Optical time domain reflectometer and laser driving method thereof
By adopting a laser driving method with random delay time in the OTDR device and using the coherent accumulation method to extract the target signal, the problem that existing OTDR devices cannot achieve miniaturization and low cost is solved, and effective noise suppression and dynamic range improvement are achieved.
Patent Information
- Application Number
- CN202411951751.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-25
- Publication Date
- 2025-05-06
AI Technical Summary
Existing OTDR devices cannot achieve miniaturization and low cost, mainly due to the complex laser driving method, which increases the demand for computing resources.
A laser driving method is adopted to obtain the random delay time, drive the laser emitting component to emit the target laser light, and notify the laser receiving component to receive the reflected laser light, and extract the target signal through a coherent accumulation method.
This method effectively improves noise suppression, improves dynamic range and scanning consistency, and does not require the introduction of additional hardware resources. It can be implemented within the existing system framework, reducing costs and promoting equipment miniaturization.
Smart Images
Figure CN119945543A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to the technical field of optical fiber communication, in particular to an optical time domain reflectometer and a laser driving method thereof. Background Art
[0002] During the OTDR measurement process, due to the influence of some low-frequency signals (such as power supply noise, etc.), in addition, the laser signal may experience multipath transmission, that is, the signal propagates through different paths to reach the receiving end. Low-frequency crosstalk and multipath problems will affect the improvement of the dynamic range, affecting the stability and accuracy of the OTDR equipment measurement results.
[0003] The laser driving method based on coding technology can improve the detection distance and event positioning accuracy of OTDR, so that the device can more accurately identify and locate events or faults in the optical fiber. The use of coding technology requires complex signal encoding and decoding processes, which will increase the demand for computing resources of the device. In particular, the processor performance requirements are high, and additional computing resources and complex circuit design are required, which will increase the cost of the device and is not conducive to making the OTDR module more compact and reducing costs. Summary of the invention
[0004] The technical problem to be solved by the embodiments of the present invention is to provide an optical time domain reflectometer and a laser driving method thereof, so as to solve the problem that the OTDR equipment in the prior art cannot be miniaturized and low-cost.
[0005] The present invention discloses a laser driving method of an optical time domain reflectometer, which is applied to the optical time domain reflectometer. The optical time domain reflectometer includes a laser emitting component and a laser receiving component;
[0006] The laser driving method of the optical time domain reflectometer comprises:
[0007] Obtaining a random delay time length, and driving the laser emission component to emit a target laser based on the random delay time length;
[0008] The random delay duration is notified to the laser receiving component, so that the laser receiving component can receive the reflected laser of the target laser according to the random delay duration, and obtain the target signal in the reflected laser by a coherent accumulation method.
[0009] Optionally, the step of randomly delaying the duration includes:
[0010] Obtain a pseudo-random number pattern, generate a pseudo-random number based on the pseudo-random number pattern, multiply the pseudo-random number by a clock period of the laser emitting component to obtain a first delay duration, and obtain the random delay duration based on the first delay duration.
[0011] Optionally, the step of randomly delaying the duration further includes:
[0012] Acquire a delay working mode, and generate a second delay duration based on the delay working mode, wherein the second delay duration does not exceed the clock cycle;
[0013] The random delay duration is obtained according to the sum of the first delay duration and the second delay duration.
[0014] Optionally, the delay working mode includes one of a random delay mode and a fixed delay mode;
[0015] When the delay working mode is the fixed delay mode, the step of generating a second delay duration based on the delay working mode includes:
[0016] The second delay time is generated based on the first delay time and an initial phase of the target laser.
[0017] Optionally, the step of driving the laser emitting component to emit a target laser based on the random delay duration includes:
[0018] Acquire the frequency and pulse width information of the laser pulse of the target laser, and generate a delay control signal according to the random delay duration;
[0019] A target pulse signal is generated based on the frequency and pulse width information and the delay control signal, and the laser emitting component is driven to emit the target laser based on the target pulse signal.
[0020] Optionally, the step of enabling the laser receiving component to receive the target laser according to the random delay duration includes:
[0021] The laser receiving component samples and caches the target laser according to the random delay time to generate a target signal;
[0022] After the target signal is denoised, event recognition and positioning are performed, event information is acquired, and the event information is reported.
