A transmission performance test method based on 100G Nrz direct modulation long-distance transmission optical signal

Abstract

The present application relates to the technical field of pre-diagnosis and health management, and specifically discloses a transmission performance test method for 100GNRZ direct modulation long-distance transmission optical signals, comprising the following steps: S1: configuring parameters of an OTN device, pre-setting test points, obtaining data received by the test points, calculating bit error rate and packet loss rate and selecting optimal test points; S2: setting rotating speed gears, adjusting according to the rotating speed gears, obtaining bit error rate and packet loss rate, obtaining the limit rotating speed of a polarization scrambler based on the bit error rate and packet loss rate of the optimal test points; S3: setting the rotating speed of the polarization scrambler to zero, making the rotating speed between two rotating speed gears cyclically jump, obtaining the jump interval at the end, and analyzing based on the limit rotating speed and the jump interval. Through the analysis of the bit error rate and the packet loss rate, the performance model of the device is constructed, so that the OTN device can always maintain an efficient and stable data transmission state in a complex and variable actual network environment.

Description

Technical Field

[0001] This invention relates to the field of pre-diagnosis and health management technology, specifically to a method for testing the transmission performance of 100GNRZ direct-modulation long-distance transmission optical signals. Background Technology

[0002] When 100G coherent fiber optic communication equipment transmits over power OPGW (Optical Open-Package Wiring), communication interruptions frequently occur during thunderstorms. The core reason for this problem is that lightning causes a rapid change in the polarization state (SOP) of the 100G coherent optical signal within the OPGW fiber. When the rate of change in SOP exceeds the tolerance of the 100G coherent receiver, the receiver's polarization tracking function fails, leading to momentary interruptions or bit errors in the OTN (Optical Transmission Network) system, ultimately affecting the secure and reliable transmission of information data. Therefore, there is an urgent need for a method to assess the transmission performance of 100G NRZ (Normally Inverted Light-Zone) direct-modulation long-distance optical signals under different environments, in order to quickly determine whether errors have occurred in the information data. Summary of the Invention

[0003] The purpose of this invention is to provide a method for testing the transmission performance of 100GNRZ direct-modulation long-distance optical signals, thereby solving the above-mentioned technical problems.

[0004] The objective of this invention can be achieved through the following technical solutions:

[0005] A method for testing the transmission performance of 100GNRZ direct-modulation long-distance optical signals includes the following steps:

[0006] S1: Set the OTN device to 100GNRZ direct modulation mode and adjust the optical power of the transmitter to AdBm, where A represents the preset optical power;

[0007] Pre-set test points D1, D2, ..., D on the optical fiber. i Among them, test point D i Distance L from the transmitter i =i×L s L s This represents the preset test distance, and i represents the test point D. i The corresponding subscript;

[0008] Set the initial rotation speed of the polarization scrambler to 0 Mrsd / s, and make the transmitter continuously send data. The data received by the test point is periodically acquired at a preset acquisition period T, and the bit error rate w and packet loss rate d of the data received by the test point are calculated. The optimal test point is selected based on the bit error rate w and packet loss rate d.

[0009] S2: Preset speed gear Z=λ×Z s Among them, Z sThe preset standard rotational speed is represented by λ, which represents the preset gradient coefficient, where λ = 1, 2, ... The rotational speed of the polarization scrambler is adjusted from low to high according to the rotational speed range Z, and the dwell time at each rotational speed range Z is preset to T. con The bit error rate W and packet loss rate D of the received data at the optimal test point are periodically obtained with a collection period T. Based on the optimal bit error rate W and packet loss rate D, the limiting rotational speed Z of the polarization scrambler is obtained. max ;

[0010] S3: Set the rotation speed of the polarization scrambler to zero, based on the limiting rotation speed Z. max Perform mutation testing, which includes the following steps:

[0011] Let the rotational speed of the polarization scrambler be between 0 Mrd / s and Z max The RPMs cyclically switch between two speed settings, Mrsd and s, with an interval of t seconds between each switch, where t represents a preset waiting time. The bit error rate W and packet loss rate D are obtained after each switch, and a preset bit error threshold W is set. max and packet loss threshold D max If W≥W max , D≥D max Let the transition interval be t+1 seconds, and repeat the above operation until W < W max , D < D max The time-stop transition is based on the limiting speed Z. max and the jump interval t at the end of the loop end Analyze the transmission performance.

