Positioning method, positioning chip and terminal device

Abstract

A positioning method and device are provided. The positioning method is applied to a terminal device, the terminal device comprising a positioning chip (130) and a system-on-chip (SoC) chip (120). The positioning method comprises: the positioning chip (130) receives a satellite signal (101) transmitted by at least one satellite, the positioning chip (130) obtains a differential correction value (102) sent by a base station through the SoC chip (120), and the positioning chip (130) performs positioning calculation (103) using the satellite signal and the differential correction value based on carrier phase differential technology. The carrier phase differential technology is an RTK technology. The positioning method provides a new RTK architecture based on the terminal positioning chip (130). The carrier phase differential technology is used to achieve correction of rough positioning results by a mobile phone, so that the positioning accuracy reaches the sub-meter level, further improving the performance of mobile phone positioning and navigation, and meeting user needs.

Description

Technical Field

[0001] The present application relates to the field of satellite positioning technology, and in particular to a positioning method, a positioning chip, and a terminal device. Background Art

[0002] With the advancement of technology, mobile phone positioning and navigation applications have become increasingly widespread, including in-car navigation, Didi taxi-hailing, Electronic Toll Collection (ETC), and virtual mobile games. For in-car navigation, lane-level positioning accuracy is required to prompt vehicles when turning and entering or exiting elevated roads. For taxi-hailing, the user's exact location is essential. These application scenarios place increasingly high demands on the accuracy of mobile phone positioning and navigation.

[0003] For traditional mobile phone positioning technology, the commonly used Figure 1 The chip structure shown, for example, in a global navigation satellite system (GNSS) positioning chip includes: a PVT module, an inertial navigation module, and a capture and tracking module. PVT stands for position, velocity, and time in navigation. The GNSS positioning chip receives satellite signals from the Global Positioning System (GPS), Beidou, the Galileo satellite navigation system, the GLONASS system, and other systems through the mobile phone antenna, captures and tracks the received satellite signals, and generates necessary measurement information such as pseudorange observations for use by the PVT module. The PVT module is mainly used to calculate the position, velocity, and time of the mobile terminal. After the calculation, the position, velocity, and other information are transmitted to the mobile phone's operating system, such as the Apple (iOS) or Android system. In addition, the inertial navigation module can be used to interact with and assist the PVT module with the measurement parameters reported by sensors such as the speedometer and accelerometer, further improving the navigation performance of the mobile phone.

[0004] Current mobile phone positioning solutions use pseudo-range observations output by GNSS positioning chips to achieve positioning. This solution is traditional and relatively simple to implement, but the accuracy is low. The positioning accuracy can only be determined to a granularity of a few meters, which cannot meet the needs of high-precision positioning and navigation. Summary of the Invention

[0005] This application provides a positioning method and device for improving the accuracy of mobile phone positioning to meet user needs. Specifically, the following technical solutions are disclosed:

[0006] In a first aspect, the present application provides a positioning method, which can be applied to a terminal device, which includes a positioning chip and a system-on-chip (SoC) chip. Furthermore, the method includes: the positioning chip receives satellite signals transmitted by at least one satellite, obtains the differential correction amount sent by the base station through the SoC chip, and performs positioning calculations based on the satellite signal and the differential correction amount based on carrier phase difference technology.

[0007] The carrier phase differential technology is an RTK technology, and the positioning chip is a GNSS positioning chip.

[0008] This method proposes a new RTK architecture based on a mobile phone GNSS positioning chip. Through carrier phase differential technology, the terminal device can correct the rough positioning results, achieving sub-meter positioning accuracy, further improving the performance of mobile phone positioning and navigation to meet user needs.

[0009] In conjunction with the first aspect, in a possible implementation of the first aspect, after the positioning chip receives a satellite signal transmitted by at least one satellite, the method further includes: the positioning chip performing synchronous detection on the satellite signal, and after completing the synchronous detection, tracking the satellite signal using a tracking loop to obtain carrier phase tracking information of the satellite signal. Using the satellite signal and the differential correction value to perform positioning calculations includes: the positioning chip performing positioning calculations using the carrier phase tracking information of the satellite signal and the differential correction value to obtain location information of the terminal device. This location information is precise location information. The carrier phase tracking information includes a carrier phase measurement value.

[0010] The received satellite signal includes a first satellite signal and a second satellite signal. Specifically, the first satellite signal is a traditional satellite signal, and the second satellite signal is a modernized satellite signal.

[0011] In conjunction with the first aspect, in another possible implementation of the first aspect, when the satellite signal transmitted by the at least one satellite includes a first satellite signal, the first satellite signal is a traditional satellite signal, and the aforementioned steps of tracking the satellite signal using a tracking loop after completing the synchronization detection to obtain carrier phase tracking information of the satellite signal include:

[0012] After completing the synchronization detection, a determination is made as to whether navigation messages are assisting tracking. If so, the first satellite signal is tracked using the first tracking loop, which includes a four-quadrant phase detector. After passing through the four-quadrant phase detector, the first satellite signal outputs a first carrier phase measurement value. Furthermore, before the positioning chip uses the carrier phase tracking information of the satellite signal and the differential correction value to perform positioning calculations, the positioning chip also determines, based on the first carrier phase measurement value, whether a cycle slip has occurred in the carrier phase. If not, the aforementioned step of performing positioning calculations using the carrier phase tracking information of the satellite signal and the differential correction value is performed.

[0013] This implementation utilizes the principle of differential positioning to perform differential calculations on the carrier phase, compensating for errors in coarse positioning. A four-quadrant phase detector is then used to track satellite signals, expanding the phase detection range and avoiding the limitations of the two-quadrant phase detector's tracking loop, which can lead to 180° of phase ambiguity in the tracking phase and cause the replicated carrier phase to be incorrectly adjusted in the opposite direction. Finally, cycle and half-cycle slip repairs are used to address the cycle and half-cycle slip issues that occur during receiver replication.

[0014] In conjunction with the first aspect, in another possible implementation of the first aspect, the method further includes: after the positioning chip completes the synchronization detection, if there is no navigation message to assist in tracking, tracking the first satellite signal using a second tracking loop, the second tracking loop including a two-quadrant phase detector, and the first satellite signal outputs a second carrier phase measurement value after passing through the two-quadrant phase detector. Furthermore, before the positioning chip performs positioning calculations using the satellite signal's carrier phase tracking information and the differential correction value, the method further includes:

[0015] The positioning chip determines whether a cycle slip occurs in the carrier phase based on the second carrier phase measurement value; if not, the frame header of the navigation message on the demodulated first satellite signal is queried to determine whether it is in phase with the actual navigation message frame header; if it is in phase, the steps of performing positioning calculation using the carrier phase tracking information and differential correction amount of the satellite signal by the aforementioned positioning chip are executed.

[0016] In combination with the first aspect, in another possible implementation of the first aspect, the method also includes: if it is judged that the phase is different from the actual navigation message frame header, the positioning chip performs phase compensation on the second carrier phase measurement value, such as adding 0.5 cycles of phase to compensate, to obtain a third carrier phase measurement value; and the aforementioned steps use the carrier phase tracking information and differential correction amount of the satellite signal to perform positioning calculations, including: using the third carrier phase measurement value and the differential correction amount to perform positioning calculations.

[0017] This implementation records carrier phase tracking information while performing carrier phase tracking, and detects cycle slips to address cycle slips in carrier phase measurements. Furthermore, to correct for half-cycle slips, when a half-cycle slip is detected in a subsequent carrier phase measurement, 0.5 cycles are added to compensate, thus overcoming the 180° phase ambiguity caused by phase loss and resolving the half-cycle slip issue that occurs when positioning chips are replicated.

[0018] In conjunction with the first aspect, in another possible implementation of the first aspect, when the satellite signal transmitted by the at least one satellite includes a second satellite signal, the second satellite signal is a modernized satellite signal. The aforementioned method of tracking the satellite signal using a tracking loop after completing the synchronization detection to obtain carrier phase tracking information of the satellite signal includes: tracking the second satellite signal using a first tracking loop, the first tracking loop including a four-quadrant phase detector, and the second satellite signal outputting a fourth carrier phase measurement value after passing through the four-quadrant phase detector. Furthermore, before the aforementioned positioning chip uses the carrier phase tracking information of the satellite signal and the differential correction value for positioning calculation, the method further includes: determining whether a cycle slip has occurred in the carrier phase based on the fourth carrier phase measurement value; if not, performing a step of performing positioning calculation using the carrier phase tracking information of the satellite signal and the differential correction value.

[0019] This implementation, when tracking and processing modern satellite signals, eliminates the need to determine whether navigation messages are assisting tracking, as is required in traditional satellite signal tracking, as modern satellite signals have both data and pilot channels. Instead, the system processes the pilot channel directly. Once the positioning chip detects that the modern satellite signal has completed bit synchronization, it can directly track the signal using a four-quadrant phase detector to determine the satellite signal's carrier phase measurement.

[0020] In combination with the first aspect, in another possible implementation of the first aspect, after the positioning chip receives a satellite signal transmitted by at least one satellite, the method further includes: the positioning chip demodulates the received satellite signal to obtain coarse position information of the terminal device; and sends the coarse position information to a base station so that the base station feeds back a differential correction amount based on the coarse position information.

[0021] The differential correction includes a carrier phase measurement of a common view satellite signal, where the common view satellite signal is a satellite signal tracked jointly by the terminal device and the reference station. The positioning chip uses the carrier phase tracking information of the satellite signal and the differential correction to perform positioning calculations, including: performing a differential calculation using the carrier phase measurement of the common view satellite signal and a first carrier phase measurement to obtain a first integral ambiguity; determining a corrected carrier phase measurement using the first integral ambiguity; and performing a positioning calculation based on the corrected carrier phase measurement to obtain the terminal device's location information. This location information is accurate.

[0022] This implementation method uses RTK technology to obtain a corrected carrier phase measurement value from the carrier phase measurement value sent by the base station and the first carrier phase measurement value output by the tracking loop of the positioning chip, and uses the corrected carrier phase measurement value to perform positioning calculations, thereby improving the positioning accuracy of the terminal device.

[0023] On the second aspect, the present application also provides a positioning device, such as a positioning chip, which includes: a transceiver circuit and a processing circuit. Furthermore, the transceiver circuit is used to receive satellite signals transmitted by at least one satellite; the processing circuit is used to obtain the differential correction amount sent by the base station through the system-on-chip (SoC) chip, and based on the carrier phase difference technology, use the satellite signal and the differential correction amount to perform positioning calculations.

[0024] In combination with the second aspect, in a possible implementation of the second aspect, the processing circuit is further used to implement the following functions: after the transceiver circuit receives a satellite signal transmitted by at least one satellite, perform synchronization detection on the satellite signal, and after completing the synchronization detection, use the tracking loop to track the satellite signal to obtain carrier phase tracking information of the satellite signal; and use the carrier phase tracking information of the satellite signal and the differential correction amount to perform positioning calculation to obtain the position information of the terminal device.

