Satellite positioning signal generation method based on Doppler effect simulation

Abstract

The invention discloses a satellite positioning signal generation method based on Doppler effect simulation, and relates to the technical field of satellite positioning, and the method comprises the steps: obtaining a first position coordinate and a second position coordinate of a satellite at an initial moment and within one second adjacent to the initial moment, and calculating a first theoretical pseudo-range and a second theoretical pseudo-range through combining with a prepared user coordinate; a reference parameter of the hardware equipment is initialized by using a difference value between the first theoretical pseudo-range and the second theoretical pseudo-range, then the frequency control word is updated based on a pseudo-range difference value in two adjacent seconds every second so as to update the reference parameter, finally the hardware equipment executes parameter updating, and the actual pseudo-range is calibrated and compensated through double counters. By accurately controlling the Doppler effect of the chip, the positioning effect of an area which cannot be covered by a satellite signal can be effectively improved, and compared with the prior art, the Doppler effect is more accurately reproduced when the satellite signal is simulated, so that the positioning accuracy is improved.

Description

Technical Field

[0001] This invention relates to the field of satellite positioning technology, and in particular to a method for generating satellite positioning signals based on Doppler effect simulation. Background Technology

[0002] In existing satellite positioning systems, signal coverage has certain limitations. In certain areas, such as urban canyons, tunnels, and underground facilities, satellite signals may not reach user equipment directly, leading to positioning difficulties or reduced accuracy. Although some traditional signal enhancement and simulation techniques exist, they are insufficient in simulating the Doppler effect of satellite signals. This is because the Doppler effect is caused by the high-speed motion of the satellite, and accurately simulating this effect requires comprehensive consideration of various complex factors such as the satellite's trajectory, speed, and signal propagation time. Furthermore, high-precision signal control and synchronization are needed at both the hardware and software levels.

[0003] Existing technologies cannot accurately simulate the Doppler effect of satellite signals or precisely reproduce the actual motion characteristics of satellite signals. This results in differences between the analog signals received by user equipment and the real satellite signals in areas not covered by satellite signals, thus affecting positioning accuracy. Summary of the Invention

[0004] In view of this, this application provides a satellite positioning signal generation method based on Doppler effect simulation to address the shortcomings of existing technologies.

[0005] The first aspect of this application provides a method for generating satellite positioning signals based on Doppler effect simulation, comprising: At that time, the beacon module receives the real-time message data from the satellite, parses it, obtains the corresponding satellite's position coordinates, and records them as the first position coordinates; Determine the user coordinates, and based on the user coordinates and the first position coordinates, calculate the theoretical pseudorange between the user and the satellite, denoted as the first theoretical pseudorange; At that time, the beacon module receives the real-time message data from the satellite, parses it, and obtains the corresponding satellite's position coordinates, which are recorded as the second position coordinates; Based on the user coordinates and the second location coordinates, the theoretical pseudorange between the user and the satellite is calculated and denoted as the second theoretical pseudorange. Based on the difference between the first theoretical pseudorange and the second theoretical pseudorange, reference parameters are provided for the hardware device for initialization, including the simulated satellite signal propagation delay time, the simulated satellite signal initialization phase, and the frequency control word. The frequency control word is used to control the code rate and carrier frequency of the simulated satellite signal in the next second. Based on the difference in theoretical pseudorange between the user and the satellite within two adjacent seconds, the frequency control word for the next second is calculated every second, and the reference parameters are updated accordingly. The hardware device executes the corresponding frequency control word based on updated reference parameters and uses dual counters to calibrate and compensate for the actual pseudorange between the user and the satellite.

[0006] In one possible implementation of the first aspect, obtaining the simulated satellite signal propagation delay time includes: The number of clock cycles for the hardware device. For the first theoretical pseudorange, The operating clock frequency of the hardware device. The speed of light; To round up the number of clock cycles for the hardware device; To simulate the satellite signal propagation delay time.

[0007] In one possible implementation of the first aspect, obtaining the initial phase of the simulated satellite signal includes: This indicates that the clock cycle count of the hardware device is rounded up. To compensate for the fractional period deviation in the number of clock cycles of the hardware device; The fractional periodic deviation is converted into a code phase count value, and the code phase count value is used as the initial phase of the analog satellite signal.

