WO2024037219A1

WO2024037219A1 - Light-emitting apparatus, and method for emitting optical signal

Info

Publication number: WO2024037219A1
Application number: PCT/CN2023/104205
Authority: WO
Inventors: 李博睿; 林华枫
Original assignee: 华为技术有限公司
Priority date: 2022-08-18
Filing date: 2023-06-29
Publication date: 2024-02-22
Also published as: CN117639946A

Abstract

Provided in the present application are a light-emitting apparatus and a method for emitting an optical signal. The apparatus comprises: a laser device, which is used for emitting a first optical signal and a second optical signal, the first optical signal being an optical signal which is output by the laser device forwards, the second optical signal being an optical signal which is output by the laser device backwards, and information which is carried in the second optical signal being the same as information which is carried in the first optical signal; a photoelectric detector, which is used for performing photoelectric conversion processing on the second optical signal, so as to obtain a first current signal; a service data unit, which is used for receiving user service data and generating a first digital signal; and a pre-compensation unit, which is used for performing pre-compensation on the first digital signal by using the first current signal, so as to obtain a second digital signal, and performing digital-to-analog conversion processing on the second digital signal to obtain a second current signal, wherein the laser device is further used for emitting a third optical signal by using the second current signal. The apparatus disclosed in the present application enables a signal to be accurately pre-equalized in real time in a quick and adaptive manner.

Description

A light emitting device and a method for emitting light signals

This application claims the priority of the Chinese patent application submitted to the State Intellectual Property Office of China on August 18, 2022, with application number 202210995369.5 and application title "An optical emitting device and a method for emitting optical signals", and its entire content is approved by This reference is incorporated into this application.

Technical field

The present application relates to the field of optical communication technology, and more specifically, to a light emitting device and a method for transmitting an optical signal.

Background technique

With the evolution of passive optical network (PON) and data center communications, the signal rate is getting higher and higher. For example, the rate of the next generation passive optical network is about 50 gigabits per second (Gbps), which means that the optical network terminal (ONT) needs to be able to transmit a non-return-to-zero (non-zero) baud rate (G Baud) of 50 -The ability to return zero, NRZ) signals. The current single-wavelength rate of data center communication is about 100Gbps, which requires the transmitter of the optical module in the data center to have the ability to transmit 50G Baud four-level pulse amplitude modulation (PAM4) signals.

However, optical modules in data centers, especially optical modules in passive optical network terminals, are very cost-sensitive. The industry tends to use uncooled, low-cost optical emission based on direct modulated lasers (DML). Machine plan. This leads to the current high-speed, uncooled DML optical transmitter facing two major problems: the first is that the bandwidth of DML itself is difficult to support 50GBaud signal transmission at full temperature, and a certain degree of pre-compensation is required; the second is that When the temperature changes, the DML chip bandwidth will change. For example, when the temperature rises, the DML chip bandwidth becomes smaller and the light output power decreases. Subsequently, the eye diagram extinction ratio decreases, thereby reducing performance.

Therefore, there is an urgent need for an optical transmitting device and a method for transmitting optical signals that can accurately pre-equalize signals in real-time, quickly and adaptively.

Contents of the invention

The present application provides an optical transmitting device and a method for transmitting optical signals, which can accurately pre-equalize signals in real time, quickly and adaptively.

In a first aspect, a light emitting device is provided. The device includes a laser, a photoelectric detector, a service data unit and a pre-compensation unit, wherein: the laser is used to emit a first optical signal and a second optical signal, the first optical signal is the optical signal outputted forward by the laser, and the second optical signal The signal is an optical signal output from the back of the laser, and the information carried by the second optical signal is the same as the information carried by the first optical signal; the photodetector is used to perform photoelectric conversion processing on the second optical signal to obtain the first current signal; The service data unit is used to receive user service data and generate a first digital signal; the pre-compensation unit is used to use the first current signal to pre-compensate the first digital signal to obtain a second digital signal, and perform digital-analog processing on the second digital signal. The conversion process obtains a second current signal; the laser is also used to use the second current signal to emit a third optical signal.

The device disclosed in this application obtains all the information of the first optical signal by acquiring the backlight signal corresponding to the first optical signal. Furthermore, it performs pre-compensation based on all the information of the first optical signal, and can achieve real-time, fast, Adaptively pre-equalize signals accurately.

In connection with the first aspect, in some implementations of the first aspect, the working bandwidth of the photodetector is greater than or equal to the bandwidth required to recover the information carried by the second optical signal from the second optical signal, or, the photodetector The operating bandwidth is greater than or equal to a certain proportion of the first optical signal bandwidth, such as 0.75 times, 0.8 times, etc.

With reference to the first aspect, in some implementations of the first aspect, the pre-compensation unit includes a first pre-compensation unit and a second pre-compensation unit, wherein: the first pre-compensation unit is used to use the first electrical signal to look up the table to obtain The first pre-compensation information is used to indicate the first pre-compensation coefficient; the second pre-compensation unit is used to use the first pre-compensation information to pre-compensate the first digital signal to obtain the second digital signal. The second digital signal undergoes digital-to-analog conversion processing to obtain a second current signal. In this way, the corresponding pre-compensation coefficient can be obtained according to the first pre-compensation information, the signal can be pre-compensated according to the pre-compensation parameter, and the signal can be accurately pre-equalized in real time, quickly and adaptively.

In conjunction with the first aspect, in some implementations of the first aspect, the first pre-compensation information includes an index of the first pre-compensation coefficient, or the first pre-compensation coefficient.

In connection with the first aspect, in some implementations of the first aspect, the first pre-compensation unit includes a first converter, a first filter, a second filter, a first power detection unit, a second power detection unit, an error Comparing unit and processor, the first filter and the second filter allow signals to pass through different frequency bands, wherein: the first converter is used to convert the first current signal into the first voltage signal; the first filter is used to The first voltage signal is filtered to obtain the first signal to be detected; the second filter is used to filter the first voltage signal to obtain the second signal to be detected; the first power detection unit is used to filter the first signal to be detected. The detection signal is subjected to power detection to obtain the first detection result; the second power detection unit is used to perform power detection on the second signal to be detected to obtain the second detection result; the error comparison unit is used to compare the first detection result and the second detection result. The detection results are subjected to error comparison processing to obtain the first target gain; the processor is configured to use the first target gain to look up the table to obtain the first pre-compensation information. In this way, the two frequency bands of the first voltage signal converted from the first optical signal are processed through two filters to obtain two detection results. The final pre-compensation coefficient is further obtained based on the two detection results, which can be done in real time. , quickly and adaptively perform accurate pre-equalization of signals.