[0012] As a further aspect of the present invention: in step S3, based on the limiting speed Z... max and the jump interval t at the end of the loop end Methods for analyzing transmission performance include:

[0013] The optimal distance LY between the test point and the transmitter is obtained, and no bit error or packet loss occurs when the optical signal based on 100GNRZ direct modulation is transmitted at a distance of LY without interference from the polarization meter.

[0014] When the transmission distance is LY, the 100GNRZ direct-modulation optical signal is transmitted at a speed below the limit Z of the polarization scrambler. max No errors or packet loss occur;

[0015] When bit errors and packet loss occur, and the transition interval is greater than or equal to t... end At that time, the bit error rate and packet loss rate of 100GNRZ direct modulation transmission optical signal data transmission were qualified.

[0016] As a further aspect of the present invention: in step S1, the method for selecting the optimal test point based on the bit error rate w and the packet loss rate d includes:

[0017] Test points with both bit error rate w and packet loss rate d being 0 are marked. From the marked test points, the test point that is farthest from the transmitter is selected and recorded as the optimal test point.

[0018] As a further aspect of the present invention: in step S1, it is ensured that the data sent by the sending end is the same each time.

[0019] As a further aspect of the present invention: in step S2, the limiting rotational speed Z of the polarization scrambling instrument is obtained based on the optimal test point bit error rate W and packet loss rate D. max The methods include:

[0020] When both the bit error rate W and the packet loss rate D are not zero, obtain the gradient coefficient λ1 at this time, and let the limiting rotational speed Z max =λ1×Z s .

[0021] As a further aspect of the present invention: in step S2, the acquisition period T is set to be less than the dwell time T. con .

[0022] As a further aspect of the present invention: in step S3, the rotational speed of the polarization scrambler is between 0 Mrd / s and Z. max The time consumed by switching between the two RPM gears, Mrsd / s, is ignored and not included in the switching interval t seconds.

[0023] As a further aspect of the present invention: in step S2, the maximum rotational speed of the polarization scrambler is obtained, and the rotational speed setting Z is always less than or equal to the maximum rotational speed of the polarization scrambler.

[0024] The beneficial effects of this invention are as follows: First, the OTN equipment is set to 100GNRZ direct modulation mode. This specific modulation mode ensures data transmission efficiency while minimizing signal distortion and interference. Simultaneously, the optical power at the transmitting end is set to AdBm. An appropriate optical power level affects the signal transmission quality and distance in the optical fiber; too high or too low power can lead to excessive attenuation, enhanced nonlinear effects, and other problems, thus affecting the performance of the entire system.

[0025] Next, multiple test points D1, D2, ..., D are set up on the fiber optic link used to transmit optical signals. i Test point D i Distance L from the transmitter i =i×L sBy setting up test points in this evenly distributed manner, fiber segments at different transmission distances can be covered, thereby capturing the changes in signal throughout the transmission process. The initial rotation speed is set to 0 Mrsd / s to verify the stability and reliability of the OTN equipment under different polarization conditions. Data received at each test point is acquired periodically at a preset acquisition period T. Based on the acquired data, the bit error rate w and packet loss rate d of the data received at each test point are calculated. The bit error rate w reflects the proportion of erroneous bits in the received data and is an important indicator for measuring the accuracy of data transmission; while the packet loss rate d reflects the loss of data packets during transmission and is directly related to data integrity and service continuity.

[0026] After obtaining the bit error rate and packet loss rate data for all test points, the optimal test point was selected. This optimal test point reflects the performance of the OTN device in a real-world operating environment, providing a strong basis for further optimizing network configuration and improving system reliability.

[0027] Then, the preset speed gear Z = λ × Z s By changing the value of λ, the rotational speed of the polarization scrambler can be gradually increased. This design aims to systematically explore the changes in the transmission performance of OTN equipment under different rotational speeds, in order to fully understand the equipment's adaptability to different disturbance environments.

