CN111538228B - Low-frequency time code timing signal simulator - Google Patents
Low-frequency time code timing signal simulator Download PDFInfo
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- CN111538228B CN111538228B CN202010284147.3A CN202010284147A CN111538228B CN 111538228 B CN111538228 B CN 111538228B CN 202010284147 A CN202010284147 A CN 202010284147A CN 111538228 B CN111538228 B CN 111538228B
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- G—PHYSICS
- G04—HOROLOGY
- G04R—RADIO-CONTROLLED TIME-PIECES
- G04R20/00—Setting the time according to the time information carried or implied by the radio signal
- G04R20/02—Setting the time according to the time information carried or implied by the radio signal the radio signal being sent by a satellite, e.g. GPS
- G04R20/04—Tuning or receiving; Circuits therefor
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- G—PHYSICS
- G04—HOROLOGY
- G04R—RADIO-CONTROLLED TIME-PIECES
- G04R20/00—Setting the time according to the time information carried or implied by the radio signal
- G04R20/02—Setting the time according to the time information carried or implied by the radio signal the radio signal being sent by a satellite, e.g. GPS
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Abstract
The invention provides a low-frequency time code timing signal simulator.A simulator control unit controls the selection of frequency points, the control of amplitude, the presence or absence and the amplitude of interference and noise according to external input; the time frequency generating unit outputs a 10MHz frequency signal and a 1PPS timing signal to the signal generating and converting unit; the signal generating and converting unit simulates to generate a multi-frequency point low-frequency time code time service signal, adjusts the phase consistency of the output signal, and outputs a ground wave signal, a sky wave signal, an interference signal and a random noise four-way signal to the signal synthesis output unit; the signal synthesis output unit converts the four paths of signals into analog signals through a digital-to-analog converter, and outputs low-frequency time code timing signals after amplitude adjustment. The invention has high transmission control precision, can flexibly simulate signals in reality, adjust the amplitude, noise and interference of the signals, and can output any two paths of low-frequency time code signals with higher phase consistency.
Description
Technical Field
The invention belongs to the technical field of signal and information processing, and relates to a signal simulator which is used for providing analog signals for development and time delay calibration of a low-frequency time code timing receiver.
Background
The low-frequency time code technology is a low-frequency low-speed time service mode which is always encouraged and supported by the International Telecommunication Union (ITU); the low-frequency radio wave is mainly propagated by earth waves and sky waves, is propagated in various modes between the ground and an ionized layer, has small loss, high phase stability and wide coverage range (the sky wave coverage radius can reach more than 2000 kilometers), and is very suitable for bearing time code information.
The low-frequency time code technology makes use of the characteristics of stable low-frequency radio wave transmission, wide coverage range, strong penetration capacity and the like, and makes great progress in the fields of radio-controlled clocks and watches and civil engineering. The major countries in the world all have independent low-frequency time code timing systems, and the call sign of the American low-frequency time code timing station is WWVB (carrier wave is 60 kHz); russia has two low-frequency time code time service station calls of RTZ (carrier wave is 50kHz) and RBU (carrier wave is 66.66kHz) due to large territorial area; the call sign of the English low-frequency time code service station is MSF (the carrier wave is 60 kHz); the call sign of the German low-frequency time code service station is DCF77 (the carrier wave is 77.5 kHz); the Japanese has two low-frequency time code time service station call signs of JJY40 (carrier wave is 40kHz) and JJY60 (carrier wave is 60 kHz); the low-frequency time code time service station call sign in China is BPC (carrier frequency is 68.5kHz), and is located in Shangqiu city in Henan province.
Traditional low frequency time code time service signal analog source adopts analogue means to build, it is low to send out and broadcast control accuracy, can not adjust the output amplitude of signal, can not simulate noise and interference in the reality, can not output multi-frequency point, can not carry out the phase uniformity to the output signal of multi-frequency point and keep, only can simulate the signal of an output low frequency time code time service platform, for example BPC special signal analog source, can only output 68.5kHz BPC time code, and send out and broadcast control accuracy lower, special analog source of this type can not satisfy the demand in scientific research and market.