[0023] The present invention also discloses an optical time domain reflectometer, which is used to implement the method described above;
[0024] The optical time domain reflectometer comprises: a controller, a data transmission and communication module connected to the controller, a delay component connected to the data transmission and communication module, a laser emitting component and a laser receiving component;
[0025] The delay component is used to obtain a random delay duration according to an instruction of the controller, the laser emitting component is used to emit a target laser based on the random delay duration, and the laser receiving component is used to receive the target laser according to the random delay duration.
[0026] Optionally, the delay component comprises: a pseudo-random number generation module and a first delay module connected to each other;
[0027] The pseudo-random number generation module is connected to the data transmission and communication module, and is used to obtain a pseudo-random number pattern and generate a pseudo-random number based on the pseudo-random number pattern;
[0028] The first delay module is used to multiply the pseudo-random number by the clock period of the laser emitting component to obtain a first delay duration.
[0029] Optionally, the delay component further includes:
[0030] The second delay module is connected to the data transmission and communication module, and is used to obtain a delay working mode, and generate a second delay duration based on the delay working mode, and the second delay duration does not exceed the clock cycle.
[0031] Optionally, the second delay module is connected to the pseudo-random number generation module, and the delay working mode includes one of a random delay mode and a fixed delay mode;
[0032] When the delay working mode is the fixed delay mode, the second delay module is further used to generate the second delay duration based on the first delay duration and the target initial phase of the target laser.
[0033] Compared with the prior art, the laser driving method of the optical time domain reflectometer provided by the embodiment of the present invention has the beneficial effect that: the target laser is emitted after a delay of a random delay time, the laser receiving component receives the reflected laser of the target laser according to the random delay time, and the target signal in the reflected laser is extracted through a coherent accumulation scheme, and increasing the randomness of the optical pulse phase can effectively enhance the suppression of noise, improve the dynamic range and scanning consistency, and there is no need to introduce additional hardware resources. This technology is implemented within the existing system framework, does not require a large amount of computing resources when processing signals, and can be implemented on a relatively simple processor, which is conducive to reducing costs and realizing miniaturization of equipment. BRIEF DESCRIPTION OF THE DRAWINGS
[0034] The scheme of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments, in which:
[0035] Figure 1 It is a flow chart of a first embodiment of a laser driving method for an optical time domain reflectometer provided by the present invention;
[0036] Figure 2 It is a structural schematic diagram of an embodiment of an optical time domain reflectometer provided by the present invention;
[0037] Figure 3 is a flow chart of a second embodiment of the laser driving method of the optical time domain reflectometer provided by the present invention;
[0038] Figure 4 is a schematic flow chart of a third embodiment of a laser driving method for an optical time domain reflectometer provided by the present invention;
[0039] Figure 5 Schematic diagram of phase comparison between the conventional laser driving method and the phase comparison provided by the present invention.
[0040] The reference numerals in the figures are:
[0041] 10. Optical time domain reflectometer; 11. Controller; 12. Data transmission and communication module; 13. Delay component; 131. Pseudo-random number generation module; 132. First delay module; 133. Second delay module; 14. Laser emission component; 141. Laser drive module; 142. Laser; 15. Laser receiving component; 151. ACD data acquisition module; 152. APD. DETAILED DESCRIPTION
[0042] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. Now, in conjunction with the accompanying drawings, the preferred embodiments of the present invention are described in detail.
[0043] See also Figure 1 and Figure 2 , Figure 1 It is a flow chart of a first embodiment of a laser driving method for an optical time domain reflectometer provided by the present invention. Figure 2 1 is a schematic diagram of the structure of an embodiment of the optical time domain reflectometer provided by the present invention. The optical time domain reflectometer 10 includes a laser emitting component 14 and a laser receiving component 15. The laser emitting component 14 is used to generate and emit a pulsed optical signal into the optical fiber under test. Specifically, a short pulse optical signal is generated by controlling the laser 142, and the short pulse optical signal is injected into the optical fiber under test. The short pulse optical signal will propagate in the optical fiber under test. The laser receiving component 15 is used to receive the reflected optical signal reflected from the optical fiber under test, convert the reflected optical signal into an electrical signal, and analyze and process it. By analyzing the intensity and time delay of the electrical signal, the quality of the optical fiber connection under test, the fault location and the attenuation can be determined.
