CN104901744B - The power equalizer of power equalization and this OLT are carried out to upward signal in the olt - Google Patents
The power equalizer of power equalization and this OLT are carried out to upward signal in the olt Download PDFInfo
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- CN104901744B CN104901744B CN201410078924.3A CN201410078924A CN104901744B CN 104901744 B CN104901744 B CN 104901744B CN 201410078924 A CN201410078924 A CN 201410078924A CN 104901744 B CN104901744 B CN 104901744B
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Abstract
The invention provides a kind of OLT for being used for the power equalizer to upward signal progress light power equalization in the olt and including this power equalizer.The power equalizer includes：Photo-coupler, it is configured as receiving the upward signal from ONU, and is Part I and Part II by its branch；Unit is monitored and controlled, is coupled with the photo-coupler, it is configured as receiving and monitors the power of the Part I of the upward signal, and produces the control signal of the incident bias current for controlling SOA；And the SOA, coupled with the photo-coupler and the monitoring and control unit, it is configured as the Part II that the upward signal is received from the photo-coupler, the control signal is received from the monitoring and control unit, its incident bias current is adjusted according to the control signal, so as to which the power of the Part II of the upward signal is adjusted into constant power level.
Description
Technical field
The present invention is generally related to EPON (PON), more specifically, is related to a kind of be used in optical line terminal
(OLT) power equalizer of power equalization is carried out in upward signal and includes the OLT of this power equalizer.
Background technology
In time division multiplexing (TDM)/time-division wavelength-division hybrid multiplex (TWDM)-PON system, due to each optical network unit
(ONU) it is different to OLT transmission range, so the luminous power that upward signal reaches OLT is also different.In addition, in gigabit
In EPON (GPON) system, the automatic growth control and clock and data recovery process of upward signal should be with firm powers
Level is completed within 44ns time, has the stricter time will to this process in the symmetrical TWDM-PON systems of 40Gb/s
Ask.In order to overcome this problem, a kind of effective method be make OLT ends receiver (Rx) receive each upward signal before
The optical power adjustment of each upward signal is horizontal to identical.In order to realize the light of this upward signal in TDM/TWDM-PON
Power equalization, it has been suggested that some schemes, including：Variable optical attenuator, or dynamic is used to adjust in each ONU
The bias current of ONU burst mode transmitters.
However, in these methods, OLT receivers must measure each ONU luminous powers and be sent out in registration phase to ONU
Send corresponding control signal.In addition, some extra components or control module are needed in each ONU.Especially, as 10 is lucky
Bit passive optical network (XGPON) starts to be examined by FSAN (FSAN) by operator's widespread deployment, and TWDM-PON
Consider the primary solutions as next-generation passive optical network (NGPON), upward signal future is up to 10Gb/s data transfer rates, such as
Fruit is if each ONU end realizes ascending power equilibrium, it will produces higher cost of implementation.
Accordingly, it is desirable to be able to up light power equalization is realized in the olt to reduce ONU end complexity and cost.
Fig. 1 show it is a kind of in the prior art in the olt carry out light power equalization scheme schematic diagram (referring to
Ting-Tsan Huang, et.al, Optical power equalization for upstream traffic with
Injection-locked Fabry Perot lasers in TDM-PON, optical communications, 283
(2010)).As shown in fig. 1, it is used as optical power equalizer pair using a Fabry-Perot laser (FP-LD)
Upward signal from each ONU carries out power equalization.Due to FP-LD effective threshold current can by external optical injection and
Reduce, so the FP-LD to be worked under threshold current can be injected by using light and launch laser.Simultaneously as FP-LD
Gain competition and reset characteristic, the FP-LD to be worked under threshold current can absorb or amplify under various power levels
Incident light, so as to which most ascending power is maintained at a constant level at last.
However, such scheme has the shortcomings that the following obvious：
1st, the data-rate limitation of upward signal power equalization is less than or equal to 2.5Gb/s；And in XGPON and future
In the symmetrical TWDM-PON of 40Gb/s, it is desirable to achieve the power equalization of 10Gb/s upward signals.
2nd, in this scenario, because the wavelength of external injection signal easily drifts about, cause up after power equalization
Signal will serious distortion.
3rd, upward signal needs to amplify, to provide enough luminous powers for external optical injection signal, therefore in actual portion
Extra image intensifer is needed in administration.
The content of the invention
For problem above, the present invention proposes a kind of power for being used in the olt carry out upward signal power equalization
Balanced device and the OLT for including this power equalizer.
