Voltage-controlled crystal oscillator frequency adjusting method based on public network signal scanning

Abstract

The invention discloses a voltage-controlled crystal oscillator frequency adjustment method based on public network signal scanning, which comprises the steps of signal scanning, signal capturing, voltage-controlled voltage generation, voltage-controlled voltage adjustment, closed-loop feedback and stability enhancement and frequency protection, and is characterized in that a VCXO can ensure the synchronism and correctness among all parts and reduce the problems of time deviation and jitter. According to the voltage-controlled crystal oscillator frequency adjustment method based on public network signal scanning, the high consistency between a local clock and a base station clock is ensured, so that the problems of signal demodulation errors, low sampling efficiency and the like caused by clock frequency offset are effectively avoided, autonomous synchronization without a GPS module is successfully realized through circuit design and algorithm optimization, and the method is suitable for large-scale popularization and application. The hardware cost of the equipment is greatly reduced, and the power consumption is effectively controlled while high-precision synchronization of the equipment is kept through an efficient synchronization algorithm and a low-power-consumption circuit design. Therefore, the endurance time of the equipment is prolonged, and the overall energy efficiency of the equipment is improved.

Description

Technical Field

[0001] The invention relates to the field of voltage-controlled crystal oscillator frequency adjustment, and in particular to a voltage-controlled crystal oscillator frequency adjustment method based on public network signal scanning. Background Art

[0002] In the field of public network signal acquisition, the stability and accuracy of equipment performance are crucial. However, a technical problem that has long plagued this field is that public network signal acquisition equipment often has a frequency offset (frequency deviation) between its local clock and the base station clock, which causes errors in the signal demodulation process or greatly reduces the sampling efficiency. This frequency deviation problem not only affects the accuracy of data acquisition, but also seriously restricts the overall performance and application scope of the signal acquisition equipment; To meet this challenge, the industry has traditionally adopted a variety of solutions. One of the solutions is to rely on external GPS signals to synchronize local clocks. Although GPS signals can provide relatively accurate clock synchronization in an open environment, they are often not effectively received in indoor environments or when there are obstructions, resulting in clock synchronization failure. In addition, the introduction of GPS modules also increases the hardware cost of the device, which is undoubtedly a considerable burden for cost-sensitive application scenarios, and the use of phase-locked loop (PLL) circuits for clock synchronization. The PLL circuit attempts to lock the local clock to the frequency of the base station clock through a complex filtering design. However, this solution also has many shortcomings. First, the design of the PLL circuit is relatively complex and requires precise filtering parameter settings to ensure the stability of clock synchronization. Second, the response speed of the PLL circuit is relatively slow. When the base station clock frequency changes, the PLL circuit takes a long time to re-lock, which is difficult to meet the application requirements of fast switching of multiple frequency bands.

[0003] Therefore, traditional solutions have certain limitations and shortcomings when dealing with clock synchronization issues of public network signal acquisition equipment. Summary of the invention

[0004] In view of the deficiencies in the prior art, the present application provides a voltage-controlled crystal oscillator frequency adjustment method based on public network signal scanning to solve the above-mentioned technical problems of slow response speed and difficulty in adapting to fast switching of multiple frequency bands.

[0005] To achieve the above purpose, the present application provides the following technical solution: a voltage-controlled crystal oscillator frequency adjustment method based on public network signal scanning, comprising: S1: Signal Scan The public network frequency band is scanned by using a scanning system. The RF front-end component has sufficient bandwidth to cover all or part of the public network frequency band, so that wireless signals from different frequency points can be received. During the scanning process, the received wireless signal is pre-processed, including filtering, amplification and analog-to-digital conversion, to extract effective signal components that may contain the synchronization signal of the target base station, and the pre-processed signal is analyzed to identify and capture the synchronization signal of the target base station.

