CN116886201A - Optical module, forwarding network equipment and system and signal processing method - Google Patents

Abstract

The disclosure provides an optical module, a forwarding network device, a forwarding network system and a signal processing method, and relates to the technical field of communication. An optical module of the present disclosure includes: an encoded signal generation unit configured to generate a first encoded sequence from the received first signal sequence; a modulation unit configured to generate a first sequence of levels based on a predetermined probability distribution according to the first code sequence, wherein a mapping probability of a first class of levels in the predetermined probability distribution is smaller than a mapping probability of a second class of levels, and an amplitude of the first class of levels is larger than an amplitude of the second class of levels; and an optical signal transmission unit configured to generate a first optical signal according to the first level sequence and transmit the first optical signal.

Description

Optical modules, fronthaul network equipment and systems, and signal processing methods

Technical field

The present disclosure relates to the field of communication technology, in particular to an optical module, fronthaul network equipment and system, and signal processing method.

Background technique

The large-scale commercial use of 5G networks around the world has driven the rapid growth of mobile Internet business and global network traffic. In order to meet the interconnection needs of huge data, network technology is constantly iteratively updated. In 5G technology, the bearer network can be divided into fronthaul, midhaul and backhaul according to its functions. The three types of transmission systems connect the baseband unit, distributed unit and central unit. The fronthaul system is mainly responsible for realizing interconnection between the active antenna unit and the distributed unit. The midhaul system interconnects the central unit and the distributed unit, and the backhaul system connects the central unit to the 5G core network.

The fronthaul system has an important impact on the transmission performance of 5G and even 6G communication networks, and is an important component of 5G technology. Fronthaul networks drive market demand for optical modules.

The current mainstream use in 5G fronthaul networks is 25Gbps pluggable optical modules, and the packaging method is SFP28. This type of optical module can be widely used in short- and medium-distance fronthaul networks with limited space and power due to its high speed, low power consumption and small size. Facing many application scenarios such as higher-channel Massive MIMO base stations and millimeter-wave base stations in the future, the bandwidth demand of the fronthaul network will further increase. While retaining the number of existing ports and saving fiber resources, 5G fronthaul optical modules are moving forward. The first generation is developing in the direction of 50Gbps, PAM-4 (4-Level Pulse Amplitude Modulation, four-level pulse amplitude modulation) or higher data rates.

Contents of the invention

One purpose of the present disclosure is to reduce the impact of multipath interference and improve signal transmission quality in the fronthaul system.

According to an aspect of some embodiments of the present disclosure, an optical module is proposed, including: a coded signal generation unit configured to generate a first coding sequence according to a received first signal sequence; a modulation unit configured to generate a first coding sequence according to the first coding sequence, a first level sequence is generated based on a predetermined probability distribution, wherein the mapping probability of the first type of level in the predetermined probability distribution is smaller than the mapping probability of the second type of level, and the amplitude of the first type of level is greater than the second type of level. the amplitude; and an optical signal sending unit configured to generate a first optical signal according to the first level sequence and send the first optical signal.

In some embodiments, the optical module further includes: an optical signal receiving unit configured to receive a second optical signal and generate a second level sequence according to the second optical signal; and a demodulation unit configured to generate a second level sequence according to the second optical signal. and a predetermined probability distribution to determine the second coding sequence; and a signal sequence generating unit configured to generate a second signal sequence according to the second coding sequence.

In some embodiments, the encoded signal generation unit includes: a distribution matcher configured to generate a first PAM-4 positive level sequence according to the first signal sequence based on a fixed component distribution matching algorithm; a binary label subunit configured In order to utilize binary reflective Gray coding, a sequence to be encoded is generated based on the first PAM-4 positive level sequence of the multi-ary system; and the encoding subunit is configured to perform FEC (Forward Error Correction) on the sequence to be encoded. ) encoding to generate the first encoding sequence.

In some embodiments, the signal sequence generation unit includes: a decoding subunit configured to perform FEC decoding on the second encoding sequence to generate a decoding sequence; a binary decoding subunit configured to generate a multiplex decoding sequence according to the binary decoding sequence. a binary second PAM-4 positive level sequence; a distributed dematcher configured to generate a second signal sequence according to the second PAM-4 positive level sequence.

