CN110572347B - Carrier phase compensation method and system for 128-system quadrature amplitude modulation signal - Google Patents

Carrier phase compensation method and system for 128-system quadrature amplitude modulation signal Download PDF

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CN110572347B
CN110572347B CN201910858005.0A CN201910858005A CN110572347B CN 110572347 B CN110572347 B CN 110572347B CN 201910858005 A CN201910858005 A CN 201910858005A CN 110572347 B CN110572347 B CN 110572347B
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CN110572347A (en
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刘玉民
张雨虹
张斌
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Tangshan University
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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
    • H04B10/60—Receivers
    • H04B10/61—Coherent receivers
    • H04B10/612—Coherent receivers for optical signals modulated with a format different from binary or higher-order PSK [X-PSK], e.g. QAM, DPSK, FSK, MSK, ASK
    • 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
    • H04B10/613—Coherent receivers including phase diversity, e.g., having in-phase and quadrature branches, as in QPSK coherent receivers
    • 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
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L27/00—Modulated-carrier systems
    • H04L27/32—Carrier systems characterised by combinations of two or more of the types covered by groups H04L27/02, H04L27/10, H04L27/18 or H04L27/26
    • H04L27/34—Amplitude- and phase-modulated carrier systems, e.g. quadrature-amplitude modulated carrier systems
    • H04L27/3405—Modifications of the signal space to increase the efficiency of transmission, e.g. reduction of the bit error rate, bandwidth, or average power
    • H04L27/3444—Modifications of the signal space to increase the efficiency of transmission, e.g. reduction of the bit error rate, bandwidth, or average power by applying a certain rotation to regular constellations
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L27/00—Modulated-carrier systems
    • H04L27/32—Carrier systems characterised by combinations of two or more of the types covered by groups H04L27/02, H04L27/10, H04L27/18 or H04L27/26
    • H04L27/34—Amplitude- and phase-modulated carrier systems, e.g. quadrature-amplitude modulated carrier systems
    • H04L27/36—Modulator circuits; Transmitter circuits
    • H04L27/366—Arrangements for compensating undesirable properties of the transmission path between the modulator and the demodulator
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L27/00—Modulated-carrier systems
    • H04L27/32—Carrier systems characterised by combinations of two or more of the types covered by groups H04L27/02, H04L27/10, H04L27/18 or H04L27/26
    • H04L27/34—Amplitude- and phase-modulated carrier systems, e.g. quadrature-amplitude modulated carrier systems
    • H04L27/38—Demodulator circuits; Receiver circuits
    • H04L27/3845—Demodulator circuits; Receiver circuits using non - coherent demodulation, i.e. not using a phase synchronous carrier
    • H04L27/3854—Demodulator circuits; Receiver circuits using non - coherent demodulation, i.e. not using a phase synchronous carrier using a non - coherent carrier, including systems with baseband correction for phase or frequency offset
    • H04L27/3872—Compensation for phase rotation in the demodulated signal

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Abstract

The invention discloses a carrier phase compensation method and a carrier phase compensation system for a 128-system quadrature amplitude modulation signal. Firstly, rotating the IV-type signal, the IX-type signal and the XIII-type signal in a 128-system quadrature amplitude modulation signal sequence by pi/4 radians in the same direction and carrying out normalization processing on the I-type signal, the III-type signal, the V-type signal, the VIII-type signal, the XI-type signal, the XII-type signal and the XVI-type signal, and carrying out zero setting processing on the II-type signal, the VI-type signal, the VII-type signal, the X-type signal, the XIV-type signal and the XV-type signal to obtain a preprocessed modulation signal sequence. And determining the carrier phase estimation value of each element in the received signal sequence by adopting a moving average method according to the preprocessed modulation signal sequence, and further carrying out carrier phase compensation on the received signal sequence. The carrier phase compensation method and the carrier phase compensation system have the advantages of large line width tolerance of the laser, strong practicability and good application prospect.

Description

Carrier phase compensation method and system for 128-system quadrature amplitude modulation signal
Technical Field
The present invention relates to the field of coherent optical communication systems, and in particular, to a carrier phase compensation method and system for 128-ary quadrature amplitude modulation signals.
Background
A128-system quadrature amplitude modulation (128-QAM) coherent optical communication system is very likely to become an optical communication system with the next generation data rate of 400Gb/s to 1 Tb/s. This is mainly because the system has higher spectral efficiency and channel capacity than transmission systems under the former Quadrature Phase Shift Keying (QPSK), 16-QAM, 32-QAM and 64-QAM modulation formats. Carrier phase compensation is an important component in a digital coherent receiver and is mainly used for compensating phase noise caused by laser line width.