[0025] In conjunction with the second aspect, in another possible implementation of the second aspect, when the received satellite signal transmitted by at least one satellite includes the first satellite signal, the processing circuit is further configured to implement the following functions:

[0026] After completing the synchronization detection, a determination is made as to whether navigation messages are used to assist tracking. If so, the first satellite signal is tracked using a first tracking loop, wherein the first tracking loop includes a four-quadrant phase detector. After the first satellite signal passes through the four-quadrant phase detector, a first carrier phase measurement value is output. Furthermore, before performing the positioning calculation, a determination is made based on the first carrier phase measurement value as to whether a cycle slip has occurred in the carrier phase. If not, positioning calculation is performed using the carrier phase tracking information of the satellite signal and the differential correction value.

[0027] In conjunction with the second aspect, in another possible implementation of the second aspect, the processing circuit is further configured to implement the following function: after completing the synchronization detection, if there is no navigation message to assist in tracking, tracking the first satellite signal using the second tracking loop. The second tracking loop includes a two-quadrant phase detector, and the first satellite signal outputs a second carrier phase measurement value after passing through the two-quadrant phase detector.

[0028] Before the processing circuit performs positioning calculations, it is determined whether a carrier phase cycle slip occurs based on the second carrier phase measurement value; if not, the frame header of the navigation message on the demodulated first satellite signal is queried to determine whether it is in phase with the actual navigation message frame header; if they are in phase, positioning calculations are performed using the carrier phase tracking information of the satellite signal and the differential correction amount.

[0029] In conjunction with the second aspect, in another possible implementation of the second aspect, the processing circuit is further configured to: determine that the second carrier phase measurement value is out of phase with the actual navigation message frame header, perform phase compensation on the second carrier phase measurement value to obtain a third carrier phase measurement value, and perform positioning calculation using the third carrier phase measurement value and the differential correction amount.

[0030] In combination with the second aspect, in another possible implementation of the second aspect, when the satellite signal transmitted by at least one received satellite includes a second satellite signal, the processing circuit is further used to implement the following function: tracking the second satellite signal using a first tracking loop, wherein the first tracking loop includes a four-quadrant phase detector, and the second satellite signal outputs a fourth carrier phase measurement value after passing through the four-quadrant phase detector.

[0031] Before performing the positioning calculation, it is determined whether a cycle slip occurs in the carrier phase according to the fourth carrier phase measurement value; if not, the positioning calculation is performed using the carrier phase tracking information of the satellite signal and the differential correction amount.

[0032] In combination with the second aspect, in another possible implementation of the second aspect, the processing circuit is also used to implement the following functions: after receiving a satellite signal transmitted by at least one satellite, demodulate the satellite signal to obtain coarse position information of the terminal device; and send the coarse position information to a base station so that the base station feeds back the differential correction amount based on the coarse position information.

[0033] The differential correction includes a carrier phase measurement value of a common view satellite signal, where the common view satellite signal is a satellite signal jointly tracked by the positioning chip and the reference station. The processing circuit is further configured to: perform a differential calculation using the carrier phase measurement value of the common view satellite signal and a first carrier phase measurement value to obtain a first integral ambiguity, determine a corrected carrier phase measurement value using the first integral ambiguity, and perform a positioning calculation based on the corrected carrier phase measurement value to obtain location information of the terminal device.

[0034] In a third aspect, the present application provides a tracking loop, comprising: a control circuit, a four-quadrant phase detector, a phase-locked loop, a loop filter, a voltage-controlled oscillator, and a first switch; wherein one end of the first switch is connected to the control circuit, and the other end is connected to the four-quadrant phase detector; the four-quadrant phase detector is connected to the loop filter and the voltage-controlled oscillator in sequence; in the presence of a navigation message to assist in tracking a satellite signal, the control circuit controls the first switch to close, and tracks the satellite signal using the first tracking loop comprising the four-quadrant phase detector, the loop filter, and the voltage-controlled oscillator.

[0035] In addition, in combination with the third aspect, in a possible implementation of the third aspect, the tracking loop also includes: a two-quadrant phase detector and a second switch, and one end of the second switch is connected to the control circuit, and the other end is connected to the two-quadrant phase detector; the two-quadrant phase detector is connected to the loop filter and the voltage-controlled oscillator in sequence; in the absence of a navigation message to assist in tracking satellite signals, the control circuit controls the second switch to close and the first switch to open, and tracks the satellite signal using the second tracking loop including the two-quadrant phase detector, the loop filter, and the voltage-controlled oscillator.

[0036] In a fourth aspect, the present application further provides a terminal device comprising: a positioning chip and a SoC chip, wherein the positioning chip and the SoC chip can be connected via an interface. Specifically, the SoC chip is configured to receive differential corrections sent by a base station and transmit the differential corrections to the positioning chip. The positioning chip includes a processing circuit configured to perform positioning calculations using satellite signals and the differential corrections based on carrier phase differential technology. The satellite signals can be obtained via a transceiver. The satellite signals are satellite signals transmitted by at least one satellite.

[0037] In which, the processing circuit can be the processing circuit described in the aforementioned third aspect and any one of the implementation methods of the third aspect, and when the processing circuit executes the computer program stored in the memory, it can implement the positioning method in the aforementioned first aspect and any one of the implementation methods of the first aspect.

[0038] In a fifth aspect, the present application also provides a computer-readable storage medium having instructions stored therein, so that when the instructions are run on a computer or a processor, the method can be used to execute the aforementioned first aspect and various implementations of the first aspect.

[0039] In addition, the present application also provides a computer program product, which includes computer instructions. When the instructions are executed by a computer or a processor, the method of the aforementioned first aspect and various implementations of the first aspect can be implemented.

[0040] It should be noted that the beneficial effects corresponding to the technical solutions of the various implementation methods of the above-mentioned second to fifth aspects are the same as the beneficial effects of the above-mentioned first aspect and the various implementation methods of the first aspect. Please refer to the description of the beneficial effects in the above-mentioned first aspect and the various implementation methods of the first aspect for details, and no further details will be given. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 A schematic diagram of a structure using a mobile phone chip for positioning provided in this application;

[0042] Figure 2a A schematic diagram of the structure of a GPS system provided in this application;

[0043] Figure 2b A schematic diagram of a carrier phase and ranging code phase provided by this application;

[0044] Figure 2c A schematic diagram of the working principle of differential GPS provided in this application;

[0045] Figure 2d A schematic diagram illustrating the working principle of a GPS receiver provided in this application;

[0046] Figure 2e A schematic diagram of the structure of a phase-locked loop provided in this application;

[0047] Figure 2f A structural diagram of a phase-locked loop including an I / Q demodulation mechanism provided by this application;

[0048] Figure 2g A phasor representation diagram of I and Q signals provided by this application;

[0049] Figure 3 A waveform diagram of a carrier signal modulation provided by this application;

[0050] Figure 4 A schematic diagram of the structure of a positioning system provided in this application;

[0051] Figure 5 A flowchart of a positioning method provided in this application;

[0052] Figure 6 A flowchart of tracking and processing traditional satellite signals provided by this application;

[0053] Figure 7 A schematic diagram of the structure of a tracking loop provided in this application;

[0054] Figure 8 A waveform diagram of a carrier signal undergoing a hopping change provided in this application;

[0055] Figure 9 A flowchart of tracking and processing modern satellite signals provided for this application;

[0056] Figure 10 A schematic diagram of the structure of a positioning chip provided in this application;

[0057] Figure 11 A schematic diagram of the structure of a terminal device provided in this application. DETAILED DESCRIPTION

[0058] Before introducing the technical solution of this application, the relevant concepts and positioning principles are first explained and illustrated. Figures 2a to 2g The relevant concepts and principles that may be involved in the technical solution of this application are explained in detail.

[0059] 1. Positioning system

[0060] The technical solution of this application relates to a positioning system, which includes but is not limited to the GPS system, GLONASS system, Galileo satellite positioning system and China's Beidou satellite navigation system. This embodiment takes the GPS system as an example. Figure 2aAs shown, a GPS system consists of three components: the constellation, the ground-based monitoring system, and the user equipment system. In summary, the GPS system operates as follows: First, the GPS satellites in the constellation transmit satellite signals to the ground. Second, the ground-based monitoring system receives and measures the signals from each satellite to determine the satellite's orbit. It then transmits this orbital information to the satellites, which then relay this information in their transmitted signals. Finally, the user equipment system receives and measures the signals from each satellite, extracting the satellite's orbital information from the signals and determining the spatial position of the user receiver itself.

[0061] Generally, the space constellation and user equipment components have a one-way connection: GPS satellites transmit satellite signals and information to the user equipment component in a single direction. The space constellation component includes multiple satellites, such as operational and backup satellites. The ground monitoring component, which includes a master control station, injection stations, and monitoring stations, is responsible for data collection, satellite orbit monitoring, satellite clock error calculation, and GPS time base maintenance. The user equipment component can be understood as a GPS receiver (or GPS user receiver, or simply "receiver"), which processes received satellite signals to obtain the required measurements and navigation information, ultimately completing the user's positioning and navigation tasks.

[0062] 2. Pseudorange

[0063] Pseudorange is the most basic distance measurement a GPS receiver makes for satellite signals. It can be defined as the difference between the signal reception time and the signal transmission time multiplied by the speed of light. The signal reception time is directly read from the GPS receiver's clock, while the transmission time obtained by the GPS receiver requires a phase measurement of the ranging code (C / A code) in the signal. Specifically, this is obtained through the GPS receiver's code tracking loop. The C / A code (coarse acquisition) can be translated as the coarse acquisition code.

[0064] Typically, a C / A code is approximately 300 meters long, but in reality, it is 293 meters long. This is because a C / A code is 1023 chips long and has a code rate of 1.023 × 106 chips / second. Therefore, a C / A code is usually approximated to be 300 meters long. Therefore, in pseudorange measurement, the code tracking loop is limited to determining the code phase to a granularity of only a few meters, resulting in coarse positioning accuracy in pseudorange measurements.

[0065] 3. Carrier phase measurement value

[0066] The carrier signal has different phase values ​​at different locations on its propagation path and at the same time. Figure 2bAs shown in the figure, point S represents the zero phase center point of the satellite signal transmitter, and point A on the carrier signal propagation path is half a wavelength (i.e. 0.5λ) away from point S, and at any moment, the carrier phase of point A will always lag behind the phase of point S by 180°. The farther a point on the propagation path is from point S, the more the carrier phase of that point lags behind. Figure 2b In the example, the carrier phase at point A lags 180° behind that at point S, so point A is half a wavelength away from point S. The distance between points B and S is no longer 0.5λ, but (N+0.5)λ, where N is an unknown integer representing an integer number of cycles and λ is a wavelength. Similarly, the distance between the satellite and the receiver can be calculated by calculating the phase difference between the carrier phase at receiver point R and that at point S.