Disclosure of Invention
In order to overcome the defects of the prior art, the invention provides a low-frequency time code timing signal simulator which is controlled by a digital circuit, has high transmission control precision, can flexibly simulate signals in reality, adjust the amplitude, noise and interference of the signals, can provide excitation signals for the development of low-frequency time code receivers of various models, simulate the signals of BPC, WWVB in the United states, JJY40 and JJY60 low-frequency time code timing tables in Japan, can output any two paths of low-frequency time code signals in high phase consistency, and can provide services for the debugging, performance evaluation and equipment maintenance of a low-frequency time code timing system.
The technical scheme adopted by the invention for solving the technical problems is as follows: a low-frequency time code time signal simulator comprises a simulator control unit, a time frequency generation unit, a signal generation and conversion unit and a signal synthesis output unit.
The simulator control unit controls the selection of frequency points, the control of amplitude, the presence or absence and the amplitude of interference and noise according to external input; the time frequency generating unit selects frequency and time source according to the time frequency signal provided by the simulator control unit, generates a working clock required by FPGA working, and outputs a 10MHz frequency signal and a 1PPS timing signal to the signal generating and converting unit; the signal generating and converting unit simulates to generate a multi-frequency point low-frequency time code time service signal, adjusts the phase consistency of the output signal, and outputs a ground wave signal, a sky wave signal, an interference signal and a random noise four-way signal to the signal synthesis output unit; the signal synthesis output unit converts the four paths of signals into analog signals through a digital-to-analog converter, adjusts the amplitude of ground wave signals, sky wave signals, interference signals and random noise according to the parameters output by the simulator control unit, and generates and outputs low-frequency time code timing signals.
The simulator control unit comprises a keyboard, a liquid crystal display screen, a GNSS receiver and a simulation source central processing unit; the central processing unit receives configuration information input by the keyboard and transmits characteristic parameters of signals being output to the liquid crystal display screen for display, the GNSS receiver is a GPS or Beidou receiver, and the central processing unit transmits time code information and position information demodulated by the GNSS receiver to the time frequency generation unit and the signal generation and conversion unit.
The time frequency generating unit comprises a constant temperature crystal oscillator, a frequency selector, a time signal selector and a clock management chip; the 10MHz signal of external input and 10MHz signal that the constant temperature crystal oscillator that the simulator is from taking produces output to the frequency selector respectively, the frequency selector chooses two 10MHz frequency signals, and the internal 10MHz signal that the preferred choice simulator is from, 10MHz signal enters the clock management chip and produces the working clock, the frequency of the working clock can be divided to the low frequency time code carrier frequency by the integer; the GNSS receiver outputs the demodulated and output 1PPS timing signal and the time code information to a time signal selector, the time signal selector judges the 1PPS signal input by the GNSS receiver and the 1PPS timing signal generated by internal frequency division, the 1PPS internal input is preferentially selected, and then the 1PPS timing signal is output; and in the same way, selecting the time code information, and preferentially selecting the internal time code information.
The signal generating and converting unit comprises a low-frequency time code coding modulation module, a low-frequency time code signal format parameter configuration module, a delay module, a random noise module and an interference module; the low-frequency time code signal format parameter configuration module selectively outputs a Chinese BPC time code, a Japanese JJY time code or a U.S. WWVB time code according to the signal parameters, correspondingly modulates and codes time code information through the low-frequency time code modulation module and outputs a ground wave signal, and the delay module delays the ground wave signal according to the input sky wave parameters to generate a sky wave signal; the random noise module generates and outputs a noise signal according to the input noise parameter; the interference module generates an interference signal according to the input interference parameter.
The signal synthesis output unit comprises a digital-to-analog conversion module, an amplitude regulation module, a signal synthesis module and a filter module; the digital-to-analog conversion module converts the ground wave signal, the sky wave signal, the noise signal and the interference signal into analog signals and outputs the analog signals to the amplitude regulation module; the amplitude adjusting module performs amplitude adjusting control according to the input signal amplitude adjusting parameters and then outputs the signals to the signal synthesizing module; and finally, outputting a low-frequency time code time service signal after filtering.
