CN116418400A

CN116418400A - Control method, device, chip, optical line terminal and passive optical network

Info

Publication number: CN116418400A
Application number: CN202111640147.3A
Authority: CN
Inventors: 吴逸文; 卢彦兆
Original assignee: Huawei Technologies Co Ltd
Current assignee: Huawei Technologies Co Ltd
Priority date: 2021-12-29
Filing date: 2021-12-29
Publication date: 2023-07-11
Also published as: WO2023125509A1

Abstract

The application discloses a control method, a device, a chip, an optical line terminal and a passive optical network, wherein a first optical network unit and a second optical network unit are two adjacent optical network units, so that a power difference value can be obtained by making a difference between burst receiving power of the first optical network unit and burst receiving power of the second optical network unit, a first bias voltage adjustment value of a photodiode is calculated by using the power difference value, before a first uplink burst time slot is carried out after a second uplink burst time slot, the bias voltage of the photodiode is adjusted by using the first bias voltage adjustment value, the bias voltage of the photodiode is reduced when the power difference value is larger than zero, or the bias voltage of the photodiode is increased when the power difference value is smaller than zero, the photoelectric conversion gain of the photodiode is larger, the detection current corresponding to the generated second optical network unit is reduced to be closer to the detection current corresponding to the first optical network unit, so that the sampling threshold change range connected with the photodiode is reduced, and the burst establishment time is shortened.

Description

Control method, device, chip, optical line terminal and passive optical network

Technical Field

The present disclosure relates to the field of optical communications technologies, and in particular, to a control method, a device, a chip, an optical line terminal, and a passive optical network.

Background

The passive optical network (passive optical network, PON) technology is one of the most widely used access technologies from optical fiber to the home, and referring to fig. 1, a schematic structural diagram of a passive optical network system is shown, where an optical distribution network (optical distribution network, ODN) is disposed between an optical line terminal (optical line termination, OLT) 1 and an optical network unit (optical network unit, ONU) 3. The optical distribution network may include an optical splitter 2, a trunk optical fiber, and branch optical fibers, where the OLT 1 and the optical splitter 2 are connected by the trunk optical fiber, the optical splitter 2 implements point-to-multipoint optical power distribution, and the optical splitter 2 is connected to a plurality of ONUs 3 through a plurality of branch optical fibers. In the passive optical network, the OLT 1 is configured to connect to a service provider local core network, and the ONU 3 is configured to connect to a user equipment (user) 4.

The direction from the OLT to the ONUs is referred to as the downstream direction, and the direction from the ONUs to the OLT is referred to as the upstream direction. In practical application, the core of the physical layer optical fiber transmission of the passive optical network is uplink optical burst mode transmission and downlink broadcast transmission. In a passive optical network, an OLT is typically connected to a plurality of ONUs, and it is necessary to transmit and receive an upstream signal in a time division multiplexing (time division multiplex, TDM) manner. For example, the ONU at the user end transmits an optical burst signal to the OLT in an optical burst mode, after receiving an upstream optical burst signal, an optical receiving component (receiver optical subassembly, ROSA) in the OLT converts the optical burst signal into an electrical signal to obtain a detection current, where the ROSA includes a photodiode and a transimpedance amplifier (trans-impedance amplifier, TIA), and the optical burst signal has a received optical power (received optical power, ROP) and may also be referred to as a burst received power. The TIA needs to be charged and discharged rapidly to establish sampling thresholds corresponding to different received optical powers, so as to accurately sample signals of different received optical powers.

Currently, after receiving an optical burst signal, the OLT needs a certain reception preparation time to perform TIA charge and discharge, so that a sampling threshold of the TIA is matched with the received optical power of the next optical burst signal, so that the next optical burst signal is accurately received, and the reception preparation time of the OLT is called burst setup time. Because the charging and discharging speed of TIA is limited by hardware, burst setup time is generally longer, and when the burst receiving power difference between two adjacent optical burst signals is larger, the required burst setup time will be longer, so that the transmission efficiency in PON transmission network is lower.

Disclosure of Invention

In view of this, the present application provides a control method, device, chip, optical line terminal and passive optical network, which reduces burst setup time and improves transmission efficiency.

In order to solve the technical problems, the application adopts the following technical scheme:

the first aspect of the present embodiment provides a control method, where a first optical network unit and a second optical network unit are two adjacent optical network units, the first optical network unit is configured to send a first optical burst signal in a first uplink burst slot, the second optical network unit is configured to send a second optical burst signal in a second uplink burst slot, the first uplink burst slot is adjacent to the second uplink burst slot, and the first uplink burst slot is located behind the second uplink burst slot, so that a difference between a burst receiving power of the first optical network unit and a burst receiving power of the second optical network unit can be calculated by a difference method, a first bias adjustment value of a photodiode is calculated by using the difference between the power, the photodiode is configured to perform photoelectric conversion on the first optical burst signal and the second optical burst signal, and before the first uplink burst slot is located behind the second uplink burst slot, the bias of the photodiode is adjusted by using the first bias adjustment value, so that the bias of the photodiode is reduced when the difference is greater than zero, or the bias of the photodiode when the difference is less than zero.

That is, in this embodiment of the present application, for the second optical network unit with burst receiving power larger than the first optical network unit, the bias voltage of the photodiode may be set smaller, so that the photoelectric conversion gain of the photodiode is smaller, the generated detection current corresponding to the second optical network unit is reduced to be closer to the detection current corresponding to the first optical network unit, so that the sampling threshold variation range of the TIA connected to the photodiode is reduced, the burst setup time is reduced, and for the second optical network unit with burst receiving power smaller than the first optical network unit, the bias voltage of the photodiode may be set larger, so that the photoelectric conversion gain of the photodiode is larger, the generated detection current corresponding to the second optical network unit is improved to be closer to the detection current corresponding to the first optical network unit, and the sampling threshold variation range of the TIA connected to the photodiode is reduced, so that the burst setup time is reduced. Therefore, lower cost and flexible design can be realized, and the dynamic range of the burst receiving power of the system is increased without reducing the net rate of the system.

In some possible embodiments, the absolute value of the power difference and the absolute value of the first bias voltage adjustment value are positively correlated.

In this embodiment of the present application, the absolute value of the power difference value is positively correlated with the absolute value of the first bias adjustment value, so that the larger the absolute value of the power difference value is, the larger the absolute value of the first bias adjustment value is, which is favorable for making the detection current corresponding to the second optical network unit approach to the detection current corresponding to the first optical network unit, and is favorable for reducing the burst setup time.

