CN116743261A - Digital subcarrier multiplexing signal equalization enhancement phase noise processing method - Google Patents

Digital subcarrier multiplexing signal equalization enhancement phase noise processing method Download PDF

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Publication number
CN116743261A
CN116743261A CN202310648647.4A CN202310648647A CN116743261A CN 116743261 A CN116743261 A CN 116743261A CN 202310648647 A CN202310648647 A CN 202310648647A CN 116743261 A CN116743261 A CN 116743261A
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phase noise
phase
receiving end
transmitting end
signal
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付松年
吕红
周概
向梦
秦玉文
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Guangdong University of Technology
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Guangdong University of Technology
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    • 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
    • H04B10/50—Transmitters
    • H04B10/516—Details of coding or modulation
    • H04B10/5165—Carrier suppressed; Single sideband; Double sideband or vestigial
    • 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
    • H04B10/50—Transmitters
    • H04B10/516—Details of coding or modulation
    • H04B10/548—Phase or frequency modulation
    • H04B10/556—Digital modulation, e.g. differential phase shift keying [DPSK] or frequency shift keying [FSK]
    • H04B10/5563—Digital frequency modulation
    • 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
    • H04B10/60—Receivers
    • H04B10/61—Coherent receivers
    • H04B10/616—Details of the electronic signal processing in coherent optical receivers
    • H04B10/6161—Compensation of chromatic dispersion
    • 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
    • H04B10/60—Receivers
    • H04B10/61—Coherent receivers
    • H04B10/616—Details of the electronic signal processing in coherent optical receivers
    • H04B10/6165—Estimation of the phase of the received optical signal, phase error estimation or phase error correction

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

Abstract

The application discloses a processing method for equalizing and enhancing phase noise of a digital subcarrier multiplexing signal, which comprises the following steps: setting a guard interval on the digital subcarrier multiplexing signal, and inserting two pilot signals with set amplitude and phase; acquiring two groups of phase noises with set time delay at a receiving end according to the phase of a pilot signal, and respectively performing signal processing on the phase noises to obtain phase noises of a transmitting end and the receiving end; reconstructing the phase noise of the transmitting end to obtain the phase noise of the transmitting end after reconstruction; reconstructing the phase noise of the receiving end to obtain the reconstructed phase noise of the receiving end; and compensating the phase noise of the receiving end before dispersion equalization, and compensating the phase noise of the transmitting end after dispersion equalization to finish the processing of the phase noise of the digital subcarrier multiplexing signal. Compared with the traditional technology, the method can avoid the generation of balanced enhancement phase noise, thereby achieving the effect of compensating the balanced enhancement phase noise.

Description

Digital subcarrier multiplexing signal equalization enhancement phase noise processing method
Technical Field
The application relates to the technical field of optical fiber communication, in particular to a processing method for equalizing and enhancing phase noise of digital subcarrier multiplexing signals.
Background
Digital Signal Processing (DSP) has been widely used in coherent optical communication systems and is capable of effectively compensating for many types of linear impairments, such as Chromatic Dispersion (CD), frequency Offset (FO), polarization-mode dispersion (PMD), etc., while fiber nonlinearity remains a determining factor limiting the transmission capacity of optical communication systems. In order to suppress fiber nonlinearities in coherent optical communication systems, existing transmission systems commonly employ Digital Subcarrier Multiplexing (DSM) technology. Compared with the traditional single carrier system, the nonlinear tolerance of the digital subcarrier multiplexing system is higher, and in addition, the digital subcarrier multiplexing system also has higher modulation flexibility.
Because of the influence of the chromatic dispersion of the signal in the optical fiber transmission, the receiving end must adopt chromatic dispersion equalization to remove the chromatic dispersion damage introduced by the optical fiber, but the phase noise of the receiving end can generate equalization enhancement phase noise after chromatic dispersion equalization, and the performance of a transmission system can be seriously deteriorated. For compensating equalization and enhancing phase noise, in 2020, awi Luo Daxue proposes a compensation algorithm based on dual reference subcarriers, and significant benefits are obtained.
