WO2023142939A1 - Procédé de test de cohérence et appareil associé - Google Patents

Procédé de test de cohérence et appareil associé Download PDF

Info

Publication number
WO2023142939A1
WO2023142939A1 PCT/CN2023/070628 CN2023070628W WO2023142939A1 WO 2023142939 A1 WO2023142939 A1 WO 2023142939A1 CN 2023070628 W CN2023070628 W CN 2023070628W WO 2023142939 A1 WO2023142939 A1 WO 2023142939A1
Authority
WO
WIPO (PCT)
Prior art keywords
test
sequence
equalization
optical
signal sequence
Prior art date
Application number
PCT/CN2023/070628
Other languages
English (en)
Chinese (zh)
Inventor
林友熙
郑建宇
陈健
张乐伟
Original Assignee
华为技术有限公司
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 华为技术有限公司 filed Critical 华为技术有限公司
Publication of WO2023142939A1 publication Critical patent/WO2023142939A1/fr

Links

Images

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B10/00—Transmission systems employing electromagnetic waves other than radio-waves, e.g. infrared, visible or ultraviolet light, or employing corpuscular radiation, e.g. quantum communication
    • H04B10/07—Arrangements for monitoring or testing transmission systems; Arrangements for fault measurement of transmission systems
    • H04B10/075—Arrangements for monitoring or testing transmission systems; Arrangements for fault measurement of transmission systems using an in-service signal
    • H04B10/079—Arrangements for monitoring or testing transmission systems; Arrangements for fault measurement of transmission systems using an in-service signal using measurements of the data signal
    • H04B10/0799—Monitoring line transmitter or line receiver equipment
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B10/00—Transmission systems employing electromagnetic waves other than radio-waves, e.g. infrared, visible or ultraviolet light, or employing corpuscular radiation, e.g. quantum communication
    • H04B10/07—Arrangements for monitoring or testing transmission systems; Arrangements for fault measurement of transmission systems
    • H04B10/075—Arrangements for monitoring or testing transmission systems; Arrangements for fault measurement of transmission systems using an in-service signal
    • H04B10/079—Arrangements for monitoring or testing transmission systems; Arrangements for fault measurement of transmission systems using an in-service signal using measurements of the data signal
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B10/00—Transmission systems employing electromagnetic waves other than radio-waves, e.g. infrared, visible or ultraviolet light, or employing corpuscular radiation, e.g. quantum communication
    • H04B10/07—Arrangements for monitoring or testing transmission systems; Arrangements for fault measurement of transmission systems
    • H04B10/075—Arrangements for monitoring or testing transmission systems; Arrangements for fault measurement of transmission systems using an in-service signal
    • H04B10/079—Arrangements for monitoring or testing transmission systems; Arrangements for fault measurement of transmission systems using an in-service signal using measurements of the data signal
    • H04B10/0795—Performance monitoring; Measurement of transmission parameters

