A master-slave station synchronous tracking method, device, equipment and computer readable storage medium

Abstract

The application provides a master-slave station synchronization tracking method and device, equipment and a computer readable storage medium, acquires a ranging result sent by a master station; determines a first measured pseudo-range according to the ranging result; calculates a difference value between the first measured pseudo-range and a second measured pseudo-range; wherein the second measured pseudo-range is a measured pseudo-range determined according to a last ranging result; and based on the difference value, synchronously tracks a frequency control word and an initial phase of the master station clock. Through implementation of the application scheme, the first measured pseudo-range is determined according to the ranging result sent by the master station, and the difference value between the first measured pseudo-range and the last measured pseudo-range is calculated, and based on the difference value, the frequency control word and the initial phase of the master station clock are synchronously tracked through a synchronous tracking algorithm, which can effectively improve the accuracy of time and frequency tracking of a slave station.

Description

Technical Field

[0001] This application relates to the field of clock synchronization technology, and in particular to a master-slave station synchronization tracking method, apparatus, device, and computer-readable storage medium. Background Technology

[0002] A precise timing synchronization system typically consists of a bistatic time-base system synchronization module comprising one master station and one, two, or more slave stations. Each station synchronizes its time during data communication. The entire communication system is used to achieve high-precision positioning and timing between aircraft. However, during the output of clock signals from the master and slave stations, because the master station does not adjust the clock frequency control word, the slave stations need to continuously correct the frequency control word to maintain consistency with the master station's time and frequency. Therefore, it is crucial to derive an optimal correction algorithm to ensure that the slave stations maintain precise synchronization and tracking of the master station's time and frequency. Summary of the Invention

[0003] This application provides a master-slave station synchronization tracking method, apparatus, device, and computer-readable storage medium, which can at least solve the problem in the related art that the slave station cannot accurately synchronize and track the master station's time and frequency when the master station does not adjust the clock frequency control word.

[0004] The first aspect of this application provides a master-slave station synchronization tracking method, including:

[0005] Obtain the ranging results sent by the main station;

[0006] Determine the first measurement pseudorange based on the ranging results;

[0007] Calculate the difference between the first measurement pseudorange and the second measurement pseudorange; wherein the second measurement pseudorange is the measurement pseudorange determined by the previous ranging result;

[0008] Based on the difference, the frequency control word and initial phase of the master station clock are synchronized and tracked.

[0009] Optionally, the step of obtaining the ranging result sent by the master station includes:

[0010] Upon receiving a ranging frame sent by the master station, the first starting position time of the ranging frame is determined by the local correlation code;

[0011] When the ranging frame is sent to the master station, the second starting position time when the master station receives the ranging frame is determined by the local correlation code;

[0012] When the master station calculates the distance using the ranging formula, the ranging result sent by the master station is obtained.

[0013] Optionally, the ranging result includes an integer part and a fractional part of the sampling period, and the expression for determining the first measurement pseudorange based on the ranging result is:

[0014] T F =nT s +τ,

[0015] Among them, T F For the measured pseudorange, T s The sampling period is τ, and the fractional part is τ.

[0016] Optionally, before the step of determining the first measurement pseudorange based on the ranging result, the method further includes:

[0017] The integer part is determined based on the optimal sampling point and the correlation value of two adjacent points;

[0018] The fractional part is calculated based on the optimal sampling point and the correlation values ​​of two adjacent points.

[0019] Optionally, the expression for calculating the difference between the first measurement pseudorange and the second measurement pseudorange is: ΔT F (i)=T F (i)-T F (i-1),

[0020] Where i is the corresponding round for measuring the pseudorange, and ΔT F (i) is the difference.

[0021] Optionally, if the actual distance between the master and slave stations remains unchanged, the step of synchronizing and tracking the frequency control word and initial phase of the master station clock based on the difference includes:

[0022] When the difference in the measured pseudorange is not equal to zero, the step size of the frequency control word is adjusted based on the first adjustment step coefficient; wherein, the adjustment formula of the frequency control word is:

[0023] FCW 调 =FCW±ΔFCW0,

[0024] The FCW is the frequency control word, and ΔFCW0 is the adjustment step.

[0025] When the difference is adjusted to a preset threshold range, the step size of the frequency control word is adjusted based on the second adjustment step coefficient, and the initial phase value is adjusted according to the ranging value of the fractional part; wherein, the adjustment formula for the initial phase value is: PHS 调 =PHS±ΔPHS,

[0026] The PHS is the initial phase value, and the ΔPHS is the adjustment step of the initial phase value.