[0008] In one possible implementation of the first aspect, the frequency control word includes a frequency control word for the code rate and a frequency control word for the carrier frequency.

[0009] In one possible implementation of the first aspect, the frequency control word for obtaining the code rate includes: The current bit rate of the analog satellite signal. To adjust the bit rate for simulating satellite signals in the next second, For the first theoretical pseudorange, For the second theoretical pseudorange, The speed of light; The adjusted bitrate is converted into a frequency control word with the corresponding bitrate.

[0010] In one possible implementation of the first aspect, the frequency control word for obtaining the carrier frequency includes: To simulate the current carrier frequency of the satellite signal, Adjusting the carrier frequency to simulate satellite signals for the next second; The adjusted carrier frequency is converted into a frequency control word for the corresponding carrier frequency.

[0011] One possible implementation of the first aspect also includes: Once initialization is complete, the reference parameters and PPS second pulses are sent to the hardware device. The hardware device receives the PPS second pulse and starts the hardware device at the initialization time of the PPS second pulse; Once the benchmark parameters are updated, the updated benchmark parameters are sent to the hardware device. The hardware device receives updated reference parameters and executes the updated reference parameters at the rising edge of the PPS second pulse.

[0012] In one possible implementation of the first aspect, the hardware device executing the corresponding frequency control word based on updated reference parameters further includes: Obtain the frequency control word for the code rate in the corresponding frequency control word, and convert it into an adjusted code rate through hardware counting logic; Based on the adjusted code rate, the generation frequency of the actual code chip is controlled.

[0013] In one possible implementation of the first aspect, the hardware device executing the corresponding frequency control word based on updated reference parameters includes: Obtain the frequency control word of the carrier frequency in the corresponding frequency control word, and convert it into an adjustment of the carrier frequency through hardware counting logic; Based on the aforementioned adjustment of the carrier frequency, the actual carrier frequency is controlled.

[0014] In one possible implementation of the first aspect, the use of dual counters to calibrate and compensate for the actual pseudorange between the user and the satellite includes: A chip counter and a second counter are used to establish the correlation between chips and time, and the correlation result is obtained; use The signal is synchronized with the real satellite time to obtain the synchronization result; Based on the synchronization results and the correlation results, the frequency control word of the code rate is adjusted to ensure that the actual pseudorange matches the corresponding theoretical pseudorange.

[0015] Its beneficial effects are as follows: This invention discloses a satellite positioning signal generation method based on Doppler effect simulation. By acquiring the first and second position coordinates of the satellite at the initial moment and within the adjacent second, and combining this with the planned user coordinates, a first and second theoretical pseudorange are calculated. The difference between the first and second theoretical pseudoranges is used to initialize the reference parameters of the hardware device. Then, every second, the frequency control word is updated based on the pseudorange difference between two adjacent seconds to update the reference parameters. Finally, the hardware device executes the parameter update and compensates for the actual pseudorange through dual counter calibration. This invention, by precisely controlling the Doppler effect of the code chip, can effectively improve the positioning effect in areas where satellite signals cannot reach. Compared with existing technologies, this invention more accurately reproduces the Doppler effect when simulating satellite signals, thereby improving positioning accuracy. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of this application. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0017] Figure 1 This is a schematic flowchart of a satellite positioning signal generation method based on Doppler effect simulation provided in an embodiment of this application; Figure 2 This is a schematic diagram of the composition of the beacon system in an embodiment of this application. Detailed Implementation

[0018] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. 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.

[0019] In this application, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes the element.

[0020] Example In existing technologies, it is impossible to accurately simulate the Doppler effect of satellite signals and precisely reproduce the actual motion characteristics of satellite signals. This results in differences between the analog signals received by user equipment and the real satellite signals in areas not covered by satellite signals, thus affecting positioning accuracy.