[0044] The laser driving method of the optical time domain reflectometer provided by the present invention comprises the following steps:
[0045] S101: Obtain a random delay time length, and drive the laser emission component to emit a target laser based on the random delay time length.
[0046] In a specific implementation scenario, before each time the laser emission component 14 is driven to emit the target laser, a random delay duration is first obtained. The length of the random delay duration is randomly generated, so the random delay duration corresponding to each emission of the target laser may be inconsistent. After obtaining the random delay duration, the laser emission component 14 is driven to delay the random delay duration before emitting the target laser. The target laser will be injected into the optical fiber under test, and transmitted and reflected in the optical fiber under test. The random delay duration can be obtained through a random delay element, or generated by the controller 11.
[0047] In other implementation scenarios, after obtaining the random delay time, a delay control signal is generated according to the random delay time, the frequency and pulse width information of the laser pulse of the target laser is obtained, a corresponding pulse signal is generated according to the frequency and pulse width information, and the delay control signal and the pulse signal are combined to generate a target pulse signal. The generated target pulse signal is sent to the laser 142 of the laser emitting component 14, and according to the control of the target pulse signal, the laser 142 can emit a target laser that meets specific requirements. The random delay time of each target laser emission is different, and the corresponding target pulse signal will also be different.
[0048] S102: Notify the laser receiving component of the random delay time, so that the laser receiving component can receive the reflected laser of the target laser according to the random delay time, and obtain the target signal in the reflected laser by a coherent accumulation method.
[0049] In a specific implementation scenario, the random delay duration is notified to the laser receiving component 15, so that the laser receiving component 15 can be in a corresponding receiving state according to the random delay duration, or use the received signal as the reflected laser of the target laser according to the random delay duration.
[0050] Since the interference signal in the optical fiber often has a specific frequency characteristic, and since the target laser in this embodiment has undergone a delay of a random delay time length before being emitted, the target laser has a random initial phase. The laser receiving component 15 obtains the random delay time length, so the reflected laser can be accurately received. After the laser receiving component 15 can convert the reflected laser into an electrical signal, these electrical signals will have different phase information. Through the coherent accumulation method, multiple electrical signals are superimposed under the condition of phase consistency to enhance the strength of the signal. Due to the randomness of the initial phase, the phases of the interference signals carried in the electrical signal are not consistent, so these interference signals will cancel each other out in phase during the accumulation process, reducing their influence. The signal superposition of phase consistency will enhance the strength of the target signal, while the inconsistent phase of the interference signal will cause it to be suppressed during the accumulation process, thereby improving the ratio of signal to interference and enhancing the quality and stability of the signal. Based on high-quality signal analysis and detection, the optical fiber under test can be accurately checked for faults.
[0051] From the above description, it can be seen that in this embodiment, the target laser is emitted after a delay of a random delay time, and the laser receiving component receives the reflected laser of the target laser according to the random delay time, and extracts the target signal in the reflected laser through a coherent accumulation scheme. Increasing the randomness of the optical pulse phase can effectively enhance the suppression of noise, improve the dynamic range and scanning consistency, and there is no need to introduce additional hardware resources. This technology is implemented within the existing system framework, does not require a large amount of computing resources when processing signals, and can be implemented on a relatively simple processor, which is conducive to reducing costs and realizing miniaturization of equipment.
[0052] Please refer to 3. Figure 3 1 is a flow chart of a second embodiment of the laser driving method of the optical time domain reflectometer provided by the present invention. The laser driving method of the optical time domain reflectometer provided by the present invention comprises the following steps:
[0053] S201: Obtain a pseudo-random number pattern, and generate a pseudo-random number based on the pseudo-random number pattern.
[0054] In a specific implementation scenario, a pseudo-random number pattern is obtained. The pseudo-random number pattern is used to define a method for generating pseudo-random numbers. For example, a PRBS (Pseudo-Random Binary Sequence) method can be used. The PRBS sequence has a pseudo-random property and can simulate the characteristics of a random signal while being deterministic and repeatable. For example, PRBS7 and PRBS9. PRBS7 is a 2-bit sequence with a length of 2. 7 -1=127 pseudo-random binary sequence. It consists of 127 bits of binary and can be used to test and evaluate channel performance, bit error rate, etc. in communication systems. PRBS9 is a pseudo-random binary sequence with a length of 29 -1=511 pseudo-random binary sequence. It consists of 511 bits of binary and is longer than PRBS7. PRBS9 sequence is usually used for more stringent performance testing and can provide more data points to evaluate system performance.