[0027] Optionally, after the steps of adjusting the step size of the frequency control word based on the second adjustment step coefficient and adjusting the initial phase value according to the ranging value of the fractional part, the method further includes:

[0028] Acquire the ranging value during tracking;

[0029] If the ranging value fluctuates within the preset fluctuation range, then it is determined that the synchronization tracking of the frequency control word and initial phase of the master station clock is completed.

[0030] A second aspect of this application provides a master-slave station synchronization tracking device, comprising:

[0031] The acquisition module is used to acquire the ranging results sent by the main station;

[0032] The determining module is used to determine a first measurement pseudorange based on the ranging result;

[0033] The calculation module is used to calculate the difference between the first measurement pseudorange and the second measurement pseudorange; wherein the second measurement pseudorange is the measurement pseudorange determined by the previous ranging result;

[0034] The tracking module is used to synchronize and track the frequency control word and initial phase of the master station clock based on the difference.

[0035] A third aspect of this application provides an electronic device, characterized in that it includes a memory and a processor, wherein the processor is configured to execute a computer program stored in the memory, and the processor executes the computer program in the steps of the master-slave station synchronization tracking method provided in the first aspect of the embodiments of this application described above.

[0036] The fourth aspect of this application provides a computer-readable storage medium having a computer program stored thereon, wherein when the computer program is executed by a processor, it implements the steps of the master-slave station synchronization tracking method provided in the first aspect of the embodiments of this application.

[0037] As can be seen from the above, according to the master-slave station synchronization tracking method, apparatus, device, and computer-readable storage medium provided in this application, the ranging result sent by the master station is obtained; a first measurement pseudorange is determined based on the ranging result; the difference between the first measurement pseudorange and the second measurement pseudorange is calculated; wherein, the second measurement pseudorange is the measurement pseudorange determined by the previous ranging result; and based on the difference, the frequency control word and initial phase of the master station clock are synchronized and tracked. Through the implementation of this application, the first measurement pseudorange is determined based on the ranging result sent by the master station, and the difference between it and the previous measurement pseudorange is calculated. Based on this difference, the frequency control word and initial phase of the master station clock are synchronized and tracked using a synchronization tracking algorithm, which can effectively improve the accuracy of time-frequency tracking by the slave station. Attached Figure Description

[0038] Figure 1 A basic flowchart illustrating the master-slave station synchronization tracking method provided in this application embodiment;

[0039] Figure 2 This is a schematic diagram of the ranging timing provided in the embodiments of this application;

[0040] Figure 3 A schematic diagram of the optimal sampling point and three points on both sides of it provided in the embodiments of this application on the time-domain waveform diagram;

[0041] Figure 4 This application provides a schematic diagram of the principle of a high-precision digital frequency synthesizer in an embodiment.

[0042] Figure 5 The delay test loop diagram provided in the embodiments of this application;

[0043] Figure 6 A schematic diagram of clock-bias-free high signal-to-noise ratio ranging values ​​provided in the embodiments of this application;

[0044] Figure 7 A schematic diagram of the clock-bias-free, low signal-to-noise ratio ranging values ​​provided in the embodiments of this application;

[0045] Figure 8 A schematic diagram of a high signal-to-noise ratio ranging value with clock error provided in an embodiment of this application;

[0046] Figure 9 A schematic diagram of a ranging value with low signal-to-noise ratio and clock bias provided in an embodiment of this application;

[0047] Figure 10 A schematic diagram of the program modules of the master-slave station synchronization tracking device provided in the embodiments of this application;

[0048] Figure 11 This is a schematic diagram of the structure of an electronic device provided in an embodiment of this application. Detailed Implementation

[0049] To make the inventive objectives, features, and advantages of this application more apparent and understandable, the technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0050] To address the problem in related technologies where the slave station cannot accurately synchronize and track the master station's time and frequency when the master station does not adjust the clock frequency control word, this application provides a master-slave station synchronization tracking method, such as... Figure 1This is a basic flowchart of the master-slave synchronization tracking method provided in this embodiment. The master-slave synchronization tracking method includes the following steps:

[0051] Step 110: Obtain the ranging results sent by the main station.