Due to the particularity of the constellation diagram of the 128-QAM system, few high-performance carrier phase estimation methods are available. The more classical 128-QAM system carrier phase estimation method is based on the Viterbi and Viterbi (V & V) M power method of QPSK segmentation. However, the laser linewidth tolerance of the method is small, and the application of the method is limited to a certain extent.
Disclosure of Invention
The invention aims to provide a carrier phase compensation method and a carrier phase compensation system for a 128-system quadrature amplitude modulation signal, and the laser has large line width tolerance and strong practicability.
In order to achieve the purpose, the invention provides the following scheme:
a carrier phase compensation method for a 128 quadrature amplitude modulated signal, the carrier phase compensation method comprising:
obtaining a received 128-ary quadrature amplitude modulation signal sequence, wherein the 128-ary quadrature amplitude modulation signal sequence comprises: class I signals, class II signals, class III signals, class IV signals, class V signals, class VI signals, class VII signals, class VIII signals, class IX signals, class X signals, class XI signals, class XII signals, class XIII signals, class XIV signals, class XV signals, and class XVI signals;
rotating the IV-type signal, the IX-type signal and the XIII-type signal by pi/4 radians in the same direction and carrying out normalization processing, carrying out normalization processing on the I-type signal, the III-type signal, the V-type signal, the VIII-type signal, the XI-type signal, the XII-type signal and the XVI-type signal, and carrying out zero setting processing on the II-type signal, the VI-type signal, the VII-type signal, the X-type signal, the XIV-type signal and the XV-type signal to obtain a preprocessed modulation signal sequence;
determining a carrier phase estimation value of each element in the received 128-system quadrature amplitude modulation signal sequence by adopting a moving average method according to the preprocessed modulation signal sequence;
and carrying out carrier phase compensation on the 128-system quadrature amplitude modulation signal sequence according to each carrier phase estimation value.
Optionally, the determining, according to the preprocessed modulation signal sequence, a carrier phase estimation value of each element in the received 128-ary qam signal sequence by using a moving average method specifically includes:
according to the formula:
Figure BDA0002198811680000021
determining a carrier phase estimation value of each element in the 128-system quadrature amplitude modulation signal sequence; wherein the content of the first and second substances,
Figure BDA0002198811680000022
represents a carrier phase estimate for an nth element of a 128-ary quadrature amplitude modulation signal sequence, N being an odd number, N representing a moving average window length,
Figure BDA0002198811680000023
representing a pre-processed modulated signal sequence
Figure BDA0002198811680000027
The nth element in (1), n representing the element number.
Optionally, the performing carrier phase compensation on the 128-ary qam signal sequences according to each carrier phase estimation value specifically includes:
according to the formula:
Figure BDA0002198811680000024
performing carrier phase compensation on each element in the 128-ary quadrature amplitude modulation signal sequence; wherein S isnRepresenting the nth element of the received 128-ary quadrature amplitude modulated signal sequence S,
Figure BDA0002198811680000025
representing a carrier phase compensated signal sequence
Figure BDA0002198811680000026
The nth element in (1), e represents a natural constant, and j represents an imaginary unit.
A carrier phase compensation system for a 128 quadrature amplitude modulated signal, the carrier phase compensation system comprising:
a signal sequence obtaining module, configured to obtain a received 128-ary qam signal sequence, where the 128-ary qam signal sequence includes: class I signals, class II signals, class III signals, class IV signals, class V signals, class VI signals, class VII signals, class VIII signals, class IX signals, class X signals, class XI signals, class XII signals, class XIII signals, class XIV signals, class XV signals, and class XVI signals;
a preprocessing module, configured to rotate the class IV signal, the class IX signal, and the class XIII signal by pi/4 radians in the same direction and perform normalization processing, perform normalization processing on the class I signal, the class III signal, the class V signal, the class VIII signal, the class XI signal, the class XII signal, and the class XVI signal, and perform zero setting processing on the class II signal, the class VI signal, the class VII signal, the class X signal, the class XIV signal, and the class XV signal to obtain a preprocessed modulation signal sequence;
a carrier phase estimation module, configured to determine, according to the preprocessed modulation signal sequence, a carrier phase estimation value of each element in the received 128-ary qam signal sequence by using a moving average method;
and the carrier phase compensation module is used for carrying out carrier phase compensation on the 128-system quadrature amplitude modulation signal sequence according to each carrier phase estimation value.