[0006] S2: Signal Capture After successfully capturing the synchronization signal, the peak value is calculated, which reflects the degree of match between the synchronization signal and the locally generated reference signal. It is used to evaluate the strength and reliability of the signal. The relevant peak value of the synchronization signal and its position information in the time domain and / or frequency domain are recorded and output, including the specific time point when the synchronization signal appears, the frequency offset, and the relative position relative to the scanning starting point, thereby providing detailed information about the status of the target base station.

[0007] S3: Voltage Controlled Voltage Generation The carrier frequency deviation is extracted from the processed digital baseband signal, and the carrier frequency deviation represents the difference between the received signal carrier frequency and the reference carrier frequency generated by the local oscillator. It extracts the continuous monitoring and analysis of the signal phase change, calculates the frequency error of the local crystal oscillator, converts the deviation value into the error percentage or absolute frequency deviation value relative to the nominal frequency of the local crystal oscillator, and outputs the frequency error information of the local crystal oscillator for subsequent calibration, compensation and recording.

[0008] S4: Voltage Control Voltage Adjustment The information value obtained in step S3 is input into the PID controller to generate a voltage-controlled voltage adjustment value, and the value is loaded into the voltage-controlled end of the VCXO module through the DAC module to adjust the output frequency.

[0009] S5: Closed-loop feedback and enhanced stability Monitor the frequency convergence status after adjustment in real time. If it exceeds the threshold, trigger the resynchronization process. When the signal is lost, enable the hold mode to keep the historical data stable for a short time.

[0010] S6: Frequency protection Turn on the electromagnetic field shielding equipment to protect the frequency.

[0011] Preferably, in step S1, the synchronization signal includes a primary synchronization signal, a secondary synchronization signal, and a signal mode for base station identification and time synchronization. The primary synchronization signal is also used to achieve coarse time synchronization between the UE and the base station, laying the foundation for subsequent fine synchronization and channel estimation processes. The secondary synchronization signal is used in conjunction with the primary synchronization signal to achieve precise synchronization between the UE and the base station. After capturing the primary synchronization signal, the UE will further search for the secondary synchronization signal to improve signal accuracy, help the UE accurately identify the base station, and achieve precise time synchronization with the base station.

[0012] Preferably, in step S3, the information is represented in digital form, including timestamp, deviation type and specific error value. The digitally represented frequency information can achieve higher accuracy and stability. The development of digital signal processing technology makes it possible to accurately control the frequency. The frequency can be fine-tuned through digital algorithms to achieve extremely high accuracy requirements. In communication, measurement and control systems, high-precision frequency sources are essential to ensure signal synchronization and improve the reliability and accuracy of data transmission. The voltage-controlled crystal oscillator can stably output a frequency signal that meets the requirements through digital control, so that the voltage-controlled crystal oscillator can easily communicate with other digital devices to achieve automatic control. The digitally controlled voltage-controlled crystal oscillator can be easily integrated into various digital systems to improve the overall performance and reliability of the system.

[0013] Preferably, in step S6, the electromagnetic field shielding device includes a metal shielding cover, which is arranged outside the crystal oscillator. The metal shielding cover can ensure the accuracy of the crystal oscillator output frequency, thereby ensuring the correct execution of the system's timing logic, reducing data transmission errors or losses caused by unstable crystal oscillator frequency, and improving the communication performance of the system.

[0014] Preferably, in step S4: the PID controller is used to maintain the state stability of the controlled object and improve the control accuracy of the system, realize the automatic control and response speed of complex process parameters, and adjust the output of the controller according to the size of the current error. When the error is large, the output signal is also large, thereby speeding up the response speed of the controlled object. Proportional control can make the system quickly approach the set value, and adjust the output of the controller according to the amount of error accumulated over time. Eliminate the steady-state error of the system to ensure that the system eventually stabilizes near the set value. The role of integral control is similar to accumulating errors and continuously adjusting the output, and adjusting the output of the controller according to the rate of error change. Predict the future state change trend of the system, thereby reducing overshoot and improving the stability of the system. The introduction of differential control can suppress the oscillation of the system and make adjustments according to the input and output data of the system, so it has strong adaptability and flexibility.

