Estimation Method of Optical Signal-to-Noise Ratio

Abstract

The present application relates to the field of optical communication technology, and discloses a method for estimating an optical signal-to-noise ratio. The method includes: inserting a predetermined number of consecutive zero sequences in a subframe of a frame structure of an optical signal sequence according to a predetermined period, and sending the optical signal sequence to a receiving end; the receiving end receives the optical signal sequence and determines whether the current subframe of the optical signal sequence includes a consecutive zero sequence; if so, obtaining the signal at the position of the consecutive zero sequence in the subframe, and removing the part of the signal adjacent to other parts of the subframe to obtain a noise sequence; using the Berg algorithm to perform noise whitening on the noise sequence, and calculating the power of the noise sequence after the noise whitening process; if not, selecting the load signal at a part of the subframe as the effective load signal and calculating the power of the effective load signal; calculating the optical signal-to-noise ratio according to the power of the noise sequence and the power of the effective load signal. The present invention reduces the colored distortion of the noise during transmission and significantly improves the accuracy of link OSNR estimation.

Description

Technical Field

[0001] The present application relates to the field of optical communication technology, and in particular to an optical signal-to-noise ratio estimation method. Background Art

[0002] Optical Signal Noise Ratio (OSNR) measurement and reporting is an important means of digital diagnostic monitoring (DDM) of optical communication links. OSNR is defined as:

[0003]

[0004] Where P sig is the effective signal power in the band, P noise It is the in-band noise power within a fixed 0.1nm bandwidth.

[0005] Early point-to-point networks generally monitor and report by measuring out-of-band OSNR. This method measures the out-of-band noise in the non-valid signal area to obtain the OSNR value, such as Figure 1 As shown in the figure, the out-of-band OSNR measurement method assumes that the noise is a broadband signal and that the out-of-band and in-band noises are basically the same. When the network evolves to a more complex level, such as in a ROADM network, the assumption of this method is generally difficult to hold, resulting in a large measurement error.

[0006] Therefore, it is necessary to measure the in-band noise. However, the signal and noise in the in-band part are mixed together. How to separate the signal and noise without interrupting the actual business is a problem. A common practice at present is to send a signal sequence of 0 at certain positions in the frame structure design, obtain the signals at these positions at the receiving end as the fiber link noise signal, calculate the noise power, and thus calculate the OSNR value. This method can improve the OSNR accuracy compared with the out-of-band noise method. This method is called the zero insertion method here, such as Figure 2 shown.

[0007] In long-distance optical fiber transmission, due to various optical fiber link damages and multi-level filtering effects in complex networking, one problem that the zero insertion method needs to face is the colored distortion of noise. For example, since the digital signal at the receiving end needs to be equalized after long-distance transmission, the link white noise will become colored noise, which will cause the error deviation of the base noise estimation and reduce the accuracy of the OSNR estimation value. In addition, inter-symbol interference (ISI) will also cause the formation of colored noise.

[0008] This section is intended to provide a background or context to the embodiments of the present application as recited in the claims. The description herein is not admitted to be prior art as disclosed by virtue of its inclusion in this section. Summary of the invention

[0009] The purpose of this application is to provide an optical signal-to-noise ratio estimation method to reduce the colored distortion of noise during transmission and significantly improve the link OSNR estimation accuracy.

[0010] The present application discloses a method for estimating an optical signal-to-noise ratio, comprising:

[0011] Inserting a predetermined number of consecutive zero sequences into a subframe of a frame structure of an optical signal sequence according to a predetermined period, and sending the optical signal sequence to a receiving end;

[0012] The receiving end receives the optical signal sequence and determines whether a current subframe of the optical signal sequence includes a continuous zero sequence;

[0013] If yes, obtain a signal at the position where the continuous zero sequence is located in the subframe, and remove a portion of the signal adjacent to other portions of the subframe to obtain a noise sequence;

[0014] Performing noise whitening processing on the noise sequence using the Berg algorithm, and calculating the power of the noise sequence after the noise whitening processing;

[0015] If not, selecting a load signal at a portion of the subframe as an effective load signal and calculating the power of the effective load signal; and

[0016] The optical signal-to-noise ratio is calculated according to the power of the noise sequence and the power of the effective load signal.

