CN115529087A - Device and method for extracting signal light position information - Google Patents
Device and method for extracting signal light position information Download PDFInfo
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Abstract
The invention provides a device and a method for extracting signal light position information, wherein the device comprises: a signal generating unit for generating a synchronization signal based on the detected synchronization light and generating an avalanche signal based on the detected signal light; the signal sampling unit is connected with the signal generating unit and is used for respectively sampling the synchronous signal and the avalanche signal based on a serial deserializing technology to obtain a synchronous sampling sequence corresponding to the synchronous signal and a signal sampling sequence corresponding to the avalanche signal; and the sequence decoding unit is connected with the signal sampling unit and used for calculating to obtain the position information of the signal light according to the synchronous sampling sequence and the signal sampling sequence. The signal sampling unit can directly sample the avalanche signal to obtain the signal sampling sequence based on the serial deserializing technology, so that the signal sampling unit and the signal generating unit can be directly connected without adding a processing circuit for performing avalanche signal coincidence and pulse broadening, and the circuit structure of the extracting device is simplified.
Description
Technical Field
The invention relates to the technical field of quantum communication, in particular to a device and a method for extracting signal light position information.
Background
Quantum key distribution, which is a communication technology using single photons or entangled photon pairs as information carriers. In the existing quantum key distribution technology, one end may emit signal light to the other end, and the other end may detect the signal light using an Avalanche Photodiode (APD), generate a corresponding Avalanche signal based on the detected signal light, extract position information from the Avalanche signal, and perform subsequent links (such as basis vector comparison) in quantum key distribution using the position information.
The avalanche signal is a weak signal, and at present, a Time-to-Digital Converter (TDC) chip or a programmable Gate Array (FPGA) with a TDC function is generally used to extract position information in quantum key distribution. Due to the limitation of precision, a TDC chip (or FPGA) cannot directly identify avalanche signals, a processing circuit needs to be additionally arranged between the APD and the TDC chip (or FPGA), avalanche signal coincidence and pulse widening are carried out on the avalanche signals through the processing circuit, processed electric signals are obtained, and then information is extracted from the processed electric signals through the TDC chip (or FPGA). In summary, the circuit structure of the conventional device for extracting the position information of the signal light is complicated.
Disclosure of Invention
In view of the above problems in the prior art, the present application provides an apparatus and a method for extracting signal light position information, so as to simplify the circuit structure of the apparatus for extracting signal light position information.
A first aspect of the present invention provides an apparatus for extracting signal light position information, including:
a signal generating unit for generating a synchronization signal based on the detected synchronization light and generating an avalanche signal based on the detected signal light;
the signal sampling unit is connected with the signal generating unit and is used for respectively sampling the synchronous signal and the avalanche signal based on a serial deserializing technology to obtain a synchronous sampling sequence corresponding to the synchronous signal and a signal sampling sequence corresponding to the avalanche signal; wherein the synchronous sampling sequence and the signal sampling sequence are both composed of a plurality of binary codes;
and the sequence decoding unit is connected with the signal sampling unit and used for calculating the position information of the signal light according to the synchronous sampling sequence and the signal sampling sequence.
Optionally, the signal generating unit includes:
an avalanche photodiode that detects the signal light and outputs an initial avalanche signal based on the detected signal light;
the filter amplifier is connected with the output end of the avalanche photodiode, filters the initial avalanche signal and outputs a filtered avalanche signal;
and the avalanche signal discriminator is connected with the output end of the filter amplifier and is used for carrying out signal discrimination on the filtered avalanche signal to obtain an avalanche signal.
And the synchronous light discriminator generates a synchronous signal according to the detected synchronous light.
Optionally, the extracting apparatus further comprises:
a phase-locked loop unit which generates a synchronous clock signal according to the synchronous signal; wherein the synchronous clock signal is used as a sampling reference clock signal of the signal sampling unit.
