CN112448769A - Optical communication method, system and storage medium based on high-dimensional modulation - Google Patents

Optical communication method, system and storage medium based on high-dimensional modulation Download PDF

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CN112448769A
CN112448769A CN201910828934.7A CN201910828934A CN112448769A CN 112448769 A CN112448769 A CN 112448769A CN 201910828934 A CN201910828934 A CN 201910828934A CN 112448769 A CN112448769 A CN 112448769A
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dimensional
modulation
optical communication
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bit stream
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张良俊
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ZTE Corp
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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
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L1/00—Arrangements for detecting or preventing errors in the information received
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L1/00—Arrangements for detecting or preventing errors in the information received
    • H04L1/0001—Systems modifying transmission characteristics according to link quality, e.g. power backoff
    • H04L1/0002—Systems modifying transmission characteristics according to link quality, e.g. power backoff by adapting the transmission rate
    • H04L1/0003—Systems modifying transmission characteristics according to link quality, e.g. power backoff by adapting the transmission rate by switching between different modulation schemes
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L1/00—Arrangements for detecting or preventing errors in the information received
    • H04L1/004—Arrangements for detecting or preventing errors in the information received by using forward error control
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N7/00—Television systems
    • H04N7/22—Adaptations for optical transmission

Abstract

The embodiment of the invention provides an optical communication method, an optical communication system and a storage medium based on high-dimensional modulation, wherein the modulation dimension of the high-dimensional modulation is determined, and a target constellation point is selected; carrying out non-binary Forward Error Correction (FEC) coding on the transmitted information bit stream; mapping the encoded bit stream to the target constellation point to form a high-dimensional symbol; transmitting the modulated high-dimensional symbols; in some implementations, an optical communication system combining high-dimensional modulation and non-binary FEC is proposed, and compared with an optical communication system adopting high-order modulation and binary FEC in the related art, the optical communication system has better transmission performance, and requires a lower optical signal-to-noise ratio under the condition of the same transmission capacity.

Description

Optical communication method, system and storage medium based on high-dimensional modulation
Technical Field
The embodiments of the present invention relate to, but not limited to, the field of communications technologies, and in particular, but not limited to, an optical communication method, system, and storage medium based on high-dimensional modulation.
Background
With the increasing urgency of the development of big data, 4K video, virtual reality and the requirements of 5G bearer, the optical transmission system needs higher transmission capacity; an effective method for increasing the transmission capacity is to use a high-order modulation format, such as DP-16QAM (16 quadrature amplitude modulation), DP-64QAM, etc., to improve the spectral efficiency; however, the spectral efficiency and the power efficiency are contradictory, and when the spectral efficiency is improved by adopting a high-order modulation format, the power efficiency is reduced, that is, the distance between constellation points is reduced, so that the error rate is increased under the same signal-to-noise ratio; meanwhile, FEC (forward error correction) is a technique for increasing the reliability of data communication. In the current common communication system, binary coding is generally adopted to realize FEC; in the related art, the optical communication system adopts the traditional high-price modulation format and binary coding, and the transmission performance is low.
Disclosure of Invention
The optical communication method, the optical communication system and the storage medium based on the high-dimensional modulation mainly solve the technical problem that in the related technology, the optical communication system adopts the traditional high-price modulation format and binary coding, and has lower transmission performance.
To solve the above technical problem, an embodiment of the present invention provides an optical communication method based on high-dimensional modulation, including:
determining the modulation dimension of high-dimensional modulation, and selecting a target constellation point;
carrying out non-binary Forward Error Correction (FEC) coding on the transmitted information bit stream;
mapping the encoded bit stream to the target constellation point to form a high-dimensional symbol;
and transmitting the modulated high-dimensional symbols.
The embodiment of the invention also provides an optical communication system based on high-dimensional modulation, which comprises:
the determining module is used for determining the modulation dimension of high-dimensional modulation and selecting a target constellation point;
the coding module is used for carrying out non-binary Forward Error Correction (FEC) coding on the sent information bit stream;
a bit mapping module for mapping the encoded bit stream to the target constellation point to form a high-dimensional symbol;
and the sending module is used for sending the modulated high-dimensional symbols.