The equalization enhancement phase noise compensation algorithm based on the double reference subcarriers mainly comprises the steps of inserting dense pilot symbols on the two reference subcarriers, so that more accurate phase noise is obtained after subcarrier demultiplexing and Multiple Input Multiple Output (MIMO) equalizer, subtracting and accumulating the two groups of phase noise to obtain reconstructed receiving end phase noise, subtracting the receiving end phase noise which is reconstructed after passing time delay by the two groups of phase noise to obtain reconstructed transmitting end phase noise, aligning the reconstructed receiving end phase noise according to the time delay of different subcarriers, adding the reconstructed receiving end phase noise with the reconstructed transmitting end phase noise, obtaining the phase noise of each subcarrier, and compensating the phase noise. Since the compensation algorithm based on the double reference subcarriers needs to insert dense pilot frequencies on the reference subcarriers, when the number of the subcarriers is large, the pilot frequencies are all loaded by even two reference subcarriers, so that the spectrum efficiency of the signal is more sacrificed. And there is an averaging operation when the phase noise is acquired through the pilot symbols, adding additional computational complexity.
The prior art discloses a method and system for correcting and monitoring phase noise in a coherent optical multi-carrier system with chromatic dispersion, wherein the multi-carrier system comprises an optical transmitter for transmitting two or more sub-carriers and an optical receiver for receiving said sub-carriers; wherein, the optical channel has chromatic dispersion, the laser of the transmitting end has phase noise, and the laser of the receiving end has phase noise; wherein the digital signal processing system comprises an electronic data processor configured to obtain a receiver phase noise estimate by a linear combination of the transmitter phase noise and the receiver phase noise when the linear combination is received at the receiver, and configured to obtain the transmitter phase noise estimate. The disadvantage of this scheme is that operating on two sub-carriers, using a linear combination of the transmitter phase estimate and the receiver phase estimate to correct the phase noise in each sub-carrier, requires a more complex computational process.
In view of the above needs and the drawbacks of the prior art, the present application proposes a method for processing digital subcarrier multiplexing signal equalization enhanced phase noise.
Disclosure of Invention
The application provides a processing method for equalizing and enhancing phase noise of a digital subcarrier multiplexing signal, which can compensate phase noise of a receiving end before dispersion compensation and phase noise of a transmitting end after dispersion compensation, only adopts two narrow-band guard intervals, does not sacrifice the spectrum efficiency of two subcarriers in the digital subcarrier multiplexing signal, is transparent to modulation format, and can avoid generating equalizing and enhancing phase noise, thereby achieving the effect of compensating and enhancing phase noise.
The primary purpose of the application is to solve the technical problems, and the technical scheme of the application is as follows:
the application provides a processing method for equalizing and enhancing phase noise of a digital subcarrier multiplexing signal, which comprises the following steps:
s1, setting a guard interval on a digital subcarrier multiplexing signal, and inserting two pilot signals with set amplitude and phase.
S2, acquiring two groups of phase noises with set time delay at a receiving end according to the phase of the pilot signal, and respectively performing signal processing on the phase noises to obtain the phase noises of a transmitting end and the phase noises of the receiving end.
S3, reconstructing the phase noise of the transmitting end to obtain the reconstructed phase noise of the transmitting end; and reconstructing the phase noise of the receiving end to obtain the reconstructed phase noise of the receiving end.
And S4, compensating the phase noise of the receiving end before dispersion equalization, and compensating the phase noise of the transmitting end after dispersion equalization to finish the processing of the phase noise of the digital subcarrier multiplexing signal.
Further, the phase of the pilot signal is:
wherein ,representing the phase of the pilot signal, X tone Representing the pilot signal extracted at the receiving end by digital signal processing.
Further, the step S1 specifically includes: in order to save spectrum resources, a guard interval is arranged on X polarization and Y polarization of a digital subcarrier multiplexing signal, and pilot signals are respectively inserted into the center positions of the guard interval; the protection intervals of the X polarization and the Y polarization are symmetrical, the protection interval is a set value, and the amplitude of the pilot signal is a constant.