[0067] The receiver relies on its internal crystal oscillator to generate a replica of the carrier signal. The carrier phase measurement value φ can be defined as the phase of the receiver's replica of the carrier signal. The phase of the satellite carrier signal received by the receiver The difference between

[0068]

[0069] Among them, each carrier phase and phase difference are in cycles (or wavelengths), one cycle corresponds to a phase change of 360° (i.e. 2π radians), and the distance corresponds to one carrier wavelength. That is, the carrier phase measurement value φ in cycles is multiplied by the wavelength λ to convert it into a carrier phase measurement value in distance units. Because the phase of the replicated carrier signal It is exactly equal to the phase of the actual satellite carrier signal at the satellite end, so the carrier phase measurement value φ is also the phase change of the satellite carrier signal from the satellite end to the receiver end.

[0070] 4. Weekly Ambiguity

[0071] If it is assumed that the measurement of carrier phase is not affected by clock error, atmospheric delay and other errors, then according to the relationship between the carrier phase measurement value and the distance between two points on the signal propagation path discussed above, it can be expressed by formula (2):

[0072] φ=λ -1 r+N (2)

[0073] Where r is the geometric distance between the satellite and the receiver, and N is an unknown integer. In the GPS field, this unknown integer N is usually called the cycle ambiguity.

[0074] If various errors such as receiver clock error, satellite clock error and atmospheric delay are taken into account, the carrier phase measurement equation of equation (2) is:

[0075] φ=λ -1(r+c(δt u -δt s )-I+T)-N+ε φ (3)

[0076] Where φ is the carrier phase measurement value, λ is the wavelength, I is the ionospheric delay, T is the tropospheric delay, N is the cycle ambiguity, c is the speed of light, and ε φ is the noise, δt u is the receiver clock error, δt s is the satellite clock error.

[0077] In the embodiment of the present application, the carrier phase difference measurement value is referred to as carrier phase for short.

[0078] 5. Carrier tracking loop and cycle loss

[0079] In order to obtain the carrier phase of the received satellite signal, the receiver does not actually copy a carrier whose frequency is always f. Instead, the receiver uses its internal carrier tracking loop to try to copy a carrier at all times and make the frequency or phase of the carrier consistent with the carrier of the received satellite signal. In this way, the carrier tracking loop can basically be divided into two forms: frequency lock loop (FLL) and phase lock loop (PLL). Among them, the embodiment of the present application mainly relates to PLL, which continuously adjusts the phase of the copied carrier to make it consistent with the carrier phase of the received satellite signal, and then outputs the integrated Doppler measurement value.

[0080] Regardless of whether the carrier phase measurement output by the receiver is generated by an FLL or PLL, it always contains an unknown cycle-integrated ambiguity, N. When the carrier tracking loop loses and then regains lock to the signal, the cycle-integrated ambiguity in the carrier phase measurement output typically jumps. In other words, the cycle-integrated ambiguity value before and after the signal is lost is different. Sometimes, even though the receiver has not yet declared the signal completely lost, the carrier phase measurement output may experience a jump error of a whole or half cycle. This cycle-integrated ambiguity jump in the carrier phase measurement is generally referred to as loss of cycle.

[0081] 6. Differential positioning

[0082] Differential GPS is a widely used method that can effectively reduce various GPS measurement errors and can be applied to differential GPS systems such as the wide area augmentation system (WAAS) and the local area augmentation system (LAAS).

[0083] The fundamental principle of differential GPS positioning is based on the spatial and temporal correlations of satellite clock errors, satellite ephemeris errors, ionospheric delays, and tropospheric delays. For different receivers in the same region, the GPS measurements of these errors are approximately equal. One of the receivers is typically used as a reference, and the location of this receiver is called a base station (or base station). Accordingly, this receiver is also referred to as a base station receiver.

[0084] The position of the base station receiver (hereinafter referred to as the "base station") is known in advance, and the true geometric distance from the satellite to the base station can be accurately calculated. If the base station's distance measurement to the satellite is compared with this true geometric distance, the difference between them is equal to the base station's measurement error for this satellite. Because other receivers in the same area at the same time have related or similar errors in their distance measurements to the same satellite, such as Figure 2c As shown, the base station transmits the measurement error of its receiver to the mobile station (i.e., user receiver) through radio waves. The mobile station can then use the measurement error received from the base station to correct the distance measurement value of the mobile station to the same satellite, thereby improving the measurement and positioning accuracy of the mobile station. This is the basic working principle of differential GPS.

[0085] Optionally, the correction amount broadcast by the base station and used to reduce or even eliminate the GPS measurement error of the mobile station is called a differential correction amount.

[0086] 7. RTK positioning

[0087] Real-time kinematic (RTK) positioning is a technology that uses carrier phase observations for real-time dynamic relative positioning. The principle is that satellite data observed by a GPS receiver at a base station is transmitted in real time via a data communication link (radio station). A nearby GPS user receiver (also known as a rover) observes the satellites while also receiving electrical signals from the base station. By processing the received signals in real time, the rover's three-dimensional coordinates are determined and their accuracy is estimated.

[0088] RTK surveying requires at least two GPS receivers: one fixed at the base station and the other acting as a rover for point measurements. A data communication link is required between the two receivers to transmit observation data from the base station to the rover in real time. The rover uses RTK software to process the received data (satellite signals and differential corrections from the base station) in real time. This software primarily handles double-difference ambiguity resolution, baseline vector calculation, and coordinate conversion. Typically, the baseline length between the base and rover in an RTK system should not exceed 10 km, and the base station's position must be known.

[0089] Differential GPS positioning can be categorized as static and dynamic. For dynamic positioning applications, since the rover in a differential system moves relative to the base station, it must quickly resolve round-trip ambiguities and complete positioning in real time, achieving centimeter-level accuracy. RTK positioning technology allows for precise, real-time positioning of the rover, achieving higher accuracy than decimeters.

[0090] In addition, during the RTK positioning process, the LAMBDA (Least square AM Biguity decorrelation adjustment) algorithm can be used to obtain the double-differenced week ambiguity.

[0091] 8. Working principle of GPS receiver

[0092] GPS receiver, also known as GPS user receiver, referred to as "receiver", is a mobile station or a terminal device in the differential GPS positioning system. Its internal working process is as follows: Figure 2d As shown in the figure, it generally includes three functional modules: radio frequency (RF) front-end processing, baseband digital signal processing (DSP), and positioning and navigation operations. The RF front-end processing module receives all visible GPS satellite signals through the antenna. After filtering and amplification by the prefilter and preamplifier, it is mixed with the sine wave local oscillator signal generated by the local oscillator to down-convert it into an intermediate frequency (IF) signal. Finally, the analog-to-digital (A / D) converter converts the IF signal into a discrete-time digital IF signal.

[0093] Optionally, the RF front-end processing module is generally integrated into an application specific integrated circuit (ASIC) chip, and the integrated circuit can be called a radio frequency integrated circuit (RF Integrated circuit, RFIC).

[0094] The baseband digital signal processing module processes the digital intermediate frequency signal output by the RF front end and copies the local carrier signal consistent with the received satellite signal, thereby capturing and tracking the GPS signal, obtaining measurement values ​​such as carrier phase, and demodulating the navigation message.

[0095] Furthermore, in order to demodulate the navigation message from the received satellite signal, at the transmitting end of the GPS satellite signal, the GPS carrier signal is modulated with the C / A code and the navigation message data code. Correspondingly, at the receiving end of the GPS signal, in order to demodulate the navigation message data code from the received satellite signal, the baseband digital signal processing module needs to completely remove the carrier including the Doppler frequency shift in the digital intermediate frequency signal through mixing, and then completely remove the C / A code from the signal through C / A code correlation operation. The remaining signal is the navigation message data code modulated by biphase shift keying (BPSK).

[0096] On the one hand, the GPS receiver continuously adjusts the copied carrier inside it through the carrier tracking loop (referred to as carrier loop) so that the copied carrier frequency (or phase) is consistent with the carrier frequency (or phase) in the digital intermediate frequency signal, and then realizes carrier stripping through down-conversion mixing; on the other hand, the receiver continuously adjusts the copied C / A code inside it through the code tracking loop (referred to as code loop) so that the phase of the copied C / A code is consistent with the phase of the C / A code in the digital intermediate frequency signal, and then realizes C / A code stripping through code correlation operation.

[0097] 9. Phase-locked loop (PLL)

[0098] To completely strip the carrier from the digital IF input signal and downconvert it from the IF to baseband, the carrier loop includes a mixer, and the carrier it replicates must be consistent with the input carrier. If the carrier loop detects the phase difference between its replica and the input carrier and then adjusts the replica's phase accordingly to maintain phase alignment, this carrier loop implementation is called a phase-locked loop.

[0099] A phase-locked loop (PLL), also known as a phase-locked loop (PLL), is a carrier-locked loop designed to lock onto the phase of an input carrier signal. It is an electronic control loop that generates and outputs a periodic signal, continuously adjusting the phase of its output signal to ensure that the output signal remains in phase with the input signal. When the input and output signals are not yet aligned but are approaching phase alignment, the PLL operates in a pull-in state, exhibiting transient characteristics. If the transient process fails to converge or excessive interference causes the PLL to fail to lock, the PLL is said to be temporarily out of lock.

[0100] like Figure 2e As shown in Figure 1, a typical phase-locked loop mainly consists of three parts: a phase discriminator (or phase detector), a loop filter, and a voltage-controlled oscillator (VCO). i (t) and the output signal u generated by the voltage controlled oscillator o (t) are expressed as:

[0101] u i (t) = U i sin(ω i t+θ i ) (4)

[0102] u o (t) = U o sin(ω o t+θ o ) (5)

[0103] Among them, the angular frequency of the input signal ω i and initial phase θ i , and the angular frequency ω of the output signal o and initial phase θ o is a function of time. Used to identify the input signal u i (t) and the output signal u o The phase detector that detects the phase difference between the two phases (t) can be simply considered as a multiplier. i (t) and u o (t) After the phase detector multiplication operation, the phase detection result output signal u d (t) is equal to

[0104]

[0105] Among them, the gain K of the phase detector is d for

[0106] When the phase-locked loop enters the locked state, the angular frequency of its output signal ωo Very close to the angular frequency ω of the input signal i , that is, ω i ≈ω o , so the first term on the right side of the last equal sign in equation (6) is the angular frequency which is about 2 times of ω i The high-frequency signal component, and the second term is the phase detection result u d (t) is the low-frequency (or DC) signal component.

[0107] The loop filter is a low-pass filter used to reduce the noise in the loop. d (t) After passing through an ideal low-pass filter, its high-frequency signal components and noise are filtered out, so the output signal u of the filter is f (t) is equal to u d The low-frequency signal component in (t).