In some embodiments, the first type of level includes a first positive level and a first negative level, wherein the first positive level and the first negative level have the same absolute value of amplitude and the same mapping probability; the second type of level includes The second positive level and the second negative level, wherein the amplitude absolute values of the second positive level and the second negative level are the same, and the mapping probabilities are the same.

According to an aspect of some embodiments of the present disclosure, it is proposed that the optical signal receiving unit is configured to receive a second optical signal and generate a second level sequence according to the second optical signal; and the demodulation unit is configured to generate a second level sequence according to the second optical signal. sequence and a predetermined probability distribution to determine the second coding sequence, wherein the mapping probability of the first type of level in the predetermined probability distribution is smaller than the mapping probability of the second type of level, and the amplitude of the first type of level is greater than that of the second type of level. amplitude; and a signal sequence generating unit configured to generate a second signal sequence according to the second encoding sequence.

According to an aspect of some embodiments of the present disclosure, a fronthaul network device is proposed, including: any one of the above optical modules; and a multiplexer and demultiplexer, the first side of which is connected to the optical module and configured to receive light from the optical module. The signal is combined into one optical signal and output from the second side.

In some embodiments, the optical module is any of the above optical modules including an optical signal receiving unit; the multiplexer and demultiplexer are also configured to receive optical signals from the optical network through the second side and demultiplex them into multiple optical signals. Finally, according to the wavelength of each optical signal, it is sent to the optical module corresponding to the wavelength through the port on the first side.

According to an aspect of some embodiments of the present disclosure, a fronthaul network system is proposed, including: an active antenna unit and a distribution unit, each including any one of the above fronthaul network devices; and an optical fiber located between the active antenna unit and the distribution unit. between the active antenna unit and the second side port of the multiplexer and splitter of the distribution unit.

According to an aspect of some embodiments of the present disclosure, a signal processing method is proposed, including: generating a first coding sequence according to a received first signal sequence; generating a first level sequence based on a predetermined probability distribution according to the first coding sequence, Wherein, the mapping probability of the first type of level in the predetermined probability distribution is less than the mapping probability of the second type of level, and the amplitude of the first type of level is greater than the amplitude of the second type of level; and the first level is generated according to the first level sequence. optical signal and sends the first optical signal.

In some embodiments, the method further includes: receiving a second optical signal, generating a second level sequence according to the second optical signal; determining a second coding sequence according to the second level sequence and the predetermined probability distribution; and according to the second The encoding sequence generates a second signal sequence.

In some embodiments, generating the first coding sequence according to the received first signal sequence includes: generating a first PAM-4 positive level sequence based on a fixed component distribution matching algorithm according to the first signal sequence; using binary reflective Gray coding, Generate a sequence to be encoded based on the first PAM-4 positive level sequence in multi-ary system; and perform FEC encoding on the sequence to be encoded to generate a first encoding sequence.

In some embodiments, generating the second signal sequence according to the second coding sequence includes: performing FEC decoding on the second coding sequence to generate a decoding sequence; and generating a multi-ary second PAM-4 positive signal according to the binary decoding sequence. a flat sequence; and generating a second signal sequence based on a second PAM-4 positive level sequence.

In some embodiments, the method further includes: receiving first optical signals from multiple optical modules, multiplexing them into one optical signal, and then outputting the first optical signals.

In some embodiments, the method further includes: receiving one optical signal, demultiplexing it into multiple second optical signals, and sending the second optical signal to the optical module corresponding to the wavelength through the port on the first side according to the wavelength of the second optical signal.

According to an aspect of some embodiments of the present disclosure, a signal processing method is proposed, including: receiving a second optical signal, generating a second level sequence according to the second optical signal; and determining, according to the second level sequence and a predetermined probability distribution, a second encoding sequence, wherein the mapping probability of the first type of level in the predetermined probability distribution is less than the mapping probability of the second type of level, and the amplitude of the first type of level is greater than the amplitude of the second type of level; and according to the second encoding The sequence generates a second signal sequence.

