CN102315894B - Channel allocation method, channel decorrelation method and DWDM (dense wavelength division multiplexing) transmission experimental system - Google Patents

Abstract

The invention discloses a channel allocation method, a channel de-correlation method and a DWDM transmission experiment system, which are used for allocating the wavelength channel of the transmitter to the delay line in the dense wavelength division multiplexing transmission experiment system. The channel allocation method includes: a first allocation step: respectively select M wavelength channels closest to the wavelength channel to be measured from the wavelength channels contained in each transmitter, and assign the M wavelength channels of each transmitter selected The number of wavelength channels is assigned to M delay lines in one-to-one correspondence, and the second allocation step: the remaining wavelength channels are distributed to the M delay lines evenly as much as possible, and the difference between any two wavelengths from the same transmitter is The wavelength channels of NΔλ are not allocated to the same delay line.

Description

Channel allocation method, channel decorrelation method and DWDM transmission experimental system

technical field

The invention relates to the communication field, in particular to a channel de-correlation method and device in a dense wavelength division multiplexing transmission experimental system, and a dense wavelength division multiplexing transmission experimental system.

Background technique

In Dense Wavelength Division Multiplexing (DWDM) systems, phase noise caused by Cross-Phase Modulation (Cross-PhaseModulation, XPM) is one of the main reasons affecting system performance. In order to estimate the impact of cross-phase modulation, a common method is to conduct multi-channel transmission experiments in the laboratory. The traditional experimental method is the odd-even decorrelation method, which has been widely used in various multi-channel transmission experiments. In this method, all odd-numbered channels pass through the same optical transmitter, all even-numbered channels pass through another optical transmitter, and finally all channels are combined to form a dense wavelength division multiplexing experimental transmitting system. However, traditional parity decorrelation methods cannot correctly estimate the impact of cross-phase modulation in practical optical communication systems.

Contents of the invention

An object of the present invention is to provide a channel de-correlation method and device for multi-channel transmission experiments, by means of which method and device can effectively realize channel de-correlation in a dense wavelength division multiplexing experimental system. A brief overview of the invention is given below in order to provide a basic understanding of some aspects of the invention. It should be understood that this summary is not an exhaustive overview of the invention. It is not intended to identify key or critical parts of the invention nor to delineate the scope of the invention. Its purpose is merely to present some concepts in a simplified form as a prelude to the more detailed description that is discussed later.

According to one embodiment of the present invention, there is provided a method for allocating wavelength channels of transmitters to delay lines in a dense wavelength division multiplexing transmission experimental system, wherein the system includes N transmitters, N× M couplers and M delay lines, each transmitter includes at least M wavelength channels and the number of channels of different transmitters differs by at most one, and the wavelength difference between adjacent wavelength channels is Δλ, where N and M are natural numbers, so The method includes: a first allocation step: respectively select M wavelength channels closest to the wavelength channel to be measured from the wavelength channels contained in each transmitter, and assign the selected M wavelength channels of each transmitter to One-to-one correspondence is allocated to the M delay lines, and the second allocation step: distribute the remaining wavelength channels as many as possible to the M delay lines evenly, and make the difference between any two wavelengths from the same transmitter be the wavelength of NΔλ Channels are not assigned to the same delay line.

By means of this method, any number of channels can be processed, especially, multi-channel transmission experiments can be carried out with relatively low equipment complexity.

In addition, according to an embodiment of the present invention, there is also provided a method for determining the length of the delay line in the dense wavelength division multiplexing transmission experimental system, including: obtaining the minimum delay time, determining the minimum delay length according to the minimum delay time, And the corresponding length of the delay line is determined based on the minimum delay length, so that the length of the delay line is arranged from small to large to form a sequence of unequal differences.

Because the unequal difference sequence is used in this method, the periodicity of sequence growth is avoided, that is, the periodicity of the difference between adjacent two items of the sequence is avoided, and the actual system can be better simulated.

In addition, according to an embodiment of the present invention, there is also provided a method for decorrelating channels in a dense wavelength division multiplexing transmission experimental system, including: providing a dense wavelength division multiplexing transmission experimental system, wherein the system Including N transmitters, N×M couplers and M delay lines, each transmitter includes at least M wavelength channels and the number of channels of different transmitters differs by at most one, and the wavelength difference between adjacent wavelength channels is Δλ, Wherein N and M are natural numbers, and the wavelength channel of the transmitter is allocated to M delay lines; wherein the length of the M delay lines is determined by the following method: obtain the minimum delay time, and determine the minimum delay length according to the minimum delay time , respectively determine the corresponding lengths of the M delay lines based on the minimum delay length, so that the lengths of the delay lines form an unequal difference sequence when they are arranged from small to large; where the wavelength channels of the transmitter are allocated to the M delay lines The steps include: a first allocation step: respectively select M wavelength channels closest to the wavelength channel to be measured from the wavelength channels included in each transmitter, and combine the selected M wavelength channels of each transmitter into one One is allocated to M delay lines correspondingly, and the second allocation step: distribute the remaining wavelength channels as many as possible to the M delay lines evenly, and make any two wavelength channels from the same transmitter whose wavelength difference is NΔλ are not assigned to the same delay line.