According to the specific embodiment provided by the invention, the invention discloses the following technical effects:
the invention provides a carrier phase estimation method and a carrier phase estimation system for 128-system quadrature amplitude modulation signals, which are characterized in that firstly, IV-type signals, IX-type signals and XIII-type signals in a received 128-system quadrature amplitude modulation signal sequence are rotated by pi/4 radians in the same direction and are normalized, only the normalization processing is carried out on the I-type signals, III-type signals, V-type signals, VIII-type signals, XI-type signals, XII-type signals and XVI-type signals, and the zero setting processing is carried out on the II-type signals, VI-type signals, VII-type signals, X-type signals, XIV-type signals and XV-type signals, so that a preprocessed modulation signal sequence is obtained. And on the basis, according to the preprocessed modulation signal sequence, determining the carrier phase estimation value of each element in the 128-system quadrature amplitude modulation signal sequence by adopting a moving average method. And finally, carrying out carrier phase compensation on the received 128-system quadrature amplitude modulation signal sequence according to the estimated value of the carrier phase. The carrier phase compensation method and the carrier phase compensation system have the advantages of large line width tolerance of the laser, strong practicability and good application prospect.
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In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings needed to be used in the embodiments will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings without inventive exercise.
Fig. 1 is a flowchart of a carrier phase compensation method for 128-ary qam signals according to an embodiment of the present invention;
fig. 2 is a block diagram of a carrier phase compensation system for 128-ary qam signals according to an embodiment of the present invention;
FIG. 3 is a 128-QAM constellation;
FIG. 4 is a graph of SNR cost at a BER of 1E-2 for different sliding average window lengths N and joint linewidth symbol duration products Δ ν · T provided by an embodiment of the present invention;
fig. 5 is a graph of the required SNR versus Δ ν · T at a BER of 1E-2 according to an embodiment of the present invention.
Detailed Description
The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
The invention aims to provide a carrier phase compensation method and a carrier phase compensation system for a 128-system quadrature amplitude modulation signal, and the laser has large line width tolerance and strong practicability.
In order to make the aforementioned objects, features and advantages of the present invention comprehensible, embodiments accompanied with figures are described in further detail below.
Fig. 1 is a flowchart of a carrier phase compensation method for a 128-ary qam signal according to an embodiment of the present invention. As shown in fig. 1, the carrier phase compensation method includes:
step 101: obtaining a received 128-ary quadrature amplitude modulation signal sequence, wherein the 128-ary quadrature amplitude modulation signal sequence comprises: class I signals, class II signals, class III signals, class IV signals, class V signals, class VI signals, class VII signals, class VIII signals, class IX signals, class X signals, class XI signals, class XII signals, class XIII signals, class XIV signals, class XV signals, and class XVI signals;
step 102: rotating the IV-type signal, the IX-type signal and the XIII-type signal by pi/4 radians in the same direction and carrying out normalization processing, carrying out normalization processing on the I-type signal, the III-type signal, the V-type signal, the VIII-type signal, the XI-type signal, the XII-type signal and the XVI-type signal, and carrying out zero setting processing on the II-type signal, the VI-type signal, the VII-type signal, the X-type signal, the XIV-type signal and the XV-type signal to obtain a preprocessed modulation signal sequence;
step 103: determining a carrier phase estimation value of each element in the received 128-system quadrature amplitude modulation signal sequence by adopting a moving average method according to the preprocessed modulation signal sequence;
step 104: and carrying out carrier phase compensation on the 128-system quadrature amplitude modulation signal sequence according to each carrier phase estimation value.
Specifically, the step 103: determining a carrier phase estimation value of each element in the received 128-ary quadrature amplitude modulation signal sequence by adopting a moving average method according to the preprocessed modulation signal sequence, specifically comprising:
according to the formula:
Figure BDA0002198811680000051
determining a carrier phase estimation value of each element in the 128-system quadrature amplitude modulation signal sequence; wherein the content of the first and second substances,
Figure BDA0002198811680000052
represents a carrier phase estimate for an nth element of a 128-ary quadrature amplitude modulation signal sequence, N being an odd number, N representing a moving average window length,
Figure BDA0002198811680000053
representing a pre-processed modulated signal sequence
Figure BDA0002198811680000057
The nth element in (1), n representing the element number.