[0052] Specifically, the synchronization process between the master and slave stations mainly consists of two parts: pseudocode acquisition and network entry tracking. Pseudocode acquisition: The master station sends pseudocode, the slave station acquires it and enters the network, the master station performs ranging, and the slave station performs time slot synchronization. Network entry tracking: After acquisition and network entry, the master and slave stations only complete time synchronization of communication. They also need to perform time synchronization (including coarse and fine synchronization) and frequency synchronization (frequency offset estimation and correction) on the received downlink signals. System synchronization relies on the transmission and reception of pseudocode for estimation. After the master and slave stations are powered on, they each complete time delay self-calibration. The master station sends pseudocode information, and the slave station uses the same pseudocode for synchronous scanning. When relevant peak power points appear, the location of the indication information is determined, and the indication information is parsed. If the slave ID number in the indication information matches the master station's ID, a ranging signal is sent to the master station at a pre-set location. The master station receives the ranging signal, determines that the slave ID matches the sent ID, and considers the slave station to have successfully entered the network. Simultaneously, the master station informs the slave station of the time advance, and the slave station will send data in advance according to this ranging amount. In this embodiment, after the master station is powered on, it sends pseudo-code according to the frame structure, and each slave station is in normal receiving state. The ranging ground station calculates the ranging information based on the synchronization feedback instruction received from the airborne station and transmits the ranging result to the airborne station. This data is actually the transmission delay between the ground station and the corresponding master airborne station.

[0053] In one optional implementation of this embodiment, the step of obtaining the ranging result sent by the master station includes: when receiving the ranging frame sent by the master station, determining the first starting position time of the ranging frame through the local correlation code; when sending the ranging frame to the master station, determining the second starting position time of the master station receiving the ranging frame through the local correlation code; and when the master station calculates the distance using the ranging formula, obtaining the ranging result sent by the master station.

[0054] Specifically, the relationship between master and slave stations includes, but is not limited to, the master-slave relationship between the ground station and the host machine, and the master-slave relationship between the host machine and the slave machine. In this embodiment, for example... Figure 2 The diagram shown is a timing sequence diagram of ranging provided in an embodiment of this application. Taking the ground as the master station and the corresponding host as the slave station as an example, the ground sends a ranging frame to the airborne station in slot 0. The start time of the ranging frame data transmission is the time of slot 0. After spatial propagation, the airborne station receives the ranging frame and obtains the start time α1 of the frame through the local correlation code. Then, it delays the time by one slot 0 time t. slot0 Starting from position t1, a ranging frame is returned to the ground in slot 1; at this time, t1 = α1 + t slot0Through spatial propagation, after receiving the frame, the ground also obtains the time α2 of the start position of receiving the frame through correlation, at which point t2=t1+α2=α1+α2+t slot0 The calculated distance value is L = C * (t² - t). slot0 After the master station calculates the ranging information, it transmits the ranging results to the slave station.

[0055] Optionally, theoretically, correlation calculations can only obtain the integer position of the starting time. This means that demodulation in the receiving link can acquire data starting from this correlation value. However, for ranging, a 10ns difference between two correlation values ​​represents a 3-meter distance error, which does not meet the 1-meter requirement. Therefore, it is necessary to interpolate the time within the 10ns range to a higher precision to obtain the theoretical correlation value. This near-true ranging parameter is then transmitted, which can be divided into an integer part and a fractional part. The integer and fractional parts are transmitted to their respective airborne components, allowing the airborne system to determine the distance to the ground based on the time delays of the integer and fractional parts.

[0056] Step 120: Determine the first measurement pseudorange based on the ranging results.

[0057] Specifically, in this embodiment, the ranging result includes two parts: the integer part of the sampling period nT. s And the decimal part τ. The ranging result is obtained by correlating the optimal sampling points, and this correlation value is only an approximation, not an exact value. Therefore, the ranging result obtained by correlation can be understood as a measurement pseudorange, the measurement pseudorange T. F It equals the integer part of the distance measurement plus the decimal part, i.e., T. F =nT s +τ.

[0058] Optionally, the integer part is determined based on the correlation values ​​of the optimal sampling point and two adjacent points; the decimal part is calculated based on the correlation values ​​of the optimal sampling point and two adjacent points. In this embodiment, the integer part of the ranging result is determined by tracking the correlation values ​​of the optimal sampling point and the two points to its left and right, which is generally considered to be very accurate. The decimal part needs to be estimated using an algorithm, which can be done by using the correlation values ​​of the optimal sampling point and the three points on either side of it.

[0059] like Figure 3 The diagram shows the optimal sampling point and three points on either side of it in the time domain waveform. In the diagram, T represents the chip period. sLet τ be the sampling period, and τ be the time difference between the actual optimal sampling point and the optimal sampling point obtained during acquisition. If the actual optimal sampling point is before the optimal sampling point obtained during acquisition, then τ is negative; otherwise, τ is positive. It is understandable that the actual optimal sampling point cannot be accurately obtained, therefore τ is a quantity that needs to be estimated based on the relevant algorithm. If the received signal is r(n) and the pseudocode sent by the host is p(n), then the expression for the relevant process is:

[0060]

[0061] Where R represents the correlation value of the corresponding point on the time-domain waveform graph.