Description of the drawings

The drawings described here are used to provide a further understanding of the present disclosure and constitute a part of the present disclosure. The illustrative embodiments of the present disclosure and their descriptions are used to explain the present disclosure and do not constitute an improper limitation of the present disclosure. In the attached picture:

Figure 1 is a schematic diagram of some embodiments of an optical module of the present disclosure.

FIG. 2 is a schematic diagram of other embodiments of the optical module of the present disclosure.

Figure 3 is a schematic diagram of further embodiments of the optical module of the present disclosure.

FIG. 4 is a schematic diagram of some embodiments of preset probabilities of the optical module of the present disclosure.

Figure 5 is a schematic diagram of some embodiments of fronthaul network equipment of the present disclosure.

Figure 6 is a schematic diagram of some embodiments of the fronthaul network system of the present disclosure.

Figure 7 is a flowchart of some embodiments of the signal processing method of the present disclosure.

Figure 8 is a flow chart of other embodiments of the signal processing method of the present disclosure.

Detailed ways

The technical solution of the present disclosure will be described in further detail below through the accompanying drawings and examples.

The 4G fronthaul network is deployed using the D-RAN (Distributed Radio Access Network) architecture, that is, the remote radio frequency unit and the baseband processing unit are connected using gray optical fiber direct drive, and the transmission distance is generally 100m. about. In the 5G fronthaul network architecture, a large number of C-RAN (Centralized, Cooperative, Cloud and clean RAN, centralized, collaborative, cloud computing architecture, green wireless access network) methods are deployed with centralized baseband processing units. Under this architecture, the baseband processing units will be placed in a centralized computer room, and the active antenna unit and the baseband processing unit are connected using gray optical fiber direct drive or colored optical interconnection. The centralized deployment of baseband processing units will inevitably increase the end-to-end transmission distance of the 5G fronthaul system. The transmission distance of the existing 5G fronthaul system is generally around 10km.

As the optical module rate and fronthaul network transmission distance increase, especially when the PAM-4 modulation format is used, the multipath interference effect of the transmission system will cause serious interference to the performance of the transmission system. The multipath interference effect is an interference phenomenon caused by the end-face reflection caused by the dirty optical module or optical fiber end-face at the connector. The extra optical signal generated superposes the original signal at the receiving end. It will affect IM-DD( Intensity Modulation Direct Detection (Intensity Modulation Direct Detection) system’s detection of power causes bit errors to occur. Compared with the NRZ (Non-Return to Zero, non-return to zero code) modulation format, PAM-4 has a smaller Euclidean distance between signal points, so it is more susceptible to the multipath interference effect, and the higher the level, the The greater the noise.

In response to the above problems, the present disclosure proposes an optical module, fronthaul network equipment and system, and signal processing method to reduce multipath interference effects and reduce the bit error rate of the fronthaul network.

A schematic diagram of some embodiments of the optical module of the present disclosure is shown in Figure 1.

The coded signal generating unit 111 can generate a first coded sequence according to the received first signal sequence. In some embodiments, the first signal sequence is a signal sequence from a preceding network node of the optical module. In some embodiments, the coded signal generation unit codes the first signal sequence to generate a coded signal, which is sent to the modulation unit 112 for signal modulation.

The modulation unit 112 can generate a first level sequence based on a predetermined probability distribution according to the first coding sequence, wherein the mapping probability of the first type of level in the predetermined probability distribution is less than the mapping probability of the second type of level, and the first type of level The amplitude is greater than the amplitude of the second type level.

The optical signal sending unit 113 can generate a first optical signal according to the first level sequence and send the first optical signal through the optical signal sending interface of the optical module.

Such an optical module uses an improved hardware structure and modulates the coding sequence to reduce the mapping probability of high-level signals and increase the mapping probability of low-level signals, taking advantage of the advantages of high-level signals relative to low-level signals. The signal is more susceptible to the influence of multipath interference noise, which effectively reduces the impact of multipath interference on the transmitted signal and helps reduce the bit error rate.

Schematic diagrams of other embodiments of optical modules of the present disclosure are shown in FIG. 2 .

The optical signal receiving unit 221 can receive the second optical signal and generate a second level sequence according to the second optical signal. In some embodiments, the second optical signal is an optical signal received through an optical signal receiving interface of the optical module.

