RU2386142C2 - Position finding support using satellites - Google Patents

Abstract

FIELD: physics.

SUBSTANCE: communication system converts parametres of a special-purpose orbital model, which describes movement of a satellite given for a specific satellite position finding system, to parametres of a general orbital model which describes movement of the satellite. Alternatively or additionally, a network replaces a reference value, which is based on the time of the satellite position finding system and is included in the parametres of the orbital model, by a reference value which is based on the time of the communication system. After conversion of the parametre and/or replacement of the reference value, parametres are given as part of auxiliary data for satellite position finding. Alternatively or additionally, a set of data which is independent of the position finding mode used is sent in one direction between a mobile device and the communication system.

EFFECT: increased accuracy of locating a mobile device.

17 cl, 2 dwg

Description

FIELD OF TECHNOLOGY

The invention relates to methods for supporting satellite positioning of a mobile device with auxiliary data and using auxiliary data. Equally, the invention relates to network elements for a communication system supporting satellite positioning of a mobile device with auxiliary data, and to mobile devices supporting satellite positioning of a mobile device using auxiliary data. Equally, the invention relates to systems including such network elements and such mobile devices. Equally, the invention relates to corresponding software codes and to related software products.

BACKGROUND

Currently, there are two working systems for satellite positioning: the American GPS system (Global Positioning System, Global Positioning System) and the Russian Global Navigation Satellite System (GLONASS). In the future, the European Galileo system (GALILEO) will appear. The common name for these systems is the Global Navigation Satellite System (GNSS).

For example, in the GPS system there are more than 20 satellites, also called space vehicles (SV, space vehicle), which are in near-earth orbits. Each of the satellites transmits two carrier signals L1 and L2. One of these L1 signals is used to carry the navigation message and the standard positioning service (SPS) code signals. The carrier phase L1 is modulated for each satellite with a different coarse capture code (C / A, Coarse acquisition). Thus, for different satellites there are different transmission channels. The C / A code is a pseudo random noise code (PRN) that distributes the spectrum over a nominal bandwidth of 20.46 MHz. It is repeated every 1023 bits, with the result that the code repeat period is 1 ms. In addition, C / A bits are also often referred to as chips. The carrier frequency of the L1 signal is further modulated with navigation information at a data rate of 50 bit / s. Navigation information includes, in particular, a time stamp indicating transmission time, ephemeris and almanac parameters.

The parameters of the GPS ephemeris and almanac mainly contain the parameters of the orbit of an artificial satellite for a short-term polynomial model of the orbit with respect to the true trajectory of the satellite. Parameters are saved and updated in the GPS management server, and then updated in satellites. Based on the available parameters of the ephemeris or almanac, the algorithm can estimate the position of the satellite for any time while the satellite moves in the framework of such a model. Polynomial orbital models have only one degree of freedom, that is, time. The reference time for the ephemeris and almanac parameters is the GPS time, namely: GPS time of the week (TOW, time of week). The calculation of the position of the satellite is carried out mainly by extrapolating the positions of satellites in orbit as a function of time, starting from a known initial position. The initial position is also determined by the current data of the ephemeris and almanac. In addition, the time stamp indicates when the satellite is in a predetermined initial orbital position. Timestamps are called ephemeris time (TOE, time-of-ephemeris) for ephemeris parameters and time-of-applicability (TOA) for almanac parameters. Both TOE time and TOA time are measured with respect to GPS TOW time.

Due to the relatively short-term suitability in the general case, the ephemeris parameters can be used only for 2-4 hours to determine the satellite position. On the other hand, with such short-term suitability, greater accuracy can be achieved than with longer-term suitability. The achievable accuracy is 2-5 m. On the contrary, the almanac parameters can be used for a rough estimate of the satellite’s position even for many weeks, but they are not suitable for the actual exact location determination due to the low accuracy due to long-term suitability, as well as a smaller number of parameters. The ephemeris and almanac data are transmitted from GPS satellites in the format defined in an open GPS control document (ICD, interface control document) called ICD-GPS-200. Currently, all GPS receivers must support this format.

The GPS receiver, the location of which you want to determine, receives signals transmitted by currently available satellites, and at the same time detects and tracks the channels used by different satellites, based on different C / A codes. To capture and track a satellite signal, first of all, the signal received by the radio frequency (RF) unit of the GPS receiver is converted to the frequency of the base band. In the main band, frequency errors, for example, due to the Doppler effect, are eliminated by the mixer. The signal is then correlated using reference codes that are available to all satellites. Correlation can be performed, for example, using a matched filter. The correlation values can then be integrated coherently and / or incoherently to increase reception sensitivity. The correlation value exceeding a certain threshold value indicates the C / A code and the phase of the code, which are necessary to remove the spread of the signal spectrum and, thus, to restore the navigation information.

The receiver then determines the code transmission time for each satellite, usually based on data in decoded navigation messages and counts of sampling periods and C / A code chips. The transmission time and the measured arrival time of the signal at the receiver allows you to determine the transit time required for the signal from the satellite to reach the receiver. When we multiply this time by the speed of light, we get the distance or range between the receiver and the corresponding satellite. In addition, the receiver estimates the position of the satellites during transmission, usually based on the ephemeris parameters in the decoded navigation messages.

The calculated distances and estimated positions of the satellites then allow us to calculate the current location of the receiver, since the receiver is located at the intersection of distances from the set of satellites.

Similarly, the general idea for positioning in a GNSS system is to receive satellite signals at a receiver whose position you want to determine, measure the time it takes to propagate the signals from the estimated position of the satellite to the receiver, calculate based on this time the propagation distance between the receiver and the corresponding satellite, and then calculating the current position of the receiver using, in addition, the estimated positions of the satellites. It is expected that the European Galileo satellite navigation system will have its own ICD documents. According to the L1 band part of Galileo Signal in Space ICD (SIS ICD) project, 2005, developed by Galileo Joint Undertaking, the Galileo ICD documents will be very close to the GPS ICD documents, but will not coincide with them. The ephemeris and almanac data for the Galileo system will be available, and both groups of parameters will be correlated with the time of the Galileo system.

GPS positioning can be performed in three different positioning modes. The first mode is autonomous GPS based positioning. This means that the GPS receiver receives signals from GPS satellites and calculates its position from these signals without any additional information from other sources. The second mode is GPS-based positioning using a network of mobile stations. In this mode, the GPS receiver can be connected to a mobile device. The GPS receiver can be integrated into a mobile communication device or be an accessory for a mobile communication device. The mobile communication system provides auxiliary data that is received by the mobile communication device and transmitted to the GPS receiver to improve its performance. Such auxiliary data may be, for example, at least ephemeris data, position and time information. Location calculations in this case are also performed at the GPS receiver. The third mode is GPS positioning based on networked mobile stations. In this mode, the GPS receiver is also connected to a mobile device. In this mode, the mobile communication system at least helps to collect data and obtain temporary information through the mobile communication device, as well as transmitting it to the GPS receiver to support measurements. Then, the measurement results via a mobile communication device are supplied to a mobile communication system that performs location calculation. The second and third approaches are also collectively called "non-autonomous GPS systems" (A-GPS, assisted-GPS). If the auxiliary data includes, for example, the starting position and ephemeris data for a particular satellite, the GPS receiver can determine the approximate position of the satellite and its movement, and thus limit the possible propagation time of the satellite signal and the resulting Doppler frequency. If the propagation time range and Doppler frequency are known, you can also limit the possible phases of the codes that need to be checked.