[0017] In a preferred example, the noise whitening process further comprises:

[0018] Perform a p-order Berg estimation on the noise sequence R, assuming that the length of the noise sequence is N1 and the whitening coefficient is a m ,m 1,2,...,p,initialize the forward sequence to efp 0 = R, initialize the backward sequence to ebp 0 =R, the mth-order coefficient is

[0019]

[0020] Among them, efp m =efp m-1 (2:end+k m ebp m-1 (1:end-1);

[0021] ebpm =ebp m-1 (1:end-1)+k m efp m-1 (2:end;

[0022] a m =[a m-1 ;0]+k m [0;conj(flipud(a m-1 );

[0023] The noise sequence after the noise whitening process is R′=conv(R,a m );

[0024] Among them, efp m and ebp m is the forward sequence and backward sequence at the mth iteration, m 1,2,...,p. n is efp m and ebp m The sequence subscript of , when the m-th iteration, the value range of subscript n is (0, N1-m); conj() is the conjugate function, flipud is the data flipping function; conv() is the convolution function.

[0025] In a preferred example, the p-order value of the Burg estimate is 1st order or 2nd order.

[0026] In a preferred example, after calculating the power of the noise sequence after the noise whitening process, the method further includes: calculating the average value of the power of the noise sequence within the window length as the power of the noise sequence.

[0027] In a preferred example, selecting a load signal at a portion of the subframe as an effective load signal and calculating the power of the effective load signal further includes: calculating an average value of the power of the effective load signal within a window length as the power of the effective load signal.

[0028] In a preferred example, the frame structure of the optical signal sequence includes a plurality of frames, each frame includes a plurality of subframes, and the continuous zero sequence is inserted at the same position of the same subframe in each frame.

[0029] In a preferred example, calculating the optical signal-to-noise ratio according to the power of the noise sequence and the power of the effective load signal further includes: calculating the signal-to-noise ratio according to the power of the noise sequence and the power of the effective load signal, and calculating the optical signal-to-noise ratio according to the signal-to-noise ratio, and the calculation formula of the optical signal-to-noise ratio and the signal-to-noise ratio is:

[0030]

[0031] Among them, OSNR is optical signal-to-noise ratio, SNR is signal-to-noise ratio, B s is the signal bandwidth, B ref is the reference bandwidth.

[0032] The present application also discloses an optical signal-to-noise ratio estimation system, comprising:

[0033] A transmitting end, configured to insert a predetermined number of consecutive zero sequences into a subframe of an optical signal sequence according to a predetermined period, and transmit the optical signal sequence;

[0034] A receiving end is used to receive the optical signal sequence and determine whether the current subframe of the optical signal sequence includes a continuous zero sequence; if so, obtain a signal at a position where the continuous zero sequence is located in the subframe, remove a portion of the signal adjacent to other portions of the subframe to obtain a noise sequence, perform noise whitening on the noise sequence using a Berg algorithm, and calculate the power of the noise sequence after the noise whitening process; if not, select a load signal at a portion of the subframe as an effective load signal and calculate the power of the effective load signal; and calculate the optical signal-to-noise ratio according to the power of the noise sequence and the power of the effective load signal.

[0035] The present application also discloses a computer-readable storage medium, wherein the computer-readable storage medium stores computer-executable instructions, and when the computer-executable instructions are executed by a processor, the steps in the aforementioned method are implemented.

[0036] Compared with the prior art, the main differences and effects of the embodiments of the present application are:

[0037] 1) It can reduce the colored distortion of noise during transmission and be closer to the base white noise in the actual link.

[0038] 2) Significantly improve the link OSNR estimation accuracy, with the error controlled within 0.5dB.

[0039] 3) Simple implementation.

