CN-121984451-A - Low-cost PON link SOA bias current driving method

CN121984451ACN 121984451 ACN121984451 ACN 121984451ACN-121984451-A

Abstract

The invention discloses a driving method of low-cost SOA bias current of a PON link, and belongs to the technical field of optical communication. By introducing a current distribution network formed by the adjustable current mirror, a local energy storage capacitor pre-charging mechanism and a central cooperative controller, the simultaneous, independent and stable biasing of the laser and the semiconductor optical amplifier during the PON uplink burst transmission is realized. The central cooperative controller configures the proportion of the current mirror in advance and pre-charges the energy storage capacitor before the burst starts according to the uplink burst enabling signal, maintains the power supply simultaneously during the burst period, and cuts off the power supply after the burst ends so as to reduce the power consumption. Compared with the prior art, the invention completely avoids the use of an external independent current source chip, obviously reduces the bill of materials cost and the complexity of the system, ensures the burst response speed, the bias precision and the nonlinear distortion suppression effect, and can be widely applied to passive optical network systems with high link budget.

Inventors

LIU KE
SONG JIANWEN
LING LU

Assignees

成都三维原光通讯技术有限公司

Dates

Publication Date: 20260505
Application Date: 20260408

Claims (10)

1. A driving method of low-cost PON link SOA bias current is applied to a driving system, and the system comprises a single-channel constant current source and is characterized by comprising the following steps: providing a current distribution network, the input end of the current distribution network being connected to the output end of the single-channel constant current source, the current distribution network having at least two output ends for respectively connecting a laser as a first load and a semiconductor optical amplifier as a second load; acquiring a state signal representing the uplink burst transmission of the PON link in real time through a central cooperative controller; The central cooperative controller dynamically controls a current distribution network in a burst transmission period according to the state signal, and distributes the total current output by the single-channel constant current source to a first load and a second load at the same time, wherein the current distributed to the first load meets the bias requirement of the laser, and the current distributed to the second load meets the bias requirement of the semiconductor optical amplifier; During the non-bursty transmission periods, the central cooperative controller controls the current distribution network to cut off or reduce power to the first load and the second load.
2. The method for driving the SOA bias current of the low-cost PON link according to claim 1, wherein the current distribution network is specifically composed of a first adjustable current mirror and a second adjustable current mirror which are connected in parallel, wherein the input ends of the first adjustable current mirror and the second adjustable current mirror are commonly connected to the output end of a single constant current source, the output ends of the first adjustable current mirror and the second adjustable current mirror are respectively connected to a first load and a second load, and the central cooperative controller is used for realizing proportional distribution of total current between the two loads by adjusting the mirror image proportion of the first adjustable current mirror and the second adjustable current mirror.
3. The method for driving the SOA bias current of the low-cost PON link according to claim 2, wherein the central cooperative controller is configured to control the current according to the target bias current of the laser And a target bias current for a semiconductor optical amplifier Setting the mirror proportion of the first adjustable current mirror Mirror ratio to the second adjustable current mirror The specific relation is as follows: Wherein, the Is the total current output by a single constant current source and meets the following requirements While ensuring To ensure that the total current is fully divided between the two loads.
4. The method for driving the low-cost PON link SOA bias current according to claim 1, wherein the current distribution network is further provided with a first local energy storage capacitor and a second local energy storage capacitor, the first local energy storage capacitor is connected in parallel with two ends of a first load, the second local energy storage capacitor is connected in parallel with two ends of a second load, the local energy storage capacitor is used for being precharged by a single constant current source in a non-burst transmission period and supplying power to the corresponding load together with the single constant current source at a burst transmission starting moment, and therefore transient current requirements caused by load switching are compensated, and voltage drop is restrained.
5. The method for driving low cost PON link SOA bias current as set forth in claim 4, wherein the central cooperative controller is configured to Before the effective edge of burst transmission enabling signal comes, the current distribution network is controlled to switch the single-channel constant current source to a ready-to-supply state and precharge the local energy storage capacitor, and the current distribution network is controlled to advance The following conditions are simultaneously satisfied: Wherein, the Establishing a time constant for the load current, which is determined by the carrier life of the semiconductor optical amplifier and the circuit time constant; the minimum guard interval specified for the PON link standard ensures that the current switching does not occupy a valid transmission slot.
6. The method for driving the low-cost PON link SOA bias current according to claim 1, further comprising the step of cross interference suppression, wherein the step of monitoring voltage fluctuation conditions of the output end of the single-channel constant current source in real time, and the step of adjusting control time sequence or current distribution proportion of the current distribution network by the central cooperative controller correspondingly in a subsequent burst transmission period when the detected voltage fluctuation amplitude exceeds a preset threshold Vth so as to smooth the current change process and suppress power supply voltage oscillation caused by load switching.
7. The method for driving low cost PON link SOA bias current of claim 1, wherein when the driving system is required to drive a plurality of loads simultaneously, the number of loads is N and N is not less than 2, the central cooperative controller maintains a load priority list and labels according to service priority And link loss Calculating the urgency factor of each load The calculation formula is as follows: Wherein, the And Is a preset weighting coefficient, and the central cooperative controller is used for controlling the weight of the weight-bearing material Distributing the current in descending order of value, if the total required current of all loads Maximum output current exceeding that of single-channel constant current source And the load with high urgency factor is preferentially met until the current resource is exhausted, the unsatisfied load pauses working in the burst period, and the current demand is recorded to be compensated in the next period.
8. The method for driving low cost PON link SOA bias current as set forth in claim 1, wherein the central cooperative controller includes a load state analysis engine, the engine maintains a dynamic model of bias current of the semiconductor optical amplifier, the model is used for controlling the load state analysis engine according to the total loss of the link And a target output optical power Calculating the required target gain to determine the corresponding target bias current, specifically, calculating the target gain according to the total loss of the link and the target output optical power : Wherein, the The output optical power of the laser is obtained by a laser bias-optical power characteristic curve, and then the corresponding target bias current is obtained by a three-dimensional lookup table calibrated offline Wherein The look-up table is stored in a non-volatile memory of the controller for ambient temperature.
9. The method for driving a low cost PON link SOA bias current of claim 1, further comprising the step of machine learning optimization by first constructing a feature vector Which comprises the following real-time monitoring data: Wherein, the In order to be at the temperature of the environment, For the bias current of the laser, The optical power is output for the semiconductor optical amplifier, In order for the link to be lost, Predicting bias current of current period by on-line learning model : Wherein, the Updating the predicted value and the reference value calculated by the load state analysis engine on line by a random gradient descent method as model parameters Weighted fusion is carried out to obtain the final bias current: Wherein the weight is And adaptively adjusting according to the prediction error of the model on the nearest sample so as to ensure that the system can smoothly transition to an optimal working point when the environment changes.
10. The method for driving a low cost PON link SOA bias current of claim 1, further comprising the step of digital predistortion compensation by first creating a nonlinear model of the semiconductor optical amplifier describing its input optical power And output optical power Relationship between: Wherein, the Is the bias current of the semiconductor optical amplifier, Is a small signal gain factor that is used to determine the gain of the signal, Is the reciprocal of the saturation coefficient of the gain, and then according to the desired linear gain Constructing a predistortion function, preprocessing a modulated signal, and obtaining the signal amplitude after predistortion Given by the formula: during burst transmission, the baseband signal to be modulated is firstly processed by a predistortion function to generate a predistortion amplitude sequence, and then the laser is driven to generate an optical signal which is amplified by the semiconductor optical amplifier and then output, so that nonlinear distortion of the semiconductor optical amplifier is counteracted, and signal transmission quality is improved.

