CN215581727U - Short wave timing signal and information receiving device - Google Patents
Short wave timing signal and information receiving device Download PDFInfo
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- CN215581727U CN215581727U CN202121682695.8U CN202121682695U CN215581727U CN 215581727 U CN215581727 U CN 215581727U CN 202121682695 U CN202121682695 U CN 202121682695U CN 215581727 U CN215581727 U CN 215581727U
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Abstract
The invention provides a short-wave timing signal and information receiving device which comprises a frequency selection module, an RTC module, a main control module, a clock module, a signal processing module, a monitoring module and a communication module, wherein the main control module judges a frequency point of a receivable signal at the current position according to position information input by a user and sends a frequency selection instruction to the frequency selection module, so that the signal receiving time can be effectively shortened. The frequency selection module receives short wave time service signals input by the antenna, selects one of signals of 2.5MHz, 5.0MHz, 10.0MHz and 15.0MHz under the control of a frequency selection instruction of the main control module to carry out amplification, filtering and frequency mixing processing, and sends processed analog intermediate frequency signals to the signal processing module to be converted into digital intermediate frequency signals. The invention can effectively shorten the signal searching and capturing time, demodulate and output time information, realize the automatic calibration of local time and solve the problem that a user needs to manually input the time information.
Description
Technical Field
The invention relates to the field of short wave timing, in particular to a short wave timing signal and information receiving device for receiving BPM (wideband modulation) timing signals and time code information with frequencies of 2.5MHz, 5MHz, 10MHz and 15 MHz.
Background
The BPM short wave time service station of the national time service center broadcasts standard time and standard frequency signals 24 hours a day at 4 frequencies of 2.5MHz, 5.0MHz, 10.0MHz and 15.0MHz, and the timing precision of a user is in millisecond level. In order to further improve the service capability of the BPM short-wave time service broadcasting system in China, the BPM time service station adds time code service to a short-wave time service program, and a user can obtain standard time code information through a short-wave time code receiver, so that the clock surface is calibrated and the automation of equipment operation is realized.
Most of the existing short-wave terminal equipment are short-wave communication equipment, and few short-wave timing terminal equipment mainly demodulate short-wave time signals and do not have the capacity of demodulating short-wave time information. The disclosed technical scheme of 'time service and broadcast of BPM short wave time code' specifies the design scheme, the format and the broadcast period of the BPM time code, wherein the mentioned BPM time code demodulation part exemplifies the basic decoding method of the time code information, mainly relates to how to resolve a time frame into time information, and does not relate to the specific implementation. The disclosed BPM short-wave time code receiving technology research of DSP provides a technical method for receiving short-wave time code information, and the method does not relate to the influence of positions on signal delay and the specific hardware realization. Therefore, it is necessary to provide a receiving device with the capability of demodulating BPM short-wave time signals and short-wave time codes at a relatively low cost.
Disclosure of Invention
In order to overcome the defects of the prior art, the invention provides a short-wave timing signal and information receiving device, which receives and demodulates 2.5MHz, 5.0MHz, 10.0MHz and 15.0MHz signals transmitted by a national time service center of China academy of sciences, demodulates and outputs UTC (coordinated universal time), UT1 (universal time), 1PPS (second signal) and 1PPM (sub-signal) signals, can demodulate time code information attached to 5MHz frequency signals, stores and maintains time information through RTC (real-time clock), and solves the problem that a short-wave time service receiver needs to receive external time information to realize autonomous timing.
The technical scheme adopted by the invention for solving the technical problems is as follows: a short-wave timing signal and information receiving device comprises a frequency selection module, an RTC module, a master control module, a clock module, a signal processing module, a monitoring module and a communication module.
The frequency selection module receives a parameter control instruction from the main control module, and filters and outputs signals of 2.5MHz, 5MHz, 10MHz and 15MHz to the signal processing module;
the main control module receives the digital intermediate frequency signal from the signal processing module, acquires a baseband voice signal and sends the baseband voice signal to the monitoring module; the main control module receives the excitation of the clock module and sends the identified 1PPS signal or 1PPM signal to the communication module; the main control module decodes the baseband signal, acquires the correction values of year, month, day, time, minute and second, UT1 and leap second forecast information and transmits the information to the RTC module and the communication module; the main control module receives the position information from the communication module and sends a frequency selection instruction to the frequency selection module;
the signal processing module converts the analog intermediate frequency signal from the frequency selection module into a 16-bit digital intermediate frequency signal and outputs the 16-bit digital intermediate frequency signal to the main control module; meanwhile, the 16-bit digital monitoring signal output by the main control module is converted into an analog monitoring signal and sent to the monitoring module;
the monitoring module outputs the analog monitoring signal through a loudspeaker, and displays the time information output by the main control module through a liquid crystal display;
the clock module provides a reference clock for the frequency selection module, the main control module and the signal processing module;
the RTC module receives the time information sent by the main control module and is used for storing and keeping the time information;
the communication module receives the 1PPS signal, the 1PPM signal and the time information output by the main control module and outputs the signals to the outside, and simultaneously receives the control information and the position information input from the outside and sends the information to the main control module.