[0108] u f (t) = K d K f sinθ e (t) (7)

[0109] Among them, the coefficient K f is the filter gain, the phase difference sinθ e (t) is the phase difference between the input signal and the output signal of the phase-locked loop. e (t) = θ i -θ o When the signal is locked by the phase-locked loop, not only the angular frequency of the output signal ω o Equal to ω i , and the initial phase value of the output signal θ o It is also very close to θ i , that is, the phase difference sinθ e The value of (t) is close to zero.

[0110] 10. In-phase / quadrature (I / Q) demodulation

[0111] In addition, due to the BPSK modulation characteristics of GPS signals, GPS receiver phase-locked loops usually use in-phase / quadrature (I / Q) demodulation to help complete carrier stripping, phase detection, and data demodulation of the input signal.

[0112] like Figure 2f The phase-locked loop shown here includes an I / Q demodulation mechanism, where the continuous-time signal u is the input to the system. i (t) can be expressed as,

[0113]

[0114] Where D(t) represents the data code modulated on the carrier. The difference between Equation (8) and Equation (4) is that the signal amplitude of the former is a constant, while the amplitude of the latter is Multiply by the data level D(t) containing information, which is ±1, where the sign of D(t) changes with the jump of the data code, and n represents the mean value of 0 and the variance of is Gaussian white noise.

[0115] Figure 2f The phase-locked loop shown in the figure replicates two sine and cosine carrier signals with a phase difference of 90°, and multiplies each of them with the input signal to achieve down-conversion (or carrier stripping) of the input signal. The loop branch that mixes the input signal with the sine carrier replica signal is called the in-phase branch (abbreviated as "I branch"), and the other loop branch that mixes with the cosine carrier replica signal is called the quadrature branch (abbreviated as "Q branch"). One function of the I / Q demodulation method is to convert the input signal u i The data code D(t) in (t) is demodulated.

[0116] Phase angle r of the phasor p (t) is equal to the phase difference φ between the input signal and the replica signal c (t), i.e.

[0117]

[0118] The angle value returned by the two-quadrant inverse tangent function arctan is between -π / 2 and +π / 2. Figure 2g The vector diagram shown, I p (t) and Q p (t) distribution as the coordinate value on the X-axis and Y-axis, then from the coordinate origin 0 to the data point (I p (t), Q p The directed line of (t)) is exactly the phasor r p (t), and the X axis turns to the phase r p The angle (t) is equal to the phase difference φ c (t).

[0119] The following is an explanation of the technical problems to be solved by the technical solution of this application.

[0120] The technical solution of the embodiments of this application is mainly used to solve two technical problems. On the one hand, it uses RTK carrier phase difference technology to improve the positioning accuracy of mobile phones to meet users' high-precision needs. On the other hand, it uses satellite signal tracking information on the chip to detect cycle slips and half-cycle slips, implement half-cycle slip repair, and improve the stability and related performance of carrier phase use, so that RTK carrier phase difference technology can be stably applied on mobile phones.

[0121] Specifically, the reasons why the carrier phase cycle jump and half cycle jump occur in the second aspect are explained below.

[0122] Take the occurrence of half cycle jump as an example, Figure 3 As shown in the figure, it is assumed that the satellite signal transmitted by the satellite contains an input carrier. After receiving it, the receiver demodulates it to obtain a navigation message, which contains a random number sequence composed of +1 and -1. Among them, the first half is the carrier waveform transmitted by the +1 sequence, and the second half is the carrier waveform transmitted by the real -1 sequence. Figure 3 The waveform of the bold line part in the middle and rear half is a hypothetical carrier waveform modulated as a +1 sequence transmission. It can be seen that the phase difference between the first and second half sequences is 180°, indicating that the carrier phase is flipped during modulation. The modulation process includes the basic communication principle BPSK modulation. The specific BPSK modulation process is not described in detail in this embodiment.

[0123] When the local receiver experiences a half-cycle jump in the carrier phase during BPSK modulation, the +1 sequence carrier waveform can be represented as local carrier 1 (Local Carrier 1), which is the carrier waveform copied by the receiver chip. Under normal circumstances, the receiver tracks the carrier and locks onto the correct carrier (without 180° phase ambiguity). For the -1 sequence carrier waveform, the copied waveform of local carrier 2 (Local Carrier 2) during carrier tracking is Figure 3 In the third row of the carrier waveform shown, there is a 180° phase ambiguity due to the -1 sequence navigation message being modulated internally by the receiver, which in turn causes a half-cycle jump (180° phase jump) in the carrier phase.

[0124] In this case, if the local receiver uses a two-quadrant phase detector to identify the phase, due to its limited phase detection range, it cannot distinguish the bit transitions of the +1 and -1 sequences. Therefore, it will track the waveform of the input carrier. For example, when tracking the second half of the input carrier, excluding the influence of the navigation message, it will be modulated according to the carrier waveform of the hypothetical +1 sequence (thick line), but the receiver actually tracks the carrier waveform of the -1 sequence (thin line). The two differ by 180° in phase ambiguity, which affects positioning accuracy.

[0125] In addition, since the amplitude of the carrier phase half-cycle jump is small, it is not easy to detect.

[0126] The following combination Figures 4 to 11 The technical solutions of the embodiments of the present application are introduced in detail.

[0127] This embodiment provides a positioning method that uses carrier phase differential technology, or RTK technology, to perform RTK positioning calculations through satellite carrier phase measurements and differential corrections, thereby improving the positioning accuracy of a terminal device.

[0128] In a GPS system, such as Figure 4 As shown, the GPS system includes multiple GPS satellites, reference stations, and rover stations. Currently, there are at least three GPS satellites used for positioning, such as Satellite 1, Satellite 2, and Satellite 3. The reference station is a reference station receiver in the aforementioned differential positioning system, and its position is fixed and known.

[0129] The mobile station is a device to be positioned. It is also a terminal device that is located near the base station and has a non-fixed position.

[0130] The terminal device may refer to user equipment (UE), access terminal, subscriber unit, subscriber station, mobile station, mobile station, mobile device, wireless communication device, user agent, or user device, etc. Optionally, the terminal device may also be a cellular phone, a cordless phone, a Session Initiation Protocol (SIP) phone, a personal digital assistant (PDA), a handheld device with wireless communication capabilities, such as a mobile phone, a computing device, a vehicle-mounted device, a wearable device, a terminal device in a future 5G network, or a terminal device in a future evolved public land mobile network (PLMN), etc. This embodiment does not limit the form and structure of the terminal device.

[0131] Furthermore, the terminal device includes: a positioning chip and a system on chip (SoC) chip, and the positioning chip and the SoC chip are connected via at least one interface.

[0132] Optionally, the positioning chip is a global navigation satellite system (GNSS) positioning chip. The GNSS positioning chip has position positioning and solution functions, wherein the GNSS may include GPS, global navigation satellite system (GLONASS), Beidou navigation satellite system (BDS), etc.

[0133] See also Figure 5 , is a flow chart of a positioning method provided in this embodiment. The method can be used to position any of the aforementioned terminal devices, and the terminal device includes a positioning chip and a SoC chip. Specifically, the method includes:

[0134] 101: The positioning chip receives a satellite signal transmitted by at least one satellite.

[0135] Generally speaking, satellite signals transmitted by satellites can be divided into three layers: carrier, pseudo-code, and data code. Within these three layers, the pseudo-code and data code are modulated onto a sinusoidal carrier wave, which is then broadcast by the satellite. Furthermore, each GPS satellite can transmit carrier radio signals using two L-band frequencies (L1 and L2).

[0136] The satellite signals may include, by frequency, a first satellite signal and a second satellite signal. Specifically, the first satellite signal is a traditional satellite signal, and the second satellite signal is a modernized satellite signal. Traditional satellite signals generally include GPSL1C / A, BeidouB1I, QZSSL1CA, and other satellite signals. GPSL1C / A represents a satellite signal with a nominal carrier frequency of 1575.42 MHz in the GPS system. Modernized satellite signals generally include GPSL5, GALE5, and QZSSL5 satellite signals. GPSL5C represents a satellite signal with a nominal carrier frequency of 1176.45 MHz in the GPS BLOCK III system. It should be understood that the satellite signals may also include signals of other frequencies.

[0137] In addition, the method includes:

[0138] 1011: The positioning chip demodulates the satellite signal to obtain first location information of the terminal device, where the first location information is rough location information of the terminal device.

[0139] 1012: The positioning chip sends the rough position information to the reference station.

[0140] 1013: The reference station receives the coarse position information and sends a differential correction value to the terminal device.

[0141] Specifically, the positioning chip performs PVT solution based on the information carried by the satellite signal, as well as the measured pseudorange observations, Doppler observations and ephemeris information, and then obtains the rough position information through the least squares algorithm (LSQ). Furthermore, a specific demodulation process includes the positioning chip performing carrier demodulation and pseudocode despreading on the received satellite signal to obtain a data code, and then compiling the data code into a navigation message according to the format of the navigation message. The navigation message contains important information for positioning, such as time, satellite orbit, and ionospheric delay. The positioning chip then completes coarse position positioning based on the navigation message to obtain coarse position information.

[0142] In addition, after step 101, the following steps are also included:

[0143] 101 ′: The positioning chip performs synchronous detection on the satellite signal, and tracks the satellite signal using a tracking loop after completing the synchronous detection to obtain carrier phase tracking information of the satellite signal, wherein the carrier phase tracking information includes a carrier phase measurement value.

[0144] 102: The positioning chip obtains the differential correction value sent by the base station through the SoC chip.

[0145] The SoC chip is coupled to the positioning chip, and the SoC chip is connected to a communication module. The communication module can receive differential corrections from the reference station. The SoC chip obtains the differential corrections received by the communication module and transmits them to the positioning chip. The communication module can be a short-range communication module, and the SoC chip can communicate with other communication devices via the short-range communication module to obtain the differential corrections forwarded by other communication devices; or the communication module can be a transceiver, and the SoC chip includes a baseband processor coupled to the transceiver. The baseband processor accesses a mobile communication network via the transceiver and further obtains the differential corrections from the network. It should be understood that a reference station is generally an unmanned satellite monitoring device that can access a communication network and transmit the monitored data via the communication network.

[0146] The differential correction includes carrier phase measurements of common-view satellite signals, which are satellite signals tracked jointly by the terminal device and the reference station and originate from the same GPS satellite. Furthermore, the differential correction also includes parameters such as pseudorange observations, signal-to-noise ratio, ionospheric delay, and tropospheric delay of the common-view satellites.

[0147] In addition, before obtaining the differential correction value sent by the reference station, the method further includes: determining the reference station to ensure that the reference station is located near the terminal device, thereby providing the terminal device with accurate differential correction value. Specifically, the reference station can be determined based on the rough position information sent by the terminal device.

[0148] One possible implementation method is that the terminal device sends the rough location information to a master control station, and the master control station selects a reference station that is closer to the terminal device based on the rough location information. The reference station can be a virtual reference station, and then the virtual reference station sends the differential correction value measured by it to the terminal device.

[0149] 103: The positioning chip performs positioning calculation based on the carrier phase difference technology using the satellite signal and the differential correction value.