Definitions

  • the embodiments of the present application relate to communication technologies, and in particular, to a conformance testing method and related devices.
  • Physical layer devices in a data center network include components such as transmitters, optical fibers, and receivers.
  • DCN data center network
  • G gigabit
  • NRZ non-return-to-zero
  • PAM4 pulse amplitude modulation
  • TDECQ transmitter and dispersion eye closure quaternary
  • FFE feedforward equalizer
  • the present application provides a conformance testing method and related devices, which are used to solve the problem of how to determine whether the optical signal transmitted by the transmitter can meet the use requirements of the receiver in a high signal rate scenario.
  • the first aspect of the present application provides a conformance testing method, which is characterized in that the method includes: collecting the signal sequence of the optical signal received by the optical receiver, and the optical signal is transmitted by the optical transmitter using a four-level pulse amplitude
  • the modulation mode modulation test sequence is generated; the test sequence is obtained; the signal sequence is equalized and compensated according to the test sequence; the equalization coefficient of the signal sequence obtained according to the equalization compensation is used to synthesize the test eye diagram; according to the test
  • the eye diagram and the noise enhancement coefficient corresponding to the equalization compensation calculate the value of the test parameter; if the value of the test parameter is less than or equal to the first threshold, it is determined that the conformance test of the optical signal is passed.
  • the consistency test method uses a known test sequence to perform equalization compensation on the collected signal sequence, synthesizes a test eye diagram based on the equalization coefficient of the equalization compensation, and updates the noise enhancement coefficient based on the test eye diagram and the equalization compensation
  • the value of the test parameter is calculated, and it is judged whether the consistency test of the optical signal passes according to whether the value of the test parameter is less than or equal to the threshold.
  • Using a known test sequence to perform equalization compensation on the collected signal sequence can improve the equalization compensation effect, increase the acceptable additional noise margin of the system, improve the numerical accuracy of the TDECQ test, optimize the test performance, and meet the needs of optical transmitters in high signal rate scenarios. conformance testing requirements.
  • the optical signal consistency test passes indicating the consistency of the optical transmitter The test passes.
  • the optical signal is transmitted by the optical transmitter when the relative intensity noise is the largest, it can be determined that the optical receiver uses In this equalization method, whether the conformance test of the optical transmitter adopting the PAM4 mode passes.
  • the method further includes: calculating the number of consecutive bit errors according to the test eye diagram and the signal sequence; if the value of the test parameter is less than or equal to The first threshold, then determining that the conformance test of the optical signal has passed includes: if the value of the test parameter is less than or equal to the first threshold, and the number of consecutive bit errors is less than or equal to the second threshold, then determining the The consistency test of the optical signal is passed.
  • the consistency test method provided by this application can also judge the number of consecutive bit errors in the system in order to accurately evaluate whether the consistency test of the optical signal is passed.
  • the number of consecutive bit errors is less than or equal to the second threshold, the It is judged whether the value of the test parameter is less than or equal to the first threshold, and if the two conditions are met, it is judged that the consistency test of the optical signal has passed, which further improves the accuracy of the implementation of the scheme.
  • the equalizing and compensating the signal sequence according to the test sequence includes: performing feedforward adaptive equalization on the signal sequence to obtain a first equalized signal sequence and a first an equalization coefficient; performing feed-forward adaptive equalization on the first equalized signal sequence according to the test sequence to obtain a second equalization coefficient.
  • the equalization compensation includes feedforward adaptive equalization, and the newly added equalization compensation for the first equalized signal sequence obtained by the feedforward adaptive equalization according to the test sequence, the first equalization coefficient and the second equalization coefficient
  • the two equalization coefficients are used to synthesize test eye diagrams.
  • This equalization compensation step improves the equalization compensation effect, thereby improving the acceptable additional noise margin of the system, improving the accuracy of test parameters, and optimizing test performance.
  • an equalization coefficient of the signal sequence is determined according to the first equalization coefficient and the second equalization coefficient; and the test eye diagram is synthesized according to the equalization coefficient of the signal sequence.
  • the consistency testing method provided by the present application obtains the equalization system of the signal sequence based on the first equalization coefficient and the second equalization coefficient, and is used for synthesizing the eye pattern, thereby improving the equalization effect.
  • calculating the value of the test parameter according to the test eye diagram and the noise enhancement coefficient corresponding to the equalization compensation includes: according to the test eye diagram and the noise enhancement coefficient, determining the standard deviation of the maximum additive noise that the optical transmitter can support when reaching the target bit error rate; according to the standard deviation of the maximum additive noise that the optical transmitter can support when reaching the target bit error rate, Determine the value of the test parameter.
  • the consistency test method provided by this application when calculating the value of the test parameter, can first determine the standard deviation of the maximum additive noise that the optical transmitter can support when the target bit error rate is reached, and then further determine the value of the test parameter, A specific implementation method for obtaining test parameter values is provided, which enhances the realizability of the scheme.
  • determining the value of the test parameter includes:
  • OMA optical modulation amplitude of the test eye pattern
  • Qt is the Q value of the test sequence waveform