In some possible implementations, the first bias adjustment value is a product of a first adjustment coefficient and the power difference value, the first adjustment coefficient being a constant.

In this embodiment of the present application, the first bias adjustment value may be a product of the first adjustment coefficient and the power difference value, so that the first bias adjustment value is determined according to the power difference value, and the first bias adjustment value is proportional to the power difference value, and the obtained first bias adjustment value is relatively reasonable, which is favorable for reducing burst setup time.

In some possible embodiments, the method further comprises:

acquiring a plurality of detection currents after photoelectric conversion of the photodiodes on a plurality of optical burst signals respectively; the optical burst signal comprises the first optical burst signal or the second optical burst signal;

and respectively processing the detection currents to obtain a plurality of recovery signals, wherein the recovery signals respectively comprise service signals carried by the optical burst signals.

In the embodiment of the application, the detection current after photoelectric conversion of the photodiode can be recovered to obtain the service signal carried in the detection current, so that smooth communication is realized.

In some possible embodiments, the method further comprises:

periodically monitoring the recovery signal to obtain a performance fluctuation value between the transmission performance parameter of the first period and the transmission performance parameter of the second period; the first period and the second period are two adjacent periods, and the first period is before the second period;

calculating a second bias adjustment value of the photodiode according to the performance fluctuation value;

and after the second period is finished, the bias voltage of the photodiode is adjusted by using the second bias voltage adjustment value so as to reduce the performance fluctuation value of a third period after the second period.

In the embodiment of the application, the performance fluctuation value can be obtained according to the recovery signal, so that the second bias adjustment value is obtained by utilizing the performance fluctuation value, and then the bias voltage of the photodiode is adjusted by utilizing the second bias adjustment value, so that the bias voltage of the photodiode is finely adjusted, the transmission performance of the system can be integrally optimized by a performance monitoring feedback adjustment mechanism, the tolerance of the influence on the system performance caused by environmental fluctuation is higher, and the gain adjustment granularity low adjustment scheme is more flexible.

In some possible embodiments, the transmission performance parameter includes at least one of a signal-to-noise ratio, a bit error rate, and an error vector magnitude.

In the embodiment of the application, the transmission performance parameters can be multiple, so that the transmission performance is comprehensively reflected by the performance fluctuation value, the second bias voltage adjustment value obtained according to the performance fluctuation value is more targeted, and the transmission performance of the system is integrally optimized.

In some possible implementations, the second bias adjustment value is a product of a second adjustment coefficient and the performance fluctuation value, the second adjustment coefficient being a constant.

In this embodiment of the present application, the second bias adjustment value may be a product of the second adjustment coefficient and the performance fluctuation value, so that the second bias adjustment value is determined according to the performance fluctuation value, and the second bias adjustment value is proportional to the performance fluctuation value, where the obtained second bias adjustment value is more reasonable, and is favorable for reducing burst setup time.

In some possible embodiments, the adjusting the bias voltage of the photodiode using the first bias adjustment value includes:

transmitting the digital quantity of the first bias voltage adjustment value to a digital-to-analog converter so as to obtain a first analog voltage corresponding to the first bias voltage adjustment value by using the digital-to-analog converter, and loading the first analog voltage into a power supply circuit of the photodiode;

The adjusting the bias voltage of the photodiode using the second bias voltage adjustment value includes:

and sending the digital quantity of the second bias voltage adjustment value to the digital-to-analog converter so as to obtain a second analog voltage corresponding to the second bias voltage adjustment value by using the digital-to-analog converter, and loading the second analog voltage into a power supply circuit of the photodiode.

In the embodiment of the application, the bias voltage of the photodiode is adjusted by using the first bias voltage adjustment value and the second bias voltage adjustment value, and the bias voltage of the photodiode can be conveniently and accurately adjusted by using the digital-to-analog converter.

In some possible implementations, the digital amount of the first bias adjustment value and the digital amount of the second bias adjustment value are sent to the digital-to-analog converter via a serial peripheral interface, SPI, protocol or an internal integrated circuit, I2C, protocol.

In this embodiment of the present application, the SPI protocol or the I2C protocol may be used to send the digital value of the first bias adjustment value and the digital value of the second bias adjustment value, which is beneficial to accurate transmission of the data amount.

In some possible embodiments, before calculating the power difference, the method further comprises:

and acquiring the burst receiving power of the first optical network unit and the burst receiving power of the second optical network unit from a medium access control module.

In this embodiment of the present application, the burst receiving power of the first optical network unit and the burst receiving power of the second optical network unit may be obtained from the medium access control module, so that a bias voltage of a suitable photodiode is set in advance for a second optical burst signal of the second optical network unit, which is beneficial to reducing burst setup time.

In some possible embodiments, the first uplink burst slot and the second uplink burst slot belong to a first burst reception period;

the burst receiving power of the first optical network unit is determined according to the burst receiving power of the first optical network unit in a second burst receiving period; the burst receiving power of the second optical network unit is determined according to the burst receiving power of the second optical network unit in the second burst receiving period; the second burst reception period is a burst reception period adjacent to the first burst reception period, and the first burst reception period is located after the second burst reception period.

In the embodiment of the application, the burst receiving power of the second optical network and the second optical network unit in the subsequent burst receiving period can be determined according to the burst receiving power of the first optical network unit and the second optical network unit in the previous burst receiving period, and the obtained burst receiving power is accurate and timely, so that the burst establishing time can be reduced in a targeted manner.

In some possible embodiments, the burst received power of the first optical network unit in the second burst period is determined according to a first detection current of the first optical network unit in the second burst period; the first detection current is obtained by photoelectric conversion of a third burst signal sent by the first optical network unit in a second burst period by the photodiode;

the burst receiving power of the second optical network in a second burst period is determined according to a second detection current of the second optical network unit in the second burst period; and the second detection is obtained by photoelectric conversion of a fourth burst signal sent by the second optical network unit in the second burst period by the photodiode.

According to the embodiment of the application, the burst receiving power of the optical network unit can be calculated according to the current output by the photodiode, so that the calculated value of the burst receiving power of the optical network unit is more accurate, and the burst establishing time is reduced in a targeted manner.

In some possible embodiments, the method further comprises:

and after the bias voltage of the photodiode is adjusted, obtaining the mapping relation between the burst receiving power of the burst signal subjected to photoelectric conversion by the photodiode and the detection current, wherein the mapping relation is used for determining the burst receiving power of the burst signal according to the detection current.