Embodiments of the present invention also provide a storage medium storing one or more programs, which are executable by one or more processors to implement at least one step of the optical communication method based on high-dimensional modulation as described above.
The invention has the beneficial effects that:
according to the optical communication method, the system and the storage medium based on the high-dimensional modulation provided by the embodiment of the invention, the modulation dimension of the high-dimensional modulation is determined, and a target constellation point is selected; carrying out non-binary Forward Error Correction (FEC) coding on the transmitted information bit stream; mapping the encoded bit stream to the target constellation point to form a high-dimensional symbol; transmitting the modulated high-dimensional symbols; in some implementations, an optical communication system combining high-dimensional modulation and non-binary FEC is proposed, and compared with an optical communication system adopting high-order modulation and binary FEC in the related art, the optical communication system has better transmission performance, and requires a lower optical signal-to-noise ratio under the condition of the same transmission capacity.
Additional features and corresponding advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention.
Drawings
Fig. 1 is a flowchart of an optical communication method based on high-dimensional modulation according to a first embodiment of the present invention;
fig. 2 is a flowchart of an optical communication method at a receiving end according to a first embodiment of the present invention;
fig. 3 is a schematic diagram of an optical communication method based on high-dimensional modulation according to a second embodiment of the present invention;
FIG. 4 is a comparison of the performance of the high-dimensional modulation and the symbol error rate SER of DP-QPSK according to the second embodiment of the present invention;
FIG. 5 is a comparison of BER performance after RS (255,239) of DP-QPSK and high-dimensional modulation according to the second embodiment of the present invention;
fig. 6 is a schematic structural diagram of an optical communication system according to a third embodiment of the present invention;
fig. 7 is a flowchart illustrating an optical communication method implemented by an optical communication system according to a fourth embodiment of the present invention;
FIG. 8 is a SER performance comparison of DP-16QAM and the high-dimensional modulation of example four of the present invention.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention more apparent, embodiments of the present invention are described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.
The first embodiment is as follows:
in the related art, the optical communication system adopts the traditional high-price modulation format and binary FEC, so that the problem of high optical signal-to-noise ratio exists; the embodiment of the invention combines high-dimensional modulation with non-binary FEC numbering, wherein the high-dimensional modulation format simultaneously applies the degrees of freedom such as orthogonal state, time slot, frequency band, polarization state and the like in the optical field to modulate data, the increased degree of freedom can maximize the minimum Euclidean distance between constellation points on the premise of not losing spectral efficiency, and further increases the power efficiency of signals, can better solve the contradiction between the spectral efficiency and the power efficiency of the existing two-dimensional modulation format, the advantage of the high-dimensional modulation is embodied on the symbol level, and compared with high-order modulation under the same signal-to-noise ratio, the symbol error rate of the high-dimensional modulation is lower, so that the method is more suitable for the non-binary FEC technology.
Referring to fig. 1, as shown in fig. 1, an optical communication method based on high-dimensional modulation according to an embodiment of the present invention includes:
s101, determining the modulation dimension of high-dimensional modulation, and selecting a target constellation point.
It can be understood that the high-dimensional modulation means that each b bits are mapped to an N-dimensional space constellation point represented by an N-dimensional vector, N amplitudes of the N-dimensional vector are respectively carried by different physical dimensions, the high-dimensional modulation format can uniformly carry out bit-symbol mapping in a multi-dimensional space, and more space-selection optimized constellation point distributions can be provided, so that a larger minimum Euclidean distance between constellation points can be ensured, and the contradiction between the spectrum efficiency and the power efficiency is better solved; in practical applications, a high-dimensional modulation with a modulation dimension N of 4 is generally adopted in a coherent optical communication system.
