A regional wireless high-precision timekeeping and time dissemination system and method

Abstract

A regional wireless high-precision timekeeping and time transfer system and method of the present invention relate to the field of time synchronization, and include: a key display board for receiving user instructions and status display; a time-frequency processing board that receives a time acquisition instruction, converts an external standard time source into a local 1PPS signal, and then provides it to a chip atomic clock for clock taming. After time conversion, it provides Beidou time and a reference frequency for a navigation simulation board; the navigation simulation board encodes and modulates navigation messages based on set signal generation parameters, Beidou time, and the reference frequency to generate an analog Beidou navigation signal, and sends it to a transmitting antenna; the transmitting antenna transmits the analog Beidou navigation signal to a ground Beidou receiver device; a power supply module performs power conversion on a battery; and an integrated control board performs data interaction and status power consumption management. The present invention realizes fast and efficient time transfer to Beidou user equipment through a wireless broadcast method, and has a long battery life for timekeeping days and high timekeeping accuracy.

Description

Technical Field

[0001] The present invention relates to the technical field of time synchronization, and in particular to a regional wireless high-precision timekeeping and time dissemination system and method. Background Art

[0002] In contemporary communication systems, time synchronization accuracy is a core technical indicator to ensure data transmission, network collaboration, and service quality. The dependence of distributed systems on time dissemination accuracy is even more critical, and precise time synchronization has become an important support for the development of the industry's science and technology.

[0003] The Beidou navigation signal reception requires precise time information. When the Beidou user equipment captures the long code, it needs to rely on the local precise time for chip synchronization. The time deviation between the Beidou user equipment and the satellite signal must be less than ±1 second to ensure the capture synchronization of the long code signal.

[0004] For the all-weather ±1 second time accuracy requirement of the Beidou user equipment, there are currently two main solutions.

[0005] (1) The RTC timekeeping solution inside the Beidou user equipment: When the Beidou user equipment powers on to capture the long code, it obtains the reference time from the local RTC chip. The disadvantage of this RTC timekeeping solution is the low timekeeping accuracy. After 5.8 days of timekeeping, the timekeeping accuracy exceeds ±1 second, and it cannot support the Beidou long code capture work.

[0006] (2) The time dissemination solution using an external time synchronization device: When the Beidou user equipment powers on to capture the long code, it first obtains the time information from the external time synchronization device through the serial port. The disadvantage of this solution is that the power-off timekeeping endurance time of the external time synchronization device is too short, only maintaining for 24 hours, and it cannot support the high-precision time service required for the Beidou user equipment to power on at any time. Summary of the Invention

[0007] The main purpose of the present invention is to overcome the above defects in the prior art, and propose a regional wireless high-precision timekeeping and time dissemination system and method. Through the cooperation of a comprehensive control board, a time-frequency processing board, a navigation simulation board, a key display board, a power module, and a transmitting antenna, time acquisition, timekeeping, and fast and efficient time dissemination to the Beidou user equipment are realized through wireless broadcast. It has the characteristics of long endurance time and high timekeeping accuracy, and effectively solves the problem that the Beidou user equipment cannot reliably perform long code direct capture due to poor internal timekeeping accuracy.

[0008] The present invention adopts the following technical solutions:

[0009] On the one hand, a regional wireless high-precision timekeeping and time dissemination system includes: a comprehensive control board, a time-frequency processing board, a navigation simulation board, a key display board, a power module, and a transmitting antenna;

[0010] The button display board is used to receive user input instructions and send them to the integrated control board, and is also used to receive the status information monitored by the integrated control board and display it.

[0011] The time-frequency processing board is used to receive the time acquisition instruction input by the user sent by the integrated control board, obtain the external standard time source signal through the integrated control board, process it to obtain the local 1PPS+ToD signal, provide the local 1PPS signal to the chip atomic clock for clock taming to obtain the reference frequency, convert the local ToD signal to obtain the Beidou time, and provide the reference frequency and Beidou time to the navigation simulation board through the integrated control board.

[0012] The navigation simulation board is used to receive the Beidou time and reference frequency sent by the integrated control board; based on the set signal generation parameters, Beidou time and reference frequency, perform navigation message encoding and modulation to generate an analog Beidou navigation signal, and send it to the transmitting antenna.

[0013] The transmitting antenna is used to transmit the analog Beidou navigation signal to the ground Beidou receiver device.

[0014] The power supply module is used to perform power conversion and supply power to the battery.

[0015] The integrated control board is used to be respectively connected to the button display board, the time-frequency processing board, the navigation simulation board and the power supply module for data interaction and power consumption management.

[0016] Preferably, the time-frequency processing board includes a 1PPS signal processing module and a B-code decoding module, and also includes a chip atomic clock; the external standard time source signal includes a 1PPS+ToD signal and a B-code signal; the 1PPS signal processing module receives the 1PPS+ToD signal, and uses a low-power MCU chip and a high-precision 1PPS phase discrimination chip to implement local 1PPS signal processing to obtain the first local 1PPS+ToD signal; the B-code decoding module receives the B-code signal and performs decoding processing to obtain the second local 1PPS+ToD signal; the first local 1PPS signal or the second local 1PPS signal is provided to the chip atomic clock for clock taming to obtain the reference frequency; the 1PPS signal processing module performs time conversion on the first local ToD signal and the second local ToD signal to obtain the Beidou time, and provides the Beidou time and the reference frequency to the navigation simulation board through the integrated control board.

