CN115242347A

CN115242347A - Signal processing method, device and equipment of wavelength division multiplexing optical transmission system

Info

Publication number: CN115242347A
Application number: CN202210824006.5A
Authority: CN
Inventors: 朱宸; 周谞; 王硕; 姜宇峰; 孙天兵; 高峰; 程钢
Original assignee: Beijing Baidu Netcom Science and Technology Co Ltd
Current assignee: Beijing Baidu Netcom Science and Technology Co Ltd
Priority date: 2022-07-13
Filing date: 2022-07-13
Publication date: 2022-10-25

Abstract

The disclosure provides a signal processing method, a signal processing device and signal processing equipment of a wavelength division multiplexing optical transmission system, and relates to the technical field of optical communication, in particular to the technical field of signal processing and chips. The specific implementation scheme is as follows: respectively acquiring at least two paths of initial signals; in the process of carrying out digital signal processing on initial signals, codes of the initial signals are mixed according to a set mixing and splitting algorithm and then split to form at least two paths of signals to be sent; and respectively outputting the optical signals to the modems with corresponding wavelengths for modulation so as to form at least two paths of optical signals. The scheme provides a new solution for digital signal processing of multiple paths of different waveband signals for a wavelength division multiplexing optical transmission system, and can balance the performance of the different waveband optical signals.

Description

Signal processing method, device and equipment of wavelength division multiplexing optical transmission system

Technical Field

The present disclosure relates to the field of optical communication technologies, and in particular, to the field of signal processing technologies and chip technologies.

Background

The C + L optical transmission system is a Wavelength Division Multiplexing optical transmission system in which an L-band similar to a C-band optical fiber loss and a spectral width is added to a Dense Wavelength Division Multiplexing (DWDM) technology based on a C-band to increase a single-fiber transmission total capacity by about one time.

Because the wavelength of the optical signal in the C waveband is shorter, and the wavelength of the optical signal in the L waveband is longer, when the optical signals in the C waveband and the optical signals in the L waveband are mixed and transmitted in one optical fiber, the transmission performance of the optical signals is different. This limits the overall quality and overall capacity of the optical fiber to transmit signals.

Disclosure of Invention

The present disclosure provides a signal processing method, apparatus, device and medium for a wavelength division multiplexing optical transmission system.

According to an aspect of the present disclosure, there is provided a transmission signal processing method of a wavelength division multiplexing optical transmission system, including:

respectively acquiring at least two paths of initial signals;

in the process of carrying out digital signal processing on initial signals, codes of the initial signals are mixed according to a set mixing and splitting algorithm and then split to form at least two paths of signals to be sent; each path of signals to be transmitted comprises a partial code of each initial signal;

outputting each signal to be transmitted to a modem with a corresponding wavelength for modulation to form at least two paths of optical signals; the optical signals are used for being combined and then transmitted to an opposite end in a wavelength division multiplexing mode in the optical fiber.

According to another aspect of the present disclosure, there is provided a received signal processing method of a wavelength division multiplexing optical transmission system, including:

respectively acquiring at least two paths of receiving signals received and demodulated from the optical fiber; wherein, the optical signals before each received signal demodulation are transmitted in the optical fiber by the light waves of at least two wave bands in a wavelength division multiplexing mode;

in the process of carrying out digital signal processing on received signals, the codes of all the received signals are mixed and split again according to a reverse algorithm of a set mixing and splitting algorithm of a sending end so as to form at least two paths of initial signals; wherein each received signal comprises a partial code of each of the original signals.

According to another aspect of the present disclosure, there is provided a digital signal processing apparatus including:

at least one processor; and

a memory communicatively coupled to the at least one processor; wherein, the first and the second end of the pipe are connected with each other,

the memory stores instructions executable by the at least one processor to enable the at least one processor to perform a transmission signal processing method of a wavelength division multiplexing optical transmission system or a reception signal processing method of the wavelength division multiplexing optical transmission system of any one of the embodiments of the present disclosure.

According to another aspect of the present disclosure, there is provided a coherent transceiver of a wavelength division multiplexing optical transmission system, including:

the digital signal processing chip is used for carrying out combined digital coding and decoding processing on at least two paths of signals;

and the at least two modems are used for respectively adopting light waves with corresponding wavelengths to modulate or demodulate at least two paths of signals.

According to another aspect of the present disclosure, there is provided an optical transmission device including:

at least one coherent transceiver of a wavelength division multiplexed optical transmission system provided by the present disclosure;

at least two wave band wave combiners for respectively receiving the optical signals of the corresponding wave bands output by the coherent transceivers and carrying out wave combination processing on the optical signals;

a band combiner for receiving the optical signals of at least two bands from each band combiner, and combining the optical signals of each band to form a wavelength division multiplexed combined optical signal; the composite optical signal is used for being transmitted by an input optical fiber;

a wavelength band splitter for receiving the output composite optical signal from the optical fiber and splitting the composite optical signal into optical signals of at least two wavelength bands;

and the at least two wave band wave splitters are used for respectively obtaining the optical signals of the corresponding wave bands from the wave band separators, performing wave splitting processing and inputting the optical signals to the coherent transceiver for demodulation and digital signal processing.

The scheme provides a solution for mixing and splitting signal codes to generate optical signals when digital signal processing is carried out on multiple paths of initial signals for the wavelength division multiplexing optical transmission system, can balance the performance of multiple paths of optical signals, and improves the overall quality and total capacity of optical fiber transmission signals.

It should be understood that the statements in this section do not necessarily identify key or critical features of the embodiments of the present disclosure, nor do they limit the scope of the present disclosure. Other features of the present disclosure will become apparent from the following description.

Drawings

The drawings are included to provide a better understanding of the present solution and are not to be construed as limiting the present disclosure. Wherein:

fig. 1A is a schematic diagram of a coherent transceiver of a wavelength division multiplexing optical transmission system provided in accordance with an embodiment of the present disclosure;

FIG. 1B is a schematic diagram of a client-side DSP provided in accordance with an embodiment of the present disclosure;

fig. 1C is a schematic diagram of a line-side dual-wavelength joint Tx DSP provided in accordance with an embodiment of the present disclosure;

FIG. 1D is a schematic diagram of a line-side dual-wavelength joint Rx DSP provided in accordance with an embodiment of the present disclosure;

1E-1F are schematic diagrams of a C-band modulator and an L-band modulator provided in accordance with an embodiment of the present disclosure;

FIGS. 1G-1H are schematic diagrams of a C-band demodulator and an L-band demodulator provided in accordance with embodiments of the present disclosure;

fig. 2A is a schematic diagram of an optical transmission device provided in accordance with an embodiment of the present disclosure;

FIG. 2B is a schematic illustration of a wavelength pairing relationship provided according to an embodiment of the disclosure;

fig. 3 is a schematic flowchart of a transmit signal processing method of a wavelength division multiplexing optical transmission system according to an embodiment of the present disclosure;

fig. 4A is a schematic flowchart of a transmit signal processing method of a wavelength division multiplexing optical transmission system according to an embodiment of the present disclosure;

fig. 4B is a schematic diagram of a process of performing digital signal processing on initial signal bit-domain coding by a sending end according to an embodiment of the present disclosure;

fig. 5A is a schematic flowchart of a transmit signal processing method of a wavelength division multiplexing optical transmission system according to an embodiment of the present disclosure;

fig. 5B is a schematic diagram of a process of performing digital signal processing on initial signal symbol domain coding by a sending end according to an embodiment of the present disclosure;

fig. 6 is a flowchart illustrating a received signal processing method of a wavelength division multiplexing optical transmission system according to an embodiment of the disclosure;

fig. 7A is a schematic flowchart of a received signal processing method of a wavelength division multiplexing optical transmission system according to an embodiment of the present disclosure;

fig. 7B is a schematic diagram of a process of a receiving end performing digital signal processing on bit-domain coding of a received signal according to an embodiment of the disclosure;

fig. 8A is a schematic flowchart of a received signal processing method of a wavelength division multiplexing optical transmission system according to an embodiment of the present disclosure;

fig. 8B is a schematic diagram of a process of a receiving end performing digital signal processing on received signal symbol domain coding according to an embodiment of the disclosure;

fig. 9 is a schematic structural diagram of a transmission signal processing apparatus of a wavelength division multiplexing optical transmission system according to an embodiment of the present disclosure;

fig. 10 is a schematic structural diagram of a received signal processing apparatus of a wavelength division multiplexing optical transmission system according to an embodiment of the present disclosure.

Detailed Description

Exemplary embodiments of the present disclosure are described below with reference to the accompanying drawings, in which various details of the embodiments of the disclosure are included to assist understanding, and which are to be considered as merely exemplary. Accordingly, those of ordinary skill in the art will recognize that various changes and modifications of the embodiments described herein can be made without departing from the scope and spirit of the present disclosure. Also, descriptions of well-known functions and constructions are omitted in the following description for clarity and conciseness.

In the related art, for a wavelength division multiplexing system, because the wavelengths of a plurality of optical signals of different wavelength bands are different, there may be some physical phenomena during hybrid transmission, typically, corresponding to a C + L wavelength division multiplexing system, because the wavelength of a C-band (C-band) optical signal is shorter, and the wavelength of an L-band (L-band) optical signal is longer, when the C-band and L-band optical signals are hybrid transmitted in one optical fiber, strong fiber Stimulated Raman Scattering (SRS) occurs, that is, the optical power of a short-wavelength (C-band) optical signal, and the optical power of a long-wavelength (L-band) optical signal are transferred.

For this physical phenomenon, the solution is: the outgoing incoming fiber power spectrum is pre-emphasized at the originating end and at each optical repeater site so that shorter (e.g., C-band) wavelengths enter the fiber at higher power and longer (e.g., L-band) wavelengths enter the fiber at lower power to offset the SRS effect, but this approach is labor and cost intensive.

In addition, fiber optic links in existing networks are often subject to unpredictable factors such as municipal construction, human inadvertent bending, etc., resulting in insertion loss and unpredictable degradation of the fiber optic links. Meanwhile, the SRS effect is also greatly reduced when the Optical fiber is degraded, so that the longer wavelength channel is not only reduced in power due to the link degradation, but also lost extra Optical power due to the reduction of power absorbed from the shorter wavelength channel, so that the link degradation is more degraded in the OSNR (Optical Signal Noise Ratio) of the longer wavelength channel at the receiving end (Rx), that is, rx OSNR, than the shorter wavelength channel, and the shorter wavelength channel is the same in power loss due to the channel degradation as the longer wavelength channel, but is degraded in the Rx OSNR due to the reduction of SRS transfer energy. Therefore, the stability and transmission distance of the conventional C + L system are limited by the worst performance channel (i.e., the longest L-band wave) in the failure state.