Further, the phase noise of the transmitting end and the receiving end obtained in the step S2 is specifically:
T subcarrier CD ＝Lβ 2 Δω subcarrier
T tone CD ＝Lβ 2 Δω tone
wherein, the signal causes phase noise phi of the transmitting end at the transmitting end due to the linewidth of the laser TX Transmission through an optical fiber is affected by chromatic dispersion, resulting in phi TX Different time delays exist in different subcarriers, and the phase noise phi of the receiving end caused by the linewidth of the local oscillator laser of the receiving end LO Are identical across the various subcarriers. tone_position represents the insertion position of pilot signal, T subcarrier CD and Ttone CD Respectively representing the maximum time delay between two consecutive sub-carrier signals and a consecutive pilot signal, L representing the length of the optical fiber, Δω subcarrier Representing subcarrier bandwidth, Δω tone Indicating guard interval, beta 2 Representing the dispersion parameter, phi, of the optical fiber TX Represents phase noise of transmitting end, phi LO Representing the phase noise at the receiving end.
Further, before step S3, the transmitting end phase noise sample needs to be processed, which specifically includes: subtracting the phase noise of the transmitting end and the phase noise of the receiving end to obtain two groups of transmitting end phase noise samples phi with different time delays TX Is the difference of (2)The specific mathematical expression form is as follows:
in order to alleviate the reconstruction error caused by the phase noise change in the time delay range, the phase noise change in the time delay range is evenly divided to obtain the variation among the samples of the transmitting end, and the specific mathematical expression form is as follows:
wherein α represents the number of samples contained in the delay range, T s Is the sampling period.
Further, the process of reconstructing the phase noise of the transmitting end specifically includes: after the variation among phi TX samples is obtained, the phase noise of the reconstructed transmitting end is obtained by adopting a mode of integrating and accumulating againThe specific calculation process is as follows:
wherein ,representing a predetermined initial fixed phase value.
Further, the process of reconstructing the phase noise of the receiving end specifically includes: reconstructed transmitting end phase noiseRespectively carrying out time delay twice, and then respectively using two pilot signals +.> and />Minus delay +.>And averaging to obtain the reconstructed phase noise of the receiving end, wherein the specific mathematical expression form is as follows:
wherein ,representing the reconstructed receiver phase noise.
Further, the step S4 specifically includes: compensating the phase noise of the receiving end before the dispersion equalization of the reconstructed phase noise of the receiving end, and compensating the phase noise of the transmitting end after the dispersion equalization of the reconstructed phase noise of the transmitting end; the calculation process is as follows:
wherein ,Sre (t) is a signal received by the receiving end, h (t) is a dispersion compensation function,is a convolution symbol.
The second aspect of the present application provides a processing system for equalizing and enhancing phase noise of a digital subcarrier multiplexing signal, comprising: the device comprises a pilot signal insertion module, a phase noise acquisition module, a phase noise reconstruction module and a dispersion compensation module; the pilot signal insertion module sets a guard interval on the digital subcarrier multiplexing signal and inserts two pilot signals with set amplitude and phase; the phase noise acquisition module acquires two groups of phase noises with set time delay at the receiving end according to the phase of the pilot signal, and respectively carries out signal processing on the phase noises to obtain the phase noise of the transmitting end and the phase noise of the receiving end; the phase noise reconstruction module is used for reconstructing the phase noise of the transmitting end and the receiving end obtained by the phase noise obtaining module respectively; the dispersion compensation module compensates phase noise of the receiving end before dispersion equalization and compensates phase noise of the transmitting end after dispersion equalization.
The third aspect of the present application provides a processing device for equalizing and enhancing phase noise of a digital subcarrier multiplexing signal, which comprises a memory and a processor, wherein the memory comprises a processing program for equalizing and enhancing phase noise of the digital subcarrier multiplexing signal, and the processing program for equalizing and enhancing phase noise of the digital subcarrier multiplexing signal is executed by the processor to realize the processing method for equalizing and enhancing phase noise of the digital subcarrier multiplexing signal.