[0062] In this embodiment, the sampling period T s =T / 10, based on Figure 3 The distribution of the three points, according to the isosceles triangle formula, is expressed as the time difference between the normalized actual optimal sampling point and the optimal sampling point obtained during acquisition, as follows:

[0063]

[0064] Where R1 is Figure 3 The correlation value at point P1, R2 is the correlation value at the optimal sampling point P2, and R3 is the correlation value at point P3. Since the sampling period T... s Since the quantity is known, the measurement pseudorange T can be calculated by combining this formula with the relevant process expressions mentioned above. F The decimal part τ.

[0065] Step 130: Calculate the difference between the first measurement pseudorange and the second measurement pseudorange.

[0066] Specifically, the second measurement pseudorange is the measurement pseudorange determined by the previous ranging result. Before the slave station synchronizes with the master station's time and frequency, it needs to determine whether the measurement pseudorange has changed. If the measurement pseudorange has changed, it needs to synchronize with the master station's clock frequency control word and initial phase based on the difference. If the measurement pseudorange has not changed, it means that the slave station's time and frequency are consistent with the master station's time and frequency.

[0067] Optionally, the expression for calculating the difference between the first and second measurement pseudoranges is as follows:

[0068] ΔT F (i)=T F (i)-T F (i-1),

[0069] Where i is the corresponding round for measuring the pseudorange, and ΔT F (i) represents the difference between the first measurement pseudorange and the second measurement pseudorange.

[0070] Step 140: Based on the difference, synchronize and track the frequency control word and initial phase of the master station clock.

[0071] Specifically, in this embodiment, when the slave station adjusts the frequency control word FCW and the initial phase PHS, it does so in two steps. Initially, the transmit and receive clock frequency difference P... cs The error could be significant, requiring a relatively large step size for adjustment to quickly bring the clock bias to near zero, without adjusting the initial phase value. When adjusting the FCW from the slave station, each adjustment is based on a fixed step factor C. FO (C FO =1 / 2 28 That is, to increase or decrease the value of ΔFCW0, ΔFCW0 = FCW × C FO When the actual master-slave distance remains unchanged, when ΔT F When (i) > 0, it means the local clock is fast and needs to be slowed down. The corresponding adjustment expression is:

[0072] FCW 调 =FCW-ΔFCW0,

[0073] This adjustment is based on the premise that the distance between the two tests remains unchanged, and the difference in pseudorange is solely due to clock jitter. If the measured ΔT... F If (i) > 0 and becomes longer, it indicates that the clock is jumping faster and needs to be slowed down. Otherwise, it means the local clock is slow and needs to be sped up.

[0074] FCW 调 =FCW+ΔFCW0,

[0075] After a period of large-step adjustments, it transitions to tracking mode, and the adjustment step factor of FCW changes to C. FO (C FO =1 / 2 33 The adjustment method is the same as the initial adjustment, and the initial phase value adjustment begins. The initial phase value is adjusted based on the fractional part of the ranging value τ(i), with an adjustment step of ΔPHS. If τ(i) ≥ 0, the phase value is adjusted by decreasing one step.

[0076] PHS 调 =PHS-ΔPHS,

[0077] Otherwise, adjust the phase value by one step.

[0078] PHS 调 =PHS-ΔPHS,

[0079] By making a final adjustment so that the fractional part of the ranging value τ(i) approaches 0, the tracking of the start time of the transmitted frame can be achieved.

[0080] Optionally, firstly, when the stability of the crystal oscillator is Pcs =10e -12 At that time, the stability of other output clocks from the same source is 10e. -12 The stability remains unchanged, except for a slight deterioration in phase noise, which depends on factors such as device characteristics and the bandwidth of the loop filter. Generally speaking, the impact of phase noise is negligible. It's understandable that the stability of the crystal oscillator reflects the timekeeping error over a period of time. The slave station's ranging is performed according to the frame structure with a period ΔT. The maximum time error caused by the difference between the transmit and receive clocks within ΔT is Δτ = 2ΔTP. cs When ΔT = 1s, Δτ = 2P cs This value is very small. When adjusting FCW from the slave station, a fixed step can be taken each time, i.e., increasing or decreasing the value of ΔFCW. The key is to ensure that the amount of FCW adjustment each time keeps pace with the clock changes, i.e., ΔFCW / FCW > 2P. cs Furthermore, the resulting changes do not affect the ranging parameters. For example, when ΔT = 1s, ΔFCW = FCW / 233 = 1.16e can be set. -10 Greater than 2*10e -12 Furthermore, the maximum accumulated time error within the time interval ΔT is Δτ = 0.116 ns, which is very small. When ΔT is relatively small, the accumulated Δτ in a single instance is very small, but as time accumulates, the time error will become larger and larger. Therefore, the slave station needs to adjust its own clock frequency to track the master station's clock.