[0055] S202: Multiply the pseudo-random number by the clock period of the laser emitting component to obtain a first delay time, and obtain a random delay time according to the first delay time.
[0056] In a specific implementation scenario, the clock period of the laser emitting component 14 is determined, and the generated pseudo-random number is multiplied by the clock period of the laser emitting component 14 to calculate the first delay duration. A random delay duration is obtained according to the first delay duration, which is used to control the laser pulse emission timing of the laser emitting component 14. For example, the calculated first delay duration is applied as the random delay duration, and the first delay duration is added to the original emission time interval of the target laser to obtain the random delay duration, thereby adding randomness to the initial phase of the target laser, which can effectively suppress interference.
[0057] S203: driving the laser emission component to emit a target laser based on a random delay time.
[0058] In a specific implementation scenario, step S203 is substantially consistent with step S101 of the first embodiment of the laser driving method for an optical time domain reflectometer provided by the present invention, and will not be described in detail herein.
[0059] S204: The laser receiving component samples and caches the target laser according to the random delay time to generate a target signal.
[0060] In a specific implementation scenario, the laser receiving component 15 samples the target laser according to the previously calculated random delay time, receives the laser signal of the reflected laser and converts it into a target signal in a digital signal format. The acquired target signal is then cached for subsequent processing.
[0061] S205: After the target signal is denoised, event recognition and positioning are performed, event information is acquired, and the event information is reported.
[0062] In a specific implementation scenario, the cached target signal is subjected to noise reduction processing. The purpose of noise reduction is to remove noise and interference in the signal so as to more accurately identify valid information in the signal. Digital signal processing technology, such as filters, coherence methods, etc., can be applied to remove noise and interference in the target signal.
[0063] After noise reduction, the target signal is subjected to event identification and location. Once the event in the target signal is identified and located, the receiving component extracts relevant event information from it. Event information includes key data such as event type, timestamp, location coordinates, etc. for subsequent processing and analysis. The acquired event information is reported to the system or control center. The reported information can be sent to relevant equipment or personnel through network transmission or other communication methods for further processing, analysis or taking corresponding actions.
[0064] Specifically, signal features, such as amplitude, interval, waveform, pulse width, etc., are extracted from the denoised signal to determine whether the signal features meet the preset event type standards, such as whether the value of the signal feature exceeds a preset threshold. The time intervals and other numerical differences between multiple signal features are used to locate the location where the event occurred.
[0065] From the above description, it can be seen that in this embodiment, a pseudo-random number is generated based on a pseudo-random number pattern, the pseudo-random number is multiplied by the clock period of the laser emitting component to obtain a first delay duration, and a random delay duration is obtained based on the first delay duration, thereby adding randomness to the initial phase of the target laser, which can effectively suppress interference.
[0066] Please refer to Figure 4 , Figure 4 1 is a flow chart of a third embodiment of the laser driving method of the optical time domain reflectometer provided by the present invention. The laser driving method of the optical time domain reflectometer provided by the present invention comprises the following steps:
[0067] S301: Obtain a pseudo-random number pattern, and generate a pseudo-random number based on the pseudo-random number pattern.
[0068] S302: Multiply the pseudo-random number by the clock period of the laser emitting component to obtain a first delay duration.
[0069] In a specific implementation scenario, steps S301-S302 are substantially consistent with the corresponding parts of steps S201-S202 in the second embodiment of the laser driving method for an optical time domain reflectometer provided in the present application, and will not be described in detail here.
[0070] S303: Acquire a delay working mode, generate a second delay duration based on the delay working mode, and acquire a random delay duration according to the sum of the first delay duration and the second delay duration.