That is, there is an SRS scattering phenomenon during transmission due to a difference in wavelength band, and in addition, the transmission performance (i.e., optical power) of a signal in a long wavelength band is more rapidly decreased due to the deterioration of an optical fiber, and the decrease in optical power causes an error or ambiguity in the transmitted signal, i.e., the transmission quality is decreased, so that there are more erroneous codes during decoding, the error rate is high, i.e., the transmission performance is deteriorated, and the transmission performance in a short wavelength band is less affected.

Therefore, in the wavelength division multiplexing optical transmission system, the problem of unbalanced transmission performance and variation trend of optical signals with different wave bands exists. The above-mentioned difference in the transmission performance between the C-band and the L-band due to the deterioration of the optical fiber is a typical representative.

The disclosure provides a coherent transceiver of a wavelength division multiplexing optical transmission system, specifically a C + L dual-wavelength pairing coherent optical transceiver based on joint digital signal processing, and also provides an optical transmission device, specifically a C + L super-capacity coherent optical transmission device, for solving the problem of non-uniform performance of C-band and L-band wavelengths in a C + L DWDM (C + L dense wavelength division multiplexing) system under a fault state. It will be understood by those skilled in the art that the concept of joint processing of digital signals provided in the present disclosure is not limited to the wavelength division multiplexing optical transmission system of C-band and L-band, and can also be applied to the wavelength division multiplexing optical transmission scheme of other bands to equalize the optical signal performance quality.

Fig. 1A is a schematic diagram of a coherent transceiver of a wavelength division multiplexing optical transmission system provided according to an embodiment of the present disclosure, and fig. 1B is a schematic diagram of a client-side DSP provided according to an embodiment of the present disclosure; fig. 1C is a schematic diagram of a line-side dual-wavelength joint Tx DSP provided in accordance with an embodiment of the present disclosure; FIG. 1D is a schematic diagram of a line-side dual-wavelength joint Rx DSP provided in accordance with an embodiment of the present disclosure; 1E-1F are schematic diagrams of a C-band modulator and an L-band modulator provided in accordance with an embodiment of the present disclosure; fig. 1G-1H are schematic diagrams of a C-band demodulator and an L-band demodulator provided in accordance with an embodiment of the disclosure.

The coherent transceiver is an important component in optical transmission equipment, and is mainly used for performing coding and decoding of digital signal processing and modulation and demodulation of optical signals. The coherent transceiver of a wavelength division multiplexing optical transmission system provided by the embodiment of the present disclosure, as shown in fig. 1A, includes: the digital signal processing chip is used for carrying out combined digital coding and decoding processing on at least two paths of signals; and the at least two modems are used for respectively adopting light waves with corresponding wavelengths to modulate or demodulate at least two paths of signals. The light waves may be generated by a laser generator and may also be referred to as optical carriers.

The Digital Signal processing chip is a Digital Signal Processor (DSP). The digital signal processing chip may be specifically configured to perform encoding processing on the at least two initial signals and/or perform decoding processing on the at least two encoded received signals.

The number of the modems is at least two, corresponding to the number of the wavelengths to be processed, and taking processing of the C-band and the L-band as an example, the number of the modems includes two modems, and specifically may include at least one modem operating in the C-band and at least one modem operating in the L-band. A modem may include a modulator and a demodulator. The modulator and demodulator are two sets of hardware that are separately located. As shown in fig. 1E and 1F, the modulator may be configured to modulate the radio frequency signal encoded by the digital signal processing chip onto the optical wave with the corresponding wavelength by using the optical wave with the corresponding wavelength to form an optical signal; the demodulator, as shown in fig. 1G and 1H, may be configured to demodulate the optical signal received from the optical fiber with a light wave having a corresponding wavelength to form a radio frequency signal.

Optionally, the number of the digital signal processing chips is at least one, and the number of the modems is at least two, and the modems are used for modulating and demodulating the optical waves with the internal set wavelengths in at least two different wavebands.

Preferably, the number of the digital signal processing chips is one. The number of the modems is two, and the modems are respectively used for modulating and demodulating the light wave with a set wavelength in a C wave band and the light wave with a set wavelength in an L wave band.

It should be noted that, when the number of the digital signal processing chips provided by the present disclosure is one, the method for processing the transmission signal of the wavelength division multiplexing optical transmission system and the method for processing the reception signal of the wavelength division multiplexing optical transmission system according to the following embodiments of the present disclosure may be performed based on one digital signal processing chip, that is, the joint digital coding and decoding processing is performed on at least two paths of signals. When the number of the digital signal processing chips is multiple, the multiple digital signal processing chips may be matched with each other to respectively execute the sending signal processing method of the wavelength division multiplexing optical transmission system and the receiving signal processing method of the wavelength division multiplexing optical transmission system, and may also implement the joint digital encoding and decoding processing on at least two channels of signals, which is not limited by the present disclosure. For example, when the number of the DSP chips is 3, the first two DSP chips may separately process the codes of the two paths of signals that are independent of each other, the third DSP chip is responsible for processing the two paths of signals by mixing and splitting, and the first two DSP chips and the third DSP chip may be interconnected in hardware.

It should be noted that, the coherent transceiver described in the present disclosure may implement corresponding functions by using one data signal processing chip and two modems, which may effectively reduce the cost of the coherent transceiver.

Alternatively, the digital signal processing chip (DSP) may include both client-side and line-side functional groups, i.e., a client-side DSP and a line-side dual-wavelength joint DSP.

The coherent transceiver may include a transmitting end and a receiving end, for example, referring to fig. 1A, if the number of bands is two, which are a C band and an L band, respectively, the transmitting end may include: a client-side Rx DSP, a line-side dual-wavelength joint Tx DSP, a C-band modulator, and an L-band modulator. The receiving end includes: a C-band demodulator, an L-band demodulator, a line-side dual-wavelength joint Rx DSP, and a client-side Tx DSP.

Optionally, the number of initial signals input to the coherent transceiver is at least two, and the initial signals may also be referred to as client-side signals. For example, referring to fig. 1A, when the initial signals input into the coherent transceiver are two paths, the two paths of initial signals are first subjected to signal processing by the Rx DSP on the client side, and further subjected to joint digital coding processing by the dual-wavelength Tx DSP on the line side, so as to form radio frequency signals, and the radio frequency signals are divided into two parts, which are modulated by the C-band modulator and the L-band modulator, respectively, so as to generate C-band optical signals and L-band optical signals. After optical signals are transmitted in an optical fiber in a wavelength division multiplexing mode through light waves of a C wave band and an L wave band, a coherent transceiver can receive two paths of optical signals from the optical fiber, the two paths of optical signals are respectively input into a C wave band demodulator and an L wave band demodulator for demodulation, generated radio frequency signals are subjected to combined digital decoding processing through a line side dual-wavelength combined Rx DSP, and then are subjected to signal processing through a client side Tx DSP to generate two paths of initial signals and send the initial signals.

The client side DSP includes a client side Rx DSP and a client side Tx DSP. For example, referring to fig. 1B, the client Rx DSP or the client Tx DSP may perform signal processing including serdes (SERializer/DESerializer) access, PMA (physical medium adaptation layer), FEC Decoder (Forward Error Correction Decoder), and frame processing unit (framer). Specifically, the client-side signal is recovered and converted into the line-side signal through the Serdes access, the physical medium adaptation layer, the fec encoding and the frame processing unit.

Illustratively, referring to fig. 1C, the process of the line-side dual-wavelength joint Tx DSP performing the joint digital encoding process includes: joint SD-FEC Encoder, constellation Mapper, joint paper Precoding, pilot Symbol Insertion, tx FIR Filter, pulse shaping + Pre-emphasis + Tx sk + reset, and DAC. Specifically, a high-speed digital-to-analog converter outputs a high-speed RF signal (radio frequency signal) after line-side FEC loading, modulation matching, and spectrum shaping.

Illustratively, referring to fig. 1D, the process of performing the joint digital decoding process by the line-side dual-wavelength joint Rx DSP includes: ADC (Analog to digital converter), front-end Correction, CD Compensation, clock Recovery, adaptive MIMO Filter, carrier Frequency Offset Compensation, laser Phase Noise Compensation, cycle Slip Correction, joint pulse Decoding, constellation De-Mapper, and Joint SD-FEC Decoder.

With reference to fig. 1A, 1C and 1D, when the number of the digital signal processing chips is one, the chip has 8-channel DAC and ADC, and can have twice the processing capacity of the digital domain. Firstly, a sending end simultaneously receives client side signals with 2 times of quantity, after the client side signals are processed by a client side DSP (parallel discrete processing), the digital signals are simultaneously subjected to combined Soft decision forward error correction coding (SD-FEC), then are matched into symbols of corresponding modulation formats, namely bit domain signals are converted into symbol domain signals, then are aligned for error pair coding, and are subsequently divided into two parts, and the C wave band or L wave band photoelectric modulation is respectively carried out. At a receiving end, the optical signal of the C-band or L-band enters a DSP of the receiving end after being received by photoelectricity, the first part is divided into two parts to remove distortion (dispersion, polarization mode dispersion and the like) of the optical fiber in parallel and carry out carrier recovery, then carry out wrong pair decoding, carry out SD-FEC decoding after being converted into a bit domain signal through constellation matching, and finally output twice of a client side signal after passing through the DSP of the client side. The bit domain signal and the symbol domain signal are both digital signals processed in the DSP chip.

It should be noted that when processing signals in at least two bands, the DSP in the prior art also includes two parts, a client-side DSP and a line-side DSP, and the client-side DSP is mainly responsible for interfacing with ethernet devices, such as a switch serializer (Serdes). The digital signal processed by the client side DSP enters the line side DSP to carry out OTN (Optical Transport Network) encapsulation, independently executes bit domain coding, converts into a symbol domain by a constellation mapper, and carries out a symbol domain coding process. The symbol field code is modulated and then at least two optical signals are output. And the DSP provided by the disclosure inputs the line side DSP after processing the initial signal at the client side, and performs joint coding on bit domain coding and/or symbol domain, thereby realizing gain equalization of optical signals of different wave bands. The coherent transceiver of the present disclosure utilizes a digital signal processing chip to perform a joint digital encoding and decoding process on at least two signals, which will be described in detail in the following embodiments.

Illustratively, referring to fig. 1E and 1f, the c-band modulator and the L-band modulator each include: four drivers, C-band Laser or L-band Laser, four MZMs (plastic case breakers), pol Rot (components), and PBC (polarization beam combiner).

Illustratively, referring to fig. 1G and 1h, the c-band demodulator and the L-band demodulator respectively include: four TIA (Trans impedance amplifier), four BPDs (photodetector), X-Pol 90degree optical coupler, Y-Pol 90degree optical coupler, C-band Laser (C-band Laser) or L-band Laser (L-band Laser), and PBS (polarized beam splitter).

Of course, the coherent transceiver may also comprise other components for signal processing, for example at least two narrow linewidth tunable lasers for generating optical waves of different wavelengths, for example one for generating C-band wavelengths and one for generating L-band wavelengths.