The demodulation unit 222 can determine the second coding sequence according to the second level sequence and the predetermined probability distribution. In some embodiments, the mapping probability of the first type of level in the predetermined probability distribution is less than the mapping probability of the second type of level, and the amplitude of the first type of level is greater than the amplitude of the second type of level.

The signal sequence generation unit 223 can obtain the second coding sequence generated after demodulation by the demodulation unit 222, and generate a second signal sequence according to the second coding sequence.

Such an optical module can use the improved hardware structure to demodulate optical signals modulated with a predetermined mapping probability, and can be used in conjunction with the optical module shown in Figure 1 to achieve the reception and transmission of signal sequences. By reducing the mapping probability of high-level signals in the optical signal and increasing the mapping probability of low-level signals, the impact of multipath interference on the transmitted signal is effectively reduced, which is beneficial to reducing the bit error rate.

In some embodiments, the optical module can have the structures in the embodiments shown in Figures 1 and 2 at the same time, thereby reducing the impact of multipath interference in the two-way transmission of optical signals and reducing the bit error rate in two-way transmission of optical signals.

In some embodiments, as shown in FIG. 3 , the encoding signal generation unit may include a distribution matcher 3111, a binary label subunit 3112, and an encoding subunit 3113.

The distribution matcher 3111 is capable of generating a first PAM-4 positive level sequence with an unequal distribution based on a fixed component distribution matching algorithm based on the first signal sequence. The binary tag subunit 3112 can use binary reflective Gray coding to convert the multi-ary first PAM-4 positive level sequence into a sequence to be encoded with unequal probability distribution. The encoding subunit 3113 can perform FEC encoding on the to-be-encoded sequence to generate a first encoding sequence. In some embodiments, in order to be compatible with the existing industry chain, the channel coding method is KP4. Each redundant bit generated by FEC corresponds to a multi-ary PAM-4 level sequence one-to-one, and the redundant bit "0" is specified. Indicates positive amplitude, redundant bit "1" indicates negative amplitude. By one-to-one correspondence between the positive and negative redundant bits and the multi-ary PAM-4 level sequence, a PAM-4 signal sequence that satisfies the unequal distribution can be obtained. Such optical modules are capable of generating PAM-4 signals.

The modulation unit 312 can generate a first level sequence based on a predetermined probability distribution according to the first encoding sequence. In some embodiments, the mapping probability of the first type of level in the predetermined probability distribution is less than the mapping probability of the second type of level, and the amplitude of the first type of level is greater than the amplitude of the second type of level. In some embodiments, the first type of level includes a first positive level and a first negative level, wherein the first positive level and the first negative level have the same absolute value of amplitude and the same mapping probability; the second type of level includes The second positive level and the second negative level, wherein the amplitude absolute values of the second positive level and the second negative level are the same, and the mapping probabilities are the same. In such an optical module, levels with the same amplitude but different polarities have equal probabilities, thereby reducing the difficulty of subsequent processing.

For example, the predetermined probability distribution may be as shown in Figure 4. The mapping probability of amplitudes with relatively high levels, such as -3 and 3, is smaller than the amplitudes with relatively high levels, such as -1 and 1. The redundant bits representing positive and negative have a one-to-one correspondence with the multi-ary PAM-4 level sequence, and a PAM-4 signal sequence that satisfies the unequal distribution can be obtained.

The optical signal sending unit 313 can generate a first optical signal according to the first level sequence and send the first optical signal.

The optical module in the embodiment shown above can generate PAM-4 signals based on signal sequences, which improves the matching degree with the existing network; after passing through the probabilistic constellation shaping module, the PAM-4 signals generated by the optical module effectively reduce the high Level mapping probability increases the mapping probability of low-level signals, effectively alleviating the small Euclidean distance between signal points due to PAM-4 compared to NRZ (Not Return to Zero, non-return to zero code) modulation format. , which is more susceptible to the multipath interference effect and improves the signal transmission quality of the fronthaul transmission system.

In some embodiments, as shown in Figure 3, the optical signal receiving unit 321 of the optical module can receive the second optical signal and generate a second level sequence according to the second optical signal.