  • ⁇ G is the standard deviation of the maximum additive noise
  • ⁇ s is the standard deviation of the optical receiver noise
  • Ceq Be the noise enhancement coefficient
  • N (f) is a noise density function
  • Heq (f) is the frequency response function of the first equalization coefficient
  • the consistency test method provided by this application provides specific calculation formulas for test parameters. It is worth noting that, compared with the calculation formulas of the existing consistency test, the calculation formula of the noise enhancement coefficient in this scheme takes into account the change of the equalization unit There are also adaptive improvements, which make the overall calculation process of this scheme self-consistent and easy to implement.
  • the second aspect of the present application provides a conformance test device, including: a collection unit, used to collect the signal sequence of the optical signal received by the optical receiver, the optical signal is modulated by the optical transmitter using four-level pulse amplitude PAM4 Mode modulation test sequence generation; acquisition unit, used to obtain the test sequence; processing unit, used to perform equalization compensation on the signal sequence according to the test sequence, and obtain the equalization of the signal sequence according to the equalization compensation
  • the coefficient synthesis test eye diagram the calculation unit is used to calculate the value of the test parameter according to the noise enhancement coefficient corresponding to the test eye diagram and the equalization compensation; the determination unit is used for when the value of the test parameter is less than or When it is equal to the first threshold, it is determined that the consistency test of the optical signal passes.
  • the optical signal consistency test passes indicating the consistency of the optical transmitter The test passes.
  • the calculation unit is further configured to: calculate the number of consecutive bit errors according to the test eye diagram and the signal sequence; the determination unit is specifically configured to: in the When the value of the test parameter is less than or equal to the first threshold and the number of consecutive bit errors is less than or equal to the second threshold, it is determined that the consistency test of the optical signal is passed.
  • the processing unit is specifically configured to: perform feedforward adaptive equalization on the signal sequence to obtain a first equalized signal sequence and a first equalization coefficient;
  • the first equalized signal sequence is subjected to feedforward adaptive equalization to obtain second equalization coefficients.
  • the processing unit is specifically configured to: determine the equalization coefficient of the signal sequence according to the first equalization coefficient and the second equalization coefficient; coefficients to synthesize the test eye diagram.
  • the calculation unit is specifically configured to: determine the maximum BER that the optical transmitter can support when reaching the target bit error rate according to the test eye diagram and the noise enhancement coefficient.
  • the standard deviation of additive noise according to the standard deviation of the maximum additive noise that the optical transmitter can support when the target bit error rate is reached, the value of the test parameter is determined.
  • the calculation unit is specifically configured to: calculate the test parameter T according to the following formula:
  • OMA optical modulation amplitude of the test eye diagram
  • Qt is the Q value of the test sequence waveform
  • ⁇ G is the standard deviation of the maximum additive noise
  • ⁇ S is the standard deviation of the optical receiver noise
  • Ceq Be the noise enhancement coefficient
  • N (f) is a noise density function
  • Heq (f) is the frequency response function of the first equalization coefficient
  • the length of the signal sequence is greater than or equal to the length of the test sequence; the processing unit is specifically configured to perform sequence alignment on the signal sequence according to the test sequence , performing the equalization compensation on the signal sequence after sequence alignment.
  • the third aspect of the present application provides a conformance testing device, which is characterized in that it includes: one or more processors and memory; wherein, computer-readable instructions are stored in the memory; the one or more processors Reading the computer-readable instructions enables the conformance testing device to execute the method described in any one of the above-mentioned first aspect and various possible implementation manners.
  • the fourth aspect of the present application provides a computer program product containing instructions, which is characterized in that, when it is run on a computer, the computer executes the program described in any one of the above-mentioned first aspect and various possible implementation manners. described method.
  • the fifth aspect of the present application provides a computer-readable storage medium, including instructions, which is characterized in that, when the instructions are run on the computer, the computer executes any one of the above-mentioned first aspect and various possible implementation manners. method described in the item.
  • the sixth aspect of the present application provides a chip, including a processor.
  • the processor is used to read and execute the computer program stored in the memory, so as to execute the method in any possible implementation manner of any aspect above.
  • the chip includes a memory, and the memory and the processor are connected to the memory through a circuit or wires.
  • the chip further includes a communication interface, and the processor is connected to the communication interface.
  • the communication interface is used to receive data and/or information to be processed, and the processor obtains the data and/or information from the communication interface, processes the data and/or information, and outputs the processing result through the communication interface.
  • the communication interface may be an input-output interface.
  • the technical effect brought by any one of the second, third, fourth, fifth, or sixth aspects can refer to the technical effect brought by the corresponding implementation in the first aspect, here I won't repeat them here.
  • the present application provides a conformance testing method, device and storage medium, which are used to solve the problem of how to determine whether the optical signal transmitted by the transmitter can meet the use requirements of the receiver in a high signal rate scenario.
  • the method performs equalization compensation on the collected signal sequence through the test sequence, which can improve the equalization compensation effect, increase the acceptable additional noise margin of the system, improve the numerical accuracy of the test TDECQ, and optimize the test performance.