Compared with the prior art, the technical scheme of the application has the beneficial effects that:
the application provides a processing method for equalizing and enhancing phase noise of a digital subcarrier multiplexing signal, which only adopts two narrowband guard intervals, does not sacrifice the frequency spectrum efficiency of two subcarriers in the digital subcarrier multiplexing signal, and is transparent to modulation format. Two groups of phase noises with different time delays are obtained through the phases of the pilot signals, the two groups of phase noises are subjected to signal processing, and the phase noises of a transmitting end and a receiving end are respectively reconstructed. And compensating the phase noise of the receiving end before the dispersion compensation and compensating the phase noise of the transmitting end after the dispersion compensation, thereby avoiding the generation of balanced enhancement phase noise and achieving the effect of compensating the balanced enhancement phase noise.
Drawings
Fig. 1 is a flowchart of a method for processing digital subcarrier multiplexing signal equalization enhanced phase noise according to the present application.
Fig. 2 is a schematic diagram of presetting guard intervals on the X-polarization and the Y-polarization of a digital subcarrier multiplexed signal and inserting pilot signals in an embodiment of the application.
Fig. 3 is a schematic diagram of a processing system for equalizing and enhancing phase noise of a digital subcarrier multiplexed signal according to the present application.
Fig. 4 is a schematic diagram of a processing device for equalizing and enhancing phase noise of a digital subcarrier multiplexed signal according to the present application.
FIG. 5 is a schematic diagram of a simulation system according to an embodiment of the present application.
Fig. 6 is a graph showing the relationship between the transmission distance of the digital subcarrier multiplexed signal and the Q factor of the signal according to an embodiment of the present application.
Detailed Description
In order that the above-recited objects, features and advantages of the present application will be more clearly understood, a more particular description of the application will be rendered by reference to the appended drawings and appended detailed description. It should be noted that, without conflict, the embodiments of the present application and features in the embodiments may be combined with each other.
In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present application, however, the present application may be practiced in other ways than those described herein, and therefore the scope of the present application is not limited to the specific embodiments disclosed below.
Example 1
As shown in fig. 1, the application provides a processing method for equalizing and enhancing phase noise of a digital subcarrier multiplexing signal, which comprises the following steps:
s1, setting a guard interval on a digital subcarrier multiplexing signal, and inserting two pilot signals with set amplitude and phase.
In one particular embodiment, as shown in figure 2,
s2, acquiring two groups of phase noises with set time delay at a receiving end according to the phase of the pilot signal, and respectively performing signal processing on the phase noises to obtain the phase noises of a transmitting end and the phase noises of the receiving end.
S3, reconstructing the phase noise of the transmitting end to obtain the reconstructed phase noise of the transmitting end; and reconstructing the phase noise of the receiving end to obtain the reconstructed phase noise of the receiving end.
And S5, compensating the phase noise of the receiving end before dispersion equalization, and compensating the phase noise of the transmitting end after dispersion equalization to finish the processing of the phase noise of the digital subcarrier multiplexing signal.
Further, the phase of the pilot signal is:
wherein ,representing the phase of the pilot signal, X tone Representing the pilot signal extracted at the receiving end by digital signal processing.
Further, the step S1 specifically includes: in order to save spectrum resources, a guard interval is arranged on X polarization and Y polarization of a digital subcarrier multiplexing signal, and pilot signals are respectively inserted into the center positions of the guard interval; the protection intervals of the X polarization and the Y polarization are symmetrical, the protection interval is a set value, and the amplitude of the pilot signal is a constant.
Further, the phase noise of the transmitting end and the receiving end obtained in the step S2 is specifically:
T subcarrier CD ＝Lβ 2 Δω subcarrier
T tone CD ＝Lβ 2 Δω tone
wherein, the signal causes phase noise phi of the transmitting end at the transmitting end due to the linewidth of the laser TX Transmission through an optical fiber is affected by chromatic dispersion, resulting in phi TX Different time delays exist in different subcarriers, and the phase noise phi of the receiving end caused by the linewidth of the local oscillator laser of the receiving end LO Are identical across the various subcarriers. tone_position represents the insertion position of pilot signal, T subcarrier CD and Ttone CD Respectively between two consecutive sub-carrier signals and a consecutive pilot signalL represents the length of the fiber, Δω subcarrier Representing subcarrier bandwidth, Δω tone Indicating guard interval, beta 2 Representing the dispersion parameter, phi, of the optical fiber TX Represents phase noise of transmitting end, phi LO Representing the phase noise at the receiving end.