[0021] Therefore, this application provides a satellite positioning signal generation method based on Doppler effect simulation, such as... Figure 1 As shown, it includes: At that time, the beacon module receives the real-time message data from the satellite, parses it, obtains the corresponding satellite's position coordinates, and records them as the first position coordinates; Determine the user coordinates, and based on the user coordinates and the first position coordinates, calculate the theoretical pseudorange between the user and the satellite, denoted as the first theoretical pseudorange; At that time, the beacon module receives the real-time message data from the satellite, parses it, and obtains the corresponding satellite's position coordinates, which are recorded as the second position coordinates; Based on the user coordinates and the second location coordinates, the theoretical pseudorange between the user and the satellite is calculated and denoted as the second theoretical pseudorange. Based on the difference between the first theoretical pseudorange and the second theoretical pseudorange, reference parameters are provided for the hardware device for initialization, including the simulated satellite signal propagation delay time, the simulated satellite signal initialization phase, and the frequency control word. The frequency control word is used to control the code rate and carrier frequency of the simulated satellite signal in the next second. Based on the difference in theoretical pseudorange between the user and the satellite within two adjacent seconds, the frequency control word for the next second is calculated every second, and the reference parameters are updated accordingly. The hardware device executes the corresponding frequency control word based on updated reference parameters and uses dual counters to calibrate and compensate for the actual pseudorange between the user and the satellite.

[0022] To better illustrate the principles of this application, a brief introduction to existing beacon systems is first given, such as... Figure 2 The diagram shows the composition of a beacon system. The main body of the beacon system includes a central module and multiple beacon modules. The central module first receives satellite navigation data, positioning, and clock discipline. Then, it transmits the real-time message data and PPS synchronization signals from the satellites participating in the positioning process to the subsequent beacon modules via optical fiber. There may be 5 to 10 beacon modules, theoretically an unlimited number. Each beacon module is provided with virtual positioning coordinates (generally set to the actual coordinates of the beacon's location). The beacon modules calculate the real-time position coordinates of the satellites (ECEF coordinate system) using the real-time message data provided by the central module, and then simulate and transmit real-time satellite signals through relevant calculations to complete the assisted positioning.

[0023] The embodiments of this application illustrate the working principle based on a timeline, focusing on software computation, hardware logic, and their coordination, including: The software calculation is divided into an initialization phase and an update phase. The core logic is based on the relative motion between the satellite and the user target, converting physical quantities (pseudorange, Doppler offset) into hardware-executable control parameters to ensure the realism of the simulated satellite signal. Specifically: I. Initialization Phase ( and Initialization provides initial reference parameters for the hardware devices. The core purpose of initialization is to determine the signal reference when the beacon system starts up, including the simulated satellite signal propagation delay time, initial phase and frequency control word, to ensure that the hardware devices conform to the propagation law of real satellite signals from the moment of startup.

[0024] Step 1: Calculation The first theoretical pseudorange of time and The second theoretical pseudo-distance at time Pseudorange is the straight-line distance between the satellite's position coordinates and the user's coordinates as defined by the beacon system. It represents the propagation path length of the actual satellite signal from its transmission to the user's coordinates. In this embodiment, the relative motion between the satellite and the user is captured by the pseudorange difference between adjacent 1-second intervals. Because the distance between the satellite and the user changes over time due to the satellite's orbital motion, this difference is the core basis for subsequent calculation of Doppler offset (relative motion produces Doppler offset, which is reflected in pseudorange changes).

[0025] Step 2: Calculate the signal propagation delay The above formula first converts the theoretical pseudorange into the corresponding number of hardware clock cycles. Then the number of hardware clock cycles is rounded up. (The hardware can only process integer counts; rounding can reduce truncation errors.) The final delay time count is... This represents the number of hardware clock cycles required for a satellite signal to travel from transmission to reception, providing a time reference for signal propagation in the hardware.

[0026] Step 3: Calculate the initial phase Due to calculation The number of clock cycles for the delay time may include a fractional part (e.g., 100.3 clock cycles), which can cause a deviation in the initial phase of the signal. If not compensated, subsequent rate control will accumulate errors, affecting positioning accuracy.

[0027] The fractional part of the delay time is calculated using the above formula and rounded up, which is the fractional period deviation.

[0028] Then, the fractional period deviation is converted into a code phase count value using the following formula: in, It converts the bit rate unit from MHz to Hz. It is the spatial length of the chip. It converts the fractional part of the delay time into chip phase offset, because the hardware device uses Bit-precision counting requires amplification of the phase offset. This is multiplied and converted into a hardware-recognizable phase count value; After rounding to the nearest integer to eliminate decimal errors, the initial phase is finally obtained. When the hardware starts up, the code phase counter starts counting from the initial phase instead of 0, in order to compensate for the phase deviation caused by the fractional part of the delay time and ensure that the starting phase of the signal is accurate.