In the embodiment of the invention, the selected target constellation point is related to high-dimensional modulation, and the bit number contained in each symbol is firstly modulated according to the high dimensionb, determining the number M of target constellation points, wherein M is 2bE.g. the number of bits b equals 4, then 2 is determined4A target constellation point; the method comprises the following steps that M target constellation points are selected based on a ball filling theory to enable the APE (advanced Power efficiency) of high-dimensional modulation to be maximum, a plurality of possible lattice distribution modes are provided in an N-dimensional super-ball lattice, dense lattice structures arranged in different dimensional spaces are provided in the ball filling theory, points in the densely arranged lattices are selected as constellation points, the constellation point distribution is the constellation point distribution with certain spectral efficiency and the APE being maximum; for example, when the high-dimensional modulation is 4-dimensional modulation, the target constellation points selected according to the sphere packing theory are as follows:
Figure BDA0002190007760000041
wherein
Figure BDA0002190007760000042
S102, carrying out non-binary Forward Error Correction (FEC) coding on the transmitted information bit stream.
In the embodiment of the present invention, the transmitted information bit stream is encoded by using non-binary FEC, which includes, but is not limited to, RS (Reed-Solomon) code or non-binary LDPC (Low-density Parity-check) code, for example, when RS (255,239) is used, 8 bits are used as a unit for encoding. The sequence of step S101 and step S102 has no definite sequence, and may be that non-binary FEC coding is performed on the transmitted information bit stream first, then the modulation dimension of high-dimensional modulation is determined, and a target constellation point is selected.
And S103, mapping the coded bit stream to the target constellation point to form a high-dimensional symbol.
In the embodiment of the present invention, the encoded bit stream is mapped to M target constellation points according to a preset mapping rule, wherein each b bits are mapped to one symbol. It should be noted that the mapping rule in the embodiment of the present invention may be set in a customized manner, for example, when the high-dimensional modulation is 4-dimensional modulation, the mapping rule is as shown in table 1 below.
TABLE 1
S1 S2 S3 S4 Bits
2.1489 0 0 0 0000
0.7347 1.414 0 0 0001
0.7347 -1.414 0 0 0010
0.7347 0 1.414 0 0011
0.7347 0 -1.414 0 0100
0.7347 0 0 1.414 0101
0.7347 0 0 -1.414 0110
-0.6174 1 1 1 0111
-0.6174 1 1 -1 1000
-0.6174 1 -1 1 1001
-0.6174 1 -1 -1 1010
-0.6174 -1 1 1 1011
-0.6174 -1 1 -1 1100
-0.6174 -1 -1 1 1101
-0.6174 -1 -1 -1 1110
-1.6174 0 0 0 1111
The values in S1, S2, S3, and S4 in table 1 can be flexibly adjusted according to actual situations, but when designing the mapping rule, the nearest neighbor hamming distance needs to be reduced as much as possible to obtain a lower BER. In some embodiments, a final mapping with a higher error rate may be selected from multiple random mappings, or a distance mapping manner may be adopted.
And S104, transmitting the modulated high-dimensional symbol.
When a high-dimensional symbol is generated, the high-dimensional symbol needs to be modulated onto an optical carrier, and transmission is carried through N degrees of freedom; for coherent optical communication systems, 4-dimensional modulation is commonly used, and when the modulation dimension N is 4, the high-dimensional symbol is carried by using two orthogonal 4 degrees of freedom in two x and y polarizations, that is, in-phase and quadrature phases in the x polarization; the in-phase and quadrature phases of the y polarization are obtained by, for example, splitting light into x and y polarization beams by an optical splitter, modulating the x and y polarization beams by a mach-zehnder modulator, loading data information on an optical signal, combining the two polarization beams by an optical combiner, generating a signal of an in-phase and quadrature component (i.e., I, Q component) by a 90 ° phase extender for the Q component, which is a 90 ° phase difference between the two orthogonal components, and transmitting the combined signal in an optical fiber. When the modulation dimension N >4, in addition to using two orthogonal 4 degrees of freedom in two x and y polarizations, a time slot is used to carry the high-dimensional symbol, for example, a mode in which 4 degrees of freedom provided by a polarization margin are used in combination with physical dimensions such as time slot, mode, wavelength, and the like is used to carry the high-dimensional symbol.