Further, the step 104: performing carrier phase compensation on the 128-ary quadrature amplitude modulation signal sequence according to each carrier phase estimation value, specifically including:
according to the formula:
Figure BDA0002198811680000054
performing carrier phase compensation on each element in the 128-ary quadrature amplitude modulation signal sequence; wherein S isnRepresenting the nth element of the received 128-ary quadrature amplitude modulated signal sequence S,
Figure BDA0002198811680000055
representing a carrier phase compensated signal sequence
Figure BDA0002198811680000056
The nth element in (1), e represents a natural constant, and j represents an imaginary unit.
Fig. 2 is a block diagram of a carrier phase compensation system for 128-ary qam signals according to an embodiment of the present invention. As shown in fig. 2, the carrier phase compensation system includes:
a signal sequence obtaining module 201, configured to obtain a received 128-ary qam signal sequence, where the 128-ary qam signal sequence includes: class I signals, class II signals, class III signals, class IV signals, class V signals, class VI signals, class VII signals, class VIII signals, class IX signals, class X signals, class XI signals, class XII signals, class XIII signals, class XIV signals, class XV signals, and class XVI signals.
A preprocessing module 202, configured to rotate the class IV signal, the class IX signal, and the class XIII signal by pi/4 radians in the same direction and perform normalization processing, perform normalization processing on the class I signal, the class III signal, the class V signal, the class VIII signal, the class XI signal, the class XII signal, and the class XVI signal, and perform zero setting processing on the class II signal, the class VI signal, the class VII signal, the class X signal, the class XIV signal, and the class XV signal, so as to obtain a preprocessed modulated signal sequence.
And a carrier phase estimation module 203, configured to determine, according to the preprocessed modulation signal sequence, a carrier phase estimation value of each element in the received 128-ary qam signal sequence by using a moving average method.
A carrier phase compensation module 204, configured to perform carrier phase compensation on the 128-ary qam signal sequence according to each carrier phase estimation value.
The implementation flow of the carrier phase compensation method for the 128-system quadrature amplitude modulation signal provided by the invention is as follows:
(1) a received 128-ary quadrature amplitude modulation signal sequence is acquired.
The nth received 128-QAM signal is represented as:
Figure BDA0002198811680000061
wherein, CnFor the transmitted 128-QAM signal, the constellation diagram is as shown in fig. 3(a), L is the length of the 128-ary quadrature amplitude modulation signal sequence, n is 0,1nFor phase noise, N, caused by the combined line width of the transmitting laser and the local oscillator lasernTo describe the Amplified Spontaneous Emission (ASE) noise generated in an optical communication link, it is mathematically modeled as complex additive white gaussian noise. Laser phase noise phinThe available Wiener process is described as
Figure BDA0002198811680000071
Wherein, viIs independent and uniformly distributed random Gaussian variable with mean value of 0 and variance of sigma2The method comprises the following steps that 2 pi (delta v · T), delta v is a joint line width of a sending laser and a local oscillator laser, T is symbol duration, and delta v · T is a product of the joint line width and the symbol duration.
As shown in FIG. 3(a), 128-QAM has 128 different constellation points, which are located on 16 rings with different amplitudes
Figure BDA0002198811680000072
Figure BDA0002198811680000073
The 15 thresholds are the average of the amplitudes of the adjacent loops to classify the signal. Wherein
Figure BDA0002198811680000074
Figure BDA0002198811680000075
Figure BDA0002198811680000076
Using the threshold R in the order of magnitude from small to large1、R2、R3、R4、R5、R6、R7、R8、R9、R10、R11、R12、R13、R14And R15128-QAM signals can be classified into class I signals, class II signals, class III signals, class IV signals, class V signals, class VI signals, class VII signals, class VIII signals, class IX signals, class X signals, class XI signals, class XII signals, class XIII signals, class XIV signals, class XV signals, and class XVI signals.
(2) The 128-ary quadrature amplitude modulation signal sequence is preprocessed.
Rotating the IV type signal, the IX type signal and the XIII type signal by pi/4 radians in the same direction, such as rotating by pi/4 radians in the clockwise direction or rotating by pi/4 radians in the anticlockwise direction; retaining the class I signal, the class III signal, the class V signal, the class VIII signal, the class XI signal, the class XII signal, and the class XVI signal; the constellation diagram of the preprocessed modulation signal sequence obtained by removing the class II signal, the class VI signal, the class VII signal, the class X signal, the class XIV signal, and the class XV signal is shown in fig. 3 (b). As can be seen from fig. 3(b), all constellation points are gathered around two diagonals with a slope equal to ± 1, and the error can be regarded as noise. Thus, all signals can substantially remove the modulated data phase with a power-of-4 operation after the rotation and zeroing process.