This method has the advantage that, on the one hand, an arbitrary number of channels can be processed, and on the other hand, the actual system can be better simulated.

In addition, according to an embodiment of the present invention, there is also provided a wavelength selection unit for distributing the wavelength channel of the transmitter to the delay line in the dense wavelength division multiplexing transmission experimental system, wherein the system also includes N transmitters, N×M couplers and M delay lines, each transmitter includes at least M wavelength channels and the number of channels of different transmitters differs by at most one, and the wavelength difference between adjacent wavelength channels is Δλ, where N , M is a natural number, the wavelength selection unit includes: a first allocator configured to select M wavelength channels closest to the wavelength channel to be measured from the wavelength channels included in each transmitter, and The selected M wavelength channels of each transmitter are assigned to the M delay lines in one-to-one correspondence, and the second distributor is configured to distribute the remaining wavelength channels to the M delay lines as equally as possible. , and any two wavelength channels from the same transmitter with a wavelength difference of NΔλ are not allocated to the same delay line.

In addition, according to an embodiment of the present invention, a dense wavelength division multiplexing transmission experiment system is also provided, including N transmitters, N×M couplers, M delay lines and wavelength selection units, and each transmitter includes There are at least M wavelength channels and the number of channels of different transmitters differs by at most one, and the wavelength difference between adjacent wavelength channels is Δλ, where N and M are natural numbers, wherein the length of the M delay lines is determined by the following method: Obtain the minimum delay time, determine the minimum delay length according to the minimum delay time, and determine the corresponding lengths of the M delay lines based on the minimum delay length, so that the lengths of the delay lines form a sequence of unequal differences when they are arranged from small to large; where the wavelength The selection unit includes: a first allocator, which is configured to select M wavelength channels closest to the wavelength channel to be measured from the wavelength channels contained in each transmitter, and divide each selected transmitter The M wavelength channels of are assigned to the M delay lines in one-to-one correspondence, and the second distributor is configured to distribute the remaining wavelength channels to the M delay lines as equally as possible, and make the Any two wavelength channels with a wavelength difference of NΔλ are not allocated to the same delay line.

The above-mentioned wavelength selection unit and dense wavelength division multiplexing transmission experiment system have the same advantages as the corresponding method.

In addition, the embodiments of the present invention also provide a computer program for implementing the method.

In addition, embodiments of the present invention also provide at least a computer program product in the form of a computer-readable medium, on which computer program codes for implementing the above method are recorded.

Description of drawings

The present invention can be better understood by referring to the following description given in conjunction with the accompanying drawings. The accompanying drawings, together with the following detailed description, are incorporated in and form a part of this specification, and serve to further illustrate preferred embodiments of the invention and explain the principles and advantages of the invention. In the attached picture:

Fig. 1 shows a schematic structural diagram of a dense wavelength division multiplexing transmission experimental system according to an embodiment of the present invention;

FIG. 2 shows a flowchart of a method for allocating wavelength channels of a transmitter to a delay line according to an embodiment of the present invention;

FIG. 3 shows a flowchart of a method for determining the length of a delay line according to an embodiment of the present invention;

FIG. 4 shows a flowchart of a method for decorrelating channels according to an embodiment of the present invention;

FIG. 5 shows a schematic structural diagram of a wavelength selection unit according to an embodiment of the present invention;

Fig. 6 shows the effect of the channel decorrelation apparatus and method according to the present invention; and

Fig. 7 shows a schematic block diagram of a computer that can be used to implement embodiments according to the present invention.

Detailed ways

Exemplary embodiments of the present invention will be described below with reference to the accompanying drawings. In the interest of clarity and conciseness, not all features of an actual implementation are described in this specification. However, it should be understood that many implementation-specific decisions must be made in developing any such practical implementation in order to achieve the developer's specific goals, and that these decisions may vary from implementation to implementation . Moreover, it should also be understood that development work, while potentially complex and time-consuming, would at least be a routine undertaking for those skilled in the art having the benefit of this disclosure.

Here, it should also be noted that, in order to avoid obscuring the present invention due to unnecessary details, only the device structure closely related to the solution according to the present invention is shown in the drawings, and the relationship with the present invention is omitted. Little other details.

first embodiment

Fig. 1 shows a schematic structural diagram of a dense wavelength division multiplexing transmission experimental system 10 according to an embodiment of the present invention. In this experimental system, it is necessary to distribute the wavelength channel of the transmitter to a plurality of delay lines to realize decorrelation of these wavelength channels. The basic principle of the experimental system is that after the information sequences on different wavelength channels sent by the transmitter pass through different delay lines with sufficient length, these information sequences can be considered to be independent of each other.