The coherent transceiver disclosed by the disclosure has two sets of input/output optical signal interfaces of a C wave band and an L wave band, and can simultaneously send and receive a C-band signal and an L-band signal; the digital signal processing chip can be utilized to carry out combined digital coding and decoding processing on the signals of at least two wave bands, so that the balance of the wave band transmission performance in the aspect of digital coding is effectively realized; at least two modems can be used to modulate or demodulate at least two signals respectively by using light waves with corresponding wavelengths.

Fig. 2A is a schematic diagram of an optical transmission device provided according to an embodiment of the present disclosure, and fig. 2B is a schematic diagram of a wavelength pairing relationship provided according to an embodiment of the present disclosure.

The present disclosure also provides an optical transmission apparatus including:

at least one embodiment of the present disclosure provides a coherent transceiver of the wavelength division multiplexed optical transmission system;

the wave band synthesizer is used for receiving the optical signals of at least two wave bands from each wave band combiner, synthesizing the optical signals of each wave band and forming a wavelength division multiplexing synthesized optical signal; the synthetic optical signal is used for being input into an optical fiber for transmission;

a band splitter for receiving the output composite optical signal from the optical fiber and splitting the composite optical signal into optical signals of at least two bands;

and the at least two wave band wave splitters are used for respectively acquiring the optical signals of the corresponding wave bands from the wave band separators, performing wave splitting processing, and inputting the optical signals to the coherent transceiver for demodulation and digital signal processing.

Wherein, the wave band wave combiner synthesizes the light waves with the same wave band. The waveband synthesizer synthesizes optical signals of different wavebands. The wave band wave separator is used for separating the light waves of the same wave band. The waveband separator separates optical signals of different wavebands into optical signals of two wavebands.

Illustratively, referring to fig. 2A, the optical transmission device may include N joint DSP-based C + L dual-wavelength transceivers (i.e., the coherent transceiver described above in the present disclosure), each of which may output/receive optical signals of one C-band and one L-band simultaneously.

Specifically, after the C + L dual-wavelength transceivers 1 to N receive the initial signal, the optical signals generated after modulation and demodulation are respectively performed; the optical fiber is used for transmitting the combined wave to a C-band combined wave (namely a C-band wave combiner) for wave combination, and the combined wave is transmitted to a C-OA (C-band linear amplifier) for amplification through the optical fiber; meanwhile, the signals are transmitted to an L-band wave combiner (namely an L-band wave combiner) through optical fibers for wave combination, and the combined waves are transmitted to an L-OA (L-band linear amplifier) through the optical fibers for amplification; the optical signals amplified by the C-OA and the L-OA are transmitted to a C/L combined wave band (i.e. a wave band synthesizer), and the optical signals of each wave band are synthesized to form a synthesized optical signal of wavelength division multiplexing and transmitted from an outgoing optical fiber.

Specifically, the composite optical signal outputted from the incoming optical fiber is received, separated into optical signals of at least two bands by a C/L band splitter, respectively transmitted to a C-OA and an L-OA for reverse amplification, and then respectively transmitted to a C-band splitter (i.e., a C-band splitter) and an L-band splitter (i.e., an L-band splitter) for performing respective splitting processes, and then inputted to the C + L dual-wavelength transceiver 1 to the C + L dual-wavelength transceiver N for demodulation and digital signal processing.

The device comprises a plurality of coherent transceivers, a plurality of optical transceiver units and a plurality of optical transceiver units, wherein each coherent transceiver is used for processing an optical signal corresponding to a set wavelength in a C waveband and an optical signal corresponding to a set wavelength in an L waveband; the pairing relationship between the C-band wavelength and the L-band wavelength in each coherent transceiver satisfies the rule that the transmission quality of the C-band wavelength signal is increased gradually and the transmission quality of the L-band wavelength signal is decreased gradually.

Illustratively, taking a 50GHz C96+ L96 system as an example, the system is composed of 96C + L dual-wavelength transceivers, the wavelength of the 1 st transceiver is allocated to C1+ L96, the 2 nd transceiver is C2+ L95, and so on, and the wavelength of the 96 th transceiver is C96+ L1. Based on the rule that the transmission quality of the C-band wavelength signal increases progressively and the transmission quality of the L-band wavelength signal decreases progressively, referring to fig. 2B, the shortest C-band wavelength with a wavelength of 1529.16nm and the longest L-band wavelength with a wavelength of 1610.92nm are paired (pair 1), and input to a coherent transceiver; similarly, the C-band wavelength with the second shortest wavelength and the L-band wavelength with the second longest wavelength are paired and input to a coherent transceiver, and so on, the C-band wavelength with the wavelength of 1567.13nm and the L-band wavelength with the wavelength of 1570.83nm are paired (paired 96) and input to a coherent transceiver. That is, 96 coherent transceiver pairs are required to process the successfully paired 96C + L wavelength combinations.

In other words, the pairing relationship between the C-band wavelength and the L-band wavelength in each coherent transceiver satisfies the condition that the C-band wavelength number + the L-band wavelength number are equal to a constant value, for example, in a system of C-96+ L-96 (the wavelength number is 1-96 from short to long), the constant value is 97, and the specific pairing is: c1& L96, C2& L95 8230and C96& L1. The pairing rules aim to bring the average performance of each pair of wavelengths to unity.

It should be noted that, based on the fact that the SRS effect in the optical fiber is linear, and the performance linearly decreases from the shortest wavelength (C1) to the longest wavelength (L96) when the optical fiber is degraded (or interrupted), the optical fiber pair-wise inference principle of optimal & worst, suboptimal & inferior is adhered to during the pairing process, so that the pairing relationship between the C-band wavelength and the L-band wavelength in the coherent transceiver satisfies the rule that the transmission quality of the C-band wavelength signal increases progressively and the transmission quality of the L-band wavelength signal decreases progressively, and in this way, an implementable mode is provided for ensuring that the comprehensive performance of each pairing combination is close to unity.

The optical transmission device provided by the disclosure is characterized in that a plurality of coherent transceivers are arranged, each coherent transceiver simultaneously modulates, sends, receives and demodulates a wavelength channel of a C wave band and an L wave band, and the coherent transceivers are enabled to use a DSP chip to carry out combined digital Signal processing on signals of two wavelengths of two wave bands, so that symbol domain SNR (Signal to noise Ratio) and Bit rate BER (Bit Error Ratio) of double wavelengths can be consistent, and the transmission performance of optical signals of different wave bands under a fault state can be balanced.

Specifically, the algorithm for implementing the transmission performance equalization of the digital signal processing chip provided by the present disclosure will be described in detail in the following embodiments.

Fig. 3 is a schematic flowchart of a method for processing a transmitted signal of a wavelength division multiplexing optical transmission system according to an embodiment of the present disclosure, and the embodiment of the present disclosure is applicable to how a transmitting end of a coherent transceiver performs joint digital coding and decoding processing to generate two paths of signals to be transmitted for transmission. The method can be executed by a transmitting signal processing device of a wavelength division multiplexing optical transmission system, which can be realized by adopting a hardware and/or software mode, and can be configured in a digital signal processing device, such as a DSP chip of a coherent transceiver. Referring to fig. 3, the method specifically includes the following:

s101, at least two paths of initial signals are obtained respectively.

Wherein the initial signal is a signal which is acquired from upstream by the coherent transceiver and needs to be sent to the opposite terminal. Corresponding to different wave bands, a corresponding number of initial signals can be obtained, or the same initial signal can be split into multiple paths.

It should be noted that, the present disclosure refines that the number of wavelength bands of the wavelength division multiplexing optical transmission system may be two, that is, the C band and the L band, and improves the richness of the wavelength division multiplexing optical transmission system. In the embodiment of the present disclosure, the multiplexing of two bands, i.e., the C band and the L band, is taken as an example for explanation, but it can be understood by those skilled in the art that the technical solution provided in the present disclosure may also be applied when the system correspondingly multiplexes three or more bands.

And S102, in the process of carrying out digital signal processing on the initial signals, the codes of the initial signals are mixed according to a set mixing and splitting algorithm and then split to form at least two paths of signals to be transmitted.

The process of performing digital signal processing on the original signal, as described above, may be a series of processes such as client-side signal processing, bit-domain encoding processing of the line-side signal, symbol-domain encoding processing of the line-side signal, and so on. In this process, the initial signal encoding of one or more of the segments may be subjected to a hybrid splitting process.

The encoding of the initial signal refers to encoding after converting the initial signal into a bit domain or a coincidence domain. The encoding of the initial signal comprises bit-domain encoding and/or symbol-domain encoding of the initial signal. The hybrid splitting algorithm is an algorithm that can achieve hybrid splitting of codes of each initial signal and achieve that each path of signals to be transmitted includes partial codes of each initial signal. The signal to be transmitted is a signal subjected to digital signal processing by a client side Rx DSP and a line side dual-wavelength combined Tx DSP, and forms a radio frequency signal and is provided to a modulator to be modulated into an optical signal.

Optionally, the process of performing digital signal processing on the initial signal includes a process of performing signal processing through a client-side Rx DSP and through a line-side dual-wavelength joint Tx DSP.

Optionally, after obtaining at least two paths of initial signals, the coherent transceiver may first process the initial signals through corresponding client Rx DSPs, and convert the initial signals into bit-domain signals; and then, performing joint digital coding processing by using a line side dual-wavelength joint Tx DSP, specifically, performing bit coding first, converting a bit domain signal into a symbol domain signal by using a constellation mapper, and then performing symbol domain coding to generate at least two paths of radio frequency signals, namely, at least two paths of signals to be transmitted. At least one of the bit coding and the symbol field coding adopts a set hybrid splitting algorithm.

Specifically, the method for splitting the codes of the initial signals after mixing the codes according to a set mixing and splitting algorithm to form at least two signals to be transmitted includes:

mixing and splitting bit field codes of all initial signals according to a first set mixing and splitting algorithm, and forming at least two paths of signals to be sent based on the split first bit field codes;

and/or

And carrying out mixing and splitting on the symbol domain codes of the initial signals according to a second set mixing and splitting algorithm, and forming at least two paths of signals to be transmitted based on the split first symbol domain codes.

The first set hybrid splitting algorithm is an algorithm capable of performing hybrid splitting on bit field codes of the initial signals. The first bit-field coding is coding obtained by mixing and splitting bit-field codes of the original signals. The second set hybrid-split algorithm refers to an algorithm that can perform hybrid-split on the symbol-domain codes of the initial signals. The first symbol field coding is coding obtained by mixing and splitting the symbol field coding of each initial signal.

Illustratively, the first set hybrid-split algorithm may be a forward error correction coding algorithm and the second set hybrid-split algorithm may be an error pair coding algorithm.

