53results about How to "Reduce time to first fix" patented technology

The invention relates to an auxiliary satellite navigation system and a global positioning system (GPS) receiver, in particular to a high-sensitivity navigation receiver mainly used indoors as well as an indoor positioning GPS receiver and an auxiliary satellite navigation positioning system adopting high-sensitivity satellite navigation positioning technology. The system at least comprises a terminal receiver, a reference receiver, a positioning server and a communication network; all devices are combined into an integral indoor positioning system; the entire system is divided into a high-sensitivity satellite navigation receiver and a network auxiliary system. Through adopting the positioning mode in which point positioning under weak signal condition is combined with continuous positioning under strong signal condition, the method mainly solves related technical problems such as the organic combination of integral hardware implementation. The invention has the advantages that: the system and the method improve the sensitivity index of a terminal user and reduce first positioning time; moreover, the designed navigation receiver can process indoor weak satellite signal, etc.

A navigation system includes a cellular phone, a base station and a network server. Each of them is paired with a GPS receiver. Cell phone GPS receivers are aided by information received from base stations and web servers, reducing the uncertainty of satellite searches. Time difference and / or frequency difference measurements are used with the collected data, and the cell phone and its GPS receiver assume they are precise time and frequency. The correction information is used to post-process the velocity solution computed by the cell phone to obtain a more accurate solution for the system.

The embodiment of the invention provides a method and a device for achieving bit synchronization and frame synchronization of a text of a receiver. Aiming at a 500 bps text in a navigation digital receiver, the method mainly comprises the following steps: adding two adjacent 1 ms accumulated values in the text with a set time length in turn, and acquiring a text after the bit synchronization according to the accumulated value after the addition; and searching a trellis code frame header in the text after the bit synchronization according to the scheduled format information, and finishing the synchronization of the text for the bit synchronization to be determined according to the searched trellis code frame header. The method and the device can improve the speed of the bit synchronizationand the frame synchronization of navigation texts of 500 bps and 50 bps in the navigation digital receiver, save system resources, and improve the system reliability. Besides, the method and the device achieves the bit synchronization and the frame synchronization in an FPGA (Field Programmable Gate Array), and can generate the satellite launch time more quickly and shorten the first-time positioning time of the navigation digital receiver.

The invention relates to a GPS / GALILEO navigation base band processing chip and a navigation receiver, belonging to the technical field of receiver of global satellite locating system. The navigation base band processing chip comprises a capturing engine, a tracking passage, a built-in processor and an interface control logic; and the built-in processor consists of a control logic, a built-in processor core, a digital operation module and a double-mouth RAM. The navigation base band processing chip works together with an external master control microprocessor, and calculates the user location according to the satellite trail parameter provided for the master control microprocessor and the information such as pseudo-range measurement; the master control microprocessor interacts with the navigation base band processing chip through a double-mouth RAM (Random Access Memory); a control logic circuit can cut off the clock or voltage of the idle circuit in the navigation base band processing chip so that the power consumption of the navigation base band are greatly reduced; simultaneously, the interface of the navigation base band processing chip and the master control microprocessor has the advantages of flexibility, convenience, strong expandability, and the like.

The invention provides a method for calculating the code phase pseudorange between a locating terminal and a satellite in an A-GPS. An A-GPS locating terminal captures the distance measuring signals of satellite and gets the measuring information according to the assistant information received from the network rapidly; an A-GPS algoritic module makes use of the initial position provided by the A-GPS locating terminal and the satellite navigation teletext information provided by the other locating devices to work out the pseudorange from the initial position to the satellite; then the A-GPS algoritic module makes use of the measuring information of terminal to work out the corrected range between the initial position and the actual terminal position; and then the actual pseudorange between the A-GPS locating terminal and the satellite is further worked out. The method inherits the method that the traditional GPS locating system conducts the location through code phase pseudorange; the locating process that the A-GPS locating terminal does not need to download directly, the satellite navigation teletext is obtained indirectly through a network, and the A-GPS locating terminal completes the fast capture of the satellite signals and calculation of the pseudorange information is realized.

The invention provides a quick locating method based on GEO constellation coarse location for a Beidou receiver by use of the characteristic that the GEO satellite in the hybrid constellation of the Beidou system is high in message rate, and solves the problem that when the outline coordinates of a receiver are unknown, the millisecond recovery algorithm for the traditional GNSS signal transmitting time cannot be applied due to a leap of calculated quantity. When the outline coordinates of the receiver are completely unknown, the GEO satellite of which the signal transmitting time is completely acquired is used at first for coarse location, then the millisecond integer time of the sending time of a non-GEO satellite is recovered according to the outline coordinates acquired by coarse location, and finally, all the visible satellites are utilized for accurate location. The quick locating method can achieve millisecond recovery of the non-GEO satellites which finish capture when the Beidou system only finishes frame alignment of GEO constellation, so that the time to first-time location of the receiver when the satellite ephemeris is known is earlier.