In conjunction with the first aspect, in some implementations of the first aspect, the first pre-compensation unit further includes a memory, the memory is pre-configured with look-up table information, and the look-up table information includes correspondences between multiple target gains and multiple pre-compensation information. , the plurality of target gains include the first target gain, and the plurality of pre-compensation information include the first pre-compensation information; the processor is specifically configured to use the first target gain to obtain the first pre-compensation information from the lookup table information, the first pre-compensation information The information is used to indicate the first pre-compensation coefficient corresponding to the first target gain. In this way, by presetting the lookup table, the detection result of the first optical signal can be used, the lookup table can be used to obtain the corresponding compensation coefficient, and the signal can be accurately pre-equalized in real time, quickly and adaptively.

Combined with the first aspect, in some implementations of the first aspect, the processor includes a central processor (central processor unit, CPU), a digital signal processor (digital signal processor, DSP) or a micro control unit (micro controller unit, MCU).

In connection with the first aspect, in some implementations of the first aspect, the second pre-compensation unit includes a digital-to-analog converter and a driver, wherein: the digital-to-analog converter is used to perform processing on the first digital signal using the first pre-compensation information. The pre-compensation process is used to obtain a second digital signal, and the second digital signal is subjected to photoelectric conversion processing to obtain a third current signal; the driver is used to amplify the third current signal to obtain the second current signal.

In conjunction with the first aspect, in some implementations of the first aspect, the digital-to-analog converter includes a digital signal processor DSP, The DSP is used to perform pre-compensation processing on the first digital signal using the first pre-compensation information to obtain the second digital signal, and the digital-to-analog converter is specifically used to obtain the third current signal using the second digital signal.

In connection with the first aspect, in some implementations of the first aspect, the driver is also used to generate a fourth current signal, the fourth current signal is a bias current, and the laser is specifically used to emit using the second current signal and the fourth current signal. Third light signal.

In the second aspect, a method of transmitting optical signals is provided. The method includes: emitting a first optical signal and a second optical signal. The first optical signal is an optical signal outputted forward by the laser. The second optical signal is an optical signal outputted backward by the laser. The information carried by the second optical signal is the same as the optical signal carried by the second optical signal. The information carried by the first optical signal is the same; perform photoelectric conversion processing on the second optical signal to obtain the first current signal; receive user service data and generate the first digital signal; use the first current signal to perform pre-compensation processing on the first digital signal Obtain a second digital signal, perform digital-to-analog conversion processing on the second digital signal to obtain a second current signal, and use the second current signal to emit a third optical signal.

The method disclosed in this application obtains all the information of the first optical signal by acquiring the backlight signal corresponding to the first optical signal. Furthermore, using all the information of the first optical signal for pre-compensation, it can achieve real-time, Fast, adaptive and accurate pre-equalization of signals.

In conjunction with the second aspect, in some implementations of the second aspect, the first digital signal is pre-compensated using the first current signal to obtain a second digital signal, and the second digital signal is subjected to digital-to-analog conversion processing to obtain the second current. The signal includes: using the first electrical signal to look up the table to obtain the first pre-compensation information, the first pre-compensation information being used to indicate the first pre-compensation coefficient; using the first pre-compensation information to perform pre-compensation processing on the first digital signal to obtain the second digital signal, and perform digital-to-analog conversion processing on the second digital signal to obtain the second current signal.

In conjunction with the second aspect, in some implementations of the second aspect, the first pre-compensation information includes an index of the first pre-compensation coefficient, or the first pre-compensation coefficient.

Combined with the second aspect, in some implementations of the second aspect, using the first electrical signal to look up the table to obtain the first pre-compensation information includes: converting the first current signal into a first voltage signal; Filtering and processing the first signal to be detected and the second signal to be detected; performing power detection on the first signal to be detected and the second signal to be detected to obtain the first detection result and the second detection result; using the first detection result and the second detection result As a result, error comparison processing is performed to obtain the first target gain; the first target gain is used to look up the table to obtain the first pre-compensation information.

Combined with the second aspect, in some implementations of the second aspect, using the first target gain to look up a table to obtain the first pre-compensation information includes: using the first target gain to obtain from the lookup table information corresponding to the first target gain The first pre-compensation information, the look-up table information includes a correspondence relationship between a plurality of target gains and a plurality of pre-compensation information, the plurality of target gains include the first target gain, and the plurality of pre-compensation information includes the first pre-compensation information.

Combined with the second aspect, in some implementations of the second aspect, the above method further includes: generating a fourth current signal, the fourth current signal is a bias current, and using the second current signal to emit a third optical signal, including: using The second current signal and the fourth current signal emit a third optical signal.

Description of drawings

FIG. 1 is a schematic structural diagram of a first light emitting device provided by an embodiment of the present application.

Figure 2 is a schematic structural diagram of a second light emitting device provided by an embodiment of the present application.

FIG. 3 is a schematic structural diagram of a first pre-compensation unit provided by an embodiment of the present application.

Figure 4 is a schematic structural diagram of a second first pre-compensation unit provided by an embodiment of the present application.

FIG. 5 is a schematic structural diagram of a third first pre-compensation unit provided by an embodiment of the present application.

FIG. 6 is a schematic diagram of a certain target gain generated by a set of compensation coefficients in an embodiment of the present application.

Figure 7 is the relationship between attenuation and temperature in different frequency bands in the embodiment of the present application.

Figure 8 is a schematic structural diagram of a second pre-compensation unit provided by an embodiment of the present application.

FIG. 9 is a schematic structural diagram of a third light emitting device provided by an embodiment of the present application.

Figure 10 is a schematic flowchart of a method for transmitting an optical signal provided by an embodiment of the present application.

Detailed ways

The technical solutions in this application will be described below with reference to the accompanying drawings.