Optionally, there are many possible implementation manners for the coherent transceiver to obtain at least two initial signals, convert the initial signals into bit domain signals by using the client Rx DSP, and perform joint coding by using the line dual-wavelength joint Tx DSP to generate at least two signals to be transmitted, for example, one possible implementation manner is: the bit field coding of each initial signal is mixed according to a first set mixing and splitting algorithm and then split, at least two split bit field signals are subjected to joint coding in the bit field, further, the at least two bit field signals are respectively converted into symbol field signals through a constellation mapper, then the symbol field coding is carried out to generate at least two radio frequency signals, namely, the at least two radio frequency signals are independently coded in the symbol field, and at least two signals to be sent are formed; another possible implementation is: respectively carrying out bit domain coding on at least two paths of initial signals, namely independently coding in a bit domain, then respectively converting the initial signals into symbol domain signals through a constellation mapper, then mixing and splitting the symbol domain signals according to the symbol domain coding and a second set mixed coding algorithm in the symbol domain, namely carrying out combined coding in the symbol domain, and forming at least two paths of signals to be sent based on the split first symbol domain coding; another possible implementation is: the bit domain coding of each initial signal is mixed and then split according to a first set mixing and splitting algorithm to generate at least two paths of bit domain signals, namely joint coding is carried out in the bit domain, the symbol domain coding of each initial signal is mixed and then split according to a second set mixing and splitting algorithm after being converted into symbol domain signals through a constellation mapper respectively, namely joint coding is carried out in the symbol domain, and at least two paths of signals to be sent are formed based on the split first symbol domain coding.

It should be noted that, in the prior art, at least two paths of initial signals are processed by at least two coherent transceivers, specifically, the initial signals are converted into bit domain signals through a client Rx DSP, converted into symbol domain signals through a constellation mapper, and signal processing is performed on the coincidence domain codes to form signals to be transmitted, and at least two coherent transceivers form at least two paths of signals to be transmitted. That is, in the prior art, two paths of optical signals with different wave bands are independent from each other in the process of digital signal processing. In the process of processing digital signals of each initial signal, the coherent transceiver mixes and splits the bit domain code and/or the symbol domain code of each initial signal according to the first set hybrid splitting algorithm and/or the second set hybrid splitting algorithm, namely performs joint digital coding processing, so that each path of signals to be transmitted can include part of codes of each initial signal, and the performance balance of the multipath optical transmission process can be realized conveniently in the follow-up process.

And S103, respectively outputting each signal to be transmitted to the modems with corresponding wavelengths for modulation so as to form at least two paths of optical signals.

The wave bands carrying the light waves of each path of signals to be transmitted are different, wherein each light signal is used for being transmitted to an opposite terminal in a wavelength division multiplexing mode in an optical fiber after being subjected to wave combination.

Optionally, each signal to be transmitted may be output to a modem with a corresponding wavelength, and the radio frequency signal is modulated on an optical wave with a corresponding wavelength to form at least two optical signals.

For example, if the wavelength band to which the optical wave of the signal to be transmitted belongs includes two wavelength bands, that is, a C band and an L band, the signal to be transmitted in the C band may be output to a modem with a corresponding wavelength, modulated by a modulator of the modem to generate an optical signal in the C band, output to a modem with a corresponding wavelength a signal to be transmitted in the L band, and modulated by a modulator of the modem to generate an optical signal in the L band, that is, at least two optical signals are formed.

According to the scheme of the embodiment of the disclosure, at least two paths of initial signals are respectively obtained, in the process of carrying out digital signal processing on the initial signals, the codes of the initial signals are mixed according to a set mixing and splitting algorithm and then split to form at least two paths of signals to be transmitted, and the signals to be transmitted are respectively output to a modem with a corresponding wavelength to be modulated to form at least two paths of optical signals. The scheme provides a new solution for digital signal processing of multiple paths of initial signals for a wavelength division multiplexing optical transmission system, and in consideration of the fact that different wave bands have different transmission performances and differences when transmitting signals, the signals to be transmitted generated by each path comprise partial codes of the initial signals in a mode of mixing and splitting signal codes, so that the balance of the transmission performances of the different wave bands can be effectively realized, namely the difference of the signal transmission performances caused by the different wave bands is balanced. Therefore, the long wavelength and the short wavelength share the performance allowance under the fault state, the consistency of the comprehensive performance is kept, and the integral stability and the transmission distance in the optical transmission process are greatly improved.

Fig. 4A is a schematic flow chart of a method for processing a transmission signal of a wavelength division multiplexing optical transmission system according to an embodiment of the present disclosure, and fig. 4B is a schematic flow chart of a process for performing digital signal processing on bit-domain codes of initial signals according to a transmission end provided by an embodiment of the present disclosure, in this embodiment, based on the above embodiment, a detailed explanation is further performed on that "bit-domain codes of each initial signal are mixed and then split according to a first set mixing and splitting algorithm, and at least two signals to be transmitted are formed based on the split first bit-domain codes", as shown in fig. 4A, the method includes:

s201, at least two paths of initial signals are respectively obtained.

S202, in the process of carrying out digital signal processing on the initial signals, the position sequence of the bit domain codes of the initial signals is adjusted to form a mixed bit domain code signal.

The mixed bit-field coded signal is a coded signal in which bit-field coding information of each original signal is mixed.

Optionally, the bit field codes of the initial signals may be combined first according to a preset position adjustment rule, then the position sequence of the codes is adjusted according to the preset adjustment rule, and the bit field codes after the position sequence is adjusted are used as mixed bit field coded signals, that is, mixed bit field coded signals are formed, for example, the bit field codes of two paths of initial signals are 16 bits, the first path is 1-16, the second path is 17-32, the 1 st, 17 th, 3 th, 19 th, 5 th, 21 th, 8230are interleaved together to form a new first path, and the 2 nd, 18 th, 4 th, 20 th, 6 th, 22 th, 8230are interleaved together to form a new second path.

Optionally, the position order of the bit field codes of the initial signals may also be adjusted according to a preset coding algorithm, specifically, the position order of the bit field codes of each initial signal is adjusted to form a mixed bit field coded signal, including: and carrying out forward error correction coding on the bit field codes of the initial signals to realize the adjustment of the coding position sequence and form a mixed bit field code signal.

Here, forward error correction coding (FEC) is a Soft decision coding algorithm (Soft decision).

For example, if the initial signal has two paths, which belong to the C band and the L band, respectively, the bit-field codes of the C band initial signal and the L band initial signal may be merged, and then forward error correction coding may be mixed, so as to adjust the coding position sequence, and form a mixed bit-field coded signal including the C band bit-field coded signal and the L band bit-field coded signal.

It should be noted that an implementation for generating a mixed bit-field coded signal by coding using forward error correction coding is provided, which can efficiently realize the adjustment of the coding position order and generate a mixed bit-field coded signal including the band bit-field coded signals.

Optionally, the method may further include performing hard-decision coding on the bit-field coding of the initial signal, then performing soft-decision coding, and finally performing joint coding to form a mixed bit-field coding signal, specifically, performing forward error correction coding on the bit-field coding of each initial signal to adjust the coding position sequence, so as to form a mixed bit-field coding signal, including: performing BCH coding and forward error correction coding on each initial signal respectively to obtain at least two paths of first independent coding signals of a bit domain; and combining the first independent coding signals, and carrying out forward error correction coding to realize the adjustment of the coding position sequence to form a mixed bit domain coding signal.

Among them, BCH encoding (Bose-Chaudhuri-Hocquenghem codes) is a Hard decision encoding algorithm (Hard decision). Forward error correction coding is a Soft decision coding algorithm (Soft decision). The first independently coded signal is a signal obtained by performing independent BCH coding and forward error correction coding.

Specifically, for each path of initial signals, BCH encoding is performed first, coding redundancy is increased, then forward error correction encoding is performed, and the position sequence of encoding is adjusted, so that at least two paths of first independent encoding signals of a bit field can be obtained. Furthermore, based on a preset combination rule, at least two paths of first independent coding signals are combined into one code, and forward error correction coding, namely joint coding, is performed on the code, so that the coding position sequence is adjusted, and thus a mixed bit field coding signal is formed.

It should be noted that, by using BCH coding to perform hard decision coding on the bit field coding of the initial signal, then using forward error correction coding to perform soft decision coding, then combining the two paths of coded signals, and finally using forward error correction coding to perform joint coding, an implementable manner for generating a mixed bit field coded signal is provided, which can effectively implement adjustment of the coding position sequence, so that each path of subsequently generated signals to be transmitted includes partial coding of each initial signal, thereby facilitating subsequent implementation of performance balance of optical signals of different bands.

S203, splitting the mixed bit field coding signal into at least two parts of codes, and forming at least two paths of signals to be transmitted based on the split first bit field codes.

The first bit field coding refers to bit field coding obtained by splitting and processing a mixed bit field coding signal by a sending end, and the number of the first bit field coding is at least two. Each first bit-field encoding contains information of the initial signal bit-field encoding of at least two bands.

Optionally, the mixed bit-field coded signal may be split into at least two parts of codes corresponding to the number of the initial signals according to a preset splitting rule and the number of the initial signals, for example, the mixed bit-field coded signal may be split into at least two parts of codes on average according to the number of bits of the mixed bit-field coded signal, and the split at least two parts of codes are further processed according to the preset rule to generate at least two split first bit-field codes, so as to further form at least two signals to be transmitted.

Optionally, splitting the mixed bit-domain coded signal into at least two parts of codes, and forming at least two signals to be transmitted based on the split first bit-domain code, including: splitting the mixed bit domain coded signal into at least two second independent coded signals; respectively carrying out Low Density Parity Check (LDPC) coding on each second independent coding signal to form at least two paths of split first bit field codes; and processing each split first bit field code through a symbol field to form at least two signals to be sent. The second independent encoding signal is a partial code obtained by splitting the mixed bit domain encoding signal. LDPC (Low Density Parity Check Code) coding refers to Low Density Parity Check coding.

For example, if the initial signal is two paths and belongs to the C-band and the L-band, respectively, the hybrid bit-field coded signal includes information of one set wavelength in the C-band and information of one set wavelength in the L-band, and after the hybrid bit-field coded signal is split into two paths of second independent coded signals, each path of the second independent coded signal includes information of the C-band wavelength and information of the L-band wavelength. After LDPC coding and symbol domain processing are performed, each channel of signals to be transmitted also includes information of the C-band wavelength and information of the L-band wavelength.

It should be noted that, by splitting the mixed bit-field coded signal, then performing LDPC coding and converting into a symbol field, and performing symbol field processing to generate two signals to be transmitted, a process of converting the mixed bit-field coded signal into at least two signals to be transmitted is refined, and information that each generated two signals to be transmitted includes signals of at least two bands can be effectively implemented.