The invention relates to a capturing method of a satellite navigation signal in an adjustable carrier wave doppler frequency searching range. The method comprises the following steps that: an initial carrier wave doppler covering range and a corresponded carrier frequency is generated; code phase searching is completed under the carrier wave frequency to obtain a corresponded capturing result; because the covering of the initial carrier wave doppler is complete, search frequency point information of the carrier wave doppler that is frequency hopping information is written into a frequency hopping information memory to complete storage of the frequency hopping information that can be used for subsequent continuous capturing; and other unresearched satellites are switched for continuous execution. According to the invention, searching of an undetermined range of a carrier wave frequency can be completed at the expense of few hardware costs and a fast speed; satellites can be searched ina short time as much as possible; and first positioning time of a receiver is improved.

The invention discloses a method for calibrating GPS standard time in a TD-SCDMA wireless communication system, which comprises the following steps: firstly, obtaining base station GPS standard time by a mobile terminal which needs positioning, then, obtaining signal round trip time from a base station by a wireless network controller, obtaining receiving and sending time differences from the mobile terminal, calculating signal transmission delay according the time differences, then, sending the signal transmission delay to a corresponding mobile terminal by the wireless network controller, and calculating terminal GPS standard time according to the GPS standard time and the signal transmission delay of the base station by the mobile terminal. More accurate GPS standard time can be obtained on the mobile terminal through transferring measured base station signal transmission delay and calibrating base station side GPS standard time which is obtained by the mobile terminal, thereby the receiving sensibility of an A-GPS receiver in a terminal device can be effectively improved, and the first positioning time can be reduced.

A global navigation satellite system (GNSS) receiver system includes a first mobile GNSS receiver and a second mobile GNSS receiver. The first mobile GNSS receiver includes: a first receiver logic for receiving satellite signals and determining positioning related information according to the satellite signals; a data provider logic for providing at least an assisted data according to the positioning related information; and a first communication interface for outputting the assisted data. The second mobile GNSS receiver includes a second communication interface, for communicating with the first communication interface to receive the assisted data from the communication interface; a data collector logic for collecting assisted information from the assisted data; and a second receiver logic for determining positioning information of the second mobile GNSS receiver according to the assisted information and satellite signals.

The invention provides a GNSS text demodulation method suitable for the navigation field. The method comprises that a main tracking channel and N auxiliary tracking channels are started after that a satellite is captured successfully; bit synchronization of the main tracking channel is controlled, one auxiliary tracking channel starts text demodulation, and the other N-1 auxiliary tracking channels start text demodulation successively by being delayed at preset time intervals; frame synchronization is carried out on navigation bit data streams obtained by the N auxiliary tracking channels; after successful bit synchronization of the main tracking channel, text demodulation of the main tracking channel is controlled; whether frame synchronization of the navigation bit data stream of a random auxiliary tracking channel succeeds is determined, if YES, a navigation bit data stream obtained by the main tracking channel continues collecting ephemeris, and the N auxiliary tracking channels are released; and otherwise, the navigation bit data stream obtained by the main tracking channel is used to carry out frame synchronization and collect ephemeris, and the N auxiliary tracking channelsare released. According to the invention, time of first positioning can be shortened effectively needless of adding too many hardware resources.

A rough position is needed to assist a conventional rough time positioning method. For the condition of an unknown rough position, the space transmission finiteness of navigation signals is utilized, a fuzzy search GPS receiver rough time positioning method based on inter-satellite distance compression is provided to expand the application range of a conventional rough time positioning method, and inter-satellite distance compression is utilized to search for space. The method comprises the steps of: firstly, according to an inter-satellite distance, calculating a maximum pseudo range difference range between satellites; secondly, selecting three satellites in combination with elevation to carry out rough positioning on all fuzzy combined conditions, and according to pseudo range remains of all satellites after the positioning, selecting most reasonable fuzzy combination and positioning results; then according to the rough positioning result, restoring pseudo range fuzzy of all the satellite; and finally, using a five-state time-free positioning technology to estimate the position of a user. According to the invention, the rough time positioning is realized under the condition that the rough position is unknown, and the application range of rough time positioning is expanded.