The demodulation unit 322 can determine the second coding sequence according to the second level sequence and the predetermined probability distribution. In some embodiments, the mapping probability of the first type of level in the predetermined probability distribution is less than the mapping probability of the second type of level, and the amplitude of the first type of level is greater than the amplitude of the second type of level. In some embodiments, the first type of level includes a first positive level and a first negative level, wherein the first positive level and the first negative level have the same absolute value of amplitude and the same mapping probability; the second type of level includes The second positive level and the second negative level, wherein the amplitude absolute values of the second positive level and the second negative level are the same, and the mapping probabilities are the same. In some embodiments, the predetermined probability distribution may be as shown in Figure 4.

In some embodiments, as shown in Figure 3, the signal sequence generation unit includes a decoding sub-unit 3231, a binary de-labeling sub-unit 3232 and a distribution de-matcher 3233.

The decoding subunit 3231 can perform FEC decoding on the second encoding sequence from the demodulation unit 322 to generate a decoding sequence.

The binary decoding subunit 3232 can generate a multi-ary second PAM-4 positive level sequence according to the binary decoding sequence.

The distribution dematcher 3233 is capable of generating a second signal sequence based on the second PAM-4 positive level sequence.

The demodulation and decoding functions of such an optical module can analyze the optical signal processed by probabilistic constellation shaping. Its analysis operation matches the operation of performing probabilistic constellation shaping to generate optical signals, realizing the PAM-4 signal based on probabilistic constellation shaping. Receive and transmit, effectively reducing the impact of multipath interference on the transmitted signal, which is beneficial to reducing the bit error rate.

In some embodiments, as shown in Figure 3, the optical module includes a distribution matcher, a binary label subunit, a coding subunit, a modulation unit, and an optical signal transmitting unit, as well as an optical signal receiving unit, a decoding subunit, and a binary decoding subunit. unit, distribution dematcher and demodulation unit.

By cooperating with the opposite end optical module, such an optical module can generate PAM-4 signals and reduce the impact of multipath interference noise in its transmission; it can receive and analyze the light generated by the opposite end optical module and mapped through the probabilistic constellation. signal, improving the quality of two-way transmission of the fronthaul system.

Compared with solutions in related technologies, the optical module in this disclosure improves the hardware design of the 50Gbps SFP56 optical module, reduces the transmission optical power requirements required by the transmission system under the same spectrum efficiency, and is conducive to reducing the manufacturing cost of the optical module. . At the same time, the PAM-4 signal based on probabilistic constellation shaping reduces the number of high-level occurrences, so it can bring coding shaping gain to the transmission system, suppress the adverse effects of multipath interference effects on high-level signals, and reduce the transmission system The power cost enables the 5G fronthaul system to have better bit error performance.

A schematic diagram of some embodiments of fronthaul network equipment of the present disclosure is shown in Figure 5. The fronthaul network equipment includes multiple optical modules, such as optical modules 511 to 51n, where n is an integer greater than 1. The optical module can be any of the ones mentioned above.

In some embodiments, the first side of the multiplexer and demultiplexer 52 is connected to the optical module through multiple interfaces, wherein each interface is connected to one optical module. The multiplexer/demultiplexer 52 combines the optical signals from the plurality of optical modules and sends them out through the second side, thereby realizing the multiplexing of the optical signals from the multiple optical modules and sending them out.

In some embodiments, the multiplexer and demultiplexer 52 can also receive optical signals from the optical network through the second side, demultiplex the optical signals into multiple optical signals, and then pass the optical signals through the first side according to the wavelength of each optical signal. The port is sent to the optical module corresponding to the wavelength, thereby demultiplexing the optical signal from the optical network and passing it to the target optical module.

In such fronthaul network equipment, the optical module modulates the coding sequence to reduce the mapping probability of high-level signals and increase the mapping probability of low-level signals, taking advantage of the fact that high-level signals are more reliable than low-level signals. It is easily affected by multipath interference noise, which effectively reduces the impact of multipath interference on the transmitted signal, which is beneficial to reducing the bit error rate; while suppressing the multipath interference effect of the system, only smaller transmission signal light is required The same spectrum efficiency can be achieved with the same power, which can effectively reduce the design complexity and production cost of optical modules, and help reduce the deployment cost of 5G fronthaul network.