Optionally, when the sequence decoding unit calculates the position information of the signal light according to the synchronous sampling sequence and the signal sampling sequence, the sequence decoding unit specifically executes:
identifying a first code following an edge position of a synchronization signal in the sequence of synchronization samples as a first code and identifying a first code following an edge position of an avalanche signal in the sequence of signal samples as a second code;
setting each code in the synchronous sampling sequence except the first code to be 0, and setting each code in the signal sampling sequence except the second code to be 0;
and counting the number of codes between each second code and the first code which is positioned before the second code and is closest to the second code for each second code, and calculating the position information of the signal light corresponding to the second code according to the number of codes and the sampling rate of the signal sampling unit.
Optionally, the sequence coding unit is further configured to:
and correcting the position information of the signal light by using the delay deviation measured in advance to obtain the corrected position information.
A second aspect of the present invention provides a method for extracting signal light position information, including:
generating a synchronization signal from the detected synchronization light and generating an avalanche signal from the detected signal light;
respectively sampling the synchronous signal and the avalanche signal based on a serial deserializing technology to obtain a synchronous sampling sequence corresponding to the synchronous signal and a signal sampling sequence corresponding to the avalanche signal;
and calculating to obtain the position information of the signal light according to the synchronous sampling sequence and the signal sampling sequence.
Optionally, the generating an avalanche signal according to the detected signal light includes:
outputting an initial avalanche signal based on the detected signal light;
filtering the initial avalanche signal and outputting a filtered avalanche signal;
and carrying out signal discrimination on the filtered avalanche signal to obtain an avalanche signal.
Optionally, the method further includes:
generating a synchronous clock signal according to the synchronous signal; wherein the synchronization clock signal is used as a sampling reference clock signal for sampling the synchronization signal and the avalanche signal.
Optionally, the obtaining, by calculation, position information of the signal light according to the synchronous sampling sequence and the signal sampling sequence includes:
identifying a first code following an edge position of a synchronization signal in the sequence of synchronization samples as a first code and identifying a first code following an edge position of an avalanche signal in the sequence of signal samples as a second code;
setting each code in the synchronous sampling sequence except the first code to be 0, and setting each code in the signal sampling sequence except the second code to be 0;
and counting the number of codes between each second code and the first code which is positioned before the second code and is closest to the second code for each second code, and calculating the position information of the signal light corresponding to the second code according to the number of codes and the sampling rate of the signal sampling unit.
Optionally, after the position information of the signal light is obtained by calculation according to the synchronous sampling sequence and the signal sampling sequence, the method further includes:
and correcting the position information of the signal light by using the delay deviation measured in advance to obtain the corrected position information.
The invention provides a device and a method for extracting signal light position information, wherein the device comprises: a signal generating unit for generating a synchronization signal based on the detected synchronization light and generating an avalanche signal based on the detected signal light; the signal sampling unit is connected with the signal generating unit and is used for respectively sampling the synchronous signal and the avalanche signal based on a serial deserializing technology to obtain a synchronous sampling sequence corresponding to the synchronous signal and a signal sampling sequence corresponding to the avalanche signal; the synchronous sampling sequence and the signal sampling sequence are both formed by a plurality of binary codes; and the sequence decoding unit is connected with the signal sampling unit and used for calculating the position information of the signal light according to the synchronous sampling sequence and the signal sampling sequence. The signal sampling unit can directly sample the avalanche signal to obtain the signal sampling sequence based on the serial deserializing technology, so the signal sampling unit and the signal generating unit can be directly connected without adding a processing circuit for performing avalanche signal coincidence and pulse broadening, and the circuit structure of the extracting device is simplified.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the provided drawings without creative efforts.