In this embodiment of the present application, after the bias voltage of the photodiode is adjusted, the photoelectric conversion gain of the photodiode is correspondingly changed, and then the mapping relationship between the burst receiving power of the burst signal and the detection current is also changed, so that the mapping relationship between the burst receiving power and the detection current can be updated, so that the burst receiving power of the optical network unit in the burst period can be obtained according to the detection current of the burst receiving period in the next burst receiving period.

In some possible embodiments, the photodiode is an avalanche diode.

In the embodiment of the application, the photodiode can be an avalanche diode, the avalanche diode has larger photoelectric conversion efficiency, relatively larger detection current can be obtained, and the loss of burst signals is reduced.

A second aspect of the embodiments of the present application provides a control device, including:

the power difference calculation unit is used for performing difference operation on the burst receiving power of the first optical network unit and the burst receiving power of the second optical network unit to obtain a power difference; the first optical network unit is configured to send a first optical burst signal in a first uplink burst slot, the second optical network unit sends a second optical burst signal in a second uplink burst slot, the first uplink burst slot is adjacent to the second uplink burst slot, and the first uplink burst slot is located after the second uplink burst slot;

The bias voltage adjustment value calculation unit is used for calculating a first bias voltage adjustment value of a photodiode by utilizing the power difference value, and the photodiode is used for carrying out photoelectric conversion on the first optical burst signal and the second optical burst signal;

and the adjusting unit is used for adjusting the bias voltage of the photodiode by using the first bias voltage adjusting value before the first uplink burst time slot after the second uplink burst time slot, so that the bias voltage of the photodiode is reduced when the power difference value is larger than zero, or the bias voltage of the photodiode is increased when the power difference value is smaller than zero.

In some possible embodiments, the apparatus further comprises:

a signal processing unit, configured to obtain a plurality of detection currents after photoelectric conversion of a plurality of optical burst signals by the photodiode, where the optical burst signals include the first optical burst signal or the second optical burst signal; and respectively processing the detection currents to obtain a plurality of recovery signals, wherein the recovery signals respectively comprise service signals carried by the optical burst signals.

In some possible embodiments, the apparatus further comprises:

the performance monitoring module is used for periodically monitoring the recovery signal to acquire a performance fluctuation value between the transmission performance parameter of the first period and the transmission performance parameter of the second period; the first period and the second period are two adjacent periods, and the first period is before the second period;

the bias adjustment value calculating unit is further used for calculating a second bias adjustment value of the photodiode according to the performance fluctuation value;

the adjusting unit is further configured to adjust the bias voltage of the photodiode by using the second bias voltage adjusting value after the second period ends, so as to reduce a performance fluctuation value of a third period after the second period.

In some possible embodiments, the apparatus further comprises:

and the power acquisition module is used for acquiring the burst receiving power of the first optical network unit and the burst receiving power of the second optical network unit from the media access control module before calculating the power difference value.

In some possible embodiments, the apparatus further comprises:

and the mapping relation acquisition unit is used for acquiring the mapping relation between the burst receiving power of the burst signal subjected to photoelectric conversion by the photodiode and the detection current after the bias voltage of the photodiode is adjusted, and the mapping relation is used for determining the burst receiving power of the burst signal according to the detection current.

In some possible embodiments, the photodiode is an avalanche diode.

A third aspect of the embodiments of the present application provides a control chip, configured to execute the control method described in the first aspect of the embodiments of the present application.

In some possible embodiments, the control chip is an optical communication digital signal processing chip.

A fourth aspect of the present embodiment provides an optical line terminal, including a control chip according to the third aspect of the present embodiment.

In some possible embodiments, further comprising a photodiode and a transimpedance amplifier; the photodiode is used for carrying out photoelectric conversion on the burst signal to obtain detection current, and the transimpedance amplifier is used for amplifying the detection current output by the photodiode.

A fifth aspect of an embodiment of the present application provides a passive optical network, including:

A first optical network unit and a second optical network unit;

an optical line terminal according to a fourth aspect of the embodiments of the present application; the optical line terminal is respectively connected with the first optical network unit and the second optical network unit.

From the above technical solutions, the embodiments of the present application have the following advantages:

the embodiment of the application provides a control method, a device, a chip, an optical line terminal and a passive optical network, wherein the first optical network unit and the second optical network unit are two adjacent optical network units, the first optical network unit is used for transmitting a first optical burst signal in a first uplink burst time slot, the second optical network unit is used for transmitting a second optical burst signal in a second uplink burst time slot, the first uplink burst time slot is adjacent to the second uplink burst time slot, the first uplink burst time slot is positioned behind the second uplink burst time slot, the burst receiving power of the first optical network unit and the burst receiving power of the second optical network unit can be subjected to a difference operation to obtain a power difference value, a first bias voltage adjustment value of a photodiode is calculated by utilizing the power difference value, the photodiode is used for performing photoelectric conversion on the first optical burst signal and the second optical burst signal, and the bias voltage of the photodiode is adjusted by utilizing the first bias voltage adjustment value before the first uplink burst time slot after the second uplink burst time slot, so that the bias voltage of the power difference value is smaller than zero or the bias voltage of the photodiode is increased.

Drawings

In order that the detailed description of the present application may be clearly understood, a brief description of the drawings will be provided below. It is apparent that these figures are only some of the embodiments of the present application.

Fig. 1 is a schematic structural diagram of a passive optical network system;

FIG. 2 is a schematic diagram illustrating transmission of an optical burst signal;

FIG. 3 is a flowchart of a control method according to an embodiment of the present disclosure;

fig. 4 is a schematic structural diagram of a control device according to an embodiment of the present application;

fig. 5 is a schematic structural diagram of an optical line terminal according to an embodiment of the present application.

Detailed Description

The embodiment of the application provides a control method, a control device, a control chip, an optical line terminal and a passive optical network, which reduce burst establishment time and improve transmission efficiency.

The terms "first," "second," "third," "fourth" and the like in the description and in the claims of this application and in the above-described figures, if any, are used for distinguishing between similar objects and not necessarily for describing a particular sequential or chronological order. It is to be understood that the data so used may be interchanged where appropriate such that the embodiments described herein may be implemented in other sequences than those illustrated or otherwise described herein. Furthermore, the terms "comprises," "comprising," and "having," and any variations thereof, are intended to cover a non-exclusive inclusion, such that a process, method, system, article, or apparatus that comprises a list of steps or elements is not necessarily limited to those steps or elements expressly listed but may include other steps or elements not expressly listed or inherent to such process, method, article, or apparatus.