[0028] The rotational speed of the polarization scrambler is adjusted sequentially from low to high according to the speed range Z. The dwell time is T at each specific speed range Z. con This ensures that the system has sufficient time to reach a stable state at the current speed, allowing the collected data to accurately reflect the transmission characteristics at that speed. During the dwell period, the bit error rate W and packet loss rate D of the received data at the optimal test point are periodically acquired at a preset acquisition period T. As the speed gear Z gradually increases, the above acquisition and calculation process is continuously repeated. The ultimate speed Z is then determined through comprehensive judgment. max The maximum speed limit Zmax is the maximum speed that the system can withstand while ensuring basic communication quality.

[0029] Next, a mutation test will be conducted. The specific procedure is as follows: First, the rotational speed of the polarization scrambler is set to zero, returning it to its initial stationary state. Based on the previously determined limiting rotational speed Z... max The rotational speed of the polarization scrambler is set at 0 Mrd / s and Z. maxThe system cyclically switches between two speed settings, Mrds / s. This switching mode simulates sudden interference or drastic changes that may occur in a real-world network environment, aiming to test the OTN device's adaptability and recovery capabilities to transient disturbances. A fixed interval t seconds is set between each switch, where t represents a preset waiting time, which provides the system with sufficient response time to adjust its state to cope with new speed conditions.

[0030] At the same time, set the bit error threshold W max and packet loss threshold D max This defines acceptable performance boundaries. During testing, the collected bit error rate W and packet loss rate D are compared and analyzed in real time with the corresponding thresholds. If W > W... max And D > D max The situation indicates that the system cannot maintain good transmission performance under the speed conditions after the speed jump. Therefore, the next jump interval is increased by 1 second, becoming t+1 seconds. The entire operation process is then repeated, including performing speed jumps again, data acquisition, and performance evaluation. By gradually extending the jump interval, the dynamic response characteristics and stability of the system at different time scales can be observed in detail.

[0031] Based on the limiting speed Z max and the final stable transition interval t end A comprehensive analysis of the transmission performance of OTN equipment is conducted: on the one hand, the limiting speed Z... max This intuitively reflects the maximum disturbance intensity that the equipment can withstand under static or quasi-static disturbance conditions, reflecting the equipment's static anti-interference capability; on the other hand, the jump interval t end This reveals the device's adaptive adjustment speed and state recovery efficiency in dynamic and volatile environments, demonstrating its dynamic response performance. By coupling these two key parameters, a performance model of the device can be constructed, thereby ensuring that OTN devices maintain efficient and stable data transmission in complex and ever-changing real-world network environments. Attached Figure Description

[0032] The invention will now be further described with reference to the accompanying drawings.

[0033] Figure 1 This is a flowchart illustrating a method for testing the transmission performance of a 100GNRZ direct-modulation long-distance optical signal according to the present invention. Detailed Implementation

[0034] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0035] Please see Figure 1 As shown, this invention provides a method for testing the transmission performance of 100GNRZ direct-modulation long-distance optical signals, comprising the following steps:

[0036] S1: Set the OTN device to 100GNRZ direct modulation mode and adjust the optical power of the transmitter to AdBm, where A represents the preset optical power;

[0037] Pre-set test points D1, D2, ..., D on the optical fiber. i Among them, test point D i Distance L from the transmitter i =i×L s L s This represents the preset test distance, and i represents the test point D. i The corresponding subscript;

[0038] Set the initial rotation speed of the polarization scrambler to 0 Mrsd / s, and make the transmitter continuously send data. The data received by the test point is periodically acquired at a preset acquisition period T, and the bit error rate w and packet loss rate d of the data received by the test point are calculated. The optimal test point is selected based on the bit error rate w and packet loss rate d.