In order to obtain better compensation effect and further improve the laser linewidth tolerance, the embodiment preprocesses the received 128-ary qam signal sequence according to equation (2):
Figure BDA0002198811680000081
wherein S isnRepresenting the nth element of the received 128-ary quadrature amplitude modulated signal sequence S,
Figure BDA0002198811680000082
representing a pre-processed modulated signal sequence
Figure BDA00021988116800000810
The nth element in (1), n representing the serial number of the element.
That is, the class IV signal, the class IX signal, and the class XIII signal are rotated by pi/4 radians in the same direction and then normalized, the class I signal, the class III signal, the class V signal, the class VIII signal, the class XI signal, the class XII signal, and the class XVI signal are normalized, and the class II signal, the class VI signal, the class VII signal, the class X signal, the class XIV signal, and the class XV signal are zeroed, thereby obtaining a preprocessed modulated signal sequence.
(3) According to the preprocessed modulation signal sequence, a moving average method is adopted to determine the carrier phase estimation value of each element in the 128-system quadrature amplitude modulation signal sequence, and the specific calculation formula is as follows:
Figure BDA0002198811680000083
wherein the content of the first and second substances,
Figure BDA0002198811680000084
represents a carrier phase estimate for an nth element of a 128-ary quadrature amplitude modulation signal sequence, N being an odd number, N representing a moving average window length,
Figure BDA0002198811680000085
representing a pre-processed modulated signal sequence
Figure BDA0002198811680000086
The nth element in (1), n representing the element number.
(4) According to the carrier phase estimation value, carrying out carrier phase compensation on the received 128-system quadrature amplitude modulation signal sequence, wherein the compensation formula is as follows:
Figure BDA0002198811680000087
wherein S isnIndicating the second of the received 128-ary QAM signal sequence SThe number of the n elements is n,
Figure BDA0002198811680000088
representing a carrier phase compensated signal sequence
Figure BDA0002198811680000089
The nth element in (1), n representing the element number.
Since the moving average window length N has an important influence on the performance of carrier phase estimation, it is necessary to obtain an optimal window length N. Considering the current optimal forward error correction coding limit, the target value of the bit error rate BER is selected to be 1E-2, and the performance of the carrier phase compensation method is further measured. When there is no phase noise in the system and carrier phase compensation is not performed, the signal-to-noise ratio SNR required to achieve BER 1E-2 is 23.09dB, and this value is used as the reference SNR.
Figure 4 shows a graph of SNR cost at BER of 1E-2 for different moving average window lengths N and joint linewidth symbol duration products Δ ν · T. At the cost of 1dB SNR, the optimal window length N in the quassiqpsk segmentation-based carrier phase compensation method proposed by the present invention should be selected to be 1101. At this time, the tolerance of the product of the duration of the joint line width symbol Δ ν · T can reach 7E-7.
Fig. 5 shows a plot of the required SNR versus Δ ν · T at a BER of 1E-2. As shown in fig. 5, the classical QPSK segmentation-based carrier phase estimation method is labeled as QPSK, the quassiqpsk segmentation-based carrier phase estimation method proposed by the present invention is labeled as quassiqpsk, and the results obtained based on QPSK segmentation and quassiqpsk segmentation are different. It should be noted that in the carrier phase recovery methods based on QPSK partitioning and QuasiQPSK partitioning, the optimal window lengths N are 3501 and 1101, respectively. At the cost of 1dB SNR, the tolerance of the combined line width symbol duration product Delta nu.T of the QPSK method and the QuasiQPSK method provided by the invention is 2.5E-7 and 7E-7 respectively. Therefore, the tolerance of delta v.T of the QuasiQPSK method provided by the invention is improved by 180% compared with the tolerance of the QPSK method.
Therefore, the carrier phase compensation method and the carrier phase compensation system for the 128-system quadrature amplitude modulation signal have the advantages of large line width tolerance of the laser and strong practicability.
The embodiments in the present description are described in a progressive manner, each embodiment focuses on differences from other embodiments, and the same and similar parts among the embodiments are referred to each other.
The principles and embodiments of the present invention have been described herein using specific examples, which are provided only to help understand the method and the core concept of the present invention; meanwhile, for a person skilled in the art, according to the idea of the present invention, the specific embodiments and the application range may be changed. In view of the above, the present disclosure should not be construed as limiting the invention.

