CN216490513U - Time-frequency signal transmission device and system - Google Patents
Time-frequency signal transmission device and system Download PDFInfo
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- CN216490513U CN216490513U CN202122948681.2U CN202122948681U CN216490513U CN 216490513 U CN216490513 U CN 216490513U CN 202122948681 U CN202122948681 U CN 202122948681U CN 216490513 U CN216490513 U CN 216490513U
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Abstract
The utility model provides a transmission device and a system of time-frequency signals, wherein the transmission device comprises an optical transmitter and an optical receiver; the optical transmitter is connected with the transmitting terminal equipment; the optical transmitter is connected with the optical receiver through an optical fiber line; the optical transmitter is used for carrying out 'dark pulse' modulation on the time-frequency electric signal sent by the sending terminal equipment and carrying out electro-optical conversion on the modulated time-frequency electric signal to obtain a time-frequency optical signal; the optical receiver is connected with the receiving terminal equipment; the optical receiver performs photoelectric conversion on the time-frequency optical signal transmitted by the optical fiber line to obtain a transmitted time-frequency electric signal, and transmits the transmitted time-frequency electric signal to the receiving terminal equipment. The optical transmitter of the utility model carries out 'dark pulse' modulation on the time-frequency electric signal sent by the sending terminal equipment, and has the advantages of optical fiber line attenuation change resistance, stable transmission time delay and low cost.
Description
Technical Field
The present invention relates to the field of optical fiber transmission technologies, and in particular, to a time-frequency signal transmission device and system.
Background
In many large measurement networks, time-frequency devices are required to perform time synchronization, and a central device sends time synchronization pulses or measurement start pulses, typically transmission Pulse Per Second (PPS), to other terminal devices. Such transmitted signals are characterized by a very low duty cycle, in some cases a pulse signal with a width of tens of ns is emitted within a time interval of one second, and the duty cycle can be as low as 10E-7. When the optical fiber is used as a transmission medium of a time-frequency signal, the length of the optical fiber ranges from several meters to tens of kilometers, and the transmission delay of the signal is changed due to the influence of various environmental factors. This solution is suitable when the length of the optical fiber is long, but for the short distance between the equipments, the length of the optical fiber is within thousands of meters, even tens of meters, the above solution is too complex and costly.
SUMMERY OF THE UTILITY MODEL
The utility model aims to provide a time-frequency signal transmission device and a time-frequency signal transmission system, which have the advantages of optical fiber line attenuation change resistance, stable transmission time delay and low cost.
In order to achieve the purpose, the utility model provides the following scheme:
a device for transmitting a time-frequency signal, comprising:
an optical transmitter and an optical receiver;
the optical transmitter is connected with transmitting terminal equipment; the optical transmitter is connected with the optical receiver through an optical fiber line; the optical transmitter is used for carrying out dark pulse modulation on the time-frequency electric signal sent by the sending terminal equipment and carrying out electro-optical conversion on the modulated time-frequency electric signal to obtain a time-frequency optical signal;
the optical receiver is connected with receiving terminal equipment; and the optical receiver performs photoelectric conversion on the time-frequency optical signal transmitted by the optical fiber line to obtain a transmitted time-frequency electric signal, and transmits the transmitted time-frequency electric signal to a receiving terminal device.
Optionally, the optical transmitter specifically includes:
the device comprises a pulse signal shaping circuit, a laser current driver, a laser, an automatic power controller and a first photoelectric detector;
the input end of the pulse signal shaping circuit is connected with the transmitting terminal equipment; the pulse signal shaping circuit, the laser current driver and the laser are sequentially connected; the output end of the laser is connected with one end of the optical fiber circuit;
the first photoelectric detector is connected with the automatic power controller; the first photoelectric detector is used for detecting a backward optical signal of the laser;
the automatic power controller is used for amplifying the back light signal and controlling the current drive of the laser according to the amplified back light signal to form the closed-loop control of the automatic light power.
Optionally, the optical receiver specifically includes:
the optical attenuator comprises a variable optical attenuator, a second photoelectric detector, a preamplifier, a comparison amplifier, a direct current signal amplifying circuit and an optical attenuator controller;
the variable optical attenuator is connected with the other end of the optical fiber circuit; the variable optical attenuator, the second photoelectric detector, the preamplifier and the comparison amplifier are connected in sequence; the output end of the comparison amplifier is connected with the receiving terminal equipment;
the direct current signal amplifying circuit is respectively connected with the output end of the preamplifier and the input end of the optical attenuator controller; the direct current signal amplifying circuit is used for amplifying the direct current component of the output signal of the preamplifier;
the output end of the optical attenuator controller is connected with the attenuation control end of the variable optical attenuator, and the optical attenuator controller is used for controlling the current drive of the variable optical attenuator according to the direct current component of the output signal of the preamplifier after amplification processing so as to form automatic gain closed-loop control.