Illustratively, referring to fig. 4B, two paths of original payload (i.e., bit-field coding of an original signal), referred to as coding 1 and coding 2, are respectively subjected to BCH coding, i.e., coding redundancy is increased, so as to generate coding 3 and coding 4, forward error correction coding is respectively performed on coding 3 and coding 4, i.e., coding 3 is subjected to internal independent mixing, so as to generate coding 5, coding 4 is subjected to internal independent mixing, so as to generate coding 6, then joint forward error correction coding is performed according to coding 5 and coding 6 (i.e., a first independent coding signal) after internal mixing, i.e., joint mixing is performed, so as to generate coding 7, where coding 7 includes information of coding 5 and coding 6, and then coding 7 is split into two parts, referred to as coding 8 and coding 9 (i.e., a second independent coding signal), coding 8 is subjected to LDPC coding, so as to generate coding 10, coding 9 is subjected to LDPC coding, so as to generate coding 11, and coding 10 and coding 11 are first split bit-field coding. Two paths of first bit field codes are processed in a symbol field, and two paths of signals to be sent can be generated.

It should be noted that, if the initial signal is two paths, which belong to the C band and the L band, respectively, and the error rates of the C band transmission signal and the L band transmission signal are 40% and 80% respectively without performing the joint coding, for the L band, since the error rate is higher than 70%, the quality of the signal transmission may be greatly reduced, and by the joint coding method disclosed in the present disclosure, the error rates of the C band transmission signal and the L band transmission signal may be an average value of two separate transmission error rates, that is, 60%, at this time, the transmission performance balance of the two bands may be ensured, and the quality of the two band signal transmission is improved.

And S204, respectively outputting each signal to be transmitted to the modem with the corresponding wavelength for modulation so as to form at least two paths of optical signals.

According to the scheme of the embodiment, in the process of carrying out digital signal processing on initial signals, the position sequence of the bit field codes of each initial signal is adjusted to form a mixed bit field code signal, the mixed bit field code signal is split into at least two parts of codes, at least two paths of signals to be sent are formed based on the split first bit field code, and finally at least two paths of optical signals are generated by using a modem. An implementable mode that the bit field codes of the initial signals are mixed and then split to form signals to be sent is provided, the performance average of the bit field can be realized, and the subsequent total error rate is equal to the average value of the original total error rates of all wave bands.

Fig. 5A is a schematic flow chart of a method for processing a transmission signal of a wavelength division multiplexing optical transmission system according to an embodiment of the present disclosure, and fig. 5B is a schematic flow chart of a process for performing digital signal processing on symbol domain codes of initial signals according to a transmission end provided by an embodiment of the present disclosure, where in this embodiment, a detailed explanation is further performed on that "symbol domain codes of each initial signal are mixed and then split according to a second set mixing and splitting algorithm, and at least two signals to be transmitted are formed based on a split first symbol domain code", and as shown in fig. 5A, the method includes:

s301, at least two paths of initial signals are respectively obtained.

S302, the in-phase component and the orthogonal component in two polarization states in the symbol domain code of each initial signal are respectively exchanged and recombined to form at least two split first symbol domain codes, and at least two signals to be sent are formed based on the at least two split first symbol domain codes.

After each path of bit domain signal is converted into a symbol domain signal, signals of two polarization states are formed; the signal for each polarization state comprises two independent components, an in-phase component (I component for short) and a quadrature component (Q component for short). For example, the symbol domain signal corresponding to the C band can be expressed as C by the formula _XI +j·C _XQ The subscript represents the X polarization state, the subscript I represents the in-phase component, and the subscript Q represents the quadrature component. Similarly, the C-band Y-polarization sign-domain signal is expressed as C _YI +j·C _YQ (ii) a The X polarization state symbol domain signal of the L wave band is expressed as L _XI +j·L _XQ (ii) a The Y polarization state symbol domain signal of the L wave band is expressed as L _YI +j·L _YQ 。

The exchange recombination refers to coding recombination realized by exchanging I components and Q components coded by different polarization states. The first symbol domain coding refers to coding containing at least two paths of initial signal symbol domain coding information.

Optionally, if the number of the initial signals is two, correspondingly, the in-phase component and the quadrature component in the symbol domain code of each initial signal in two polarization states are respectively exchanged and recombined to form at least two split first symbol domain codes, including: and respectively processing the codes of the in-phase component and the orthogonal component in two polarization states in the symbol domain codes of the two paths of initial signals by adopting a wrong pair coding algorithm according to the two polarization states to form at least two paths of split first symbol domain codes.

The code cross Coding (PairWise Coding) algorithm is an algorithm which can exchange the orthogonal component of one polarization state and the in-phase component of the other polarization state in the symbol domain codes of two paths of initial signals.

Optionally, one path of Q component and one path of I component of signals with different polarization states in the symbol domain codes of the two paths of initial signals are exchanged based on a wrong pair coding algorithm, and the other path of Q component and the other path of I component are left unchanged, so as to form at least two paths of split first symbol domain codes, wherein each first symbol domain code contains information of initial signals with different wave bands.

For example, referring to fig. 5B, if the initial signal has two paths, which belong to the C band and the L band, respectively, the symbol domain of the initial signal is encoded, and the process of processing by using the wrong pair encoding algorithm is as follows:

1. the sign domain coding (dual-polarized electric field signal) of the initial signals of the C-band and L-band is expressed as:

Ori _C，X ＝C _XI +j·C _XQ

Ori _C，Y ＝C _YI +j·C _YQ

Ori _L，X ＝L _XI +j·L _XQ

Ori _L，Y ＝L _YI +j·L _YQ

wherein Ori _C，X 、Ori _C，Y 、Ori _L，X And Ori _L，Y Respectively a C-band X-polarization state electric field signal, a C-band Y-polarization state electric field signal, an L-band X-polarization state electric field signal and an L-band Y-polarization state electric field signal.

2. After a constant phase θ =45 ° Rotation (Angle Rotation), the signals of the respective X and Y polarization states of the C-band and L-band are expressed as:

Rot _C，X ＝Ori _C，X ·e ^jθ

Rot _C，Y ＝Ori _C，Y ·e ^jθ

Rot _L，X ＝Ori _L，X ·e ^jθ

Rot _L，Y ＝Ori _L，Y ·e ^jθ

3. carrying out I/Q Interleaving processing (I/Q Interleaving) on the C-band signal and the L-band signal, namely, encoding Q components and I components of signals with different polarization states in the symbol domain encoding of the two paths of initial signals, and processing by adopting an error pair encoding algorithm:

wherein the content of the first and second substances,

the representation is taken in the real part,

the representation takes the imaginary part. Need to make sure thatNote that Tx output after processing by the wrong pair coding algorithm _C，X 、Tx _C，Y 、Tx _L，X And Tx _L，Y Are first symbol domain codes, each containing partial information of the C-band and L-band signals. As shown in fig. 5B, the mismatching encoding algorithm specifically exchanges the C-band X polarization Q component encoding with the L-band X polarization I component; the code of the I component of the C wave band X polarization state is unchanged from the Q component of the L wave band X polarization state; the code of the Q component of the Y polarization state of the C wave band is exchanged with the I component of the Y polarization state of the L wave band; the I component code of the C-band Y polarization state is unchanged from the Q component of the L-band Y polarization state.

It should be noted that, by adopting the wrong pair encoding algorithm to perform exchange and recombination on the codes of the Q component and the I component in different polarization states in the symbol domain code, an implementable manner for processing the symbol domain code of the initial signal is provided, so that the split first symbol domain code can contain partial information of the initial signal of each band, and the performance of the symbol domain at the receiving end is kept equal after the wavelengths of different bands are decoded, thereby realizing the balance of transmission performance.

Optionally, before the in-phase component and the orthogonal component in two polarization states in the symbol domain code of each initial signal are respectively exchanged and recombined, the method further includes: and acquiring the bit domain code of each initial signal, and respectively converting the bit domain code into the symbol domain code of the initial signal.

Optionally, the coherent transceiver may convert each of the initial signals into a bit-domain signal via the client-side Rx DSP, i.e. obtain the bit-domain encoding of each of the initial signals,

optionally, a constellation mapper may be directly adopted to convert bit domain codes of each initial signal into symbol domain codes respectively; or the bit field codes of the initial signals can be mixed and split according to a first set mixing and splitting algorithm, and then the split bit field codes are respectively converted into symbol field codes by adopting a constellation mapper, namely the symbol field codes of the initial signals are respectively converted into the symbol field codes of the initial signals.

It should be noted that, by obtaining the bit-domain code of each initial signal and converting the bit-domain code into the symbol-domain code, the operation of performing the swapping and recombining of the codes of different phases of the symbol-domain code according to the present embodiment can be facilitated.

S303, outputting each signal to be transmitted to a modem with a corresponding wavelength for modulation, so as to form at least two optical signals.

In the scheme of the embodiment of the disclosure, the in-phase component and the quadrature component in two polarization states in the symbol domain code of each initial signal are respectively exchanged and recombined to form at least two split first symbol domain codes, and at least two signals to be transmitted are formed based on the at least two split first symbol domain codes, so as to form at least two optical signals. The codes of the in-phase component and the orthogonal component in two polarization states in the symbol domain code are exchanged, recombined and split, so that an implementable mode of carrying out mixed splitting on the symbol domain codes of the initial signals of different wave bands is provided, and the balance of the signal-to-noise ratio performance in the symbol domain can be realized.

Fig. 6 is a schematic flowchart of a received signal processing method of a wavelength division multiplexing optical transmission system according to an embodiment of the present disclosure, which is applicable to how a receiving end of a coherent transceiver in the wavelength division multiplexing optical transmission system performs received signal processing. The method can be executed by a receiving signal processing device of a wavelength division multiplexing optical transmission system, can be realized by adopting a hardware and/or software mode, and can be configured in a digital signal processing device. Referring to fig. 6, the method specifically includes the following:

s401, at least two paths of receiving signals received and demodulated from the optical fiber are respectively obtained.

The optical signals before demodulation of each received signal are transmitted in the optical fiber through light waves of at least two wave bands in a wavelength division multiplexing mode. The received signal is a radio frequency signal generated by demodulating a light signal received from the optical fiber.

The optical signal received from the optical fiber is an optical signal that is generated by performing the transmission signal processing method of the wavelength division multiplexing optical transmission system according to the present disclosure, and is transmitted in a wavelength division multiplexing manner in the optical fiber after combining the at least two optical signals.

Optionally, the coherent transceiver may receive at least two optical signals from the optical fiber, demodulate an optical wave with a set wavelength in each wavelength band, and generate at least two received signals, that is, obtain at least two received signals received and demodulated from the optical fiber.

Optionally, the number of the bands is two, which are a C band and an L band. Accordingly, the coherent transceiver can acquire two paths of optical signals received from the optical fiber, and demodulate an optical wave with a set wavelength in the C-band and an optical wave with a set wavelength in the L-band by using the demodulator to generate at least two paths of received signals.