After the OLT receives one optical burst signal, a certain reception preparation time is required to perform TIA charge and discharge, so that the sampling threshold of the TIA is matched with the received optical power of the next optical burst signal, so that the next optical burst signal is accurately received, the reception preparation time of the OLT becomes a burst establishment time, and the burst establishment time of each ONU is the same time at present. Because the charging and discharging speed of TIA is limited by hardware, burst setup time is generally longer, and when the burst receiving power difference between two adjacent optical burst signals is larger, the required burst setup time will be longer, so that the transmission efficiency in PON transmission network is lower.

That is, for the ONUs mounted on the same OLT, the burst setup time and the dynamic range of the burst received power are closely related, when the burst setup time is shorter, the dynamic range of the allowable burst received power is smaller, meanwhile, the difference value of the burst received power between adjacent ONUs is smaller, and when the burst setup time is longer, the dynamic range of the allowable burst received power is larger, and meanwhile, the difference value of the burst received power before the adjacent ONUs is larger.

At present, enough burst establishment time is reserved in a PON system to ensure enough burst receiving power dynamic range, however, when the topology structure of the PON network changes to increase the dynamic range of the burst receiving power, the burst establishment time needs to be increased to meet the normal operation of the system, and by increasing the burst establishment time in exchange for the dynamic range of the burst receiving power, timeslots of signal transmission are wasted, so that the transmission rate of the entire PON transmission network is reduced.

Referring to fig. 2, an optical burst signal transmission schematic is shown, in which ONU-1 transmits in a first time slot, ONU-2 transmits in a second time slot, ONU-3 transmits in a third time sequence, and a burst setup time is provided between the first time slot and the second time slot, and a burst setup time is also provided between the second time slot and the third time slot. If the difference between the burst receiving powers of ONU-1 and ONU-2 is large, the burst setup time before the first time slot and the second time slot is required to be long, so that the burst setup time is increased, resulting in time waste.

At present, a TIA circuit in a PON system may include a plurality of sub-TIAs, and according to different incoming currents, the plurality of TIAs are switched through hardware, so as to realize switching of various amplification gains, thereby realizing rapid charging and discharging of the TIA circuit. However, this approach requires additional device cost, while the switchable sub-TIA is limited due to hardware circuit limitations and does not allow for flexible gain switching.

Based on the above technical problems, the embodiments of the present application provide a control method, an apparatus, a chip, an optical line terminal, and a passive optical network, where the first optical network unit and the second optical network unit are two adjacent optical network units, the first optical network unit is configured to transmit a first optical burst signal in a first uplink burst slot, the second optical network unit is configured to transmit a second optical burst signal in a second uplink burst slot, the first uplink burst slot is adjacent to the second uplink burst slot, and the first uplink burst slot is located after the second uplink burst slot, and then a difference between burst receive power of the first optical network unit and burst receive power of the second optical network unit may be calculated by using the difference between the power and the first bias adjustment value of the photodiode, the photodiode is configured to perform photoelectric conversion on the first optical burst signal and the second optical burst signal, and before the first uplink burst slot after the second uplink burst slot, the bias adjustment value of the photodiode is used to adjust the bias voltage of the photodiode, so that the difference between the power is greater than zero, and the bias voltage of the photodiode is reduced or the bias voltage of the photodiode is increased by less than zero.

In order to make the above objects, features and advantages of the present application more comprehensible, embodiments accompanied with figures are described in detail below.

Referring to fig. 3, a flowchart of a control method provided in an embodiment of the present application is shown, where the method is applied to an OLT, and may be performed by a control module in the OLT, or may be performed by an optical communication digital signal processing (optical digital signal process, oDSP) chip in the OLT, and the method may include the following steps.

S101, performing a difference operation on the burst receiving power of the first optical network unit and the burst receiving power of the second optical network unit to obtain a power difference value.

In this embodiment of the present application, the first optical network unit and the second optical network unit are two adjacent optical network units, which are connected to the same OLT, and the OLT may sequentially receive, according to timeslots, optical burst signals sent by the first optical network and the second optical network. Specifically, the first optical network unit sends a first optical burst signal in a first uplink burst time slot, the second optical network unit sends a second optical burst signal in a second uplink burst time slot, the first uplink burst time slot is adjacent to the second uplink burst time slot, and the first uplink burst time slot is located after the second uplink burst time slot, that is, the first optical network unit sends the first optical burst signal to the OLT after the second optical network unit sends the second optical burst signal.

The first optical network unit and the second optical network unit each have burst receiving power, and the burst receiving powers of the first optical network unit and the second optical network unit are different, because the distances between the different optical network units and the OLT are different, the transmitting optical powers of the different optical network units are not necessarily the same, so that the optical powers of the optical burst signals transmitted by the different optical network units reaching the OLT are different. That is, the burst received power of the first optical network unit is related to the distance between the first optical network unit and the OLT, and the burst received power of the second optical network unit is related to the distance between the second optical network unit and the OLT.

Because the first optical network unit and the second optical network unit are two adjacent optical network units, when the difference of burst receiving power of the first optical network unit and the second optical network unit is larger, longer burst establishing time is required to be set, and time waste is easily caused. Therefore, in the embodiment of the present application, the burst receiving power of the first optical network unit and the burst receiving power of the second optical network unit may be subjected to a difference operation, a power difference between the first optical network unit and the burst receiving power of the first optical network unit and the burst receiving power of the second optical network unit may be calculated, and the bias voltage of the photodiode may be adjusted according to the power difference, so as to reduce the burst establishment time.

The burst receive power of the first optical network unit and the burst receive power of the second optical network unit may be obtained from a medium access control (media access control, MAC) module, so as to set a bias voltage of a suitable photodiode for the second optical burst signal of the second optical network unit in advance, which is beneficial to reducing burst setup time. Specifically, a bandwidth Map (BW Map) may be obtained from the MAC module, and an uplink burst slot and burst reception power of each optical network unit may be obtained from the bandwidth Map. For example, the oDSP chip may acquire the burst received power of the first optical network unit and the burst received power of the second optical network using an interface between the oDSP chip and the MAC module.