[0081] Optionally, the frequency stability of the clock selected in this embodiment is 10. -13 / s, when the frequency is multiplied to 100MHz, the frequency deviation is 100M*10 -13 That is, 10 -5 Hz / s. The time introduced by the clock's own frequency deviation is 10 times that of one clock cycle. -5 The time error of the crystal oscillator is 10ns*10. -5 That is, 0.1 ps. The algorithm requires a stability of 0.01 Hz when calculating the initial phase, which means a stability requirement of 0.01 / 100M, or 10... -10 / s, therefore, when selecting a crystal oscillator, a stability better than 10 is required. -11 / s, this condition is also met.

[0082] The clock used for time synchronization is manufactured internally within a high-precision phase-locked loop, and its input frequency originally had a stability specification of 10 Hz. -13 A high-stability crystal oscillator with a frequency of / s is used. During this period, the high-stability crystal oscillator is used as the input reference source. Internally, the required frequency is generated through a high-frequency clock and a high-precision digital frequency synthesizer. The implementation principle is as follows: Figure 4As shown in the schematic diagram of the high-precision digital frequency synthesizer provided in this application embodiment, the high-precision digital frequency synthesizer module uses a 48-bit accumulator and generates a digital sine wave through a digital frequency control word. The relationship between the frequency control word and the output frequency is as follows:

[0083]

[0084] That is, the output frequency is

[0085]

[0086] The internal frequency fs of the frequency synthesizer can be set to 1GHz, thus achieving a frequency resolution of 3.6µHz. It's understandable that FTW (Frequency Tuning Word) and FCW (Frequency Control Word) are both frequency control words, and both express the same meaning.

[0087] The 100MHz clock used for time synchronization has a selected frequency stability of 10. -13 The reference frequency, at a current of / s, is multiplied to 1GHz and obtained by a high-precision digital frequency synthesizer. Therefore, its frequency stability depends on the stability of the phase-locked loop output. This can be understood as a negative feedback control system that uses a voltage generated by phase synchronization to tune a voltage-controlled oscillator to generate a target frequency. The frequency and phase of the internal oscillation signal are controlled by an externally input reference signal, achieving automatic tracking of the output signal frequency to the input signal frequency.

[0088] In the time synchronization algorithm, the synchronization information update speed is approximately 200ms, the reference clock is 100MHz, and the period is 10ns. During clock synchronization, the PPS outputs once per second to synchronize the airborne system with the ground clock. The synchronization continues until the clock frequency reaches an accuracy of 10... -5 At Hz / s, i.e. 10 5 The time difference is only 1 pps. Therefore, during the synchronization information update process, it is only necessary to keep the host load frequency deviation within 10. -10 The requirement can be met by a second-level stability index, and the output frequency of the phase-locked loop is stable at 10 Hz. -11 Level. Therefore, it can meet the requirements for time synchronization.

[0089] Optionally, link latency can also affect the accuracy of time synchronization, which needs to be obtained in advance through factory testing during calculation. Because the master and slave stations need to compensate for the latency difference during transmission, including device transmission latency and spatial latency, during 1pps time synchronization, the more accurate the latency calculations of each component are, the better. Currently, a phase accumulator is used to synchronize the master's time. When updating the accumulator phase, device hardware latency and spatial distance need to be considered. Spatial latency is also the basis for positioning. Therefore, this embodiment describes the calculation process of device latency and positioning, and the data link device signal processing and transmission process are as follows. Figure 5 As shown, Figure 5 The latency test loop diagram provided in this application embodiment shows that the latency between the master and slave devices is TALL = T1 + T2 + 2 * T3, where T1 is the loopback latency of the ground equipment, T2 is the loopback time of the airborne equipment, T3 is the spatial latency, and TALL is the transmit / receive latency, which is consistent with the latency during ranging. According to the system scheme, the time synchronization system needs to calculate T1, T2, and T3, where T1 and T2 are the loopback times of the two devices respectively. Here, the clock period T is used as the time unit. Therefore, the latency correction process is divided into two parts: device self-calibration and master-slave calibration. First, device self-calibration refers to the closed-loop link formed by the interconnected transceiver ends of the devices themselves, such as... Figure 5 The ground and airborne systems each perform equipment delay calculations, and the calculation process is the same. In the transmission state, the transmission channel is coupled to the receiving channel through a circulator and a high-power switch. At this time, switch S1 is turned on to port A and switch S2 is turned on to port C, thus forming a loop T1 from the transmission to the receiving link. This loop contains all the processing procedures of the transmission link and the receiving link. Figure 5 The middle arrow indicates the direction of signal flow, and the ground obtains the delay T1 in the current state. Similarly, the airborne system obtains the self-calibration processing delay T2 in the same way, and the total spatial delay T3 = (TALL - T1 - T2) / 2.