The invention provides a method for shortening Time To First Fix (TTFF) of a GNSS receiver. The method comprises the following steps: a satellite signal is captured and overall millisecond boundary information of the satellite signal is acquired; coherent integration is carried out on data within adjacent overall millisecond boundaries to obtain a coherent integration value; navigation bit boundaries are determined according to the coherent integration value, and simultaneously the coherent integration symbol is stored; after the bit boundaries are determined, navigation bit conciliation is carried out to obtain the final bit symbol; and satellite ephemeris is collected and positioning computing is finished. By the adoption of the technical scheme, on the basis of relatively low resource consumption and no additional construction cost, the TTFF of the GNSS receiver is effectively shortened, and positioning efficiency of the receiver is raised.

The invention discloses a method of acquiring GPS standard time at terminals of a synchronous communication system and a system, comprising: acquiring absolute GPS standard time of a synchronous system clock by an SDPL positioning platform when determining system frame number; executing SUPL flow to perform positioning operation between the SUPL positioning platform and the mobile terminal, when at the starting moment of exchanging the positioning data, the SUPL positioning platform transmits the GPS standard time to the mobile terminal; computing the current GPS standard time according to the current system frame number and the absolute standard time by the mobile terminal. Due to synchronous characteristics between the base station of the synchronous communication system, the invention acquires correct GPS standard time.

The present invention provides a method and an apparatus for reducing Time To First Fix (TTFF) of a Global Navigation Satellite System (GNSS) receiver, including storing ephemeris information into a non-volatile memory, and utilizing the ephemeris information to determine a GNSS time, in order to reduce the TTFF. An apparatus for reducing TTFF of a GNSS receiver includes a storage module and a processing module coupled to the storage module. The storage module is utilized for storing data, wherein the stored data in the storage module is non-volatile. The processing module stores ephemeris information into the storage module and utilizes the ephemeris information to determine a GNSS time, in order to reduce the TTFF. By means of the method and apparatus, it is possible to reduce the TTFF of the GNSS receiver so as to save cost and be propitious to circumstance protection.

The invention discloses a navigation message synchronization method, receiver and device. The method comprises the following steps: obtaining first synchronization information from the receiver, wherein the first synchronization information is used for synchronizing first navigation messages received from navigation equipment by the receiver; determining the time for sending second navigation messages by the navigation equipment according to the first synchronization information; calculating second synchronization information according to the time for sending the second navigation messages, wherein the second synchronization information is used for synchronizing the second navigation messages. Compared with the prior art, the navigation message synchronization method, receiver and device provided by the invention have the advantages that the navigation messages can be quickly synchronized without matching sub-frame headers, the time to first fix (TTFF) is shortened, and the TTFF performance is improved.

The invention discloses an integrated GPS and GLONAS positioning time service method. The method comprises steps of S1 present hour, minute and second determination; S2, leap second correction; and S3, previous circle overturning. Through the method, after a satellite of two systems is captured, in a resolution process, difference of a GPS and GLONASS system in a navigation message is utilized to realize mutual complementation, depth fusion is carried out, a mode of first resolution and then combination in the prior art is changed, performance of an integrated GPS and GLONAS receiver in the prior art is effectively improved, including reducing the first positioning time, improving time service precision and effectively processing special conditions such as leap second correction and thousand-circle overturning.

The invention discloses a high sensitive quick capturing method for satellite signals. The method comprises the steps of S1, generating a main code FFT sequence, and initializing a Doppler frequency;S2, generating a sampling FFT sequence; S3, after the sampling FFT sequence is conjugated, multiplying by the main code FFT sequence and getting the modulus; S4, conjugating the FFT sequence after being subjected to forward cyclic shift, multiplying by the main code FFT sequence and getting the modulus; S5, conjugating the FFT sequence after being subjected to reverse cyclic shift, multiplying bythe main code FFT sequence and getting the modulus; S6, repeating the steps S3 to S5 for preset times, and accumulating the modulus to acquire an accumulated modulus; S7, reserving the maximum of theaccumulated modulus; S8, when the maximum accumulated modulus is more than a preset threshold, conducting the step S11, an when the maximum accumulated modulus is less than a preset threshold, conducting the step S9; S9, moving the Doppler frequency in a stepping manner, and repeating the steps S3 to S8; S10, moving the initial position of satellite data, and repeating the steps S2 to S9; and S11,outputting a result. According to the method, the capturing speed of the satellite signal is improved, the first positioning time is reduced, and the probability of error tracking is reduced.