[0040] The specification of the present application records a large number of technical features, which are distributed in various technical solutions. If all possible combinations of technical features of the present application (i.e., technical solutions) are to be listed, the specification will be too long. In order to avoid this problem, the various technical features disclosed in the above-mentioned invention content of the present application, the various technical features disclosed in the various embodiments and examples below, and the various technical features disclosed in the accompanying drawings can be freely combined with each other to form various new technical solutions (these technical solutions should all be regarded as having been recorded in this specification), unless the combination of such technical features is technically infeasible. For example, in one example, feature A+B+C is disclosed, and in another example, feature A+B+D+E is disclosed, and features C and D are equivalent technical means that play the same role. Technically, only one can be used, and it is impossible to use them at the same time. Feature E can be combined with feature C technically. Then, the solution of A+B+C+D should not be regarded as having been recorded because it is technically infeasible, and the solution of A+B+C+E should be regarded as having been recorded. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 It is a schematic diagram for measuring the out-of-band optical signal-to-noise ratio.

[0042] Figure 2 This is a schematic diagram of measuring the in-band optical signal-to-noise ratio using the zero-interpolation method.

[0043] Figure 3 It is a flowchart of a method for estimating an optical signal-to-noise ratio according to an embodiment of the present application.

[0044] Figure 4 It is a schematic diagram of inserting a continuous zero sequence into an optical signal sequence according to one embodiment of the present application.

[0045] Figure 5 It is a more detailed flowchart of the optical signal-to-noise ratio estimation method according to one embodiment of the present application.

[0046] Figure 6 This is the result of optical signal-to-noise ratio measurement in one embodiment of the present application. DETAILED DESCRIPTION

[0047] In the following description, many technical details are provided to help readers better understand the present application. However, those skilled in the art can understand that the technical solution claimed in the present application can be implemented even without these technical details and various changes and modifications based on the following embodiments.

[0048] Description of some concepts:

[0049] Optical Signal Noise Ratio (OSNR): OSNR refers to the power ratio of the optical signal to the noise on the optical link, usually expressed in dB. The main difference between OSNR and SNR is that the noise power defined by OSNR is limited to the in-band noise range of 0.1nm (about 12.5GHz), so there is a conversion relationship with SNR.

[0050] Burg Algorithm: A classic recursive algorithm that directly calculates the power spectrum estimate from a known time signal series. It was proposed by JP Burg, hence the name Burg Algorithm.

[0051] In order to make the objectives, technical solutions and advantages of the present application clearer, the implementation methods of the present application will be further described in detail below in conjunction with the accompanying drawings.

[0052] One embodiment of the present application relates to a method for estimating an optical signal-to-noise ratio, the process of which is as follows: Figure 1 As shown, the method comprises the following steps:

[0053] Step 101, insert a predetermined number of consecutive zero sequences in a subframe of a frame structure of an optical signal sequence according to a predetermined period, and send the optical signal sequence to a receiving end. In one embodiment, the frame structure of the optical signal sequence includes multiple frames, for example, multiple multiframes, each multiframe includes multiple subframes, for example, each frame includes N subframes, such as subframe 1, subframe 2, ..., subframe N, and a consecutive zero sequence is inserted at the same position of the same subframe of each multiframe. The term "consecutive zero sequence" means a continuous segment of data with a value of zero. For example, a consecutive zero sequence is inserted at the same position of subframe 1 of each multiframe. And, the optical signal sequence is sent to the receiving end in units of time slots.

[0054] Step 102: The receiving end receives the optical signal sequence and determines whether the current subframe of the optical signal sequence includes a continuous zero sequence. For example, the receiving end receives the time slot of the optical signal sequence and determines whether the current time slot is a time slot where the continuous zero sequence is located.

[0055] Step 103, if the receiving end determines that the current subframe includes a continuous zero sequence, obtain the signal at the position of the continuous zero sequence in the subframe, and remove the partial signal of the signal adjacent to other parts of the subframe to obtain a noise sequence. Specifically, if the receiving end determines that the current time slot is the time slot where the continuous zero sequence is located, it is determined that the current subframe includes a continuous zero sequence. It should be understood that the data signal adjacent to other parts of the subframe in the continuous zero sequence may be affected, so in the present application, a guard interval is added at both ends of the continuous zero sequence, that is, a part of the data signal (guard interval) adjacent to other parts of the subframe in the continuous zero sequence is removed.