Fig. 1 is a schematic diagram of a conventional apparatus for extracting signal light position information;
fig. 2 is a schematic structural diagram of an apparatus for extracting signal light position information according to an embodiment of the present disclosure;
fig. 3 is a schematic structural diagram of an apparatus for extracting signal light position information according to another embodiment of the present application;
fig. 4 is a schematic diagram of an original sample sequence and a decoded sample sequence provided in an embodiment of the present application;
FIG. 5 is a schematic diagram illustrating a principle of determining a delay variation according to an embodiment of the present application;
fig. 6 is a flowchart of a method for extracting signal light position information according to an embodiment of the present disclosure.
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 quantum key distribution technology in practical use usually uses a single photon as an information carrier, and the photon carrying information is called signal light. The basic principle is that a sending end sends synchronous light and signal light to a receiving end according to a certain frequency, the receiving end detects the signal light by using a single-photon detector, a corresponding electric signal is output when the single-photon detector detects one signal light, a subsequent processing device can extract position information of the signal light corresponding to the electric signal according to the electric signal, and then the receiving end can perform subsequent operations such as vector comparison and the like by using the position information and other information of the signal light to complete a quantum key distribution process.
The position information of the signal light refers to a time difference between the signal light and the most recent sync light detected before the signal light. The transmitting frequency of the synchronizing light is less than the transmitting frequency of the signal light, so that after receiving one synchronizing light each time, the receiving end can detect a plurality of signal lights, and for each signal light, the time difference between the time when the receiving end detects the signal light and the time when the receiving end receives the synchronizing light for the last time is the position information of the signal light.
An Avalanche Photodiode (APD) operating in a geiger mode (geigerma) is a single Photon detector commonly used in the field of quantum communication at present. In this mode, the detected signal light enters the APD to cause an avalanche effect, so that the APD outputs a weak avalanche current pulse signal (i.e. an electrical signal corresponding to the detected signal light, which may be referred to as an avalanche signal), and after the avalanche signal output by the APD is transmitted to a subsequent extraction device, the extraction device can extract the position information of the corresponding signal light from the avalanche signal.
The pulse width of the avalanche signal is generally only 400 picoseconds (ps) to 2 nanoseconds (ns), the signal width is very narrow, and as described in the background art, a TDC chip (or an FPGA with a TDC function) used in the existing device for extracting position information cannot directly identify the avalanche signal, so that the current device for extracting signal light position information needs to provide a processing circuit (as shown in fig. 1) for performing avalanche signal coincidence and pulse spreading between the APD and the TDC chip (or the FPGA with a TDC function) to convert the avalanche signal into an electrical signal that can be identified by the TDC chip (or the FPGA with a TDC function). In summary, in the prior art, when extracting the position information from the avalanche signal, a relatively complex processing circuit needs to be provided, which increases the complexity of the system, is prone to malfunction, and is not easy to maintain.
The key point of the scheme is that a signal sampling unit based on a serial deserializing technology is used for directly sampling an avalanche signal, and then the position information of signal light corresponding to the avalanche signal is extracted through a sampling sequence obtained through sampling, so that a processing circuit for performing avalanche signal coincidence and pulse broadening is avoided, and the effect of simplifying the circuit structure is achieved.
A Serdes (Serializer/Deserializer) technology is a technology widely used in the digital communication field, and a communication device designed based on the Serdes technology generally includes a Physical Coding Sublayer (PCS) and a Physical media Attachment (Physical media Attachment) pma Layer. The PMA layer is mainly used for serialization and deserialization, and the PCS layer is mainly used for line coding and Cyclic Redundancy Check (CRC) Check coding.
And removing the physical coding sublayer in the communication device, and only reserving the PMA layer to obtain the serializer and deserializer with the serialization and deserialization functions. The serializer and deserializer can directly sample the external pulse signals which are shaped and differentially processed to obtain a corresponding sampling sequence. The sampling sequence is composed of a plurality of binary codes, each binary code corresponds to one sampling, wherein if the pulse signal is at a high level during sampling, the binary code obtained by the sampling is 1, and if the pulse signal is at a low level during sampling, the binary code obtained by the sampling is 0.