[0015] Preferably, in step S4: the DAC module is a digital-to-analog converter, which is used to process the input digital signal, including filtering, amplification and digital signal processing algorithms. It is responsible for processing the input digital signal, such as filtering, amplification, and digital signal processing algorithms, converting the digital signal into an analog signal, and generating a corresponding analog voltage or current according to the input digital code. It is responsible for filtering, amplifying and other processing of the output analog signal to ensure the quality and stability of the signal.

[0016] Preferably, step S5: holding mode: the system uses previously collected data and model parameters to calculate the drift of the crystal oscillator output frequency, and performs self-correction compensation, uses the frequency drift model trained by historical data accumulated in the locked state to estimate the frequency output change trend, and uses the estimated value to compensate for the actual output frequency, thereby maintaining the frequency accuracy.

[0017] Preferably, step S5: voltage-controlled voltage adjustment includes a pre-adjustment circuit, and when the signal is lost, the capacitance component, the current near the crystal and the temperature compensation are adjusted according to the system settings, and the parameters of the device are automatically adjusted through the pre-adjustment circuit, thereby greatly improving the overall automation of the device.

[0018] Preferably, the scanning system includes a signal acquisition module, a synchronization error extraction module, a voltage-controlled voltage generation module, a VCXO module and a feedback control module, and the public network frequency band is scanned by the scanning system.

[0019] Preferably, the signal acquisition module is used for data acquisition function and signal conditioning and conversion, the synchronous error extraction module is used for error detection, error extraction and error correction, the voltage-controlled voltage generation module is used for voltage control, dynamic adjustment and improving system stability, the VCXO module is used to provide a stable frequency signal and frequency control, the feedback control module is used to maintain system stability, improve control accuracy, enhance system robustness, realize negative feedback and positive feedback and realize automatic correction, the signal acquisition module usually includes amplifiers, filters, analog-to-digital converters and other circuits for signal enhancement, filtering and digital processing, the signal acquisition module is mainly responsible for signal reception and transmission, ensuring the integrity and accuracy of the signal, and the synchronous error extraction module is used to generate a stable frequency signal and frequency control, and ..., and realizes negative feedback and positive feedback and automatic correction, the feedback control module is used to generate a stable frequency signal and frequency control, and the feedback control module is used to generate a stable frequency signal and frequency control, and the feedback control module is used to generate a stable frequency signal and frequency control, and the feedback control module is used to generate a The module can monitor the synchronization error between the received signal and the transmitted signal in real time. Through specific algorithms, such as the Gardner bit synchronization algorithm, the module can calculate the deviation between the received signal and the transmitted signal in time or phase. After detecting the synchronization error, the synchronization error extraction module can extract the error signal from the received signal. By adjusting the output frequency or phase of the digital control oscillator, the synchronization error between the received signal and the transmitted signal can be reduced, and the performance of the communication system can be improved. The voltage-controlled voltage generation module can achieve precise control of the output voltage. By adjusting the size of the control voltage, the value of the output voltage can be changed continuously and smoothly. It can quickly respond to changes in the external control voltage and realize dynamic adjustment of the output voltage. The core function of the VCXO module is to provide a stable frequency signal. It uses the high stability characteristics of the quartz crystal to generate a high-precision frequency signal. Through the control of the external voltage, the VCXO can fine-tune the output frequency within a certain range to meet the needs of different applications. By introducing the VCXO module, electronic equipment can achieve more precise frequency control and higher system performance.