Provided are a method and an apparatus for updating conversion information parameters, used for updating a set of conversion information parameters applicable to the global satellite navigation system. The method for updating the conversion information parameters comprises the steps of obtaining at least one piece of satellite navigation information via one satellite and updating the conversion information parameters according to the obtained satellite navigation information. The method and apparatus of the invention can prolong the operating lifetime of the set of conversion information parameters and generate better satellite orbit forecasting result, thereby effectively shortening initial positioning time and improving the positioning precision.

The invention discloses a method for obtaining and conveying a GPS standard time in a TD-SCDMA radio communication system, which comprises the following steps: firstly, respectively receiving GPS satellite signals by each of TD-SCDMA base stations, obtaining the absolute GPS standard time when a TD-SCDMA system clock determines a system frame number, then respectively reporting the measured absolute GPS standard time to a radio network controller, memorizing the absolute GPS standard time which is reported by each base station and informing the absolute GPS standard time when the system clockof a community where the mobile terminal which needs to be positioned is positioned in determines the system frame number by the radio network controller, and then calculating the current standard GPS time according to the current frame number by the mobile terminal. The method utilizes the characteristics of the base stations of the TD-SCDMA radio communication system that the base stations are synchronized, the positions of the base stations are accurate, and each of the base stations has a GPS receiver with high accuracy, and the method can obtain more accurate GPS standard time.

An electronic device includes: a satellite signal receiving section that receives a satellite signal with which positioning information is overlapped from a positioning satellite; a reception control section that controls driving of the satellite signal receiving section; and a detecting section that detects a state change of the electronic device, in which the reception control section allows the satellite signal receiving section to enter a driving state when the detecting section detects the state change to receive the satellite signal. According to this electronic device, it is possible to reduce a TTFF at the positioning start, and to reduce power consumption in the satellite signal reception.

A navigation system comprises a cell-phone, a base cellular telephone site, and a webserver. Each is paired with a GPS receiver. The GPS receiver associated with the cell-phone is aided with information received from the cell-site and webserver that help reduce satellite search uncertainty. Time difference and / or frequency difference measurements are taken with data collected from what the cell-phone and its GPS receiver assume to be accurate time and frequency. Correction information is used in post-processing of the velocity solutions computed by the cell-phone to arrive at more precise determinations for the system.

The invention provides a quick locating method based on GEO constellation coarse location for a Beidou receiver by use of the characteristic that the GEO satellite in the hybrid constellation of the Beidou system is high in message rate, and solves the problem that when the outline coordinates of a receiver are unknown, the millisecond recovery algorithm for the traditional GNSS signal transmitting time cannot be applied due to a leap of calculated quantity. When the outline coordinates of the receiver are completely unknown, the GEO satellite of which the signal transmitting time is completely acquired is used at first for coarse location, then the millisecond integer time of the sending time of a non-GEO satellite is recovered according to the outline coordinates acquired by coarse location, and finally, all the visible satellites are utilized for accurate location. The quick locating method can achieve millisecond recovery of the non-GEO satellites which finish capture when the Beidou system only finishes frame alignment of GEO constellation, so that the time to first-time location of the receiver when the satellite ephemeris is known is earlier.

The invention discloses a method for broadcasting and receiving satellite navigation information by multiple rates and belongs to the field of satellite navigation systems. By the method, broadcast information is broadcasted in a way of multiple rates. An information rate is inconsistent with a symbol rate, so that the broadcast information is processed at the sending end in a way of copying or expanding of convolution to make the broadcast information broadcasted at the symbol rate. The broadcast information is recovered at the receiving end in a condensing way so as to restore the original broadcast information. Subframe information is broadcasted in a way of multiple rates so as to improve information broadcasting flexibility and reduce first positioning time at a low rate.

The invention discloses an assistant location method and system based on an SUPL platform. The assistant location method comprises the steps that location assistant information is requested by an access point (AP) to a position server according to preset duration of intervals, and the location assistant information sent by the position server is received and stored according to received time; when cold boot initial boot information of a receiver sent by a user side receiver is received by the AP, and location assistant information received at the last time is coded and then transmitted to the user side receiver; location is conducted by the user side receiver according to the obtained location assistant information. According to the technical scheme, a first-time location time conducted by the receiver through cold boot is shortened, and meanwhile the tracking sensitivity of the receiver under a weak signal environment is improved.