Further, before step S3, the transmitting end phase noise sample needs to be processed, which specifically includes: subtracting the phase noise of the transmitting end and the phase noise of the receiving end to obtain two groups of transmitting end phase noise samples phi with different time delays TX Is the difference of (2)The specific mathematical expression form is as follows:
in order to alleviate the reconstruction error caused by the phase noise change in the time delay range, the phase noise change in the time delay range is evenly divided to obtain the variation among the samples of the transmitting end, and the specific mathematical expression form is as follows:
wherein α represents the number of samples contained in the delay range, T s Is the sampling period.
Further, the process of reconstructing the phase noise of the transmitting end specifically includes: obtaining phi TX After the variation among samples, a mode of integrating and accumulating again is adopted to obtain the phase noise of the transmitting end after reconstructionThe specific calculation process is as follows:
wherein ,representing a predetermined initial fixed phase value.
Further, the process of reconstructing the phase noise of the receiving end specifically includes: reconstructed transmitting end phase noiseRespectively carrying out time delay twice, and then respectively using two pilot signals +.> and />Minus delay +.>And averaging to obtain the reconstructed phase noise of the receiving end, wherein the specific mathematical expression form is as follows:
wherein ,representing the reconstructed receiver phase noise.
Further, the step S4 specifically includes: compensating the phase noise of the receiving end before the dispersion equalization of the reconstructed phase noise of the receiving end, and compensating the phase noise of the transmitting end after the dispersion equalization of the reconstructed phase noise of the transmitting end; the calculation process is as follows:
wherein ,Sre (t) is a signal received by the receiving end, h (t) is a dispersion compensation function,is a convolution symbol.
Example 2
Based on the above embodiment 1, as shown in fig. 3, a second aspect of the present application provides a processing system for equalizing and enhancing phase noise of a digital subcarrier multiplexed signal, which includes: the device comprises a pilot signal insertion module, a phase noise acquisition module, a phase noise reconstruction module and a dispersion compensation module; the pilot signal insertion module sets a guard interval on the digital subcarrier multiplexing signal and inserts two pilot signals with set amplitude and phase; the phase noise acquisition module acquires two groups of phase noises with set time delay at the receiving end according to the phase of the pilot signal, and respectively carries out signal processing on the phase noises to obtain the phase noise of the transmitting end and the phase noise of the receiving end; the phase noise reconstruction module is used for reconstructing the phase noise of the transmitting end and the receiving end obtained by the phase noise obtaining module respectively; the dispersion compensation module compensates phase noise of the receiving end before dispersion equalization and compensates phase noise of the transmitting end after dispersion equalization.
As shown in fig. 4, a third aspect of the present application provides a processing device for equalizing and enhancing phase noise of a digital subcarrier multiplexing signal, which includes a memory and a processor, where the memory includes a processing program for equalizing and enhancing phase noise of a digital subcarrier multiplexing signal, and the processing program for equalizing and enhancing phase noise of a digital subcarrier multiplexing signal is executed by the processor to implement the processing method for equalizing and enhancing phase noise of a digital subcarrier multiplexing signal.
In the embodiments provided herein, it should be understood that the disclosed systems and methods can be implemented in other ways. Those of ordinary skill in the art will appreciate that: all or part of the steps for implementing the above method embodiments can be implemented by hardware associated with program instructions, and the foregoing program can be stored in a computer readable storage medium, which when executed, performs steps including the above method embodiments; and the aforementioned storage medium includes: a mobile storage device, a Read-Only Memory (ROM), a random access Memory (RAM, random Access Memory), a magnetic disk, or an optical disk, or the like, which can store program codes.
Alternatively, the above-described embodiments of the present application can be stored in a computer-readable storage medium if implemented in the form of software functional modules and sold or used as a stand-alone product. Based on such understanding, the technical solutions of the embodiments of the present application can be embodied essentially or in part contributing to the prior art in the form of a software product stored in a storage medium, comprising several instructions for causing a computer device.