The present solution is specifically described below with reference to the accompanying drawings.
Referring to fig. 2, an embodiment of the present application provides an apparatus for extracting signal light position information, including:
a signal generating unit 201 for generating a synchronization signal based on the detected synchronization light and generating an avalanche signal based on the detected signal light.
The signal generating unit can detect the synchronous light and the signal light in real time, when the synchronous light is detected, the output synchronous signal is a high-level pulse signal, when the synchronous light is not detected, the output synchronous signal is a low-level signal, similarly, when the signal light is detected, the output avalanche signal is a pulse signal, and when the signal light is not detected, the output avalanche signal is a low-level signal.
And the signal sampling unit 202 is connected to the signal generating unit and is configured to sample the synchronization signal and the avalanche signal based on a serial deserializing technique, so as to obtain a synchronization sampling sequence corresponding to the synchronization signal and a signal sampling sequence corresponding to the avalanche signal.
The synchronous sampling sequence and the signal sampling sequence are both formed by a plurality of binary codes.
And the sequence decoding unit 203 is connected with the signal sampling unit and is used for calculating and obtaining the position information of the signal light according to the synchronous sampling sequence and the signal sampling sequence.
The signal sampling unit may specifically include a level shifter and the serializer, where the level shifter is configured to convert both the synchronization signal and the avalanche signal output by the signal generating unit into a differential signal, and then the differential synchronization signal and the differential avalanche signal are input into the serializer and sampled by the serializer.
In the device for extracting the signal light position information provided in this embodiment, after the signal generating unit outputs the synchronization signal and the avalanche signal, the synchronization signal and the avalanche signal are converted into a differential form in the signal sampling unit, and then enter the serializer/deserializer through a high-speed interface of the serializer of the signal sampling unit, and the serializer deserializer samples the synchronization signal and the avalanche signal respectively according to a pre-configured sampling rate and a serial-parallel conversion bit width, so as to obtain a synchronization sampling sequence and a signal sampling sequence.
The sampling rate of the serializer can be set according to the pulse width of each pulse signal in the avalanche signal, the lower the pulse width is, the higher the sampling rate needs to be set, generally, the pulse width of the avalanche signal usually exceeds 400ps, so the sampling rate can be set to a value capable of identifying a pulse signal with a width of 400 ps.
For example, the sampling rate may be set to 10Gbps and the serial-to-parallel bit width may be set to 80 bits.
Optionally, referring to fig. 3, in the extraction apparatus of signal light position information provided in the present application, the signal generation unit 201 may specifically include:
an avalanche photodiode that detects the signal light and outputs an initial avalanche signal based on the detected signal light;
the filter amplifier is connected with the output end of the avalanche photodiode, filters the initial avalanche signal and outputs the filtered avalanche signal;
and the avalanche signal discriminator is connected with the output end of the filter amplifier and is used for carrying out signal discrimination on the filtered avalanche signal to obtain an avalanche signal.
And the synchronous light discriminator generates a synchronous signal according to the detected synchronous light.
A discriminator is a commonly used signal processing device, and is generally used for discriminating an input electrical signal, and specifically, converting an electrical signal whose amplitude exceeds (or falls below) a certain set level into an output signal whose amplitude and width meet certain standards.
Generally, in the field of quantum key distribution, a commonly used synchronous light discriminator itself includes a photoelectric converter for detecting synchronous light, and when each synchronous light irradiates the photoelectric converter, the photoelectric converter outputs a pulse signal, and the pulse signal is discriminated to obtain the synchronous signal.
Or, when the synchronous light discriminator does not include a photoelectric converter, a photoelectric converter may be connected in front of the synchronous light discriminator to detect synchronous light, and a synchronous signal obtained by the detection may be input to the synchronous light discriminator.
In the device for extracting the position information of the signal light, a signal sampling unit needs to be driven by a sampling reference clock signal to sample an input electric signal.