[0090] In one optional implementation of this embodiment, after the steps of adjusting the step of the frequency control word based on the second adjustment step coefficient and adjusting the initial phase value according to the ranging value of the fractional part, the method further includes: obtaining the ranging value during tracking; if the ranging value fluctuates within a preset fluctuation range, then it is determined that the synchronous tracking of the frequency control word and the initial phase of the master station clock is completed.

[0091] Specifically, in this embodiment, the preset fluctuation range is ±2ns. The initial clock bias is set to -0.8e. -6 With an initial decimal distance of -5 ns, a clock bias rate of 0, and a signal-to-noise ratio of 10 dB, the distance estimate is as follows: Figure 6 As shown in the schematic diagram of the clock-bias-free high signal-to-noise ratio ranging value provided in the embodiments of this application, by Figure 6 As can be seen, after the initial fast convergence, the ranging value during tracking fluctuates around 0. Since the sampling rate of the transmission during the simulation is 1 GHz, the time resolution that can be represented is 1 ns. Therefore, the setting value of the ranging value can only be an integer ns, so the fluctuation will be ±1 ns.

[0092] The initial clock bias is set to -0.8e. -6 With an initial fractional distance of -5 ns, a clock bias rate of 0, and a signal-to-noise ratio of -5 dB, the distance estimate is as follows: Figure 7 As shown in the schematic diagram of the clock-bias-free, low signal-to-noise ratio ranging value provided in the embodiments of this application, by Figure 7 It can be seen that under low signal-to-noise ratio, after initial fast convergence, the ranging value during tracking still fluctuates around 0, but the fluctuation variance increases significantly, which is due to the influence of noise.

[0093] The initial clock bias is set to -0.8e. -6 The initial fractional part distance is -5 ns, and the clock error rate is 1 m / s. 2 When the signal-to-noise ratio is 10dB, the distance estimate is as follows: Figure 8 As shown in the schematic diagram of the high signal-to-noise ratio ranging value with clock bias provided in the embodiments of this application, by Figure 8 It can be seen that when there is dynamics, after the initial fast convergence, the ranging value during tracking still fluctuates around 0, indicating that tracking can be completed.

[0094] The initial clock bias is set to -0.8e. -6 The initial fractional part distance is -5 ns, and the clock error rate is 1 m / s. 2 When the signal-to-noise ratio is -5dB, the distance estimate is as follows: Figure 9 As shown in the schematic diagram of the ranging value with low signal-to-noise ratio and clock bias provided in the embodiments of this application, by Figure 9 It can be seen that when there is a dynamic low signal-to-noise ratio, after the initial fast convergence, the ranging value during tracking still fluctuates around 0, indicating that tracking can be completed.

[0095] Based on the embodiments of the above application, the ranging result sent by the master station is obtained; a first measurement pseudorange is determined according to the ranging result; the difference between the first measurement pseudorange and the second measurement pseudorange is calculated; wherein, the second measurement pseudorange is the measurement pseudorange determined by the previous ranging result; based on the difference, the frequency control word and initial phase of the master station clock are synchronously tracked. Through the implementation of this application's solution, the first measurement pseudorange is determined according to the ranging result sent by the master station, and the difference between it and the previous measurement pseudorange is calculated. Based on this difference, the frequency control word and initial phase of the master station clock are synchronously tracked using a synchronization tracking algorithm, which can effectively improve the accuracy of time-frequency tracking by the slave station.

[0096] Figure 10This application provides a master-slave station synchronization tracking device, which can be used to implement the master-slave station synchronization tracking method described in the foregoing embodiments. For example... Figure 10 As shown, the master-slave synchronous tracking device mainly includes:

[0097] The acquisition module 10 is used to acquire the ranging results sent by the main station;

[0098] Module 20 is used to determine the first measurement pseudorange based on the ranging results;

[0099] The calculation module 30 is used to calculate the difference between the first measurement pseudorange and the second measurement pseudorange; wherein the second measurement pseudorange is the measurement pseudorange determined by the previous distance measurement result;

[0100] The tracking module 40 is used to synchronously track the frequency control word and initial phase of the master station clock based on the difference.

