellular communication system via a cellular communication signal, the method includes the steps of: a) having a cellular module respond to the cellular communication signal indicating a time-stamp, by providing a trigger pulse derived from the data component of the cellular communication signal, and also by providing information indicating a time-mark relating the trigger pulse to a universal time; b) having the main module, with access to the clock that provides a signal indicating local time, respond to the information indicating the time-mark; c) communicating the trigger pulse to a timing register coupled to the main module, the communicating being performed via a special hardware path that provides the trigger pulse without substantial random delay; d) having the timing register respond to the signal indicating local time, and also respond to the trigger pulse, by holding information indicating, in local time, when the trigger pulse is received by the timing register; and e) having the main module access the timing register and so obtain the time when the trigger arrives, and further having the main module determine the difference between when the information indicating the time-mark arrives and when the trigger arrives.

Method, apparatus and system for GPS time synchronization using cellular signal bursts

A generalized positioning system, corresponding method, and filter for use in the generalized positioning system, based on Kalman filtering or any other kind of filtering that produces an estimate of position, or other aspect of the motion of an object, using statistical measures involving current and previous measurements of position or any other aspect of the motion of the object, but with greater responsiveness than a positioning system based on the usual statistical filtering, such as Kalman filtering. The generalized positioning system uses a calculated association probability for each measurement in a set of measurements of position (or other aspect of the motion) at a particular instant of time, the association probabilities being used in the calculation of a combined measurement innovation (residual), which is in turn used in calculating the next estimate of position (or other motion state information). In one aspect of the invention, a pre-validation is performed, based on a usually pre-determined gate width of a validation region. By using a combined measurement innovation, the generalized positioning system is able to accept simultaneous measurements from different sources of information, including different kinds of sources of information, so that it can provide position estimates (or estimates for other components of the state of motion, i.e. of other aspects of the motion) based on, e.g., information received both from satellites, used in a global positioning system, and also from cellular base station in a cellular telephone network.

Generalized positioning system based on use of a statistical filter

A method for defining the reference time error of a receiver in a positioning means includes receiving a code-modulated signal transmitted by satellites, produced by an individual code for each satellite and modulated at least with binary modulation information. Positioning is conducted to define the reference time error, and an error value is calculated using the defined location. The minimum of the error value is searched by defining the receiver location using at least two different satellite locations corresponding to the signal time of transmission and by calculating an error value for said at least two locations of the receiver. The reference time error is defined using the searched minimum of the error value. In the receiver, the moment of bit change in the modulation information is defined, wherein said moment of bit change is used for specifying the error of the reference time.

Method for defining the error of reference time and an electronic device

A positioning system including a measurement engine, a model selector and model bank, and a filter, which is preferably a statistical filter. The measurement engine is responsive to information provided by a source of range information, from which a measurement of the state of motion of an object (including for example the position of the object) can be determined, and provides a succession of measurements of the state, each corresponding to a different instant of time. The model selector and model bank selects at least one motion model for use in estimating the state for a segment of the motion of the object. The filter is responsive to the succession of measurements of the state, and further responsive to a model mixing parameter and to the selected motion models. It determines a succession of multiple-model state estimates, preferably according to the so-called interacting multiple-model.

Multiple-model navigation filter with hybrid positioning

The present invention relates to a method for selecting satellites (SV -SV ) to be used for positioning in a positioning system. The positioning system comprises information on the orbits of the satellites (SV -SV ). In the method, at least one satellite (SV -SV ) to be searched for is selected at a time, and a searching step is performed to find out if the signal transmitted by at least one selected satellite (SV -SV ) can be received. In the method, at least a first searching step and at least one continued selection step are performed, wherein in the continued selection step, at least one satellite (SV -SV ) is selected at least partly on the basis of the findings of the previous searching step. The selection step is followed by the satellite searching step.

Method for determining a position, a positioning system, and an electronic device

The invention relates to a method for determining the phase of information modulated in a code-modulated signal transmitted by a satellite in a receiver (MS). In the method, at least partly the same information is transmitted from at least a first and a second satellite (SV -SV ) substantially simultaneously, the code-modulated signal transmitted from at least the first and the second satellite (SV -SV ) is received, and at least the received signal of the first satellite is demodulated to determine the transmitted information. The method further comprises at least a first acquisition step, in which the receiver is synchronized with the signal of at least the first satellite (SV ); a determination step, in which said demodulated signal of the first satellite (SV ) is used to determine the phase of information modulated in the signal; a computing step to compute the difference in propagation time of the signal transmitted by said first satellite (SV ) and the signal transmitted by the second satellite (SV ) from the satellite (SV , SV ) to the receiver (MS); a second acquisition step, in which the receiver is synchronized with the signal of the second satellite on the basis of the difference in propagation time computed in the computing step; and an integration step to receive the signal of the second satellite and to integrate epochs of a certain length to improve the demodulatability of the signal.

Method for determining the phase of information, and an electronic device

A positioning system based on an extended Kalman filter (EKF), or other filter, responsive to measurements provided on the basis of information received from, in some applications, cellular base stations, as well as, optionally, satellites, where, in the case of measurements by satellites, and also in other aspects of the invention as used with cellular positioning data, the EKF is modified for greater responsiveness based on use of calculated association probabilities for each measurement in a set of measurements of position at a particular instant of time, the association probabilities used in the calculation of a combined measurement innovation (residual) used in calculating the next estimate of position (and other state information, including velocity). By using a combined measurement innovation, the positioning system is able to accept simultaneous measurements based on information received from different sources of information, including both satellites and cellular base stations.

Method and apparatus for filtering measurements used in a generalized positioning system

A code modulated signal transmitted by satellites (SV -SV ) and formed by an individual code for each satellite (SV -SV ) is received. At least one reference point (B) is selected, whose position is substantially known. Information is transmitted to the positioning means (S, MS) about the position of the at least one reference point, and about Ephemeris data on the satellites (SV -SV ). Thus, at least the Ephemeris data on each of the satellites (SV -SV ) to be used in the positioning and the location of the at least one reference point are used in the positioning of the receiver.

A system, apparatus, and corresponding method for measuring a pseudorange from a ranging receiver to a beacon (such as a GPS satellite). It determines the time of transmission of a target ranging signal fragment (for which the difference in time between transmission and reception is essentially the pseudorange) even in poor signal conditions when the navigation data of the ranging signal cannot be accurately decoded by the ranging receiver. It is based on making either an estimate of the start time for the particular information element of the ranging signal (usually a navigation data bit) beginning just before the target ranging signal fragment (if the quality of the ranging signal allows such an estimate to be made), or (in any case) based on making an estimate of the time corresponding to the start of the code epoch of the ranging signal that just precedes the target ranging signal fragment.

Method and apparatus for calculating pseudorange for use in ranging receivers

A method and apparatus for measuring time related to satellite navigation data messages used with a satellite-based global positioning systems (GPS). A first record of at least a portion of a satellite data message is received at an entity, which is typically a base station of a wireless communication system. The first record is compared with a second record of the same satellite data message (navigation message) received by a GPS receiver. From the comparison, a time is determined indicating when the satellite date message was transmitted (broadcast). The comparison is made in a way that accounts for the only approximate removal of all modulation of the satellite data message by the acquisition and tracking stages of the GPS receiver.

Growing community of inventors

Tampere, Finland

Jari Syrjärinne

Growing community of inventors

Tampere, Finland

Jari Syrj&auml;rinne

Jari Syrjärinne