As can be seen from FIG. 1, the experimental system 10 includes N transmitters 110, N×M couplers 120 and M delay lines 130, where N and M are natural numbers. Each transmitter includes multiple wavelength channels. For example, the wavelengths of the wavelength channels included in transmitter #1 are λ ₁ , λ _N+1 , ..., λ _kN+1 , and the wavelengths of the wavelength channels included in transmitter #2 are λ ₂ , λ _{N +2} , ..., λ _kN+2 , etc., where the wavelength difference between adjacent wavelength channels is Δλ, that is, the wavelength difference between λ _i and λ _i+1 is Δλ. In order to make optimal use of the resources of the experimental system, it is preferred that the different transmitters 110 have the same number of channels, or if the same number of channels cannot be achieved, the number of channels differs from each other by at most one. In the system proposed by the present invention, it is assumed that each transmitter 110 includes at least M wavelength channels, because if the number of wavelength channels included in the transmitter is less than M, those skilled in the art can easily imagine that in order to realize the For the de-correlation between them, these wavelength channels are allocated to different delay lines.

Under the assumption that each transmitter 110 comprises at least M wavelength channels, a method for allocating the wavelength channels of the transmitters to delay lines is proposed according to the invention. FIG. 2 shows a flowchart of a method for allocating wavelength channels of a transmitter to delay lines according to an embodiment of the present invention.

As can be seen from Figure 2, the method includes:

The first allocation step S210: select the M wavelength channels closest to the wavelength channel to be measured from the wavelength channels included in each transmitter 110, and select the M wavelength channels of each transmitter one by one Correspondingly assigned to M delay lines. For example, assuming _that the corresponding wavelength of the wavelength channel to be measured is λ ₀ , the difference between the wavelengths λ ₁ , λ _{N +1 ,} . And therefrom, M wavelengths with the smallest absolute values of differences are determined, and the wavelength channels corresponding to these wavelengths are assigned to the M delay lines in a one-to-one correspondence. Here, a one-to-one correspondence means that two channels of the same transmitter cannot be assigned to the same delay line. Likewise, this first allocation step is performed for all transmitters #1 to #N, thereby allocating N*M channels closest to the wavelength of the measurement channel to the delay line. In this allocation step, the M wavelength channels transmitted by each transmitter that have the greatest influence on the wavelength channel to be measured are allocated to M delay lines respectively, thereby ensuring the de-correlation between these wavelength channels in the experiment, Improve the reliability of the experiment.

Second allocation step S220: distribute the remaining wavelength channels as many as possible to the M delay lines 130 evenly, and make any two wavelength channels with a wavelength difference of NΔλ from the same transmitter 110 not be allocated to the same delay line 130. Here, equalizing the number as much as possible means that the remaining wavelength channels are allocated to the M delay lines 130 with the same number if possible. If equal allocation is not possible, the difference in the number of allocated wavelength channels on the respective delay lines is preferably no more than one. In addition, since any two wavelength channels with a wavelength difference of NΔλ from the same transmitter 110 are not allocated to the same delay line 130, any two adjacent wavelength channels transmitted by the same transmitter 110 will not be at the same On the delay line, this further reduces the correlation between the wavelength channels within the same transmitter and improves the accuracy of the experimental results.

It should be noted that, according to an implementation form, the first distributing step may be cyclic. That is to say, after the first allocation step is performed for the first time, if the number of the remaining wavelength channels is greater than N×M, the first allocation step can be re-executed for the remaining wavelength channels, so that the additional N×M The M channels closest to the wavelength of the measurement channel are allocated to the delay line until the number of remaining wavelength channels is less than N×M, and then the second allocation step is performed. Therefore, in the present application, it can be considered that the cycle of the first distribution step is also included in the "first distribution step".

And according to another implementation form, it is not necessary to perform the first allocation step in a loop, but only execute the first allocation step once and then perform the second allocation step for all remaining wavelength channels, regardless of whether the number of remaining wavelength channels is greater than N× M. From another point of view, it can also be considered that the second allocation step can also include operations similar to the above-mentioned first allocation step when the number of remaining wavelength channels is greater than N×M, that is, the operation of the first allocation step is also Can be one of the means by which an even distribution is attempted in the second distribution step.

In addition, it should be noted that, for the above-mentioned execution process of the first allocation step and the second allocation step, the first allocation step may be performed first for each transmitter 110, and then the second allocation step is performed for each transmitter respectively. , it is also possible to first perform a first allocation step for transmitter #1, then a second allocation step, then a first allocation step, then a second allocation step, etc. for transmitter #2, etc. Does not affect the essence of the present invention.