[0039] S2: Preset speed gear Z=λ×Z s Among them, Z s The preset standard rotational speed is represented by λ, which represents the preset gradient coefficient, where λ = 1, 2, ... The rotational speed of the polarization scrambler is adjusted from low to high according to the rotational speed range Z, and the dwell time at each rotational speed range Z is preset to T. con The bit error rate W and packet loss rate D of the received data at the optimal test point are periodically obtained with a collection period T. Based on the optimal bit error rate W and packet loss rate D, the limiting rotational speed Z of the polarization scrambler is obtained. max ;

[0040] S3: Set the rotation speed of the polarization scrambler to zero, based on the limiting rotation speed Z. max Perform mutation testing, which includes the following steps:

[0041] Let the rotational speed of the polarization scrambler be between 0 Mrd / s and Z maxThe RPMs cyclically switch between two speed settings, Mrsd and s, with an interval of t seconds between each switch, where t represents a preset waiting time. The bit error rate W and packet loss rate D are obtained after each switch, and a preset bit error threshold W is set. max and packet loss threshold D max If W≥W max , D≥D max Let the transition interval be t+1 seconds, and repeat the above operation until W < W max , D < D max The time-stop transition is based on the limiting speed Z. max and the jump interval t at the end of the loop end Analyze the transmission performance.

[0042] It should be noted that the OTN equipment should first be set to 100GNRZ direct modulation mode. This modulation mode can ensure data transmission efficiency while minimizing signal distortion and interference, providing a stable signal foundation for subsequent testing. Simultaneously, the transmitting optical power needs to be set to a specific value in decibels and milliwatts. An appropriate optical power level directly determines the signal transmission quality and distance in the optical fiber. Too high or too low power may cause excessive signal attenuation, enhanced nonlinear effects, and ultimately adversely affect the overall system performance.

[0043] Next, multiple test points were set up on the optical fiber link used to transmit the optical signal. This uniformly distributed test point setup can cover optical fiber segments with different transmission distances, thereby fully capturing the signal variation characteristics throughout the entire transmission process. Subsequently, the initial rotational speed was set to 0 Mrsd / s. This initial rotational speed was used to verify the operational stability and reliability of the OTN equipment under different polarization conditions.

[0044] According to the preset collection cycle, data received at each test point is collected periodically. Based on the collected data, the bit error rate and packet loss rate of the received data at each test point are calculated. Among them, the bit error rate reflects the proportion of erroneous bits in the received data and is a core indicator for measuring the accuracy of data transmission; the packet loss rate reflects the loss of data packets during transmission and is directly related to data integrity and business continuity.

[0045] After acquiring the bit error rate and packet loss rate data for all test points, the optimal test point is selected. This optimal test point accurately reflects the true performance of the OTN device in its actual operating environment. Then, a preset speed range is established, and the speed of the scrambling device is gradually increased by changing the adjustment coefficient. The core objective is to systematically explore the transmission performance variation patterns of the OTN device under different speed conditions, thereby comprehensively understanding the device's adaptability to environments with varying disturbance intensities and providing data support for the stable operation of the device in complex scenarios.

[0046] During the specific testing process, the rotation speed of the polarization scrambler needs to be adjusted sequentially from low to high according to the preset speed settings. A fixed dwell time is maintained at each specific speed setting to ensure that the system has sufficient time to reach a stable operating state under the current speed conditions. This avoids deviations in the acquired data due to system instability, thus ensuring that the acquired data accurately reflects the transmission characteristics at that speed. During the dwell time at each speed setting, the bit error rate and packet loss rate of the received data at the optimal test point are continuously and periodically acquired according to the preset acquisition cycle, and the data is recorded and calculated in real time.

[0047] As the speed range gradually increases, the above data acquisition and calculation process is repeated until a significant degradation in system transmission performance is detected. Finally, by combining key indicators such as bit error rate and packet loss rate across all speed ranges, and considering the minimum requirements for basic system communication quality, the limiting speed is determined. This limiting speed refers to the maximum speed the equipment can withstand while ensuring the system can maintain basic communication quality, thus defining the boundary of the equipment's safe operating range.

[0048] Next, mutation testing was conducted to verify the performance of the OTN equipment under extreme dynamic disturbances. The operation procedure is as follows: First, the rotational speed of the polarization scrambler was reset to zero, restoring it to its initial stationary state. Based on the limiting rotational speed Z... max The rotational speed of the polarization scrambler is controlled between 0 Mrsd / s and Z. max The device cycles between two speed settings, Mrsd / s, to simulate sudden interference that may occur in a real network environment. Its core purpose is to comprehensively test the OTN equipment's ability to quickly adapt to and recover from instantaneous strong disturbances.