With the evolution of passive optical network (PON) and data center communications, the signal rate is getting higher and higher. For example, the rate of the next generation passive optical network is about 50Gbps, which means that the optical network terminal (ONT) needs to have the ability to transmit 50G Baud non-return zero (NRZ) signals. The current single wave rate of data center communication is about 100Gbps, which requires the transmitter of the optical module in the data center to have the ability to transmit 50GBaud 4-level pulse amplitude modulation (PAM4) signals.

In the optical transmitter of the ONT of the current PON system, since the bandwidth is sufficient in the entire temperature range, there is no mechanism to compensate for the bandwidth. In view of the changes in the light output power and extinction ratio after the temperature rises, an automatic closed-loop control loop or an open-loop lookup table is used to maintain the stability of the light output power and extinction ratio. Among them, in terms of compensating optical power, current technology usually uses automatic power control loops. Specifically, a backlight monitoring photo detector (monitor photo detector, mPD) is provided in the emitting light component. When the laser chip emits light signals in the outgoing direction, it also emits backlight signals in the back direction at a fixed ratio. mPD converts this backlight signal into backlight current and inputs it into the automatic power control loop. A reference current is set in advance in the automatic power control loop, that is, the backlight current reference value when the output optical power is at a stable value. The photocurrent of the mPD will drive the automatic power control loop to change the bias current of the laser until the backlight current of the mPD is equal to When the error of the reference current is within a certain range, the laser output power is considered stable. Since only the absolute value of the backlight current is compared with the reference current, the bandwidth of mPD in current technology is much smaller than the bandwidth of the service signal. In terms of compensating the extinction ratio, current technology usually uses an open-loop lookup table. Specifically, the manufacturer will calibrate the extinction ratio of the transmitter before leaving the factory. In this way, when the transmitter is used, the temperature value can be obtained through the temperature monitoring circuit, and the corresponding modulation current value can be found in the lookup table, as The laser modulates the current to maintain a constant extinction ratio.

However, the above-mentioned technologies cannot meet the demand for real-time and accurate bandwidth compensation of high-speed uncooled DML at high temperatures, especially when temperature changes.

In current high-speed optical modules in data centers, there is usually a circuit with a pre-compensation function for the light emission part. For example, a continuous time linear equalizer (CTLE) with different gains stored in a register or a finite impulse response (FIR) filter bank with a small number of fixed taps. Among them, different groups of filter coefficients and high-frequency gain enhancement multiples are different. When in use, you can select a certain value in the register, that is, a fixed-gain equalizer, to supplement specific high-frequency losses.

However, in the above-mentioned technology, each time the optical transmitter is used, only a pre-compensation unit with a specific gain can be selected. Even if the coefficients are updated during use, a similar "reset" operation is required on the optical module, and real-time and adaptive compensation is not possible.

Based on this, this application proposes a device and method for transmitting optical signals, in order to accurately pre-equalize signals in real-time, quickly and adaptively.

Figure 1 shows a schematic structural diagram of a first light emitting device provided by an embodiment of the present application. As shown in Figure 1, the device 100 includes a laser 110, a photodetector 120, a service data unit 130 and a pre-compensation unit 140. Among them, the laser 110 is used to emit a first optical signal and a second optical signal. The first optical signal is the forward output optical signal of the laser 110 and is used to couple into the optical fiber to transmit the user's business data; the second optical signal is the laser 110 The optical signal output from the back is used to monitor and feedback control the quality of the signal emitted by the laser; the information carried by the second optical signal is the same as the information carried by the first optical signal. The photodetector 120 is used to perform photoelectric conversion processing on the second optical signal to obtain the first current signal. The photodetector 120 is a photodetector with a sufficient bandwidth, which can completely convert the information carried by the second optical signal through photoelectric conversion. transferred to the first current signal, so that the first current signal includes all the information carried by the second optical signal. The service data unit 130 is used to receive user service data and generate a first digital signal. The pre-compensation unit 140 is configured to use the first current signal to pre-compensate the first digital signal to obtain a second digital signal, perform digital-to-analog conversion processing on the second digital signal to obtain a second current signal, and the second current signal is a modulated current. The laser 110 is also used to emit a third optical signal using the second current signal, and the third optical signal is an optical signal emitted after pre-compensation. Wherein, the photodetector is a photodetector with sufficient bandwidth, that is, the working bandwidth of the photodetector is greater than or equal to the bandwidth required to recover the information carried by the second optical signal from the second optical signal, or the working bandwidth of the photodetector The bandwidth is greater than or equal to a certain proportion of the bandwidth of the first optical signal, such as 0.75 times, 0.8 times, etc. Optionally, the working bandwidth of the photodetector may be greater than or equal to the bandwidth required to recover the first digital signal without the need for an equalization function.

The device disclosed in this application obtains all the information of the first optical signal by acquiring the backlight signal corresponding to the first optical signal. Furthermore, it performs pre-compensation based on all the information of the first optical signal, and can achieve real-time, Fast, adaptive and accurate pre-equalization of signals.

FIG. 2 shows a schematic structural diagram of a second light-emitting device provided by an embodiment of the present application. In the device 200, except for the pre-compensation unit 140, other components are the same as the device 100. As shown in FIG. 2 , a possible structure of the pre-compensation unit 140 may include a first pre-compensation unit 141 and a second pre-compensation unit 142 . Among them, the first pre-compensation unit 141 is used to use the first electrical signal to look up the table to obtain the first pre-compensation information, and the first pre-compensation information is used to indicate the first pre-compensation coefficient; the second pre-compensation unit 142 is used to use the first pre-compensation The compensation information performs pre-compensation processing on the first digital signal to obtain a second digital signal, and performs digital-to-analog conversion processing on the second digital signal to obtain a second current signal. Wherein, the first pre-compensation information includes an index of the first pre-compensation coefficient, or the first pre-compensation coefficient. The index of the first pre-compensation coefficient is used to look up the table to obtain the first pre-compensation coefficient.

The device disclosed in this application obtains the corresponding pre-compensation coefficient according to the first pre-compensation information, pre-compensates the signal according to the pre-compensation parameter, and can accurately pre-equalize the signal in real-time, quickly and adaptively.

FIG. 3 is a schematic structural diagram of a first pre-compensation unit provided by an embodiment of the present application. In the structure shown in FIG. 3 , the first voltage signal may include signals in two frequency bands, and the corresponding first pre-compensation unit 140 may include two filters to process the signals in the two frequency bands respectively.