A schematic diagram of some embodiments of the fronthaul network system of the present disclosure is shown in Figure 6.

The fronthaul network system includes active antenna units and distribution units.

The optical fiber is located between the active antenna unit and the distribution unit, and connects the active antenna unit and the second side port of the multiplexer and demultiplexer of the distribution unit. In some embodiments, the light connected to the multiplexer and splitter of the active antenna unit passes through the optical distribution frame and then reaches the site fiber distribution box through long-distance transmission; the optical fiber of the site fiber distribution box is connected to the multiplexer and splitter of the distribution unit. wave device.

In some embodiments, the active antenna unit is a fronthaul network device. The fronthaul network device may be the fronthaul network device mentioned in this disclosure. The optical module of the network device may be any of the above mentioned devices equipped with the present disclosure. The optical module of the modulation unit; the distribution unit is a fronthaul network device. The fronthaul network device can be the fronthaul network device mentioned in this disclosure. The optical module of the network device can be any one of the above mentioned devices. Optical module of the demodulation unit. Such a fronthaul system can improve the quality of data transmission from the distribution unit to the active antenna unit and reduce the noise impact of multipath interference in this direction.

In some embodiments, the active antenna unit is a fronthaul network device. The fronthaul network device may be the fronthaul network device mentioned in this disclosure. The optical module of the network device may be any of the above mentioned devices equipped with the present disclosure. The optical module of the demodulation unit; the distribution unit is a fronthaul network device. The fronthaul network device can be the fronthaul network device mentioned in this disclosure. The optical module of the network device can be any of the above mentioned devices equipped with this disclosure. The optical module of the medium modulation unit. Such a fronthaul system can improve the quality of data transmission from the distribution unit to the active antenna unit and reduce the noise impact of multipath interference in this direction.

In some embodiments, the active antenna unit and distribution unit are the fronthaul network equipment mentioned in this disclosure, and their optical modules support both probabilistic constellation shaping processing of signals and analysis of probabilistic constellation shaping signals, thereby improving uplink and downlink dual The quality of upward data transmission reduces the noise impact of multipath interference in both directions.

In the fronthaul network system in the embodiment of the present disclosure, during the formation process of optical signals, the mapping probability of high-level signals is reduced, the mapping probability of low-level signals is increased, and the mapping probability of high-level signals relative to low-level signals is utilized. The signal is more susceptible to the influence of multipath interference noise, which effectively reduces the impact of multipath interference on the transmitted signal, which is beneficial to reducing the bit error rate; there is no need to increase the design complexity of the optical module, saving single module production costs and reducing Reduce the cost of 5G network construction.

A flowchart of some embodiments of the signal processing method of the present disclosure is shown in Figure 7.

In step 711, a first coding sequence is generated according to the received first signal sequence. In some embodiments, the first signal sequence is a signal sequence from a preceding network node of the optical module.

In step 712, according to the first encoding sequence, a first level sequence is generated based on a predetermined probability distribution, wherein the mapping probability of the first type of level in the predetermined probability distribution is less than the mapping probability of the second type of level, and the first type of level The amplitude of the level is greater than the amplitude of the second type of level. In some embodiments, the first positive level and the first negative level have the same absolute value of amplitude and the same mapping probability; the second type of level includes a second positive level and a second negative level, where the second positive level and the The absolute values of the amplitudes of the two negative levels are the same, and the mapping probabilities are the same.

In step 713, a first optical signal is generated according to the first level sequence and the first optical signal is sent.

Based on the method in the embodiment shown above, through the modulation of the coding sequence, the mapping probability of high-level signals is reduced, the mapping probability of low-level signals is increased, and the mapping probability of high-level signals relative to low-level signals is utilized. The signal is more susceptible to the influence of multipath interference noise, which effectively reduces the impact of multipath interference on the transmitted signal and helps reduce the bit error rate.

A flow chart of other embodiments of the signal processing method of the present disclosure is shown in FIG. 8 .