The invention has the beneficial effects that: due to the adoption of
(1) The invention can simulate various low-frequency time code signals at home and abroad, including time service signals of a Chinese BPC time service broadcasting station, a U.S. WWVB time service broadcasting station, Japanese JJY40 and JJY60 broadcasting stations;
(2) the invention can adjust the earth wave signal amplitude, sky wave signal amplitude, noise amplitude and interference amplitude of the low-frequency time code according to the requirement so as to adapt to different application occasions;
(3) the low-frequency time code signal output by the invention has high phase consistency and can be applied to various purposes such as time delay calibration of a low-frequency time code receiver, noise resistance and anti-interference capability test of the receiver and the like;
(4) the GNSS timing receiver is arranged in the invention, so that a time service signal for modulating the low-frequency time code in real time can be provided, and the time delay calibration of the low-frequency time code receiver by a user is facilitated; meanwhile, the built-in fixed time information is provided, and a user can select the fixed time information according to different use environments;
(5) the frequency and time signal automatic selector provided by the invention can be switched according to requirements, and is convenient to use.
Drawings
FIG. 1 is a block diagram of the overall architecture of the present invention;
FIG. 2 is a block diagram of the simulator control unit architecture of the present invention;
FIG. 3 is a block diagram of the time frequency generation unit according to the present invention;
FIG. 4 is a block diagram of the signal generating and converting unit according to the present invention;
fig. 5 is a block diagram of the signal synthesis output unit according to the present invention.
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 provides a low-frequency time code timing signal simulator which is complete in function, simple in operation and extensible, aims to meet the requirements of construction and development of a low-frequency time code timing system and research and development of a low-frequency time code timing receiver in China, can simulate signals of BPC, WWVB in the United states, JJY40 and JJY60 low-frequency time code timing stations in China anywhere, and gives consideration to the real-time performance of timing signals so as to meet the requirements of construction and maintenance of the low-frequency time code timing system, development and debugging of the low-frequency time code timing receiver, time delay marking and the like.
The invention provides a low-frequency time code time service signal simulator, which comprises a simulator control unit, a time frequency generation unit, a signal generation and conversion unit and a signal synthesis output unit, wherein the simulator control unit is used for controlling the time frequency generation unit to generate a low-frequency time code time service signal;
the simulator control unit configures the simulator according to the input of the keyboard, including the selection of frequency points, the control of amplitude, the control of the presence or absence of interference and noise and the control of amplitude; and the relevant parameters are displayed through a liquid crystal display screen, and the time code information output by the GNSS receiver is output to the low-frequency time code signal generating and converting unit. The time frequency generating unit selects frequency and time source according to the time frequency parameter input by the simulator control unit, generates a working clock required by FPGA working, and outputs a 10MHz frequency signal and a 1PPS timing signal to the signal generating and converting unit; the signal generating and converting unit simulates to generate a multi-frequency point low-frequency time code time service signal, adjusts the phase consistency of an output signal, and outputs a ground wave signal, a sky wave signal, an interference signal and random noise, and four paths of signals to the signal synthesis output unit; the signal synthesis output unit converts the four paths of signals into analog signals through a digital-to-analog converter, adjusts the amplitude of ground wave signals, sky wave signals, interference signals and random noise according to the parameters output by the simulator control unit, and generates and outputs low-frequency time code timing signals.
The simulator control unit comprises a keyboard, a liquid crystal display screen, a GNSS receiver and a simulation source central processing unit; the central processing unit receives configuration information input by the keyboard and transmits characteristic parameters of signals being output to the liquid crystal display screen for display, the GNSS receiver is a GPS or Beidou receiver, and the central processing unit transmits time code information and position information demodulated by the GNSS receiver to the time frequency generation unit and the signal generation and conversion unit.