Ancillary data for A-GPS is defined and standardized for all cellular systems. Ancillary data is built on top of the specific protocols of the cellular communication system, namely: RRLP for the Global System for Mobile Communications (GSM), IS-801 for Code Division Multiple Access (CDMA), RRC for CDMA Broadband Access (WCDMA , Wideband CDMA) and OMA SUPL. Mobile station mode is currently being implemented on a CDMA network in the United States to locate the location of an alarming entity.

All cellular protocols have many common features, such as support for GPS modes. Thus, all cellular protocols support GPS systems based on mobile stations, GPS systems using mobile stations and autonomous GPS systems. In addition, all protocols are highly dependent on GPS. As stated above, the assist data provided for the A-GPS cellular communication system may include satellite navigation data, including ephemeris and GPS almanac data. All cellular protocols for GPS assist data define for this information elements (IE, information element) for ephemeris and almanac data with only slight differences. The ephemeris and almanac information elements defined in cellular protocols are virtually identical to those defined in ICD-GPS-200. Thus, they have the same limitations and expected accuracy as the data of the ephemeris and almanac, which are broadcast by satellites. This correspondence makes it easier for the GPS receiver to use ancillary data in location calculations, since it actually does not require conversions or additional software. In addition, according to all cellular cellular protocols, a GPS ionosphere model is being sent. According to all cellular protocols, GPS assist data elements are associated with GPS time. In addition, according to all cellular protocols, data collection assistance is organized specifically for GPS and cannot be used to calculate location in a mobile station. Finally, according to all cellular protocols, all data elements are indexed according to the combination of GPS satellites.

However, although there are common features in all GPS-related cellular protocols, there are differences. This means that the software of the terminal receiving the ancillary data must either have an adaptation level for cellular protocols, or support only some of the cellular protocols. In addition, differences in cellular protocols, especially in message content, affect A-GPS performance in terms of time to first setup and sensitivity.

An additional problem is to use the parameters of the ephemeris or almanac to accurately predict the phases of the satellite codes and Doppler frequencies in the GPS receiver for the initial capture of signals, and the auxiliary data from the network should also include accurate GPS TOW data. In GSM and WCDMA networks, accurate TOW GPS delivery requires the deployment of LMUs (Location Measuring Units) in each cellular base station, which are capable of directly collecting and evaluating GPS signals. However, the blocks measure the location of the road and require continuous maintenance.

In addition, current ephemeris and almanac data formats in cellular protocols are based on formats specifically defined for GPS. Supporting data will also be important for the Galileo system to ensure that the Galileo system is compatible with A-GPS. It can be expected that the format of the ephemeris in the Galileo system will be different from the formats of the ephemeris and GPS almanac, so that the Galileo will not be able to simply use the format of GPS auxiliary data. If the Galileo ephemeris is different from the GPS ephemeris, cellular standards should be expanded to specific information elements of the Galileo system, and the use of the Galileo system for determining the location requires additional software in the receivers. In addition, the Galileo and GPS can have different quality of service, that is, the Galileo ephemeris data can have greater accuracy than the GPS ephemeris data, which will lead to greater accuracy in determining the location based on the Galileo system. In addition, the parameters of the Galileo and GPS ephemeris systems can have different validity periods. In this case, simultaneous updating of auxiliary data is not possible, and updating of auxiliary data should be planned independently for the Galileo and GPS systems.

Thus, there are various problems with the current GPS assist data.

It was proposed to expand the 3GPP GPS auxiliary data elements for Galileo system signals by modifying the indexing of the ephemeris data elements so that the indexing could also include Galileo satellites. The ephemeris data format would then essentially be the same for the Galileo and GPS satellites. In such a solution, both the GPS assist data and the Galilee would still fall within the limitations of the current GPS ephemeris and almanac data, and in addition, TOE GPS delivery would still be necessary.

In addition, it is known to improve the accuracy and integrity of orbital models by means of corrective data. For example, the European Geostationary Navigation Overlay Service (EGNOS) and the Wide Area Augmentation System (WAAS) determine GPS correction data that takes into account, for example, GPS signal delay due to the atmosphere and ionosphere. Correction data is transmitted via geostationary satellites, and this data can be received by the respective GPS receivers and used to improve the accuracy of GPS-based positioning. In addition, differential GPS corrections (DGPS) were introduced to mitigate the effects of selectivity. They are suitable for eliminating the effects of the atmosphere, satellite position and synchronization drift. However, WAAS, EGNOS, and DGPS corrections are always tied to a single set of ephemeris. When long-term satellite orbital parameters are used instead of normal ephemeris parameters, WAAS, EGNOS, and DGPS corrections cannot be used because they are tied to normal ephemeris data.

SUMMARY OF THE INVENTION

The present invention provides alternatives to the conventional provision and use of satellite data for satellite positioning of a mobile device.

I.

According to a first aspect of the present invention, the first method is designed to support satellite positioning of a mobile device using auxiliary data, the mobile device being configured to communicate with a communication system and receive signals transmitted by satellites of at least one satellite positioning system. The method includes converting in the communication system the available parameters for a specialized orbital model that describes the satellite’s motion, and this specialized orbital model is defined for a specific satellite positioning system, into the parameters of a common orbital model that describes the satellite’s motion. In addition, the method includes providing transformed parameters as part of ancillary data for satellite positioning.

In addition, according to a first aspect of the present invention, there is provided a second method for supporting satellite positioning of a mobile device using auxiliary data, the mobile device being configured to communicate with a communication system and receive signals transmitted by satellites of at least one satellite positioning system. This method includes receiving a mobile device auxiliary data from a communication system, including the parameters of a common orbital model that describes the movement of the satellite. In addition, the method includes assessing the position of the satellite in at least one satellite positioning system based on the received parameters of the common orbital model.

In addition, according to a first aspect of the present invention, there is provided a network element for a communication system supporting satellite positioning of a mobile device using auxiliary data, the mobile device being configured to communicate with a communication system and receive signals transmitted by satellites of at least one satellite positioning system . The network element comprises processing means. The processing means is configured to convert the available parameters of a specialized orbital model that describes the satellite’s motion, and this specialized orbital model is defined for a specific satellite positioning system, into the parameters of a common orbital model that describes the satellite’s motion. In addition, the processing means is configured to provide converted parameters as part of the auxiliary data for satellite positioning.

In addition, according to a first aspect of the present invention, there is provided a mobile device supporting satellite-based positioning of this mobile device using auxiliary data. The mobile device includes a satellite signal receiver configured to receive signals transmitted by satellites of at least one satellite positioning system. The mobile device further comprises a communication component configured to receive auxiliary data from the communication system with parameters of a common orbital model describing the movement of the satellite. In addition, the mobile device comprises processing means adapted to estimate the position of the satellite within the framework of at least one satellite positioning system based on the received parameters of the common orbital model.

In addition, according to a first aspect of the present invention, there is provided a system that comprises a network element proposed for the first aspect of the present invention and a mobile device proposed for the first aspect of the present invention.

In addition, according to a first aspect of the present invention, there is provided a first program code for supporting satellite positioning of a mobile device with auxiliary data, the mobile device being configured to communicate with a communication system and receive signals transmitted by satellites of at least one satellite positioning system. When executed by a processing unit of a network element of a communication system, this program code provides an implementation of the first method for the first aspect of the present invention.

In addition, according to a first aspect of the present invention, there is provided a first computer program product in which a first program code proposed for the first aspect of the present invention is stored.

In addition, according to a first aspect of the present invention, there is provided a second program code for supporting satellite positioning of a mobile device using auxiliary data, the mobile device being configured to communicate with a communication system and receive signals transmitted by satellites of at least one satellite positioning system. When executed by the processing device of the mobile device, the program code provides an implementation of the second method for the first aspect of the present invention.

In addition, according to a first aspect of the present invention, there is provided a second computer program product in which a second program code proposed for the first aspect of the present invention is stored.