In some alternative embodiments, the apparatus may generate the sampling reference clock signal based on a clock local to the receiving end, in which case the sampling precision of the signal sampling unit is not high, so this scheme is generally used when the precision requirement is low.
In other alternative embodiments, as shown in fig. 3, the device for extracting the signal light position information may include a phase-locked loop unit, and the phase-locked loop unit may generate a synchronous clock signal according to the aforementioned synchronous signal, and then input the synchronous clock signal to the signal sampling unit to drive the signal sampling unit to sample as a sampling reference clock signal of the signal sampling unit. The scheme is generally suitable for systems with high precision requirements, and is beneficial to improving the accuracy of the position information of the extracted signal light by generating a sampling reference clock signal based on the synchronous light.
The synchronous signal output by the synchronous optical discriminator and the avalanche signal output by the avalanche signal discriminator belong to single-ended signals. Therefore, as shown in fig. 3, the synchronization signal output by the synchronization light discriminator and the avalanche signal output by the avalanche signal discriminator may be shaped and differentially processed by corresponding devices to obtain a differential synchronization signal and a differential avalanche signal, and then the differential synchronization signal and the differential avalanche signal enter the signal sampling unit 202 for sampling.
As an example, the frequency of the synchronous clock signal may be 125MHz.
Specifically, the phase-locked loop unit may perform a frequency multiplication operation on the input synchronization signal, so as to obtain a synchronization clock signal homologous to the synchronization signal.
Referring to fig. 3, the signal sampling unit and the sequence decoding unit in the apparatus provided by the present invention may be FPGA devices with corresponding functions.
Optionally, when the sequence decoding unit calculates the position information of the signal light according to the synchronous sampling sequence and the signal sampling sequence, the following steps are specifically executed:
1.1, identifying a first code after the edge position of the synchronous signal in the synchronous sampling sequence as a first code, and identifying a first code after the edge position of the avalanche signal in the signal sampling sequence as a second code.
And 1.2, setting each code except the first code in the synchronous sampling sequence to be zero, and setting each code except the second code in the signal sampling sequence to be zero.
The processes of 1.1 and 1.2 may be referred to as decode operations.
And 1.3, counting the number of codes between the second code and the first code which is positioned before the second code and is closest to the second code aiming at each second code, and calculating the position information of the signal light corresponding to the second code according to the number of codes and the sampling rate of the signal sampling unit.
The following describes the process of calculating the position information of the signal light with reference to fig. 4:
it should be noted that the sampling of the synchronization signal and the avalanche signal is performed synchronously, that is, each sampling is performed by obtaining a binary code of the synchronization sampling sequence and a binary code of the signal sampling sequence simultaneously, in other words, each binary code of the signal sampling sequence and each binary code of the synchronization sampling sequence are in one-to-one correspondence.
The upper diagram of fig. 4 is an original sampling sequence, that is, a synchronous sampling sequence and a signal sampling sequence obtained by sampling by the signal sampling unit, where a signal above the synchronous sampling sequence is a synchronous signal, each high-level pulse of which corresponds to one detected synchronous light, and a signal above the signal sampling sequence is an avalanche signal, each pulse of which corresponds to one detected signal light.
It can be seen that, in the original synchronous sampling sequence, the binary codes obtained by sampling in the pulses corresponding to the synchronous light are all 1, and similarly, in the original signal sampling sequence, the binary codes obtained by sampling in the pulses corresponding to the signal light are all 1.
After the decoding operation is performed on the original sample sequence, a decoded sample sequence as shown in the lower part of fig. 4 can be obtained.
Specifically, when the decoding operation is performed, the coded segment consisting of consecutive 1 s in the synchronous sampling sequence indicates that there is a pulse of the synchronous light at the position, and accordingly, the first code of the segment is the first code after the edge position of the pulse corresponding to the synchronous light, so that the first binary code of the coded segment can be identified as the first code, the first code is kept as 1, and the other codes in the segment after the first code are all set as 0.