Description

Low-cost PON link SOA bias current driving method Technical Field The invention belongs to the technical field of optical communication, and particularly relates to a driving method of low-cost SOA (service oriented architecture) bias current of a PON (passive optical network) link. Background Passive optical networks are facing increasing link budget demands as the dominant technology for fiber optic access. The introduction of a Semiconductor Optical Amplifier (SOA) can effectively compensate for optical power attenuation caused by the increase of the splitting ratio or the extension of the transmission distance, but the stable operation of the SOA depends on accurate bias current driving. In the existing PON product, an electro-absorption modulated laser (EML) driving chip usually integrates only one constant current source for laser bias, and cannot provide independent bias currents for the laser and the SOA at the same time. The conventional solution is to add a single independent current source chip (such as IDAC) or to use multiple current source integrated chips, but this significantly increases the bill of materials cost, circuit board area and control complexity, contrary to the pursuit of the PON system for the cost performance. The core contradiction of the dual load driven by the single constant current source is that the bias current requirements of the laser and the SOA are different (the laser needs to stabilize the threshold current, the SOA needs to be dynamically adjusted along with the link loss), and the laser and the SOA need to work simultaneously in the PON uplink burst mode. If the power supply is in a time-sharing power supply, the requirement of simultaneous operation in a burst period cannot be met. Therefore, there is a need for a low cost driving method based on a single constant current source that can simultaneously provide independently controllable bias currents for the laser and the SOA. Disclosure of Invention The invention aims to provide a driving method of low-cost PON link SOA bias current, which aims to solve the problem that in the prior art, the laser and the semiconductor optical amplifier cannot be independently and dynamically driven in a cooperative manner under the constraint of low cost, so that the function realization and the system cost are difficult to consider. In order to solve the technical problems, the invention adopts the following technical scheme: a driving method of low-cost PON link SOA bias current is applied to a driving system, the system comprises a single-path constant current source, and the method comprises the following steps: providing a current distribution network, the input end of the current distribution network being connected to the output end of the single-channel constant current source, the current distribution network having at least two output ends for respectively connecting a laser as a first load and a semiconductor optical amplifier as a second load; acquiring a state signal representing the uplink burst transmission of the PON link in real time through a central cooperative controller; The central cooperative controller dynamically controls a current distribution network in a burst transmission period according to the state signal, and distributes the total current output by the single-channel constant current source to a first load and a second load at the same time, wherein the current distributed to the first load meets the bias requirement of the laser, and the current distributed to the second load meets the bias requirement of the semiconductor optical amplifier; During the non-bursty transmission periods, the central cooperative controller controls the current distribution network to cut off or reduce power to the first load and the second load. According to the scheme, the current distribution network is specifically composed of a first adjustable current mirror and a second adjustable current mirror which are connected in parallel, wherein the input ends of the first adjustable current mirror and the second adjustable current mirror are commonly connected to the output end of a single-path constant current source, the output ends of the first adjustable current mirror and the second adjustable current mirror are respectively connected to a first load and a second load, and the central cooperative controller is used for realizing proportional distribution of total current between the two loads by adjusting the mirror image proportion of the first adjustable current mirror and the second adjustable current mirror. According to the scheme, the central cooperative controller is used for controlling the bias current according to the target of the laserAnd a target bias current for a semiconductor optical amplifierSetting the mirror proportion of the first adjustable current mirrorMirror ratio to the second adjustable current mirrorThe specific relation is as follows: Wherein, the Is the total current output by a sin