A kind of according to an aspect of the invention, there is provided work(for being used in the olt carry out upward signal power equalization
Rate balanced device, including：Photo-coupler, its be configured as receive the upward signal from ONU, and by its branch be Part I and
Part II；Unit is monitored and controlled, is coupled with the photo-coupler, it is configured as receiving and monitors the first of the upward signal
Partial power, and produce the control signal of the incident bias current for controlling semiconductor optical amplifier (SOA)；And should
SOA, coupled with the photo-coupler and the monitoring and control unit, it is configured as receiving the upward signal from the photo-coupler
Part II, and the control signal is received from the monitoring and control unit, adjusting its incidence according to the control signal biases
Electric current, so as to which the power of the Part II of the upward signal is adjusted into constant power level.
Using the power equalizer and OLT of the present invention, power equalization can be effectively realized in the olt.
Brief description of the drawings
, will be more preferable geographical after the description below with reference to the embodiment of the invention given by drawings below
The solution present invention, and other objects of the present invention, details, feature and advantage will become apparent.In the accompanying drawings：
Fig. 1 shows a kind of schematic diagram for the scheme for carrying out light power equalization in the olt in the prior art；
The system that Fig. 2 shows the upward signal light power equalization being used in PON system according to embodiment of the present invention
The schematic diagram of framework；
Fig. 3 shows the power for being used in the olt carry out upward signal power equalization according to embodiment of the present invention
The schematic diagram of the concrete structure of balanced device；And
Fig. 4 shows the schematic diagram of the corresponding relation between conventional SOA gain and incident bias current.
Embodiment
The preferred embodiment of the present invention is more fully described below with reference to accompanying drawings.Although the present invention is shown in accompanying drawing
Preferred embodiment, however, it is to be appreciated that may be realized in various forms the present invention without the embodiment party that should be illustrated here
Formula is limited.On the contrary, these embodiments are provided so that the present invention is more thorough and complete, and can be by the present invention's
Scope is completely communicated to those skilled in the art.
The system that Fig. 2 shows the upward signal light power equalization being used in PON system according to embodiment of the present invention
The schematic diagram of framework 200.
As shown in Figure 2, system 200 includes OLT10, one or more ONU20 (such as ONU1, ONU2 ..., ONUn),
And remote node (RN) 30.Wherein, the structure of ONU20 and remote node 30 is identical with being used in traditional PON system, therefore
Repeat no more.OLT10 uses the structure for including novel optical power equalizer 210 designed according to this invention, such as following ginseng
Examine what Fig. 3 was described in detail.
As illustrated, OLT10 includes wavelength division multiplexer (WDM) 110, power equalizer 120 and receiver 130, Yi Jiyi
A little other assemblies (these components and the implementation relation of the present invention are little, therefore herein without being described in detail).
WDM110 is configured as receiving the upward signal from multiple ONU20.Due to each ONU20 to OLT10 transmission
Distance is different, so after being transmitted by optical fiber, the power level for the upward signal that WDM110 is received is also different.In order to
To what is received there is the horizontal upward signal of different capacity to carry out light power equalization, the present invention devises a kind of novel power
Balanced device 120, for carrying out light power equalization to the upward signal received.
As illustrated, power equalizer 120 is coupled between WDM110 and receiver 130, for by from WDM110's
Upward signal is adjusted to constant power level.The concrete structure of power equalizer 120 will be retouched in detail below in reference to Fig. 3
State.
Receiver 130, for receiving the upward signal with constant power level from power equalizer 120.
Using this OLT structures, it is equal that the received upward signal with different luminous powers is incident to power first
In weighing apparatus 120, to amplify and its power be adjusted into phase same level.
Here, OLT10 structure is described by taking TDM-PON systems as an example.In TDM-PON systems, with one
All ONU related OLT launch upward signal with identical upstream wavelength, therefore only need in the olt single to what is received
The upward signal of wavelength is handled.
However, it will be understood by those skilled in the art that power allocation scheme proposed by the invention can be applied easily
In TWDM-PON systems or other have in the PON system of multiple different upstream wavelengths.In this system, such as TWDM-PON systems
In system, the multiple ONUs related from an OLT may be with different upstream wavelength (such as 4 different upstream wavelengths) transmittings
Row signal, it is therefore desirable to configure a receiving branch in the olt for each upstream wavelength.In every receiving branch, configuration one
Individual power equalizer 120, for the upward signal with identical upstream wavelength from WDM110 to be adjusted into corresponding constant
Power level.In every receiving branch, a corresponding receiver 130 is also configured, it is couple to corresponding power equalizer
120, for receiving the upward signal of the Same Wavelength with corresponding constant power level from power equalizer 120.
Using above-mentioned OLT schemes, the dynamic range of receiver 130 can be substantially reduced while effectively increasing up
The power budget of signal.
Fig. 3 shows equal for carrying out power to upward signal in OLT (such as OLT10) according to embodiment of the present invention
The schematic diagram of the concrete structure of the power equalizer 120 of weighing apparatus.