It should be noted that by giving the number of bands two and thinning to the C-band and L-band, one possible form of the wavelength division multiplexing optical transmission system is given.

S402, in the process of carrying out digital signal processing on the received signals, the codes of all the received signals are mixed and split again according to the reverse algorithm of the set mixing and splitting algorithm of the sending end to form at least two paths of initial signals.

Wherein each received signal comprises a partial code of the respective original signal. The encoding of the received signal refers to encoding after converting the received signal into a bit domain and a coincidence domain. The encoding of the received signal comprises bit-domain encoding and/or symbol-domain encoding of the received signal. The inverse algorithm of the hybrid splitting algorithm is an algorithm for decoding a signal encoded by the hybrid splitting algorithm to obtain an initial signal. The initial signal is an optical signal generated by performing digital signal processing on a received signal.

Optionally, the process of performing digital signal processing on the received signal includes performing digital signal processing through the line-side dual-wavelength joint Rx DSP and the client-side Tx DSP.

Optionally, the method for splitting the codes of the received signals after mixing the codes according to the inverse algorithm of the set mixing and splitting algorithm of the sending end to form at least two paths of initial signals includes: the bit field codes of all received signals are mixed and split according to a first reverse algorithm of a first set mixing and splitting algorithm of a sending end, and at least two paths of initial signals are formed on the basis of split second bit field codes; and/or the symbol domain codes of all the received signals are mixed and then split according to a second inverse algorithm of a second set mixing and splitting algorithm of the sending end, and at least two paths of initial signals are formed based on the split second symbol domain codes.

Wherein the first inverse algorithm is an algorithm for decoding a signal encoded by the first set hybrid-split algorithm. The second inverse algorithm is an algorithm for decoding the signal encoded by the second set hybrid-split algorithm.

Illustratively, if the first set hybrid splitting algorithm is a forward error correction coding algorithm, the first inverse algorithm is a corresponding forward error correction decoding algorithm. And if the second set hybrid splitting algorithm is an error-pair encoding algorithm, the second reverse algorithm is a corresponding error-pair decoding algorithm.

It should be noted that, in the process of performing digital signal processing on each received signal, the coherent transceiver according to the present disclosure mixes and then splits the bit domain code and/or the symbol domain code of each received signal according to the first inverse algorithm and/or the second inverse algorithm corresponding to the sending end, that is, performs joint digital decoding processing, and can decode the received signal including part of the codes of each initial signal, thereby implementing performance equalization in the process of multipath optical transmission.

According to the scheme of the embodiment, at least two paths of receiving signals received and demodulated from the optical fiber are respectively obtained, and in the process of carrying out digital signal processing on the receiving signals, codes of the receiving signals are mixed and then split according to a reverse algorithm of a set mixing and splitting algorithm of a sending end, so that at least two paths of initial signals are formed. The scheme provides a new solution for processing digital signals of multiple paths of received signals for a wavelength division multiplexing optical transmission system, and considering that the transmission performances of different wave bands are different when the signals are transmitted, the difference exists, the received signals containing partial codes of each initial signal are decoded by a mode of reversely mixing and splitting codes of the received signals, and the balance of the transmission performances of different wave bands can be effectively realized, namely, the difference of the signal transmission performances caused by different wave bands is balanced. Therefore, the long wavelength and the short wavelength share the performance allowance under the fault state, the consistency of the comprehensive performance is kept, and the integral stability and the transmission distance in the optical transmission process are greatly improved.

Fig. 7A is a schematic flow chart of a received signal processing method of a wavelength division multiplexing optical transmission system according to an embodiment of the present disclosure, and fig. 7B is a schematic flow chart of a process of performing digital signal processing on bit-domain codes of received signals by a receiving end according to an embodiment of the present disclosure, in this embodiment, based on the above embodiment, a detailed explanation is further performed on "encoding bit-domains of received signals, mixing and splitting the bit-domains according to a first inverse algorithm of a first set mixing and splitting algorithm at a transmitting end, and forming at least two initial signals based on a split second bit-domain code", as shown in fig. 7A, the method includes:

s501, at least two paths of receiving signals received and demodulated from the optical fiber are respectively obtained.

S502, in the process of carrying out digital signal processing on the received signals, the position sequence of the bit field codes of all the received signals is adjusted according to the reverse algorithm of the position sequence adjustment algorithm of the transmitting end so as to form a mixed bit field decoding signal.

The mixed bit-domain decoded signal is a decoded signal in which bit-domain decoding information of each original signal is mixed.

Optionally, the adjusting the position order of the bit field codes of each received signal according to the decoding algorithm corresponding to the encoding algorithm of the sending end, specifically, the adjusting the position order of the bit field codes of each received signal according to the inverse algorithm of the position order adjusting algorithm of the sending end, so as to form the mixed bit field decoded signal, includes: and carrying out forward error correction decoding on the bit field codes of the received signals to realize the adjustment of the code position sequence and form a mixed bit field decoding signal.

It should be noted that, by decoding with the decoding algorithm of the forward error correction coding algorithm corresponding to the transmitting end, an implementable manner for generating the mixed bit domain decoded signal is provided, and the adjustment of the coding position sequence can be effectively realized.

Optionally, the performing forward error correction decoding on the bit field codes of the received signals to realize adjustment of the coding position sequence, and forming a mixed bit field decoded signal includes: respectively performing LDPC decoding on the bit field codes of all the received signals to form at least two paths of third independent decoding signals; and combining the third independent decoding signals, and performing forward error correction decoding to realize the adjustment of the coding position sequence to form a mixed bit domain decoding signal.

Among them, LDPC (Low Density Parity Check Code) decoding is an inverse algorithm of LDPC encoding.

It should be noted that, by performing LDPC decoding, dividing the bit-field encoding of each received signal into two decoded signals, and then performing forward error correction decoding on the combined decoded signals, an implementable manner of generating a mixed bit-field decoded signal is provided, which can effectively implement adjustment of the encoding position sequence, and mix the bit-field decoding of the received signals, thereby facilitating subsequent decoding of two initial signals corresponding to the received signals.

S503, splitting the mixed bit domain decoding signal into at least two parts of codes, and forming at least two paths of initial signals based on the split second bit domain codes.

The second bit field coding refers to bit field coding obtained by a receiving end splitting and processing the mixed bit field decoding signal, and the number of the second bit field coding is at least two.

Optionally, splitting the mixed bit domain decoded signal into at least two parts of codes, and forming at least two paths of initial signals based on the split second bit domain codes, including: splitting the mixed bit domain decoding signal into at least two paths of fourth independent decoding signals; and respectively carrying out forward error correction decoding and BDH decoding on each fourth independent decoding signal to form at least two paths of bit domain codes, and respectively forming at least two paths of initial signals based on each bit domain code.

It should be noted that, the process of converting the mixed bit domain coded signal into at least two initial signals is refined by splitting the mixed bit domain coded signal, and then performing forward error correction decoding and BDH decoding, respectively, based on the generated bit domain codes, so as to realize the process of converting the optical signal containing at least two wave bands into at least two initial signals.

For example, referring to fig. 7B, two paths of received signals, referred to as code 1 and code 2, are respectively LDPC-decoded to generate code 3 and code 4, that is, two paths of third independent decoded signals, and then each of the third independent decoded signals is combined and joint forward error correction decoding is performed by using a forward error correction decoding algorithm, that is, joint mixing is performed to generate code 7, that is, a mixed bit domain decoded signal, and then code 7 is split into two parts, referred to as code 8 and code 9 (that is, a fourth independent decoded signal), each of the fourth independent decoded signals is respectively forward error correction decoded and BDH decoded, code 8 is forward error correction decoded and BDH decoded to generate code 10, code 9 is forward error correction decoded and BDH decoded to generate code 11, and code 10 and code 11 are two paths of bit domain codes. And converting the two paths of bit domain codes into optical signals, namely forming two paths of initial signals.

According to the scheme of the embodiment, in the process of carrying out digital signal processing on the received signals, the position sequence of the bit field codes of each received signal is adjusted according to the reverse algorithm of the position sequence adjustment algorithm of the sending end to form a mixed bit field decoding signal, the mixed bit field decoding signal is split into at least two parts of codes, and at least two paths of initial signals are formed based on the split second bit field codes. An implementable mode for decoding the received signal into the initial signal is provided, and the performance average of a bit field can be realized, so that the subsequent total error rate is equal to the average value of the original total error rates of all wave bands.

Fig. 8A is a schematic flow chart of a received signal processing method of a wavelength division multiplexing optical transmission system according to an embodiment of the present disclosure, and fig. 8B is a schematic flow chart of a process of performing digital signal processing on a received signal symbol domain code by a receiving end according to an embodiment of the present disclosure, in this embodiment, based on the above embodiment, a detailed explanation is further performed on "encoding symbol domains of received signals, mixing and splitting the encoded symbol domains according to a second inverse algorithm of a second set mixing and splitting algorithm at a transmitting end, and forming at least two initial signals based on the split second symbol domain code", as shown in fig. 8A, the method includes:

s601, at least two paths of receiving signals received and demodulated from the optical fiber are respectively obtained.

S602, in the process of processing the digital signals of the received signals, the in-phase component and the orthogonal component in two polarization states in the symbol domain code of each received signal are respectively exchanged, restored and recombined to form at least two paths of split second symbol domain codes, and at least two paths of initial signals are formed based on each split second symbol domain code.

The exchange reduction and recombination refers to reverse exchange reduction operation of the codes exchanged and recombined by the sending end. The second symbol domain coding refers to at least two paths of symbol domain coding formed after exchange reduction recombination is carried out. The second symbol field encoding is the same as the first symbol field encoding.

Optionally, if the number of the received signals is two, then correspondingly, the in-phase component and the quadrature component in two polarization states in the symbol domain code of each received signal are respectively exchanged, restored and recombined to form at least two split second symbol domain codes, including: and respectively carrying out exchange reduction recombination on codes of in-phase components and orthogonal components in two polarization states in the symbol domain codes of the two paths of received signals by adopting a wrong pair coding algorithm according to the two polarization states so as to form at least two paths of split second symbol domain codes.

For example, referring to fig. 8B, if the received signal has two paths, which belong to the C band and the L band, respectively, the symbol domain of the received signal is encoded, and the process of processing by using the wrong pair encoding algorithm is as follows:

1. the symbol domain codes of the received signals are amplified separately.

Resc _C，X ＝Rx _C，X ·sqrt(SNR _C，X )

Resc _C，Y ＝Rx _C，Y ·sqrt(SNR _C，Y )

Resc _L，X ＝Rx _L，X ·sqrt(SNR _L，X )

Resc _L，Y ＝Rx _L，Y ·sqrt(SNR _L，Y )

Wherein the SNR _C，X ，SNR _C，Y ，SNR _L，X ，SNR _L，Y The SNR values are respectively estimated according to signals after C wave band X polarization, C wave band Y polarization, L wave band X polarization and L wave band Y polarization equalization.