The parameter control instruction from the main control module comprises tuning frequency, frequency search, received signal strength threshold and output signal amplitude.
The RTC module receives the time information sent by the main control module, keeps the information of second, minute, time, week, day, month and year and times, so that the receiving device cannot lose the time information due to power failure; when the device is powered on again, the master control module reads the second, minute, hour, week, day, month and year information of the RTC module.
The main control module receives the digital intermediate frequency signal from the signal processing module, filters and demodulates the digital intermediate frequency signal, acquires a baseband voice signal and sends the baseband voice signal to the monitoring module; the main control module carries out relevant processing on the baseband voice signal under the excitation of the clock module, identifies a 1PPS signal or a 1PPM signal, calculates propagation delay according to the received position information from the communication module, carries out delay adjustment on the identified 1PPS signal or the 1PPM signal, and sends the signal to the communication module; after recognizing the 1PPS or 1PPM signal, the main control module decodes the baseband signal, acquires the correction values of year, month, day, hour, minute, second, UT1 and leap second forecast information, and sends the information to the RTC module and the communication module; the main control module receives the position information from the communication module, judges the frequency of the receivable signals at the current position according to the signal position lookup table, and sends a frequency selection instruction to the frequency selection module.
The signal processing module takes a clock signal sent by the clock module as a reference, and a data receiving part of the signal processing module converts an analog intermediate frequency signal from the frequency selection module into a 16-bit digital intermediate frequency signal at the rising edge of the clock signal at a sampling rate of 32kHz and outputs the 16-bit digital intermediate frequency signal to the main control module; meanwhile, a data sending part of the signal processing module receives the 16-bit digital monitoring signal output by the main control module at the falling edge of the clock signal, converts the 16-bit digital monitoring signal into an analog monitoring signal at a sampling rate of 32kHz and sends the analog monitoring signal to the monitoring module.
The frequency selection module comprises a low-noise amplifier, a tuning circuit, an automatic gain control, a mixer, a digital oscillator and an automatic frequency control, wherein the low-noise amplifier carries out filtering amplification and interference suppression on a weak signal sensed by an antenna so as to reduce system noise; the tuning circuit consists of four tuning filters, the center frequencies of the tuning filters are respectively 2.5MHz, 5MHz, 10MHz and 15MHz, and the signals are tracked and frequency-selected; the automatic gain control adopts closed-loop delay AGC to realize automatic adjustment of the gain of the amplification system; the mixer adopts a primary down-conversion structure, mixes the signal output by the automatic gain control with the carrier frequency signal output by the digital oscillator, outputs an analog intermediate frequency signal and sends the analog intermediate frequency signal to the signal processing module; the digital oscillator is internally provided with a low-dropout voltage regulating circuit, and the output frequency of the digital oscillator is controlled and calibrated by automatic frequency.
The invention has the beneficial effects that: the device is internally provided with a signal position lookup table, and can pre-judge receivable signal frequency points according to position information input by a user based on the table, so that the time for searching and capturing signals can be effectively shortened. Meanwhile, the signal position lookup table contains preset time delay correction information, and a user can perform time delay correction on the timing signal through inputting the position information. In addition, the device can demodulate and output time information in a 5MHz working mode, realize automatic calibration of local time, and solve the problem that a user needs to manually input time information.
Drawings
Fig. 1 is a block diagram of a composition structure of an embodiment of the present invention.
Fig. 2 is a block diagram of the structure of the frequency selection module 1 in fig. 1.
Detailed Description
The present invention will be further described with reference to the following drawings and examples, which include, but are not limited to, the following examples.