[0071] In a specific implementation scenario, a second delay duration is generated as a supplement to the first delay duration. The length of the second delay duration does not exceed the length of one clock cycle. The random delay duration is obtained based on the sum of the first delay duration and the second delay duration. The sum of the first delay duration and the second delay duration can be added to the original emission time interval to obtain the random delay duration, or the sum of the first delay duration and the second delay duration can be directly used as the random delay duration. Please refer to Figure 5 , Figure 5 A schematic diagram of the phase comparison between the conventional laser driving method and the phase comparison provided by the present invention. Figure 5 The upper middle part is a traditional laser driving method, which emits lasers according to a fixed period T, and the time delay before each laser is emitted is T'. The lower middle part is a laser driving method provided by the present invention, and the time delay before each laser is emitted is the sum of the original emission time interval T', the first delay time length NTs, and the second delay time length t, where N is a random number, so it can be seen that the length of each delay is not equal.
[0072] The second delay duration can be used as a supplement to the first delay duration, which can further enhance the randomness, or adjust the initial phase of the target laser. Specifically, the delay working mode includes one of a random delay mode and a fixed delay mode. It can be selected according to actual needs. When the delay working mode is a random delay mode, the second delay duration is a randomly generated duration. The second delay duration can be used as a supplement to the first delay duration, further enhancing the randomness of the initial phase of the target laser, and can effectively improve the effect of noise suppression.
[0073] When the delay working mode is the fixed delay mode, the second delay duration is a specified duration, which is used to accurately adjust the initial phase of the target laser to achieve phase-shifted scanning. Phase-shifted scanning is a technology that can improve the resolution and performance of the scanning system by introducing a certain phase difference. The second delay duration can be achieved by the IO delay unit inside the FPGA. In the FPGA, there is usually a special IO delay unit for implementing the delay of the input / output port. By adjusting the settings of these IO delay units, the delay control of the reflected laser can be achieved. In addition to the IO delay unit, the FPGA also has carry chain resources, which can be used to achieve fast transmission and delay control in logic circuits. These carry chain resources can be used to achieve a smaller range of delays to meet the needs of generating the second delay duration in this embodiment.
[0074] Compared with the dynamic phase method using the FPGA clock, the phase control using the second delay time for phase adjustment has higher accuracy and faster speed. By implementing phase control through a fine delay module, the phase of the optical pulse can be adjusted more accurately, improving the performance and resolution of the system. The second delay time is derived based on the requirements of the first delay time and the initial phase, without involving frequency control or a phase-locked loop, which can avoid the problem of phase-locked loop loss, and can achieve precise control of the initial phase without introducing unnecessary interference and fluctuations. The stability of the system is improved, ensuring the normal operation of the system.
[0075] S304: driving the laser emission component to emit a target laser based on a random delay time.
[0076] S305: Notify the laser receiving component of the random delay time, so that the laser receiving component can receive the reflected laser of the target laser according to the random delay time, and obtain the target signal in the reflected laser by the coherent accumulation method.
[0077] In a specific implementation scenario, steps S304-S305 are substantially consistent with the corresponding contents of steps S101-S102 in the first embodiment of the laser driving method for an optical time domain reflectometer provided by the present invention, and are not further described herein.
[0078] From the above description, it can be seen that in this embodiment, the first delay time is supplemented by the second delay time. According to the actual needs of the user, the randomness of the initial phase of the target laser can be further enhanced to effectively improve the noise suppression effect, and the initial phase of the target laser can be accurately adjusted to achieve phase-shifted scanning and improve the resolution and performance of the scanning system.
[0079] Please continue reading Figure 2 The optical time domain reflectometer 10 includes: a controller 11, a data transmission and communication module 12 connected to the controller 11, a delay component 13 connected to the data transmission and communication module 12, a laser emitting component 14 and a laser receiving component 15. The optical time domain reflectometer 10 can implement the laser driving method of the optical time domain reflectometer 10 described above.
[0080] The laser emitting assembly 14 includes a laser driving module 141 and a laser 142 which are connected to each other. The laser driving module 141 is used to send a driving signal. The laser 142 emits a target laser after receiving the driving signal. The driving signal may include the frequency and pulse width information of the laser pulse. The laser receiving assembly 15 includes an ACD data acquisition module 151 and an APD (Avalanche Photodiode) 152 which are connected to each other. The controller 11 is used to communicate with other modules in the optical time domain reflectometer 10 through the data transmission and communication module 12, send work instructions to other modules, or receive information fed back by other modules.