The invention belongs to the technical field of satellite navigation, and discloses an inter-symbol difference and code parallel GPS weak signal capturing method and system. Comprising a digital down-conversion module, a code merging module, a data storage module, a Doppler stripping module, a data folding module, a step-by-step matching coherence module, an inter-symbol difference module, a Doppler compensation module, a step-by-step coherence module, a step-by-step incoherence module, a peak value judgment module, a Purler search completion judgment module, a Doppler regulation and control module and a result output module. According to the high-orbit GPS signal capturing method based on inter-symbol difference and code parallelism, a rapid and efficient capturing algorithm is provided for a navigation receiver; an inter-symbol difference algorithm is adopted to avoid the influence of navigation data jump on the coherent integration duration, and the capture sensitivity of the GPS signal is improved by improving the coherent integration duration. According to the invention, a step-by-step coherent algorithm and a step-by-step incoherent algorithm are adopted, so that rapid acquisition of signals with different intensities is realized, and the first positioning time of a navigation receiver is shortened.

The invention discloses a satellite navigation receiver and a method for locating by utilizing the satellite navigation receiver. The satellite navigation receiver comprises a counter and a control unit, wherein the counter is driven by a reference clock signal having a reference clock frequency. The control unit calculates a correction value indicative of a corrected reference clock frequency by comparing an increment of the counter values during a time period with an increment of the navigation system time during the time period before the satellite navigation receiver is turned off and then the control unit generates a calculated navigation system time according to the correction value before the satellite navigation receiver is started again. By using the satellite navigation receiver and the method for locating by utilizing the satellite navigation receiver of the invention, the first locating time can be effectively shortened.

The invention provides a satellite ephemeris forwarding method. The satellite ephemeris forwarding method comprises the following steps of: setting parameter information, comprising framing information and an ephemeris forwarding mode, of a satellite ephemeris forwarding system; carrying out self-positioning and acquiring local time and position information of the satellite ephemeris forwarding system; selecting an ephemeris forwarding working mode and capturing and tracking a satellite signal emitted by an outdoor visible satellite or a satellite signal simulator; analyzing the satellite signal to obtain corresponding satellite ephemeris information; judging the validity of the satellite ephemeris information, retaining the valid satellite ephemeris information, and eliminating the invalid satellite ephemeris information; framing the valid satellite ephemeris information according to the framing information; and selecting an ephemeris forwarding mode, forwarding the framed valid satellite ephemeris information to an external receiver, and displaying the system state of the satellite ephemeris forwarding system. According to the invention, the designed satellite ephemeris forwarding system is used for acquiring a satellite real-time signal and forwarding the analyzed valid ephemeris information to the external receiver, so that the first positioning time is shortened, and rapid positioning is realized.

The invention discloses a method and device for realizing capture preprocessing, and the method comprises the steps: estimating and determining a visible satellite of a navigation receiver within a preset duration according to the satellite visible associated information of the navigation receiver; and performing capture processing according to the visible satellite of the navigation receiver within the pre-estimated and determined preset duration. According to the embodiment of the invention, the number of searched satellites during cold start is reduced, the cold start first-time positioning time is shortened, and the capture efficiency of the navigation receiver is improved.

The invention provides a spaceborne auxiliary GPS method based on dynamic orbit extrapolation. The spaceborne auxiliary GPS method comprises the steps that 1) orbit position extrapolation is performed according to a low-earth-orbit satellite dynamic model and the latest positioning result of a spaceborne GPS receiver under a J2000.0 coordinate system so that the extrapolation position of the spaceborne GPS receiver is acquired and converted to an ECEF coordinate system; 2) the positions of all GPS satellites under the ECEF coordinate system are acquired according to effective GPS ephemeris calculation; 3) the pitch angle of all the GPS satellites to the spaceborne GPS receiver at the same epoch time is calculated, whether each GPS satellite is visible to the spaceborne GPS receiver is judged, all the GPS satellites are ranked according to the probability of visibility, and a GPS satellite PRN number list after ranking is acquired; and 4) GPS satellite priority configuration is performed on the capture channel of the spaceborne GPS receiver according to the GPS satellite PRN number list. The number of times of capturing and searching of the spaceborne GPS receiver is reduced so that positioning speed is enhanced.

The invention relates to a capturing method of a satellite navigation signal in an adjustable carrier wave doppler frequency searching range. The method comprises the following steps that: an initial carrier wave doppler covering range and a corresponded carrier frequency is generated; code phase searching is completed under the carrier wave frequency to obtain a corresponded capturing result; because the covering of the initial carrier wave doppler is complete, search frequency point information of the carrier wave doppler that is frequency hopping information is written into a frequency hopping information memory to complete storage of the frequency hopping information that can be used for subsequent continuous capturing; and other unresearched satellites are switched for continuous execution. According to the invention, searching of an undetermined range of a carrier wave frequency can be completed at the expense of few hardware costs and a fast speed; satellites can be searched ina short time as much as possible; and first positioning time of a receiver is improved.