The invention comprises a frequency selection module, an RTC module, a main control module, a clock module, a signal processing module, a monitoring module and a communication module, wherein the main control module is used as a core module to generate interaction and coordinate with other modules, and the technical scheme is realized as follows:
1) the main control module is internally stored with a signal position lookup table, can judge the frequency point of the current position capable of receiving signals according to the position information input by the user, and sends a frequency selection instruction to the frequency selection module, thereby effectively shortening the signal receiving time. The frequency selection module receives a short wave time service signal input by an antenna, selects one of signals of 2.5MHz, 5.0MHz, 10.0MHz and 15.0MHz under the control of a frequency selection instruction of the main control module to carry out amplification, filtering and frequency mixing processing, and sends a processed analog intermediate frequency signal to the signal processing module to be converted into a digital intermediate frequency signal;
2) the main control module is used as a core part, receives the digital intermediate frequency signal sent by the signal processing module, demodulates the digital intermediate frequency signal to obtain a timing signal, and performs time delay correction on the timing signal based on the signal position lookup table according to position information input by a user. Time information is loaded in a 5MHz signal transmitted by a BPM (national time service center) time service station, and if the device works at 5MHz and the signal is effective, the time information is demodulated from the 5MHz signal and is used for calibrating local time. Meanwhile, the main control module sends the demodulated 1PPS and 1PPM signals to the monitoring module as voice monitoring signals for monitoring; sending the state monitoring information obtained in the demodulation process to a monitoring module for displaying;
3) the monitoring module receives a voice monitoring signal and state monitoring information sent by the main control module, and the voice monitoring signal is converted into an analog signal and output through a loudspeaker for monitoring the current signal state; the state monitoring information is displayed through the display screen, so that a user can directly observe the current working frequency, working state, field intensity and signal-to-noise ratio information of the device conveniently.
The structural block diagram of the embodiment of the invention is shown in fig. 1, and the device is formed by connecting a frequency selection module 1, an RTC module 2, a main control module 3, a clock module 4, a signal processing module 5, a monitoring module 6 and a communication module 7.
The frequency selection module 1 is connected with an external antenna, the main control module 3 and the signal processing module 5, the frequency selection module 1 receives tuning frequency, frequency search, received signal strength threshold and output signal amplitude parameter control instructions from the main control module 3, and under the control of the main control module 3, signals of 2.5MHz, 5MHz, 10MHz and 15MHz are filtered and output to the signal processing module 5.
The RTC module 2 is connected with the main control module 3, and the RTC module 2 receives the time information sent by the main control module 3 and is used for storing and keeping the time information. When the short-wave time service signal receiving device is powered off, the RTC module 2 keeps information of second, minute, hour, week, day, month, year and the like and performs timing, so that the receiving device cannot lose time information due to power failure; when the device is powered on again, the main control module 3 reads the information of the RTC module 2 such as second, minute, time, week, day, month, year and the like, so that the device can rapidly enter a time service state after being powered on again.
The main control module 3 is respectively connected with the frequency selection module 1, the RTC module 2, the clock module 4, the signal processing module 5, the monitoring module 6 and the communication module 7, and is a core part of the short-wave timing information and signal receiving device. The main control module 3 receives the digital intermediate frequency signal from the signal processing module 5, and filters and demodulates the digital intermediate frequency signal to obtain a baseband voice signal, and sends the baseband voice signal to the monitoring module 6. The main control module 3 performs relevant processing on the baseband voice signal under the excitation of the clock module 4, and identifies a 1PPS signal or a 1PPM signal. Then, the propagation delay is calculated according to the received position information from the communication module 7, the identified 1PPS signal or 1PPM signal is subjected to delay adjustment, and the signal is sent to the communication module 7. After recognizing the 1PPS or 1PPM signal, the main control module 3 decodes the baseband signal, acquires information such as year, month, day, hour, minute, second, UT1 correction value and leap second forecast, and sends the information to the RTC module 2 and the communication module 7. The main control module 3 receives the position information from the communication module 7, judges the frequency of the receivable signals at the current position according to the signal position lookup table, and sends a frequency selection instruction to the frequency selection module 1.
The clock module 4 is connected with the frequency selection module 1, the main control module 3 and the signal processing module 5, and can provide multi-output clock distribution. The clock module 4 provides a reference clock of 32.768kHz for the frequency selection module 1, a reference clock of 32MHz for the main control module 3, and a reference frequency of 12.288MHz for the signal processing module 5. The clock module 4 provides the device with clock signals of the same source, and aims to eliminate phase differences among modules and keep the phases of the modules consistent.