[0056] Step 104: Use the Berg algorithm to perform noise whitening processing on the noise sequence, and calculate the power of the noise sequence after the noise whitening processing.

[0057] In one embodiment, the noise whitening process further comprises the following steps:

[0058] Perform p-order Berg estimation on the noise sequence R, assuming that the length of the noise sequence is N1 and the whitening coefficient is a m ,m 1,2,...,p,initialize the forward sequence to efp R,initialize the backward sequence to ebp R,the mth order coefficient is

[0059]

[0060] Among them, efp m =efp m-1 (2:end+k m ebp m-1 (1:end-1);

[0061] ebp m =ebp m-1 (1:end-1)+k m efp m-1 (2:end;

[0062] a m =[a m-1 ;0]+k m [0;conj(flipud(a m-1 );

[0063] The noise sequence after the noise whitening process is R′=conv(R,a m );

[0064] Among them, efp m and ebp m is the forward sequence and backward sequence at the mth iteration, m 1,2,...,p. n is efp m and ebp m The sequence subscript of , when the mth iteration, the value range of subscript n is (0, N1-m); conj() is the conjugate function, flipud is the data flipping function; conv() is the convolution function, the input R is the original noise sequence of length N1, the input a m is a whitening coefficient of length p, and the output R′ is a whitened noise sequence of length N1.

[0065] In one embodiment, the value of the p-order of the Burg estimate is 1st order or 2nd order.

[0066] In one embodiment, after calculating the power of the noise sequence after the noise whitening process, the method further includes: calculating an average value of the power of the noise sequence within the window length as the power of the noise sequence.

[0067] Step 105: If the receiving end determines that the current subframe does not include a continuous zero sequence, a load signal at a part of the subframe is selected as an effective load signal and the power of the effective load signal is calculated.

[0068] In one embodiment, selecting a load signal at a portion of a subframe as an effective load signal and calculating the power of the effective load signal further includes: calculating an average value of the power of the effective load signal within a window length as the power of the effective load signal.

[0069] Step 106: Calculate the optical signal-to-noise ratio according to the power of the noise sequence and the power of the effective load signal.

[0070] In one embodiment, the optical signal-to-noise ratio and the signal-to-noise ratio are calculated as follows:

[0071]

[0072] Among them, OSNR is optical signal-to-noise ratio, SNR is signal-to-noise ratio, B s is the signal bandwidth, B ref is the reference bandwidth.

[0073] In order to better understand the technical solution of the present application, a specific example is provided below for illustration. The details listed in the example are mainly for ease of understanding and are not intended to limit the scope of protection of the present application.

[0074] like Figure 4 As shown in the figure, in the effective load signal, according to the multiframe period, a zero sequence of length N is inserted at a fixed position, that is, no signal is sent in this time window. In an ideal state, the receiver receives the link base noise in this time window. In the link damage state, the noise signal at the receiver is distorted. The purpose of this is to make the distorted noise signal at the receiver reflect the link noise state more accurately as much as possible.

[0075] Factors to consider when using zero insertion include:

[0076] 1. Choose a reasonable zero insertion period. If the period is too short, it will lead to excessive overhead and affect random convergence. For example, if a zero sequence is inserted in multiple subframes of each multiframe, the overhead will inevitably increase compared to inserting a zero sequence in one subframe (such as subframe 1) of each multiframe.

[0077] 2. Choose a reasonable number of zero insertions. If the amount of zero insertion data is too short, inter-symbol interference will cause serious inaccurate noise estimation. For example, if the length of the zero insertion sequence is less than the inter-symbol interference length caused by the required dispersion, the zero insertion sequence is bound to be seriously polluted. Therefore, choose an appropriate number of zero insertions based on the inter-symbol interference length.

[0078] In order to solve the difficulty of noise estimation caused by colored noise, this method adds a guard interval and uses noise whitening technology to maximize the improvement of the noise signal. The processing flow chart is as follows Figure 5 shown.