  • Fig. 1 is a schematic diagram of a conformance testing system
  • Fig. 2 is a schematic diagram of a test eye diagram
  • Fig. 3 is a structural schematic diagram of a reference equalizer
  • FIG. 4 is a schematic diagram of the system architecture of the conformance testing system in the embodiment of the present application.
  • FIG. 5 is another schematic diagram of the system architecture of the conformance testing system in the embodiment of the present application.
  • FIG. 6 is a schematic flow chart of a consistency testing method provided in an embodiment of the present application.
  • FIG. 7 is a schematic diagram of a reference equalizer provided in an embodiment of the present application.
  • FIG. 8 is a schematic flowchart of another consistency testing method provided in the embodiment of the present application.
  • FIG. 9 is a schematic diagram of an embodiment of a consistency testing method provided in an embodiment of the present application.
  • FIG. 10 is a schematic diagram of a system architecture of a receiving end in an embodiment of the present application.
  • FIG. 11 is a schematic diagram of a calculation process of a receiving end in an embodiment of the present application.
  • FIG. 12 is a schematic structural diagram of a conformance testing device provided in an embodiment of the present application.
  • FIG. 13 is a schematic structural diagram of another conformance testing device provided in an embodiment of the present application.
  • Embodiments of the present application provide a conformance testing method and a related device, which are used to solve the problem of how to determine whether the optical signal transmitted by the transmitter can meet the use requirements of the receiver in a high signal rate scenario.
  • TEC Transmitter and dispersion eye closure
  • this indicator is defined as transmitter dispersion penalty (transmitter and dispersion penalty, TDP); in the 100G Ethernet IEEE 802.3bm standard, this indicator is defined as TDEC; and for 200G/400G Ethernet In the IEEE 802.3bs standard, the indicator is TDECQ.
  • FFE is a commonly used linear equalizer that corrects voltage levels by removing the effects of intersymbol interference.
  • a reference equalizer (reference equalizer) is required.
  • the reference equalizer specified in the existing standard It is a FFE equalizer with 5 taps (tap)/T interval (spaced).
  • T is defined as the reciprocal of the signal baud rate, that is, 1/fs, fs is the baud rate of the signal/waveform, equalized
  • T is defined as the reciprocal of the signal baud rate, that is, 1/fs, fs is the baud rate of the signal/waveform, equalized
  • the specific equalization coefficients of the filter need to be determined according to the input signal by an adaptive algorithm.
  • the consistency test method in this application is a method for testing an optical transmitter based on a standard reference receiver.
  • FIG. 1 is a schematic diagram of a conformance testing system. As shown in Figure 1, the test system can include:
  • Optical transmitter optical fiber, O/E converter, clock recovery unit (CRU), oscilloscope, and reference equalizer.
  • the optical transmitter is located at the sending end, and the receiving end is a standard reference receiver, including: a photoelectric converter, a clock recovery unit and an oscilloscope.
  • the test system is used to implement the TDECQ calculation method including the reference equalizer.
  • the optical transmitter transmits an optical signal, and the optical signal is transmitted to the receiving end through an optical fiber.
  • the optical signal sent by the transmitter can also be transmitted to the receiving end through the polarization rotator through the optical fiber. Therefore, through this test system, the consistency of the optical signal sent by the optical transmitter under different relative intensity noises can be tested .
  • the optical-to-electrical converter, the clock recovery unit and the reference equalizer are used to simulate the behavior of an optical receiver (that is, an optical receiver that receives optical signals in an equalized manner).
  • the photoelectric converter is used to convert the received optical signal into an electrical signal.
  • the clock recovery unit is used to extract the clock of the optical signal.
  • the oscilloscope is used to collect the waveform of the electrical signal processed by the photoelectric converter in the form of sequence according to the clock extracted by the clock recovery unit.
  • a reference equalizer including an analysis software module, for equalizing the acquired sequence. Through the collected electrical signal sequence or the compensated electrical signal sequence, optical parameters such as optical modulation amplitude (optical modulation amplitude, OMA) and average optical power of the optical signal emitted by the optical transmitter can be calculated.
  • optical modulation amplitude optical modulation amplitude
  • OMA optical modulation amplitude
  • photoelectric converter, clock recovery unit and reference equalizer may exist independently of the oscilloscope, or may be integrated in the oscilloscope.
  • the photoelectric converter, clock recovery unit and reference equalizer in the test system shown in Figure 1 all exist independently of the oscilloscope.
  • the optical signal emitted by the optical transmitter can be collected by the above test system first. Specifically: the tester turns on the optical transmitter, and loads a test signal sequence (that is, a test sequence) of a preset waveform into the optical transmitter.
  • the test sequence mentioned here may be a sequence with a fixed length. The sequence is random enough to simulate the data transmitted in a real transmission scenario.
  • the optical transmitter uses PAM4 to modulate the test sequence to generate an optical signal, and sends the optical signal to the optical link.
  • Testers can rotate the polarization rotator to change the polarization direction of the optical signal according to the test requirements.
  • the oscilloscope at the receiving end can collect the signal sequence in the received optical signal. Since the length of the test sequence is fixed, according to the length of the test sequence, the complete waveform (ie, the signal sequence) of the test sequence can be collected from the optical signal by an oscilloscope. After the signal sequence in the optical signal is collected by the oscilloscope, the signal sequence can be processed and analyzed to determine whether the optical signal emitted by the optical transmitter to be tested can meet the requirements of the standard reference receiver, thereby judging the optical emission. Whether the conformance test of the machine passes.
  • FIG. 3 is a schematic structural diagram of a reference equalizer, and the reference equalizer is a 5 tap/T spaced FFE equalizer.
  • the test eye diagram is used to obtain the value of OMA, calculate the noise enhancement coefficient, and further calculate the value of TDECQ to judge the performance of the optical transmitter.