It should be noted that, after the transmitting end sends the modulated high-dimensional symbol, the receiving end demodulates, demaps, and decodes the modulated high-dimensional symbol to obtain the information bit stream of the transmitting end, specifically, as shown in fig. 2, fig. 2 is an optical communication method of the receiving end,
s201, after the modulated high-dimensional symbol is received and data signal processing is carried out, maximum likelihood judgment is carried out on the processed high-dimensional symbol.
In the embodiment of the invention, the modulated high-dimensional symbols are subjected to data signal processing to compensate channel damage, then the processed high-dimensional symbols are judged according to a maximum likelihood judgment criterion, and the vector distance d between the received high-dimensional symbols and each constellation point is calculatedk，
Figure BDA0002190007760000061
Wherein k is 1, 2 … … M; n is the modulation dimension, riConstellation points for the received high dimensional symbols; said Sk,iFor mapping constellation points of high-dimensional symbols, e.g. line 2S in Table 12，iIncludes { S2，1，S2，2，S2，3，S2，4Determine the minimum vector distance dkCorresponding constellation point SkThe constellation point is used as the received symbol, and the minimum vector distance is assumed to be d2Then the corresponding constellation point S2Is (0.7347, 1.414,0, 0).
And S202, demapping the judged high-dimensional symbol into a bit stream.
And S203, carrying out non-binary FEC decoding on the bit stream.
The high-dimensional symbol after the judgment is a receiving symbol, the receiving symbol is demapped into a bit stream according to a corresponding mapping rule, and when the receiving symbol d2When the constellation points { S1, S2, S3, S4} are {0.7347,1.414,0,0}, as shown in table 1, demapping to 0001, performing non-binary FEC decoding on the bit stream, and performing RS (255,239) decoding to obtain the final information bit stream at the transmitting end.
In the optical communication method based on high-dimensional modulation provided by the embodiment of the invention, the number M of constellation points is determined according to the bit number b contained in each symbol, wherein M is 2b. And determining a modulation dimension N, selecting a better constellation distribution according to a sphere filling theory, and determining a constellation distribution coordinate. The transmitted information bit stream is non-binary FEC encoded, and a non-binary LDPC code or an RS code or the like may be used. The coded bit stream is mapped to constellation points according to a certain rule, each b bits are mapped to a symbol, the symbol obtained after coding is carried by N degrees of freedom for transmission, high-dimensional modulation is realized without sacrificing spectrum efficiency, and the transmission performance is better in combination with non-binary FEC, and the required optical signal-to-noise ratio is lower.
Example two:
for convenience of understanding, the embodiment of the present invention describes a high-dimensional modulation based optical communication method with a specific example, and as shown in fig. 3, the high-dimensional modulation based optical communication method includes:
s301, determining the number M of target constellation points according to the bit number b contained in each symbol of the high-dimensional modulation.
In the embodiment of the present invention, the modulation dimension N of the high-dimensional modulation is 4, the number of bits b per symbol is selected to be 4, the number of target constellation points M is selected to be 16, and the spectral efficiency of the selected high-dimensional modulation is determined
Figure BDA0002190007760000071
Consistent with the spectral efficiency of DP-QPSK.
S302, selecting M target constellation points which enable the progressive power efficiency of the high-dimensional modulation to be maximum based on a sphere filling theory.
Using the theory of ball packing, a 4-dimensional lattice is represented as
Figure BDA0002190007760000081
Selecting densely arranged lattices as constellation points with the following coordinates
Figure BDA0002190007760000082
Wherein
Figure BDA0002190007760000083
The progressive power efficiency of the 4-dimensional modulation is maximized, with a 1.11dB gain over DP-QPSK.
S303, non-binary FEC coding is performed on the transmitted information bit stream.