[0081] The delay component is connected to the data transmission and communication module 12 and to the laser driving module 141. When the controller 11 issues an instruction, the delay component 13 can obtain the random delay duration according to the instruction. For example, the instruction may include a start instruction. The delay component 13 starts the operation based on the start instruction, thereby calculating the random delay duration and sending the random delay duration to the laser driving module 141, so that the laser driving module 141 can output the corresponding driving signal according to the random delay duration, and drive the laser 142 to emit the corresponding target laser. The laser driving module 141 is connected to the ADC data acquisition module, so that the random delay duration can be notified to the ADC data acquisition module, so that it can accurately collect the reflected laser.
[0082] The delay component 13 includes a pseudo-random number generation module 131 and a first delay module 132 connected to each other. The pseudo-random number generation module 131 and the first delay module 132 are both connected to the data transmission and communication module 12, and the first delay module 132 is connected to the laser driving module 141. The pseudo-random number generation module 131 obtains the pseudo-random number generation mode indicated by the controller 11 through the data transmission and communication module 12, such as PRBS7 or PRBS9, and generates a pseudo-random number according to the pseudo-random number generation mode. After the first delay module 132 obtains the pseudo-random number, it multiplies the pseudo-random number with the clock cycle of the laser emission component 14 based on the delay mode indicated by the controller 11 obtained through the data transmission and communication module 12 to obtain the first delay duration. The first delay module 132 notifies the laser driving module 141 of the first delay duration, so that the laser driving module 141 can generate a random delay duration according to the first delay duration, and then send a driving signal according to the random delay duration.
[0083] Further, the delay component 13 also includes a second delay module 133, and the second delay module 133 is connected to the pseudo-random number generation module 131, the laser driving module 141 and the data transmission and communication module 12. The second delay module 133 is used to obtain the delay working mode indicated by the controller 11 through the data transmission and communication module 12, and generate a second delay duration based on the delay working mode. The delay working mode includes one of a random delay mode and a fixed delay mode. When the delay working mode is a fixed delay mode, the second delay module 133 is also used to generate a second delay duration based on the first delay duration and the target initial phase of the target laser. It can be seen from the above description that in this embodiment, the laser emitting component of the optical time domain reflectometer can delay a random delay time before the target laser is emitted, and the laser receiving component receives the reflected laser of the target laser according to the random delay time, and extracts the target signal in the reflected laser through a coherent accumulation scheme. Increasing the randomness of the optical pulse phase can effectively enhance the suppression of noise, improve the dynamic range and scanning consistency, and there is no need to introduce additional hardware resources. This technology is implemented within the existing system framework, does not require a large amount of computing resources when processing signals, and can be implemented on a relatively simple processor, which is conducive to reducing costs and realizing miniaturization of equipment.
[0084] The present invention also provides an intelligent device, the intelligent device comprising a processor and a memory. The processor is coupled to the memory. The memory stores a computer program, and the processor executes the computer program when working to implement the above method. The detailed steps can be found above and will not be repeated here.
[0085] The present invention also provides a computer-readable storage medium. The computer-readable storage medium stores at least one computer program, which is used to be executed by a processor to implement the above method. The detailed steps can be referred to above and will not be repeated here. In one embodiment, the computer-readable storage medium can be a storage chip, a hard disk, or a mobile hard disk or a USB flash drive, an optical disk, or other readable and writable storage tools in a terminal, or a server, etc.
[0086] Those skilled in the art can understand that all or part of the processes in the above-mentioned embodiment methods can be completed by instructing the relevant hardware through a computer program, and the program can be stored in a non-volatile computer-readable storage medium. When the program is executed, it can include the processes of the embodiments of the above-mentioned methods. Among them, any reference to memory, storage, database or other media used in the embodiments provided in this application can include non-volatile and / or volatile memory. Non-volatile memory may include read-only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM) or flash memory. Volatile memory may include random access memory (RAM) or external cache memory. As an illustration and not limitation, RAM is available in many forms, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), double data rate SDRAM (DDRSDRAM), enhanced SDRAM (ESDRAM), synchronous link (Synchlink) DRAM (SLDRAM), memory bus (Rambus) direct RAM (RDRAM), direct memory bus dynamic RAM (DRDRAM), and memory bus dynamic RAM (RDRAM).