[0079] First, determine whether it is the time slot where the continuous zero sequence is located. If so, find the position of the continuous zero sequence with a length of N, remove the protection intervals at both ends, and obtain a noise signal with a length of N1. Then, perform noise whitening, calculate the noise power and record the accumulated average value Pnoise, and perform window length counting. The window length count is based on the number of multiframes calculated according to the effective noise.

[0080] The present invention calculates the noise whitening coefficient by the Berg algorithm. The Berg algorithm is a recursive algorithm that directly calculates the power spectrum estimation value from the known time signal sequence, and can directly solve the reflection coefficient from the observed data. The algorithm is very effective for the power spectrum estimation of a shorter data sequence, and is therefore suitable for estimating and processing short sequence noise signals.

[0081] The specific implementation of the noise whitening processing module in this method is as follows.

[0082] 1. Perform p-order Berg estimation on the noise sequence to obtain the whitening coefficient a m ,=1,2,.... Assume that the input noise sequence is R, the length is N1, the initial forward sequence is efp R, and the backward sequence is ebp R.

[0083] The mth order coefficient is

[0084]

[0085] The recursive formula is

[0086] efp m =efp m-1 (2:end+k m ebp m-1 (1:end-1);

[0087] ebp m =ebp m-1 (1:end-1)+k m efp m-1 (2:end;

[0088] a m =[am-1 ;0]+k m [0;conj(flipud(a m-1 )

[0089] where efp m and ebp m is the forward sequence and backward sequence at the mth iteration, m 1,2,...,p. n is efp m and ebp m The sequence subscript of , when the mth iteration, the value range of subscript n is (0, N1-m); conj is the conjugate function, flipud is the data flip function. Generally, p 1 or 2 can be used.

[0090] 2. Perform whitening filtering on the noise sequence to obtain the noise signal after whitening correction:

[0091] R′=conv(n,a m )

[0092] Where conv() is the convolution function. Then the power of the new noise signal R′ can be calculated.

[0093] If it is not the time slot where the continuous zero sequence is located, select the load signal at some positions to obtain the effective signal to be calculated, calculate the signal power and record the cumulative average value Psig, and count the window length. When the average window length is reached, calculate the SNR Psig / noise and deduce the OSNR value.

[0094] Specifically, the signal-to-noise ratio (SNR) is defined as

[0095]

[0096] Where N 0 is the noise spectral density, B s is the signal bandwidth.

[0097] The optical signal-to-noise ratio (OSNR) is defined as

[0098]

[0099] Where P s is the signal power, B ref For reference bandwidth, the industry generally chooses a wavelength width of 0.1nm, and the corresponding frequency bandwidth range at a wavelength of 1550nm is approximately 12.5G. Therefore, the conversion relationship between OSNR and SNR is as follows:

[0100]

[0101] In high-speed optical communication chips, link damage and DSP digital signal processing chips can cause whitened noise to become colored noise. Noise whitening processing is introduced in OSNR reporting to calculate the whitening coefficient. In optical polarization multiplexing transmission, the two polarization signals can support independent calculation of whitening coefficients and can also support averaging processing. Figure 6 FIG. 4 is a result of measuring the optical signal-to-noise ratio in an embodiment. It can be seen from the figure that the OSNR measured by the OSNR estimation method of the present application is closer to the standard value.

[0102] The present application also discloses an optical signal-to-noise ratio estimation system, which includes a transmitting end and a receiving end. The transmitting end is used to insert a predetermined number of consecutive zero sequences in a subframe of an optical signal sequence according to a predetermined period, and send the optical signal sequence. The receiving end is used to receive the optical signal sequence and determine whether the current subframe of the optical signal sequence includes a consecutive zero sequence. If so, obtain the signal at the position of the consecutive zero sequence in the subframe, and remove the part of the signal adjacent to other parts of the subframe to obtain a noise sequence, use the Berg algorithm to perform noise whitening on the noise sequence, and calculate the power of the noise sequence after the noise whitening process. If not, select the load signal at a part of the position in the subframe as the effective load signal and calculate the power of the effective load signal; and the receiving end calculates the optical signal-to-noise ratio according to the power of the noise sequence and the power of the effective load signal.