All or part of the methods described in the various embodiments of the application are performed. And the aforementioned storage medium includes: a removable storage device, ROM, RAM, magnetic or optical disk, or other medium capable of storing program code.
Example 3
Based on the above embodiments 1 and 2, the present embodiment combines fig. 5 to 6 to describe the compensation benefit of the technical solution of the present application for equalizing and enhancing phase noise in detail.
In a specific embodiment, as shown in fig. 5, a digital subcarrier multiplexing signal with a baud rate of 64Gbaud is used, wherein the number of subcarriers is 8, each subcarrier adopts a dual polarization 64-order quadrature amplitude modulation (DP-64 QAM) format, and the roll-off coefficient of a root raised cosine shaping filter at the transmitting end is 0.1. The dispersion coefficient is 17ps/nm/km, the linewidth of the laser at the transmitting end and the receiving end is 100kHz, the guard interval is set to 0.5GHz for inserting pilot signals, and the optical signal-to-noise ratio is set to 25dB. The simulation system block diagram is shown in fig. 5, and the compensation of the equalization enhancement phase noise is performed as follows:
1. two sets of estimated phase noise are obtained from the amplitude pilot signal.
2. And reconstructing the phase noise of the transmitting end and the phase noise of the receiving end through the two groups of phase noise.
3. And compensating the phase noise of the receiving end before and after the dispersion equalization by using the reconstructed phase noise of the transmitting end and the reconstructed phase noise of the receiving end.
Fig. 5 is a graph of transmission distance versus Q factor under 8 subcarriers, and comparing the disclosed scheme (DT-CPE) with the conventional pilot signal compensation scheme (Tone), it can be found that the Q factor difference between the DT-CPE scheme and the conventional scheme increases with the increase of transmission distance, and the Q factor gain of the DT-CPE scheme is about 0.28dB compared with the conventional scheme under 2000km transmission, which proves that the disclosed scheme has significant compensation benefit for equalizing enhanced phase noise.
It is to be understood that the above examples of the present application are provided by way of illustration only and not by way of limitation of the embodiments of the present application. The drawings depict structural positional relationships and are merely illustrative, and are not to be construed as limiting the patent. Other variations or modifications of the above teachings will be apparent to those of ordinary skill in the art. It is not necessary here nor is it exhaustive of all embodiments. Any modification, equivalent replacement, improvement, etc. which come within the spirit and principles of the application are desired to be protected by the following claims.

Claims (10)

1. A processing method for equalizing and enhancing phase noise of a digital subcarrier multiplexing signal is characterized by comprising the following steps:
s1, setting a guard interval on a digital subcarrier multiplexing signal, and inserting two pilot signals with set amplitude and phase;
s2, acquiring two groups of phase noises with set time delay at a receiving end according to the phase of the pilot signal, and respectively performing signal processing on the phase noises to obtain the phase noises of a transmitting end and the phase noises of the receiving end;
s3, reconstructing the phase noise of the transmitting end to obtain the reconstructed phase noise of the transmitting end; reconstructing the phase noise of the receiving end to obtain the reconstructed phase noise of the receiving end;
and S4, compensating the phase noise of the receiving end before dispersion equalization, and compensating the phase noise of the transmitting end after dispersion equalization to finish the processing of the phase noise of the digital subcarrier multiplexing signal.
2. The method for processing the digital subcarrier multiplexing signal equalization enhanced phase noise as claimed in claim 1, wherein the phase of the pilot signal is:
wherein ,representing the phase of the pilot signal, X tone Representing the pilot signal extracted at the receiving end by digital signal processing.
3. The method for processing the digital subcarrier multiplexing signal equalization enhanced phase noise as claimed in claim 1, wherein the step S1 specifically comprises: setting a guard interval on X polarization and Y polarization of a digital subcarrier multiplexing signal, and respectively inserting pilot signals at the center positions of the guard intervals; the protection intervals of the X polarization and the Y polarization are symmetrical, the protection interval is a set value, and the amplitude of the pilot signal is a constant.