Specifically, a possible structure of the first pre-compensation unit 141 may include a first converter 1411, a first filter 1412, a second filter 1413, a first power detection unit 1414, a second power detection unit 1415, an error Comparison unit 1416 and processor 1417. Among them, the first converter 1411 is used to convert the first current signal into a first voltage signal; the first filter 1412 is used to filter the first voltage signal to obtain the first signal to be detected; and the second filter 1413 is used to The first voltage signal is filtered to obtain a second signal to be detected. The first filter 1412 and the second filter 1413 allow signals to pass in different frequency bands. The first power detection unit 1414 is used to perform power detection on the first signal to be detected, and obtain the first detection result; the second power detection unit 1415 is used to perform power detection on the second signal to be detected, and obtain the second detection result; error comparison The unit 1416 is configured to perform error comparison processing on the first detection result and the second detection result to obtain the first target gain; the processor 1417 is configured to use the first target gain table lookup to obtain the first pre-compensation information. Wherein, the processor may be a central processing unit CPU, a digital signal processor DSP or a micro control unit MCU.

The device disclosed in this application processes the signals in the two frequency bands of the first voltage signal converted from the first optical signal through two filters to obtain two detection results, and further obtains the final pre-compensation based on the two detection results. coefficients, which can accurately pre-equalize signals in real-time, quickly and adaptively.

Figure 4 is a schematic structural diagram of a second first pre-compensation unit provided by an embodiment of the present application. In the structure shown in FIG. 4 , the first voltage signal may include signals in three frequency bands, and the corresponding first pre-compensation unit 140 may include three filters to process the signals in the three frequency bands respectively.

Specifically, the device 400 adds a third filter 1418 and a third power detection unit 1419 based on the device 300 . The third filter 1418 is used to filter the first voltage signal to obtain a third signal to be detected, and the third power detection unit 1419 is used to perform power detection on the third signal to be detected to obtain a third detection result. The error comparison unit 1416 is used to perform error comparison processing on the first detection result, the second detection result and the third detection result to obtain the first target gain. The functions of the first converter 1411 and the processor 1417 can be referred to the description in FIG. 3 and will not be described again here.

It should be understood that through the introduction in Figures 3 and 4, those in the art can understand that the light emitting device can specifically set multiple filters according to the signals in multiple frequency bands included in the first optical signal, thereby obtaining multiple Test results. Further, error comparison processing is performed on multiple detection results to obtain the first target gain, thereby looking up the table to obtain the first pre-compensation information, and thereby obtaining the first pre-compensation coefficient. The first target gain may be one or more gains, and the first pre-compensation coefficient may also be one or more coefficients. In other words, the first target gain may be a collective name for a group of gains, and the first pre-compensation coefficient may be a collective name for a group of compensation coefficients.

The device disclosed in this application processes signals of multiple frequency bands of the first voltage signal converted from the first optical signal through multiple filters to obtain multiple detection results, and further obtains final pre-compensation based on the multiple detection results. coefficients, which can accurately pre-equalize signals in real-time, quickly and adaptively.

FIG. 5 is a schematic structural diagram of a third first pre-compensation unit provided by an embodiment of the present application. In the structure shown in Figure 5, a memory 1410 is added to the structure shown in Figure 3. The processor 1410 is pre-configured with lookup table information. The lookup table information includes the correspondence between multiple target gains and multiple pre-compensation information. The plurality of target gains include a first target gain, and the plurality of pre-compensation information include the first pre-compensation information. The processor 1417 is specifically configured to use the first target gain from the lookup table First pre-compensation information is obtained from the information, and the first pre-compensation information is used to indicate a first pre-compensation coefficient corresponding to the first target gain.

Specifically, multiple detection results are input into the processor 1410 for calculation to obtain the first target gain expected to be obtained in the high frequency band, and the processor 1410 inputs the calculation result (first target gain) into the look-up table (look-up). table, LUT) to find the lookup table parameter closest to the target gain, thereby obtaining the corresponding first pre-compensation information or first pre-compensation coefficient.

It should be understood that "the lookup table parameter closest to the target gain", "nearest" means that there is a threshold for the one-to-one correspondence between the target gain and the pre-compensation coefficient. When the error is within this threshold range, the target gain is considered to be the same as the pre-compensation coefficient. The coefficients are corresponding relationships.

It should also be understood that the first pre-compensation information may directly include the first pre-compensation coefficient, or include the first pre-compensation information including the index of the first pre-compensation coefficient. In this way, through a specific index number, the first pre-compensation coefficient can be further obtained by looking up the table. Precompensation coefficient.

Among them, a signal spectrum that meets the emission requirements (eye diagram template, extinction ratio) usually has a fixed roll-off characteristic. As an example and not a limitation, for 50G NRZ signals, the ratio of signal energy in [0~10GHz], [10~20GHz], [20~30GHz], [30~40GHz], [40~50GHz] is fixed , therefore, a lookup table can be set in advance in the electrical chip of the light-emitting device (specifically, it can be a memory). The first 5 columns of the lookup table are the energy attenuation ratios of different frequency bands normalized by the first frequency band. The target gain can be a desired compensation degree based on the first 5 columns. The sixth column has different compensations. The degree of high-frequency attenuation of the filter coefficient (can be called compensation information). For example, the lookup table can be as shown in Table 1 below, where n is a positive integer greater than 0.

Table 1 Lookup table format

The look-up table can be preset by the manufacturer into the electrical chip register of the light-emitting device before the light-emitting device leaves the factory. FIG. 6 shows a schematic diagram of a certain target gain generated by a set of compensation coefficients in an embodiment of the present application. The pre-compensated FIR filter coefficients will produce gains at high frequencies, and different filter coefficients will produce different gains at high frequencies. Therefore, this register can preset different groups of FIR filter coefficients, which are characterized by different gains produced at high frequencies. According to the size of the register, multiple groups of FIR filter coefficients can be preset, and their corresponding high-frequency gains gradually increase.

Optionally, in the embodiment of the present application, the impact of temperature on high-frequency attenuation may be further considered. Figure 7 shows the relationship between attenuation and temperature in different frequency bands in the embodiment of the present application. As shown in Figure 7, as the temperature increases, the high-frequency attenuation becomes larger. When the error comparison unit inputs the result to the MCU or CPU, the MCU or CPU calculates the size of the high-frequency attenuation and compares it with the lookup table. Compare the attenuation of the corresponding frequency band and select the FIR sequence of the corresponding pre-compensation coefficient whichever attenuation is close to it.