[0049] Setting an interval of t seconds provides a buffer period for the system, allowing it to adjust its state through an internal adaptive mechanism to cope with the new speed conditions after the jump, ensuring that the transition of the system state during the test is more in line with the actual operating logic.

[0050] At the same time, a clear error threshold W needs to be set in advance. max and packet loss threshold D max When the bit error rate W does not exceed W max And the packet loss rate D exceeds D max When the system transmission performance is deemed to be outside the normal range, the bit error rate W and packet loss rate D at the optimal test point are compared and analyzed with the corresponding thresholds. If W ≥ W... max , D≥D maxIf the performance index remains within the threshold range, the next jump interval will be extended by 1 second, i.e., updated to t+1 seconds; if the performance index remains within the threshold range, the interval t will remain unchanged. This process is then repeated, including re-executing the speed jump, periodically collecting data, and performing performance evaluation and interval adjustment. By gradually extending the jump interval, the dynamic response characteristics of the system at different time scales can be observed, capturing the critical time threshold required for the system to recover from performance degradation.

[0051] Based on the limiting speed Z max and the final stable transition interval t end A comprehensive analysis of the transmission performance of OTN equipment is conducted: on the one hand, the limiting speed Z... max This intuitively reflects the maximum disturbance intensity that the equipment can withstand under static or quasi-static disturbance conditions, reflecting the equipment's static anti-interference capability; on the other hand, the jump interval t end This reveals the device's adaptive adjustment speed and state recovery efficiency in dynamic and volatile environments, demonstrating its dynamic response performance. By coupling these two key parameters, a performance model of the device can be constructed, thereby ensuring that OTN devices maintain efficient and stable data transmission in complex and ever-changing real-world network environments.

[0052] In another preferred embodiment of the present invention, based on the limiting speed Z max and the jump interval t at the end of the loop end Methods for analyzing transmission performance include:

[0053] The optimal distance LY between the test point and the transmitter is obtained, and no bit error or packet loss occurs when the optical signal based on 100GNRZ direct modulation is transmitted at a distance of LY without interference from the polarization meter.

[0054] When the transmission distance is LY, the 100GNRZ direct-modulation optical signal is transmitted at a speed below the limit Z of the polarization scrambler. max No errors or packet loss occur;

[0055] When bit errors and packet loss occur, and the transition interval is greater than or equal to t... end At that time, the bit error rate and packet loss rate of 100GNRZ direct modulation transmission optical signal data transmission were qualified.

[0056] It is worth noting that, firstly, benchmark verification was conducted using the distance LY between the optimal test point and the transmitter. In an ideal environment without polarization interference, for optical signals transmitted in 100GNRZ direct modulation mode, at a transmission distance of LY, the state of complete error rate and packet loss was ensured as a reference. This verified the inherent transmission capability of the optical signal at this transmission distance in a static, undisturbed scenario, providing a baseline for subsequent performance comparisons after introducing disturbances.

[0057] Secondly, with the limiting speed Z max The core focus is on analyzing the impact of disturbance intensity on transmission performance. When the transmission distance is fixed at LY, the 100GNRZ directly modulated optical signal is observed when the polarization scrambler rotation speed is below Z. max If the signal consistently exhibits bit errors and packet loss at this time, it indicates that the device can reliably withstand disturbances below the limit intensity at this transmission distance. When the disturbance intensity does not exceed this threshold, the system can maintain basic communication quality.

[0058] Finally, combining the jump interval t end The performance recovery capability under dynamic mutation scenarios is evaluated. When bit errors or packet loss occur during the test, if the transition interval is greater than or equal to t... end At this point, the bit error rate and packet loss rate of the 100GNRZ direct-modulated optical signal can fall back to the acceptable range, indicating that t end It is the critical time required for the system to recover stability after a dynamic mutation.

[0059] In summary, the three key factors of transmission distance, disturbance intensity, and dynamic recovery time are deeply correlated with performance indicators, verifying the limiting speed Z. max and transition interval t end The practical significance of this is that it provides a quantitative basis for formulating disturbance protection strategies in actual networks.