Similarly, when the decoding operation is performed, the coded segment consisting of consecutive 1 s in the signal sampling sequence indicates that there is a pulse of the signal light at the position, and accordingly, the first code of the segment is the first code after the edge position of the pulse corresponding to the signal light, so that the first binary code of the coded segment can be identified as the second code, the second code is kept as 1, and the other codes in the segment after the first code are all set as 0.
It can be seen that, in the decoded signal sampling sequence, each second code corresponds to an edge position of a pulse of a signal light, in other words, each second code corresponds to a detected signal light, and similarly, in the decoded synchronous sampling sequence, each first code corresponds to a detected synchronous light.
And finally, counting the number of codes between the second code and the first code which is positioned before the second code and is closest to the second code aiming at each second code, and calculating to obtain the position information of the signal light corresponding to the second code according to the number of codes and the sampling rate of the signal sampling unit.
Specifically, referring to fig. 4, assuming that the counted number of codes for a second code is N, the position information of the signal light corresponding to the second code, that is, the time difference between the corresponding signal light and the latest synchronization light detected before the signal light, is N × f, where f is the time precision corresponding to the sampling rate. If the rate is 10Gbps, f equals 100ps.
Optionally, it takes a certain time (delay) for the synchronization light and the signal light sent by the sending end to reach the receiving end, the propagation paths of the synchronization light and the signal light from the sending end to the receiving end may be different, and there may be a certain delay deviation between the delay when the corresponding synchronization light reaches the receiving end and the delay when the signal light reaches the receiving end, which may result in inaccurate position information of the extracted signal light, therefore, the sequence decoding unit may also be used:
the position information of the signal light is corrected by a delay time difference measured in advance, and the corrected position information is obtained.
Alternatively, the method for determining the delay time deviation may be:
referring to fig. 5, a transmitting end may transmit a signal light for determining a delay deviation, and then transmit a time deviation S1 (i.e., position information of the signal light) between the signal light and a synchronization light to a receiving end through a classical channel, after the receiving end detects the signal light, the receiving end extracts the position information of the signal light as S2 through the extracting apparatus of the position information of the signal light provided by the present invention, and finally, the receiving end calculates a deviation S between S1 and S2, i.e., S = S2-S1, which is a delay deviation of the synchronization light and the signal light.
The invention provides an extraction device of signal light position information, comprising: a signal generating unit for generating a synchronization signal based on the detected synchronization light and generating an avalanche signal based on the detected signal light; the signal sampling unit is connected with the signal generating unit and is used for respectively sampling the synchronous signal and the avalanche signal based on a serial deserializing technology to obtain a synchronous sampling sequence corresponding to the synchronous signal and a signal sampling sequence corresponding to the avalanche signal; the synchronous sampling sequence and the signal sampling sequence are both formed by a plurality of binary codes; and the sequence decoding unit is connected with the signal sampling unit and used for calculating to obtain the position information of the signal light according to the synchronous sampling sequence and the signal sampling sequence. The signal sampling unit can directly sample the avalanche signal to obtain the signal sampling sequence based on the serial deserializing technology, so the signal sampling unit and the signal generating unit can be directly connected without adding a processing circuit for performing avalanche signal coincidence and pulse broadening, and the circuit structure of the extracting device is simplified.
The invention directly samples the avalanche signal by using the serial deserializing technology, has high conversion efficiency and small dead time of pulse signal identification, does not need pulse widening, reduces the complexity of an extraction device and simplifies the circuit structure of the device for extracting the position information. The serial deserializing technology without the coding layer is used, the measurement precision is less influenced by temperature,
furthermore, the signal sampling unit uses a synchronous signal frequency multiplication as a sampling reference clock signal during sampling, so that the position information distribution can be completely reserved in the process of sampling the avalanche signal.