The time frequency generation unit mainly provides an operating clock and a timing signal for the whole simulator. The system comprises a constant temperature crystal oscillator, a frequency selector, a time signal selector and a clock management chip; the 10MHz signal of external input and 10MHz signal that the constant temperature crystal oscillator that the simulator is from taking produces output to the frequency selector respectively, the frequency selector chooses two 10MHz frequency signals, and the internal 10MHz signal that the preferred choice simulator is from taking, 10MHz signal enters the clock and manages the working clock that the chip generating circuit of the clock needs of working, the generating principle of the working clock frequency is that the frequency can be the carrier frequency of the time code of integer frequency division to low frequency; the GNSS receiver outputs the demodulated and output 1PPS timing signal and the time code information to a time signal selector, the time signal selector judges the 1PPS signal input by the GNSS receiver and the 1PPS timing signal generated by internal frequency division, the principle of internal input of 1PPS is preferentially selected for automatic selection and switching, and then the 1PPS timing signal is output; and in the same way, selecting the time code information, and preferentially selecting the internal time code information.
The signal generating and converting unit comprises a low-frequency time code coding modulation module, a low-frequency time code signal format parameter configuration module, a delay module, a random noise module and an interference module; the low-frequency time code signal format parameter configuration module selectively outputs a Chinese BPC time code, a Japanese JJY time code or a U.S. WWVB time code according to the signal parameters, correspondingly modulates and codes time code information through the low-frequency time code modulation module and outputs a ground wave signal, and the delay module delays the ground wave signal according to the input sky wave parameters to generate a sky wave signal; the random noise module generates and outputs a noise signal according to the input noise parameter; the interference module generates an interference signal according to the input interference parameter.
The signal synthesis output unit comprises a digital-to-analog conversion module, an amplitude adjusting module, a signal synthesis module and a filter module; the digital-to-analog conversion module converts the ground wave signal, the sky wave signal, the noise signal and the interference signal into analog signals and outputs the analog signals to the amplitude regulation module; the amplitude adjusting module performs amplitude adjusting control according to the input signal amplitude adjusting parameters and then outputs the signals to the signal synthesizing module; and finally, outputting a low-frequency time code time service signal after filtering.
Referring to fig. 1, in an embodiment of the present invention, a low frequency time code simulator includes a simulator control unit, a time frequency generating unit, a signal generating and converting unit, and a signal synthesizing and outputting unit. The simulator control unit configures parameters of the simulator according to keyboard input, such as selection of a low-frequency time code service station, setting of signal amplitude, selection of internal and external frequency labels and the like, displays related parameters through a liquid crystal display screen, and outputs time code information of the GNSS receiver to the low-frequency time code signal generating and converting unit. The time frequency generating unit selects frequency and time source according to the time frequency parameter input by the simulator control unit, and outputs 10MHz frequency signal and 1PPS timing signal to the signal generating and converting unit; the signal generating and converting unit simulates to generate a multi-frequency point low-frequency time code time service signal, adjusts the phase consistency of the output signal, outputs a ground wave signal, a sky wave signal, an interference signal and random noise, and outputs the four paths of signals to the signal synthesizing and outputting unit; the signal synthesis output unit converts the four paths of signals into analog signals through a digital-to-analog converter, adjusts the amplitude of ground wave signals, sky wave signals, interference signals and random noise according to the parameters output by the simulator control unit, and generates and outputs low-frequency time code timing signals.
Referring to fig. 2, in an embodiment of the present invention, the simulator control unit includes a GNSS receiver, a keyboard, a liquid crystal display, a data transmission module, a display control module, and a data processing module. The GNSS receiver selects a GPS or Beidou timing receiver and provides time code information and a 1PPS timing signal; the keyboard is mainly used for inputting parameters; the liquid crystal display is used for displaying the current state of the analog source; the data transmission module is used for decoding and converting GNSS receiver and keyboard input information; the display control module is used for controlling the state and display information of the display; the data processing module is used for converting the parameter classification input by the keyboard into a logic signal which can be identified by the simulator, wherein the functions of the data transmission module, the display control module and the data processing module are all realized by ARM STM32F 4.