A first aspect of the invention is that the format of the orbital model parameters that are provided as supporting data for satellite positioning is separated from the format of the orbital parameters that are defined within the corresponding satellite positioning system. Therefore, it is assumed that the available orbital parameters for a particular satellite positioning system are converted to the parameters of a common orbital model. A common orbital model may, but not necessarily, be determined simultaneously for at least two satellite positioning systems. It should be noted that the term “transformation” also covers the recalculation of parameters for a common orbital model.

An advantage of the first aspect of the present invention is that the same orbital model can be used for auxiliary data of various satellite positioning systems. In a common orbital model, performance accuracy close in terms of accuracy can be achieved for all supported satellite positioning systems. In addition, it is easy to add new satellite positioning systems. Thus, positioning using ancillary data, such as A-GNSS, could be consistent with various communication standards, for example with all cellular standards. In addition, in mobile devices, a common orbital model facilitates hybridization, such as the Galileo-GPS hybridization, which allows calculations to determine the location of a mobile device using satellite signals from GPS satellites and Galileo satellites. In addition, you can use the common orbital model in as the only orbital model for a specific satellite positioning system, for example, instead of the GPS ephemeris and almanac model, and equally as the only orbit A generic model for all location modes, such as a GNSS system involving a mobile station and a GNSS based on a mobile station, thus using a common orbital model reduces the number of data elements that must be supported in communication standards. Size and complexity of the software for determining locations in a mobile device can be reduced by using a common orbital model in a mobile device, possibly for a GPS / Galileo hybrid receiver, which costs b Without autonomous location. Thus, if the mobile device itself does not have any software for decoding satellite navigation data, but only has software that supports the proposed general orbital model, the system is operable, although this case is not a preferred embodiment of the present invention. In addition, the same general orbital model can even be used to provide supporting data for terrestrial positioning systems.

In addition, an advantage of the first aspect of the present invention is that possible changes in the parameter format of specialized orbital models, such as the parameters defined in ICD-GPS-200, do not require changes in the converted parameters. Thus, the interface between the communication system and mobile devices can remain unchanged. Only the conversion of the current parameters should be adapted.

In addition, an advantage of the first aspect of the present invention is that the format of the converted parameters is not associated with the format of the original parameters. Thus, the conversion ensures the provision of advanced parameters and, thus, improving the performance of positioning using auxiliary data.

A general orbital model may, for example, include more parameters than a specialized orbital model, or parameters with a longer word length than the corresponding parameters for a specialized orbital model. This improves the accuracy of the orbital model and / or the suitability time of the corresponding parameters. If the orbital model is more accurate, then the resulting location may have greater accuracy. If the parameters are suitable for a longer time, fewer updates are required, which saves bandwidth in the communication system.

The Jet Propulsion Laboratory of the California Institute of Technology (JPL) has already demonstrated that it is possible to improve the accuracy and lifetime of orbital models for artificial satellites by increasing the word length of orbital parameters. The International GPS Service (IGS), using the JPL developments, ensures high accuracy of the orbital model for 48 hours using the Internet. JPL publishes so-called ultrafast orbital location data that is valid and provides decimeter order accuracy of at least ± 24 hours, that is, 24 hours ahead. Typically, the data is in sp3 format, which contains the coordinates of the satellite’s position and speed in the coordinate system “Earth in the center and the Earth is stationary” (ECEF, Earth Centered Earth Fixed), time and accuracy estimates selected for a certain interval, typically 15 min. Data is provided for all GPS satellites. The data themselves are not suitable for determining the location of the terminal, but must be modeled, for example, approximated by a polynomial, which gives a compact set of parameters for the terminal, which allows to determine the positions of satellites and their speeds by extrapolation depending on time. For polynomial approximation, you can use the "polynomial format" defined for GPS ephemeris data. In addition, modeling is necessary to account for the drift of satellite clocks. IGS provides accurate information for satellite clocks, which also need to be modeled, for example, also in the form of polynomials. The watch model is included in standard satellite broadcasting in subframe 1 in accordance with the ICD GPS document and is also provided in ancillary data from the cellular system. It is usually assumed that the watch model is part of the ephemeris, but it still remains an independent model.

Global Locate Inc. Already demonstrated that it is possible to increase the accuracy and lifespan of models for artificial satellite orbits by calculating ICD-GPS-200 compatible polynomials using an alternative fitting criterion compared to that used in GPS. Ephemeris Satellite Service at Global Locate Inc. uses the ICD-GPS-200 format to transfer long-term orbital models for all GPS satellites. The lifespan of a long-term model can far exceed the lifetime of translated ephemeris. However, the latter approach is still tied to the GPS ephemeris format.

The available parameters of a specific orbital model can be, for example, translatable ephemeris parameters or other orbital data, ephemeris data or other orbital data supplied by GNSS control segments, and / or ephemeris data or other orbital data supplied by an external source, such as IGS.

A common orbital model can be based on Keplerian orbits and parameters used for the ephemeris and GPS almanac models. But to simulate information about the position of the satellite, you can also use various other representations. Examples include splines, Hermite polynomials, piecewise continuous polynomials, etc. For example, a model based on fourth-order polynomials can be adapted to describe the true trajectory of a satellite’s orbit, issued in an ECEF frame. The polynomial model can be adjusted using a criterion that minimizes the root mean square error (RMSE, root mean of squared errors). Then the polynomial model can be used to extrapolate information about the position of the satellite into the future.

Thanks to the sp3 format, which includes the ECEF position, ECEF speed and clock offset / drift accuracy (standard), IGS data is convenient to use, for example, when fitting to a polynomial. Simulation can be performed, for example, by fitting with splines or Hermite polynomials, so that the polynomials are adjusted to the position and speed of the satellite over the previous 24-48 hours. In the proposed general orbital model, there is more freedom for choosing parameters compared to the simple use of the “polynomial format” defined for GPS ephemeris data. The order of the polynomial, the number of parameters and the length of the codes can be selected according to the desired accuracy and the expected term of use of this fit.

Common orbital reference parameters, which are ultimately provided as part of the auxiliary data, may include parameters for the entire satellite group in a particular satellite positioning system, for the entire satellite group for multiple satellite positioning systems, or for part of one or more satellite groups, depending from the capabilities of a mobile device.

Supported satellite positioning systems can be arbitrarily selected. These may include, for example, GPS, GLONASS and Galileo, but equally EGNOS, WAAS, etc.

In addition to the converted parameters, the auxiliary data provided may include, in particular, a reference time, for example in the form of parameters of a watch model, and a spatial reference point. It should be noted that even the general orbital model itself may contain, in addition to a model for satellite position and speed data, a model for satellite clock offset and drift, a reference point for initialization, an estimate for the position, satellite speed, clock accuracy, and possibly , also a model for taking into account the influence of the phase correction on the satellite position when calculating the exact point position (PPP, precise point positioning). The reference system for position and velocity models is preferably the ECEF coordinate system, since it can easily be corrected due to terrestrial rotation. Conversion to local coordinate systems (east-north-up) can be achieved by simple matrix multiplication. IGS data can be summarized in the ECEF coordinate system.