[0020] VCXO can ensure the synchronization and correctness between various parts, reduce time deviation and jitter problems, and the feedback control module generates an error signal by comparing the system's output signal with the expected signal, and adjusts the input signal according to the error signal to stabilize the system near the expected output value. This mechanism can effectively cope with the parameter changes within the system and the interference of the external environment to ensure the stable operation of the system. By continuously measuring the output signal and comparing it with the expected signal, the feedback control module can adjust the input signal in real time, thereby reducing the output error of the system and improving the control accuracy. The feedback control module has strong robustness to the uncertainty of system parameters and external disturbances. The feedback control module can automatically adjust the control input according to the error signal so that the system output quickly approaches the expected value. In the control system, the feedback control module can realize two control modes: negative feedback and positive feedback. Negative feedback is used to stabilize the system output and reduce errors; while positive feedback is used to enhance the system output and improve the response speed of the system. The feedback control module selects the appropriate feedback mode in different application scenarios.

[0021] In summary, the present application provides a voltage-controlled crystal oscillator frequency adjustment method based on public network signal scanning, which has the following beneficial effects: 1. This voltage-controlled crystal oscillator frequency adjustment method based on public network signal scanning has extremely high synchronization accuracy and can accurately meet the strict requirements of air interface synchronization. In the field of public network signal acquisition and processing, the accuracy of air interface synchronization is a key factor in ensuring data transmission stability and improving communication efficiency. This solution ensures a high degree of consistency between the local clock and the base station clock through an innovative synchronization mechanism, thereby effectively avoiding problems such as signal demodulation errors and reduced sampling efficiency caused by clock offset; 2. This voltage-controlled crystal oscillator frequency adjustment method based on public network signal scanning achieves high-precision synchronization while completely eliminating the reliance on GPS modules. Traditional synchronization solutions often require the use of GPS signals to obtain accurate clock information, but this not only increases hardware costs, but also causes synchronization failures in indoor or blocked environments. Through circuit design and algorithm optimization, autonomous synchronization without the need for a GPS module has been successfully achieved, greatly reducing the hardware cost of the device; 3. The voltage-controlled crystal oscillator frequency adjustment method based on public network signal scanning also brings significant advantages in power consumption by removing the GPS module. The GPS module needs to continuously receive and process satellite signals during operation, which undoubtedly increases the energy consumption of the device. However, this technical solution uses an efficient synchronization algorithm and a low-power circuit design to effectively control the power consumption of the device while maintaining high-precision synchronization. This not only extends the battery life of the device, but also improves the overall energy efficiency of the device. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a flow chart of the method of the present invention. DETAILED DESCRIPTION

[0023] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0024] This application provides a technical solution, please refer to Figure 1 , a voltage-controlled crystal oscillator frequency adjustment method based on public network signal scanning, comprising: S1: Signal Scan The public network frequency band is scanned using a scanning system. The RF front-end component has sufficient bandwidth to cover all or part of the public network frequency band, so that it can receive wireless signals from different frequency points. During the scanning process, the received wireless signal is pre-processed, including filtering, amplification and analog-to-digital conversion, to extract effective signal components that may contain the synchronization signal of the target base station, and the pre-processed signal is analyzed to identify and capture the synchronization signal of the target base station.

[0025] S2: Signal Capture After successfully capturing the synchronization signal, the peak value is calculated, which reflects the degree of match between the synchronization signal and the locally generated reference signal. It is used to evaluate the strength and reliability of the signal. The relevant peak value of the synchronization signal and its position information in the time domain and / or frequency domain are recorded and output, including the specific time point when the synchronization signal appears, the frequency offset, and the relative position relative to the scanning starting point, thereby providing detailed information about the status of the target base station.

[0026] S3: Voltage Controlled Voltage Generation The carrier frequency deviation is extracted from the processed digital baseband signal. The carrier frequency deviation represents the difference between the received signal carrier frequency and the reference carrier frequency generated by the local oscillator. It extracts the continuous monitoring and analysis of the signal phase change, calculates the frequency error of the local crystal oscillator, converts the deviation value into the error percentage or absolute frequency deviation value relative to the nominal frequency of the local crystal oscillator, and outputs the frequency error information of the local crystal oscillator for subsequent calibration, compensation and recording.