With reference to fig. 6, the method for extracting the position information of the signal light according to the embodiment of the present application may include the following steps:
s601, generating a synchronization signal according to the detected synchronization light, and generating an avalanche signal according to the detected signal light.
Step S601, equivalently, after the avalanche signal discriminator discriminates, an avalanche signal is output, and after the synchronous light discriminator discriminates, a synchronous signal is output.
And S602, sampling the synchronous signal and the avalanche signal respectively based on a serial deserializing technology to obtain a synchronous sampling sequence corresponding to the synchronous signal and a signal sampling sequence corresponding to the avalanche signal.
Step S602, equivalently, the synchronization signal and the avalanche signal are subjected to level conversion and then are accessed to the serializer and deserializer, and the serializer and deserializer samples the synchronization signal and the avalanche signal simultaneously according to the configured running rate and the serial-parallel conversion bit width to obtain a corresponding sampling sequence.
The deserializer may be an FPGA device embedded with a Serdes chip.
And S603, calculating to obtain the position information of the signal light according to the synchronous sampling sequence and the signal sampling sequence.
Step S603 is equivalent to identifying the first code after the edge position in the synchronization sequence and the signal sequence as an effective code, and counting the number of 0S between the synchronization optical sequence and the signal optical sequence, where if N, the corresponding time information is N × f, where f is the precision corresponding to the sampling rate. If the sampling rate is set to 10Gbps, f =100ps, and the time information is the position information of the corresponding signal light.
Optionally, generating an avalanche signal according to the detected signal light includes:
outputting an initial avalanche signal based on the detected signal light;
filtering the initial avalanche signal, and outputting the filtered avalanche signal;
and carrying out signal discrimination on the filtered avalanche signal to obtain the avalanche signal.
Optionally, the method further includes:
generating a synchronous clock signal according to the synchronous signal; wherein the synchronous clock signal is used as a sampling reference clock signal for sampling the synchronous signal and the avalanche signal.
Optionally, the calculating the position information of the signal light according to the synchronous sampling sequence and the signal sampling sequence includes:
identifying a first code after the edge position of the synchronous signal in the synchronous sampling sequence as a first code, and identifying a first code after the edge position of the avalanche signal in the signal sampling sequence as a second code;
setting each code except the first code in the synchronous sampling sequence to be zero, and setting each code except the second code in the signal sampling sequence to be zero;
and counting the number of codes between the second code and the first code which is positioned before the second code and is closest to the second code aiming at each second code, and calculating to obtain the position information of the signal light corresponding to the second code according to the number of codes and the sampling rate of the signal sampling unit.
Optionally, after the position information of the signal light is obtained by calculation according to the synchronous sampling sequence and the signal sampling sequence, the method further includes:
the position information of the signal light is corrected by a delay time difference measured in advance, and the corrected position information is obtained.
In the method for extracting signal light position information provided in the foregoing embodiment, the specific implementation process of each step may refer to the working principle of the device for extracting signal light position information, and is not described herein again.
Finally, it should also be noted that, herein, relational terms such as first and second, and the like may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Also, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrases "comprising a," "8230," "8230," or "comprising" does not exclude the presence of additional like elements in a process, method, article, or apparatus that comprises the element.
It should be noted that the terms "first", "second", and the like in the present invention are only used for distinguishing different devices, modules or units, and are not used for limiting the order or interdependence of the functions performed by the devices, modules or units.
A person skilled in the art can make or use the present application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the application. Thus, the present application is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.
Claims (10)
1. An apparatus for extracting signal light position information, comprising:
a signal generating unit for generating a synchronization signal based on the detected synchronization light and generating an avalanche signal based on the detected signal light;
the signal sampling unit is connected with the signal generating unit and is used for respectively sampling the synchronous signal and the avalanche signal based on a serial deserializing technology to obtain a synchronous sampling sequence corresponding to the synchronous signal and a signal sampling sequence corresponding to the avalanche signal; wherein the synchronous sampling sequence and the signal sampling sequence are each composed of a plurality of binary codes;
and the sequence decoding unit is connected with the signal sampling unit and used for calculating the position information of the signal light according to the synchronous sampling sequence and the signal sampling sequence.