[0087] The technical features of the above embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.
[0088] It should be understood that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. For those skilled in the art, the technical solutions described in the above embodiments can be modified, or some of the technical features therein can be replaced by equivalents; and all these modifications and replacements should fall within the scope of protection of the claims attached to the present invention.
Claims
1. A laser driving method for an optical time domain reflectometer, characterized in that: Applied to an optical time domain reflectometer, the optical time domain reflectometer comprises a laser transmitting component and a laser receiving component; The laser driving method of the optical time domain reflectometer comprises: Obtaining a random delay time length, and driving the laser emission component to emit a target laser based on the random delay time length; The random delay duration is notified to the laser receiving component, so that the laser receiving component can receive the reflected laser of the target laser according to the random delay duration, and obtain the target signal in the reflected laser by a coherent accumulation method.
2. The laser driving method of the optical time domain reflectometer according to claim 1, characterized in that: The step of obtaining the random delay duration includes: Obtain a pseudo-random number pattern, generate a pseudo-random number based on the pseudo-random number pattern, multiply the pseudo-random number by a clock period of the laser emitting component to obtain a first delay duration, and obtain the random delay duration based on the first delay duration.
3. The laser driving method of the optical time domain reflectometer according to claim 2, characterized in that: The step of obtaining the random delay duration also includes: Acquire a delay working mode, and generate a second delay duration based on the delay working mode, wherein the second delay duration does not exceed the clock cycle; The random delay duration is obtained according to the sum of the first delay duration and the second delay duration.
4. The laser driving method of the optical time domain reflectometer according to claim 3, characterized in that: The delay working mode includes one of a random delay mode and a fixed delay mode; When the delay working mode is the fixed delay mode, the step of generating a second delay duration based on the delay working mode includes: The second delay time is generated based on the first delay time and an initial phase of the target laser.
5. The laser driving method of an optical time domain reflectometer according to claim 1, characterized in that: The step of driving the laser emitting component to emit a target laser based on the random delay time length comprises: Acquire the frequency and pulse width information of the laser pulse of the target laser, and generate a delay control signal according to the random delay duration; A target pulse signal is generated based on the frequency and pulse width information and the delay control signal, and the laser emitting component is driven to emit the target laser based on the target pulse signal.
6. The laser driving method of an optical time domain reflectometer according to any one of claims 1 to 5, characterized in that: The step of enabling the laser receiving component to receive the target laser according to the random delay time comprises: The laser receiving component samples and caches the target laser according to the random delay time to generate a target signal; After the target signal is denoised, event recognition and positioning are performed, event information is acquired, and the event information is reported.
7. An optical time domain reflectometer, characterized in that: Used to implement the method described in any one of claims 1 to 6; The optical time domain reflectometer comprises: a controller, a data transmission and communication module connected to the controller, a delay component connected to the data transmission and communication module, a laser emitting component and a laser receiving component; The delay component is used to obtain a random delay duration according to an instruction of the controller, the laser emitting component is used to emit a target laser based on the random delay duration, and the laser receiving component is used to receive the target laser according to the random delay duration.
8. The optical time domain reflectometer according to claim 7, characterized in that: The delay component comprises: a pseudo-random number generation module and a first delay module connected to each other; The pseudo-random number generation module is connected to the data transmission and communication module, and is used to obtain a pseudo-random number pattern and generate a pseudo-random number based on the pseudo-random number pattern; The first delay module is used to multiply the pseudo-random number by the clock period of the laser emitting component to obtain a first delay duration.
9. The optical time domain reflectometer according to claim 8, characterized in that: The delay component also includes: A second delay module is connected to the data transmission and communication module, and is used to obtain a delay working mode, and generate a second delay duration based on the delay working mode, wherein the second delay duration does not exceed the clock cycle.
10. The optical time domain reflectometer according to claim 9, characterized in that: The second delay module is connected to the pseudo-random number generation module, and the delay working mode includes one of a random delay mode and a fixed delay mode; When the delay working mode is the fixed delay mode, the second delay module is further used to generate the second delay duration based on the first delay duration and the target initial phase of the target laser.