In the embodiment of the invention, the transmitted bit stream is subjected to non-binary FEC coding, the adopted code pattern is RS (255,239), and coding is carried out by taking 8 bits as a unit.
And S304, mapping the coded bit stream to the target constellation point to form a high-dimensional symbol.
And mapping the coded bit stream to 16 target constellation points according to a preset mapping rule, wherein each 4bits are mapped into a symbol, and the mapping rule is as shown in table 1 in the first embodiment to form high-dimensional symbols { S1, S2, S3 and S4 }.
And S305, carrying and transmitting the high-dimensional symbols by N degrees of freedom.
The high-dimensional symbols are modulated on the light field, the high-dimensional symbols S1, S2, S3 and S4 are carried by the in-phase and the quadrature phase of the x polarization and the in-phase and the quadrature phase of the y polarization respectively, and then the high-dimensional symbols are transmitted.
And S306, carrying out digital signal processing on the high-dimensional symbol at the receiving end to compensate the channel damage.
The high-dimensional symbol is coherently received at a receiving end, and the received high-dimensional symbol is subjected to data information processing such as sampling offset or orthogonality recovery, dispersion compensation, polarization demultiplexing, frequency offset estimation and compensation and the like to compensate channel damage.
And S307, judging the high-dimensional symbol according to the maximum likelihood judgment criterion.
Computing received high dimensional symbols riThe vector distance from the 16 constellation points,
Figure BDA0002190007760000091
find the minimum dkCorresponding constellation point SkIt is determined as a received symbol.
And S308, demapping the judged high-dimensional symbol into a bit stream.
The received symbols are demapped to bits according to the mapping rules in table 1.
S309, performing non-binary FEC decoding on the bit stream.
Decoding the bits according to the RS (255,239) to obtain the information bit stream at the transmitting end, as shown in fig. 4 and 5, fig. 4 and 5 compare the transmission performance of the high-dimensional modulation scheme 402 of the embodiment of the present invention with the conventional DP-QPSK401, and fig. 4 is a comparison curve of the symbol error rate SER performance without adding the non-binary FEC. Fig. 5 is a graph of BER performance after RS (255,239) is added and it can be seen that the high dimensional modulation has a significant advantage after the addition of non-binary codes.
In the embodiment of the present invention, taking high-dimensional modulation with 4bits of data b and 4N per symbol as an example, an optical communication method is described, where the spectral efficiency is consistent with that of the conventional DP-QPSK, and the transmission performance is greatly improved by combining with non-binary FEC.
Example three:
an embodiment of the present invention provides an optical communication system, as shown in fig. 6, the optical communication system includes a determining module 601, an encoding module 602, a bit mapping module 603, a sending module 604, a data signal processing module 605, a maximum likelihood determining module 606, a bit demapping module 607, and a decoding module 608. The determining module 601, the encoding module 602, the bit mapping module 603, and the sending module 604 belong to the same transmitting end, and the data signal processing module 605, the maximum likelihood determining module 606, the bit demapping module 607, and the decoding module 608 belong to the same receiving end.
A determining module 601, configured to determine a modulation dimension of high-dimensional modulation, and select a target constellation point; the high-dimensional modulation means that each b bit is mapped to an N-dimensional space constellation point represented by an N-dimensional vector, firstly, the number M of target constellation points is determined according to the bit number b contained in each symbol of the high-dimensional modulation, and M is 2bAnd the dense lattice structures arranged in different dimensional spaces are provided in the ball filling wheel, and points in the densely arranged lattices are selected as constellation points based on a ball filling theory, so that the APE of high-dimensional adjustment is maximum.
An encoding module 602, configured to perform non-binary forward error correction FEC encoding on the transmitted information bit stream; the advantage of the high-dimensional modulation is that at the symbol level, the symbol error rate of the high-dimensional modulation is lower under the same signal-to-noise ratio, so that it is more suitable for the non-binary FEC technology, and therefore, the encoding module encodes the transmitted information bit stream by non-binary FEC encoding, including but not limited to RS code or non-binary LDPC code, and when the RS code includes but is not limited to RS (255,239), the RS code is encoded in 8-bit units.