The signal processing module 5 is connected with the frequency selection module 1, the main control module 3, the clock module 4 and the monitoring module 6, the signal processing module 5 takes a clock signal sent by the clock module 4 as a reference, and a data receiving part of the signal processing module converts an analog intermediate frequency signal from the frequency selection module 1 into a 16-bit digital intermediate frequency signal at a sampling rate of 32kHz on the rising edge of the clock signal and outputs the 16-bit digital intermediate frequency signal to the main control module 3. Meanwhile, the data sending part of the signal processing module 5 receives the 16-bit digital monitoring signal output by the main control module 3 at the falling edge of the clock signal, converts the 16-bit digital monitoring signal into an analog monitoring signal at a sampling rate of 32kHz and sends the analog monitoring signal to the monitoring module 6.
The monitoring module 6 is connected with the main control module 3 and the signal processing module 5 and mainly comprises a voice output part and a display part. The voice output part receives the voice monitoring signal output by the signal processing module 5, outputs the voice monitoring signal through a loudspeaker, and a user can monitor the quality of a local BPM electric wave signal at the current moment through the loudspeaker; the display part receives the time information, the working state and other information from the main control module 3 and displays the information through the liquid crystal display screen.
The communication module 7 is connected with the main control module 3, receives the 1PPS signal, the 1PPM signal and the time information output by the main control module 3, converts the time information into a serial signal of RS232 level and outputs the serial signal. Meanwhile, control information and position information input from the outside are received through the serial port and sent to the main control module 3.
The frequency selection module 1 shown in fig. 2 of the present invention is composed of a low noise amplifier 101, a tuning circuit 102, an automatic gain control 103, a mixer 104, a digital oscillator 105 and an automatic frequency control 106.
The low-noise amplifier 101 performs filtering amplification and interference suppression on a weak signal sensed by the antenna, and reduces system noise. The noise coefficient of the low-noise amplifier 101 is less than 2, the gain is 20dB, and the receiving sensitivity is 20 uV. 101 has the function of amplitude limiting protection to prevent the large signal with the peak value exceeding 1V from entering, and the filtered and amplified signal is sent to the tuning circuit 102.
The tuning circuit 102 is composed of four tuning filters for filtering out-of-band interference and noise. The center frequencies of the tuning filters are 2.5MHz, 5MHz, 10MHz, and 15MHz, respectively, the signals are tracked and frequency-selected, and the frequency-selected signals are sent to the band-pass filter 103.
The automatic gain control 103 adopts closed-loop delay type AGC, the dynamic range is 85dB, and the stepping amount is 2 dB. The automatic gain control 103 is close to the front end of the intermediate frequency and is used for controlling the amplification factor and the bandwidth, realizing the automatic adjustment of the gain of the amplification system, keeping the amplitude of the output signal to change in a small range and improving the signal-to-noise ratio. The automatic gain control 103 outputs a signal to the mixer 104.
The mixer 104 is connected to the agc 103 and the digital oscillator 105, and the mixer 104 adopts a one-time down-conversion structure, mixes the signal output by the agc 103 with the carrier frequency signal output by the digital oscillator 105, and outputs an analog if signal to the signal processing module 5.
The digital oscillator 105 is provided with a low dropout voltage regulation circuit, and the output frequency of the digital oscillator 105 is calibrated by an automatic frequency control 106. The frequency signal generated by the digital oscillator 105 is sent to the mixer 104, and the local carrier frequency output by the digital oscillator 105 is kept stable under the feedback control of the automatic frequency control 106.
The automatic frequency control 106 consists of a mixing and difference amplification section, which limits the local oscillator signal frequency drift by adjusting the center frequency of the intermediate frequency. The afc 106 receives the reference clock signal from the clock module 4 and the frequency signal generated by the digital oscillator 105, detects a frequency error between the reference clock signal and the digital oscillator 105 by mixing, amplifies the error signal by a difference frequency, and converts the amplified error signal into a voltage error signal to control the digital oscillator 105.