Optionally, the optical receiver further includes:
a filter circuit;
the input end of the filter circuit is connected with the output end of the preamplifier;
and the output end of the filter circuit is connected with the input end of the direct current signal amplifying circuit.
A system for transmission of time-frequency signals, comprising:
the system comprises a transmitting terminal device, a plurality of transmission devices of the time-frequency signals and a plurality of receiving terminal devices;
the transmitting terminal equipment is respectively connected with the plurality of transmission devices; and the plurality of transmission devices and the plurality of receiving terminal devices are respectively connected in a one-to-one correspondence manner.
According to the specific embodiment provided by the utility model, the utility model discloses the following technical effects:
the utility model provides a transmission device and a system of time-frequency signals, wherein the transmission device comprises an optical transmitter and an optical receiver; the optical transmitter is connected with the transmitting terminal equipment; the optical transmitter is connected with the optical receiver through an optical fiber circuit; the optical transmitter is used for carrying out dark pulse modulation on the time-frequency electric signal sent by the sending terminal equipment and carrying out electro-optical conversion on the modulated time-frequency electric signal to obtain a time-frequency optical signal; the optical receiver is connected with the receiving terminal equipment; the optical receiver performs photoelectric conversion on the time-frequency optical signal transmitted by the optical fiber line to obtain a transmitted time-frequency electric signal, and transmits the transmitted time-frequency electric signal to the receiving terminal equipment. The optical transmitter of the utility model carries out 'dark pulse' modulation on the time-frequency electric signal sent by the sending terminal equipment, and has the advantages of optical fiber line attenuation change resistance, stable transmission time delay and low cost.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings needed to be used in the embodiments will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings without inventive exercise.
FIG. 1 is a schematic diagram of a transmission apparatus for "bright pulse" modulation of time-frequency signals in the prior art;
fig. 2 is a schematic diagram illustrating a change in amplitude of a pulse signal output by a transmission device for "bright pulse" modulated time-frequency signals in the prior art when the attenuation of an optical fiber changes;
FIG. 3 is a schematic diagram illustrating the variation of the amplitude of the pulse signal output by the transmission device for "bright pulse" modulation time-frequency signals in the prior art when the attenuation of the optical fiber is increased by 5 dB;
FIG. 4 is a schematic structural diagram of a transmission apparatus for modulating a time-frequency signal with "dark pulses" according to an embodiment of the present invention;
description of the drawings: 1-a pulse signal shaping circuit; 2-laser current driver; 3-a laser; 4-an automatic power controller; 5-a first photodetector; 6-variable optical attenuator; 7-an optical attenuator controller; 8-a second photodetector; 9-a preamplifier; 10-a comparison amplifier; 11-a direct current signal amplifying circuit.
Detailed Description
The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
The utility model aims to provide a time-frequency signal transmission device and a time-frequency signal transmission system, which have the advantages of optical fiber line attenuation change resistance, stable transmission time delay and low cost.
In order to make the aforementioned objects, features and advantages of the present invention comprehensible, embodiments accompanied with figures are described in further detail below.
Fig. 4 is a schematic structural diagram of a transmission apparatus for modulating a time-frequency signal by a "dark pulse" in an embodiment of the present invention, as shown in fig. 4, the present invention provides a transmission apparatus for a time-frequency signal, including:
an optical transmitter and an optical receiver;
the optical transmitter is connected with the transmitting terminal equipment; the optical transmitter is connected with the optical receiver through an optical fiber circuit; the optical transmitter is used for carrying out dark pulse modulation on the time-frequency electric signal sent by the sending terminal equipment and carrying out electro-optical conversion on the modulated time-frequency electric signal to obtain a time-frequency optical signal;
the optical receiver is connected with the receiving terminal equipment; the optical receiver performs photoelectric conversion on the time-frequency optical signal transmitted by the optical fiber line to obtain a transmitted time-frequency electric signal, and transmits the transmitted time-frequency electric signal to the receiving terminal equipment.