In addition, the supporting data provided may include various other information. Examples are DGPS correction data, real-time kinematics correction data (RTK, Real Time Kinematics) and carrier phase measurements for satellite signals. For high accuracy RTK positioning, see WO 2004/000732 A1. Carrier phase measurements and RTK reference values are suitable, for example, to provide highly accurate positioning. It should be understood that the RTK correction data known to GPS can be adapted as necessary to support positioning based on the Galileo system, etc. Examples of additional supporting data include EGNOS and WAAS correction data. Broadcasting data from geostationary satellites EGNOS and WAAS is difficult to receive in high latitude areas. Therefore, as an alternative, this data can be provided as auxiliary network data, especially if the common orbital model is a short-term orbital model, since the current EGNOS / WAAS correction data are not suitable in themselves for long-term orbital models. Another example of additional supporting data is short-term differential correction data for long-term orbital models. Another example of additional supporting data is the parameters of the ionosphere model and / or the parameters of the troposphere model. Another example of additional supporting data is short-term integrity warnings, which can be presented in the event of a sudden satellite failure, in order to exclude this satellite when calculating a location. Another example of additional auxiliary data is the data bits for at least one satellite positioning system that allows erasing data after a request from a mobile device. Erasing data is a way to increase the sensitivity of a satellite signal receiver. For example, if the content of the GPS data is not known, you can coherently integrate GPS signals only for 20 ms (1 bit GPS). If the data bits are known, the integration of the coherent signal can be continued by more than a few GPS bits, which provides a sensitivity increase of approximately 1.5 dB for each doubling of the integration time. For example, 40 ms (2 bits) can provide 1.5 dB gain, and 80 ms (4 bits) can provide 3 dB gain.

In one embodiment of the present invention, the same or another network element in a communication network further replaces the reference value in the converted parameters, which is based on the time of the satellite positioning system, with such a reference value, which is based on the time of the communication system. Thus, the general orbital model refers only to the time of the communication system, and thus information about the position of the satellite can be calculated as a function of the time of the communication system instead of, for example, the time of GPS or Galileo systems.

The time base of the communication system can be used if the relationship between the times of the GNSS system and the communication system is known exactly, which allows us to predict the exact phase of the signal and the Doppler effect to achieve high sensitivity. For the time of the communication system, additional areas may be provided in the auxiliary data, depending on the particular communication system. System-specific information can be a frame, slot and bit for GSM, a system frame number, a slot and a chip for WCDMA, and UTC world time for CDMA. Accounting for a slot and a bit or a chip in GSM and WCDMA, respectively, provides sufficient resolution. The fields may also contain a time uncertainty estimate (standard) for estimating the uncertainty in the predictions of the signal phase and Doppler effect.

In yet another embodiment of the present invention, a common orbital model refers to two time bases, for example, world time and / or communication system time. World clock provides a universal time reference system for all GNSS systems and allows you to estimate the number of possible specific frame / super-frame scrolls, for example, for cellular communication systems. A world time reference system is also suitable for resolving the problem of possible differences in GNSS systems. GPS, Galileo and GLONASS systems have different system times. Thus, offsets between system times should be known if the systems are used in a hybrid arrangement, for example, using a single GPS signal to predict the phase of the Galileo system signals. This problem is resolved by placing the model in a common time base, that is, in world time. Differences between GNSS system times can be compensated for in the watch model. For example, in the general watch model, a continuous fit with a second-order polynomial, which has three parameters: displacement, drift, and throw, can be used. Roughly speaking, this is roughly the same as the watch model in the current GPS ICD standard. However, any other model may also be used. A watch model may also include an estimate of accuracy or uncertainty for clock error. World clock can also be a timestamp / identifier for an orbital model.

Auxiliary data can be transmitted to a specific mobile device, in particular, after a request by this mobile device. Alternatively, however, they can also be transmitted, for example, to the appropriate cell of a cellular communication system.

Then, the mobile device receiving the auxiliary data can estimate the satellite position of at least one satellite positioning system using the transformed parameters.

II.

According to a second aspect of the present invention, the first method is designed to support satellite positioning of a mobile device with auxiliary data, the mobile device being configured to communicate with a communication system and receive signals transmitted by satellites of at least one satellite positioning system. The method includes replacing the reference value in the communication system, which is based on the time of the satellite positioning system in the available parameters of the orbital model describing the satellite’s movement, by the reference value, which is based on the time of the communication system. The method further includes providing parameters including the replaced reference value as auxiliary data for satellite positioning.

Furthermore, according to a second aspect of the present invention, there is provided a second method for supporting satellite positioning of a mobile device using auxiliary data, the mobile device being configured to communicate with a communication system and receive signals transmitted by satellites of at least one satellite positioning system. This method includes receiving a mobile device auxiliary data from a communication system, including a time stamp, which is based on the time of the communication system. The method further includes determining the time of the communication system in the mobile device. The method further includes evaluating in the mobile device the satellite position of at least one satellite positioning system using parameters in the auxiliary data based on the determined time of the communication system.

In addition, according to a second aspect of the present invention, there is provided a network element for a communication system supporting satellite positioning of a mobile device with auxiliary data, the mobile device being configured to communicate with a communication system and receive signals transmitted by satellites of at least one satellite positioning system. The network element includes a processing means. The processing means is intended to replace the reference value, which is based on the time of the satellite positioning system in the available parameters of the orbital model describing the movement of the satellite, by the reference value, which is based on the time of the communication system. In addition, the processing means is configured to provide parameters, including a replaced reference value, as part of the auxiliary data for satellite positioning.

In addition, according to a first aspect of the present invention, there is provided a mobile device supporting satellite-based positioning of the indicated mobile device itself using auxiliary data. The mobile device includes a satellite signal receiver configured to receive signals transmitted by satellites of at least one satellite positioning system. The mobile device further comprises a communication component configured to receive auxiliary data from the communication system with a time stamp, which is based on the time of the communication system. The mobile device further comprises processing means configured to determine a communication system time. The mobile device further includes processing means adapted to estimate a satellite position of at least one satellite positioning system using parameters in received auxiliary data based on a specific time of the communication system.

In addition, according to a second aspect of the present invention, there is provided a system that comprises a proposed network element for a second aspect of the present invention and a proposed mobile device for a second aspect of the present invention.

Furthermore, according to a second aspect of the present invention, there is provided a first program code for supporting satellite positioning of a mobile device with auxiliary data, the mobile device being configured to communicate with a communication system and receive signals transmitted by satellites of at least one satellite positioning system. When executed by a processing unit of a network element of a communication system, the program code provides an implementation of the first method for the second aspect of the present invention.

In addition, according to a second aspect of the present invention, there is provided a first computer program product in which a first program code proposed for the second aspect of the present invention is stored.

In addition, according to a second aspect of the present invention, there is provided a second program code for supporting satellite positioning of a mobile device using auxiliary data, the mobile device being configured to communicate with a communication system and receive signals transmitted by satellites of at least one satellite positioning system. When executed by the processing device of the mobile device, the program code provides an implementation of the second method for the second aspect of the present invention.

In addition, according to a second aspect of the present invention, there is provided a second computer program product in which a second program code proposed for the second aspect of the present invention is stored.

The second aspect of the invention is based on the idea that the position of the satellite can be estimated based on the parameters of the orbital model using the time of the communication system instead of the time of the satellite positioning system. To allow such an assessment, it is proposed that the reference value in the available parameters, which is based on the time of the satellite positioning system, be replaced by a reference value based on the time of the communication system. For example, in the case of GPS ephemeris parameters, ephemeris time (TOE) is replaced by the communication system time, and in the case of GPS almanac parameters, the almanac time (TOA) is replaced by the communication system time. In order to replace the reference values, as suggested above, in the communication system, the relationship between the time of the satellite positioning system and the time of the communication system should be known. But since the accuracy of the time ratio is not very rigid, this ratio can be made available to the network in several ways.

An advantage of the second aspect of the invention is that the auxiliary data is made time-independent of the satellite positioning system and that the time of the satellite positioning system does not need to be available for the mobile device.

The second aspect of the present invention can be used for any supported satellite positioning system, for example, for A-GPS or a supported Galileo system.