  • the embodiment of the present application provides a conformance testing method, which can test the optical signal transmitted by the transmitter in a high signal rate scenario, so as to determine whether the optical signal can meet the use requirements of the receiver.
  • the reference equalizer is mainly improved, and the reference equalizer can use a known test sequence to equalize and compensate the collected signal sequence. Since sequence equalization is adopted in this method, that is, the receiving end knows the test sequence modulated by the optical transmitter using PAM4 mode, and performs equalization processing according to the known test sequence.
  • Figure 4 and Figure 5 are system architecture diagrams of the consistency testing system in the embodiment of the present application.
  • the consistency testing system of the present application adds a sequence storage unit at the receiving end, the The sequence storage unit is used to store known test sequences, and send the test sequences to the oscilloscope for sequence alignment and equalization.
  • the sequence storage unit receives the test sequence sent by the sending end (as shown in FIG. 4 ), or, the sequence storage unit sends the test sequence to the sending end (as shown in FIG. 5 ).
  • an embodiment of the present application provides a conformance testing method, and the execution subject of the method is a conformance testing device.
  • the conformance testing device may specifically be a processing device with a processing function, for example, a computer, a server, etc. independent of the test system, or an oscilloscope in the test system.
  • the conformance test device is a processing device independent of the test system
  • the above-mentioned reference equalizer may exist independently in the test system, or may be integrated in an oscilloscope of the test system, or may be integrated in the processing device.
  • the above-mentioned reference equalizer when the above-mentioned reference equalizer is integrated in a processing device (for example, a processing device independent of the test system, or an oscilloscope in the test system), the above-mentioned reference equalizer can be implemented by means of hardware and/or software accomplish.
  • the above-mentioned reference equalizer can be realized by constructing a reference equalizer model in a processing device. Specifically, there is no limitation here.
  • the method includes steps 601-606.
  • the optical signal is an optical signal generated by modulating the test sequence by the optical transmitter in a PAM4 manner, and the optical signal is transmitted to the receiving end through an optical link.
  • the consistency testing device acquires the test sequence and stores it in the sequence storage unit. It should be noted that the sequence storage unit may be an independent device or a part of the consistency testing device, which is not limited here. Optionally, the consistency testing device receives the test sequence sent by the sending end; or, the receiving end sends the test sequence stored in the sequence storage unit to the sending end, which is not limited here.
  • the test sequence is used for the optical transmitter to modulate the test sequence in a PAM4 manner to generate an optical signal, and transmit the optical signal to the receiving end through an optical link.
  • the consistency testing device may perform sequence alignment on the signal sequence according to the test sequence, and the sequence-aligned signal sequence is used for subsequent equalization compensation.
  • the consistency testing device performs equalization compensation on the signal sequence through a reference equalizer, specifically, performs equalization compensation through a known test sequence.
  • the conformance testing device performs feedforward adaptive equalization on the signal sequence to obtain the first equalized signal sequence and the first equalization coefficient; performs feedforward on the first equalized signal sequence according to the test sequence Adaptive equalization to obtain a second equalization coefficient. Then, the consistency testing device determines the equalization coefficient of the signal sequence according to the first equalization coefficient and the second equalization coefficient.
  • the reference equalizer includes two parts (part A and part B), wherein part A is a feed-forward equalizer FFE.
  • Part B is the feed-forward adaptive equalizer that uses the test sequence and the first equalized signal sequence output by FFE as input. Its structure is the same as that of FFE. The difference is that the test sequence and the first equalized signal sequence are input.
  • Known test sequences can be used for data judgment, and a function similar to decision feedback equalizer (DFE) can be realized.
  • part B of the reference equalization removes the feedback branch, avoids the complicated decision process and the error caused by the decision algorithm, and can retain the noise of the original transmitter , effectively retaining the noise characteristics of the equalized receiver.
  • the output sequence Y(n) equalized by the reference equalizer can be expressed as:
  • x_in_syn(i) is the feedforward adaptive equalization signal sequence (i.e. the first equalization signal sequence)
  • Pattern(i) is a known test sequence
  • c i and d i are coefficients determined by the convergence of the adaptive algorithm, which can make Signal sequence Y(n) has the highest signal-to-noise ratio. It can be obtained from the above formula that Y(n) can be described by a specific linear formula on the premise of retaining the noise.
  • the conformance testing device determines the standard deviation of the maximum additive noise that the optical transmitter can support when reaching the target bit error rate according to the test eye diagram and the noise enhancement coefficient corresponding to the equalization compensation in step 603;
  • test parameter T the test parameter T ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇
  • OMA optical modulation amplitude of the test eye diagram
  • Qt is the Q value of the test sequence waveform
  • ⁇ G is the standard deviation of the maximum additive noise
  • ⁇ S is the standard deviation of the optical receiver noise
  • Ceq is the noise enhancement coefficient
  • N(f ) is the noise density function
  • Heq(f) is the frequency response function of the first equalization coefficient
  • test parameter T in this application can also be called TDECQ.
  • the optical signal is transmitted by the optical transmitter when the relative intensity noise is maximum, passing the optical signal consistency test indicates that the optical transmitter has passed the consistency test.
  • the first threshold can be set according to actual application requirements, and the specific value is not limited here.