4. The method for processing the digital subcarrier multiplexing signal equalization enhanced phase noise as claimed in claim 3, wherein the phase noise of the transmitting end and the receiving end obtained in the step S2 is specifically:
T subcarrier CD ＝Lβ 2 Δω subcarrier
T tone CD ＝Lβ 2 Δω tone
wherein tone_position represents the insertion position of the pilot signal, T subcarrier CD and Ttone CD Respectively representing the maximum time delay between two consecutive sub-carrier signals and a consecutive pilot signal, L representing the length of the optical fiber, Δω subcarrier Representing subcarrier bandwidth, Δω tone Indicating guard interval, beta 2 Representing the dispersion parameter, phi, of the optical fiber TX Represents phase noise of transmitting end, phi LO Representing the phase noise at the receiving end.
5. The method for processing digital subcarrier multiplexing signal equalization enhanced phase noise as claimed in claim 4, wherein the processing of the transmitting end phase noise sample is required before step S3, which comprises the following specific steps: subtracting the phase noise of the transmitting end and the phase noise of the receiving end to obtain two groups of transmitting end phase noise samples phi with different time delays TX Is the difference of (2)The specific mathematical expression form is as follows:
the phase noise change in the time delay range is evenly divided, so that the change quantity among the samples of the transmitting end is obtained, and the specific mathematical expression form is as follows:
wherein α represents the number of samples contained in the delay range, T s Is the sampling period.
6. The method for processing digital subcarrier multiplexing signal equalization enhanced phase noise as defined in claim 5, wherein the process of reconstructing phase noise of the transmitting end specifically comprises: obtaining phi TX After the variation among samples, a mode of integrating and accumulating again is adopted to obtain the phase noise of the transmitting end after reconstructionThe specific calculation process is as follows:
wherein ,representing a predetermined initial fixed phase value.
7. The method for processing the digital subcarrier multiplexing signal equalization enhanced phase noise as claimed in claim 6, wherein the process of reconstructing the phase noise of the receiving end specifically comprises: reconstructed transmitting end phase noiseRespectively carrying out time delay twice, and then respectively using two pilot signals +.> and />Minus delay +.>And averaging to obtain the reconstructed phase noise of the receiving end, wherein the specific mathematical expression form is as follows:
wherein ,representing the reconstructed receiver phase noise.
8. The method for processing the digital subcarrier multiplexing signal equalization enhanced phase noise as claimed in claim 7, wherein said step S4 specifically comprises: compensating the phase noise of the receiving end before the dispersion equalization of the reconstructed phase noise of the receiving end, and compensating the phase noise of the transmitting end after the dispersion equalization of the reconstructed phase noise of the transmitting end; the calculation process is as follows:
wherein ,Sre (t) is a signal received by the receiving end, h (t) is a dispersion compensation function,is a convolution symbol.
9. A system for processing digital subcarrier multiplexed signal equalization enhanced phase noise, comprising: the device comprises a pilot signal insertion module, a phase noise acquisition module, a phase noise reconstruction module and a dispersion compensation module;
the pilot signal insertion module sets a guard interval on the digital subcarrier multiplexing signal and inserts two pilot signals with set amplitude and phase; the phase noise acquisition module acquires two groups of phase noises with set time delay at the receiving end according to the phase of the pilot signal, and respectively carries out signal processing on the phase noises to obtain the phase noise of the transmitting end and the phase noise of the receiving end; the phase noise reconstruction module is used for reconstructing the phase noise of the transmitting end and the receiving end obtained by the phase noise obtaining module respectively; the dispersion compensation module compensates phase noise of the receiving end before dispersion equalization and compensates phase noise of the transmitting end after dispersion equalization.
10. A processing device for equalizing and enhancing phase noise of a digital subcarrier multiplexing signal, comprising a memory and a processor, wherein the memory comprises a processing program for equalizing and enhancing phase noise of the digital subcarrier multiplexing signal, and the processing program for equalizing and enhancing phase noise of the digital subcarrier multiplexing signal realizes the processing method for equalizing and enhancing phase noise of the digital subcarrier multiplexing signal according to any one of claims 1-8 when being executed by the processor.
CN202310648647.4A 2023-06-01 2023-06-01 Digital subcarrier multiplexing signal equalization enhancement phase noise processing method Pending CN116743261A (en)

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