Claims (4)

1. A carrier phase compensation method for a 128 quadrature amplitude modulated signal, the carrier phase compensation method comprising:
obtaining a received 128-ary quadrature amplitude modulation signal sequence, wherein 128 different constellation points are available in the 128-ary quadrature amplitude modulation signal sequence, and are located on 16 rings with different amplitudes, 15 thresholds are an average value of the amplitudes of adjacent rings, and are used for dividing signal categories, and the 128-ary quadrature amplitude modulation signal sequence is divided into an I-type signal, a II-type signal, a III-type signal, an IV-type signal, a V-type signal, a VI-type signal, a VII-type signal, a VIII-type signal, an IX-type signal, an X-type signal, an XI-type signal, a XII-type signal, a XIII-type signal, an XIV-type signal, an XV-type signal, and an XVI-type signal according to the order from small to large of the amplitudes;
rotating the IV-type signal, the IX-type signal and the XIII-type signal by pi/4 radians in the same direction and carrying out normalization processing, carrying out normalization processing on the I-type signal, the III-type signal, the V-type signal, the VIII-type signal, the XI-type signal, the XII-type signal and the XVI-type signal, and carrying out zero setting processing on the II-type signal, the VI-type signal, the VII-type signal, the X-type signal, the XIV-type signal and the XV-type signal to obtain a preprocessed modulation signal sequence;
determining a carrier phase estimation value of each element in the received 128-system quadrature amplitude modulation signal sequence by adopting a moving average method according to the preprocessed modulation signal sequence;
and carrying out carrier phase compensation on the 128-system quadrature amplitude modulation signal sequence according to each carrier phase estimation value.
2. The method according to claim 1, wherein the determining the carrier phase estimation value of each element in the 128-ary qam signal sequence by using a moving average method according to the pre-processed qam signal sequence comprises:
according to the formula:
Figure FDA0002652263870000011
determining a carrier phase estimation value of each element in the 128-system quadrature amplitude modulation signal sequence; wherein the content of the first and second substances,
Figure FDA0002652263870000012
represents a carrier phase estimate for an nth element of a 128-ary quadrature amplitude modulation signal sequence, N being an odd number, N representing a moving average window length,
Figure FDA0002652263870000021
representing a pre-processed modulated signal sequence
Figure FDA0002652263870000022
The nth element in (1), n representing the element number.
3. The method according to claim 2, wherein the performing carrier phase compensation on the 128-ary qam signal sequences according to each of the carrier phase estimation values specifically comprises:
according to the formula:
Figure FDA0002652263870000023
performing carrier phase compensation on each element in the 128-ary quadrature amplitude modulation signal sequence; wherein s isnRepresenting the nth element in the received 128-ary quadrature amplitude modulated signal sequence s,
Figure FDA0002652263870000024
representing a carrier phase compensated signal sequence
Figure FDA0002652263870000025
The nth element in (1), e represents a natural constant, and j represents an imaginary unit.
4. A carrier phase compensation system for a 128 quadrature amplitude modulated signal, the carrier phase compensation system comprising:
a signal sequence obtaining module, configured to obtain a received 128-ary quadrature amplitude modulation signal sequence, where 128 different constellation points are located in the 128-ary quadrature amplitude modulation signal sequence, and located on 16 rings with different amplitudes, 15 thresholds are an average value of the amplitudes of adjacent rings, and are used to divide the signal types, and the 128-ary quadrature amplitude modulation signal sequence is divided into an I-type signal, a II-type signal, a III-type signal, an IV-type signal, a V-type signal, a VI-type signal, a VII-type signal, a VIII-type signal, an IX-type signal, an X-type signal, an XI-type signal, a XII-type signal, a XIII-type signal, an XIV-type signal, an XV-type signal, and an XVI-type signal according to the order from small amplitude to large amplitude by using the thresholds;
a preprocessing module, configured to rotate the class IV signal, the class IX signal, and the class XIII signal by pi/4 radians in the same direction and perform normalization processing, perform normalization processing on the class I signal, the class III signal, the class V signal, the class VIII signal, the class XI signal, the class XII signal, and the class XVI signal, and perform zero setting processing on the class II signal, the class VI signal, the class VII signal, the class X signal, the class XIV signal, and the class XV signal to obtain a preprocessed modulation signal sequence;
a carrier phase estimation module, configured to determine, according to the preprocessed modulation signal sequence, a carrier phase estimation value of each element in the received 128-ary qam signal sequence by using a moving average method;
and the carrier phase compensation module is used for carrying out carrier phase compensation on the 128-system quadrature amplitude modulation signal sequence according to each carrier phase estimation value.
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