In step 821, a second optical signal is received, and a second level sequence is generated according to the second optical signal. In some embodiments, the second optical signal is an optical signal received through an optical signal receiving interface of the optical module.

In step 822, a second coding sequence is determined based on the second level sequence and the predetermined probability distribution. In some embodiments, the mapping probability of the first type of level in the predetermined probability distribution is less than the mapping probability of the second type of level, and the amplitude of the first type of level is greater than the amplitude of the second type of level. In some embodiments, the first positive level and the first negative level have the same absolute value of amplitude and the same mapping probability; the second type of level includes a second positive level and a second negative level, where the second positive level and the The absolute values of the amplitudes of the two negative levels are the same, and the mapping probabilities are the same.

In step 823, a second signal sequence is generated according to the second encoding sequence.

Through the method in the embodiment shown above, the demodulation of the optical signal modulated with the predetermined mapping probability can be realized. When matched with the signal processing method in the embodiment shown in Figure 7, the reception and reception of the signal sequence can be realized. hair. Since the optical signal reduces the mapping probability of high-level signals and increases the mapping probability of low-level signals during the modulation process, it effectively reduces the impact of multipath interference on the transmitted signal and helps reduce the bit error rate.

Up to this point, the present disclosure has been described in detail. To avoid obscuring the concepts of the present disclosure, some details that are well known in the art have not been described. Based on the above description, those skilled in the art can completely understand how to implement the technical solution disclosed here.

The methods and apparatus of the present disclosure may be implemented in many ways. For example, the methods and devices of the present disclosure can be implemented through software, hardware, firmware, or any combination of software, hardware, and firmware. The above order for the steps of the methods is for illustration only, and the steps of the methods of the present disclosure are not limited to the order specifically described above unless otherwise specifically stated. Furthermore, in some embodiments, the present disclosure may also be implemented as programs recorded in recording media, and these programs include machine-readable instructions for implementing methods according to the present disclosure. Thus, the present disclosure also covers recording media storing programs for executing methods according to the present disclosure.

It should be noted that the terms "first", "second", etc. in the description, claims and drawings of the present disclosure are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It is to be understood that the data so used are interchangeable under appropriate circumstances so that the embodiments of the disclosure described herein can be practiced in sequences other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, e.g., a process, method, system, product, or apparatus that encompasses a series of steps or units and need not be limited to those explicitly listed. Those steps or elements may instead include other steps or elements not expressly listed or inherent to the process, method, product or apparatus.

Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present disclosure and not to limit it; although the present disclosure has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that the present disclosure can still be modified Modifications to the specific embodiments disclosed or equivalent replacement of some technical features without departing from the spirit of the technical solution disclosed shall be included in the scope of the technical solution claimed by the present disclosure.

Claims (16)