Specifically, the optical transmitter specifically includes:
the device comprises a pulse signal shaping circuit 1, a laser current driver 2, a laser 3, an automatic power controller 4 and a first photoelectric detector 5;
the input end of the pulse signal shaping circuit is connected with the transmitting terminal equipment; the pulse signal shaping circuit, the laser current driver and the laser are sequentially connected; the output end of the laser is connected with one end of the optical fiber circuit;
the first photoelectric detector is connected with the automatic power controller; the first photoelectric detector is used for detecting a backward optical signal of the laser;
the automatic power controller is used for amplifying the back light signal and controlling the current drive of the laser according to the amplified back light signal to form the closed-loop control of the automatic light power.
Specifically, the optical receiver specifically includes:
a variable optical attenuator 6, a second photodetector 8, a preamplifier 9, a comparison amplifier 10, a direct current signal amplification circuit 11 and an optical attenuator controller 7;
the variable optical attenuator is connected with the other end of the optical fiber circuit; the variable optical attenuator, the second photoelectric detector, the preamplifier and the comparison amplifier are connected in sequence; the output end of the comparison amplifier is connected with the receiving terminal equipment;
the direct current signal amplifying circuit is respectively connected with the output end of the preamplifier and the input end of the optical attenuator controller; the direct current signal amplifying circuit is used for amplifying the direct current component of the output signal of the preamplifier;
the output end of the optical attenuator controller is connected with the attenuation control end of the variable optical attenuator, and the optical attenuator controller is used for controlling the current drive of the variable optical attenuator according to the direct current component of the amplified output signal of the preamplifier to form automatic gain closed-loop control.
Further, the optical receiver further includes:
a filter circuit (not shown herein);
the input end of the filter circuit is connected with the output end of the preamplifier;
the output end of the filter circuit is connected with the input end of the direct current signal amplifying circuit.
As shown in fig. 1, the current pulse optical fiber transceiver solution includes two parts: the pulse signal shaping circuit and the laser current driving circuit form an optical transmitter; the optical receiver is composed of a preamplifier and a comparison amplifier. The optical transmitter completes the electric-optical conversion, and the optical receiver completes the optical-electric conversion and the pulse regeneration.
In the current optical fiber transceiver technical scheme, an optical signal modulation mode of a "bright pulse" mode is adopted, that is: when the pulse occurs, the logic signal is corresponding to '1', and the logic signal is corresponding to 'high optical power level'; when no pulse occurs, a "0" logic signal corresponds to a "no light power level or an extremely low light power level". In an optical transmitter, when a pulse signal-1 signal appears at an input end, a pulse signal shaping circuit generates the 1 signal, so that a laser current driving circuit generates a pulse current to drive a laser to emit light and generate an optical pulse signal corresponding to the pulse signal; when the input end does not generate a pulse signal, namely a '0' signal, the pulse signal shaping circuit generates a '0' signal, so that the laser current driving circuit does not output current to drive the laser, the laser does not emit light, and the output light power is 0 or extremely low light power level.
The light pulse light signal is transmitted to a photoelectric detector in the light-electricity conversion by an optical fiber to be converted into light current, and the light current is amplified by a preamplifier to obtain a pulse signal VpAnd regenerating by the comparison amplifier circuit to finally obtain regenerated pulse output.
In the above process, the optical pulse signal modulated in the "bright pulse" manner is used, and when the pulse duty ratio is low, it is inconvenient to detect the pulse amplitude level in the output optical signal in the optical transmitter to implement the automatic optical power control; in an optical receiver, it is not convenient either to implement automatic gain control to control pulse amplitude stability or to detect well the pulse amplitude level to automatically adjust the comparison threshold level of the comparison amplifier. Therefore, when the pulse is regenerated, the comparison amplifier can only perform comparison amplification by using a fixed comparison threshold level to regenerate the pulse signal, as shown in fig. 2 and 3.
In the example of FIG. 2, the threshold levels V are comparedthTaking a fixed value, e.g. pulse signal V p1/6 of (1). When the attenuation of the optical fiber changes, the amplitude of the pulse signal output by the preamplifier changes correspondingly, and as in the example of fig. 3, after the attenuation of the optical fiber is increased by 5dB, the amplitude of the pulse signal changes from VpIs reduced to V'p，V'p＝Vp/3. Due to comparison of threshold levels VthThe time position of the rising edge of the regenerated pulse signal obtained by the comparison amplifier is changed to be a fixed value, the change is delta t, and the magnitude of delta t is related to the change of the amplitude of the pulse signal and the rising edge rate of the pulse signal. When the variation of the amplitude of the pulse signal is large, for example, 10dB, the rising edge rate of the pulse signal is low, for example, 1ns, and in the above example, the value of Δ t can reach more than 600 ps. In some applications, transmission delay variations of hundreds of ps exceed the tolerance.