[0150] Among them, utilizing the satellite signal refers to the carrier phase tracking information of the satellite signal obtained in the above-mentioned "step 101'", and the differential correction amount refers to the carrier phase measurement value of the common view satellite signal sent by the reference station in the above-mentioned "step 102". Then step 103 specifically includes: the positioning chip uses the carrier phase tracking information of the satellite signal and the differential correction amount to perform positioning calculation to obtain the position information of the terminal device.

[0151] Specifically, the positioning chip identifies common-view satellites. These are GPS satellites tracked by both the reference station and the terminal device. Specifically, the satellite signals tracked by the terminal device and the differential correction values ​​sent by the reference station have the same satellite numbers. The positioning chip then uses double-difference calculations to determine the relationship between the carrier phase measurement and the round-trip ambiguity. Finally, the round-trip ambiguity N is calculated based on this relationship.

[0152] When using the carrier phase differential technology, i.e., RTK technology, to eliminate the carrier phase measurement error in the coarse position information, the differential methods include single difference, double difference, and triple difference. This embodiment takes double difference as an example. Each double difference measurement value involves the measurement value of two devices on two satellites at the same time. For example, assuming that the two devices in the positioning system are the terminal device j and the reference station i, and the two co-viewing satellites are satellite p and satellite q, then the relationship between the carrier phase measurement value obtained by the terminal device j through double difference solution is as follows:

[0153]

[0154]

[0155]

[0156] Among them, base station i, terminal device j, satellite p and satellite q, λ is the carrier wavelength, is the geometric distance between the reference station i and the satellite p, is the geometric distance between terminal device j and satellite p, is the geometric distance between the reference station i and the satellite q, is the geometric distance between terminal device j and satellite q; I is the ionospheric delay, T is the tropospheric delay, is the weekly ambiguity of reference station i relative to satellite p, is the weekly ambiguity of terminal j relative to satellite p, is the weekly ambiguity of reference station i relative to satellite q, is the weekly ambiguity of terminal device j relative to satellite q; ε is noise, c is the speed of light, δt i is the terminal equipment clock error, δt p is the satellite p clock error, δt q is the satellite q clock error, is the carrier phase measurement value of reference station i relative to satellite p; is the carrier phase measurement value of terminal device j relative to satellite p, is the carrier phase measurement value of reference station i relative to satellite q; is the carrier phase measurement value of terminal device j relative to satellite q.

[0157] Optionally, the differential correction amount in step 102 includes: the carrier phase measurement value of the reference station i relative to the satellite p and the carrier phase measurement of reference station i relative to satellite q As well as ionospheric delay I and tropospheric delay T, etc.

[0158] According to the above formulas (10) to (13), we can obtain:

[0159]

[0160]

[0161]

[0162] According to formulas (14) and (15),

[0163] According to formulas (16) and (17),

[0164] According to formula (19), a fixed carrier cycle ambiguity can be solved Then the corrected carrier phase measurement value is obtained And using the corrected carrier phase measurement value Perform positioning calculation to obtain second location information of the terminal device. The second location information is the precise location information of the terminal device.

[0165] This method proposes a new RTK architecture based on a mobile phone GNSS positioning chip. Through carrier phase differential technology, the terminal device can correct the rough positioning results, achieving sub-meter positioning accuracy, further improving the performance of mobile phone positioning and navigation to meet user needs.

[0166] In addition, this method realizes lane-level navigation positioning; it achieves precise positioning for navigation positioning in open scenes such as going up and down elevated roads, lane changes, and lane changes at highway intersections, meeting the application needs of in-vehicle navigation, thereby effectively reducing the cost of vehicle navigation applications (such as in-vehicle navigation systems and ETC toll collection systems), increasing related applications in the field of mobile phone positioning and navigation, and improving market competitiveness.

[0167] In addition, the technical solution of this embodiment can also detect cycle jumps and half cycle jumps that occur during carrier phase tracking, and compensate for the phase that produces the half cycle jump, thereby improving positioning accuracy.

[0168] The specific process is step 101' of the aforementioned embodiment: the positioning chip performs synchronous detection on the satellite signal, and after completing the synchronous detection, tracks the satellite signal using a tracking loop to obtain carrier phase tracking information of the satellite signal, wherein the carrier phase tracking information includes a carrier phase measurement value.

[0169] The following is a detailed description of “step 101 ′” in the aforementioned embodiment.

[0170] For example, when the satellite signal is a traditional satellite signal, such as GPSL1C / A, BeiDou B1I, QZSSL1CA, or a satellite signal with a carrier frequency of 1575.42 MHz, Figure 6 As shown, step 101' specifically includes:

[0171] 201: The positioning chip performs synchronization detection on the traditional satellite signal to detect whether it has completed bit synchronization.

[0172] Bit synchronization, also known as bit synchronization, involves the receiving channel determining the position of the current satellite signal within a data bit based on a specific algorithm. Alternatively, it involves determining the starting edge of a bit in the received satellite signal. Furthermore, positioning chips utilize multiple channels to receive traditional satellite signals transmitted by multiple GPS satellites. Capturing and tracking each satellite signal requires first achieving bit synchronization with the satellite signal, i.e., finding the edge of the data bit in the received satellite signal. Frame synchronization then requires finding the starting edge of a subframe in the satellite signal.

[0173] Optionally, the positioning chip may use a histogram to detect whether bit synchronization is completed.

[0174] 202: If not, that is, the bit synchronization is not completed, then exit the tracking process and recapture the satellite signal.

[0175] 203: If yes, that is, the bit synchronization is completed, positioning and tracking the traditional satellite signal is performed.

[0176] At the same time, the positioning chip also performs positioning and solution on the traditional satellite signal to obtain the rough location information of the terminal device. Specifically, the process of the positioning chip obtaining and sending the rough location information is the same as steps 1011 to 1013 of the aforementioned embodiment, and will not be repeated here.

[0177] In step 203, the positioning chip performs positioning and tracking on the traditional satellite signal, specifically including:

[0178] 2031: Determine whether there is a navigation message to assist in tracking the traditional satellite signal.

[0179] 2032: If yes, that is, there is navigation message-assisted tracking, a four-quadrant phase detector is used to track the traditional satellite signal to obtain a first carrier phase measurement value.

[0180] 2033: If no, that is, there is no navigation message-assisted tracking, a two-quadrant phase detector is used to track the traditional satellite signal to obtain a second carrier phase measurement value.

[0181] When the tracking loop locates and tracks traditional satellite signals, the phase-locked loop outputs Doppler shift, integrated Doppler, and carrier phase measurements based on the state of the copied carrier signal. At the same time, the code tracking loop outputs code phase and pseudorange measurements based on the state of the copied C / A code signal. The carrier loop discriminator can also additionally modulate the navigation message data bits on the satellite signal.

[0182] The positioning chip includes a tracking loop, and the tracking loop includes a phase-locked loop. The structure of the phase-locked loop can be similar to the aforementioned Figure 2eThe structure shown in FIG. 1 includes a phase detector, a loop filter, and a voltage-controlled oscillator. Alternatively, Figure 7 As shown, it includes an in-phase branch, an orthogonal branch, a control circuit, a first switch K1, a second switch K2, a four-quadrant phase detector, a two-quadrant phase detector and other components.

[0183] Optionally, the two-quadrant phase detector is a Costas phase-locked loop (PLL). Specifically, a Costas PLL refers to a PLL that uses an appropriate phase detector to operate in a data code modulated carrier signal and is insensitive to the 180° carrier phase change caused by data bit jumps. The difference between a Costas PLL and a four-quadrant phase detector lies in their different phase detection ranges. The Costas PLL primarily uses a two-quadrant inverse tangent function method for phase discrimination and is a two-quadrant phase detector with a phase detection range of -90° to +90°. In contrast, a four-quadrant phase detector has a phase detection range of -180° to +180°.

[0184] Generally, the phase range from -90° to +90° or -180° to +180° is called the pull-in range of the phase detector.

[0185] When the phase-locked loop is locked, the phase difference between the replica carrier and the received carrier is close to zero. The BPSK modulation mechanism in the satellite signal causes the carrier phase of the received signal to jump at the data bit level, for example, from +1 to -1, or from -1 to +1, resulting in a 180° phase jump. For a two-quadrant phase detector, when the actual phase difference is greater than 90°, it will output a phase detection result less than 0°. In this case, the loop's replica carrier phase will be incorrectly adjusted in the opposite direction, ultimately causing the tracking loop to lose signal lock. Therefore, to avoid the pull-in range limitations of the two-quadrant phase detector, a four-quadrant phase detector with a larger pull-in range is used for phase detection.

[0186] See also Figure 7 , a circuit diagram of a tracking loop, including an in-phase branch, a quadrature branch, a four-quadrant phase detector, a two-quadrant phase detector, a first switch K1, a second switch K2, a control circuit, a loop filter, and a voltage-controlled oscillator. K1 is connected to the four-quadrant phase detector, and K2 is connected to the two-quadrant phase detector. The control circuit is used to control the closing and opening of K1 and K2. Specifically, when the control circuit closes K1 and opens K2, the four-quadrant phase detector, loop filter, and voltage-controlled oscillator form a first tracking loop. When K1 is opened and K2 is closed, the two-quadrant phase detector, the loop filter, and the voltage-controlled oscillator form a second tracking loop.

[0187] In step 2031, if navigation message-assisted tracking is available, step 2032 is executed, where the positioning chip tracks the conventional satellite signal using the first tracking loop and outputs the first carrier phase measurement value. If navigation message-assisted tracking is not available, step 2033 is executed, where the positioning chip tracks the conventional satellite signal using the second tracking loop and outputs the second carrier phase measurement value.

[0188] 2034: The positioning chip records the carrier phase tracking information.

[0189] The carrier phase tracking information includes the first carrier phase measurement value or the second carrier phase measurement value, as well as parameters such as the Doppler shift and integrated Doppler of the carrier signal locally replicated by the positioning chip. In addition, the carrier phase tracking information also includes other information, such as whether the carrier phase tracking is continuous and whether there is a loss of lock, to facilitate subsequent carrier phase cycle slip determination.

[0190] It should be noted that, when tracking traditional signals, the positioning chip records the changes in the carrier phase in real time, so as to subsequently detect whether a phase cycle slip occurs.

[0191] In the process of tracking traditional satellite signals, this embodiment expands the pull-in range by using a four-quadrant phase detector, thereby avoiding the 180° phase ambiguity generated when digital bits jump.

[0192] Specifically, if Figure 8 As shown, it is assumed that the pseudo-random sequence is a string of data code sequences, such as

[0193] 1,1,1,1,1,-1,1,1,-1,-1,-1,1,-1,-1,1,-1,-1,-1,-1,1,

[0194] Figure 8 The first line in the figure represents the input carrier signal, and the second line represents the modulated pseudo-random sequence. When the satellite signal is broadcast, the modulated pseudo-random sequence needs to be multiplied by the carrier signal to obtain a pseudo-random sequence that is identical to the input carrier signal and has been eliminated. At this time, the original data code sequence is converted into a full 1 sequence.