  • the conformance testing device calculates the number of consecutive bit errors according to the test eye diagram and the signal sequence, if the value of the test parameter is less than or equal to the first threshold, and the number of consecutive bit errors is less than or equal to the first threshold two thresholds, the consistency testing device determines that the consistency test of the optical signal passes.
  • the second threshold can be set according to actual application requirements, and the specific value is not limited here.
  • the consistency test method provided by this application performs equalization compensation on the collected signal sequence through the test sequence, which can improve the equalization compensation effect, increase the acceptable additional noise margin of the system, improve the numerical accuracy of the test TDECQ, and optimize the test performance.
  • FIG. 8 is a schematic diagram of another embodiment of the consistency testing method provided in the embodiment of the application.
  • the method includes steps 801-805 .
  • step 603 Please refer to step 603 for the specific implementation process.
  • Step 803 includes obtaining the test eye diagram and calculating the value of the test parameter T, for details, please refer to steps 604 and 605 .
  • the conformance testing device calculates the number of consecutive bit errors according to the test eye diagram and the signal sequence, and judges whether the number of consecutive bit errors is less than or equal to the second threshold, and if so, executes step 805; if If not, the conformance testing device judges that the conformance test of the optical transmitter fails.
  • the conformance testing device judges that the conformance test of the optical transmitter is passed. If not, the conformance testing device judges that the conformance test of the optical transmitter fails.
  • the input signal X_in is a signal collected by the standard receiver O/E, and its data collection length needs to be greater than the length of the test sequence stored in the sequence storage unit.
  • the sequence alignment function X_in_ds cross-correlates with the pattern to get the length of X_in_ds that needs to be translated, and then enters the equalization process after outputting the alignment signal X_in_syn.
  • part A of the frame line is the FFE equalization process
  • part B is the sequence feedback equalization process.
  • the nth X_in_syn sequence enters FFE equalization
  • T is the delay operation, that is, the signal at the sampling moment before the nth signal of x_in_syn is selected, that is, the n-1th x_in_syn signal, and so on, and then T operation is performed again, Then take out the n-2th x_in_syn signal.
  • the length of the participating signal is determined by the number of FFE equalization coefficients.
  • ⁇ x_in_syn(n), x_in_syn(n-1), x_in_syn(n-2),... ⁇ signals are multiplied with the first equalization coefficients ⁇ c_n, c_n-1, c_n-2,... ⁇ in turn to get ⁇ x_in_syn (n)*c_n, x_in_syn(n-1)*c_n-1,... ⁇ , and then do the addition operation.
  • the FFE equalization process can be implemented through memory, multiplication gates and addition circuits.
  • the first equalization coefficient ⁇ Ci ⁇ is obtained by an adaptive algorithm, for example, it may be the signal-to-noise ratio of the feed-forward equalization output sequence.
  • the test sequence Pattern(n) first passes the T delay operation, selects the n-1th signal, and so on selects n-2, n-3 signals, The length of the participating operation is determined by the length of the feedback equalization coefficient.
  • ⁇ Pattern(n-1), Pattern(n-2),... ⁇ sequence is multiplied by ⁇ d(n-1), d(n-2), d(n-3),... ⁇ , the second equalization
  • the coefficient ⁇ di ⁇ is obtained by an adaptive algorithm. It can be obtained that the output signal Y(n) can be expressed as:
  • the adaptive equalization method between the output sequence Y(n) and the original pattern, as well as ⁇ Ci ⁇ and ⁇ di ⁇ are determined by the adaptive algorithm, and will not be discussed in detail here.
  • a possible data processing flow is introduced below from the perspective of the system architecture of the receiving end, as shown in FIG. 10 .
  • the sequence storage unit stores the test sequence, which is used for sequence alignment in the down-sampling step, and is also used for sending the test sequence to the sequence feedback equalization device for further equalization processing.
  • the receiving end performs down-sampling on the collected input signal X to obtain data X_in, and inputs X_in into the feedforward equalization device for equalization.
  • the first equalization coefficient of the feedforward equalization device is ⁇ ci ⁇
  • the output is the first equalization sequence Y_FFE, and continues through the sequence
  • the feedback equalization device performs equalization, the second equalization coefficient is ⁇ di ⁇ , and the output second equalization sequence is Y_out.
  • FIG. 11 is a schematic diagram of a calculation process of a receiving end in an embodiment of the present application.
  • the value of the test parameter TDECQ can be obtained through formula calculation, and then the conformance test performance of the transmitter can be judged.
  • the consistency test method provided by the embodiment of the present application, considering that in the high signal rate scenario, the existing consistency test scheme test has too high requirements on the performance of the equipment, and the test accuracy is reduced, and the reference equalizer is improved, based on the known test sequence Perform equalization compensation on the collected signal sequence, synthesize the test eye diagram based on the equalization coefficient of the equalization compensation, calculate the value of the test parameter TDECQ according to the test eye diagram and the noise enhancement coefficient updated based on the equalization compensation, and use it to judge the optical signal transmitter
  • This method can improve the acceptable additional noise margin of the system, improve the numerical accuracy of the test TDECQ, and optimize the test performance.
  • FIG. 12 is a schematic structural diagram of a consistency test device provided by the embodiment of this application .
  • the conformance test set includes:
  • the acquisition unit 1201 is used to acquire the signal sequence of the optical signal received by the optical receiver, the optical signal is generated by the optical transmitter using the four-level pulse amplitude modulation PAM4 mode modulation test sequence;
  • the processing unit 1203 is configured to perform equalization compensation on the signal sequence according to the test sequence, and synthesize a test eye diagram according to the equalization coefficient of the signal sequence obtained through the equalization compensation;
  • Calculation unit 1204 configured to calculate the value of the test parameter according to the test eye diagram and the noise enhancement coefficient corresponding to the equalization compensation
  • the determination unit 1205 is configured to determine that the consistency test of the optical signal passes when the value of the test parameter is less than or equal to the first threshold.