As shown in fig. 4, the optical fiber transmission device includes two parts: an optical transmitter and an optical receiver. The optical transmitter performs the electrical-to-optical conversion, and the optical receiver performs the optical-to-electrical conversion and the pulse regeneration.
The optical transmitter includes: pulse signal shaping, laser current driving, automatic power control, a laser and a first photoelectric detector; the pulse signal shaping, the laser current driving and the laser are sequentially connected, the first photoelectric detector detects a backward light signal of the laser, and the backward light signal is amplified by the automatic power control circuit and then is controlled to be driven by the pulse current to form automatic light power closed-loop control, so that the output light power is stable.
The optical receiver includes: the device comprises a variable optical attenuator, an optical attenuator controller, a photoelectric detector 2, a preamplifier, a comparison amplifier and a direct current signal amplifier; the variable optical attenuator, the photoelectric detector 2, the preamplifier and the comparison amplifier are sequentially connected, the direct current signal amplifying circuit filters an output signal of the preamplifier, amplifies an obtained direct current component signal and outputs the amplified direct current component signal to an attenuation control end of the optical attenuator controller to form automatic gain closed-loop control, so that the output signal of the preamplifier is stable and unchanged, and the comparison amplifier adopts a fixed comparison threshold value to perform pulse regeneration.
In the device, a light signal modulation mode of a 'dark pulse' mode is adopted, a pulse signal appears, corresponds to a '1' logic signal and corresponds to 'no light power level or extremely low light power level'; no pulse signal is present, corresponding to a "0" logic signal, corresponding to a "high optical power level". When a pulse signal-1 signal appears at the input end, the pulse signal shaping circuit generates a 1 signal, the laser current driving circuit does not generate pulse current to drive the laser, the laser does not emit light or only emits light with low power, and the output light power is 0 or extremely low light power level; when the input end does not have a pulse signal, namely a '0' signal, the pulse signal shaping circuit generates a '0' signal, the laser current driving circuit outputs current to drive the laser to emit light, and the output light power is high light power.
After the optical signal modulation mode of a 'dark pulse' mode is adopted, because the pulse duty ratio is very low and is lower than 10E-3, at the end of an optical transmitter, the optical signal output by the optical transmitter is an approximately direct-current high-power optical signal in most of time; when a pulse signal is present, the optical transmitter outputs an optical power at a lower value, such as less than-30 dBm. Thus, it is easy to adopt the backward optical signal DC signal amplifying circuit to form the automatic optical power control circuit, so that the average optical power level of the optical signal outputted by the optical transmitter tends to a stable value, such as 0dBm, and the amplitude level value of the optical pulse signal is also approximately equal to the average power level value of the optical signal. Since the amplitude level of the optical pulse is approximately equal to the average output optical power of the laser, the amplitude of the pulse signal in the optical signal can be stabilized by controlling the average output optical power of the optical transmitter to be stable.
After the optical signal modulation method of the "dark pulse" method is adopted, in the embodiment, a preamplifier in the optical receiver simultaneously amplifies a direct current signal and a pulse signal contained in the optical signal, the level of the pulse signal is approximately equal to the level of the direct current signal, and the amplitude level of the pulse signal is obtained by detecting the direct current level of the received optical signal; the DC signal amplifying circuit filters the output signal of the preamplifier and amplifies the obtained DC component signal, then the signal is output to the attenuation control end of the optical attenuator to form automatic gain closed-loop control, so that the output signal of the preamplifier is stable and unchanged, even if the comparison amplifier uses a fixed comparison threshold, the ratio of the amplitude level of the pulse input signal to the comparison threshold level can still be kept almost unchanged, the rising edge time position of the regenerated pulse signal regenerated by the comparison amplifier does not change along with the change of the input pulse signal level, the influence of the amplitude level change of the pulse input signal on the transmission delay is greatly weakened, even if a device with lower speed and smaller bandwidth is adopted, when the loss of the optical fiber line changes, the transmission delay can be ensured to be hardly changed along with the change of the loss of the optical fiber line.