[0195] 1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,

[0196] If a two-quadrant phase detector is used for phase identification, a 180° phase ambiguity will be generated. If a four-quadrant phase detector is used for phase identification, due to its large pull-in range, it can obtain the same carrier signal as the input carrier, avoiding the 180° phase ambiguity generated when the two-quadrant phase detector is used for phase identification.

[0197] After the positioning chip tracks the traditional satellite signal in step 203, the method further includes:

[0198] 204: The positioning chip determines whether a cycle slip occurs in the phase of the tracked carrier.

[0199] Specifically, in one possible implementation, if a cycle slip occurs in the first carrier phase measurement value output after the first tracking loop, tracking fails, the process ends, and satellite signal reacquisition is required. If a cycle slip does not occur, that is, the determination result is "No," step 207 is executed.

[0200] In another possible implementation, if a cycle slip occurs in the second carrier phase measurement value output after the second tracking loop, tracking fails, the process ends, and satellite signal reacquisition is required. If a cycle slip does not occur, that is, the determination result is "No," step 205 is executed.

[0201] 205: Query the frame header of the demodulated satellite signal to determine whether it is in phase with the actual navigation message frame header, that is, to detect whether the carrier phase has a half-cycle jump.

[0202] If yes, that is, in phase with the actual navigation message frame header, it indicates that no half cycle jump has occurred, and step 207 is executed. If no, that is, in phase opposite to the actual navigation message frame header, it indicates that a half cycle jump has occurred, and step 206 is executed.

[0203] 206: Perform phase compensation on the second carrier phase measurement value to obtain a third carrier phase measurement value. For example, add 0.5 cycles to the second carrier phase measurement value to correct the 180° phase ambiguity caused by the half cycle jump.

[0204] 207: Perform positioning calculation using the carrier phase tracking information and the differential correction value to obtain second position information of the terminal device. This step is the same as "step 103" in the above embodiment, specifically including:

[0205] The differential correction amount is the measurement amount sent by the reference station in the aforementioned step 1013, including information such as carrier phase measurement value, ionospheric delay and tropospheric delay. The carrier phase tracking information includes the first carrier phase measurement value, the second carrier phase measurement value, or the third carrier phase measurement value. Specifically,

[0206] 207-1: Continuing from step 204, the positioning chip obtains a corrected carrier phase measurement value based on the differential correction value and the first carrier phase measurement value, and uses the corrected carrier phase measurement value to perform positioning calculation to obtain the second position information. Or,

[0207] 207-2: Continuing from step 205, the positioning chip obtains a corrected carrier phase measurement value based on the differential correction value and the second carrier phase measurement value, and uses the corrected carrier phase measurement value to perform positioning calculation to obtain the second position information. Or,

[0208] 207-3: Continuing from step 206, the positioning chip obtains a corrected carrier phase measurement value according to the differential correction value and the third carrier phase measurement value, and performs positioning calculation using the corrected carrier phase measurement value to obtain the second position information.

[0209] Furthermore, the process of obtaining the second position information using the differential correction value and the carrier phase measurement value is described in step 103 above and will not be repeated here. It should be noted that this embodiment does not restrict the order of the aforementioned carrier phase tracking process, i.e., step 203, and the demodulation process for obtaining coarse position information, i.e., steps 1011 to 1013.

[0210] This embodiment provides a method for tracking and processing traditional satellite signals. When the positioning chip detects that the traditional satellite signal has navigation message-assisted tracking, it uses the carrier tracking loop of the four-quadrant phase detector to track the carrier signal, thereby avoiding the use of the tracking loop of the two-quadrant phase detector to adjust the phase of the replica carrier in the opposite direction, which ultimately causes the tracking loop to lose signal lock.

[0211] In addition, while performing carrier phase tracking, carrier phase tracking information is recorded and cycle slips are detected to resolve the cycle slip problem caused by the carrier phase measurement value. In addition, when a half cycle slip is detected in the subsequent carrier phase measurement value, 0.5 cycle phase is added to compensate, thus overcoming the 180° phase ambiguity caused by phase loss and resolving the half cycle slip problem caused by positioning chip replication.

[0212] Similarly, when the satellite signal received by the receiving chip in step 101 is a second satellite signal, i.e., a modern satellite signal, such as GPSL5, GALE1, GALE5, QZSSL5, or BD1C, most of these signals are in the 1176.42 MHz frequency band. In addition, the modern satellite signal includes a data channel and a pilot channel. The tracking and processing flow is as follows: Figure 9 As shown, specifically including:

[0213] 301: The positioning chip detects whether the modern satellite signal has completed bit synchronization. The specific process is the same as step 201 in the above embodiment and will not be repeated here.

[0214] 302: If not, that is, the bit synchronization is not completed, then exit the tracking process and recapture the satellite signal.

[0215] 303: If yes, then track and process the modernized satellite signal. Specifically, this includes:

[0216] 3031: The positioning chip uses a four-quadrant phase detector to track a modern satellite signal. After the modern satellite signal is processed by a first tracking loop including the four-quadrant phase detector, the carrier phase tracking information is output. The carrier phase tracking information includes a fourth carrier phase measurement value.

[0217] 3032: Record the carrier phase tracking information. The specific process is the same as steps 2032 and 2034 of the above embodiment.

[0218] 304: The positioning chip determines whether a cycle slip occurs in the phase of the tracked carrier.

[0219] If yes, then the carrier phase tracking fails and the process ends. If no, that is, no cycle slip occurs, then step 305 is executed.

[0220] 305: The positioning chip performs positioning calculation using the differential correction value and the fourth carrier phase measurement value to obtain second position information of the terminal device.

[0221] The differential correction value is the differential correction value sent by the reference station in steps 1011 to 1013 of the aforementioned embodiment. For details, please refer to the description of the aforementioned embodiment and will not be repeated here. Furthermore, the processing of step 305 is also the same as step 207 of the aforementioned embodiment and will not be repeated here.

[0222] In this embodiment, during the tracking and processing of modern satellite signals, since modern satellite signals have both data and pilot channels, there's no need to determine whether navigation messages are assisting tracking, as is done in traditional satellite signal tracking. Instead, the pilot channel can be directly processed. Once the positioning chip detects that the modern satellite signal has completed bit synchronization, it can directly track the signal using a four-quadrant phase detector to determine the satellite signal's carrier phase measurement value.

[0223] In addition, while tracking the carrier phase, the positioning chip also records carrier phase tracking information and filters out cycle slips, thus resolving the cycle slip problem that occurs when using carrier phase measurements for differential positioning. For modern satellite signals, tracking utilizes pilot channel processing, a four-quadrant phase detector, and a phase-locked loop to avoid half-cycle slips in the carrier phase.

[0224] The following describes an apparatus embodiment corresponding to the above method embodiment.

[0225] Figure 10 This is a schematic diagram of the structure of a positioning device provided in an embodiment of the present application. The device can be a terminal device, or a positioning chip located in the terminal device. Furthermore, the device can perform all the steps of a positioning method in the aforementioned embodiment.

[0226] Specifically, if Figure 10 As shown, the device may include: a transceiver circuit 41, a processing circuit 42 and a storage unit 43. In addition, the device may also include other units or modules. This application does not limit this.

[0227] Among them, the transceiver circuit 41 is used to receive satellite signals transmitted by at least one satellite; the processing circuit 42 is used to obtain the differential correction amount sent by the base station through the system-on-chip SoC chip, and based on the carrier phase difference technology, use the satellite signal and the differential correction amount to perform positioning calculation.

[0228] Optionally, in a specific implementation of this embodiment, the processing circuit 42 is further configured to, after the positioning chip receives a satellite signal transmitted by at least one satellite, perform synchronization detection on the satellite signal, and after completing the synchronization detection, track the satellite signal using a tracking loop to obtain carrier phase tracking information of the satellite signal. The processing circuit 42 specifically uses the carrier phase tracking information of the satellite signal and the differential correction value to perform positioning calculations to obtain the location information of the terminal device.

[0229] Furthermore, the satellite signal transmitted by the at least one satellite includes a first satellite signal. The processing circuit 42 is specifically configured to, after completing the synchronization detection, determine whether a navigation message assists tracking; if so, track the first satellite signal using a first tracking loop, wherein the first tracking loop includes a four-quadrant phase detector, and the first satellite signal outputs a first carrier phase measurement value after passing through the four-quadrant phase detector. The processing circuit 42 is further configured to, before performing the positioning calculation, determine whether a carrier phase cycle slip has occurred based on the first carrier phase measurement value; if not, perform the positioning calculation using the carrier phase tracking information of the satellite signal and the differential correction value.

[0230] Optionally, in another specific implementation of this embodiment, the processing circuit 42 is also used to track the first satellite signal using the second tracking loop after completing the synchronization detection, if there is no navigation message to assist in tracking, and the second tracking loop includes a two-quadrant phase detector, and the first satellite signal outputs a second carrier phase measurement value after passing through the two-quadrant phase detector.

[0231] Optionally, the two-quadrant phase detector is a Costas phase-locked loop.

[0232] The processing circuit 42 is also used to determine whether a carrier phase cycle slip occurs based on the second carrier phase measurement value before performing the positioning calculation; if not, query the frame header of the navigation message on the demodulated first satellite signal to determine whether it is in phase with the actual navigation message frame header; if it is in phase, use the carrier phase tracking information of the satellite signal and the differential correction amount to perform positioning calculation.

[0233] Optionally, in another specific implementation of this embodiment, the processing circuit 42 is further configured to determine that, when the second carrier phase measurement value is out of phase with the actual navigation message frame header, perform phase compensation on the second carrier phase measurement value to obtain a third carrier phase measurement value. The processing circuit 42 is specifically configured to perform positioning calculation using the third carrier phase measurement value and the differential correction amount.

[0234] Optionally, if the satellite signal transmitted by the at least one satellite includes a second satellite signal, the processing circuit 42 is specifically used to track the second satellite signal using a first tracking loop, the first tracking loop includes a four-quadrant phase detector, and the second satellite signal outputs a fourth carrier phase measurement value after passing through the four-quadrant phase detector.

[0235] In addition, the processing circuit 42 is also used to determine whether a carrier phase cycle slip occurs based on the fourth carrier phase measurement value before performing the positioning calculation. If not, the positioning calculation is performed using the carrier phase tracking information of the satellite signal and the differential correction amount.

[0236] Optionally, in another specific implementation of this embodiment, the processing circuit 42 is also used to demodulate the satellite signal after receiving the satellite signal transmitted by at least one satellite to obtain the coarse position information of the terminal device; the transceiver circuit 41 is also used to send the coarse position information to the base station so that the base station can feed back the differential correction amount based on the coarse position information.