2. The extraction device according to claim 1, wherein the signal generation unit includes:
an avalanche photodiode that detects the signal light and outputs an initial avalanche signal based on the detected signal light;
the filter amplifier is connected with the output end of the avalanche photodiode, filters the initial avalanche signal and outputs a filtered avalanche signal;
the avalanche signal discriminator is connected with the output end of the filter amplifier and is used for carrying out signal discrimination on the filtered avalanche signal to obtain an avalanche signal;
and the synchronous light discriminator generates a synchronous signal according to the detected synchronous light.
3. The extraction device according to claim 1, characterized in that the extraction device further comprises:
a phase-locked loop unit which generates a synchronous clock signal according to the synchronous signal; wherein the synchronous clock signal is used as a sampling reference clock signal of the signal sampling unit.
4. The extraction apparatus according to claim 1, wherein the sequence decoding unit, when calculating the position information of the signal light based on the synchronous sampling sequence and the signal sampling sequence, specifically executes:
identifying a first code following an edge position of a synchronization signal in the sequence of synchronization samples as a first code and identifying a first code following an edge position of an avalanche signal in the sequence of signal samples as a second code;
setting each code in the synchronous sampling sequence except the first code to be 0, and setting each code in the signal sampling sequence except the second code to be 0;
and counting the number of codes between each second code and the first code which is positioned before the second code and is closest to the second code for each second code, and calculating the position information of the signal light corresponding to the second code according to the number of codes and the sampling rate of the signal sampling unit.
5. The extraction apparatus according to claim 1, wherein the sequence coding unit is further configured to:
and correcting the position information of the signal light by using the delay deviation measured in advance to obtain the corrected position information.
6. A method for extracting signal light position information is characterized by comprising the following steps:
generating a synchronization signal from the detected synchronization light and generating an avalanche signal from the detected signal light;
respectively sampling the synchronous signal and the avalanche signal based on a serial deserializing technology to obtain a synchronous sampling sequence corresponding to the synchronous signal and a signal sampling sequence corresponding to the avalanche signal;
and calculating to obtain the position information of the signal light according to the synchronous sampling sequence and the signal sampling sequence.
7. The extraction method according to claim 6, wherein the generating an avalanche signal from the detected signal light comprises:
outputting an initial avalanche signal based on the detected signal light;
filtering the initial avalanche signal and outputting a filtered avalanche signal;
and carrying out signal discrimination on the filtered avalanche signal to obtain an avalanche signal.
8. The extraction method according to claim 6, further comprising:
generating a synchronous clock signal according to the synchronous signal; wherein the synchronization clock signal is used as a sampling reference clock signal for sampling the synchronization signal and the avalanche signal.
9. The extraction method according to claim 6, wherein the calculating the position information of the signal light according to the synchronous sampling sequence and the signal sampling sequence comprises:
identifying a first code following an edge position of a synchronization signal in the sequence of synchronization samples as a first code and identifying a first code following an edge position of an avalanche signal in the sequence of signal samples as a second code;
setting each code in the synchronous sampling sequence except the first code to be 0, and setting each code in the signal sampling sequence except the second code to be 0;
and counting the number of codes between each second code and the first code which is positioned before the second code and is closest to the second code for each second code, and calculating the position information of the signal light corresponding to the second code according to the number of codes and the sampling rate of the signal sampling unit.
10. The extraction method according to claim 6, further comprising, after the calculating the position information of the signal light from the synchronous sampling sequence and the signal sampling sequence, the step of:
and correcting the position information of the signal light by using the delay deviation measured in advance to obtain the corrected position information.
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