In addition, the utility model also provides a transmission system of the time frequency signal, which comprises the following steps:
the system comprises a transmitting terminal device, a plurality of transmission devices of the time-frequency signals and a plurality of receiving terminal devices;
the transmitting terminal equipment is respectively connected with a plurality of transmission devices; the plurality of transmission devices and the plurality of receiving terminal devices are respectively connected in a one-to-one correspondence manner.
In the present specification, the embodiments are described in a progressive manner, each embodiment focuses on differences from other embodiments, and the same and similar parts among the embodiments are referred to each other. Meanwhile, for a person skilled in the art, according to the idea of the present invention, the specific embodiments and the application range may be changed. In view of the above, the present disclosure should not be construed as limiting the utility model.
Claims (5)
1. A transmission apparatus of time-frequency signals, the transmission apparatus comprising:
an optical transmitter and an optical receiver;
the optical transmitter is connected with transmitting terminal equipment; the optical transmitter is connected with the optical receiver through an optical fiber line; the optical transmitter is used for carrying out dark pulse modulation on the time-frequency electric signal sent by the sending terminal equipment and carrying out electro-optical conversion on the modulated time-frequency electric signal to obtain a time-frequency optical signal;
the optical receiver is connected with receiving terminal equipment; and the optical receiver performs photoelectric conversion on the time-frequency optical signal transmitted by the optical fiber line to obtain a transmitted time-frequency electric signal, and transmits the transmitted time-frequency electric signal to a receiving terminal device.
2. The apparatus for transmitting time-frequency signals according to claim 1, wherein the optical transmitter specifically comprises:
the device comprises a pulse signal shaping circuit, a laser current driver, a laser, an automatic power controller and a first photoelectric detector;
the input end of the pulse signal shaping circuit is connected with the transmitting terminal equipment; the pulse signal shaping circuit, the laser current driver and the laser are sequentially connected; the output end of the laser is connected with one end of the optical fiber circuit;
the first photoelectric detector is connected with the automatic power controller; the first photoelectric detector is used for detecting a backward optical signal of the laser;
the automatic power controller is used for amplifying the back light signal and controlling the current drive of the laser according to the amplified back light signal to form the closed-loop control of the automatic light power.
3. The apparatus for transmitting time-frequency signals according to claim 2, wherein the optical receiver specifically comprises:
the optical attenuator comprises a variable optical attenuator, a second photoelectric detector, a preamplifier, a comparison amplifier, a direct current signal amplifying circuit and an optical attenuator controller;
the variable optical attenuator is connected with the other end of the optical fiber circuit; the variable optical attenuator, the second photoelectric detector, the preamplifier and the comparison amplifier are connected in sequence; the output end of the comparison amplifier is connected with the receiving terminal equipment;
the direct current signal amplifying circuit is respectively connected with the output end of the preamplifier and the input end of the optical attenuator controller; the direct current signal amplifying circuit is used for amplifying the direct current component of the output signal of the preamplifier;
the output end of the optical attenuator controller is connected with the attenuation control end of the variable optical attenuator, and the optical attenuator controller is used for controlling the current drive of the variable optical attenuator according to the direct current component of the output signal of the preamplifier after amplification processing so as to form automatic gain closed-loop control.
4. The apparatus for transmitting time-frequency signals according to claim 3, wherein the optical receiver further comprises:
a filter circuit;
the input end of the filter circuit is connected with the output end of the preamplifier;
and the output end of the filter circuit is connected with the input end of the direct current signal amplifying circuit.
5. A transmission system for time-frequency signals, the transmission system comprising:
a transmitting terminal device, a plurality of transmission means of time-frequency signals according to any of claims 1 to 4, and a plurality of receiving terminal devices;
the transmitting terminal equipment is respectively connected with the plurality of transmission devices; and the plurality of transmission devices and the plurality of receiving terminal devices are respectively connected in a one-to-one correspondence manner.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202122948681.2U CN216490513U (en) | 2021-11-29 | 2021-11-29 | Time-frequency signal transmission device and system |
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| Application Number | Priority Date | Filing Date | Title |
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| CN202122948681.2U CN216490513U (en) | 2021-11-29 | 2021-11-29 | Time-frequency signal transmission device and system |
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| Publication Number | Publication Date |
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| CN216490513U true CN216490513U (en) | 2022-05-10 |
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| CN202122948681.2U Active CN216490513U (en) | 2021-11-29 | 2021-11-29 | Time-frequency signal transmission device and system |
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| CN (1) | CN216490513U (en) |
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- 2021-11-29 CN CN202122948681.2U patent/CN216490513U/en active Active
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