2. Performing I/Q de-Interleaving processing (I/Q de-Interleaving) of a C wave band and an L wave band:

3. and carrying out hard decision on the I/Q deinterleaved signal based on Maximum Likelihood theorem (MLD). And (3) rotating the original symbol table by theta =45 degrees to obtain a new symbol table, and then amplifying the I and Q branches according to the C-band SNR and the L-band SNR respectively to obtain a final decision reference symbol table. And finally, calculating the Euclidean distance between each I/Q de-interleaved signal and a final decision reference symbol table, and judging the signal as a corresponding original symbol according to the minimum Euclidean distance. The calculation formula is referred to as follows:

(a) Original symbol table

Ori _sym = { sym1, sym 2.. SymN }, in the case of QPSK modulation，N＝4，sym1＝1+j，sym2＝1-j，sym3＝-1+j，sym4＝-1-j。

(b) The symbol table after rotation is:

Rot _sym ＝{Rot _sym1 ，Rot _sym2 ，...Rot _symN }

＝{sym1·e ^jθ ，sym2·e ^jθ ，...symN·e ^jθ }

(c) The final decision reference symbol table is (one final decision reference symbol table is shared by each polarization state of the C-band and the L-band), taking the X-polarization state as an example:

Dec _C，X1 ＝argmin _i |DeInt _C，X1 -DecRef _sym，Xi |(for i＝1，2，...，N)

taking QPSK as an example, if the MLD detection return value is 2 as described above, the symbol is finally determined to be 1-j in the original symbol table.

It should be noted that, by adopting the wrong pair encoding algorithm to respectively exchange, restore and recombine the in-phase component and the orthogonal component in the two polarization states in the symbol domain encoding, an implementable manner for processing the symbol domain encoding of the received signal is provided, decoding corresponding to the symbol domain encoding is realized, the performance of the optical signals of different wave bands in the symbol domain of the receiving end is kept equal, and thus the balance of the transmission performance is realized.

Optionally, at least two paths of initial signals are formed based on the split second symbol domain coding, including: and converting each second symbol domain code into a bit domain code, and performing bit domain decoding processing on the bit domain code to form at least two paths of initial signals.

It should be noted that the process of generating the initial signal is refined by converting the split symbol domain coding into bit domain coding and performing bit domain decoding processing.

In the scheme of the embodiment of the disclosure, in the process of processing the digital signals of the received signals, the in-phase component and the orthogonal component in the symbol domain code of each received signal in two polarization states are respectively exchanged, restored and recombined to form at least two split second symbol domain codes, and at least two initial signals are formed based on each split second symbol domain code. The in-phase component and the orthogonal component in two polarization states in the symbol domain coding are respectively exchanged, restored and recombined, so that an implementable mode that a received signal is obtained and then converted into an original initial signal is provided.

Fig. 9 is a schematic structural diagram of a transmit signal processing apparatus of a wavelength division multiplexing optical transmission system according to an embodiment of the present disclosure, which is applicable to a case how a digital signal processing chip of a coherent transceiver generates a transmit signal. The apparatus can be implemented in software and/or hardware. The method can be particularly integrated in a digital signal processing device with a transmission signal processing function of a wavelength division multiplexing optical transmission system. As shown in fig. 9, the transmission signal processing apparatus 900 of the wavelength division multiplexing optical transmission system includes:

an initial signal obtaining module 901, configured to obtain at least two paths of initial signals respectively;

a transmission signal generating module 902, configured to mix and split codes of each initial signal according to a set mixing and splitting algorithm to form at least two signals to be transmitted in a process of performing digital signal processing on the initial signals; each path of signals to be transmitted comprises a partial code of each initial signal;

an optical signal generating module 903, configured to output each signal to be transmitted to a modem with a corresponding wavelength for modulation, so as to form at least two optical signals; the wave bands carrying the optical waves of each path of signals to be transmitted are different, and each optical signal is used for being transmitted to an opposite terminal in a wavelength division multiplexing mode in an optical fiber after being combined.

The scheme provides a new solution for digital signal processing of multiple paths of initial signals for a wavelength division multiplexing optical transmission system, and in consideration of the fact that different wave bands have different transmission performances and differences when transmitting signals, the signals to be transmitted generated by each path comprise partial codes of the initial signals in a mode of mixing and splitting signal codes, so that the balance of the transmission performances of the different wave bands can be effectively realized, namely the difference of the signal transmission performances caused by the different wave bands is balanced. Therefore, the long wavelength and the short wavelength share the performance allowance under the fault state, the consistency of the comprehensive performance is kept, and the integral stability and the transmission distance in the optical transmission process are greatly improved.

Further, the transmission signal generating module 902 may include:

a first transmission signal generating unit, configured to mix and split bit-domain codes of the initial signals according to a first set mixing and splitting algorithm, and form at least two signals to be transmitted based on the split first bit-domain codes; and/or

And the second sending signal generating unit is used for mixing and splitting the symbol domain codes of the initial signals according to a second set mixing and splitting algorithm, and forming at least two paths of signals to be sent based on the split first symbol domain codes.

Further, the first transmission signal generation unit may include:

a coded signal generating subunit, configured to adjust the bit-field coding position sequence of each of the initial signals to form a mixed bit-field coded signal;

and the sending signal generating subunit is used for splitting the mixed bit domain coded signal into at least two parts of codes and forming at least two paths of signals to be sent based on the split first bit domain code.

Further, the encoded signal generating subunit is specifically configured to:

and carrying out forward error correction coding on the bit field codes of the initial signals to realize the adjustment of the coding position sequence and form a mixed bit field code signal.

Further, the encoded signal generating subunit is specifically configured to:

performing BCH coding and forward error correction coding on each initial signal respectively to obtain at least two paths of first independent coding signals of a bit field;

and combining the first independent coding signals, and carrying out forward error correction coding to realize the adjustment of the coding position sequence to form a mixed bit domain coding signal.

Further, the transmission signal generating subunit is specifically configured to:

splitting the mixed bit domain coded signal into at least two second independent coded signals;

respectively carrying out low-density parity check (LDPC) coding on each second independent coding signal to form at least two paths of split first bit field codes;

and processing each split first bit field code through a symbol field to form at least two paths of signals to be transmitted.

Further, the second transmission signal generating unit is specifically configured to:

and respectively carrying out exchange recombination on in-phase components and orthogonal components in two polarization states in the symbol domain codes of each initial signal to form at least two paths of split first symbol domain codes, and forming at least two paths of signals to be transmitted based on the at least two paths of split first symbol domain codes.

Further, the number of the initial signals is two; the second transmission signal generation unit is specifically configured to:

and respectively processing the codes of the in-phase component and the orthogonal component in two polarization states in the symbol domain codes of the two paths of initial signals by adopting a wrong pair coding algorithm according to the two polarization states to form at least two paths of split first symbol domain codes.

Further, the transmission signal generating module 902 is further configured to:

before the in-phase component and the orthogonal component in two polarization states in the symbol domain code of each initial signal are respectively exchanged and recombined, the bit domain code of each initial signal is obtained and is respectively converted into the symbol domain code of the initial signal.

Furthermore, the number of the wave bands is two, namely a C wave band and an L wave band.

Fig. 10 is a schematic structural diagram of a received signal processing apparatus of a wavelength division multiplexing optical transmission system according to an embodiment of the present disclosure, which is applicable to a case how a digital signal processing chip of a coherent transceiver decodes received signal information to generate an initial signal. The apparatus can be implemented in software and/or hardware. The method can be particularly integrated in a digital signal processing device with a received signal processing function of a wavelength division multiplexing optical transmission system. As shown in fig. 10, the received signal processing apparatus 1000 of the wavelength division multiplexing optical transmission system includes:

a received signal acquisition module 1001 configured to respectively acquire at least two paths of received signals received and demodulated from an optical fiber; wherein, the optical signals before each received signal demodulation are transmitted in the optical fiber by the light waves of at least two wave bands in a wavelength division multiplexing mode;

an initial signal generating module 1002, configured to mix and split codes of each received signal according to a reverse algorithm of a set mixing and splitting algorithm of a sending end in a process of performing digital signal processing on the received signal, so as to form at least two paths of initial signals; wherein each received signal comprises a partial code of each of the original signals.

The scheme provides a new solution for processing digital signals of multiple paths of received signals for a wavelength division multiplexing optical transmission system, and considering that the transmission performances of different wave bands are different when the signals are transmitted, the difference exists, the received signals containing partial codes of each initial signal are decoded by a mode of reversely mixing and splitting codes of the received signals, and the balance of the transmission performances of different wave bands can be effectively realized, namely, the difference of the signal transmission performances caused by different wave bands is balanced. Therefore, the long wavelength and the short wavelength share the performance allowance under the fault state, the consistency of the comprehensive performance is kept, and the integral stability and the transmission distance in the optical transmission process are greatly improved.

Further, the initial signal generating module 1002 may include:

a first initial signal generating unit, configured to mix and split bit-domain codes of each received signal according to a first inverse algorithm of a first set mixing and splitting algorithm at a sending end, and form at least two paths of initial signals based on split second bit-domain codes; and/or

And the second initial signal generating unit is used for mixing and splitting the symbol domain codes of the received signals according to a second inverse algorithm of a second set mixing and splitting algorithm of the sending end, and forming at least two paths of initial signals based on the split second symbol domain codes.

Further, the first initial signal generating unit may include:

a decoding signal generating subunit, configured to adjust a position order of the bit-field coding of each received signal according to a reverse algorithm of a position order adjustment algorithm of a transmitting end, so as to form a mixed bit-field decoding signal;

and the initial signal generating subunit is used for splitting the mixed bit domain decoded signal into at least two parts of codes and forming at least two paths of initial signals based on the split second bit domain codes.

Further, the decoded signal generating subunit is specifically configured to:

and carrying out forward error correction decoding on the bit domain codes of the received signals to realize the adjustment of the coding position sequence and form a mixed bit domain decoding signal.

Further, the decoded signal generating subunit is specifically configured to:

respectively carrying out LDPC decoding on the bit domain codes of the received signals to form at least two paths of third independent decoding signals;

and combining the third independent decoding signals, and performing forward error correction decoding to realize adjustment of the coding position sequence to form a mixed bit domain decoding signal.

Further, the initial signal generating subunit is specifically configured to:

splitting the mixed bit domain decoded signal into at least two paths of fourth independent decoded signals;

and respectively carrying out forward error correction decoding and BDH decoding on each fourth independent decoding signal to form at least two paths of bit domain codes, and respectively forming at least two paths of initial signals based on each bit domain code.

Further, the second initial signal generating unit is specifically configured to:

and respectively carrying out exchange reduction recombination on in-phase components and orthogonal components in two polarization states in the symbol domain codes of the received signals to form at least two paths of split second symbol domain codes, and forming at least two paths of initial signals based on the split second symbol domain codes.