Wherein the burst received power of the first optical network unit can be denoted as P _n+1 The burst received power of the second optical network unit may be denoted as P _n The power difference deltap between the burst received power of the first optical network unit and the burst received power of the second optical network unit _n Can be expressed as DeltaP _n ＝P _n+1 -P _n 。

The calculating of the power difference between the burst received power of the first optical network unit and the burst received power of the second optical network may be performed according to a certain period, where the period may be one or more burst received periods, and one burst received period includes uplink burst time slots of all ONUs connected to the OLT. For example, the calculation of the power difference of the received powers of all adjacent ONUs in one period may be completed in advance.

The first uplink burst time slot and the second uplink burst time slot belong to a first burst receiving period, a second burst receiving period is provided before the first burst receiving period, the second burst receiving period is a burst receiving period adjacent to the first burst receiving period, the burst receiving power of the first optical network unit can be determined according to the burst receiving power of the first optical network unit in the second burst receiving period, and the burst receiving power of the second optical network unit can be determined according to the burst receiving power of the second optical network unit in the second burst receiving period. The method is characterized in that the burst receiving power of the first optical network unit and the burst receiving power of the second optical network unit may have small dynamic changes in the operation process, and the burst receiving power of the second optical network unit in the subsequent burst receiving period are determined according to the burst receiving power of the first optical network unit and the burst receiving power of the second optical network unit in the previous burst receiving period, so that the obtained burst receiving power is accurate and timely, and the burst establishing time is reduced in a targeted manner.

In this embodiment of the present application, the burst receiving power of the first optical network unit in the second burst period is determined according to a first detection current of the first optical network unit in the second burst period, where the first detection current is obtained by performing, by using the photodiode, photoelectric conversion on a third burst signal sent by the first optical network unit in the second burst period. Specifically, the burst receiving power corresponding to the first detection current can be calculated according to the relation between the burst receiving power and the detection current, so that the calculated value of the burst receiving power of the optical network unit is more accurate, and the burst establishing time is reduced in a targeted manner.

In this embodiment of the present application, the burst receiving power of the second optical network in the second burst period is determined according to a second detection current of the second optical network unit in the second burst period, where the second detection is obtained by performing, by using the photodiode, photoelectric conversion on a fourth burst signal sent by the second optical network unit in the second burst period. Specifically, the burst receiving power corresponding to the second detection current can be calculated according to the relation between the burst receiving power and the detection current, so that the calculated value of the burst receiving power of the optical network unit is more accurate, and the burst establishing time is reduced in a targeted manner.

S102, calculating a first bias voltage adjustment value of the photodiode by using the power difference value.

In this embodiment of the present application, after receiving an optical burst signal, the photodiode is configured to perform photoelectric conversion on the optical burst signal, so as to obtain a detection current corresponding to the optical burst signal, that is, the photodiode may perform photoelectric conversion on the first optical burst signal and the second optical burst signal. The photodiode can be an avalanche diode (avalanche photodiode, APD), has larger photoelectric conversion efficiency, namely avalanche gain in the photoelectric conversion process, can obtain larger detection current, and reduces the transmission loss of signals. The photodiode needs to apply a certain bias voltage when in operation, and the larger the bias voltage is, the larger the photoelectric conversion gain is, and the larger the photoelectric conversion current is.

In this embodiment of the present application, the first bias adjustment value of the photodiode may be calculated according to a power difference between the burst received power of the first optical network unit and the burst received power of the second optical network unit. Specifically, the absolute value of the power difference value may be positively correlated with the absolute value of the first bias voltage adjustment value, so that the larger the absolute value of the power difference value is, the larger the absolute value of the first bias voltage adjustment value is, which is favorable for making the detection current corresponding to the second optical network unit approach the detection current corresponding to the first optical network unit, and is favorable for reducing the burst establishment time. In practice, the first bias adjustment value DeltaU _n Can be the first adjustment coefficient alpha and the power difference delta P _n The first adjustment coefficient alpha is a constant, i.e. DeltaU _n ＝ΔP _n * And alpha, determining the first bias voltage adjusting value according to the power difference value, wherein the first bias voltage adjusting value is proportional to the power difference value, and the obtained first bias voltage adjusting value is reasonable and is beneficial to reducing the burst establishment time. The first adjustment coefficient α may be a negative value when the first adjustment coefficient α is selected according to an actual hardware system, so that the calculated first bias adjustment value is a negative value when the power difference is a positive value, and the calculated first bias adjustment value is a positive value when the power difference is a negative value.

S103, before the second uplink burst time slot is followed by the second uplink burst time slot, the bias voltage of the photodiode is adjusted by using the first bias voltage adjustment value.

In this embodiment of the present application, since the power difference between the burst received power of the first optical network unit and the burst received power of the second optical network unit may represent a change in the burst received power of the first optical network unit and the burst received power of the second optical network unit, under a condition that the bias voltage of the photodiode is unchanged, the detected current obtained after performing photoelectric conversion on the optical burst signals sent by the first optical network unit and the second optical network unit also has a corresponding change, the TIA connected to the photodiode needs to adapt to different detected currents through charging and discharging, and the larger the power difference is, the larger the difference in detected current is, and the longer the required charging and discharging time is.

Thus, burst can be performed in the first uplinkAnd adjusting the bias voltage of the photodiode by using the first bias voltage adjusting value between the time slot and the second uplink burst time slot to realize rough adjustment of the bias voltage of the photodiode. Since the first bias adjustment value is related to the power difference, the adjusted bias voltage of the photodiode is also related to the power difference, thereby reducing the bias voltage of the photodiode when the power difference is greater than zero or increasing the bias voltage of the photodiode when the power difference is less than zero. For example, the original bias voltage of the photodiode is U _o When the power difference is larger than zero, the first bias voltage adjusting value is negative, and after the bias voltage of the photodiode is adjusted by the first bias voltage adjusting value, the bias voltage of the photodiode is U _o +ΔU _n Less than U _o The method comprises the steps of carrying out a first treatment on the surface of the When the power difference is smaller than zero, the first bias voltage adjusting value is positive, and after the bias voltage of the photodiode is adjusted by the first bias voltage adjusting value, the bias voltage of the photodiode is U _o +ΔU _n Greater than U _o 。

That is, in this embodiment of the present application, for the second optical network unit with burst receiving power larger than the first optical network unit, the bias voltage of the photodiode may be set smaller, so that the photoelectric conversion gain of the photodiode is smaller, the generated detection current corresponding to the second optical network unit is reduced to be closer to the detection current corresponding to the first optical network unit, so that the sampling threshold variation range of the TIA connected to the photodiode is reduced, the burst setup time is reduced, and for the second optical network unit with burst receiving power smaller than the first optical network unit, the bias voltage of the photodiode may be set larger, so that the photoelectric conversion gain of the photodiode is larger, the generated detection current corresponding to the second optical network unit is improved to be closer to the detection current corresponding to the first optical network unit, and the sampling threshold variation range of the TIA connected to the photodiode is reduced, so that the burst setup time is reduced. Thus, a larger power difference in burst received power can be tolerated with the burst set-up time unchanged. Under the condition that the power difference index of the burst receiving power is unchanged, the burst establishing time can be shortened to exchange the transmission payload, lower cost and flexible design can be realized, and the dynamic range of the burst receiving power of the system is enlarged on the premise of not reducing the net rate of the system.