[0017] Preferably, the navigation simulation board includes a signal control unit, a navigation signal modulation and simulation unit, a clock source circuit, and a radio frequency power amplifier unit; the signal control unit performs navigation message encoding based on set signal generation parameters and the reference frequency output by the time-frequency processing board received; the clock source circuit generates a modulation reference frequency for the navigation signal modulation and simulation unit; the navigation signal modulation and simulation unit modulates the encoded navigation message to generate an analog Beidou navigation signal; the radio frequency power amplifier circuit processes the analog Beidou navigation signal and sends it to the transmitting antenna.

[0018] Preferably, the comprehensive control board includes a time-frequency control unit, a navigation control unit, a human-computer interaction unit, and a power consumption control unit; the time-frequency control unit is connected to the time-frequency processing board for data interaction; the navigation control unit is connected to the navigation simulation board for data interaction; the human-computer interaction unit is connected to the button display board for data interaction; the power consumption control unit is connected to the human-computer interaction unit, and when receiving a standby instruction input by the user or detecting no operation within a preset time, performs power consumption management on the power output by the power supply module.

[0019] Preferably, when receiving a standby instruction input by the user or detecting no operation within a preset time, performing power consumption management on the power output by the power supply module, specifically including:

[0020] When the comprehensive control board receives a standby instruction input by the user or the comprehensive control board detects no operation within a preset time, the power consumption control unit will disconnect all the power of the navigation simulation board, part of the power of the time-frequency processing board, part of the power of the comprehensive control board, and the power of the liquid crystal screen.

[0021] Preferably, the transmitting antenna uses a microstrip antenna.

[0022] Preferably, the regional wireless high-precision timekeeping and time service system further includes: an aviation plug-in; the aviation plug-in is respectively connected to the comprehensive control board and an external standard time source device, the external standard time source device is used to provide an external standard time source signal, and the comprehensive control board sends the external standard time source signal to the time-frequency processing board.

[0023] Preferably, the power supply module uses a DC-DC conversion chip.

[0024] On the other hand, a regional wireless high-precision timekeeping and time service method, based on the timekeeping and time service system, the method includes:

[0025] Time synchronization and timekeeping maintenance steps, the time-frequency processing board tames the local chip atomic clock by tracking the external standard time source signal, and after disconnecting the external time source signal, the system will enter the atomic clock start timekeeping stage and continuously output a high-precision clock signal; the comprehensive control board monitors the working states of the time-frequency processing board and the atomic clock in real time;

[0026] Navigation signal generation and modulation output step: The integrated control board sets the signal generation parameters of the navigation simulation board according to the user instructions; the navigation simulation board encodes and modulates the navigation message in combination with the timing signal based on these parameters to generate an analog Beidou navigation signal, which is output to the transmitting antenna after amplification and filtering processing;

[0027] Signal transmission and status monitoring step: The transmitting antenna transmits the navigation signal according to the set parameters; the integrated control board collects the working status data of each part in the timing and time service system in real time and displays it to the user through the key display board;

[0028] Standby timing step: After detecting no operation within the preset time or receiving the user standby instruction, the integrated control board performs low-power management to keep the chip atomic clock and related circuits running, and cuts off the power supply of the rest of the circuits. The system enters the high-precision timing state and waits to be woken up for the next use.

[0029] Preferably, before the time synchronization and timing maintenance step, there is also a startup initialization step as follows:

[0030] After the system is powered on, the integrated control board first performs a system self-check to detect the connection status and working parameters of each part of the hardware, and at the same time initializes the internal software program and configures the initial working mode of each part; the time-frequency processing board is in a free-running state, waiting for the user to perform a time acquisition operation, the navigation simulation board loads the pre-stored navigation signal configuration file, and the transmitting antenna enters the standby state for transmission.

[0031] As can be seen from the above description of the present invention, compared with the prior art, the present invention has the following beneficial effects:

[0032] (1) The present invention is composed of an integrated control board, a time-frequency processing board, a navigation simulation board, a key display board, a power module, a lithium battery and a transmitting antenna. By adopting the design of the time-frequency processing board, navigation simulation board and integrated control board based on the chip atomic clock, it realizes the performance of low power consumption and high-precision timing. At the same time, it can provide high-precision wireless time service to regional Beidou user equipment through navigation analog signals. Compared with the existing RTC timing and time synchronization equipment serial port timing scheme, it shows obvious advantages in terms of timing accuracy, battery life and usage efficiency;

[0033] (2) The time-frequency processing board of the present invention includes a 1PPS signal processing module and a B-code decoding module. It can provide the reference frequency and Beidou time obtained through the 1PPS signal processing module to the navigation simulation board for use, or provide the reference frequency and Beidou time obtained through the B-code decoding module to the navigation simulation board for use. The 1PPS signal processing module and the B-code decoding module can play a redundant role to ensure the stability of time service and do not affect the use of Beidou user equipment when one of the modules fails or deviates.