[0060] In another preferred embodiment of the present invention, the method for selecting the optimal test point based on the bit error rate w and the packet loss rate d includes:

[0061] Test points with both bit error rate w and packet loss rate d being 0 are marked. From the marked test points, the test point that is farthest from the transmitter is selected and recorded as the optimal test point.

[0062] Understandably, test points with both a bit error rate and packet loss rate of 0 are first marked, representing a state of error-free transmission performance. Then, the point furthest from the transmitter is selected as the optimal test point. This approach ensures both the accuracy and integrity of data transmission while prioritizing the point with the longest transmission distance, providing a more comprehensive reflection of the device's stable performance in long-distance transmission under real-world conditions and offering a reliable reference for subsequent testing and optimization.

[0063] In another preferred embodiment of the present invention, it is ensured that the data sent by the sending end is the same each time.

[0064] It is important to ensure that the data sent by the sending end is completely consistent each time, so as to avoid introducing additional variables due to differences in data content, eliminate the interference of differences in the data itself on the test results, and make the analysis conclusions more accurate and reliable.

[0065] In another preferred embodiment of the present invention, the limiting rotational speed Z of the polarization scrambling instrument is obtained based on the optimal test point bit error rate W and packet loss rate D. max The methods include:

[0066] When both the bit error rate W and the packet loss rate D are not zero, obtain the gradient coefficient λ1 at this time, and let the limiting rotational speed Z max =λ1×Z s .

[0067] It should be noted that, based on the optimal test point, when both the bit error rate W and the packet loss rate D are detected to be non-zero, the gradient coefficient λ1 at this point is recorded, and the limiting rotational speed Z is obtained. max Define the maximum rotational speed that the device can withstand while ensuring basic communication quality.

[0068] In another preferred embodiment of the present invention, the acquisition period T is set to be less than the dwell time T. con .

[0069] Understandably, the significance lies in ensuring that multiple data acquisitions can be completed within the stable dwell period of each RPM gear. This allows for the acquisition of multiple sets of bit error rate and packet loss rate data, avoiding the random errors of a single acquisition and making the data more representative.

[0070] In another preferred embodiment of the invention, the rotational speed of the polarization scrambler is between 0 Mrd / s and Z. max The time consumed by switching between the two RPM gears, Mrsd / s, is ignored and not included in the switching interval t seconds.

[0071] It is important to ensure that the transition interval t accurately reflects the system's response and recovery time. After eliminating the time-consuming interference of the transition operation itself, subsequent adjustments to t due to performance degradation can be clearly attributed to the system's adaptability to speed changes, rather than the operation time itself. This allows for a more precise understanding of t. end The determination is more accurate, providing a reliable time benchmark for analyzing the dynamic recovery capability of equipment.

[0072] In another preferred embodiment of the present invention, the maximum rotational speed of the polarization scrambler is obtained, and the rotational speed setting Z is always less than or equal to the maximum rotational speed of the polarization scrambler.

[0073] It is worth noting that if the speed setting exceeds the maximum speed, the motor and transmission components inside the polarization scrambler will be in an overloaded state for a long time, which will accelerate mechanical wear and may cause malfunctions such as overheating and jamming of components, shorten the service life of the equipment, or even cause irreversible hardware damage.

[0074] Furthermore, operating at speeds exceeding the maximum speed may cause severe vibrations and abnormal noises in the equipment, which not only affects its own stability but may also interfere with the normal operation of surrounding related equipment. At the same time, there is a safety hazard of equipment failure due to component failure. Ensuring that the speed does not exceed the limit can effectively avoid such risks.

[0075] The foregoing has provided a detailed description of one embodiment of the present invention, but this description is merely a preferred embodiment and should not be construed as limiting the scope of the invention. All equivalent variations and modifications made within the scope of the present invention should still fall within the scope of the present invention.