The method may specifically send a digital value of the first bias adjustment value to a digital-to-analog converter (DAC) to obtain a first analog voltage corresponding to the first bias adjustment value by using the DAC, and load the first analog voltage into a power supply circuit of the photodiode, so as to accurately adjust the bias voltage of the photodiode. The digital quantity of the first bias voltage adjustment value is sent to the digital-to-analog converter, and accurate transmission of the data quantity can be facilitated through a serial peripheral interface (serial peripheral interface, SPI) protocol or an internal integrated circuit (inter-integrated circuit, I2C) protocol.

In this embodiment of the present application, after a plurality of optical burst signals are received, a plurality of detection currents may be obtained by performing photoelectric conversion on the plurality of optical burst signals by using a photodiode, and a plurality of recovery signals are obtained by processing the plurality of detection currents, where the plurality of recovery signals respectively include service signals carried by the plurality of optical burst signals. The optical burst signal may include a first optical burst signal and a second optical burst signal, and may further include other optical burst signals sent by other optical network units, and after receiving the second optical burst signal of the second optical network unit, the optical burst signal may further obtain a detection current after photoelectric conversion of the second optical burst signal by the photodiode, and then, process the detection current to obtain a recovery signal, where the recovery signal includes a service signal carried by the second optical burst signal, so as to implement smooth communication between the optical network unit and the optical line terminal; similarly, after receiving the first optical burst signal of the first optical network unit, the detection current after the photodiode performs photoelectric conversion on the first optical burst signal can be obtained, and then the detection current is processed to obtain a recovery signal, where the recovery signal includes a service signal carried by the first optical burst signal. Processing the detected current to obtain a recovery signal may include: the detection current is amplified through TIA, and the detection current is processed through oDSP chip.

In this embodiment of the present application, the recovery signal may further be monitored periodically, where the recovery signal may include recovery signals corresponding to a plurality of ONUs, and a period for monitoring the recovery signal may be one or more burst receiving periods, where one burst receiving period includes uplink burst timeslots of all ONUs connected to the OLT.

The method comprises the steps that through periodic monitoring of a recovery signal, a performance fluctuation value between a transmission performance parameter of a first period and an insertion loss performance parameter of a second period can be obtained, wherein the first period and the second period are two adjacent periods, and the first period is before the second period; then, a second bias adjustment value of the photodiode can be calculated according to the performance fluctuation value; and after the second period is finished, the bias voltage of the photodiode is adjusted by using the second bias voltage adjustment value so as to reduce the performance fluctuation value of a third period after the second period, and fine adjustment of the bias voltage of the photodiode is realized. Therefore, the transmission performance of the system can be optimized as a whole through the performance monitoring feedback adjustment mechanism, the tolerance of the influence on the system performance caused by environmental fluctuation is higher, and the gain adjustment granularity is low and the adjustment scheme is more flexible. The transmission performance parameter includes at least one of a signal-to-noise ratio (SNR), a Bit Error Rate (BER), and an error vector magnitude (error vector magnitude, EVM), so that the performance fluctuation value more comprehensively reflects the transmission performance, and the second bias adjustment value obtained according to the performance fluctuation value is more targeted, so that the transmission performance of the system is optimized as a whole.

In particular, the performance parameter of the second period may be expressed as B _n+1 The performance parameter of the first period may be denoted as B _n Performance fluctuation value Δb between the performance parameter of the first cycle and the performance parameter of the second cycle _n Can be expressed as DeltaB _n ＝B _n+1 -B _n . The absolute value of the performance fluctuation value and the absolute value of the second bias adjustment value are positively correlated such that the larger the absolute value of the performance fluctuation value is, the larger the absolute value of the second bias adjustment value is. In particular, the second bias adjustment value DeltaV _n Can be the second adjustment coefficient beta and the performance fluctuation value delta B _n The second adjustment coefficient beta is constant, i.e. DeltaV _n ＝ΔB _n * Beta, adjust the second biasThe integral value is determined according to the performance fluctuation value, and the second bias voltage adjustment value is proportional to the performance fluctuation value, so that the obtained second bias voltage adjustment value is reasonable, and the burst establishment time is reduced. The second adjustment coefficient can be a moderate value according to the performance convergence speed and the system performance fluctuation speed. The second adjustment coefficient can also be based on the performance fluctuation value DeltaB _n Different values are selected for the range of (a).

The method for adjusting the bias voltage of the photodiode by using the second bias voltage adjustment value may specifically be that a digital quantity of the second bias voltage adjustment value is sent to the digital-to-analog converter, so as to obtain a second analog voltage corresponding to the second bias voltage adjustment value by using the digital-to-analog converter, and the second analog voltage is loaded into a power supply circuit of the photodiode, so that the bias voltage of the photodiode can be accurately adjusted. The digital quantity of the second bias voltage adjustment value is sent to the digital-to-analog converter, and accurate transmission of the data quantity can be facilitated through an SPI protocol or an I2C protocol and the like.

After the bias voltage of the photodiode is adjusted by the first bias voltage adjusting value, and after the bias voltage of the photodiode is adjusted by the second bias voltage adjusting value, the mapping relation between the burst receiving power and the detection current corresponding to each ONU can be determined, the mapping relation between the burst receiving power and the detection current reflects the photoelectric conversion gain of the photodiode, after the bias voltage of the photodiode is adjusted, the photoelectric conversion gain of the photodiode is correspondingly changed, the mapping relation between the burst receiving power of the burst signal and the detection current is also changed, so that the mapping relation between the burst receiving power and the detection current can be updated, and the burst receiving power of the optical network unit in the burst period can be obtained according to the detection current in the burst receiving period in the next burst receiving period. Specifically, the mapping relationship may be sent to the MAC module.