  • passing the optical signal consistency test indicates that the optical transmitter passes the consistency test.
  • the calculating unit 1204 is also used for:
  • the determining unit 1205 is specifically used for:
  • processing unit 1203 is specifically configured to:
  • a feedforward adaptive equalization is performed on the first equalized signal sequence according to the test sequence to obtain a second equalization coefficient.
  • processing unit 1203 is specifically configured to:
  • test eye diagram is synthesized according to the equalization coefficient of the signal sequence.
  • the computing unit 1204 is specifically configured to:
  • test eye diagram and the noise enhancement coefficient determine the standard deviation of the maximum additive noise that the optical transmitter can support when reaching the target bit error rate
  • the value of the test parameter is determined according to the standard deviation of the maximum additive noise that the optical transmitter can support when the target bit error rate is reached.
  • the computing unit 1204 is specifically configured to:
  • OMA optical modulation amplitude of the test eye diagram
  • Qt is the Q value of the test sequence waveform
  • ⁇ G is the standard deviation of the maximum additive noise
  • ⁇ S is the standard deviation of the optical receiver noise
  • Ceq is the noise enhancement coefficient
  • N(f) is the noise density function
  • Heq(f) is the frequency response function of the first equalization coefficient
  • the length of the signal sequence is greater than or equal to the length of the test sequence
  • the processing unit 1203 is specifically used for:
  • Sequence alignment is performed on the signal sequence according to the test sequence, and the equalization compensation is performed on the sequence-aligned signal sequence.
  • the conformance test device performs equalization compensation on the collected signal sequence based on the known test sequence, synthesizes the test eye diagram based on the equalization coefficient of the equalization compensation, and calculates according to the test eye diagram and the noise enhancement coefficient updated based on the equalization compensation
  • the value of the test parameter TDECQ is used to judge whether the conformance test of the optical signal transmitter has passed, which can increase the acceptable additional noise margin of the system, improve the numerical accuracy of the test TDECQ, and optimize the test performance.
  • FIG. 13 is a schematic structural diagram of another conformance testing device provided in the embodiment of the present application.
  • the conformance test apparatus 1300 may specifically be a processing device with a processing function, for example, a computer, a server, etc. independent of the test system, or an oscilloscope in the test system.
  • the execution subject of the embodiment of the present application is a processing device independent of the test system
  • the above-mentioned reference equalizer may exist independently in the test system, or may be integrated in an oscilloscope of the test system, or may be integrated in the processing device.
  • the above-mentioned reference equalizer when the above-mentioned reference equalizer is integrated in a processing device (for example, a processing device independent of the test system, or an oscilloscope in the test system), the above-mentioned reference equalizer can be implemented by means of hardware and/or software accomplish.
  • the above-mentioned reference equalizer can be realized by constructing a reference equalizer model in a processing device.
  • the specific equipment form of the consistency testing device is not limited.
  • the conformance testing device 1300 may have relatively large differences due to different configurations or performances, and may include one or more processors 1301 and memory 1302, and programs or data are stored in the memory 1302.
  • the memory 1302 uses for storing test sequences.
  • the storage 1302 may be a volatile storage or a non-volatile storage.
  • the processor 1301 is one or more central processing units (central processing unit, CPU), and the CPU may be a single-core CPU or a multi-core CPU.
  • the processor 1301 can communicate with the memory 1302 , and execute a series of instructions in the memory 1302 on the conformance testing device 1300 .
  • the conformance testing device 1300 also includes one or more network interfaces 1303, such as Ethernet interfaces, optical fiber interfaces and the like.
  • the conformance testing device 1300 may also include one or more power supplies; one or more input and output interfaces, and the input and output interfaces may be used to connect a display, a mouse, a keyboard, a touch screen device or sensing equipment, etc.
  • the disclosed system, device and method can be implemented in other ways.
  • the device embodiments described above are only illustrative.
  • the division of the units is only a logical function division. In actual implementation, there may be other division methods.
  • multiple units or components can be combined or May be integrated into another system, or some features may be ignored, or not implemented.
  • the mutual coupling or direct coupling or communication connection shown or discussed may be through some interfaces, and the indirect coupling or communication connection of devices or units may be in electrical, mechanical or other forms.
  • the units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place, or may be distributed to multiple network units. Part or all of the units can be selected according to actual needs to achieve the purpose of the solution of this embodiment.
  • each functional unit in each embodiment of the present application may be integrated into one processing unit, each unit may exist separately physically, or two or more units may be integrated into one unit.
  • the above-mentioned integrated units can be implemented in the form of hardware or in the form of software functional units.
  • the integrated unit is realized in the form of a software function unit and sold or used as an independent product, it can be stored in a computer-readable storage medium.
  • the technical solution of the present application is essentially or part of the contribution to the prior art or all or part of the technical solution can be embodied in the form of a software product, and the computer software product is stored in a storage medium , including several instructions to make a computer device (which may be a personal computer, a server, or a network device, etc.) execute all or part of the steps of the methods described in the various embodiments of the present application.
  • the aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (read-only memory, ROM), random access memory (random access memory, RAM), magnetic disk or optical disc and other media that can store program codes. .