[0034] (3) The integrated control board of the present invention includes a power consumption control unit; the power consumption control unit is connected to the human-machine interaction unit. When receiving a standby instruction input by the user or detecting no operation within a preset time, the power consumption control unit performs low-power management, keeps the chip atomic clock and related circuits running, cuts off the power supply of the remaining circuits, the system enters a high-precision timekeeping state, waits to be woken up for use next time, and extends the battery life. Description of the Drawings

[0035] Figure 1 is the structural block diagram of the regional wireless high-precision timekeeping and time dissemination system of this embodiment of the present invention;

[0036] Figure 2 is the flow schematic diagram of the regional wireless high-precision timekeeping and time dissemination method of this embodiment of the present invention. Detailed Embodiments

[0037] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the drawings in the embodiments of the present invention; obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0038] In the description of the present invention, it should be noted that the terms "include", "comprise" or any other variant thereof are intended to cover a non-exclusive inclusion, so that a process, method, article or device including a series of elements not only includes those elements, but also includes other elements not expressly listed, or further includes elements inherent to such process, method, article or device. Without further limitations, the element defined by the statement "including a..." does not exclude the existence of additional identical elements in the process, method, article or device including the element.

[0039] In the description of the present invention, it should be noted that the flowcharts shown in the drawings are only illustrative examples, not necessarily including all the content and operations / steps, nor necessarily executed in the described order. For example, some operations / steps can also be decomposed, combined or partially merged, so the actual execution order may be changed according to the actual situation.

[0040] See Figure 1 As shown, a regional wireless high-precision timekeeping and time dissemination system of the present invention includes an integrated control board 1, a time-frequency processing board 2, a navigation simulation board 3, a button display board 4, a power module 5 and a transmitting antenna 6;

[0041] The button display board 4 is used to receive user input instructions and send them to the integrated control board 1, and is also used to receive the status information monitored by the integrated control board 1 and display it.

[0042] The time-frequency processing board 2 is used to receive the time acquisition instruction input by the user sent by the integrated control board 1, obtain the external standard time source signal through the integrated control board 1, process it to obtain the local 1PPS+ToD signal, provide the local 1PPS signal to the chip atomic clock 22 for clock taming to obtain the reference frequency, convert the local ToD signal to obtain the Beidou time, and provide the reference frequency and Beidou time to the navigation simulation board 3 through the integrated control board 1.

[0043] The navigation simulation board 3 is used to receive the Beidou time and reference frequency sent by the integrated control board 1; based on the set signal generation parameters, Beidou time and reference frequency, perform navigation message encoding and modulation to generate an analog Beidou navigation signal, and send it to the transmitting antenna 6.

[0044] The transmitting antenna 6 is used to transmit the analog Beidou navigation signal to the ground Beidou receiver device.

[0045] The power module 5 is used to perform power conversion and supply power to the lithium battery 7.

[0046] The integrated control board 1 is used to be respectively connected to the button display board 4, the time-frequency processing board 2, the navigation simulation board 3 and the power module 5 for data interaction and power consumption control.

[0047] In this embodiment, the time-frequency processing board 2 is the core processing unit of the time signal, and uses the low-power chip atomic clock 22, the 1PPS signal processing module 20 and the B-code decoding module 21 to realize time signal tracking and synchronization, local timekeeping and timing output, and provide high-precision time and frequency reference for the navigation simulation board 3; the navigation simulation board 3, as the Beidou navigation signal generation unit, has the functions of Beidou navigation signal simulation, signal modulation and amplification output. By receiving the 1PPS+ToD signal from the time-frequency processing board 2, it modulates this time information into a Beidou navigation signal and uses the transmitting antenna 6 to complete the broadcast of the Beidou navigation signal; the integrated control board 1, as the control unit of the system, mainly completes the parameter configuration, status query and low-power management of each part of the system; the power module 5 provides the working voltage for the stable operation of the whole machine system.

[0048] The working principle of a regional wireless high-precision timekeeping and time dissemination system of the present invention is as follows. The time-frequency processing board 2 obtains accurate time information from an external standard time source. After being processed by an internal high-precision clock chip (1PPS signal processing module 20 and B-code decoding module 21), it is transmitted to the chip atomic clock 22 circuit for timekeeping. Relying on its excellent frequency stability, the chip atomic clock 22 maintains a high-precision time reference, providing an accurate time reference for subsequent navigation signal generation. The navigation simulation board 3 receives the 1PPS+ToD timekeeping signal from the time-frequency processing board 2. According to the preset Beidou satellite navigation message data, it encodes and modulates this time information, converting it into a radio frequency signal that conforms to the satellite navigation standard. This process strictly follows the modulation specifications of satellite navigation signals to ensure the accuracy of key elements such as the frequency characteristics and code structure of the signal. The modulated navigation signal is output from the navigation simulation board 3 to the transmitting antenna 6, which broadcasts it into space in the form of electromagnetic waves, simulating the process of a satellite transmitting navigation signals to ground receiver devices, for Beidou receivers to capture, track, and demodulate, realizing the simulation and reproduction of a real satellite navigation scenario.

[0049] Specifically, the time-frequency processing board 2 includes a 1PPS signal processing module 20 and a B-code decoding module 21, and also includes a chip atomic clock 22 and a first power supply and interface circuit 23; the external standard time source signal includes a 1PPS+ToD signal and a B-code signal; the 1PPS signal processing module 20 receives the 1PPS+ToD signal, and uses an ultra-low-power MCU chip and a high-precision 1PPS phase discriminator chip to implement local 1PPS signal processing, obtaining a first local 1PPS+ToD signal; the B-code decoding module 21 receives the B-code signal and performs decoding processing, obtaining a second local 1PPS+ToD signal; providing the first local 1PPS signal or the second local 1PPS signal to the chip atomic clock 22 for clock taming to obtain a reference frequency, ensuring the stable operation of the chip atomic clock 22, realizing the nanosecond-level high-precision timekeeping function, and providing a reliable time reference for the entire system; the 1PPS signal processing module 20 performs time conversion on the first local ToD signal and the second local ToD signal to obtain Beidou time, and provides Beidou time and reference frequency to the navigation simulation board 3 through the integrated control board 1; the first power supply and interface circuit 23 is connected to the integrated control board 1. In addition, the 1PPS signal processing module 20 also includes a ToD signal. After the clock taming is completed, the ToD signal goes to "Y", and only then is the Beidou time and reference frequency provided for use by the simulated navigation board.