[0027] S4: Voltage Control Voltage Adjustment Step S3: The PID controller is used as a core control unit to receive input signals and process the signals according to a preset control algorithm. The PID controller comprehensively considers the current frequency error of the system, the cumulative amount of the frequency error, and the rate of change of the frequency error, and generates the corresponding voltage-controlled voltage adjustment amount through accurate calculation. This adjustment amount has a high degree of accuracy and stability, and can ensure the precise control of the system output frequency. The DAC module, as a digital-to-analog conversion unit, is connected to the PID controller. The DAC module converts the voltage-controlled voltage adjustment amount in digital form generated by the PID controller into an analog signal form so that it can be subsequently loaded into the voltage-controlled end of the VCXO module. The DAC module has high precision and high stability, and can ensure the accuracy and reliability of the conversion process. The VCXO module, as a frequency output unit, has its voltage-controlled end connected to the output end of the DAC module. The VCXO module adjusts its output frequency according to the received analog voltage-controlled voltage adjustment amount. The VCXO module has a wide tuning range and good frequency stability, which can meet the system's precise requirements for output frequency. The input signal first enters the PID controller and is processed to generate a voltage-controlled voltage adjustment; then, the adjustment is converted into an analog signal through the DAC module; finally, the analog signal is loaded into the voltage-controlled end of the VCXO module to adjust its output frequency.

[0028] S5: Closed-loop feedback and enhanced stability Monitor the adjusted frequency convergence status in real time. This module evaluates the stability and accuracy of the frequency by continuously sampling and analyzing frequency data. If the frequency convergence status is monitored to exceed the preset threshold range, that is, the frequency deviation reaches or exceeds the predetermined limit, the system will immediately identify and respond to this abnormal situation. When the frequency convergence status is monitored to exceed the threshold in real time, the system will automatically trigger the resynchronization process. This process is designed to recalibrate and adjust the system frequency to ensure that it is consistent with the target frequency. The resynchronization process includes reinitializing the PID controller parameters, recalibrating the DAC module output, or making necessary adjustments to the VCXO module to quickly restore the frequency stability and accuracy of the system. During the operation of the system, if there is a loss of signal or transmission interruption, the system will automatically enable the hold mode. The hold mode is an emergency processing mechanism used to maintain the short-term stability of the system during signal loss. In the hold mode, the system will continue to maintain control of the VCXO module using historical data or preset backup parameters to ensure that the output frequency does not drift or fluctuate significantly before the signal is restored.

[0029] S6: Frequency protection The turned on electromagnetic field shielding equipment can not only effectively block electromagnetic noise and interference signals from the outside, but also suppress the electromagnetic radiation generated inside the system, thereby ensuring that the frequency signal inside the system remains pure and stable. This comprehensive protection mechanism enables the system to maintain high-performance frequency output in a complex electromagnetic environment. According to different application scenarios and frequency protection requirements, the structure, material or opening degree of the shielding equipment can be adjusted to achieve the best shielding effect.

[0030] Step S1: The synchronization signal includes a primary synchronization signal, a secondary synchronization signal, and a signal mode for base station identification and time synchronization. The primary synchronization signal is also used to achieve coarse time synchronization between the UE and the base station, laying the foundation for subsequent fine synchronization and channel estimation processes. The secondary synchronization signal is used in conjunction with the primary synchronization signal to achieve precise synchronization between the UE and the base station. After capturing the primary synchronization signal, the UE will further search for the secondary synchronization signal to improve signal accuracy, help the UE accurately identify the base station, and achieve precise time synchronization with the base station.