Claims (6)
1. A short-wave timing signal and information receiving device comprises a frequency selection module, an RTC module, a main control module, a clock module, a signal processing module, a monitoring module and a communication module,
the frequency selection module receives a parameter control instruction from the main control module, and filters and outputs signals of 2.5MHz, 5MHz, 10MHz and 15MHz to the signal processing module;
the main control module receives the digital intermediate frequency signal from the signal processing module, acquires a baseband voice signal and sends the baseband voice signal to the monitoring module; the main control module receives the excitation of the clock module and sends the identified 1PPS signal or 1PPM signal to the communication module; the main control module decodes the baseband signal, acquires the correction values of year, month, day, time, minute and second, UT1 and leap second forecast information and transmits the information to the RTC module and the communication module; the main control module receives the position information from the communication module and sends a frequency selection instruction to the frequency selection module;
the signal processing module converts the analog intermediate frequency signal from the frequency selection module into a 16-bit digital intermediate frequency signal and outputs the 16-bit digital intermediate frequency signal to the main control module; meanwhile, the 16-bit digital monitoring signal output by the main control module is converted into an analog monitoring signal and sent to the monitoring module;
the monitoring module outputs the analog monitoring signal through a loudspeaker, and displays the time information output by the main control module through a liquid crystal display;
the clock module provides a reference clock for the frequency selection module, the main control module and the signal processing module;
the RTC module receives the time information sent by the main control module and is used for storing and keeping the time information;
the communication module receives the 1PPS signal, the 1PPM signal and the time information output by the main control module and outputs the signals to the outside, and simultaneously receives the control information and the position information input from the outside and sends the information to the main control module.
2. The short wave timing signal and information receiving apparatus of claim 1 wherein the parameter control commands from the master control module include tuning frequency, frequency search, received signal strength threshold, and output signal amplitude.
3. The short-wave timing signal and information receiving device of claim 1, wherein the RTC module receives the time information sent by the main control module, and keeps and times the second, minute, hour, week, day, month and year information, so that the receiving device does not lose the time information due to power failure; when the device is powered on again, the master control module reads the second, minute, hour, week, day, month and year information of the RTC module.
4. The short wave timing signal and information receiving apparatus of claim 1, wherein the main control module receives the digital intermediate frequency signal from the signal processing module, filters and demodulates the digital intermediate frequency signal, obtains a baseband voice signal, and sends the baseband voice signal to the monitoring module; the main control module carries out relevant processing on the baseband voice signal under the excitation of the clock module, identifies a 1PPS signal or a 1PPM signal, calculates propagation delay according to the received position information from the communication module, carries out delay adjustment on the identified 1PPS signal or the 1PPM signal, and sends the signal to the communication module; after recognizing the 1PPS or 1PPM signal, the main control module decodes the baseband signal, acquires the correction values of year, month, day, hour, minute, second, UT1 and leap second forecast information, and sends the information to the RTC module and the communication module; the main control module receives the position information from the communication module, judges the frequency of the receivable signals at the current position according to the signal position lookup table, and sends a frequency selection instruction to the frequency selection module.
5. The short-wave timing signal and information receiving device according to claim 1, wherein the signal processing module is based on the clock signal transmitted from the clock module, and the data receiving portion converts the analog intermediate frequency signal from the frequency selection module into a 16-bit digital intermediate frequency signal at a sampling rate of 32kHz at a rising edge of the clock signal and outputs the signal to the main control module; meanwhile, a data sending part of the signal processing module receives the 16-bit digital monitoring signal output by the main control module at the falling edge of the clock signal, converts the 16-bit digital monitoring signal into an analog monitoring signal at a sampling rate of 32kHz and sends the analog monitoring signal to the monitoring module.
6. The short wave timing signal and information receiving apparatus of claim 1, wherein the frequency selective module comprises a low noise amplifier, a tuning circuit, an automatic gain control, a mixer, a digital oscillator and an automatic frequency control, the low noise amplifier performs filtering amplification, interference suppression and system noise reduction on a weak signal sensed by the antenna; the tuning circuit consists of four tuning filters, the center frequencies of the tuning filters are respectively 2.5MHz, 5MHz, 10MHz and 15MHz, and the signals are tracked and frequency-selected; the automatic gain control adopts closed-loop delay AGC to realize automatic adjustment of the gain of the amplification system; the mixer adopts a primary down-conversion structure, mixes the signal output by the automatic gain control with the carrier frequency signal output by the digital oscillator, outputs an analog intermediate frequency signal and sends the analog intermediate frequency signal to the signal processing module; the digital oscillator is internally provided with a low-dropout voltage regulating circuit, and the output frequency of the digital oscillator is controlled and calibrated by automatic frequency.
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN116633327A (en) * | 2023-07-20 | 2023-08-22 | 泉州艾奇科技有限公司 | Clock circuit, electronic equipment and chip based on time service pulse timing |
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN116633327A (en) * | 2023-07-20 | 2023-08-22 | 泉州艾奇科技有限公司 | Clock circuit, electronic equipment and chip based on time service pulse timing |
| CN116633327B (en) * | 2023-07-20 | 2023-10-10 | 泉州艾奇科技有限公司 | Clock circuit, electronic equipment and chip based on time service pulse timing |
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