If the communication system is, for example, a GSM network, the time of the communication system can be determined by an appropriate combination of frame number, time slot and bit number. If the communication system is, for example, a WCDMA network, the time of the communication system can be determined by the corresponding system frame number, slot and chip. For example, all modern cellular terminals are already able to decode the frame number. Thus, suitable time information is already available for calculating the position of the satellites, that is, for extrapolating the positions of the satellites using the time of the cellular communication system.

In the case of GPS, it is easy to extend the current GSM standard and the WCDMA cellular standard using cellular time stamps. Already there are information elements and parameters for accurate time transmission. The same parameters can be added to the ephemeris and almanac information elements, which are used instead of the ephemeris time and almanac time, but have the same time information and are used as TOW. This approach would have backward compatibility.

The mobile device may receive auxiliary data with the replaced reference value from the communication system. It can then determine the time of the communication system and estimate the satellite position of at least one satellite positioning system using parameters in the auxiliary data based on the time of the communication system. Even though the time of the satellite positioning system was not transmitted to the mobile device, with information about the position of the satellites, accurate prediction of the phases of the codes and Doppler frequencies in the received satellite signals is provided, as is known to specialists in this field of technology.

A mobile device that receives auxiliary data from a communication system may provide a predetermined set of feedback elements to the default communication system. In existing approaches, the set of feedback elements depends on the positioning mode, that is, on whether the location determination is based on the mobile station or is carried out only with the participation of the mobile station. Feedback data may include position information, for example, a specific position of a mobile device, a specific speed of a mobile device, a specific time of at least one satellite positioning system, and detected uncertainties in measurements and / or position. The feedback data may further include measurements based on the received satellite signals and / or the relationship between the time of the satellite positioning system and the time of the communication system. Feedback data may also include Observed Time Difference (OTD) measurements made on signals received from a plurality of base stations of a communication system. To make the information independent, the mobile device can return OTD measurements to the communication system not in the form of a difference of frames or subframes, but in fractions of a second, i.e. microseconds or nanoseconds.

It may also be required that the mobile device processes the relationship between the time of at least one satellite positioning system and the time of the communication system. If the mobile device has received a GNSS location, it can bind to it the current time of the communication system, for example, in units of a frame, subframe, slot, bit and chip, using a specific time of the satellite positioning system. Alternatively, the mobile device may receive the initial time ratio as auxiliary data. The time ratio can be processed, for example, by evaluating the time difference information from the network, evaluating the OTD measurements made on the mobile device, and re-setting the universal coordinated time (UTC) to cellular time ratio if the uncertainty in the ratio is too large, or by estimating GNSS support time from the network. For example, in CDMA networks, GPS and UTC times are available by default. If the mobile device has a valid time ratio, this ratio can be used to improve performance in terms of time-to-first-fix and sensitivity. Performance improvements can be achieved with a time ratio of hundreds of microseconds. The established ratio of times can also be included in the request to the communication system for auxiliary data from the mobile device.

A communication system may collect location data, time ratio data, and OTD measurements provided in the form of feedback from mobile devices to create a database of time differences between base stations. This database can be used to deliver time-accurate auxiliary data to mobile devices to increase sensitivity without delivering time to the satellite positioning system as such. If the mobile device is not able to calculate the result of the location, satellite feedback measurements, if any, can also be used to estimate the position of the mobile device in the communication system.

III.

According to a third aspect of the present invention, there is provided a method for supporting satellite positioning of a mobile device using auxiliary data, the mobile device being configured to communicate with a communication system and receive signals transmitted by satellites of at least one satellite positioning system, and wherein the communication system is configured to the ability to support at least two different positioning modes. The method includes transmitting at least one data set that is independent of the location mode used in at least one direction between the mobile device and the communication system as part of determining the location of the mobile device.

In addition, according to a third aspect of the present invention, there is provided a network element for a communication system supporting satellite positioning of a mobile device with auxiliary data, the mobile device being configured to communicate with a communication system and receive signals transmitted by satellites of at least one satellite positioning system. The network element includes processing means that is capable of transmitting to the mobile device at least one data set that is independent of the location mode used and / or to receive at least one data set from the mobile device that is independent of the location mode, as part of determining the location of the mobile device.

In addition, according to a third aspect of the present invention, there is provided a mobile device supporting satellite-based location of this mobile device using auxiliary data. The mobile device includes a satellite signal receiver configured to receive signals transmitted by satellites of at least one satellite positioning system. The mobile device further comprises a communication component configured to transmit at least one data set that is independent of the location mode used and / or to receive at least one data set from the communication system that is independent of the used location mode, as part of determining the location of the mobile device.

In addition, according to a third aspect of the present invention, there is provided a system that comprises a proposed network element for a third aspect of the present invention and a proposed mobile device for a third aspect of the present invention.

In addition, according to a third aspect of the present invention, there is provided a first program code for supporting satellite positioning of a mobile device with auxiliary data, the mobile device being configured to communicate with a communication system and receive signals transmitted by satellites of at least one satellite positioning system. When it is executed by the processing device of the network element of the communication system, the program code ensures the transmission to the mobile device of at least one data set that is independent of the location mode used, and / or the reception of at least one data set from the mobile device that is independent of the location mode used, as part of the location of the mobile device.

In addition, according to a third aspect of the present invention, there is provided a first computer program product in which a first program code proposed for the third aspect of the present invention is stored.

In addition, according to a third aspect of the present invention, there is provided a second program code for supporting satellite positioning of a mobile device using auxiliary data, the mobile device being configured to communicate with a communication system and receive signals transmitted by satellites of at least one satellite positioning system. When it is executed by the processing device of the mobile device, the program code transmits at least one data set that does not depend on the location mode used to the communication system, and / or receives at least one data set that does not depend on the location mode used, from a communication system, as part of determining the location of a mobile device.

Finally, according to a third aspect of the present invention, there is provided a second computer program product in which a second program code proposed for the third aspect of the present invention is stored.

A third aspect of the present invention is based on the assumption that all current supporting data standards have different technical requirements for different location modes. To combine and simplify the technical requirements and processing, it is proposed that at least one data set that is transmitted between the mobile device and the communication system as part of the positioning is essentially the same, regardless of the location mode used.

This at least one data set may belong, for example, to auxiliary data that is transmitted from a communication system to a mobile device. This ensures that the operations performed on the mobile device within the framework of satellite positioning are essentially the same regardless of the positioning mode used.

In addition, this at least one data set may relate to feedback information transmitted from a mobile device to a communication system. In this case, this at least one data set may include, for example, measurement information for satellite signals received by the mobile device. If the mobile device itself determines its position based on the received satellite signals, the determined position can be added to the overall data set.

It should be noted that the calculation of the position of the mobile device can be performed both in the mobile device and in the communication system.

IV.

Another aspect of the present invention follows from the fact that instead of calculating any kind of correction data based on normal ephemeris parameters, these correction data can be calculated based on the parameters of the long-term orbital model, which are valid for at least one day. As a result, correction data can be used with long-term orbital parameters, and not just with short-term ephemeris parameters. These parameters can be transmitted earlier than the correction data, or simultaneously with the correction data. The correction data may be, for example, WAAS, EGNOS or DGPS correction data, but also other suitable correction data or data of a new type.

In addition, the accuracy of the parameters of the long-term orbital model deteriorates over time. But using the proposed correction data, you can even extend the duration of these long-term orbital parameters.