Through the above method, any number of channels can be processed, and in particular, multi-channel transmission experiments can be performed with relatively low equipment complexity.

second embodiment

According to an embodiment of the present invention, a method for determining the delay line length in the DWDM transmission experimental system 10 is proposed. Fig. 3 shows a flowchart of a method for determining the length of a delay line according to an embodiment of the present invention.

As can be seen from Figure 3, the method includes:

Step S310: Obtain the minimum delay time τ _min . The minimum delay time τ _min can be given in advance, or can be calculated according to the following formula:

${\mathrm{<span\; class="notranslate">\; \&tau;</span>}}_{\mathrm{<span\; class="notranslate">\; min</span>}}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; i</span>}<span\; class="notranslate">\; \&times;</span>\frac{\mathrm{<span\; class="notranslate">\; 1</span>}}{{\mathrm{<span\; class="notranslate">\; f</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; i</span>}<span\; class="notranslate">\; \&times;</span>\frac{\mathrm{<span\; class="notranslate">\; 2</span>}\mathrm{<span\; class="notranslate">\; \&pi;DN\&Delta;\&lambda;</span>}}{\mathrm{<span\; class="notranslate">\; \&alpha;</span>}}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; )</span>$

where D is the fiber dispersion coefficient, N is the number of transmitters, Δλ is the wavelength difference between adjacent wavelength channels, α is the fiber attenuation coefficient, and i is a natural number, where i>3 is usually required to ensure that the minimum delay time is sufficient to achieve wavelength Channel decorrelation.

In step S320, the minimum delay length L _min is determined according to the minimum delay time τ _min . The minimum delay length can be determined according to the following formula:

${\mathrm{<span\; class="notranslate">\; L</span>}}_{\mathrm{<span\; class="notranslate">\; min</span>}}<span\; class="notranslate">\; =</span>\frac{{\mathrm{<span\; class="notranslate">\; c\&tau;</span>}}_{\mathrm{<span\; class="notranslate">\; min</span>}}}{\mathrm{<span\; class="notranslate">\; no</span>}}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 2</span>}<span\; class="notranslate">\; )</span>$

where n is the refractive index of the fiber delay line and c is the speed of light in vacuum.

Subsequently, in step S330, the corresponding length of the delay line is determined based on the minimum delay length _Lmin . A common method in the art is to use an arithmetic sequence to determine the length of the delay line. For example, one method is to design the lengths of the M delay lines as 0, L, 2L, 3L, . . . , (M-1)L. Although this design method is simple, it has the following disadvantages: the difference between the lengths of the delay lines is equal, so the position intervals of the signal pulses after passing through these delay lines are also equal, and the superposition of these signal pulses forms a certain periodicity. Signal. Similarly, when such a signal undergoes cross-phase modulation to generate phase noise, it will also make the phase noise have a certain periodicity. It is reflected in the phase noise autocorrelation function that there is a relatively large correlation peak at a non-zero point (see the peak at 40000 ps in Figure 6). However, the above characteristics do not exist in real systems. For this reason, according to the embodiments of the present invention, it is proposed that the lengths of the delay lines are arranged from small to large to form an unequal difference sequence, thereby advantageously avoiding the defects in the case of an arithmetic difference sequence, thereby being closer to the actual system .

For example, the following arithmetic sequence can be used to design the corresponding length of the delay line: the sequence formed by the difference between two adjacent items in the unequal sequence is an arithmetic sequence. For example, the sequence 0, L, 2L+d, 3L+3d, 4L+6d, ..., where d≠0. For example, d=0.1*L may be chosen. It can be seen that the difference between adjacent two items in the above sequence constitutes an arithmetic difference sequence L, L+d, L+2d, L+3d, . . . , L+(M-2)d.

According to another embodiment, the corresponding length of the delay line can be designed by using the following arithmetic difference sequence: the difference between the second item and the first item in the unequal difference sequence is greater than the minimum delay length L _min , and starting from the third item Any one of them is the sum of the previous two. For example, the sequence L, 2L+d, 3L+d, 5L+2d, 8L+3d, . . . can be used, where d≠0. For example, d=0.1*L may be chosen. The sequence is constructed based on Fibonacci sequence or Lucas sequence.

According to another embodiment, the corresponding length of the delay line can be designed by utilizing the following arithmetic difference sequence: the unequal difference sequence is constructed based on the Pell sequence. The Pell sequence is 0, 1, 2, 5, 12, 29, 70, ..., so the sequence L, 2L, 5L, 12L, 29L, 70L, ... can be used. For example, the unequal difference sequence can be constructed by multiplying the Pell sequence by the minimum delay length.

Based on the above description of the present invention, those skilled in the art can easily imagine that other unequal difference sequences can also be used to design the length of the delay line.