Further, the number of the received signals is two, and the second initial signal generating unit is further configured to:

and respectively carrying out exchange reduction recombination on codes of in-phase components and orthogonal components in two polarization states in the symbol domain codes of the two paths of receiving signals by adopting a wrong pair coding algorithm according to the two polarization states so as to form at least two paths of split second symbol domain codes.

Further, the second initial signal generating unit is further configured to:

and converting each second symbol domain code into a bit domain code, and performing bit domain decoding processing on the bit domain code to form at least two paths of initial signals.

The product can execute the sending signal processing method of the wavelength division multiplexing optical transmission system or the receiving signal processing method of the wavelength division multiplexing optical transmission system provided by any embodiment of the disclosure, and has corresponding functional modules and beneficial effects of the execution method.

In the technical scheme of the disclosure, the collection, storage, use, processing, transmission, provision, disclosure and the like of the personal information of the related user all conform to the regulations of related laws and regulations, and do not violate the good custom of the public order.

According to an embodiment of the present disclosure, the present disclosure also provides a digital signal processing apparatus and a readable storage medium.

Embodiments of the present disclosure also provide a digital signal processing apparatus. A digital signal processing device is a device having a digital signal processing function, typically a DSP chip. The DSP chip may be an Application Specific Integrated Circuit (ASIC).

The digital signal processing apparatus may include at least one processor; and a memory communicatively coupled to the at least one processor; wherein the memory stores instructions executable by the at least one processor, the instructions being executable by the at least one processor to enable the at least one processor to perform a transmission signal processing method of a wavelength division multiplexing optical transmission system or a reception signal processing method of a wavelength division multiplexing optical transmission system provided by an embodiment of the present disclosure.

The processor and the memory in the digital signal processing device may be implemented as integrated circuits for storing the preset code for execution.

It should be understood that various forms of the flows shown above may be used, with steps reordered, added, or deleted. For example, the steps described in this disclosure may be performed in parallel, sequentially or in different orders, as long as the desired results of the technical solutions provided by this disclosure can be achieved, which are not limited herein.

The above detailed description should not be construed as limiting the scope of the disclosure. It should be understood by those skilled in the art that various modifications, combinations, sub-combinations and substitutions may be made, depending on design requirements and other factors. Any modification, equivalent replacement, and improvement made within the spirit and principle of the present disclosure should be included in the protection scope of the present disclosure.

Claims

1. A transmission signal processing method of a wavelength division multiplexing optical transmission system includes:

respectively acquiring at least two paths of initial signals;

in the process of carrying out digital signal processing on initial signals, codes of the initial signals are mixed according to a set mixing and splitting algorithm and then split to form at least two paths of signals to be transmitted; each path of signals to be transmitted comprises a partial code of each initial signal;

2. The method of claim 1, wherein the mixing and splitting the codes of each of the initial signals according to a set mixing and splitting algorithm to form at least two signals to be transmitted comprises:

mixing and splitting the bit field codes of the initial signals according to a first set mixing and splitting algorithm, and forming at least two paths of signals to be transmitted based on the split first bit field codes; and/or

And the symbol domain codes of the initial signals are mixed and split according to a second set mixing and splitting algorithm, and at least two paths of signals to be transmitted are formed based on the split first symbol domain codes.

3. The method of claim 2, wherein the bit-field coding of each of the initial signals is mixed according to a first set mixing and splitting algorithm and then split, and at least two signals to be transmitted are formed based on the split first bit-field coding, including:

adjusting the bit field coding position sequence of each initial signal to form a mixed bit field coding signal;

and splitting the mixed bit-field coding signal into at least two parts of codes, and forming at least two paths of signals to be sent based on the split first bit-field codes.

4. The method of claim 3, wherein adjusting the bit-field encoding position order of each of the initial signals to form a mixed bit-field encoded signal comprises:

5. The method of claim 4, wherein forward error correction coding the bit-field coding of each of the initial signals to effect the adjustment of the coding position order to form a mixed bit-field coded signal comprises:

6. The method according to claim 5, wherein splitting the mixed bit-domain coded signal into at least two partial codes and forming at least two signals to be transmitted based on the split first bit-domain codes comprises:

respectively carrying out low-density parity check code coding on each second independent coding signal to form at least two paths of split first bit field codes;

and processing each split first bit field code through a symbol field to form at least two signals to be transmitted.

7. The method of claim 2, wherein the symbol domain coding of each of the initial signals, the symbol domain coding being mixed according to a second predetermined mixing and splitting algorithm and then split, and the at least two signals to be transmitted being formed based on the split first symbol domain coding, comprises:

8. The method of claim 7, wherein the number of the initial signals is two, and the exchanging and recombining the in-phase component and the quadrature component in the symbol domain code of each of the initial signals in two polarization states to form the at least two split first symbol domain codes comprises:

9. The method of claim 8, before performing the exchange-recombining of the in-phase component and the quadrature component in two polarization states in the symbol-domain code of each of the initial signals, further comprising:

and acquiring the bit domain code of each initial signal, and respectively converting the bit domain code into the symbol domain code of the initial signal.

10. The method according to any one of claims 1-9, wherein the number of bands is two, C-band and L-band respectively.

11. A received signal processing method of a wavelength division multiplexing optical transmission system, comprising:

in the process of carrying out digital signal processing on received signals, the codes of the received signals are mixed and then split according to a reverse algorithm of a set mixing and splitting algorithm of a sending end to form at least two paths of initial signals; wherein each received signal comprises a partial code of each of the original signals.

12. The method of claim 11, wherein the mixing and splitting the codes of each received signal according to an inverse algorithm of a set mixing and splitting algorithm of a transmitting end to form at least two initial signals comprises:

mixing and splitting bit field codes of the received signals according to a first reverse algorithm of a first set mixing and splitting algorithm of a sending end, and forming at least two paths of initial signals based on split second bit field codes; and/or

And the symbol domain codes of the received signals are mixed and split according to a second inverse algorithm of a second set mixing and splitting algorithm of the sending end, and at least two paths of initial signals are formed based on the split second symbol domain codes.

13. The method of claim 12, wherein the bit-field coding of each of the received signals, the mixing and splitting according to a first inverse algorithm of a first set mixing and splitting algorithm at a transmitting end, and the forming at least two initial signals based on the split second bit-field coding comprises:

adjusting the bit field coding position sequence of each received signal according to the reverse algorithm of the position sequence adjustment algorithm of the transmitting end to form a mixed bit field decoding signal;

and splitting the mixed bit domain decoding signal into at least two parts of codes, and forming at least two paths of initial signals based on the split second bit domain codes.

14. The method of claim 13, wherein adjusting the bit-field encoded position order of each of the received signals according to an inverse of a position order adjustment algorithm of a transmitting end to form a hybrid bit-field decoded signal comprises:

15. The method of claim 14, wherein forward error correction decoding the bit-domain code of each of the received signals to effect the adjustment of the order of the code positions to form a hybrid bit-domain decoded signal, comprises:

and combining the third independent decoding signals, and performing forward error correction decoding to realize the adjustment of the coding position sequence to form a mixed bit domain decoding signal.

16. The method of claim 15, wherein splitting the mixed bit-domain decoded signal into at least two partial codes and forming at least two initial signals based on the split second bit-domain codes comprises:

17. The method of claim 12, wherein the symbol domain coding of each of the received signals, the mixing and splitting according to a second inverse algorithm of a second set mixing and splitting algorithm at a transmitting end, and the forming at least two initial signals based on the split second symbol domain coding comprises:

and respectively carrying out exchange reduction recombination on the in-phase component and the orthogonal component in two polarization states in the symbol domain code of each received signal to form at least two paths of split second symbol domain codes, and forming at least two paths of initial signals based on the split second symbol domain codes.

18. The method of claim 17, wherein the number of the received signals is two, and the performing exchange, reduction and recombination on the in-phase component and the quadrature component in two polarization states in the symbol domain code of each received signal respectively to form at least two split second symbol domain codes comprises:

and respectively carrying out exchange reduction recombination on the codes of the in-phase component and the orthogonal component in two polarization states in the symbol domain codes of the two paths of receiving signals by adopting a wrong pair coding algorithm according to the two polarization states so as to form at least two paths of split second symbol domain codes.

19. The method of claim 18, wherein forming at least two initial signals based on the split second symbol domain coding comprises:

20. The method according to any one of claims 11-19, wherein the number of bands is two, C-band and L-band.

21. A transmission signal processing apparatus of a wavelength division multiplexing optical transmission system, comprising:

the initial signal acquisition module is used for respectively acquiring at least two paths of initial signals;

the transmission signal generating module is used for mixing and splitting the codes of the initial signals according to a set mixing and splitting algorithm in the process of carrying out digital signal processing on the initial signals so as to form at least two signals to be transmitted; each path of signals to be transmitted comprises a partial code of each initial signal;

the optical signal generation module is used for respectively outputting each signal to be transmitted to the modems with corresponding wavelengths for modulation so as to form at least two paths of optical signals; the optical signals are used for being combined and then transmitted to an opposite end in a wavelength division multiplexing mode in the optical fiber.

22. A received signal processing apparatus of a wavelength division multiplexing optical transmission system, comprising:

the receiving signal acquisition module is used for respectively acquiring at least two paths of receiving signals which are received and demodulated from the optical fiber; wherein, the optical signals before demodulation of each receiving signal are transmitted in the optical fiber through light waves of at least two wave bands in a wavelength division multiplexing mode;

an initial signal generating module, configured to mix and split codes of each received signal according to a reverse algorithm of a set mixing and splitting algorithm of a sending end in a process of performing digital signal processing on the received signal, so as to form at least two initial signals; wherein each received signal comprises a partial code of each of the original signals.

23. A digital signal processing apparatus comprising:

at least one processor; and

the memory stores instructions executable by the at least one processor to enable the at least one processor to perform the method of any one of claims 1-10, and/or the method of any one of claims 11-20.

24. A coherent transceiver of a wavelength division multiplexed optical transmission system, comprising:

25. The transceiver of claim 24, wherein the number of digital signal processing chips is one.

26. The transceiver of claim 24, wherein the number of modems is two, for respectively demodulating and modulating a set wavelength of light waves in the C-band and a set wavelength of light waves in the L-band.

27. An optical transmission apparatus comprising:

at least one coherent transceiver of the wavelength division multiplexed optical transmission system of any of claims 24-26;

28. The optical transmission apparatus according to claim 27, wherein the number of the coherent transceivers is plural, each coherent transceiver being configured to process an optical signal corresponding to one set wavelength in a C-band and an optical signal corresponding to one set wavelength in an L-band; the pairing relation of the wavelength of the C waveband and the wavelength of the L waveband in each coherent transceiver meets the rule that the transmission quality of the signal of the C waveband is increased progressively and the transmission quality of the signal of the L waveband is decreased progressively.