Referring to fig. 3, in the embodiment of the present invention, the time frequency generating unit mainly includes a constant temperature crystal oscillator, a frequency selector, a clock management chip, and a time signal selector. The constant-temperature crystal oscillator adopts 10MHz frequency output and provides a reference working frequency signal for the simulator; the clock management chip adopts an AD9516 chip of ADI company, and can carry out frequency multiplication and frequency division operation on 10MHz frequency signals so as to generate working clock frequency which is convenient and available for FPGA and carrier signals for generating low-frequency time code signals; the frequency selector and the time signal selector are realized by FPGA programming; the FPGA uses an EP3C120 chip from Altera corporation.
Referring to fig. 4, in the embodiment of the present invention, the signal generating and converting unit mainly includes a low frequency time code modulation module, a delay module, a low frequency time code signal format parameter configuration module, a random noise module, and an interference module. The low-frequency time code signal format parameter configuration module is internally provided with a Chinese BPC signal, a U.S. WWVB signal and Japanese JJY40 and JJY60 signal code modulation modes, and can perform modulation output on multi-frequency point low-frequency time code information according to different code modulation modes through the low-frequency time code modulation module through the parameter selection of a user and perform phase consistency adjustment; the delay module delays the ground wave signal according to the input sky wave parameters to generate a sky wave signal; the random noise module generates random noise according to the input noise parameters; the interference module generates an interference signal according to the input interference parameter.
Referring to fig. 5, in the embodiment of the present invention, the signal synthesis output unit mainly includes a digital-to-analog conversion module, an amplitude adjustment module, a signal synthesis module, and a filtering module. The digital-to-analog conversion module converts a digital signal into an analog signal by adopting a DAC AD 9744; the amplitude adjusting module is realized by adopting an amplifier AD8041 and a numerical control attenuator HMC472, and completes the amplitude control of the signal according to the input signal amplitude adjusting parameter; the signal synthesis module is realized by adopting a power synthesizer, and finally, a low-frequency time code time service signal is output after passing through the filter module.
Claims (5)
1. The utility model provides a low frequency time code time service signal simulator, includes simulator control unit, time frequency generation unit, signal generation and converting unit and signal synthesis output unit, its characterized in that: the simulator control unit controls the selection of frequency points, the control of amplitude, the presence or absence and the amplitude of interference and noise according to external input; the time frequency generating unit selects a frequency and a time source according to the time frequency signal provided by the simulator control unit and outputs a 10MHz frequency signal and a 1PPS timing signal to the signal generating and converting unit; the signal generating and converting unit simulates to generate a multi-frequency point low-frequency time code time service signal, adjusts the phase consistency of the output signal, and outputs a ground wave signal, a sky wave signal, an interference signal and a random noise four-way signal to the signal synthesis output unit; the signal synthesis output unit converts the four paths of signals into analog signals through a digital-to-analog converter, adjusts the amplitude of ground wave signals, sky wave signals, interference signals and random noise according to the parameters output by the simulator control unit, and generates and outputs low-frequency time code timing signals.
2. The low frequency time code timing signal simulator of claim 1, wherein: the simulator control unit comprises a keyboard, a liquid crystal display screen, a GNSS receiver and a simulation source central processing unit; the central processing unit receives configuration information input by the keyboard and transmits characteristic parameters of signals being output to the liquid crystal display screen for display, the GNSS receiver is a GPS or Beidou receiver, and the central processing unit transmits time code information and position information demodulated by the GNSS receiver to the time frequency generation unit and the signal generation and conversion unit.
3. The low frequency time code timing signal simulator of claim 1, wherein: the time frequency generating unit comprises a constant temperature crystal oscillator, a frequency selector, a time signal selector and a clock management chip; the 10MHz signal of external input and 10MHz signal that the constant temperature crystal oscillator that the simulator is from taking produces output to the frequency selector respectively, the frequency selector chooses two 10MHz frequency signals, and the internal 10MHz signal that the preferred choice simulator is from, 10MHz signal enters the clock management chip and produces the working clock, the frequency of the working clock can be divided to the low frequency time code carrier frequency by the integer; the GNSS receiver outputs the demodulated and output 1PPS timing signal and the time code information to a time signal selector, the time signal selector judges the 1PPS signal input by the GNSS receiver and the 1PPS timing signal generated by internal frequency division, the 1PPS internal input is preferentially selected, and then the 1PPS timing signal is output; and in the same way, selecting the time code information, and preferentially selecting the internal time code information.