[0031] Step S3: Information is represented in digital form, including timestamp, deviation type and specific error value. The digitally represented frequency information can achieve higher accuracy and stability. The development of digital signal processing technology makes it possible to accurately control the frequency. The frequency can be fine-tuned through digital algorithms to achieve extremely high accuracy requirements. In communication, measurement and control systems, high-precision frequency sources are essential to ensure signal synchronization and improve the reliability and accuracy of data transmission. The voltage-controlled crystal oscillator can stably output a frequency signal that meets the requirements through digital control, so that the voltage-controlled crystal oscillator can easily communicate with other digital devices and realize automatic control. The digitally controlled voltage-controlled crystal oscillator can be easily integrated into various digital systems to improve the overall performance and reliability of the system.

[0032] Step S6: The electromagnetic field shielding device includes a metal shielding cover, which is configured outside the crystal oscillator. The metal shielding cover can ensure the accuracy of the crystal oscillator output frequency, thereby ensuring the correct execution of the system's timing logic, reducing data transmission errors or losses caused by unstable crystal oscillator frequency, and improving the system's communication performance.

[0033] Step S4: The PID controller is used to maintain the state stability of the controlled object and improve the control accuracy of the system, realize the automatic control and response speed of complex process parameters, and adjust the output of the controller according to the size of the current error. When the error is large, the output signal is also large, thereby speeding up the response speed of the controlled object. Proportional control can make the system approach the set value quickly, and adjust the output of the controller according to the amount of error accumulated over time. Eliminate the steady-state error of the system to ensure that the system eventually stabilizes near the set value. The role of integral control is similar to accumulating errors and continuously adjusting the output, and adjusting the output of the controller according to the rate of error change. Predict the future state change trend of the system, thereby reducing overshoot and improving the stability of the system. The introduction of differential control can suppress the oscillation of the system and adjust it according to the input and output data of the system, so it has strong adaptability and flexibility.

[0034] Step S4: The DAC module is a digital-to-analog converter, which is used to process the input digital signal, including filtering, amplification and digital signal processing algorithms. It is responsible for processing the input digital signal, such as filtering, amplification, digital signal processing algorithms, converting the digital signal into an analog signal, and generating the corresponding analog voltage or current according to the input digital code. It is responsible for filtering, amplifying and other processing of the output analog signal to ensure the quality and stability of the signal.

[0035] Step S5: Hold mode: The system uses previously collected data and model parameters to calculate the drift of the crystal oscillator output frequency and performs self-correction compensation. It uses the frequency drift model trained by historical data accumulated in the locked state to estimate the frequency output change trend and use the estimated value to compensate for the actual output frequency, thereby maintaining the frequency accuracy.

[0036] Step S5: The voltage-controlled voltage adjustment includes a pre-adjustment circuit, and when the signal is lost, the capacitance component, the current near the crystal and the temperature compensation are adjusted according to the system settings. The device is automatically adjusted through the pre-adjustment circuit, thereby greatly improving the overall automation of the device.

[0037] The scanning system includes a signal acquisition module, a synchronization error extraction module, a voltage-controlled voltage generation module, a VCXO module and a feedback control module, and the public network frequency band is scanned through the scanning system.

[0038] The signal acquisition module is used for data acquisition functions and signal conditioning and conversion. The synchronous error extraction module is used for error detection, error extraction and error correction. The voltage-controlled voltage generation module is used for voltage control, dynamic adjustment and improving system stability. The VCXO module is used to provide stable frequency signals and frequency control. The feedback control module is used to maintain system stability, improve control accuracy, enhance system robustness, achieve negative feedback and positive feedback and achieve automatic correction. The signal acquisition module usually includes amplifiers, filters, analog-to-digital converters and other circuits for signal enhancement, filtering and digital processing. The signal acquisition module is mainly responsible for signal reception and transmission to ensure the integrity and accuracy of the signal. The synchronous error extraction module can It can monitor the synchronization error between the received signal and the transmitted signal in real time. Through specific algorithms, such as the Gardner bit synchronization algorithm, the module can calculate the deviation between the received signal and the transmitted signal in time or phase. After detecting the synchronization error, the synchronization error extraction module can extract the error signal from the received signal. By adjusting the output frequency or phase of the digital control oscillator, the synchronization error between the received signal and the transmitted signal can be reduced, and the performance of the communication system can be improved. The voltage-controlled voltage generation module can achieve precise control of the output voltage. By adjusting the size of the control voltage, the value of the output voltage can be changed continuously and smoothly. It can quickly respond to changes in the external control voltage and realize dynamic adjustment of the output voltage. The core function of the VCXO module is to provide a stable frequency signal, using the high stability characteristics of the quartz crystal to generate a high-precision frequency signal. Through the control of the external voltage, the VCXO can fine-tune the output frequency within a certain range to meet the needs of different applications. By introducing the VCXO module, electronic equipment can achieve more precise frequency control and higher system performance.