Since the length of the delay line is designed using the unequal difference sequence, the periodicity contained in the arithmetic difference sequence is avoided, thereby advantageously improving the decorrelation of the channels on each delay line, making the experimental system better close to the actual system .

third embodiment

According to an embodiment of the present invention, a method for decorrelating channels in a dense wavelength division multiplexing transmission experimental system is proposed. Fig. 4 shows a flowchart of a method for decorrelating channels according to an embodiment of the present invention.

As shown in Figure 4, the method includes the following steps:

S410: Provide dense wavelength division multiplexing transmission experimental system. As described above in conjunction with FIG. 1 , the experimental system 10 includes N transmitters 110 , N×M couplers 120 and M delay lines 130 , where N and M are natural numbers. Each transmitter includes multiple wavelength channels. For example, the wavelengths of the wavelength channels included in transmitter #1 are λ ₁ , λ _N+1 , ..., λ _kN+1 , and the wavelengths of the wavelength channels included in transmitter #2 are λ ₂ , λ _{N +2} , ..., λ _kN+2 , etc., where the wavelength difference between adjacent wavelength channels is Δλ, that is, the wavelength difference between λ _i and λ _i+1 is Δλ. In order to achieve optimal utilization of the resources of the experimental system, it is preferable that the number of channels of the different transmitters 110 be the same, or if the same number of channels cannot be achieved, the number of channels differs from each other by at most one. In the system proposed by the present invention, it is assumed that each transmitter 110 includes at least M wavelength channels.

In the experimental system provided in step S410, the lengths of the M delay lines 130 are determined based on the differential sequence. Regarding how to determine the length of the delay line by using the differential difference sequence, reference may be made to the second embodiment described above, which will not be repeated here.

In step S420, the wavelength channels of the transmitter are allocated to M delay lines, so as to realize channel decorrelation in the experimental system. To this end, it is preferred to use the allocation method described in the first embodiment, ie to allocate all wavelength channels to the M delay lines through the first allocation step and the second allocation step, respectively. Regarding how to allocate wavelength channels specifically, reference may be made to the first embodiment described above, which will not be repeated here.

Since the solutions proposed in the first embodiment and the second embodiment are combined in this method, it has the advantages of the solutions in the first and second embodiments at the same time.

Fourth embodiment

According to an embodiment of the present invention, a wavelength selection unit 140 for allocating wavelength channels of a transmitter to delay lines in the dense wavelength division multiplexing transmission experimental system 10 is proposed. The system 10 also includes N transmitters 110, N×M couplers 120 and M delay lines 130, each transmitter 110 includes at least M wavelength channels and the number of channels of different transmitters 110 differs by at most one, adjacent The wavelength difference between wavelength channels is Δλ, where N and M are natural numbers

FIG. 5 shows a schematic structural diagram of the wavelength selection unit 140 according to an embodiment of the present invention. As can be seen from the figure, the wavelength selection unit 140 includes a first allocator 510 configured to select the M wavelengths closest to the wavelength channel to be measured from the wavelength channels included in each transmitter 110 channels, and assign the selected M wavelength channels of each transmitter to the M delay lines in one-to-one correspondence. In addition, the wavelength selection unit 140 also includes a second allocator 520, which is configured to evenly distribute the remaining wavelength channels to the M delay lines 130 as many as possible, and make the difference between any two wavelengths from the same transmitter 110 The wavelength channels of NΔλ are not allocated to the same delay line 130 . Regarding the specific allocation process of the first allocator and the second allocator, reference may be made to the first embodiment described above, and details are not repeated here.

Through the above-mentioned wavelength selection unit, any number of channels can be processed, and in particular, multi-channel transmission experiments can be performed with relatively low equipment complexity.

fifth embodiment

According to an embodiment of the present invention, a set wavelength division multiplexing transmission experiment system is proposed, including N transmitters 110, N×M couplers 120, M delay lines 130 and wavelength selection unit 140, each transmitter 110 It includes at least M wavelength channels and the number of channels of different transmitters 110 differs by at most one, and the wavelength difference between adjacent wavelength channels is Δλ, where N and M are natural numbers. The lengths of the M delay lines 130 in the experimental system are determined based on the differential sequence. Regarding how to determine the length of the delay line by using the differential difference sequence, reference may be made to the second embodiment described above, which will not be repeated here.

The wavelength selection unit 140 in this experimental system includes a first splitter 510 and a second splitter 520 . Regarding the specific functions of these dispensers, reference can be made to the description in the fourth embodiment, which will not be repeated here.