[0050] The low-power MCU chip can be an ultra-low-power chip of the GD32L series, and the high-precision 1PPS phase discriminator chip can be a high-precision time interval measurement TDC chip of the MS1 series. It should be noted that in this embodiment, the model is not specifically limited, as long as it can achieve ultra-low power consumption and high precision.

[0051] The low-power MCU chip includes a 1PPS generation module, a 1PPS phase discrimination control module, a PID control module, a temperature compensation module, and a time conversion module. The 1PPS generation module obtains an external standard 1PPS+ToD signal, and after being processed by a timer circuit, generates a local 1PPS signal and a delayed 1PPS signal. The local 1PPS signal is output to the time conversion module, and the delayed 1PPS signal is output to the 1PPS phase discrimination chip; the 1PPS phase discrimination control module controls the 1PPS phase discrimination chip to compare the external standard 1PPS signal and the delayed 1PPS signal to obtain a phase difference value; the PID control module adjusts the voltage control value of the chip atomic clock 22 according to the phase difference value; the temperature compensation module performs frequency compensation on the chip atomic clock 22 according to the real-time detected ambient temperature; the chip atomic clock 22 provides a reference clock for the low-power MCU chip; the time conversion module converts the ToD signal into Beidou time to time the Beidou user equipment.

[0052] Specifically, the 1PPS generation module can be generated by a hardware timer circuit inside the low-power MCU chip and has the characteristic of accurate counting. To achieve the accurate generation of the 1PPS signal, it is completely implemented by the MCU hardware timer circuit. The general timer of the MCU chip in this embodiment is 16-bit, the timer time base frequency is 40MHz, the resolution is 25ns, and the maximum timing is up to 1.6ms and cannot time to 1s. Therefore, a two-stage timer cascade method is adopted. The first timer TIMER1 is configured with a count of 40000 to generate a 1ms cycle timing, triggering the second timer TIMER2 and the third timer TIMER3. Both TIMER2 and TIMER3 are configured with a count of 1000 to trigger the PWM to generate a 1Hz signal, that is, to implement the local 1PPS output function, where TIMER2 generates the local 1PPS signal. TIMER3 is provided for the phase discriminator to output with a delay of 1ms according to the requirement of the phase discrimination for the lagging timing of the measured signal, providing a measured delayed 1PPS signal for the 1PPS phase discrimination chip.

[0053] The 1PPS phase discrimination control module can be a software program inside the low-power MCU chip, mainly to control the 1PPS phase discrimination chip. Specifically, a control signal is generated when obtaining the external standard 1PPS+ToD signal, completing the measurement of the time delay value of the two input 1PPS signals (the external standard 1PPS signal and the delayed 1PPS signal) by the 1PPS phase discrimination chip, and reading the test data through the SPI interface.

[0054] The phase discrimination of the 1PPS signal mainly compares the externally input standard 1PPS with the locally generated delayed 1PPS signal, and measures the deviation between the two input 1PPS signals through a high-precision TDC chip. Since the TDC chip can only measure two signals with a phase difference within a certain range, the measurement range selected in the present invention is from 500 ns to 4 ms. Therefore, the 1PPS signal output by the local third timer TIMER3 is delayed by 1 ms to ensure that the timing of the standard 1PPS and the locally generated 1PPS signal meets the measurement requirements. Connect the external standard 1PPS signal to the START pin of the TDC chip, connect the delayed 1PPS signal to the STOP1 pin of the chip, and enable the chip to start signal measurement by controlling the enable signals EN_START, EN_STOP and the reset signal RSTN through the MCU. Read the measurement result through the SPI interface between the MCU chip and the TDC chip, and the measured phase difference can be obtained.

[0055] The PID control module can be implemented through the internal software program of the low-power MCU chip. It mainly calculates the phase discrimination value (phase difference value) of the 1PPS signal into a voltage adjustment value through the PID control algorithm, and operates the DAC chip through the 10SPI interface of the low-power MCU chip to realize the frequency adjustment of the chip atomic clock 22.

[0056] The PID control algorithm is mainly used to achieve the purpose of frequency calibration by changing the voltage-controlled value of the atomic clock, and adjusts the voltage-controlled value u of the atomic clock according to the phase difference output by the phase discriminator k , to reach a dynamic equilibrium state. Since the calculation amount of the PID control algorithm is small and the algorithm complexity is relatively low, it is suitable for software operation of ultra-low-power MCU chips. The algorithm formula is as follows:

[0057]

[0058] Among them, Δu k is the voltage control difference; u k is the voltage control value at the current moment; u k-1 is the voltage control value at the previous moment; T is the sampling period; e k is the phase difference at the current moment; e k-1 is the average value of the phase differences in the previous time period; e k-2 is the average value of the phase differences in the previous two time periods; K p is the proportionality coefficient; T i is the differential coefficient; T d is the integral coefficient.