Thus, the proposed corrective data can improve the accuracy and integrity of long-term orbital models. Since using accurate correction data, orbital data updates should occur less frequently, the amount of data that must be transmitted between the communication system and the mobile device is reduced, which reduces the bandwidth load. In addition, corrective models can be more accurate and long-term than existing models. Due to the nature of selectivity, DGPS corrections, for example, were initially seen as very short-term and not very accurate corrections. Since selectivity has now been discarded, a new type of DGPS correction can be developed with high accuracy. In addition, for all groups of satellites, such as GPS, Galileo, GLONASS, etc., a single correction data format can be used.

On the network side, the server can calculate correction data for long-term orbital models in accordance with a third aspect of the present invention. The parameters of the long-term orbital model can be valid for several days and occupy some network bandwidth when they are transferred to the mobile device as part of the auxiliary data. Correction data can be valid for several hours, but this requires less bandwidth than when transmitting parameters of a long-term orbital model. A suitable set of correction data can be calculated in various ways. Actual correction data can be calculated, for example, based on real measurements from reference stations or based on the existing EGNOS / WAAS model. The type of actual correction data does not depend on how they are calculated.

On the side of the mobile device, correction data is received and used to correct the parameters of the long-term orbital model before a corresponding estimate of the satellite’s position is made. Implementation in a mobile device may involve the use of correction data in the same way as conventional DGPS corrections are used. However, the calculation of the correction values for the pseudorange for each satellite depends on the correction model.

The model that is used to calculate the correction data can be, for example, some high-degree polynomial, for example, 2nd or 3rd order, piecewise continuous polynomial, or even more complex model.

It should be clear that the proposed calculation of the correction data can be used in each of the aspects of the present invention: the first, second and third.

Any of the network elements according to the first, second and third aspects of the present invention may be, for example, a network server or a base station of a communication system. The communication system in the first, second and third aspect of the present invention may be, for example, a cellular communication system, for example a GSM network, a WCDMA network, a CDMA network, etc., but equally a non-cellular communication network, for example a WLAN network, a Bluetooth network ™, WiMax network, etc. Mobile devices in the first, second and third aspect of the present invention may include a mobile communication device such as a mobile phone in which a satellite signal receiver is integrated. Alternatively, the satellite signal receiver may be an additional device with respect to the mobile communication device.

It should be understood that all of the details described for the first aspect of the present invention can also be combined with embodiments of the present invention according to the second aspect of the invention and vice versa.

BRIEF DESCRIPTION OF THE DRAWINGS

Other objects and features of the present invention will become apparent from the following detailed description thereof with reference to the accompanying drawings.

Figure 1 shows a block diagram of a system supporting A-GNSS; and

figure 2 shows a sequence of operations explaining the operation of the system depicted in figure 1.

DETAILED DESCRIPTION OF THE INVENTION

Figure 1 shows a block diagram of a system supporting A-GNSS, according to a variant implementation of the present invention. There is no need to supply GNSS time as auxiliary data in the system, and auxiliary data delivery is used.

The system includes a base station 10 and a network server 20 for a GSM network or any other cellular communication system. The system further includes a first mobile station (MS1) 30, a second mobile station (MS2) 40, GPS satellites 50 (GPS SV) and Galileo satellites 60 (GPS SV).

Base station 10 provides a radio interface for nearby mobile stations 20, 30. It comprises a processing device 11 that is capable of implementing various components of the program code, including a parameter recovery component 12, a reference time replacement component 13, a message composition component 14 and a feedback signal sending component 15.

Access to the network server 20 can be obtained by various base stations 10 of the cellular communication system.

In addition, it is connected to the GPS management server and to the Galileo system management server (not shown). It contains a memory 21 containing a database and a processing device 22 that is capable of executing various components of the program code, including the parameter computing component 23, database update component 24 and position assessment component 25.

The first mobile station 30 is a mobile device that includes a GPS receiver 31. The GPS receiver 31 comprises a capture and tracking component 32, which may be implemented as hardware and / or software. For example, to capture and track signals received from GPS satellites 50, signal measurement tasks, including correlation tasks, can be performed by hardware running software code that is executed by the processing device of the GPS receiver 31.

The mobile station 30 further comprises a cellular “machine” 35 as a component of cellular communication. A cellular machine is a module that contains all the components necessary for normal mobile communication between the mobile phone 30 and the cellular communication system, and which can be expanded with additional functions. For this, the cellular machine 33 is or comprises a data processing device that is capable of executing various implemented program code components. In the present embodiment, these program code components include an application component 36, a message evaluation component 37, and a position estimation component 38. The application implemented by the application component 36 may be any application that requests position information, for example, a navigation application or an application that offers the user of the mobile station 30 specific services at specific locations, etc. It should be understood that, alternatively, the application component 36 and the position estimation component 38 may be implemented by some other processing device, for example, the processing device of the GPS receiver 31.

The second mobile station 40 has a design similar to that of the first mobile station 30, but instead of a GPS receiver, it contains a Galileo receiver configured to receive and track signals received from Galileo satellites 60. Alternatively, the second mobile station 40 may include, for example, a hybrid GPS and Galileo receiver.

Below, with reference to FIG. 2, the determination of position information for the mobile station 30, 40 in the system of FIG. 1 is described. Figure 2 shows the sequence of operations, which on the left illustrates the operation of one of the mobile stations 30, 40, in the middle - the operation of the base station 10, and on the right - the operation of the network server 20.

The network server 20, at equal intervals, receives the GPS ephemeris and almanac parameters from the GPS control server for all available GPS satellites 50 and the corresponding Galileo system parameters from the Galileo control server for all available satellites 60 of the Galileo system. GPS parameters comply with the GPS ICD standard and, therefore, belong to the GPS-specific orbital model of the ephemeris and almanac, respectively. The Galileo parameters correspond to the ICD Galileo standard and, thus, belong to the orbital model specific to the Galileo system. Network server 20 may also receive additional information from the GPS control server, from the Galileo control server, or from another object. Such another object can provide, for example, EGNOS and WAAS corrections, which are transmitted by the geostationary EGNOS and WAAS satellites.

The parameter calculation component 23 converts the received GPS parameters to the parameters of the common orbital model (step 201). He then converts the accepted Galileo parameters to the parameters of the same general orbital model. A satellite for which the relevant parameters are valid can be identified, for example, using indices containing not only the PRN, but also the group identifier. The general orbital model is the technical requirements that describe the orbital parameters and algorithms for calculating position information, such as coordinates, speed and acceleration for GPS and Galileo satellites and, possibly, also for satellites of any other GNSS system, for example GLONASS, EGNOS and / or WAAS. In addition, a common orbital model allows the calculation of corrections for satellite signals due to clock drift. It should be noted that any correction data, including correction data for WAAS, EGNOS and / or DGPS, can be calculated or re-calculated specifically for the common orbital model used.

By converting the parameters, the parameters of different GNSS systems are unified, that is, the number of parameters and the word length in the parameters become the same for GPS, Galileo, etc. In addition, the parameters of the general orbital model can be valid for a longer period of time than the parameters of the GPS ephemeris. In addition, they can determine the position of satellites more accurately than, for example, the orbital models of the GPS almanac. This can be achieved, for example, by using more parameters or by using longer word lengths than are determined for parameters transmitted by satellites. Thus, a common orbital model can also be the only orbital model, for example, for GPS. It should be understood that parameter conversion also includes parameter conversion.

The generated parameters of the common orbital model for the corresponding satellite include a reference value that is the reference time for the included information, which is based on the system time of the GNSS system to which the satellite belongs, as well as TOA data for GPS ephemeris data or TOA data for GPS almanac. For example, for a GPS satellite, the reference time is based on the calculation of the time of the week (TOW) for GPS, such as TOE or TOA.

Now, the application component 36 of the mobile station 30, 40 may need some position information. To obtain the required information, he can request auxiliary data for the GPS and / or Galileo system from the cellular communication system (step 301). The request for ancillary data indicates the type of GNSS that is supported by the mobile station 30, 40.