[0103] The first implementation manner is a method implementation manner corresponding to the present implementation manner. The technical details in the first implementation manner can be applied to the present implementation manner, and the technical details in the present implementation manner can also be applied to the first implementation manner.

[0104] Accordingly, the present application also provides a computer-readable storage medium in which computer executable instructions are stored, and when the computer executable instructions are executed by a processor, the various method embodiments of the present application are implemented. Computer-readable storage media include permanent and non-permanent, removable and non-removable media, and information storage can be implemented by any method or technology. Information can be a computer-readable instruction, a data structure, a module of a program, or other data. Examples of computer storage media include, but are not limited to, phase change memory (PRAM, static random access memory (SRAM, dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technology, read-only compact disk read-only memory (CD-ROM), digital versatile disk (DVD) or other optical storage, magnetic cassettes, magnetic tape magnetic disk storage or other magnetic storage devices or any other non-transmission media that can be used to store information that can be accessed by a computing device. As defined herein, computer-readable storage media does not include temporary computer-readable media (transitory media), such as modulated data signals and carriers.

[0105] In addition, the embodiment of the present application also provides an optical signal-to-noise ratio estimation system, which includes a memory for storing computer executable instructions, and a processor; the processor is used to implement the steps in the above-mentioned method implementations when executing the computer executable instructions in the memory. Among them, the processor can be a central processing unit (Central Processing Unit, referred to as "CPU"), or other general-purpose processors, digital signal processors (Digital Signal Processor, referred to as "DSP"), Application Specific Integrated Circuit (Application Specific Integrated Circuit, referred to as "ASIC"), etc. The aforementioned memory can be a read-only memory (read-only memory, referred to as "ROM"), a random access memory (random access memory, referred to as "RAM"), a flash memory (Flash), a hard disk or a solid-state hard disk, etc. The steps of the method disclosed in each embodiment of the present invention can be directly embodied as being executed by a hardware processor, or executed by a combination of hardware and software modules in the processor.

[0106] It should be noted that in the application documents of this patent, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that the process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "including one" do not exclude the existence of other identical elements in the process, method, article or device including the elements. In the application documents of this patent, if it is mentioned that an action is performed according to an element, it means that the action is performed at least according to the element, which includes two situations: performing the action only according to the element, and performing the action according to the element and other elements. Expressions such as multiple, multiple, and multiple include 2, 2 times, 2 kinds, and more than 2, more than 2 times, and more than 2 kinds.

[0107] All documents mentioned in this specification are considered to be included in the disclosure of this application as a whole, so that they can be used as a basis for modification when necessary. In addition, it should be understood that the above is only a preferred embodiment of this specification and is not intended to limit the scope of protection of this specification. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of one or more embodiments of this specification should be included in the scope of protection of one or more embodiments of this specification.

[0108] In some cases, the actions or steps described in the claims may be performed in a different order than in the embodiments and still achieve the desired results. In addition, the processes depicted in the drawings do not necessarily require the specific order or sequential order shown to achieve the desired results. In some embodiments, multitasking and parallel processing are also possible or may be advantageous.

Claims

1. A method for estimating an optical signal-to-noise ratio, characterized in that: include: Inserting a predetermined number of consecutive zero sequences into a subframe of a frame structure of an optical signal sequence according to a predetermined period, and sending the optical signal sequence to a receiving end; The receiving end receives the optical signal sequence and determines whether a current subframe of the optical signal sequence includes a continuous zero sequence; If yes, obtain a signal at the position of the continuous zero sequence in the subframe, and remove a portion of the signal adjacent to other portions of the subframe from the obtained signal at the position of the continuous zero sequence to obtain a noise sequence, wherein the removed portion of the signal is a guard interval located at both ends; The noise sequence is subjected to noise whitening processing by using the Berg algorithm, and the power of the noise sequence after the noise whitening processing is calculated. The noise whitening processing further includes: performing a p-order Berg estimation on the noise sequence R, assuming that the length of the noise sequence is N1, and the whitening coefficient is a m , m=1,2,...,p, initialize the forward sequence to efp0=R, initialize the backward sequence to ebp0=R, and the mth order coefficient is in, ebp m =ebp m-1 (1:end-1)+k m efp m-1 (2:end); a m =[a m-1 ;0]+k m [0;conj(flipud(a m-1 ); the noise sequence after the noise whitening process is R′=conv(R,a m ), where efp m and ebp m are the forward and backward sequences at the mth iteration, m = 1, 2, ..., p, and n is efp m and ebp m The sequence subscript of , when the mth iteration, the value range of subscript n is (0, N1-m); conj() is the conjugate function, flipud() is the data flipping function; conv() is the convolution function; If not, selecting a load signal at a portion of the subframe as an effective load signal and calculating the power of the effective load signal; and The optical signal-to-noise ratio is calculated according to the power of the noise sequence and the power of the effective load signal.