[0059] The sampling period of this embodiment is 5 seconds, the voltage control value changes once every 5 seconds, and the finally obtained Δu kis the difference between the current voltage control and the previous voltage control. In the PID control algorithm, the role of proportional regulation is to instantaneously respond to the deviation between the expected value and the current value. When the proportional coefficient is larger, the regulation strength is greater, and the control parameters are more stable. Conversely, when the proportional coefficient is smaller, the control parameters are more prone to oscillation. Integral regulation is used to accumulate and eliminate the residual error generated by the proportional regulation link and usually acts together with proportional regulation. The differential part mainly regulates the change speed of the deviation to prevent the change of the deviation. In this embodiment, the PID coefficients are set in two stages. In the initial synchronization stage, the proportional coefficient K p is 3.8, and the differential coefficient T i is 1.2, and the integral coefficient T d is 0.3. After synchronization and stabilization, the proportional coefficient K p is 3.5, and the differential coefficient T i is 1.1, and the integral coefficient T d is 0.25, which can calibrate the frequency accuracy of the chip atomic clock 22 at the order of 5E-12.

[0060] The temperature compensation module can be implemented through the internal software program of the MCU chip, mainly to establish the curve relationship between the temperature value and the frequency value within the working temperature range and perform real-time temperature measurement and frequency compensation during the operation of the terminal. For the frequency accuracy index of the atomic clock, temperature is the most important influencing factor, and the repeatability of the influence of temperature on the atomic clock frequency is relatively good. During the entire service life cycle of the atomic clock, the temperature characteristics are basically constant. Therefore, in the present invention, the temperature variation characteristics of the frequency index of the chip atomic clock 22 are tested, a temperature compensation model is established based on the test data, and a compensation algorithm is written to compensate for the temperature drift. The temperature compensation formula is:

[0061]

[0062] where A i is the temperature compensation coefficient, obtained by fitting, i ∈ [1, 5]; T w is the ambient temperature at which the chip atomic clock 22 operates; f(T w ) is the frequency value at temperature T w ; T ref is the reference temperature; f(T ref ) is the frequency value at the reference temperature T ref .

[0063] During specific implementation, temperature compensation parameter sampling can be carried out before the product leaves the factory. The temperature of the atomic clock circuit is raised and lowered using a temperature change test chamber. By controlling the temperature change, the output frequency of the atomic clock is measured to obtain the corresponding data of frequency and temperature and the sampling time. This data is used for modeling to obtain the temperature compensation model curve of the atomic clock, which serves as the key data for the timekeeping algorithm processing, thereby realizing frequency deviation compensation of the atomic clock when the environmental temperature changes and improving the timekeeping accuracy index of the atomic clock.

[0064] The navigation simulation board 3 includes a signal control unit 30, a navigation signal modulation and simulation unit 31, a clock source circuit 32, a radio frequency power amplifier unit 33, and a second power supply and interface circuit 34. The signal control unit 30 performs navigation message encoding based on the set signal generation parameters and the reference frequency output by the time-frequency processing board 2 received. The clock source circuit 32 generates a modulated reference frequency for the navigation signal modulation and simulation unit 31. The navigation signal modulation and simulation unit 31 modulates the encoded navigation message to generate an analog Beidou navigation signal. The radio frequency power amplifier circuit processes the analog Beidou navigation signal and then sends it to the transmitting antenna 6. The second power supply and interface circuit 34 is connected to the integrated control board 1.

[0065] In this embodiment, the signal control unit 30 can use a dedicated navigation signal processor DSP chip. This processor DSP chip has powerful floating-point operation capabilities and is used to quickly complete complex signal processing tasks such as navigation message encoding. It has an on-board large-capacity memory for storing data such as navigation satellite orbit parameters and message templates, and supports the simulation generation of signals of multiple satellite navigation systems. The radio frequency power amplifier circuit of the signal output channel uses a high-linearity amplifier and filter to ensure that the output signal quality meets the test requirements of satellite receivers.

[0066] The integrated control board 1 includes a time-frequency control unit 10, a navigation control unit 11, a human-machine interaction unit 13, a power consumption control unit 12, a power management unit 14, and a protection circuit 15. The time-frequency control unit 10 is connected to the time-frequency processing board 2 for data interaction. The navigation control unit 11 is connected to the navigation simulation board 3 for data interaction. The human-machine interaction unit 13 is connected to the button display board 4 for data interaction. The power consumption control unit 12 is connected to the human-machine interaction unit 13 and performs power consumption management on the power supply output by the power module 5 when receiving a standby instruction input by the user or detecting no operation within a preset time. The power management unit 14 monitors parameters such as battery power and voltage in real time, controls the working state of the power on / off charging management chip, and ensures stable power supply for the system. The protection circuit 15 protects the integrated control board 1 to prevent damage.

[0067] Further, when receiving a standby instruction input by the user or detecting no operation within a preset time, power consumption management is performed on the power output by the power module 5, which specifically includes:

[0068] When the integrated control board 1 receives a standby instruction input by the user or the integrated control board 1 detects no operation within a preset time, the power consumption control unit 12 will disconnect all the power supplies of the navigation simulation board 3, part of the power supplies of the time-frequency processing board 2, part of the power supplies of the integrated control board 1, and the power supply of the liquid crystal screen.