Landscapes

  • Physics & Mathematics (AREA)
  • Electromagnetism (AREA)
  • Engineering & Computer Science (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Signal Processing (AREA)
  • Optical Communication System (AREA)

Abstract

La présente demande divulgue un procédé de test de cohérence et un appareil associé, qui sont utilisés pour effectuer un test de cohérence entre un émetteur optique et un récepteur optique dans un scénario à débit de signal élevé. Le procédé de la présente demande consiste à : collecter une séquence de signaux optiques, qui sont reçus par un récepteur optique, les signaux optiques étant générés au moyen d'un émetteur optique modulant une séquence test à l'aide d'une modulation d'impulsions en amplitude à 4 niveaux ; acquérir la séquence test ; effectuer une compensation d'égalisation sur la séquence de signal selon la séquence test ; synthétiser un diagramme d'œil test selon un coefficient d'égalisation de la séquence de signal qui est obtenu au moyen de la compensation d'égalisation ; calculer la valeur d'un paramètre de test selon le diagramme d'œil test et un coefficient d'amélioration de bruit correspondant à la compensation d'égalisation ; et si la valeur du paramètre de test est inférieure ou égale à une première valeur de seuil, alors déterminer qu'un test de cohérence des signaux optiques est réussi. Au moyen du procédé, une marge de bruit supplémentaire acceptable dans un système peut être augmentée, la précision numérique d'un TDECQ test peut être améliorée, et les performances de test peuvent être optimisées.
PCT/CN2023/070628 2022-01-27 2023-01-05 Procédé de test de cohérence et appareil associé WO2023142939A1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
CN202210101984.7 2022-01-27
CN202210101984.7A CN116566481A (zh) 2022-01-27 2022-01-27 一致性测试方法和相关装置

Publications (1)

Publication Number Publication Date
WO2023142939A1 true WO2023142939A1 (fr) 2023-08-03

Family

ID=87470557

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/CN2023/070628 WO2023142939A1 (fr) 2022-01-27 2023-01-05 Procédé de test de cohérence et appareil associé

Country Status (2)

Country Link
CN (1) CN116566481A (fr)
WO (1) WO2023142939A1 (fr)

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN112448760A (zh) * 2019-08-31 2021-03-05 华为技术有限公司 一种获取发射机测试参数的方法和装置以及存储介质
CN112462121A (zh) * 2020-10-13 2021-03-09 中国科学院微电子研究所 一种眼图示波器系统及眼图测试方法
CN112803997A (zh) * 2018-04-27 2021-05-14 华为技术有限公司 一致性测试方法、装置和存储介质
CN113063977A (zh) * 2021-03-19 2021-07-02 合肥京东方显示技术有限公司 模拟测试方法、装置及计算机可读存储介质
WO2021164195A1 (fr) * 2020-02-17 2021-08-26 华为技术有限公司 Procédé et appareil de réglage de taille de pas pour égaliseur adaptatif, récepteur de signal et système

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN112803997A (zh) * 2018-04-27 2021-05-14 华为技术有限公司 一致性测试方法、装置和存储介质
CN112448760A (zh) * 2019-08-31 2021-03-05 华为技术有限公司 一种获取发射机测试参数的方法和装置以及存储介质
WO2021164195A1 (fr) * 2020-02-17 2021-08-26 华为技术有限公司 Procédé et appareil de réglage de taille de pas pour égaliseur adaptatif, récepteur de signal et système
CN112462121A (zh) * 2020-10-13 2021-03-09 中国科学院微电子研究所 一种眼图示波器系统及眼图测试方法
CN113063977A (zh) * 2021-03-19 2021-07-02 合肥京东方显示技术有限公司 模拟测试方法、装置及计算机可读存储介质

Also Published As

Publication number Publication date
CN116566481A (zh) 2023-08-08

Similar Documents

Publication Publication Date Title
CN110417463B (zh) 一致性测试方法、装置和存储介质
US8009981B2 (en) Testing of transmitters for communication links by software simulation of reference channel and/or reference receiver
US7664394B2 (en) Testing of receivers with separate linear O/E module and host used in communication links
US8111986B1 (en) Testing of transmitters for communication links by software simulation of reference channel and/or reference receiver
US8873615B2 (en) Method and controller for equalizing a received serial data stream
WO2021036220A1 (fr) Procédé et appareil pour obtenir le paramètre de test d'un émetteur, et support d'enregistrement
US20040268190A1 (en) Adjusting parameters of a serial link
US9596104B2 (en) Blind equalization tap coefficient adaptation in optical systems
US8254781B2 (en) Testing of receivers with separate linear O/E module and host used in communication links
US7295774B2 (en) Performance monitoring for optical links
JP2023026403A (ja) 試験測定装置及び被試験デバイスの試験方法
KR101210686B1 (ko) 통신 시스템에서의 수신 등화 장치 및 수신 등화 방법
WO2023142939A1 (fr) Procédé de test de cohérence et appareil associé
GB2428169A (en) Method and apparatus for providing diagnostic features for an optical transceiver
CN114389751B (zh) 一种用于误码测试设备的自动均衡方法和系统
WO2023142846A1 (fr) Procédé de test de conformité, dispositif et système
WO2024060769A1 (fr) Procédé de test tdec et dispositif associé
CN117728892B (zh) 1.6t lpo或cpo光模块的光信号弹性自适应处理方法
WO2018086117A1 (fr) Procédé de traitement d'erreur, et appareil de traitement d'erreur
WO2019206204A1 (fr) Procédé et dispositif de vérification de conformité, et support de stockage
Erb et al. An FPGA based diagnostic tool for jitter optimization in serial high-speed transceivers

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 23745824

Country of ref document: EP

Kind code of ref document: A1