The device disclosed in this application can preset a lookup table to obtain the corresponding compensation coefficient according to the detection result of the first optical signal, and can perform accurate pre-equalization of the signal in real time, quickly and adaptively.

Figure 8 shows a schematic structural diagram of the second pre-compensation unit provided by the embodiment of the present application. As shown in FIG. 8 , the second pre-compensation unit 142 may include a digital-to-analog converter 1421 and a driver 1422. Among them, the digital-to-analog converter 1421 is used to perform pre-compensation processing on the first digital signal using the first pre-compensation information to obtain a second digital signal, and perform photoelectric conversion processing on the second digital signal to obtain a third current signal. The driver 1422 is used to perform pre-compensation processing on the first digital signal to obtain a third current signal. The third current signal is amplified to obtain a second current signal.

As a possible implementation, the digital-to-analog converter 1421 can pre-compensate the first digital signal by itself, the first pre-compensation information can include the index of the first pre-compensation coefficient, and the digital-to-analog converter 1421 can use the first pre-compensation The index of the coefficient is looked up in the table to obtain the first pre-compensation coefficient, thereby completing the pre-compensation of the first digital signal. In this case, the table saved by the processor 1410 may not have a specific pre-compensation coefficient, but only the corresponding relationship between the target gain and the pre-compensation information. That is to say, the processor 1410 may use the first target gain to determine the first pre-compensation. The index of the coefficient is then sent to the digital-to-analog converter 1421. The digital-to-analog converter 1421 uses the index number to look up the table to obtain the specific first pre-compensation coefficient.

As another possible implementation, although not shown in the figure, the digital-to-analog converter 1421 may further include a digital signal processor 1423. The digital signal processor 1423 is used to perform pre-compensation processing on the first digital signal using the first pre-compensation information to obtain the second digital signal. The digital-to-analog converter 1421 is specifically used to perform digital-to-analog conversion on the second digital signal to obtain the third digital signal. Three current signals. In this case, the table saved by the processor 1410 may not have a specific pre-compensation coefficient, but only the corresponding relationship between the target gain and the pre-compensation information. That is to say, the processor 1410 may use the first target gain to determine the first pre-compensation. The index of the coefficient is then sent to the digital signal processor 1423. The digital signal processor 1423 uses the index number to look up the table to obtain the specific first pre-compensation coefficient.

As another possible implementation, the second pre-compensation unit 142 may only include the driver 1422. In this case, the initiator 1422 may integrate balancing modules (or units or circuits) of various circuit configurations, and the driver 1422 may use the first pre-compensation The first pre-compensation information sent from the unit switches mode on its own to realize the function of the second pre-compensation unit 142, and uses the first pre-compensation information to complete pre-compensation of the first digital signal.

FIG. 9 is a schematic structural diagram of a third light emitting device provided by an embodiment of the present application. The device 900 includes a laser 110, a photodetector 120, a service data unit 130, a first pre-compensation unit 141 and a second pre-compensation unit 142. Wherein, the laser 110 is used to emit a first optical signal and a second optical signal. The first optical signal is the optical signal output by the laser 110 in the forward direction. The second optical signal is the optical signal output by the laser 110 in the backward direction. The second optical signal is the optical signal output by the laser 110 in the backward direction. The information carried is the same as the information carried by the first optical signal. The photodetector 120 is used to perform photoelectric conversion processing on the second optical signal to obtain the first current signal. The photodetector 120 is a photodetector with a sufficient bandwidth, which can completely convert the information carried by the second optical signal through photoelectric conversion. transferred to the first current signal, so that the first current signal includes all the information carried by the second optical signal. The service data unit 130 is used to receive user service data and generate a first digital signal. The first pre-compensation unit 141 is used to look up the table using the first electrical signal to obtain the first pre-compensation information, and the first pre-compensation information is used to indicate the first pre-compensation coefficient. The second pre-compensation unit 142 is configured to use the first pre-compensation information to perform pre-compensation processing on the first digital signal to obtain a second digital signal, and perform digital-to-analog conversion processing on the second digital signal to obtain a second current signal. Laser 110 is also configured to emit a third optical signal using the second current signal. Wherein, the photodetector is a photodetector with sufficient bandwidth, that is, the working bandwidth of the photodetector is greater than or equal to the bandwidth required to recover the information carried by the second optical signal from the second optical signal, or the working bandwidth of the photodetector The bandwidth is greater than or equal to a certain proportion of the bandwidth of the first optical signal, such as 0.75 times.

Wherein, the first pre-compensation unit includes a first converter 1411, a first filter 1412, a second filter 1413, The third filter 1418, the first power detection unit 1414, the second power detection unit 1415, the third power detection unit 1419, the error comparison unit 1416, the processor 1417 and the memory 1410. The first converter 1411 is used to convert the first current signal into a first voltage signal. The first filter 1412 is used to filter the first voltage signal to obtain a first signal to be detected. The second filter 1413 is used to filter the first voltage signal to obtain a second signal to be detected. The third filter 1418 is used to filter the first voltage signal to obtain a third signal to be detected. The first filter 1412, the second filter 1413, and the third filter 1418 allow signals to pass through different frequency bands. The first power detection unit 1414 is used to perform power detection on the first signal to be detected to obtain a first detection result. The second power detection unit 1415 is used to perform power detection on the second signal to be detected to obtain a second detection result. The third power detection unit 1419 is used to perform power detection on the third signal to be detected to obtain a third detection result. The error comparison unit 1416 is used to perform error comparison on the first detection result, the second detection result and the third detection result to obtain the first target gain. The processor 1417 is configured to obtain the first pre-compensation coefficient from the memory 1410 for the first target gain. Wherein, the processor may be a central processing unit CPU, a digital signal processor DSP or a micro control unit MCU.

It should be understood that the above-mentioned light emitting device can specifically set multiple filters (including but not limited to two filters) according to the signals of multiple frequency bands (including but not limited to two frequency bands or three frequency bands) included in the first optical signal. or three filters) to obtain multiple detection results. Further error comparison is performed on multiple detection results to obtain the first target gain, thereby obtaining the first pre-compensation coefficient. The first target gain may be one or more gains, and the first pre-compensation coefficient may also be one or more coefficients. In other words, the first target gain may be a collective name for a group of gains, and the first pre-compensation coefficient may be a collective name for a group of compensation coefficients.