When the base station 10 receives the request for auxiliary data, the parameter recovery component 12 instructs the network server 20 to provide the parameters of the common orbital model for those satellites 50, 60 from supported GNSS systems that are currently visible from the location of the base station 10 (step 101) . The instructions include identification of the base station 10 and identification of the GNSS system or systems.

Then, the network server 20 parameter computing component 23 determines the satellites 50, 60 that are currently visible from the location of the base station 10 and which belong to the identified GNSS system or systems (step 202). The current position of the satellites can be determined using the generated parameters of the orbital model. Thus, the satellites that are currently visible to the identified base station 10 can be easily determined if the association between the corresponding identification of all base stations and their location is stored in the network server 20, for example, in a database in memory 21. The parameter calculation component 23 selects the parameters of the orbital model for the currently visible satellites and provides them to the base station 10, possibly together with additional information. Such additional information may include, for example, correction for DGPS and RTK, correction for EGNOS and / or WAAS, short-term differential corrections, warnings regarding short-term integrity, and carrier phase measurements. After a special request by the mobile station 30, 40 transmitted by the base station 10, the additional information may also contain data bits to erase the data.

The parameter recovery component 12 of the base station 10 receives the information provided and transfers it to the reference time replacement component 14.

The reference time replacement component 13 of the base station 10 replaces the GNSS based base time in the parameters of the orbital model for each visible satellite 50, 60 with the reference time based on the cellular communication system (step 102). If the cellular communication system is a GSM network, the reference time based on the cellular communication system may include, for example, a group of frame number, time slot and bit number {FN, TS, BN} [FN, frame number; TS, time slot; BN, bit number], which represents time in a GNSS-based reference time system. In the case where the cellular communication system is a WCDMA network, the reference time based on the cellular communication system may include, for example, a system frame number (SFN), a slot and a chip that represent time in a GNSS based reference time system.

In order to be able to replace the GNSS-based reference time with the cellular-based reference time, base station 10 must be aware of the current relationship between GNSS time and system time of the cellular communication system. There are several options for providing the base station 10 with such a ratio, since the requirements for the accuracy of the ratio are not very strict. It is enough to have a ratio with an accuracy of 10-100 μs or even with an accuracy of 1 ms. The satellite moves at a speed of approximately 3.8 km / s, and thus the error in the satellite position for 1 ms corresponds to at most 4 m, which is insignificant.

In the first embodiment, the location measurement unit (LMU) is connected to the base station 10. In this case, the LMU can determine the GNSS time and provides it to the base station 10. Then, the base station 10 can determine the ratio itself. However, it should be noted that it would be quite expensive to provide all the base stations of the network with their own LMU.

In the second embodiment, there is only one available LMU in the cellular communication system, and time differences for all base stations 10 are measured by the cellular communication system at the location of this LMU. For example, a single base station in a network can be equipped with an LMU to calculate the relationship between GNSS time and cellular system time. The time differences between the base station equipped with the LMU and all other base stations 10 are measured to calculate the ratio of the GNSS time and the cellular system time for any base station 10 in the cellular system. Time differences can be measured, for example, by capturing and evaluating measurements of the difference in observed times (OTD), issued by default from mobile stations 30, 40 to the cellular communication system.

In the third embodiment, the cellular communication system also has only one available LMU, and time differences are measured in a matrix solution. In this embodiment, mobile stations 30, 40 are used to measure a time difference with a base station based on observed time difference (OTD) measurements. For example, Cambridge Positioning Systems Ltd (CPS) has proposed a method for locating and storing time using the approach described above. This method includes a more specific measurement of the time difference for the base station in the mobile station, the management of the corresponding database in the mobile station, and the use of this database to determine the location and storage of GPS time. The method is called advanced GPS (E-GPS, Enhanced-GPS). Using the E-GPS method allows the cellular communication system to also obtain the time differences in the cellular communication system between the base station with the LMU and other base stations 10, if the time differences determined in the mobile stations 30, 40 are output to the cellular communication system.

In a fourth embodiment, no LMU is required in a cellular communication system. Instead, the mobile station 30, 40 itself provides a correlation between the GNSS time and the cellular system time. If the mobile station 30, 40 already has a valid relationship from either a previous location communication session or an E-GPS solution, this information can be transmitted to the cellular communication system along with a request for ancillary data. Some options for obtaining and storing valid time ratios in the mobile station 30, 40 will be described below in step 306. Then, the base station 10 can use the time ratio provided by the mobile station 30, 40 to calculate the reference time based on the cellular communication system for the parameters orbital model.

The relationship of GNSS time to cellular system time has also been described in US Pat. Nos. 6678510 B2 and No. 674820262, which are incorporated herein by reference.

As soon as the GNSS-based reference time in the parameters of the orbital model for each visible satellite 50, 60 of the supported GNSS is replaced by the time based on the corresponding cellular communication system, the message composing component 14 composes a message for each of these satellites 50, 60 (step 103). The message is the same for any location mode. The message includes an information element (IE, Information Element) with the parameters of the orbital model, including the replaced reference time. In addition, it may include a reference position, namely, the known position of the base station 10. Further, it may include any information provided by the network server 20, information provided by some other entity, or information generated in the base station 10 itself.

Messages are then transmitted to the requesting mobile station 30, 40.

It should be noted that, alternatively, the base station 10 can collect such messages at equal time intervals for all visible satellites 50, 60 and broadcast messages to all mobile stations 30, 40 located in the cell that is served by the base station 10.

The message evaluation component 37 in the mobile station 30, 40 receives the messages and decodes the frame number, time slot and bit number, determining the time of the cellular communication system. He then extracts the information included in the received messages (step 302). The time indication of the cellular communication system, possibly relative to local time, and the extracted information, including the parameters of the orbital model, are transmitted to the position estimation component 38.

The position estimation component 38 knows the algorithms of the general orbital model. Based on these algorithms, the position estimation component 38 extrapolates the corresponding satellite trajectory as a function of the current time of the cellular communication system using the provided parameters of the orbital model and, possibly, taking into account short-term differential corrections, etc. (step 303). Based on the acquired satellite path, the position estimation component 38 may limit the possible satellite propagation time and Doppler frequency in a conventional manner. Given the known limits of propagation time and Doppler frequency, it is also possible to limit the possible phases of the codes to be checked. Such restrictions on the phases of the codes are fulfilled for all satellites for which the parameters of the orbital model were provided, with the exception of those for which, in addition, an operational warning about the integrity of the parameters was issued. An operational warning about the integrity of the parameters can be issued by the network server 20 through the base station 10 whenever there is a sudden satellite failure.

The position estimation component 38 transmits certain code phase restrictions and possibly additional information included in the received messages to the capture and tracking component 32. Capture and tracking component 32 collects data about visible satellites (step 304). This information is used in the usual way to accelerate the capture of satellite signals by limiting the search options. The capture and tracking component 32 may also be responsible for decoding the navigation data in the received satellite signals. Capture and tracking component 32 provides measurement results, including any decoded navigation data, to position estimation component 38.

Now, the position estimation component 38 can determine the position of the mobile station 30, 40 in a conventional manner (step 305). Thus, it determines the pseudorange for those satellites 50, 60 from which the signals were received. In addition, it determines the exact position of the satellites based on decoded navigation data during signal transmission, and this position is contained in the decoded navigation data and refined by the measurement results. The position estimation component 38 then uses the pseudorange along with the determined satellite position to estimate the position of the mobile station. The position estimation component 38 may equally conventionally determine any other desired position information, such as speed, GNSS time, measurement and position uncertainties, etc. Certain position information may then be provided to the application component 36 for intended use.