[0029] Step 4: Calculate the frequency control word The Doppler shift is translated into a hardware-executable frequency control word. The Doppler effect causes the frequency of satellite signals to shift (the frequency increases when the satellite is close and decreases when it is far away). This effect needs to be reproduced by adjusting the code rate and carrier frequency.

[0030] It is the radial velocity of the satellite relative to the user. It is the Doppler offset of the bit rate. The real-time bitrate (adjusted bitrate) includes Doppler shift. Similarly, given the original carrier frequency, the real-time carrier frequency including the Doppler shift can be obtained. ; After calculating the adjusted code rate and carrier frequency, they need to be converted into frequency control words that can be recognized by hardware devices. The specific conversion uses the following formula. Taking the B1C signal as an example, the original carrier frequency is 1575.42MHz: The essence of a frequency control word is the ratio of the target frequency to the hardware clock frequency. When the counter is full At that time, it corresponds exactly to one cycle of the target bit rate; This involves rounding the frequency control word to the nearest integer to obtain an integer control word that the hardware can recognize. The computational logic and Consistent.

[0031] Step 5: Send parameters and initialization pulse (PPS second pulse) After initialization is complete, the signal propagation delay time is... Initialize phase Frequency control word for bit rate Frequency control word for carrier frequency Configure the hardware parameters for the hardware device; A PPS second pulse signal is sent to the hardware device as a trigger signal for hardware startup. After receiving the pulse, the hardware device immediately loads the above parameters and begins to simulate satellite signals, ensuring that the hardware device works according to the configuration parameters from the moment of startup.

[0032] II. Update Phase ( and (Time), dynamically adapting to real-time satellite motion As satellites continuously move in their orbits, the intensity of the Doppler effect changes over time. Therefore, parameters need to be updated every second to ensure that the simulated satellite signal always matches the satellite's real-time motion.

[0033] Step 1: Calculation Time pseudo-distance and calculation Time pseudo-distance Step 2: Calculate the signal propagation delay time Step 3: Calculate the new frequency control word The above calculation logic is the same as the initialization steps, and will not be elaborated further.

[0034] Step 4: Update hardware device parameters The frequency control word parameters are updated at the initialization time and at the rising edge of the PPS second pulse. The PPS second pulse signal provides a unified time reference to ensure that the hardware device parameter update is synchronized with the hardware execution time (avoiding misalignment between parameter update and hardware device working timing).

[0035] The core function of the hardware logic is to output simulated satellite signals that conform to the real Doppler effect, strictly according to the parameters generated by the software, and to eliminate timing errors through real-time calibration. This is divided into frequency control word execution and pseudorange information calibration, including: Execution frequency control word: The code rate control word and carrier frequency control word generated by the software calculation need to be converted into the actual code rate and carrier frequency through hardware counting logic.

[0036] The hardware device has a built-in code phase counter, with an initial value of Then, a new load is applied every second at the rising edge of the PPS second pulse. The code phase counter increments by 1 each time according to the hardware clock frequency, until the count value reaches 1. When the time comes, it will automatically reset to zero.

[0037] At the start of the chip, the falling edge of the 48th bit of the code phase counter is used to determine the starting point of the chip. When the bit changes to 0, the 48th bit changes from 1 to 0, generating a falling edge. This moment coincides with the code phase counter reaching full count. The moment corresponds to the start of a bitrate cycle, ensuring that the chip generation frequency strictly matches the adjusted bitrate calculated by the software.

[0038] This embodiment also sets... Signal, The signal goes high at the moment each chip is transmitted. The hardware device uses this signal to synchronize the generation and output of chips, ensuring that the user can correctly receive and parse the chip sequence.

[0039] The hardware device has a built-in carrier waveform table that stores one cycle of... and Waveform data (64 sampling points in total, corresponding to one period of the carrier wave). The 64 sampling points can cover the complete period of the sine wave, ensuring the continuity of the carrier waveform.