1. An optical module, including: a coded signal generating unit configured to generate a first coded sequence according to the received first signal sequence; a modulation unit configured to generate a first level sequence based on a predetermined probability distribution according to the first coding sequence, wherein the mapping probability of the first type of level in the predetermined probability distribution is less than the mapping probability of the second type of level, so The amplitude of said first type of level is greater than the amplitude of said second type of level; and An optical signal sending unit is configured to generate a first optical signal according to the first level sequence and send the first optical signal. 2. The optical module according to claim 1, further comprising: An optical signal receiving unit configured to receive a second optical signal and generate a second level sequence according to the second optical signal; a demodulation unit configured to determine a second coding sequence according to the second level sequence and the predetermined probability distribution; and A signal sequence generating unit configured to generate a second signal sequence according to the second encoding sequence. 3. The optical module according to claim 1, wherein the encoded signal generating unit includes: a distribution matcher configured to generate a first four-level pulse amplitude modulation PAM-4 positive level sequence based on the fixed component distribution matching algorithm according to the first signal sequence; A binary tag subunit configured to utilize binary reflective Gray coding to generate a sequence to be encoded based on the first PAM-4 positive level sequence of the multi-ary system; and The encoding subunit is configured to perform forward error correction code FEC encoding on the sequence to be encoded, and generate the first encoding sequence. 4. The optical module according to claim 2, wherein the signal sequence generating unit includes: A decoding subunit configured to perform FEC decoding on the second encoding sequence and generate a decoding sequence; A binary decoding subunit configured to generate a multi-ary second PAM-4 positive level sequence according to the binary decoding sequence; A distributed dematcher configured to generate a second signal sequence according to the second PAM-4 positive level sequence. 5. The optical module according to claim 1 or 2, wherein, The first type of level includes a first positive level and a first negative level, wherein the first positive level and the first negative level have the same absolute amplitude value and the same mapping probability; The second type of level includes a second positive level and a second negative level, wherein the second positive level and the second negative level have the same absolute amplitude value and the same mapping probability. 6. An optical module, including: An optical signal receiving unit configured to receive a second optical signal and generate a second level sequence according to the second optical signal; a demodulation unit configured to determine a second coding sequence according to the second level sequence and the predetermined probability distribution, wherein the mapping probability of the first type of level in the predetermined probability distribution is less than the second type of level The mapping probability is that the amplitude of the first type of level is greater than the amplitude of the second type of level; and A signal sequence generating unit configured to generate a second signal sequence according to the second encoding sequence. 7. A fronthaul network device, including: The optical module according to any one of claims 1 to 5; and A multiplexer and demultiplexer, the first side of which is connected to the optical module, is configured to receive the optical signal from the optical module, multiplex it into one optical signal and output it from the second side. 8. The fronthaul network device according to claim 7, wherein the optical module is the optical module according to any one of claims 2, 4 or 6; The multiplexer and demultiplexer are also configured to receive optical signals from the optical network through the second side. After demultiplexing into multiple optical signals, according to the wavelength of each optical signal, the wavelength is sent to the port through the first side. Corresponding optical module. 9. A fronthaul network system, including: The active antenna unit and the distribution unit respectively include the fronthaul network equipment according to claim 7 or 8; and An optical fiber is located between the active antenna unit and the distribution unit, and connects the active antenna unit and the second side port of the multiplexer and demultiplexer of the distribution unit. 10. A signal processing method, comprising: Generate a first coding sequence according to the received first signal sequence; According to the first coding sequence, a first level sequence is generated based on a predetermined probability distribution, wherein the mapping probability of the first type of level in the predetermined probability distribution is less than the mapping probability of the second type of level, and the first type of level The amplitude is greater than the amplitude of said second category level; and Generate a first optical signal according to the first level sequence and send the first optical signal. 11. The method of claim 10, further comprising: Receive a second optical signal and generate a second level sequence according to the second optical signal; determining a second coding sequence based on the second level sequence and the predetermined probability distribution; and A second signal sequence is generated based on the second coding sequence. 12. The method according to claim 10, wherein generating the first coding sequence according to the received first signal sequence comprises: According to the first signal sequence, a first PAM-4 positive level sequence is generated based on a fixed component distribution matching algorithm; Using binary reflective Gray coding, generate a sequence to be encoded according to the first PAM-4 positive level sequence in multi-ary system; and Perform forward error correction code FEC encoding on the sequence to be encoded to generate the first encoding sequence. 13. The method according to claim 11 or 12, wherein generating a second signal sequence according to the second coding sequence includes: Perform FEC decoding on the second encoding sequence to generate a decoding sequence; Generate a multi-ary second PAM-4 positive level sequence according to the binary decoding sequence; and A second signal sequence is generated based on the second PAM-4 positive level sequence. 14. The method according to any one of claims 10-12, further comprising: The first optical signals from multiple optical modules are received, combined into one optical signal, and then output. 15. The method of claim 11 or 13, further comprising: Receive one optical signal and split it into multiple second optical signals; According to the wavelength of the second optical signal, it is sent to the optical module corresponding to the wavelength through the port on the first side. 16. A signal processing method, comprising: Receive a second optical signal and generate a second level sequence according to the second optical signal; Determine a second coding sequence according to the second level sequence and a predetermined probability distribution, wherein the mapping probability of the first type of level in the predetermined probability distribution is less than the mapping probability of the second type of level, and the first type of level The amplitude is greater than the amplitude of said second category level; and A second signal sequence is generated based on the second coding sequence.