A bit mapping module 603, configured to map the encoded bit stream to the target constellation point to form a high-dimensional symbol; the mapping rule of mapping the bit stream to the target constellation point can be set in a self-defined mode, wherein each b bit is mapped into a symbol, and when the mapping rule is designed, the nearest neighbor Hamming distance needs to be reduced as much as possible so as to obtain a lower bit error rate BER.
A sending module 604, configured to send the modulated high-dimensional symbol, where when the high-dimensional symbol is generated, the high-dimensional symbol needs to be modulated onto an optical carrier, and transmission is carried through N degrees of freedom; and when the modulation dimension N is 4, the high-dimensional symbol is carried by adopting two orthogonal 4 degrees of freedom on two x and y polarizations, and when the modulation dimension N is greater than 4, the high-dimensional symbol is carried by adopting a time slot except for adopting two orthogonal 4 degrees of freedom on two x and y polarizations.
A data signal processing module 605, configured to perform data signal processing on the received modulated high-dimensional symbol; data signal processing includes, but is not limited to, sample offset or orthogonality recovery, dispersion compensation, polarization demultiplexing, frequency offset estimation and compensation, and the like.
A maximum likelihood decision module 606, configured to perform maximum likelihood decision on the high-dimensional modulation symbol; calculating the vector distance d between the received high-dimensional symbol and each constellation pointk，
Figure BDA0002190007760000101
Wherein k is 1, 2 … … M; n is the modulation dimension, riConstellation points for the received high dimensional symbols; said Sk,iDetermining a minimum vector distance d for mapping constellation points of high-dimensional symbolskCorresponding constellation point SkAnd taking the constellation point as a received symbol.
A bit demapping module 607 for demapping the decided high-dimensional symbol into a bit stream; and determining the bit stream corresponding to the received symbol according to a mapping rule for mapping the coded bit stream to the target constellation point.
A decoding module 608, configured to perform non-binary FEC decoding on the bitstream.
The embodiment of the invention provides an optical communication system combining high-dimensional modulation and non-binary FEC (forward error correction), which comprises a determining module of a transmitting end, a coding module bit mapping module and a transmitting module; compared with the traditional DP-mQAM and binary FEC optical communication system, the communication system has better transmission performance. The optical signal-to-noise ratio required by the communication system is lower under the condition of the same transmission capacity.
Example four
For convenience of understanding, an optical communication system is described in the embodiment of the present invention, and as shown in fig. 7, a flow of an optical communication method implemented by the optical communication system includes:
s701, the encoding module encodes the transmitted bit stream using an RS (255,239) encoded in units of 8 bits.
S702, a determining module determines the modulation dimension of high-dimensional modulation and selects a target constellation point.
The selected number of bits per symbol b is 8 and the modulation dimension N is 4. The spectral efficiency SE of the high-dimensional modulation selected in this way is 8/2 ═ 4bits/symbol/pol, which is consistent with the spectral efficiency of DP-16QAM, wherein a better constellation point distribution with a number of 256 in the 4-dimensional space is found according to the sphere filling theory, and since there is not a list of more constellation points, in the embodiment of the present invention, a constellation distribution called C4-256 is selected, and compared with DP-16QAM, its progressive power efficiency has a gain of 1.7 dB.
And S703, the bit mapping module maps the coded bit stream to the target constellation point to form a high-dimensional symbol.
And mapping the code word obtained after coding into a high-dimensional symbol, and mapping every 8 bits into a symbol.
S704, the sending module adopts 4 degrees of freedom to carry and transmit the modulated high-dimensional symbols.
High-dimensional symbols are modulated onto the light field, and S1, S2, S3, S4 are carried by orthogonal and polarization 4 dimensions of light, respectively, and then transmitted. In some embodiments, when the modulation dimension is greater than 4, time slots may be used to represent more degrees of freedom.