[0040] The first 6 bits of the carrier frequency control word are used as the waveform table address. The 6 bits can represent 64 addresses from 0 to 63, which correspond exactly to the 64 sampling points of the waveform table. The speed at which the first 6 bits change, incrementing with the hardware clock, determines the speed at which the waveform table is read, and thus the carrier frequency. When the carrier frequency control word is updated, the speed at which the first 6 bits change, and the carrier frequency shifts accordingly, accurately reproducing the Doppler effect caused by satellite motion.

[0041] The satellite's orbital speed is relatively stable, so the Doppler shift changes little per second. There is no need for higher frequency parameter updates. The frequency control word can be updated once per second via the PPS pulse signal to meet the simulation accuracy requirements, while reducing the complexity of software and hardware coordination.

[0042] Pseudorange information calibration: The software calculates the theoretical pseudorange corresponding to the delay time updated per second, but in actual operation, the actual pseudorange may not match the theoretical pseudorange due to counting errors (such as clock drift and parameter loading delay). This deviation needs to be compensated through calibration.

[0043] Ensure that the time from the rising edge of the PPS second pulse to the start position of the current chip is perfectly matched with the pseudorange calculated by the software. The propagation time corresponding to the pseudorange is the time from the satellite signal being transmitted to the user, while the rising edge of the PPS second pulse is a unified time reference. Matching the two can avoid the cumulative timing error from affecting the positioning accuracy.

[0044] This embodiment uses dual counters to calibrate and compensate for the actual pseudorange. Taking a B1C signal as an example (code rate 1.023MHz, i.e., 1,023,000 chips per second, 1,023 chips per millisecond), the hardware establishes a correlation between chip count and time through two counters to obtain the correlation result, including: Chip counter :whenever The signal is pulled high once (generating 1 chip). Add 1, when When the count reaches 1022 (1023-1), it means that 1 millisecond of timing has been completed; Second counter :when Count to 1022 and When the price is pulled up (timeout completes in 1 millisecond). Add 1; when When the count reaches 999 (1000-1), it means that 1 second has elapsed. when , and When the signal goes high, the hardware generates This signal corresponds to the start time of a 1-second cycle of a real satellite and is used to synchronize with real satellite time; all parameters sent by the software are in... Constantly synchronized with the hardware clock to ensure consistent time base between software and hardware (software calculates parameters according to real satellite time, hardware calculates according to...). Parameters to be executed at all times. The signal is synchronized with real satellite time, thus avoiding timing misalignment.

[0045] At the rising edge of the PPS second pulse, the hardware adjusts the frequency control word to calibrate and compensate for the actual pseudorange between the user and the satellite, ensuring that the actual pseudorange matches the corresponding theoretical pseudorange. Specifically, this is done by calculating the number of untransmitted chips to adjust the frequency control word, including: Calculate the remaining time parameter. The number of milliseconds remaining in the current second. The number of milliseconds that have been completed (e.g.) (This indicates that 500 milliseconds have elapsed, with 499 milliseconds remaining). The number of chip fragments remaining in the current millisecond. It is the number of completed chips (e.g.) This means that 500 chips have passed in the current millisecond, and 522 chips remain. The remaining count value of the current code phase counter. This is the current count value, and the remaining count value. The number of counts required until the next overflow is used for fine-tuning the code phase; The total number of untransmitted chips in the current second, where 1 millisecond contains 1023 chips, and the number of chips corresponding to the remaining milliseconds is... Add the number of remaining code chips in the current milliseconds. This gives the total number of remaining chips, representing the number of chips that still need to be sent from the current PPS time to the current chip start position.

[0046] Adjusting the frequency control word, the theoretical number of chips corresponding to the pseudorange = pseudorange x code rate / C, while the actual number of remaining chips is... It is necessary to adjust the frequency control word of the code rate to make Match with the theoretical number of chips; The bitrate adjustment factor is obtained by quoting the delay time sent by the software, and then multiplied by... (Precision magnification) yields a new code rate frequency control word. This adjustment ensures that the actual time from the PPS second pulse moment to the chip start position is completely consistent with the propagation time corresponding to the theoretical pseudorange, eliminating timing deviations caused by hardware counting errors.