Among them, the second pre-compensation unit 142 includes a digital-to-analog converter 1421 and a driver 1422. Among them, the digital-to-analog converter 1421 is used to perform pre-compensation processing on the first digital signal using the first pre-compensation information to obtain a second digital signal, and perform photoelectric conversion processing on the second digital signal to obtain a third current signal. The driver 1422 is used to perform pre-compensation processing on the first digital signal to obtain a third current signal. The third current signal is amplified to obtain a second current signal. In addition, the driver 1422 is also used to generate a fourth current signal, and the fourth current signal is a bias current,

Optionally, the first pre-compensation unit 141 and the second pre-compensation unit 142 may also be collectively referred to as the pre-compensation unit 140. The pre-compensation unit 140 is configured to use the first current signal to pre-compensate the first digital signal to obtain a second digital signal, and perform digital-to-analog conversion processing on the second digital signal to obtain a second current signal.

The laser 110 is specifically configured to emit a third optical signal using the second current signal and the fourth current signal.

Figure 10 is a schematic flowchart of a method for transmitting an optical signal provided by an embodiment of the present application. The method 1000 may be performed by the above-mentioned light-emitting device (eg, the light-emitting device 100, the light-emitting device 900, etc.).

S1010. Emit a first optical signal and a second optical signal. The first optical signal is the optical signal output by the laser in the forward direction. The second optical signal is the optical signal output by the laser in the backward direction. The information carried by the second optical signal is the same as the first optical signal. Light signals carry the same information.

S1020, perform photoelectric conversion processing on the second optical signal to obtain the first current signal.

The first circuit signal includes all information carried by the second optical signal.

S1030: Receive user service data and generate a first digital signal.

Wherein, the photodetector is a photodetector with sufficient bandwidth, that is, the working bandwidth of the photodetector is greater than or equal to the bandwidth required to recover the first digital signal, or the working bandwidth of the photodetector is greater than or equal to the bandwidth of the first optical signal. A certain ratio value, such as 0.75 times.

S1040: Use the first current signal to perform pre-compensation processing on the first digital signal to obtain a second digital signal, and perform digital-to-analog conversion processing on the second digital signal to obtain a second current signal.

Specifically, the first electrical signal is used to look up the table to obtain the first pre-compensation information, and the first pre-compensation information is used to indicate the first pre-compensation coefficient; the first pre-compensation information is used to pre-compensate the first digital signal to obtain the second digital signal. signal, and performs digital-to-analog conversion processing on the second digital signal to obtain a second current signal.

Wherein, the first pre-compensation information includes an index of the first pre-compensation coefficient, or the first pre-compensation coefficient. The index of the first pre-compensation coefficient is used to look up the table to obtain the first pre-compensation coefficient.

Optionally, using the first electrical signal to obtain the first pre-compensation information includes: using the first electrical signal to look up a table to obtain the first pre-compensation information, including: converting the first current signal into a first voltage signal; The signal is filtered to process the first signal to be detected and the second signal to be detected; power detection is performed on the first signal to be detected and the second signal to be detected to obtain the first detection result and the second detection result; using the first detection result and the second signal to be detected The two detection results are subjected to error comparison processing to obtain the first target gain; the first target gain is used to look up the table to obtain the first pre-compensation information.

Optionally, using the first target gain to look up the table to obtain the first pre-compensation information includes: using the first target gain to obtain the first pre-compensation information corresponding to the first target gain from the look-up table information, where the look-up table information includes a plurality of Correspondence relationship between a target gain and a plurality of pre-compensation information, the plurality of target gains include a first target gain, the plurality of pre-compensation information includes the first pre-compensation information, the first pre-compensation information is used to indicate corresponding to the first target gain The first pre-compensation coefficient.

S1050 uses the second current signal to transmit a third optical signal.

Optionally, the light emitting device can also generate a fourth current signal, and the fourth current signal is a bias current. Wherein, using the second current signal to transmit the third optical signal includes: using the second current signal and the fourth current signal to transmit the third optical signal, and the third optical signal is an optical signal emitted after pre-compensation.

The method disclosed in this application obtains all the information of the first optical signal by acquiring the backlight signal corresponding to the first optical signal. Furthermore, pre-compensation is performed based on all the information of the first optical signal, which enables real-time, Fast, adaptive and accurate pre-equalization of signals.

An embodiment of the present application also provides a device, including a processor and an interface.

It should be understood that the above processing device may be a chip. For example, the processing device may be a field programmable gate array (FPGA), an application specific integrated circuit (ASIC), or a system on chip (SoC), or It can be a central processing unit (CPU), a network processor (NP), a digital signal processing circuit (DSP), or a microcontroller unit , MCU), it can also be a programmable logic device (PLD) or other integrated chip.

During the implementation process, the signal processing flow of the access point provided by this application can be completed through the integrated logic circuit of the hardware in the processor or instructions in the form of software. The steps disclosed in conjunction with the embodiments of the present application can be directly implemented by a hardware processor, or executed by a combination of hardware and software modules in the processor. The software module can be located in random access memory, flash memory, read-only memory, programmable read-only memory or electrically erasable programmable memory, registers and other mature storage media in this field. The storage medium is located in the memory, and the processor reads the information in the memory and combines Its hardware completes the steps of the above method. To avoid repetition, it will not be described in detail here.

It should be noted that the processor in the embodiment of the present application may be an integrated circuit chip with signal processing capabilities. During the implementation process, each step of the above method embodiment can be completed through an integrated logic circuit of hardware in the processor or instructions in the form of software. The above-mentioned processor may be a general-purpose processor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field programmable gate array (FPGA) or other programmable logic devices, discrete gate or transistor logic devices, or discrete hardware components. . Each method, step and logical block diagram disclosed in the embodiment of this application can be implemented or executed. A general-purpose processor may be a microprocessor or the processor may be any conventional processor, etc. The steps of the method disclosed in conjunction with the embodiments of the present application can be directly implemented by a hardware decoding processor, or executed by a combination of hardware and software modules in the decoding processor. The software module can be located in random access memory, flash memory, read-only memory, programmable read-only memory or electrically erasable programmable memory, registers and other mature storage media in this field. The storage medium is located in the memory, and the processor reads the information in the memory and completes the steps of the above method in combination with its hardware.