S705, the data signal processing module processes the data signal for the received modulated high-dimensional symbol
S706, the maximum likelihood judgment module calculates the vector distance between the received symbol and 256 constellation points to determine the received symbol.
Computing received high dimensional symbols riThe vector distance from the 256 constellation points,
Figure BDA0002190007760000121
find the minimum dkCorresponding constellation point SkIt is determined as a received symbol.
S707, the bit demapping module demaps the received symbols into bits.
S708, the decoding module adopts RS (255,239) to decode to obtain the information bit stream of the transmitting end.
As shown in fig. 8, fig. 8 compares the transmission performance of the high-dimensional modulation mode 801 with that of the conventional DP-16QAM 802, and it can be seen that the high-dimensional modulation C4-256 has significant advantages.
EXAMPLE five
The present embodiments also provide a storage medium including volatile or nonvolatile, removable or non-removable media implemented in any method or technology for storage of information such as computer readable instructions, data structures, computer program modules or other data. Computer-readable storage media include, but are not limited to, RAM (Random Access Memory), ROM (Read-Only Memory), EEPROM (Electrically Erasable Programmable Read-Only Memory), flash Memory or other Memory technology, CD-ROM (Compact disk Read-Only Memory), Digital Versatile Disks (DVD) or other optical disk storage, magnetic cassettes, magnetic tape, magnetic disk storage or other magnetic storage devices, or any other medium which can be used to store the desired information and which can be accessed by a computer;
the storage medium in this embodiment may be used to store one or more computer programs, and the stored one or more computer programs may be executed by a processor to implement all or part of the steps of the optical communication method based on high-dimensional modulation in the embodiments described above.
It will be apparent to those skilled in the art that all or some of the steps of the methods, systems, functional modules/units in the devices disclosed above may be implemented as software (which may be implemented in computer program code executable by a computing device), firmware, hardware, and suitable combinations thereof. In a hardware implementation, the division between functional modules/units mentioned in the above description does not necessarily correspond to the division of physical components; for example, one physical component may have multiple functions, or one function or step may be performed by several physical components in cooperation. Some or all of the physical components may be implemented as software executed by a processor, such as a central processing unit, digital signal processor, or microprocessor, or as hardware, or as an integrated circuit, such as an application specific integrated circuit.
In addition, communication media typically embodies computer readable instructions, data structures, computer program modules or other data in a modulated data signal such as a carrier wave or other transport mechanism and includes any information delivery media as known to one of ordinary skill in the art. Thus, the present invention is not limited to any specific combination of hardware and software.
The foregoing is a more detailed description of embodiments of the present invention, and the present invention is not to be considered limited to such descriptions. For those skilled in the art to which the invention pertains, several simple deductions or substitutions can be made without departing from the spirit of the invention, and all shall be considered as belonging to the protection scope of the invention.

Claims (10)

1. An optical communication method based on high-dimensional modulation, comprising:
determining the modulation dimension of high-dimensional modulation, and selecting a target constellation point;
carrying out non-binary Forward Error Correction (FEC) coding on the transmitted information bit stream;
mapping the encoded bit stream to the target constellation point to form a high-dimensional symbol;
and transmitting the modulated high-dimensional symbols.
2. The method of claim 1, wherein selecting the target constellation point comprises:
determining a target star according to the bit number b contained in each symbol of the high-dimensional modulationNumber of seats M, M being 2b；
Selecting M target constellation points that maximize the progressive power efficiency of the high-dimensional modulation based on a sphere packing theory.
3. The method for high-dimensional modulation based optical communication according to claim 1, wherein the non-binary FEC code comprises an RS code or a non-binary LDPC code.
4. The method for optical communication based on high-dimensional modulation according to claim 1, wherein the transmitting the modulated high-dimensional symbols comprises:
adopting N degrees of freedom to bear the high-dimensional symbols;
when the modulation dimension N is 4, the high-dimensional symbol is carried by two orthogonal 4 degrees of freedom on two x and y polarizations;
when N >4, the high-dimensional symbols are carried using time slots in addition to two orthogonal 4 degrees of freedom in two x, y polarizations.