[0069] In this embodiment, the integrated control board 1 uses a low-power microcontroller MCU as the main control chip, which is responsible for the overall machine function control, human-computer interaction, and low-power management. It integrates UART, SPI, and I2C communication interfaces to realize data interaction with each functional module. The button display board 4 is connected to the low-power microcontroller MCU through a matrix scanning circuit, providing an interface for the user to input instructions and view the system status.

[0070] The button display board 4 includes a liquid crystal screen 40, buttons 41, and indicator lights 42 for status display prompts and user input.

[0071] The transmitting antenna 6 selects a high-gain, wide-band, and miniaturized microstrip antenna, which has good radiation characteristics and directivity, and can effectively transmit navigation signals to the specified area. The antenna design takes into account the compatibility of satellite navigation frequency bands to ensure high-efficiency transmission performance when simulating signals of different satellite systems. At the same time, lightweight materials and a compact structure are used to facilitate the portable use of the device.

[0072] The power module 5 selects a high-efficiency DC-DC conversion chip to stably convert the output voltage of the lithium battery into voltages such as 12V and 5V required by each hardware module to ensure power supply stability. The lithium battery uses a high-energy-density lithium polymer battery, and its capacity is designed according to the system power consumption and endurance requirements. It has overcharge, over-discharge, and short-circuit protection functions to ensure the safe and reliable use of the battery and meet the long-term working requirements of the device in outdoor and other scenarios without external power supply.

[0073] In this embodiment, the regional wireless high-precision timekeeping and time service system further includes: an aviation plug 8; the aviation plug 8 is respectively connected to the integrated control board 1 and an external standard time source device, and the external standard time source device is used to provide an external standard time source signal, and the integrated control board 1 sends the external standard time source signal to the time-frequency processing board 2.

[0074] In addition to the above-mentioned hardware design, the integrated control board 1, the time-frequency processing board 2, and the navigation simulation board 3 of the regional wireless high-precision timekeeping and time service system of this embodiment also include software design.

[0075] The overall software adopts a hierarchical architecture design, which is divided into the underlying hardware driver layer, the intermediate functional module layer, and the upper application layer. The underlying hardware driver layer writes driver programs for each hardware module such as the time-frequency processing board 2, the navigation simulation board 3, and the button display board 4 to achieve direct operation and control of hardware resources; the intermediate functional module layer encapsulates core functional modules such as time synchronization, signal generation, and power consumption management, providing a standardized interface for the upper application; the upper application layer faces user operations and realizes functions such as human-computer interaction interface design, system parameter configuration, and work process control, facilitating user use and system maintenance and upgrade.

[0076] Specifically, the software implementation includes the time synchronization and timekeeping software process, the navigation signal generation software process, and the comprehensive control software process.

[0077] The specific implementation of the time synchronization and timekeeping software process is as follows.

[0078] After the time-frequency processing board 2 is powered on and initialized, the software first configures the parameters of the external time input interface (such as 1PPS+ToD and B-code signal configuration, 1PPS+ToD level RS422 and RS232 configuration, B-code signal time system configuration as UTC time or Beijing time), and starts the time synchronization protocol parsing program; after the time-frequency processing board 2 receives the external time signal, it parses and extracts the accurate time information, calibrates the local time, and transmits it to the chip atomic clock 22 for clock taming; when the time-frequency processing board 2 detects that the status of the chip atomic clock 22 is tamed and locked, the system prompts "Can enter the timekeeping mode" on the LCD screen interface; during the timekeeping process, the comprehensive control board 1 can monitor the drift of the chip atomic clock 22, the battery power, and the system working duration (starting to count after being tamed and locked) in real time, and issue corresponding alarm prompts such as "Low timekeeping accuracy, request time", "Low battery, please charge", and "Large timekeeping deviation, please obtain time!" according to the data.

[0079] The specific implementation of the navigation signal generation software process is as follows.

[0080] After the navigation simulation board 3 receives the 1PPS+ToD signal and control instructions sent by the comprehensive control board 1, it reads the pre-stored navigation satellite parameter data from the memory, and based on the 10MHz signal provided by the time-frequency processing board 2, encodes the navigation message according to the signal system specifications of the corresponding satellite navigation system. After the encoding is completed, the modulation module modulates the carrier signal according to the set BPSK modulation method to generate an analog navigation signal. The software monitors the navigation signal simulation status, the baseband chip temperature status, the power amplifier on status, and the RF signal transmission power in real time during the signal generation process, and alarms for abnormal situations to ensure the reliability of the output signal.

[0081] The specific implementation of the comprehensive control software process is as follows.

[0082] After the integrated control board 1 is powered on, it first runs the system self-check program to detect the connection status and working parameters of each hardware module (performing basic function detection on each independent part through the serial port, including whether the serial port information of the 1PPS signal processing module 20, chip atomic clock 22, B-code decoding module 21, navigation simulation board 3, etc. of the time-frequency processing board 2 is normal), and displays the self-check result. During the operation of the system, the software periodically collects the status information of each module through the serial port, and controls the corresponding function modules according to the user key instructions and the system working status to implement functions such as time acquisition operation, autonomous timing, signal simulation control, signal power control, power amplifier switch control, and power consumption management. At the same time, according to the low-power strategy, the software turns off the power of some non-essential hardware modules during the idle period of the system to reduce the power consumption of some circuits and extend the battery life.