Claims

1. A method for testing the transmission performance of 100GNRZ direct-modulation long-distance optical signals, characterized in that, Includes the following steps: S1: Set the OTN device to 100GNRZ direct modulation mode and adjust the optical power of the transmitter to AdBm, where A represents the preset optical power; Pre-set test points D1, D2, ..., D on the optical fiber. i Among them, test point D i Distance L from the transmitter i =i×L s L s This represents the preset test distance, and i represents the test point D. i The corresponding subscript; Set the initial rotation speed of the polarization scrambler to 0 Mrsd / s, and make the transmitter continuously send data. The data received by the test point is periodically acquired at a preset acquisition period T, and the bit error rate w and packet loss rate d of the data received by the test point are calculated. The optimal test point is selected based on the bit error rate w and packet loss rate d. S2: Preset speed gear Z=λ×Z s Among them, Z s The preset standard rotational speed is represented by λ, which represents the preset gradient coefficient, where λ = 1, 2, ... The rotational speed of the polarization scrambler is adjusted from low to high according to the rotational speed range Z, and the dwell time at each rotational speed range Z is preset to T. con The bit error rate W and packet loss rate D of the received data at the optimal test point are periodically obtained with a collection period T. Based on the optimal bit error rate W and packet loss rate D, the limiting rotational speed Z of the polarization scrambler is obtained. max ; S3: Set the rotation speed of the polarization scrambler to zero, based on the limiting rotation speed Z. max Perform mutation testing, which includes the following steps: Let the rotational speed of the polarization scrambler be between 0 Mrd / s and Z max The RPMs cyclically switch between two speed settings, Mrsd and s, with an interval of t seconds between each switch, where t represents a preset waiting time. The bit error rate W and packet loss rate D are obtained after each switch, and a preset bit error threshold W is set. max and packet loss threshold D max If W≥W max , D≥D max Let the transition interval be t+1 seconds, and repeat the above operation until W < W max , D < D max The time-stop transition is based on the limiting speed Z. max and the jump interval t at the end of the loop end Analyze the transmission performance.

2. The method for testing the transmission performance of a 100G NRZ direct-modulation long-distance optical signal according to claim 1, characterized in that, In step S3, based on the limiting speed Z max and the jump interval t at the end of the loop end Methods for analyzing transmission performance include: The optimal distance LY between the test point and the transmitter is obtained, and no bit error or packet loss occurs when the optical signal based on 100GNRZ direct modulation is transmitted at a distance of LY without interference from the polarization meter. When the transmission distance is LY, the 100GNRZ direct-modulation optical signal is transmitted at a speed below the limit Z of the polarization scrambler. max No errors or packet loss occur; When bit errors and packet loss occur, and the transition interval is greater than or equal to t... end At that time, the bit error rate and packet loss rate of 100GNRZ direct modulation transmission optical signal data transmission were qualified.

3. The method for testing the transmission performance of a 100G NRZ direct-modulation long-distance optical signal according to claim 1, characterized in that, In step S1, the method for selecting the optimal test point based on the bit error rate w and the packet loss rate d includes: Test points with both bit error rate w and packet loss rate d being 0 are marked. From the marked test points, the test point that is farthest from the transmitter is selected and recorded as the optimal test point.

4. The method for testing the transmission performance of a 100G NRZ direct-modulation long-distance optical signal according to claim 1, characterized in that, In step S1, it is ensured that the data sent by the sending end is the same each time.

5. The method for testing the transmission performance of a 100G NRZ direct-modulation long-distance optical signal according to claim 1, characterized in that, In step S2, the limiting rotational speed Z of the polarization scrambler is obtained based on the optimal test point bit error rate W and packet loss rate D. max The methods include: When both the bit error rate W and the packet loss rate D are not zero, obtain the gradient coefficient λ1 at this time, and let the limiting rotational speed Z max =λ1×Z s .

6. The method for testing the transmission performance of a 100G NRZ direct-modulation long-distance optical signal according to claim 1, characterized in that, In step S2, the acquisition period T is set to be less than the dwell time T. con .

7. The method for testing the transmission performance of a 100G NRZ direct-modulation long-distance optical signal according to claim 1, characterized in that, In step S3, the rotational speed of the polarization scrambler is between 0 Mrd / s and Z. max The time consumed by switching between the two RPM gears, Mrsd / s, is ignored and not included in the switching interval t seconds.

8. The method for testing the transmission performance of a 100G NRZ direct-modulation long-distance optical signal according to claim 1, characterized in that, In step S2, the maximum speed of the polarization scrambler is obtained, and the speed setting Z is always less than or equal to the maximum speed of the polarization scrambler.

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