The embodiment of the application provides a control method, in which a first optical network unit and a second optical network unit are two adjacent optical network units, the first optical network unit is used for transmitting a first optical burst signal in a first uplink burst time slot, the second optical network unit is used for transmitting a second optical burst signal in a second uplink burst time slot, the first uplink burst time slot is adjacent to the second uplink burst time slot, and the first uplink burst time slot is located behind the second uplink burst time slot, so that a difference value of power can be obtained by performing a difference operation on burst receiving power of the first optical network unit and burst receiving power of the second optical network unit, a first bias voltage adjustment value of a photodiode is calculated by using the difference value of power, the photodiode is used for performing photoelectric conversion on the first optical burst signal and the second optical burst signal, and before the first uplink burst time slot is used for adjusting the bias voltage of the photodiode after the second uplink burst time slot, the bias voltage of the photodiode is reduced when the difference value of power is greater than zero, or the bias voltage of the photodiode is increased when the difference value of power is less than zero. That is, in this embodiment of the present application, for the second optical network unit with burst receiving power larger than the first optical network unit, the bias voltage of the photodiode may be set smaller, so that the photoelectric conversion gain of the photodiode is smaller, the generated detection current corresponding to the second optical network unit is reduced to be closer to the detection current corresponding to the first optical network unit, so that the sampling threshold variation range of the TIA connected to the photodiode is reduced, the burst setup time is reduced, and for the second optical network unit with burst receiving power smaller than the first optical network unit, the bias voltage of the photodiode may be set larger, so that the photoelectric conversion gain of the photodiode is larger, the generated detection current corresponding to the second optical network unit is improved to be closer to the detection current corresponding to the first optical network unit, and the sampling threshold variation range of the TIA connected to the photodiode is reduced, so that the burst setup time is reduced. Therefore, lower cost and flexible design can be realized, and the dynamic range of the burst receiving power of the system is increased without reducing the net rate of the system.

Based on a control method provided by the embodiment of the present application, the embodiment of the present application further provides a control device, and referring to fig. 4, a schematic structural diagram of the control device provided by the embodiment of the present application is provided, where the device is applied to an OLT, and may be executed by the control device in the OLT, and may also be an optical communication digital signal processing (oDSP) chip in the OLT, and the device includes:

a power difference calculation unit 110, configured to perform a difference operation on the burst received power of the first optical network unit and the burst received power of the second optical network unit to obtain a power difference; the first optical network unit is configured to send a first optical burst signal in a first uplink burst slot, the second optical network unit sends a second optical burst signal in a second uplink burst slot, the first uplink burst slot is adjacent to the second uplink burst slot, and the first uplink burst slot is located after the second uplink burst slot;

a bias adjustment value calculating unit 120, configured to calculate a first bias adjustment value of a photodiode according to the power difference, where the photodiode is configured to perform photoelectric conversion on the first optical burst signal and the second optical burst signal;

And an adjusting unit 130, configured to adjust the bias voltage of the photodiode by using the first bias voltage adjustment value before the first uplink burst slot after the second uplink burst slot, so that the bias voltage of the photodiode decreases when the power difference is greater than zero, or the bias voltage of the photodiode increases when the power difference is less than zero.

In some possible embodiments, the apparatus further comprises:

In some possible embodiments, the photodiode is an avalanche diode.

The embodiment of the application provides a control device, where a first optical network unit and a second optical network unit are two adjacent optical network units, the first optical network unit is configured to send a first optical burst signal in a first uplink burst slot, the second optical network unit is configured to send a second optical burst signal in a second uplink burst slot, the first uplink burst slot is adjacent to the second uplink burst slot, and the first uplink burst slot is located behind the second uplink burst slot, so that a difference between burst received power of the first optical network unit and burst received power of the second optical network unit can be calculated by a difference method to obtain a power difference value, a first bias adjustment value of a photodiode is calculated by using the power difference value, the photodiode is configured to perform photoelectric conversion on the first optical burst signal and the second optical burst signal, and before the first uplink burst slot is located behind the second uplink burst slot, the bias of the photodiode is adjusted by using the first bias adjustment value, so that the bias voltage of the photodiode is reduced when the power difference value is greater than zero, or the bias voltage of the photodiode is increased when the power difference value is less than zero. That is, in this embodiment of the present application, for the second optical network unit with burst receiving power larger than the first optical network unit, the bias voltage of the photodiode may be set smaller, so that the photoelectric conversion gain of the photodiode is smaller, the generated detection current corresponding to the second optical network unit is reduced to be closer to the detection current corresponding to the first optical network unit, so that the sampling threshold variation range of the TIA connected to the photodiode is reduced, the burst setup time is reduced, and for the second optical network unit with burst receiving power smaller than the first optical network unit, the bias voltage of the photodiode may be set larger, so that the photoelectric conversion gain of the photodiode is larger, the generated detection current corresponding to the second optical network unit is improved to be closer to the detection current corresponding to the first optical network unit, and the sampling threshold variation range of the TIA connected to the photodiode is reduced, so that the burst setup time is reduced. Therefore, lower cost and flexible design can be realized, and the dynamic range of the burst receiving power of the system is increased without reducing the net rate of the system.

Based on the control method provided by the embodiment of the application, the embodiment of the application also provides a control chip, and the control chip is used for executing the control method, and the control chip can be an oDSP chip in the OLT.

Based on the control method and the control chip provided in the embodiments of the present application, the embodiments of the present application further provide an optical line terminal, and referring to fig. 5, which is a schematic structural diagram of the optical line terminal provided in the embodiments of the present application, the optical line terminal includes the foregoing control chip, and the optical line terminal may further include a photodiode and a transimpedance amplifier (TIA) 20, where the photodiode is configured to perform photoelectric conversion on a burst signal to obtain a detection current, and the TIA 20 is configured to amplify the detection current output by the photodiode.

The control chip may be an oDSP chip and the photodiode may be an avalanche diode (APD), i.e. the optical line termination may comprise an oDSP chip 30, an APD 10, a TIA 20. When the control chip is an oDSP chip 30 in the OLT, the oDSP chip 30 is connected with the TIA 20 and is used for processing the detection current output by the TIA 20 to obtain a recovery signal.

The optical line terminal may also include a digital-to-analog converter (DAC) 50, with the power supply circuit of the APD 10 having an initial bias voltage U ₀ The bias voltage U can be adjusted by DAC 50 _k Loaded into a power supply circuit to adjust bias voltage U _k The first analog bias voltage may be the first bias voltage corresponding to the first bias voltage adjustment value, or the second analog voltage may be the second analog voltage corresponding to the second bias voltage adjustment value.