[0039] VCXO can ensure the synchronization and correctness between various parts, reduce time deviation and jitter problems, and the feedback control module generates an error signal by comparing the system's output signal with the expected signal, and adjusts the input signal according to the error signal to stabilize the system near the expected output value. This mechanism can effectively cope with the parameter changes within the system and the interference of the external environment to ensure the stable operation of the system. By continuously measuring the output signal and comparing it with the expected signal, the feedback control module can adjust the input signal in real time, thereby reducing the output error of the system and improving the control accuracy. The feedback control module has strong robustness to the uncertainty of system parameters and external disturbances. The feedback control module can automatically adjust the control input according to the error signal so that the system output quickly approaches the expected value. In the control system, the feedback control module can realize two control modes: negative feedback and positive feedback. Negative feedback is used to stabilize the system output and reduce errors; while positive feedback is used to enhance the system output and improve the response speed of the system. The feedback control module selects the appropriate feedback mode in different application scenarios.

[0040] The extremely high synchronization accuracy can accurately meet the strict requirements of air interface synchronization. In the field of public network signal acquisition and processing, the accuracy of air interface synchronization is a key factor in ensuring data transmission stability and improving communication efficiency. This solution ensures a high degree of consistency between the local clock and the base station clock through an innovative synchronization mechanism, thereby effectively avoiding problems such as signal demodulation errors and reduced sampling efficiency caused by clock offset; While achieving high-precision synchronization, it completely eliminates the reliance on GPS modules. Traditional synchronization solutions often require the use of GPS signals to obtain accurate clock information, but this not only increases hardware costs, but also causes synchronization failures in indoor or blocked environments. This solution, through clever circuit design and algorithm optimization, successfully achieves autonomous synchronization without the need for a GPS module, greatly reducing the hardware cost of the device; Removing the GPS module also brings significant advantages in terms of power consumption. The GPS module needs to continuously receive and process satellite signals during operation, which undoubtedly increases the energy consumption of the device. However, this technical solution uses efficient synchronization algorithms and low-power circuit design to effectively control power consumption while maintaining high-precision synchronization. This not only extends the battery life of the device, but also improves the overall energy efficiency of the device.

[0041] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device.

[0042] Although the embodiments of the present application have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present application, and that the scope of the present application is defined by the appended claims and their equivalents.