[0083] See Figure 2 As shown, the present invention further includes a regional wireless high-precision timing and time service method. Based on the timing and time service system, the method includes:

[0084] Start the initialization step S201. After the system is powered on, the integrated control board first performs a system self-check to detect the connection status and working parameters of each part of the hardware, and at the same time initializes the internal software program and configures the initial working mode of each part; the time-frequency processing board is in a free-running state (the free-running state means that the system starts up without any time reference, is in a random time, and is in an unavailable state), waiting for the user to perform a time acquisition operation, the navigation simulation board loads the pre-stored navigation signal configuration file, and the transmitting antenna enters the waiting-to-transmit state. The navigation signal configuration file refers to the navigation simulation signal simulation file, and its content includes Beidou satellite ephemeris, almanac, ionospheric parameters, tropospheric parameters, leap second information, etc.

[0085] Time synchronization and timekeeping maintenance step S202: The time-frequency processing board tames the local chip atomic clock by tracking the external standard time source signal, improving the frequency accuracy of the chip atomic clock to the order of 1E-12 (the time-frequency processing board receives the 1PPS+ToD signal from the external time source device, uses the 1PPS signal to tame the chip atomic clock inside the time-frequency processing board, enables the atomic clock to reach a frequency accuracy of 1E-12, and has the ability of high-precision timekeeping. At the same time, the UTC time information is parsed from the ToD signal, that is, the process of tracking the external time source signal is completed). After disconnecting the external time source signal, the system will enter the atomic clock startup timekeeping stage and continuously output high-precision clock signals. The integrated control board monitors the working states of the time-frequency processing board and the atomic clock in real time (the monitoring content includes the locking state of the chip atomic clock: unlocked, physically locked, and tamed locked. When it is unlocked and physically locked, it is not available and cannot be provided to the navigation simulation board. Only after being tamed locked can it be used by the navigation simulation board. At the same time, the valid flag of the ToD signal output by the time-frequency processing board is "Y", that is, it can only be provided to the navigation simulation board when it is valid), ensuring the stability and reliability of the time reference and providing precise timing guarantee for the generation of navigation signals.

[0086] Navigation signal generation and modulation output step S203: The integrated control board sets the signal generation parameters of the navigation simulation board according to the user's instructions, including the number of simulated satellites, transmitted signal strength, transmitted frequency points, time information, etc. The navigation simulation board encodes and modulates the navigation message based on these parameters and in combination with the timekeeping signal to generate a simulated Beidou navigation signal, which is output to the transmitting antenna after processing such as amplification and filtering.

[0087] Signal transmission and status monitoring step S204: The transmitting antenna transmits the navigation signal according to the set parameters such as frequency and power. The integrated control board collects the working state data of each part in the timekeeping and time service system in real time, including power supply voltage, signal strength, temperature, etc., and displays it to the user through the key display board, facilitating the user to understand the system operation situation. At the same time, the integrated control board performs low-power management based on the monitoring data and dynamically adjusts the working states of each module to extend the battery life.

[0088] Standby timekeeping step S205: After detecting no operation within the preset time or receiving the user's standby instruction, the integrated control board performs low-power management, keeps the chip atomic clock and related circuits running, and cuts off the power supply of the rest of the circuits. The system enters the high-precision timekeeping state and waits to be woken up for the next use.

[0089] The integrated control board will enter the low-power management when it detects two situations: First, when the integrated control board receives an instruction sent by the user through the button to enter the low-power state, the power management system will cut off all the power of the navigation simulation board, part of the power of the time-frequency processing board, part of the power of the integrated control board, and the power of the liquid crystal display screen; Second, when the integrated control board monitors that the device has not been used for a long time and reaches the sleep trigger time, it will enter the low-power state, and the power management system will cut off all the power of the navigation simulation board, part of the power of the time-frequency processing board, part of the power of the integrated control board, and the power of the liquid crystal display screen. In the low-power operation state, the device only retains the chip atomic clock and part of the power supply and interface chips running, and the rest are in the power-off state.

[0090] As described above, the present invention can provide high-precision time synchronization services for Beidou user equipment. Through the modular hardware architecture and intelligent software management, it realizes low-power, high-precision time signal processing and broadcasting. The battery can maintain timekeeping for up to 30 days when fully charged, and the timekeeping accuracy is ±5 milliseconds. It realizes fast and efficient time service for Beidou user equipment through wireless broadcast.

[0091] The above is only a preferred specific embodiment of the present invention; however, the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention, according to the technical solution and its improvement concept of the present invention, makes equivalent substitutions or changes, and all should be covered by the protection scope of the present invention.