5. The method for optical communication based on high-dimensional modulation according to any one of claims 1-4, wherein said transmitting said high-dimensional symbols after modulation comprises:
after receiving the modulated high-dimensional symbol and processing a data signal, carrying out maximum likelihood judgment on the processed high-dimensional modulation symbol;
demapping the decided high-dimensional symbols into a bit stream;
non-binary FEC decoding is performed on the bitstream.
6. The method for optical communication based on high-dimensional modulation according to claim 5, wherein said making maximum likelihood decisions for said high-dimensional symbols comprises:
calculating the vector distance d between the received high-dimensional symbol and each constellation pointk，
Figure FDA0002190007750000021
The k is 1, 2 … … M; n is the modulation dimension, riConstellation points for the received high dimensional symbols; said Sk,iConstellation points for mapping high-dimensional symbols;
determining the minimum dkCorresponding constellation point SkAs received symbols.
7. An optical communication system based on high-dimensional modulation, comprising:
the determining module is used for determining the modulation dimension of high-dimensional modulation and selecting a target constellation point;
the coding module is used for carrying out non-binary Forward Error Correction (FEC) coding on the sent information bit stream;
a bit mapping module for mapping the encoded bit stream to the target constellation point to form a high-dimensional symbol;
and the sending module is used for sending the modulated high-dimensional symbols.
8. The high-dimensional modulation based optical communication system of claim 7, wherein the non-binary FEC code comprises an RS code or a non-binary LDPC code.
9. The high-dimensional modulation based optical communication system according to claim 7, further comprising:
the data signal processing module is used for carrying out data signal processing on the received modulated high-dimensional symbols;
the maximum likelihood judgment module is used for carrying out maximum likelihood judgment on the high-dimensional symbols;
a bit demapping module, configured to demap the decided high-dimensional symbol into a bit stream;
a decoding module for performing non-binary FEC decoding on the bit stream.
10. A storage medium storing one or more programs, the one or more programs being executable by one or more processors to implement at least one step of the high-dimensional modulation based optical communication method as described in any one of 1 to 6 above.
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Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20120260142A1 (en) * 2011-04-11 2012-10-11 Nec Laboratories America, Inc. Four-dimensional non-binary ldpc-coded modulation schemes for ultra high-speed optical fiber communication
US20140369680A1 (en) * 2013-06-13 2014-12-18 Ciena Corporation Variable spectral efficiency optical modulation schemes
CN105359445A (en) * 2013-06-19 2016-02-24 三菱电机株式会社 Method and system for modulating data for optical communication
CN109076039A (en) * 2016-04-13 2018-12-21 索尼公司 Use the coding and modulating device of multidimensional non-uniform constellation

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN103427943A (en) * 2012-05-25 2013-12-04 华为技术有限公司 Coding modulation method and apparatus for high-order modulation, and decoding method and apparatus for high-order modulation
CN103428158B (en) * 2012-12-12 2016-08-24 上海数字电视国家工程研究中心有限公司 Digital signal transmission device, reception device and modulation, demodulation method
US9112653B2 (en) * 2013-06-19 2015-08-18 Mitsubishi Electric Research Laboratories, Inc. Method and system for modulating optical signals as high-dimensional lattice constellation points to increase tolerance to noise

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20120260142A1 (en) * 2011-04-11 2012-10-11 Nec Laboratories America, Inc. Four-dimensional non-binary ldpc-coded modulation schemes for ultra high-speed optical fiber communication
US20140369680A1 (en) * 2013-06-13 2014-12-18 Ciena Corporation Variable spectral efficiency optical modulation schemes
CN105359445A (en) * 2013-06-19 2016-02-24 三菱电机株式会社 Method and system for modulating data for optical communication
CN109076039A (en) * 2016-04-13 2018-12-21 索尼公司 Use the coding and modulating device of multidimensional non-uniform constellation

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