Claims

1. A voltage-controlled crystal oscillator frequency adjustment method based on public network signal scanning, characterized in that: include: S1: Signal Scan The public network frequency band is scanned by using a scanning system, and the entire or partial range of the public network frequency band is covered by a radio frequency front-end component to receive wireless signals from different frequency points. During the scanning process, the received wireless signals are pre-processed, including filtering, amplification, and analog-to-digital conversion, and effective signal components containing synchronization signals of target base stations are extracted. The pre-processed signals are analyzed to identify and capture the synchronization signals of target base stations. S2: Signal Capture After successfully capturing the synchronization signal, calculate the peak value, which reflects the degree of match between the synchronization signal and the locally generated reference signal, evaluate the strength and reliability of the signal, record and output the relevant peak value of the synchronization signal and its position information in the time domain and frequency domain, including the specific time point when the synchronization signal appears, the frequency offset and the relative position relative to the scanning starting point, and provide detailed information about the status of the target base station; S3: Voltage Controlled Voltage Generation Extracting the carrier frequency deviation from the processed digital baseband signal, the carrier frequency deviation represents the difference between the received signal carrier frequency and the reference carrier frequency generated by the local oscillator, extracting the continuous monitoring and analysis of the signal phase change, calculating the frequency error of the local crystal oscillator, converting the deviation value into an error percentage or an absolute frequency deviation value relative to the nominal frequency of the local crystal oscillator, and outputting the frequency error information of the local crystal oscillator for subsequent calibration, compensation and recording; S4: Voltage Controlled Voltage Adjustment The information value obtained in step S3 is input into the PID controller to generate a voltage control voltage adjustment value, and the value is loaded into the voltage control terminal of the VCXO module through the DAC module to adjust the output frequency; S5: Closed-loop feedback and enhanced stability Monitor the frequency convergence status after adjustment in real time. If it exceeds the threshold, trigger the resynchronization process. When the signal is lost, enable the hold mode to keep the historical data stable for a short time. S6: Frequency protection Turn on the electromagnetic field shielding equipment to protect the frequency.

2. The voltage-controlled crystal oscillator frequency adjustment method based on public network signal scanning according to claim 1 is characterized in that: In step S1, the synchronization signal includes a primary synchronization signal, a secondary synchronization signal, and a signal mode for base station identification and time synchronization.

3. The voltage-controlled crystal oscillator frequency adjustment method based on public network signal scanning according to claim 1, characterized in that: In step S3, the information is represented in digital form, including a timestamp, a deviation type, and an error value.

4. The voltage-controlled crystal oscillator frequency adjustment method based on public network signal scanning according to claim 1, characterized in that: In step S6, the electromagnetic field shielding device includes a metal shielding cover, which is arranged outside the crystal oscillator.

5. The voltage-controlled crystal oscillator frequency adjustment method based on public network signal scanning according to claim 1, characterized in that: In step S4, the PID controller is used to maintain the state stability of the controlled object and improve the control accuracy of the system, and realize the automatic control and response speed of complex process parameters.

6. The voltage-controlled crystal oscillator frequency adjustment method based on public network signal scanning according to claim 1, characterized in that: In step S4, the DAC module is a digital-to-analog converter, which is used to process the input digital signal, including filtering, amplification and digital signal processing algorithms.

7. The voltage-controlled crystal oscillator frequency adjustment method based on public network signal scanning according to claim 1, characterized in that: In step S5, the holding mode is that the system calculates the drift of the crystal oscillator output frequency using previously collected data and model parameters, and performs self-correction compensation.

8. The voltage-controlled crystal oscillator frequency adjustment method based on public network signal scanning according to claim 1, characterized in that: In step S5, the voltage-controlled voltage adjustment includes a pre-adjustment circuit, and when the signal is lost, the capacitance component, the current near the crystal and the temperature compensation are adjusted according to the system settings.

9. The voltage-controlled crystal oscillator frequency adjustment method based on public network signal scanning according to claim 1, characterized in that: The scanning system includes a signal acquisition module, a synchronization error extraction module, a voltage-controlled voltage generation module, a VCXO module and a feedback control module.

10. The voltage-controlled crystal oscillator frequency adjustment method based on public network signal scanning according to claim 9, characterized in that: The signal acquisition module is used for data acquisition functions and signal conditioning and conversion, the synchronous error extraction module is used for error detection, error extraction and error correction, the voltage-controlled voltage generation module is used for voltage control, dynamic adjustment and improving system stability, the VCXO module is used to provide a stable frequency signal and frequency control, and the feedback control module is used to maintain system stability, improve control accuracy, enhance system robustness, realize negative feedback and positive feedback and realize automatic correction.

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