[0047] In this embodiment, the software calculates the pseudorange difference based on the satellite's real-time position every second, converts it into a delay time and a frequency control word, and sends it to the hardware device via the PPS second pulse. The hardware device loads new parameters at the rising edge of the PPS second pulse and performs frequency control via the frequency control word, generating a chip and carrier signal conforming to the Doppler effect. Simultaneously, it uses dual counters and... Signal calibration timing ensures that the actual pseudorange matches the theoretical pseudorange. Through hardware and software collaboration, a positioning signal with Doppler effect, consistent with real satellite signals, is simulated in areas not covered by satellite signals (such as tunnels and urban canyons), providing high-precision positioning support for user equipment.

[0048] In some embodiments, obtaining the simulated satellite signal propagation delay time includes: The number of clock cycles for the hardware device. For the first theoretical pseudorange, The operating clock frequency of the hardware device. The speed of light; To round up the number of clock cycles for the hardware device; To simulate the satellite signal propagation delay time.

[0049] In some embodiments, obtaining the initial phase of the simulated satellite signal includes: This indicates that the clock cycle count of the hardware device is rounded up. To compensate for the fractional period deviation in the number of clock cycles of the hardware device; The fractional periodic deviation is converted into a code phase count value, and the code phase count value is used as the initial phase of the analog satellite signal.

[0050] In some embodiments, the frequency control word includes a code rate frequency control word and a carrier frequency frequency control word.

[0051] In some embodiments, the frequency control word for obtaining the code rate includes: The current bit rate of the analog satellite signal. To adjust the bit rate for simulating satellite signals in the next second, For the first theoretical pseudorange, For the second theoretical pseudorange, The speed of light; The adjusted bitrate is converted into a frequency control word with the corresponding bitrate.

[0052] In some embodiments, the frequency control word for obtaining the carrier frequency includes: To simulate the current carrier frequency of the satellite signal, Adjusting the carrier frequency to simulate satellite signals for the next second; The adjusted carrier frequency is converted into a frequency control word for the corresponding carrier frequency.

[0053] In some embodiments, it also includes: Once initialization is complete, the reference parameters and PPS second pulses are sent to the hardware device. The hardware device receives the PPS second pulse and starts the hardware device at the initialization time of the PPS second pulse; Once the benchmark parameters are updated, the updated benchmark parameters are sent to the hardware device. The hardware device receives updated reference parameters and executes the updated reference parameters at the rising edge of the PPS second pulse.

[0054] In some embodiments, the hardware device executing the corresponding frequency control word based on updated reference parameters further includes: Obtain the frequency control word for the code rate in the corresponding frequency control word, and convert it into an adjusted code rate through hardware counting logic; Based on the adjusted code rate, the generation frequency of the actual code chip is controlled.

[0055] In some embodiments, the hardware device executes a corresponding frequency control word based on updated reference parameters, including: Obtain the frequency control word of the carrier frequency in the corresponding frequency control word, and convert it into an adjustment of the carrier frequency through hardware counting logic; Based on the aforementioned adjustment of the carrier frequency, the actual carrier frequency is controlled.

[0056] In some embodiments, using dual counters to calibrate and compensate for the actual pseudorange between the user and the satellite includes: A chip counter and a second counter are used to establish the correlation between chips and time, and the correlation result is obtained; use The signal is synchronized with the real satellite time to obtain the synchronization result; Based on the synchronization results and the correlation results, the frequency control word of the code rate is adjusted to ensure that the actual pseudorange matches the corresponding theoretical pseudorange.

[0057] Those skilled in the art will further recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, computing software, or a combination of both. To clearly illustrate the interchangeability of hardware and software, the components and steps of the various examples have been generally described in terms of functionality in the foregoing description. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0058] Although preferred embodiments of the invention have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including both the preferred embodiments and all changes and modifications falling within the scope of the invention.

[0059] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this invention and their equivalents, this invention also intends to include these modifications and variations.