[0237] Optionally, the differential correction includes a carrier phase measurement value of a common view satellite signal, where the common view satellite signal is a satellite signal jointly tracked by the positioning chip and the reference station. The processing circuit 42 is specifically configured to perform a differential calculation using the carrier phase measurement value of the common view satellite signal and the first carrier phase measurement value to obtain a first integral ambiguity, determine a corrected carrier phase measurement value using the first integral ambiguity, and perform a positioning calculation based on the corrected carrier phase measurement value to obtain location information of the terminal device.

[0238] In addition, at the specific hardware implementation level, this embodiment provides a terminal device, such as Figure 11 As shown, it includes: a communication module 110, a SoC chip 120 and a positioning chip 130, and the SoC chip 120 and the positioning chip 130 are connected through a communication interface, and the communication module 110 and the SoC chip 120 can be connected through a communication bus.

[0239] The communication module 110 is used to establish a communication channel, allowing the terminal device to connect to the network through the communication channel, thereby realizing communication transmission between the terminal device and other devices. The communication module 110 can be a module that performs transceiver functions. For example, it can include communication modules such as a wireless local area network (WLAN) module, a Bluetooth module, a baseband module, and a radio frequency (RF) circuit corresponding to the communication device, for performing wireless local area network communication, Bluetooth communication, infrared communication and / or cellular communication system communication, such as wideband code division multiple access (WCDMA) and / or high speed downlink packet access (HSDPA). In addition, the communication module 110 supports direct memory access.

[0240] Furthermore, the communication module 110 includes various transceiver modules, such as a transceiver and an antenna, such as antenna 1. In addition, the communication module 110 may also include components such as a preamplifier, a downconverter, an A / D converter, and a baseband processor. In different embodiments of the present application, the various transceiver modules in the communication module 110 generally appear in the form of integrated circuits and can be selectively combined without having to include all transceiver modules and corresponding antenna groups. For example, the communication module 110 may also include a radio frequency chip and a corresponding antenna to provide communication functions in a cellular communication system to enable access to the communication network.

[0241] In this embodiment, the communication module 110 is configured to receive the differential correction value sent by the reference station and transmit it to the SoC chip 120 .

[0242] The positioning chip 130 is used to implement functions such as tracking and processing satellite signals, and positioning calculation, etc. Specifically, the positioning chip 130 includes a transceiver 1301, a digital signal processor (DSP) 1302, a microprocessor 1303, a memory 1304, and an interface 1305.

[0243] Transceiver 1301 can be used to receive satellite signals transmitted by at least one GPS satellite, such as traditional satellite signals and modern satellite signals. Transceiver 1301 includes at least one antenna, such as antenna 2, and receives the satellite signal via antenna 2. After filtering and amplification by a prefilter and preamplifier, the signal is mixed with a sinusoidal local oscillator signal generated by a local oscillator to down-convert it into an intermediate frequency (IF) signal. Finally, an analog-to-digital (A / D) converter converts the IF signal into a discrete-time digital IF signal.

[0244] DSP 1302 may include components such as a digital signal processor and a tracking loop. The digital signal processor uses the digital intermediate frequency (IF) signal output by the radio frequency (RF) front end to replicate a local carrier and local pseudo-code signal consistent with the received satellite signal, thereby enabling the capture and tracking of GPS satellite signals. At the GPS satellite signal transmitter, the GPS carrier signal is modulated with a C / A code and navigation message data code. Correspondingly, at the GPS signal receiver, to demodulate the navigation message data code from the received satellite signal, the baseband DSP must completely remove the carrier, including the Doppler shift, from the digital IF signal through mixing, and completely remove the C / A code from the signal through C / A code correlation. The remaining signal is the BPSK-modulated navigation message data code.

[0245] The tracking loop is used to track the GPS signal and continuously modulate the copied carrier inside it so that the phase of the copied carrier is consistent with the phase of the carrier in the digital intermediate frequency signal, thereby achieving carrier stripping.

[0246] Specifically, the tracking loop includes: a control circuit, a four-quadrant phase detector, a phase-locked loop, a loop filter, a voltage-controlled oscillator, and a first switch; wherein one end of the first switch is connected to the control circuit, and the other end is connected to the four-quadrant phase detector; the four-quadrant phase detector is connected to the loop filter and the voltage-controlled oscillator in sequence; when there is a navigation message to assist in tracking satellite signals, the control circuit controls the first switch to close, and uses the first tracking loop including the four-quadrant phase detector, the loop filter, and the voltage-controlled oscillator to track the satellite signals.

[0247] In addition, the tracking loop also includes: a two-quadrant phase detector and a second switch, one end of the second switch is connected to the control circuit, and the other end is connected to the two-quadrant phase detector; the two-quadrant phase detector is connected to the loop filter and the voltage-controlled oscillator in sequence; in the absence of navigation messages to assist in tracking satellite signals, the control circuit controls the second switch to close and the first switch to open, and tracks the satellite signal using the second tracking loop including the two-quadrant phase detector, the loop filter, and the voltage-controlled oscillator.

[0248] Microprocessor 1303 is used for differential positioning calculations to obtain accurate terminal device location information. Optionally, microprocessor 1303 includes a positioning and navigation module and at least one interface 1305. The positioning and navigation module, also known as the position calculation module, is primarily responsible for calculating the receiver's position, velocity, and time (PVT). After calculation, it reports position and velocity information to the terminal device's operating system via an interface. Optionally, interface 1305 is a Google interface.

[0249] In addition, the microprocessor 1303 may also include an inertial navigation module, which primarily uses sensors such as speedometers and accelerometers to interact with and assist the position calculation module, thereby further improving navigation performance. Common assistance methods include loose coupling, tight coupling, and deep coupling.

[0250] Optionally, the positioning chip 130 is a GNSS positioning chip.

[0251] Memory 1304 may include volatile memory, such as random access memory (RAM); non-volatile memory, such as flash memory, hard disk drive (HDD) or solid state drive (SSD); or a combination of the above types of memory. The memory may store programs or codes, and the microprocessor may implement the functions of the terminal device by executing the programs or codes. In addition, memory 1304 may exist independently or may be integrated with microprocessor 1303.

[0252] It should be understood that the positioning chip 130 can also be used as a processor. The processor can use various interfaces and lines to connect various parts of the entire terminal device, and execute various functions and / or process data of the terminal device by running or executing software programs and / or units stored in the memory 1304, and calling data stored in the memory 1304. Furthermore, the processor can be composed of an integrated circuit (IC), for example, it can be composed of a single packaged IC, or it can be composed of multiple packaged ICs with the same or different functions. For example, the processor can only include a combination of a central processing unit (CPU) and a control chip (such as a baseband chip) in a transceiver.

[0253] In addition, the terminal device may also include other more or fewer components, or a combination of certain components, or different components, which is not limited in the embodiments of the present application.

[0254] In this embodiment, when the terminal device is used as a GPS receiver, the above-mentioned embodiment can be realized. Figure 5 、 Figure 6 and Figure 9 The method steps shown, and the aforementioned Figure 10 In the illustrated embodiment, the functions of the transceiver circuit 41 may be implemented by the DSP 1302 and the antenna 2 , the functions to be implemented by the processing circuit 42 may be implemented by the DSP 1302 ; and the functions of the storage unit 43 may be implemented by the memory 1304 .

[0255] The method provided in this application integrates a DSP and a microprocessor in a GNSS positioning chip, thereby realizing satellite signal tracking and resolution on the positioning chip side, obtaining carrier phase measurement values, and determining whether a carrier phase cycle slip occurs from the recorded carrier phase tracking information. This method utilizes RTK technology for positioning calculations, has strong real-time performance, and has low algorithm complexity.

[0256] In addition, embodiments of the present application further provide a computer storage medium that can store a program that, when executed, can include some or all of the steps of each embodiment of the positioning method provided herein. The storage medium can be a magnetic disk, an optical disk, a read-only memory (ROM), or a random access memory (RAM).

[0257] In the above embodiments, all or part of the embodiments may be implemented by software, hardware, firmware, or any combination thereof. When implemented by software, all or part of the embodiments may be implemented in the form of a computer program product.

[0258] The computer program product includes one or more computer instructions, such as signal receiving instructions, signal tracking instructions, sending instructions, etc. When the computer loads and executes the computer program instructions, it generates all or part of the method flow or function described in the above-mentioned embodiments of this application.

[0259] The computer may be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions may be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another computer-readable storage medium. The computer-readable storage medium may be any available medium that a computer can access or a storage device such as a server or a data center that includes one or more available media integrations. The available medium may be a magnetic medium, such as a floppy disk, a hard disk, a magnetic tape, an optical medium (such as a DVD), or a semiconductor medium, such as a solid-state drive (SSD).

[0260] The terms "first," "second," and the like in the specification and claims of this application and the accompanying drawings are used to distinguish similar items and are not necessarily used to describe a particular order or precedence. In addition, the terms "include," "comprise," and any variations thereof are intended to cover non-exclusive inclusions.

[0261] In this specification, the same or similar parts between the various embodiments can be referred to each other. In particular, for the terminal equipment and apparatus, since they are basically similar to the method embodiment, the description is relatively simple, and the relevant parts can be referred to the description in the method embodiment.

[0262] The above-described embodiments of the present application do not constitute a limitation on the scope of protection of the present application.

Claims

1. A positioning method, characterized in that: The method is applied to a terminal device, the terminal device including a positioning chip and a system-on-chip (SoC) chip, and the method includes: The positioning chip receives a satellite signal transmitted by at least one satellite; The positioning chip performs synchronous detection on the satellite signal; After completing the synchronous detection, the positioning chip determines whether there is a navigation message to assist in tracking; The positioning chip tracks the satellite signal using a corresponding tracking loop based on the determination result of whether there is navigation message-assisted tracking, and obtains carrier phase tracking information of the satellite signal, wherein the carrier phase tracking information includes a carrier phase measurement value; The positioning chip determines whether a cycle slip and a half cycle slip occur in the carrier phase according to the carrier phase measurement value; The positioning chip obtains the differential correction amount sent by the reference station through the SoC chip, and the differential correction amount is used to correct the distance measurement value calculated based on the satellite signal; The positioning chip performs positioning calculation based on the carrier phase differential technology, using the carrier phase tracking information and the differential correction amount according to the judgment result of whether the carrier phase has a cycle slip and a half cycle slip; Wherein, if there is navigation message-assisted tracking, the satellite signal is tracked using a first tracking loop, wherein the first tracking loop includes a four-quadrant phase detector; if there is no navigation message-assisted tracking, the satellite signal is tracked using a second tracking loop, wherein the second tracking loop includes a two-quadrant phase detector; Wherein, if a half cycle jump occurs, phase compensation is performed on the carrier phase measurement value before positioning calculation is performed using the carrier phase tracking information and the differential correction amount.