By default, the position estimation component 38 in the mobile station 10 provides certain position information, received measurement results, and the relationship between the time of the cellular communication system and the GNSS time as feedback data to the cellular communication system. The feedback data is the same regardless of the location mode used, except that the position of the mobile station 10 can only be set if it is determined by the mobile station 10. The feedback data is transmitted by the feedback signal sending component 15 from the base station 10 to the network server 20 (step 104).

The database update component 24 in the network server 20 can collect position information, the relationship between the time of the cellular communication system and the GNSS time, and in addition, OTD measurements to create and update the database 21 from the time differences between different base stations (step 203). This database 21 can be used to provide accurate time auxiliary data to mobile stations 30, 40 to increase sensitivity without providing GNSS time per se.

The location computing component 25 in the network server 20 may use the measurement results in the feedback data, if any, to estimate the position of the mobile station 30, 40 in the event that the mobile station 30, 40 itself is not able to calculate the position (step 204).

Mobile station 30, 40 may also store a default relationship between cellular system time and GNSS time (step 306). This can be done if the mobile station 30, 40 received the actual GNSS location and was able to relate the current time of the cellular communication system, for example, in terms of a frame, subframe, slot, bit and chip, to GNSS time or to accept the initial ratio in the form of auxiliary data. In this case, the mobile station 30, 40 can reconstruct or restore the GNSS time at any time only by estimating the time elapsed from the last GNSS location using the time of the cellular communication system and under the assumption that the mobile station 30, 40 has not moved from one cell to another one. If the mobile station 30, 40 has moved from one cell to another, the relationship between GNSS time and cellular system time must be regenerated based on the new GNSS location. Alternatively, the existing ratio may be updated to take into account the time difference between the base station serving the previous cell and the base station serving the current cell. The time difference can be obtained using the auxiliary data of the OTD network under the assumption that there is an available database of time differences. In addition, the time difference can be obtained from the OTD measurements, which the terminal performs independently. In addition, the time difference can be obtained from the difference of the measured times of movement forward and / or back and forth in the previous and current cell.

In addition, alternatively, the time ratio can be obtained, for example, using GPS time from a cellular communication system. For example, in CDMA networks, GPS time is available by default.

If the mobile station 30, 40 has a valid time ratio for the GNSS system - a cellular communication system, this ratio can be used to improve performance in terms of "time for first adjustment" and sensitivity. For such an improvement in performance, the time ratio for the GNSS system, a cellular communication system with hundreds of microsecond accuracy, is quite sufficient.

The mobile station 30, 40 may return the results of the OTD measurements to the cellular communication system with each request for ancillary data (step 301). It can return OTD measurement results, for example, in seconds, in particular in microseconds or nanoseconds, instead of frame or subframe differences, making the information time-independent of the cellular communication system.

It should be noted that the described embodiment of the present invention is only one of a variety of possible embodiments of the present invention. For example, instead of GPS and / or Galileo systems, you can support another or additional GNSS system. As mentioned above, instead of a GSM network, you can also use any other type of cellular communication system. In addition, some processing can be enabled between different elements. For example, a reference time change may equally be performed centrally in a network server for all base stations. In addition, the information provided may vary. In addition, instead of the new orbital model for GPS satellites, as well as for other GNSS satellites, you can use the well-known GPS ephemeris models and / or orbital GPS almanac models. In addition, one or more orbital models standardized for another specific GNSS system may be used. In addition, a reference time change is not required when GNSS time is readily available in mobile stations, etc.

Claims (17)

1. A method of supporting satellite positioning of a mobile device using auxiliary data, including in the specified mobile device:
receiving from the communication system the specified auxiliary data, including the parameters of the orbital model that describes the movement of the corresponding satellite of a particular satellite positioning system, while these parameters have a format that differs from the format of the parameters of the orbital model specified for the specified satellite positioning system, or were obtained from a source other than satellite broadcast data;
receiving differential corrections for said received parameters of said orbital model; and
correction of the indicated received parameters of the orbital model based on the indicated differential corrections. 2. The method according to claim 1, in which the specified orbital model for which the parameters are accepted is more accurate than the specified orbital model specified for the specified satellite positioning system. 3. The method according to claim 1, further comprising evaluating the position of said satellite by said mobile device based on the received parameters of said orbital model. 4. The method according to claim 1, further comprising assessing the position of the specified mobile device in the specified mobile device using the accepted parameters of the specified orbital model. 5. A method of supporting satellite-based positioning of a mobile device using auxiliary data, including: obtaining in the communication system the parameters of the orbital model describing the movement of the corresponding satellite of a particular satellite-based positioning system, and these received parameters have a format that differs from the format of the parameters of the orbital model specified for the specified satellite positioning system, or obtained from a source different from the data from satellite broadcasting; and
transmitting these received parameters and differential corrections for these received parameters as part of the auxiliary data for said satellite positioning to at least one mobile device, wherein said differential corrections allow the mobile device to correct said parameters. 6. The method according to claim 5, in which the specified orbital model for which the parameters are obtained is more accurate than the specified orbital model specified for the specified satellite positioning system. 7. The method according to claim 5, further comprising providing corrective data for said orbital model, for which parameters were obtained, to said at least one mobile device. 8. The method according to claim 5, further comprising assessing in the specified communication system the location of the mobile device to which the specified received parameters are issued, using feedback from the specified mobile device. 9. The method according to claim 5, in which said auxiliary data is transmitted to a specific mobile device after being requested by said mobile device. 10. A device that supports satellite positioning using auxiliary data and containing:
a communication component configured to receive auxiliary data from the communication system, including the parameters of the orbital model describing the movement of the corresponding satellite of a particular satellite positioning system, and differential corrections for the specified parameters of the orbital model, while these parameters have a format that differs from the format of the parameters of the orbital models specified for the specified satellite positioning system, or were obtained from a source distinguishing from satellite data, and
a processing unit configured to correct said received parameters of the orbital model based on said differential corrections. 11. The device of claim 10, wherein said communication component is further adapted to receive correction data for said received parameters of the orbital model, said device comprising a processing component configured to correct said received parameters of said orbital model based on said correction data. 12. The device of claim 10, containing a processing component configured to estimate the location of the specified device using the received parameters of the specified orbital model. 13. A device for supporting satellite positioning of a mobile device using auxiliary data, comprising a processing component configured to obtain parameters of an orbital model describing the movement of the corresponding satellite of a particular satellite positioning system, wherein said received parameters have a format that differs from the parameter format the orbital model specified for the specified satellite positioning system, or obtained from a source other than the satellite broadcast data; and configured to provide said received parameters and differential corrections for said received parameters as part of the auxiliary data for said satellite positioning of at least one mobile device, said differential corrections allowing the mobile device to correct said parameters. 14. The device according to item 13, in which the specified processing component is additionally configured to provide corrective data for the specified orbital model, for which the parameters are received, in the specified at least one mobile device. 15. The device according to item 13, in which the specified processing component is additionally configured to evaluate the position of the mobile device for which the obtained parameters are provided, using feedback from the specified mobile device. 16. A device for supporting satellite positioning of a mobile device using auxiliary data, comprising:
means for receiving auxiliary data from the communication system, including the parameters of the orbital model describing the movement of the corresponding satellite of a particular satellite positioning system, and for receiving differential corrections for the specified received parameters of the orbital model, and these parameters have a format that differs from the format of the parameters of the orbital model, set for the specified satellite positioning system, or were obtained from a different source than the data from tnikovoy broadcast; and
means for correcting said received parameters of the orbital model based on said differential corrections. 17. A device for supporting satellite positioning of a mobile device using auxiliary data, including means for implementing the method according to claim 5.

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