Claims

1. A method for generating satellite positioning signals based on Doppler effect simulation, wherein the beacon system comprises a central module and multiple beacon modules, characterized in that, include: At that time, the beacon module receives the real-time message data from the satellite, parses it, obtains the corresponding satellite's position coordinates, and records them as the first position coordinates; Determine the user coordinates, and based on the user coordinates and the first position coordinates, calculate the theoretical pseudorange between the user and the satellite, denoted as the first theoretical pseudorange; At that time, the beacon module receives the real-time message data from the satellite, parses it, and obtains the corresponding satellite's position coordinates, which are recorded as the second position coordinates; Based on the user coordinates and the second location coordinates, the theoretical pseudorange between the user and the satellite is calculated and denoted as the second theoretical pseudorange. Based on the difference between the first theoretical pseudorange and the second theoretical pseudorange, reference parameters are provided for the hardware device for initialization, including the simulated satellite signal propagation delay time, the simulated satellite signal initialization phase, and the frequency control word. The frequency control word is used to control the code rate and carrier frequency of the simulated satellite signal in the next second. Based on the difference in theoretical pseudorange between the user and the satellite within two adjacent seconds, the frequency control word for the next second is calculated every second, and the reference parameters are updated accordingly. The hardware device executes the corresponding frequency control word based on updated reference parameters and uses dual counters to calibrate and compensate for the actual pseudorange between the user and the satellite.

2. The satellite positioning signal generation method based on Doppler effect simulation according to claim 1, characterized in that, Obtaining the simulated satellite signal propagation delay time includes: The number of clock cycles for the hardware device. For the first theoretical pseudorange, The operating clock frequency of the hardware device. The speed of light; To round up the number of clock cycles for the hardware device; To simulate the satellite signal propagation delay time.

3. The satellite positioning signal generation method based on Doppler effect simulation according to claim 2, characterized in that, Obtaining the initial phase of the simulated satellite signal includes: This indicates that the clock cycle count of the hardware device is rounded up. To compensate for the fractional period deviation in the number of clock cycles of the hardware device; The fractional periodic deviation is converted into a code phase count value, and the code phase count value is used as the initial phase of the analog satellite signal.

4. The satellite positioning signal generation method based on Doppler effect simulation according to claim 1, characterized in that, The frequency control word includes a frequency control word for the code rate and a frequency control word for the carrier frequency.

5. The satellite positioning signal generation method based on Doppler effect simulation according to claim 4, characterized in that, The frequency control words for obtaining the code rate include: The current bit rate of the analog satellite signal. To adjust the bit rate for simulating satellite signals in the next second, For the first theoretical pseudorange, For the second theoretical pseudorange, The speed of light; The adjusted bitrate is converted into a frequency control word with the corresponding bitrate.

6. The satellite positioning signal generation method based on Doppler effect simulation according to claim 5, characterized in that, The frequency control word for obtaining the carrier frequency includes: To simulate the current carrier frequency of the satellite signal, Adjusting the carrier frequency to simulate satellite signals for the next second; The adjusted carrier frequency is converted into a frequency control word for the corresponding carrier frequency.

7. The satellite positioning signal generation method based on Doppler effect simulation according to claim 1, characterized in that, Also includes: Once initialization is complete, the reference parameters and PPS second pulses are sent to the hardware device. The hardware device receives the PPS second pulse and starts the hardware device at the initialization time of the PPS second pulse; Once the benchmark parameters are updated, the updated benchmark parameters are sent to the hardware device. The hardware device receives updated reference parameters and executes the updated reference parameters at the rising edge of the PPS second pulse.

8. The satellite positioning signal generation method based on Doppler effect simulation according to claim 5, characterized in that, The hardware device, based on updated reference parameters, further includes executing the corresponding frequency control word: Obtain the frequency control word for the code rate in the corresponding frequency control word, and convert it into an adjusted code rate through hardware counting logic; Based on the adjusted code rate, the generation frequency of the actual code chip is controlled.

9. The satellite positioning signal generation method based on Doppler effect simulation according to claim 6, characterized in that, The hardware device executes the corresponding frequency control word based on updated reference parameters, including: Obtain the frequency control word of the carrier frequency in the corresponding frequency control word, and convert it into an adjustment of the carrier frequency through hardware counting logic; Based on the aforementioned adjustment of the carrier frequency, the actual carrier frequency is controlled.

10. The satellite positioning signal generation method based on Doppler effect simulation according to claim 1, characterized in that, The calibration and compensation of the actual pseudorange between the user and the satellite using dual counters includes: A chip counter and a second counter are used to establish the correlation between chips and time, and the correlation result is obtained; use The signal is synchronized with the real satellite time to obtain the synchronization result; Based on the synchronization results and the correlation results, the frequency control word of the code rate is adjusted to ensure that the actual pseudorange matches the corresponding theoretical pseudorange.

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