Fig. 6 shows the effect of the channel decorrelation apparatus and method according to the present invention. In Fig. 6, the solid line represents the phase autocorrelation function with respect to time in the case of using an arithmetic sequence to determine the length of the delay line, while the dashed line represents the phase autocorrelation function with respect to time in the case of the actual system and the case of determining the length of the delay line using an arithmetic difference sequence, respectively The phase autocorrelation function of . It can be seen from Figure 6 that, in the case of an arithmetic sequence, a relatively large autocorrelation value (for example, at 40000 ps) will appear at a certain moment due to the periodic relationship contained in the arithmetic sequence, and by using this The unequal difference sequence proposed by the invention effectively suppresses this effect, thereby better simulating the effect of the actual system.

The first allocator and the second allocator in the above-mentioned wavelength selection unit can be configured by means of software, firmware, hardware or a combination thereof. Specific means or manners that can be used for configuration are well known to those skilled in the art, and will not be repeated here. In the case of realization by software or firmware, a computer having a dedicated hardware configuration (such as a general-purpose computer 700 shown in FIG. 7 ) is installed from a storage medium or a network to configure the program of the software. When the computer is installed with various programs, Capable of performing various functions, etc.

In FIG. 7 , a central processing unit (CPU) 701 executes various processes according to programs stored in a read only memory (ROM) 702 or programs loaded from a storage section 708 to a random access memory (RAM) 703 . In the RAM 703, data required when the CPU 701 executes various processing and the like is also stored as necessary. The CPU 701, ROM 702, and RAM 703 are connected to each other via a bus 704. The input/output interface 705 is also connected to the bus 704 .

The following components are connected to the input/output interface 705: an input section 706 (including a keyboard, a mouse, etc.), an output section 707 (including a display such as a cathode ray tube (CRT), a liquid crystal display (LCD), etc., and a speaker, etc.), A storage section 708 (including a hard disk, etc.), a communication section 709 (including a network interface card such as a LAN card, a modem, etc.). The communication section 709 performs communication processing via a network such as the Internet. A driver 710 may also be connected to the input/output interface 705 as needed. A removable medium 711 such as a magnetic disk, an optical disk, a magneto-optical disk, a semiconductor memory, or the like is mounted on the drive 710 as necessary, so that a computer program read therefrom is installed into the storage section 708 as necessary.

In the case of realizing the above-described series of processing by software, the programs constituting the software are installed from a network such as the Internet or a storage medium such as the removable medium 711 .

Those skilled in the art should understand that such a storage medium is not limited to the removable medium 711 shown in FIG. 7 in which the program is stored and distributed separately from the device to provide the program to the user. Examples of the removable media 711 include magnetic disks (including floppy disks (registered trademark)), optical disks (including compact disk read only memory (CD-ROM) and digital versatile disks (DVD)), magneto-optical disks (including )) and semiconductor memory. Alternatively, the storage medium may be a ROM 702, a hard disk contained in the storage section 708, or the like, in which the programs are stored and distributed to users together with devices containing them.

The invention also proposes a program product storing machine-readable instruction codes. When the instruction code is read and executed by a machine, the above-mentioned method according to the embodiment of the present invention can be executed.

Correspondingly, a storage medium for carrying the program product storing the above-mentioned machine-readable instruction codes is also included in the disclosure of the present invention. The storage medium includes, but is not limited to, a floppy disk, an optical disk, a magneto-optical disk, a memory card, a memory stick, and the like.

Finally, it should also be noted that the term "comprises", "comprises" or any other variation thereof is intended to cover a non-exclusive inclusion such that a process, method, article or apparatus comprising a set of elements includes not only those elements, but also Other elements not expressly listed, or inherent to the process, method, article, or apparatus are also included. Furthermore, without further limitations, an element defined by the phrase "comprising a..." does not preclude the presence of additional identical elements in the process, method, article, or apparatus comprising said element .

Although the embodiments of the present invention have been described in detail above with reference to the accompanying drawings, it should be understood that the above-described embodiments are only used to illustrate the present invention, rather than to limit the present invention. Various modifications and changes can be made to the above-described embodiments by those skilled in the art without departing from the spirit and scope of the present invention. Accordingly, the scope of the present invention is limited only by the appended claims and their equivalents.

It is not difficult to see from the above description that according to the embodiments of the present invention, the following solutions are provided:

Additional Note 1. A method for distributing the wavelength channel of a transmitter to a delay line in a dense wavelength division multiplexing transmission experimental system (10), wherein said system (10) includes N transmitters (110) , N×M couplers (120) and M delay lines (130), each transmitter (110) includes at least M wavelength channels and the channel numbers of different transmitters (110) differ by at most one, between adjacent wavelength channels The wavelength difference between is Δλ, wherein N, M are natural numbers, and described method comprises:

-The first allocation step: select the M wavelength channels closest to the wavelength channel to be measured from the wavelength channels included in each transmitter (110), and select the M wavelength channels of each transmitter selected assigned to the M delay lines in one-to-one correspondence, and

-Second distribution step: distribute the remaining wavelength channels as many as possible to the M delay lines (130) evenly, and make any two wavelength channels from the same transmitter (110) with a wavelength difference of NΔλ not be distributed to The same delay line (130).