[0101] In one optional implementation of this embodiment, the acquisition module is specifically used to: determine the first starting position time of the ranging frame by means of a local correlation code when receiving the ranging frame sent by the master station; determine the second starting position time of the master station receiving the ranging frame by means of a local correlation code when sending the ranging frame to the master station; and acquire the ranging result sent by the master station when the master station calculates the distance using the ranging formula.

[0102] In one optional implementation of this embodiment, the determining module is used to: determine the integer part based on the optimal sampling point and the correlation values ​​of two adjacent points. The calculating module is used to: calculate the decimal part based on the optimal sampling point and the correlation values ​​of two adjacent points.

[0103] In one optional implementation of this embodiment, the tracking module is specifically used to: adjust the step size of the frequency control word based on a first adjustment step coefficient when the difference between the measured pseudoranges is not equal to zero; wherein, the adjustment formula for the frequency control word is: FCW 调 =FCW±ΔFCW0,

[0104] FCW is the frequency control word, and ΔFCW0 is the adjustment step.

[0105] When the difference is adjusted to within a preset threshold range, the step size of the frequency control word is adjusted based on the second adjustment step coefficient, and the initial phase value is adjusted according to the decimal part of the ranging value; wherein, the adjustment formula for the initial phase value is:

[0106] PHS 调 =PHS±ΔPHS,

[0107] PHS is the initial phase value, and ΔPHS is the adjustment step of the initial phase value.

[0108] Furthermore, in an optional implementation of this embodiment, the acquisition module is further configured to: acquire the ranging value during tracking. The determination module is further configured to: if the ranging value fluctuates within a preset fluctuation range, determine that the synchronization tracking of the frequency control word and initial phase of the master station clock is complete.

[0109] According to the master-slave station synchronization tracking device provided in this application, the ranging result sent by the master station is obtained; a first measurement pseudorange is determined based on the ranging result; the difference between the first measurement pseudorange and the second measurement pseudorange is calculated; wherein the second measurement pseudorange is the measurement pseudorange determined by the previous ranging result; based on the difference, the frequency control word and initial phase of the master station clock are synchronized and tracked. Through the implementation of this application, the first measurement pseudorange is determined based on the ranging result sent by the master station, and the difference between it and the previous measurement pseudorange is calculated. Based on this difference, the frequency control word and initial phase of the master station clock are synchronized and tracked using a synchronization tracking algorithm, which can effectively improve the accuracy of time-frequency tracking by the slave station.

[0110] Figure 11 An electronic device is provided as an embodiment of this application. This electronic device can be used to implement the master-slave station synchronization tracking method described in the foregoing embodiments, and mainly includes:

[0111] The system includes a memory 1101, a processor 1102, and a computer program 1103 stored on the memory 1101 and executable on the processor 1102. The memory 1101 and the processor 1102 are connected via communication. When the processor 1102 executes the computer program 1103, it implements the master-slave station synchronization tracking method described in the previous embodiment. The number of processors can be one or more.

[0112] The memory 1101 can be a high-speed random access memory (RAM) or a non-volatile memory, such as a disk storage device. The memory 1101 is used to store executable program code, and the processor 1102 is coupled to the memory 1101.

[0113] Furthermore, embodiments of this application also provide a computer-readable storage medium, which may be disposed in the electronic device described in the above embodiments, and the computer-readable storage medium may be as described above. Figure 11 The memory in the illustrated embodiment.

[0114] The computer-readable storage medium stores a computer program that, when executed by a processor, implements the master-slave station synchronization tracking method described in the preceding embodiments. Furthermore, the computer-readable storage medium can also be a USB flash drive, external hard drive, read-only memory (ROM), RAM, magnetic disk, or optical disk, or any other medium capable of storing program code.

[0115] In the several embodiments provided in this application, it should be understood that the disclosed apparatus and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of modules is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple modules or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces; the indirect coupling or communication connection between apparatuses or modules may be electrical, mechanical, or other forms.

[0116] The modules described as separate components may or may not be physically separate. Similarly, the components shown as modules may or may not be physical modules; they may be located in one place or distributed across multiple network modules. Some or all of the modules can be selected to achieve the purpose of this embodiment, depending on actual needs.

[0117] Furthermore, the functional modules in the various embodiments of this application can be integrated into one processing module, or each module can exist physically separately, or two or more modules can be integrated into one module. The integrated modules described above can be implemented in hardware or as software functional modules.