Claims

1. A regional wireless high-precision timekeeping and time dissemination system, characterized in that Comprising: An integrated control board, a time-frequency processing board, a navigation simulation board, a key display board, a power module, and a transmitting antenna; The key display board is used to receive user input instructions and send them to the integrated control board, and is also used to receive the status information monitored by the integrated control board and display it; The time-frequency processing board is used to receive the time acquisition instruction input by the user sent by the integrated control board, obtain the external standard time source signal through the integrated control board, process it to obtain the local 1PPS+ToD signal, provide the local 1PPS signal to the chip atomic clock for clock taming to obtain the reference frequency, perform time conversion on the local ToD signal to obtain the Beidou time, and provide the reference frequency and the Beidou time to the navigation simulation board through the integrated control board; The navigation simulation board is used to receive the Beidou time and the reference frequency sent by the integrated control board; based on the set signal generation parameters, the Beidou time, and the reference frequency, perform navigation message encoding and modulation to generate an analog Beidou navigation signal, and send it to the transmitting antenna; The transmitting antenna is used to transmit the analog Beidou navigation signal to the ground Beidou receiver device; The power module is used to perform power conversion and supply power to the battery; The integrated control board is used to be respectively connected to the key display board, the time-frequency processing board, the navigation simulation board, and the power module for data interaction and power consumption management; The time-frequency processing board includes a 1PPS signal processing module and a B-code decoding module, and also includes a chip atomic clock; the external standard time source signal includes a 1PPS+ToD signal and a B-code signal; the 1PPS signal processing module receives the 1PPS+ToD signal, and uses a low-power MCU chip and a high-precision 1PPS phase discriminator chip to implement local 1PPS signal processing to obtain the first local 1PPS+ToD signal; the B-code decoding module receives the B-code signal and performs decoding processing to obtain the second local 1PPS+ToD signal; provide the first local 1PPS signal or the second local 1PPS signal to the chip atomic clock for clock taming to obtain the reference frequency; the 1PPS signal processing module performs time conversion on the first local ToD signal and the second local ToD signal to obtain the Beidou time, and provides the Beidou time and the reference frequency for the navigation simulation board through the integrated control board.

2. The regional wireless high-precision timekeeping and time dissemination system according to claim 1, wherein The navigation simulation board includes a signal control unit, a navigation signal modulation and simulation unit, a clock source circuit, and a radio frequency power amplifier unit; the signal control unit performs navigation message encoding based on the set signal generation parameters and the reference frequency output by the received time-frequency processing board; The clock source circuit generates a modulation reference frequency for the navigation signal modulation and simulation unit; The navigation signal modulation and simulation unit modulates the encoded navigation message to generate an analog Beidou navigation signal; the radio frequency power amplifier circuit processes the analog Beidou navigation signal and sends it to the transmitting antenna.

3. The regional wireless high-precision timekeeping and time dissemination system according to claim 1, wherein The integrated control board includes a time-frequency control unit, a navigation control unit, a human-machine interaction unit, and a power consumption control unit; the time-frequency control unit is connected to the time-frequency processing board for data interaction; the navigation control unit is connected to the navigation simulation board for data interaction; the human-machine interaction unit is connected to the button display board for data interaction; the power consumption control unit is connected to the human-machine interaction unit, and when receiving a standby instruction input by the user or detecting no operation within a preset time, performs power consumption management on the power output by the power supply module.

4. The regional wireless high-precision timekeeping and time dissemination system according to claim 3, characterized in that When receiving a standby instruction input by the user or detecting no operation within a preset time, perform power consumption management on the power output by the power supply module, specifically including: When the integrated control board receives a standby instruction input by the user or the integrated control board detects no operation within a preset time, the power consumption control unit will disconnect all the power of the navigation simulation board, part of the power of the time-frequency processing board, part of the power of the integrated control board, and the power of the liquid crystal display screen.

5. The regional wireless high-precision timekeeping and time dissemination system according to claim 1, characterized in that, The transmitting antenna uses a microstrip antenna.

6. The regional wireless high-precision timekeeping and time dissemination system according to claim 1, characterized in that It further includes: An aviation plug-in; the aviation plug-in is respectively connected to the integrated control board and an external standard time source device, the external standard time source device is used to provide an external standard time source signal, and the integrated control board sends the external standard time source signal to the time-frequency processing board.

7. The regional wireless high-precision timekeeping and time dissemination system according to claim 1, characterized in that, The power supply module uses a DC-DC conversion chip.

8. A regional wireless high-precision timekeeping and time dissemination method, characterized in that, Based on the timekeeping and time service system according to any one of claims 1 to 7, the method includes: A time synchronization and timekeeping maintenance step, the time-frequency processing board tames the local chip atomic clock by tracking the external standard time source signal, and after disconnecting the external time source signal, the system will enter the atomic clock start timekeeping stage and continuously output a high-precision clock signal; the integrated control board monitors the working states of the time-frequency processing board and the atomic clock in real time; A navigation signal generation and modulation output step, the integrated control board sets the signal generation parameters of the navigation simulation board according to the user's instructions; the navigation simulation board encodes and modulates the navigation message based on these parameters and in combination with the timekeeping signal to generate an analog Beidou navigation signal, which is output to the transmitting antenna after amplification and filtering processing; A signal transmitting and state monitoring step, the transmitting antenna transmits the navigation signal according to the set parameters; the integrated control board collects the working state data of each part in the timekeeping and time service system in real time and displays it to the user through the button display board; A standby timekeeping step, after detecting no operation within a preset time or receiving a user standby instruction, the integrated control board performs low-power management, keeps the chip atomic clock and related circuits running, cuts off the power of the remaining circuits, and the system enters a high-precision timekeeping state, waiting to be woken up for the next use.

9. The regional wireless high-precision timekeeping and time service method according to claim 8, characterized in that, Before the time synchronization and timekeeping maintenance step, there is also a startup initialization step, as follows: After the system is powered on, the integrated control board first performs a system self-check, detects the connection status and working parameters of each part of the hardware, and at the same time initializes the internal software program and configures the initial working modes of each part; the time-frequency processing board is in a free-running state, waiting for the user to perform a time acquisition operation, the navigation simulation board loads a pre-stored navigation signal configuration file, and the transmitting antenna enters a state of waiting to transmit.

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