Supplementary Note 2. A method for determining delay line length in dense wavelength division multiplexing transmission experimental system (10), comprising:

- get minimum delay time,

- determine the minimum delay length based on the minimum delay time, and

- Determining the corresponding lengths of the delay lines based on the minimum delay length, so that the lengths of the delay lines are arranged from small to large to form a unequal difference sequence.

Supplement 3. The method according to Supplement 2, wherein the sequence formed by the difference between adjacent two terms in the unequal difference sequence is an arithmetic difference sequence.

Additional note 4. The method according to additional note 2, wherein the difference between the second item and the first item in the unequal difference sequence is greater than the minimum delay length, and any item starting from the third item is its The sum of the previous two items.

Supplement 5. The method according to Supplement 2, wherein the inequality sequence is constructed based on Fibonacci sequence or Lucas sequence.

Supplement 6. The method according to Supplement 2, wherein the unequal difference sequence is constructed by multiplying the Pell sequence by the minimum delay length.

Additional note 7. A method for decorrelating channels in a dense wavelength division multiplexing transmission experimental system, comprising:

-provide dense wavelength division multiplexing transmission experiment system, wherein said system comprises N transmitters (110), N*M coupler (120) and M delay lines (130), each transmitter (110) comprises at least M wavelength channels and the number of channels of different transmitters (110) differ by at most one, and the wavelength difference between adjacent wavelength channels is Δλ, where N and M are natural numbers, and

- assigning the wavelength channels of the transmitter (110) to M delay lines (130);

Wherein the lengths of the M delay lines are determined by the following method:

- get minimum delay time,

- determine the minimum delay length according to the minimum delay time,

-determine the corresponding lengths of the M delay lines (130) based on the minimum delay length, so that the lengths of the delay lines form a unequal difference sequence when arranged from small to large;

Wherein the steps of distributing the wavelength channels of the transmitter (110) to the M delay lines (130) include:

-The first allocation step: select the M wavelength channels closest to the wavelength channel to be measured from the wavelength channels included in each transmitter (110), and select the M wavelength channels of each transmitter selected assigned to the M delay lines in one-to-one correspondence, and

-Second distribution step: distribute the remaining wavelength channels as many as possible to the M delay lines (130) evenly, and make any two wavelength channels from the same transmitter (110) with a wavelength difference of NΔλ not be distributed to The same delay line (130).

Supplement 8. The method according to Supplement 7, wherein the sequence formed by the difference between adjacent two items in the unequal difference sequence is an arithmetic difference sequence.

Additional note 9. The method according to additional note 7, wherein the difference between the second item and the first item in the unequal difference sequence is greater than the minimum delay length, and any item starting from the third item is its The sum of the previous two items.

Supplement 10. The method according to Supplement 7, wherein the inequality sequence is constructed based on Fibonacci sequence or Lucas sequence.

Supplement 11. The method according to Supplement 7, wherein the unequal difference sequence is constructed by multiplying the Pell sequence by the minimum delay length.

Supplementary note 12. A wavelength selection unit (140) for distributing the wavelength channel of the transmitter to the delay line in the dense wavelength division multiplexing transmission experimental system (10), wherein the system (10) also includes N transmitters (110), N×M couplers (120) and M delay lines (130), each transmitter (110) includes at least M wavelength channels and the channel numbers of different transmitters (110) differ by at most one , the wavelength difference between adjacent wavelength channels is Δλ, where N and M are natural numbers, and the wavelength selection unit (140) includes:

- a first allocator (510), which is configured to select M wavelength channels closest to the wavelength channel to be measured from the wavelength channels included in each transmitter (110), and divide each of the selected The M wavelength channels of the transmitters are assigned to the M delay lines in one-to-one correspondence, and

- a second splitter (520), which is configured to evenly distribute the remaining wavelength channels as many as possible to the M delay lines (130), and make the difference between any two wavelengths from the same transmitter (110) be The wavelength channels of NΔλ are not allocated to the same delay line (130).

Additional note 13. A dense wavelength division multiplexing transmission experimental system, comprising N transmitters (110), N×M couplers (120), M delay lines (130) and wavelength selection units (140), each The transmitter (110) includes at least M wavelength channels and the number of channels of different transmitters (110) differs by at most one, and the wavelength difference between adjacent wavelength channels is Δλ, where N and M are natural numbers,

Wherein the lengths of the M delay lines are determined by the following method:

- get minimum delay time,

- determine the minimum delay length according to the minimum delay time,

-determine the corresponding lengths of the M delay lines (130) based on the minimum delay length, so that the lengths of the delay lines form a unequal difference sequence when arranged from small to large;

Wherein the wavelength selection unit (140) includes:

- a first allocator (510), which is configured to select M wavelength channels closest to the wavelength channel to be measured from the wavelength channels included in each transmitter (110), and divide each of the selected The M wavelength channels of the transmitters are allocated to the M delay lines one by one, and

- a second splitter (520), which is configured to evenly distribute the remaining wavelength channels as many as possible to the M delay lines (130), and make the difference between any two wavelengths from the same transmitter (110) be The wavelength channels of NΔλ are not allocated to the same delay line (130).