It can be understood that the memory in the embodiment of the present application may be a volatile memory or a non-volatile memory, or may include both volatile and non-volatile memories. Among them, non-volatile memory can be read-only memory (ROM), programmable ROM (PROM), erasable programmable read-only memory (erasable PROM, EPROM), electrically removable memory. Erase electrically programmable read-only memory (EPROM, EEPROM) or flash memory. Volatile memory can be random access memory (RAM), which is used as an external cache. By way of illustration, but not limitation, many forms of RAM are available, such as static random access memory (SRAM), dynamic random access memory (DRAM), synchronous dynamic random access memory (synchronous DRAM, SDRAM), double data rate synchronous dynamic random access memory (double data rate SDRAM, DDR SDRAM), enhanced synchronous dynamic random access memory (enhanced SDRAM, ESDRAM), synchronous link dynamic random access memory (synchlink DRAM, SLDRAM) ) and direct memory bus random access memory (direct rambus RAM, DR RAM). It should be noted that the memory of the systems and methods described herein is intended to include, but is not limited to, these and any other suitable types of memory.

According to the method provided by the embodiment of the present application, the present application also provides a computer program product. The computer program product includes: computer program code. When the computer program code is run on a computer, it causes the computer to execute the embodiment shown in Figure 10 method in.

According to the method provided by the embodiment of the present application, the present application also provides a computer-readable medium. The computer-readable medium stores program code. When the program code is run on a computer, it causes the computer to execute the method of the embodiment of Figure 10 .

In the above embodiments, it may be implemented in whole or in part by software, hardware, firmware, or any combination thereof. When implemented using software, it may be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer instructions. When the computer instructions are loaded and executed on the computer, the processes or functions described in the embodiments of the present application are generated in whole or in part. The computer may be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions may be stored in or transmitted from one computer-readable storage medium to another, e.g., the computer instructions may be transferred from a website, computer, server, or data center Transmission to another website, computer, server or data center through wired (such as coaxial cable, optical fiber, digital subscriber line (DSL)) or wireless (such as infrared, wireless, microwave, etc.) means. The computer-readable storage medium may be a computer Any available media that can be accessed by the machine or a data storage device such as a server or data center integrated with one or more available media. The usable media may be magnetic media (eg, floppy disks, hard disks, tapes), optical media (eg, high-density digital video discs (DVD)), or semiconductor media (eg, solid state discs, SSD)) etc.

The terms "component", "module", "system", etc. used in this specification are used to refer to computer-related entities, hardware, firmware, a combination of hardware and software, software, or software in execution. For example, a component may be, but is not limited to, a process, a processor, an object, an executable file, a thread of execution, a program and/or a computer running on a processor. Through the illustrations, both applications running on the computing device and the computing device may be components. One or more components can reside in a process and/or thread of execution and a component can be localized on one computer and/or distributed between two or more computers. Additionally, these components can execute from various computer-readable media having various data structures stored thereon. A component may, for example, be based on a signal having one or more data packets (eg, data from two components interacting with another component, a local system, a distributed system, and/or a network, such as the Internet, which interacts with other systems via signals) Communicate through local and/or remote processes.

Those of ordinary skill in the art will appreciate that the various illustrative logical blocks and steps described in connection with the embodiments disclosed herein can be implemented as electronic hardware, or a combination of computer software and electronic hardware. accomplish. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Skilled artisans may implement the described functionality using different methods for each specific application, but such implementations should not be considered beyond the scope of this application.

Those skilled in the art can clearly understand that for the convenience and simplicity of description, the specific working processes of the systems, devices and units described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be described again here.

In the several embodiments provided in this application, it should be understood that the disclosed systems, devices and methods can be implemented in other ways. For example, the device embodiments described above are only illustrative. For example, the division of the units is only a logical function division. In actual implementation, there may be other division methods. For example, multiple units or components may be combined or can be integrated into another system, or some features can be ignored, or not implemented. On the other hand, the coupling or direct coupling or communication connection between each other shown or discussed may be through some interfaces, and the indirect coupling or communication connection of the devices or units may be in electrical, mechanical or other forms.

The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place, or they may be distributed to multiple network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of this embodiment.

In addition, each functional unit in each embodiment of the present application can be integrated into one processing unit, each unit can exist physically alone, or two or more units can be integrated into one unit.

In the above embodiments, the functions of each functional unit may be implemented in whole or in part by software, hardware, firmware, or any combination thereof. When implemented using software, it may be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer instructions (programs). When the computer program instructions (program) are loaded and executed on a computer, the processes or functions described in the embodiments of the present application are generated in whole or in part. The computer may be a general purpose computer, a special purpose computer, a computer network, or other programmable device. The computer instructions may be stored in or transmitted from one computer-readable storage medium to another, for example, the computer instructions may be transferred from a website, computer, server or data The center transmits to another website site, computer, server or data center through wired (such as coaxial cable, optical fiber, digital subscriber line (DSL)) or wireless (such as infrared, wireless, microwave, etc.) means. The computer-readable storage medium may be any available medium that can be accessed by a computer or a data storage device such as a server, data center, etc. that contains one or more available media integrated. The available media may be magnetic media (eg, floppy disk, hard disk, magnetic tape), optical media (eg, DVD), or semiconductor media (eg, solid state disk (SSD)), etc.

If the functions are implemented in the form of software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application is essentially or the part that contributes to the existing technology or the part of the technical solution can be embodied in the form of a software product. The computer software product is stored in a storage medium, including Several instructions are used to cause a computer device (which may be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the methods described in various embodiments of this application. The aforementioned storage media include: U disk, mobile hard disk, read-only memory (ROM), random access memory (RAM), magnetic disk or optical disk and other media that can store program code. .

The above are only specific embodiments of the present application, but the protection scope of the present application is not limited thereto. Any person familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed in the present application. should be covered by the protection scope of this application. Therefore, the protection scope of this application should be subject to the protection scope of the claims.