The optical line terminal further includes a Medium Access Control (MAC) module 40, and the oDSP chip may acquire burst reception power of the first optical network unit and burst reception power of the second optical network using an interface between the oDSP chip 30 and the MAC module 40.

Based on the optical line terminal provided in the embodiment of the present application, the embodiment of the present application further provides a passive optical network, including:

a first optical network unit and a second optical network unit;

an optical line terminal; the optical line terminal is respectively connected with the first optical network unit and the second optical network unit.

In this specification, each embodiment is described in a progressive manner, and identical and similar parts of each embodiment are all referred to each other, and each embodiment mainly describes differences from other embodiments. In particular, for the device, chip and optical line terminal, optical network unit embodiments, since they are substantially similar to the method embodiments, the description is relatively simple, and the relevant points are referred to in the description of the method embodiments.

The foregoing is a specific implementation of the present application. It should be understood that the above-described embodiments are only for illustrating the technical solution of the present application, and are not limiting thereof; although the present application has been described in detail with reference to the foregoing embodiments, it should be understood by those of ordinary skill in the art that: the technical scheme described in the foregoing embodiments can be modified or some technical features thereof can be replaced by equivalents; such modifications and substitutions do not depart from the spirit of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A control method, characterized by comprising:

performing a difference operation on the burst receiving power of the first optical network unit and the burst receiving power of the second optical network unit to obtain a power difference value; the first optical network unit is configured to send a first optical burst signal in a first uplink burst slot, the second optical network unit sends a second optical burst signal in a second uplink burst slot, the first uplink burst slot is adjacent to the second uplink burst slot, and the first uplink burst slot is located after the second uplink burst slot;

calculating a first bias voltage adjustment value of a photodiode by using the power difference value, wherein the photodiode is used for performing photoelectric conversion on the first optical burst signal and the second optical burst signal;

And before the first uplink burst time slot after the second uplink burst time slot, adjusting the bias voltage of the photodiode by using the first bias voltage adjusting value to reduce the bias voltage of the photodiode when the power difference value is larger than zero or increase the bias voltage of the photodiode when the power difference value is smaller than zero.

2. The method of claim 1, wherein an absolute value of the power difference and an absolute value of the first bias voltage adjustment value are positively correlated.

3. The method of claim 2, wherein the first bias voltage adjustment value is a product of a first adjustment coefficient and the power difference value, the first adjustment coefficient being a constant.

4. The method according to claim 1, wherein the method further comprises:

5. The method according to claim 4, wherein the method further comprises:

6. The method of claim 5, wherein the transmission performance parameter comprises at least one of signal-to-noise ratio, bit error rate, and error vector magnitude.

7. The method of claim 5, wherein the second bias adjustment value is a product of a second adjustment coefficient and the performance fluctuation value, the second adjustment coefficient being a constant.

8. The method of any of claims 5-7, wherein adjusting the bias voltage of the photodiode with the first bias voltage adjustment value comprises:

9. The method of claim 8, wherein the digital amount of the first bias voltage adjustment value and the digital amount of the second bias voltage adjustment value are sent to the digital-to-analog converter via a serial peripheral interface, SPI, protocol or an internal integrated circuit, I2C, protocol.

10. The method of any of claims 1-7, wherein prior to calculating the power difference, the method further comprises:

11. The method according to any of claims 1-7, wherein the first uplink burst slot and the second uplink burst slot belong to a first burst reception period;

12. The method of claim 11, wherein the burst received power of the first optical network unit during the second burst period is determined based on a first detected current of the first optical network unit during the second burst period; the first detection current is obtained by photoelectric conversion of a third burst signal sent by the first optical network unit in a second burst period by the photodiode;

13. The method according to claim 12, wherein the method further comprises:

14. The method of any one of claims 1-7, wherein the photodiode is an avalanche diode.

15. A control apparatus, characterized by comprising:

16. The apparatus of claim 15, wherein an absolute value of the power difference and an absolute value of the first bias voltage adjustment value are positively correlated.

17. The apparatus of claim 16, wherein the first bias voltage adjustment value is a product of a first adjustment coefficient and the power difference value, the first adjustment coefficient being a constant.

18. The method of claim 15, wherein the apparatus further comprises:

19. The apparatus of claim 18, wherein the apparatus further comprises:

20. The apparatus of claim 19, wherein the transmission performance parameter comprises at least one of a signal-to-noise ratio, a bit error rate, and an error vector magnitude.

21. The apparatus of claim 19, wherein the second bias adjustment value is a product of a second adjustment coefficient and the performance fluctuation value, the second adjustment coefficient being a constant.

22. The apparatus of any of claims 19-21, wherein said adjusting the bias voltage of the photodiode with the first bias voltage adjustment value comprises:

23. The apparatus of claim 22, wherein the digital to analog converter is configured to send the digital amount of the first bias voltage adjustment value and the digital amount of the second bias voltage adjustment value via a serial peripheral interface, SPI, protocol or an internal integrated circuit, I2C, protocol.

24. The apparatus according to any one of claims 15-21, wherein the apparatus further comprises:

25. The apparatus according to any of claims 15-21, wherein the first uplink burst slot and the second uplink burst slot belong to a first burst reception period;

26. The apparatus of claim 25, wherein the burst received power of the first optical network unit during the second burst period is determined based on a first detected current of the first optical network unit during the second burst period; the first detection current is obtained by photoelectric conversion of a third burst signal sent by the first optical network unit in a second burst period by the photodiode;

27. The apparatus of claim 26, wherein the apparatus further comprises:

28. The apparatus of any one of claims 15-21, wherein the photodiode is an avalanche diode.

29. A control chip for performing the control method of any one of claims 1-14.

30. The control chip of claim 29, wherein the control chip is an optical communication digital signal processing chip.

31. An optical line terminal comprising a control chip as claimed in claim 29 or 30.

32. The optical line termination of claim 31, further comprising a photodiode and a transimpedance amplifier; the photodiode is used for carrying out photoelectric conversion on the burst signal to obtain detection current, and the transimpedance amplifier is used for amplifying the detection current output by the photodiode.

33. A passive optical network, comprising:

a first optical network unit and a second optical network unit;

an optical line terminal according to claim 31 or 32; the optical line terminal is respectively connected with the first optical network unit and the second optical network unit.