4. The low frequency time code timing signal simulator of claim 1, wherein: the signal generating and converting unit comprises a low-frequency time code coding modulation module, a low-frequency time code signal format parameter configuration module, a delay module, a random noise module and an interference module; the low-frequency time code signal format parameter configuration module selectively outputs a Chinese BPC time code, a Japanese JJY time code or a U.S. WWVB time code according to the signal parameters, correspondingly modulates and codes time code information through the low-frequency time code modulation module and outputs a ground wave signal, and the delay module delays the ground wave signal according to the input sky wave parameters to generate a sky wave signal; the random noise module generates and outputs a noise signal according to the input noise parameter; the interference module generates an interference signal according to the input interference parameter.
5. The low frequency time code timing signal simulator of claim 1, wherein: the signal synthesis output unit comprises a digital-to-analog conversion module, an amplitude regulation module, a signal synthesis module and a filter module; the digital-to-analog conversion module converts the ground wave signal, the sky wave signal, the noise signal and the interference signal into analog signals and outputs the analog signals to the amplitude regulation module; the amplitude adjusting module performs amplitude adjusting control according to the input signal amplitude adjusting parameters and then outputs the signals to the signal synthesizing module; and finally, outputting a low-frequency time code time service signal after filtering.
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Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5717402A (en) * | 1994-12-09 | 1998-02-10 | Chu; Peter | GPS reference clock generator |
| CN102565817A (en) * | 2011-12-20 | 2012-07-11 | 中国科学院国家授时中心 | Roland-C timing signal simulator |
| CN102830611A (en) * | 2012-09-05 | 2012-12-19 | 飞亚达（集团）股份有限公司 | Time source |
| CN102968051A (en) * | 2011-08-31 | 2013-03-13 | 精工爱普生株式会社 | Electronic timepiece |
Family Cites Families (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6308077B1 (en) * | 1992-10-02 | 2001-10-23 | Motorola, Inc. | Apparatus and method for providing synchronization of base-stations in a communication system |
| DE19541363A1 (en) * | 1995-11-07 | 1997-05-15 | Deutsche Telekom Ag | Digital signal radio transmission method between mobile transmitter and receiver |
| JP3139399B2 (en) * | 1996-12-18 | 2001-02-26 | 日本電気株式会社 | Satellite internal time system |
| DE10357201A1 (en) * | 2003-12-08 | 2005-07-07 | Atmel Germany Gmbh | Radio Clock |
| CN102386913A (en) * | 2010-08-27 | 2012-03-21 | 亚旭电脑股份有限公司 | Method and device for correcting oscillating frequency |
-
2020
- 2020-04-13 CN CN202010284147.3A patent/CN111538228B/en active Active
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5717402A (en) * | 1994-12-09 | 1998-02-10 | Chu; Peter | GPS reference clock generator |
| CN102968051A (en) * | 2011-08-31 | 2013-03-13 | 精工爱普生株式会社 | Electronic timepiece |
| CN102565817A (en) * | 2011-12-20 | 2012-07-11 | 中国科学院国家授时中心 | Roland-C timing signal simulator |
| CN102830611A (en) * | 2012-09-05 | 2012-12-19 | 飞亚达（集团）股份有限公司 | Time source |
Non-Patent Citations (2)
| Title |
|---|
| 低频时码授时系统中的若干理论与工程设计实验研究;刘军;《中国博士学位论文全文数据库基础科学辑》;20020430(第1期);A007-1 * |
| 低频时码接收系统的研究设计;顾卓璟;《中国优秀硕士学位论文全文数据库信息科技辑》;20120526(第10期);136-395 * |
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