Supplement 14. The system according to Supplement 13, wherein the sequence formed by the difference between adjacent two items in the unequal difference sequence is an arithmetic difference sequence.

Additional note 15. The system according to additional note 13, wherein the difference between the second item and the first item in the unequal difference sequence is greater than the minimum delay length, and any item starting from the third item is its The sum of the previous two items.

Supplement 16. The system according to Supplement 13, wherein the inequality sequence is constructed based on Fibonacci sequence or Lucas sequence.

Supplement 17. The system according to Supplement 13, wherein the inequality sequence is constructed by multiplying the Pell sequence by the minimum delay length.

Supplement 18. A program product, the program product includes machine-executable instructions, and when the instructions are executed on an information processing device, the instructions cause the information processing device to execute the method described in Supplement 1 or 2. method.

Supplementary Note 19. A storage medium, the storage medium includes machine-readable program code, and when the program code is executed on an information processing device, the program code causes the information processing device to execute the program described in Supplementary Note 1 or 2. the method described.

Claims (2)

1. A method for channel decorrelation in DWDM transmission experimental system, comprising: -provide dense wavelength division multiplexing transmission experiment system, wherein said system comprises N transmitters (110), N*M coupler (120) and M delay lines (130), each transmitter (110) comprises at least M wavelength channels and the number of channels of different transmitters (110) differ by at most one, and the wavelength difference between adjacent wavelength channels is Δλ, where N and M are natural numbers, and - assigning the wavelength channels of the transmitter (110) to M delay lines (130); Wherein the lengths of the M delay lines are determined by the following method: - get minimum delay time, - determine the minimum delay length according to the minimum delay time, -determine the corresponding lengths of the M delay lines (130) based on the minimum delay length, so that the lengths of the delay lines form a unequal difference sequence when arranged from small to large; Wherein the steps of distributing the wavelength channels of the transmitter (110) to the M delay lines (130) include: -The first allocation step: select the M wavelength channels closest to the wavelength channel to be measured from the wavelength channels included in each transmitter (110), and select the M wavelength channels of each transmitter selected assigned to the M delay lines in one-to-one correspondence, and -Second distribution step: distribute the remaining wavelength channels as many as possible to the M delay lines (130) evenly, and make any two wavelength differences from the same transmitter (110) that are NΔλ wavelength channels not to be distributed to the same delay line (130), where, The unequal difference sequence is one of the following: the sequence formed by the difference between two adjacent items in the unequal difference sequence is an arithmetic difference sequence, the second item and the first item in the unequal difference sequence The difference is greater than the minimum delay length and any item starting from the third item is the sum of the previous two items, the unequal difference sequence is constructed based on the Fibonacci sequence or the Lucas sequence, and the The arithmetic sequence is constructed by multiplying the Pell sequence by the minimum delay length. 2. A dense wavelength division multiplexing transmission experimental system, comprising N transmitters (110), N×M couplers (120), M delay lines (130) and wavelength selection unit (140), each transmitter (110) includes at least M wavelength channels and the number of channels of different transmitters (110) differs by at most one, and the wavelength difference between adjacent wavelength channels is Δλ, wherein N and M are natural numbers, Wherein the lengths of the M delay lines are determined by the following method: - get minimum delay time, - determine the minimum delay length according to the minimum delay time, -determine the corresponding lengths of the M delay lines (130) based on the minimum delay length, so that the lengths of the delay lines form a unequal difference sequence when arranged from small to large; Wherein the wavelength selection unit (140) includes: - a first allocator (510), which is configured to select M wavelength channels closest to the wavelength channel to be measured from the wavelength channels included in each transmitter (110), and divide each of the selected The M wavelength channels of the transmitters are allocated to the M delay lines one by one, and - a second splitter (520), which is configured to evenly distribute the remaining wavelength channels as many as possible to the M delay lines (130), and make the difference between any two wavelengths from the same transmitter (110) be The wavelength channels of NΔλ are not allocated to the same delay line (130), where The unequal difference sequence is one of the following: the sequence formed by the difference between two adjacent items in the unequal difference sequence is an arithmetic difference sequence, the second item and the first item in the unequal difference sequence The difference is greater than the minimum delay length and any item starting from the third item is the sum of the previous two items, the unequal difference sequence is constructed based on the Fibonacci sequence or the Lucas sequence, and the The arithmetic sequence is constructed by multiplying the Pell sequence by the minimum delay length.