2. The method according to claim 1, characterized in that The positioning chip performs positioning calculation based on the carrier phase differential technology using the carrier phase tracking information and the differential correction amount according to the judgment result of whether the carrier phase has a cycle slip and a half cycle slip, including: According to the judgment result of whether the carrier phase has cycle jump and half cycle jump, based on the carrier phase differential technology, the carrier phase tracking information and the differential correction amount are used to perform positioning calculation to obtain the location information of the terminal device.

3. The method according to claim 1, characterized in that The satellite signal transmitted by the at least one satellite includes a first satellite signal, The positioning chip tracks the satellite signal using a corresponding tracking loop based on the result of determining whether there is navigation message-assisted tracking, and obtains carrier phase tracking information of the satellite signal, including: If there is navigation message-assisted tracking, the first tracking loop is used to track the first satellite signal, and the first satellite signal outputs a first carrier phase measurement value after passing through the four-quadrant phase detector; The positioning chip determines whether a cycle slip and a half cycle slip occur in the carrier phase according to the carrier phase measurement value, including: determining whether a cycle slip occurs in the carrier phase according to the first carrier phase measurement value; The positioning chip performs positioning calculation based on the carrier phase differential technology using the carrier phase tracking information and the differential correction amount according to the judgment result of whether the carrier phase has a cycle slip and a half cycle slip, including: If no cycle slip occurs, a step of performing positioning calculation based on a carrier phase differential technique using the carrier phase tracking information and the differential correction amount is executed.

4. The method according to claim 3, characterized in that The positioning chip tracks the satellite signal using a corresponding tracking loop based on the result of determining whether there is navigation message-assisted tracking, and obtains carrier phase tracking information of the satellite signal, further comprising: If there is no navigation message to assist in tracking, the first satellite signal is tracked using a second tracking loop, and the first satellite signal outputs a second carrier phase measurement value after passing through the two-quadrant phase detector; The positioning chip determines whether a cycle slip and a half cycle slip occur in the carrier phase according to the carrier phase measurement value, including: determining whether a cycle slip occurs in the carrier phase according to the second carrier phase measurement value; The positioning chip performs positioning calculation based on the carrier phase differential technology using the carrier phase tracking information and the differential correction amount according to the judgment result of whether the carrier phase has a cycle slip and a half cycle slip, including: If no cycle slip occurs, querying the frame header of the navigation message on the demodulated first satellite signal to determine whether it is in phase with the actual navigation message frame header; If they are in phase, a step of performing positioning calculation based on carrier phase differential technology using the carrier phase tracking information and the differential correction amount is executed.

5. The method according to claim 4, characterized in that If a cycle slip does not occur, querying the frame header of the navigation message on the demodulated first satellite signal to determine whether it is in phase with the actual navigation message frame header, further comprising: If they are out of phase, performing phase compensation on the second carrier phase measurement value to obtain a third carrier phase measurement value; The carrier phase differential technology is based on which positioning calculation is performed using the carrier phase tracking information and the differential correction amount, including: Based on the carrier phase difference technology, positioning calculation is performed using the third carrier phase measurement value and the differential correction amount.

6. The method according to claim 1, wherein The satellite signal transmitted by the at least one satellite includes a second satellite signal, After completing the synchronous detection, the positioning chip includes: Tracking the second satellite signal using the first tracking loop to obtain carrier phase tracking information of the satellite signal, the carrier phase tracking information comprising a fourth carrier phase measurement value output by the second satellite signal after passing through the four-quadrant phase detector; The positioning chip determines whether a cycle slip occurs in the carrier phase according to the fourth carrier phase measurement value; If not, positioning calculation is performed based on the carrier phase difference technology using the carrier phase tracking information and the differential correction amount.

7. The method according to any one of claims 1 to 6, characterized in that After the positioning chip receives a satellite signal transmitted by at least one satellite, the method further includes: The positioning chip demodulates the satellite signal to obtain rough location information of the terminal device; The coarse position information is sent to the reference station, so that the reference station feeds back the differential correction amount according to the coarse position information.

8. The method according to claim 3, characterized in that The differential correction amount includes a carrier phase measurement value of a common view satellite signal, where the common view satellite signal is a satellite signal tracked jointly by the terminal device and the reference station; The step of performing positioning calculation based on carrier phase differential technology and using the carrier phase tracking information and the differential correction amount includes: Performing a differential calculation using the carrier phase measurement value of the common view satellite signal and the first carrier phase measurement value to obtain a first integral ambiguity; determining a corrected carrier phase measurement using the first integral ambiguity; Positioning calculation is performed based on the corrected carrier phase measurement value.

9. A positioning chip, characterized in that: The positioning chip includes: a transceiver circuit, configured to receive a satellite signal transmitted by at least one satellite; a processing circuit, configured to perform synchronous detection on the satellite signal; The processing circuit is further configured to determine whether there is navigation message-assisted tracking after completing the synchronization detection; The processing circuit is further configured to track the satellite signal using a corresponding tracking loop based on a determination result of whether navigation message-assisted tracking is available, and obtain carrier phase tracking information of the satellite signal, wherein the carrier phase tracking information includes a carrier phase measurement value; The processing circuit is further configured to determine whether a cycle slip or a half cycle slip occurs in the carrier phase according to the carrier phase measurement value; The processing circuit is further configured to obtain a differential correction value sent by a reference station through a system-on-chip (SoC) chip, wherein the differential correction value is used to correct a distance measurement value calculated based on the satellite signal; The processing circuit is further configured to perform positioning calculation based on a carrier phase differential technology using the carrier phase tracking information and the differential correction amount according to a result of determining whether a cycle slip and a half cycle slip occur in the carrier phase; Wherein, if there is navigation message-assisted tracking, the satellite signal is tracked using a first tracking loop, wherein the first tracking loop includes a four-quadrant phase detector; if there is no navigation message-assisted tracking, the satellite signal is tracked using a second tracking loop, wherein the second tracking loop includes a two-quadrant phase detector; Wherein, if a half cycle jump occurs, phase compensation is performed on the carrier phase measurement value before positioning calculation is performed using the carrier phase tracking information and the differential correction amount.

10. The positioning chip according to claim 9, characterized in that: The processing circuit specifically uses the carrier phase tracking information and the differential correction amount to perform positioning calculations to obtain the location information of the terminal device.

11. The positioning chip according to claim 9, characterized in that: The satellite signal transmitted by the at least one satellite includes a first satellite signal, The processing circuit is specifically configured to track the first satellite signal using the first tracking loop if there is navigation message-assisted tracking, and output a first carrier phase measurement value after the first satellite signal passes through the four-quadrant phase detector; The processing circuit is further configured to determine whether a cycle slip occurs in the carrier phase according to the first carrier phase measurement value; The processing circuit is further configured to, if no cycle slip occurs, execute a step of performing positioning calculation based on a carrier phase differential technique using the carrier phase tracking information and the differential correction amount.

12. The positioning chip according to claim 11, characterized in that: The processing circuit is further configured to track the first satellite signal using a second tracking loop if there is no navigation message to assist in tracking, and the first satellite signal outputs a second carrier phase measurement value after passing through the two-quadrant phase detector; The processing circuit is further configured to determine whether a cycle slip occurs in the carrier phase according to the second carrier phase measurement value; The processing circuit is further configured to query a frame header of the navigation message on the demodulated first satellite signal to determine whether the frame header is in phase with an actual navigation message frame header if a cycle slip does not occur; The processing circuit is further configured to execute the step of performing positioning calculation based on the carrier phase differential technology using the carrier phase tracking information and the differential correction amount if the phases are the same.

13. The positioning chip according to claim 12, characterized in that: The processing circuit is further configured to perform phase compensation on the second carrier phase measurement value when determining that the second carrier phase measurement value is out of phase with the actual navigation message frame header to obtain a third carrier phase measurement value; The processing circuit is specifically configured to perform positioning calculation based on a carrier phase differential technology using the third carrier phase measurement value and the differential correction amount.

14. The positioning chip according to claim 9, characterized in that: The satellite signal transmitted by the at least one satellite includes a second satellite signal, The processing circuit is specifically configured to, after completing the synchronization detection, track the second satellite signal using the first tracking loop to obtain carrier phase tracking information of the satellite signal, the carrier phase tracking information comprising a fourth carrier phase measurement value output by the second satellite signal after passing through the four-quadrant phase detector; The processing circuit is further configured to determine whether a cycle slip occurs in the carrier phase according to the fourth carrier phase measurement value; The processing circuit is further configured to, if not, perform positioning calculation based on carrier phase differential technology using the carrier phase tracking information and the differential correction amount.

15. The positioning chip according to any one of claims 9 to 14, characterized in that: The processing circuit is further configured to, after receiving a satellite signal transmitted by at least one satellite, demodulate the satellite signal to obtain rough location information of the terminal device; The transceiver circuit is further configured to send the coarse position information to the reference station, so that the reference station feeds back the differential correction amount according to the coarse position information.

16. The positioning chip according to claim 11, characterized in that: The differential correction amount includes a carrier phase measurement value of a common view satellite signal, where the common view satellite signal is a satellite signal tracked jointly by the positioning chip and the reference station; The processing circuit is specifically used to perform a differential calculation using the carrier phase measurement value of the common view satellite signal and the first carrier phase measurement value to obtain a first cycle ambiguity, determine a corrected carrier phase measurement value using the first cycle ambiguity; and perform positioning calculation based on the corrected carrier phase measurement value.

17. A tracking loop, characterized in that include: control circuit, a four-quadrant phase detector, a phase-locked loop, a loop filter, a voltage-controlled oscillator and a first switch, and a two-quadrant phase detector and a second switch; wherein, One end of the first switch is connected to the control circuit, and the other end is connected to the four-quadrant phase detector; The four-quadrant phase detector is connected to the loop filter and the voltage-controlled oscillator in sequence; One end of the second switch is connected to the control circuit, and the other end is connected to the two-quadrant phase detector; The two-quadrant phase detector is connected to the loop filter and the voltage-controlled oscillator in sequence; The control circuit controls the first switch to close when there is a navigation message to assist in tracking the satellite signal, and tracks the satellite signal using a first tracking loop including the four-quadrant phase detector, the loop filter, and the voltage-controlled oscillator; In the absence of navigation messages to assist in tracking satellite signals, the control circuit controls the second switch to be closed and the first switch to be open, and tracks the satellite signals using a second tracking loop including the two-quadrant phase detector, the loop filter, and the voltage-controlled oscillator.

18. A terminal device, characterized in that: include: Positioning chips and system-on-chip SoC chips, The SoC chip is used to send a differential correction value from a reference station to the positioning chip, where the differential correction value is used to correct the distance measurement value calculated based on the satellite signal; The positioning chip includes a processing circuit, and when the processing circuit executes a computer program stored in a memory, the method according to any one of claims 1 to 8 is implemented.

19. A computer-readable storage medium comprising instructions, which, when executed on a computer, cause the computer to perform the method according to any one of claims 1 to 8.

20. A computer program product which, when run on a computer, causes the computer to perform the method according to any one of claims 1 to 8.

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