[0118] If the integrated module is implemented as a software functional module and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a readable storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods of the various embodiments of this application. The aforementioned readable storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, ROM, RAM, magnetic disks, or optical disks.

[0119] It should be noted that, for the sake of simplicity, the foregoing method embodiments are all described as a series of actions. However, those skilled in the art should understand that this application is not limited to the described order of actions, as some steps may be performed in other orders or simultaneously according to this application. Furthermore, those skilled in the art should also understand that the embodiments described in the specification are preferred embodiments, and the actions and modules involved are not necessarily essential to this application.

[0120] In the above embodiments, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions of other embodiments.

[0121] The above is a description of the master-slave station synchronization tracking method, apparatus, device, and computer-readable storage medium provided in this application. For those skilled in the art, based on the ideas of the embodiments of this application, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of this application.

Claims

1. A master-slave station synchronization tracking method, characterized in that, include: Obtain the ranging results sent by the main station; Determine the first measurement pseudorange based on the ranging results; Calculate the difference between the first measurement pseudorange and the second measurement pseudorange; wherein the second measurement pseudorange is the measurement pseudorange determined by the previous ranging result; The ranging result includes the integer part and the fractional part of the sampling period. The expression for determining the first measurement pseudorange based on the ranging result is: ， Among them, T F For the measured pseudorange, T s The sampling period is τ, and the fractional part is τ. Based on the difference, the frequency control word and initial phase of the master station clock are synchronized and tracked.

2. The master-slave station synchronization tracking method according to claim 1, characterized in that, The step of obtaining the ranging results sent by the main station includes: Upon receiving a ranging frame sent by the master station, the first starting position time of the ranging frame is determined by the local correlation code; When the ranging frame is sent to the master station, the second starting position time when the master station receives the ranging frame is determined by the local correlation code; When the master station calculates the distance using the ranging formula, the ranging result sent by the master station is obtained.

3. The master-slave station synchronization tracking method according to claim 1, characterized in that, Before the step of determining the first pseudorange based on the ranging result, the method further includes: The integer part is determined based on the optimal sampling point and the correlation value of two adjacent points; The fractional part is calculated based on the optimal sampling point and the correlation values ​​of two adjacent points.

4. The master-slave station synchronization tracking method according to claim 3, characterized in that, The expression for calculating the difference between the first measurement pseudorange and the second measurement pseudorange is as follows: ， Where i represents the round number corresponding to the measurement of pseudorange. The difference is the stated value.

5. The master-slave station synchronization tracking method according to claim 4, characterized in that, When the actual distance between the master and slave stations remains unchanged, the step of synchronizing and tracking the frequency control word and initial phase of the master station clock based on the difference includes: When the difference in the measured pseudorange is not equal to zero, the step size of the frequency control word is adjusted based on the first adjustment step coefficient; wherein, the adjustment formula of the frequency control word is: ， The FCW is the frequency control word. To adjust the step size; When the difference is adjusted to a preset threshold range, the step size of the frequency control word is adjusted based on the second adjustment step coefficient, and the initial phase value is adjusted according to the ranging value of the fractional part; wherein, the adjustment formula for the initial phase value is: ， The PHS is the initial phase value. The adjustment step for the initial phase value.

6. The master-slave station synchronization tracking method according to claim 5, characterized in that, After the steps of adjusting the step size of the frequency control word based on the second adjustment step coefficient and adjusting the initial phase value according to the ranging value of the fractional part, the method further includes: Acquire the ranging value during tracking; If the ranging value fluctuates within the preset fluctuation range, then it is determined that the synchronization tracking of the frequency control word and initial phase of the master station clock is completed.

7. A master-slave station synchronization tracking device, characterized in that, include: The acquisition module is used to acquire the ranging results sent by the main station; The determining module is used to determine a first measurement pseudorange based on the ranging result; The calculation module is used to calculate the difference between the first measurement pseudorange and the second measurement pseudorange; wherein the second measurement pseudorange is the measurement pseudorange determined by the previous ranging result; The ranging result includes the integer part and the fractional part of the sampling period. The expression for determining the first measurement pseudorange based on the ranging result is: ， Among them, T F For the measured pseudorange, T s The sampling period is τ, and the fractional part is τ. The tracking module is used to synchronize and track the frequency control word and initial phase of the master station clock based on the difference.

8. An electronic device, characterized in that, Includes memory and processor, of which: The processor is used to execute computer programs stored in the memory; When the processor executes the computer program, it implements the steps in the master-slave station synchronization tracking method according to any one of claims 1 to 6.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by the processor, it implements the steps of the master-slave station synchronization tracking method according to any one of claims 1 to 6.

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