Claims

A light emitting device, characterized by including a laser, a photoelectric detector, a service data unit and a pre-compensation unit, wherein:

The laser is used to emit a first optical signal and a second optical signal. The first optical signal is the optical signal outputted forward by the laser, and the second optical signal is the optical signal outputted backward by the laser. , the information carried by the second optical signal is the same as the information carried by the first optical signal;

The photodetector is used to perform photoelectric conversion processing on the second optical signal to obtain a first current signal;

The service data unit is used to receive user service data and generate a first digital signal;

The pre-compensation unit is configured to use the first current signal to pre-compensate the first digital signal to obtain a second digital signal, and perform digital-to-analog conversion processing on the second digital signal to obtain a second current signal;

The laser is also used to emit a third optical signal using the second current signal.
The device according to claim 1, wherein the working bandwidth of the photodetector is greater than or equal to the bandwidth required to recover the information carried by the second optical signal from the second optical signal.
The device according to claim 2, characterized in that the pre-compensation unit includes a first pre-compensation unit and a second pre-compensation unit, wherein:

The first pre-compensation unit is used to use the first current signal to look up a table to obtain first pre-compensation information, where the first pre-compensation information is used to indicate a first pre-compensation coefficient;

The second pre-compensation unit is configured to perform pre-compensation processing on the first digital signal using the first pre-compensation information to obtain the second digital signal, and perform digital-to-analog conversion processing on the second digital signal to obtain the second digital signal. the second current signal.
The device according to claim 3, wherein the first pre-compensation information includes an index of the first pre-compensation coefficient, or the first pre-compensation coefficient.
The device according to claim 3 or 4, characterized in that the first pre-compensation unit includes a first converter, a first filter, a second filter, a first power detection unit, a second power detection unit, The error comparison unit and processor, the first filter and the second filter allow signals to pass in different frequency bands, wherein:

The first converter is used to convert the first current signal into a first voltage signal;

The first filter is used to filter the first voltage signal to obtain a first signal to be detected;

The second filter is used to filter the first voltage signal to obtain a second signal to be detected;

The first power detection unit is used to perform power detection on the first signal to be detected to obtain a first detection result;

The second power detection unit is used to perform power detection on the second signal to be detected to obtain a second detection result;

The error comparison unit is used to perform error comparison processing on the first detection result and the second detection result to obtain a first target gain;

The processor is configured to use the first target gain to look up the table to obtain the first pre-compensation information.
The device according to claim 5, characterized in that the first pre-compensation unit further includes a memory, the memory is pre-configured with look-up table information, the look-up table information includes a plurality of target gains and a plurality of pre-compensation information. corresponding relationship, the plurality of target gains include a first target gain, and the plurality of pre-compensation information includes the first pre-compensation compensation information,

The processor is specifically configured to use the first target gain to obtain the first pre-compensation information from the look-up table information, where the first pre-compensation information is used to indicate that the first pre-compensation information corresponds to the first target gain. of the first pre-compensation coefficient.
The device according to any one of claims 4 to 6, characterized in that the processor includes a central processing unit (CPU), a digital signal processor (DSP) or a micro control unit (MCU).
The device according to claim 3, characterized in that the second pre-compensation unit includes a digital-to-analog converter and a driver, wherein:

The digital-to-analog converter is configured to use the first pre-compensation information to perform pre-compensation processing on the first digital signal to obtain the second digital signal, and perform photoelectric conversion processing on the second digital signal to obtain a third current signal;

The driver is used to amplify the third current signal to obtain the second current signal.
The device according to claim 8, wherein the digital-to-analog converter includes a digital signal processor (DSP),

The DSP is used to perform pre-compensation processing on the first digital signal using the first pre-compensation information to obtain a second digital signal,

The digital-to-analog converter is specifically configured to perform photoelectric conversion processing on the second digital signal to obtain the third current signal.
The device according to claim 9, wherein the driver is further used to generate a fourth current signal, and the fourth current signal is a bias current,

The laser is specifically configured to emit the third optical signal using the second current signal and the fourth current signal.
A method for transmitting optical signals, characterized by including:

Emit a first optical signal and a second optical signal. The first optical signal is the optical signal outputted forward by the laser. The second optical signal is the optical signal outputted backward by the laser. The second optical signal is The information carried is the same as the information carried by the first optical signal;

Perform photoelectric conversion processing on the second optical signal to obtain a first current signal;

Receive user service data and generate a first digital signal;

Use the first current signal to perform pre-compensation processing on the first digital signal to obtain a second digital signal, and perform digital-to-analog conversion processing on the second digital signal to obtain a second current signal;

A third optical signal is emitted using the second current signal.
The method according to claim 11, characterized in that: using the first current signal to perform pre-compensation processing on the first digital signal to obtain a second digital signal, and performing digital-to-analog conversion on the second digital signal Processing to obtain the second current signal includes:

Use the first electrical signal to look up a table to obtain first pre-compensation information, where the first pre-compensation information is used to indicate a first pre-compensation coefficient;

Use the first pre-compensation information to perform pre-compensation processing on the first digital signal to obtain the second digital signal, and perform digital-to-analog conversion processing on the second digital signal to obtain the second current signal.
The method of claim 12, wherein the first pre-compensation information includes an index of the first pre-compensation coefficient, or the first pre-compensation coefficient.
The method according to claim 12 or 13, characterized in that said using the first electrical signal to look up the table to obtain the first pre-compensation information includes:

convert the first current signal into a first voltage signal;

Perform filtering processing on the first voltage signal to obtain a first signal to be detected and a second signal to be detected;

Perform power detection on the first signal to be detected and the second signal to be detected to obtain a first detection result and a second detection result;

Use the first detection result and the second detection result to perform error comparison processing to obtain a first target gain;

The first pre-compensation information is obtained using the first target gain lookup table.
The method according to claim 14, wherein said using the first target gain to look up the table to obtain the first pre-compensation information includes:

The first pre-compensation information corresponding to the first target gain is obtained from look-up table information using the first target gain. The look-up table information includes correspondences between multiple target gains and multiple pre-compensation information. , the plurality of target gains include a first target gain, and the plurality of pre-compensation information include the first pre-compensation information.
The method according to claim 11, characterized in that, the method further includes:

Generating a fourth current signal, the fourth current signal being a bias current,

Using the second current signal to emit a third optical signal includes:

The third optical signal is emitted using the second current signal and the fourth current signal.