2. The estimation method according to claim 1, characterized in that The p-order value of the Burg estimate is 1st order or 2nd order.

3. The estimation method according to claim 1, characterized in that After calculating the power of the noise sequence after the noise whitening process, the method further includes: calculating an average value of the power of the noise sequence within the window length as the power of the noise sequence.

4. The estimation method according to claim 3, characterized in that: Selecting the load signal at a part of the subframe as the effective load signal and calculating the power of the effective load signal further includes: calculating the average value of the power of the effective load signal within the window length as the power of the effective load signal.

5. The estimation method according to claim 1, characterized in that: The frame structure of the optical signal sequence includes a plurality of frames, each frame includes a plurality of subframes, and the continuous zero sequence is inserted in the same position of the same subframe in each frame.

6. The estimation method according to claim 1, characterized in that: Calculating the optical signal-to-noise ratio according to the power of the noise sequence and the power of the effective load signal further includes: calculating the signal-to-noise ratio according to the power of the noise sequence and the power of the effective load signal, and calculating the optical signal-to-noise ratio according to the signal-to-noise ratio, and the calculation formula of the optical signal-to-noise ratio and the signal-to-noise ratio is: Among them, OSNR is optical signal-to-noise ratio, SNR is signal-to-noise ratio, B s is the signal bandwidth, B ref is the reference bandwidth.

7. An optical signal-to-noise ratio estimation system, characterized in that: include: A transmitting end, configured to insert a predetermined number of consecutive zero sequences into a subframe of a frame structure of an optical signal sequence according to a predetermined period, and transmit the optical signal sequence; A receiving end, configured to receive the optical signal sequence and determine whether a current subframe of the optical signal sequence includes a continuous zero sequence; If yes, obtain the signal at the position of the continuous zero sequence in the subframe, and remove the part of the signal adjacent to other parts of the subframe in the obtained signal at the position of the continuous zero sequence to obtain a noise sequence, wherein the removed part of the signal is the guard interval at both ends, perform noise whitening processing on the noise sequence using the Berg algorithm, and calculate the power of the noise sequence after the noise whitening processing; if no, select the load signal at a part of the position in the subframe as the effective load signal and calculate the power of the effective load signal; and calculate the optical signal-to-noise ratio according to the power of the noise sequence and the power of the effective load signal; The noise whitening process further includes: performing a p-order Berg estimation on the noise sequence R, assuming that the length of the noise sequence is N1 and the whitening coefficient is a m , m=1,2,...,p, initialize the forward sequence to efp0=R, initialize the backward sequence to ebp0=R, and the mth order coefficient is Among them, efp m =efp m-1 (2:end)+k m ebp m-1 (1:end-1);ebp m =ebp m-1 (1:end-1)+k m efp m-1 (2:end); a m =[a m-1 ;0]+k m [0;conj(flipud(a m-1 ); the noise sequence after the noise whitening process is R′=conv(R,a m ), where efp m and ebp m are the forward and backward sequences at the mth iteration, m = 1, 2, ..., p, and n is efp m and ebp m The sequence subscript of , when the m-th iteration, the value range of the subscript n is (0, N1-m); conj() is the conjugate function, flipud() is the data flipping function; conv() is the convolution function.

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