As shown in Figure 3, power equalizer 120 includes photo-coupler 122, unit 124 and semiconductor light is monitored and controlled
Amplifier (SOA) 126.
Photo-coupler 122 is configured as receiving the upward signal from ONU (ONU20 in such as Fig. 2), and is by its branch
Part I and Part II.
Preferably, the Part I for the upward signal that photo-coupler 122 is divided is far smaller than Part II.For example, light
Coupler 122 can be one 5%：95% photo-coupler, the power of the upward signal received is shunted to the first of 5% by it
Part and 95% Part II.However, art technology is arbitrarily it is appreciated that the invention is not limited in this, but can be with
Use the photo-coupler of any division proportion.
Unit 124 is monitored and controlled to couple with photo-coupler 122, it is configured as receiving and monitors photo-coupler and is divided
Upward signal Part I power, and produce the control signal of the incident bias current for controlling SOA126.
SOA126 is coupled with photo-coupler 122 and monitoring and control unit 124, and it is configured as from photo-coupler 122
The Part II of divided upward signal is received, and the control signal is received from unit 124 is monitored and controlled, according to the control
Its incident bias current of Signal Regulation processed, so as to which the power of the Part II of upward signal is adjusted into desired firm power water
It is flat.
Fig. 4 shows the schematic diagram of the corresponding relation between conventional SOA gain and incident bias current.As illustrated,
SOA gain is gradually risen with the rise of bias current, and SOA gain coefficient can be biased by changing its incidence
Electric current and be easily adjusted.
Therefore, in the present invention, unit 124 is monitored and controlled to first of the upward signal from photo-coupler 122
Point power be monitored to calculate the power of upward signal that photo-coupler 122 receives, according to the power of the upward signal
SOA126 gain coefficient is determined with the constant power level to be realized, and is biased according to SOA126 gain coefficient with incident
Relation between electric current determines the size of SOA126 incident bias current to produce the control signal (as shown in Figure 4).
Illustrate, it is assumed that the luminous power of the upward signal of entrance is A, then passes through photo-coupler 122 (such as 5%：95%
Photo-coupler) Part I after division and the power of Part II is respectively 5%A and 95%A.It is further assumed that in OLT10
The constant power level to be realized is B, then unit 124, which is monitored and controlled, to be defined as SOA126 gain coefficient GAnd determined and the gain system according to the relation between gain coefficient as shown in Figure 4 and incident bias current
Incident bias current corresponding number G is as the incident bias current for SOA126.Unit 124 is monitored and controlled to produce accordingly
Control signal to adjust SOA126 incident bias current.
As can be seen that when the luminous power of the Part I for the upward signal that monitoring and control unit 124 is monitored is higher,
SOA126 incident bias current is adjusted to a lower value, to obtain compared with low gain；On the contrary, work as monitored upward signal
Part I luminous power it is relatively low when, SOA126 incident bias current is adjusted to a high value to obtain higher increasing
Benefit.In this way, unit 124 is monitored and controlled automatically can be adjusted to appropriate by SOA126 incident bias current
Value so that the upward signal each entered obtains constant power after SOA126, so as to thoroughly disappear in OLT10
Except the serious optical power difference from different ONU, the light power equalization of upward signal is realized.
In addition, SOA126 can be enlarged over the signal of 40Gb/s data transfer rates, therefore it is fully able to be used for 10Gb/s letters
Number power equalization.
Currently, this realization can be supported in the presence of the ripe commercial SOA products with high saturation power.
In addition, in one implementation, power equalizer 120 can also include wave filter 128, and it is couple to SOA126, use
Spontaneous radiation (ASE) noise in the upward signal with constant power level for suppressing SOA126 outputs.Device after filtering
The signal of 128 processing is sent to uplink receiver (such as Rx130) to be handled.
In addition, in one implementation, power equalizer 120 can also include optical delay line 129, and it is coupled in photo-coupler
Between 122 and SOA126, the processing time of unit 124 is monitored and controlled for compensating.Optical delay line 129 can be prolonged by optical fiber
The delay devices of slow or any other forms is realized.In this way, Part II upward signal is with being monitored and controlled
Control signal caused by unit 124 keeps synchronous.
The particular advantages of the present invention are：
1st, light power equalization is realized in the olt using inexpensive component, and can be shared by all ONU, therefore realize
Cost is very low.
2nd, after light power equalization, upward signal remains in that superperformance, and existing scheme will be due to wave length shift
And cause serious distorted signals.
3rd, ONU and RN structures are identical with traditional PON system, therefore greatly reduce lower deployment cost.
4th, due to using SOA components, the present invention can support that the upward signal luminous power of 10Gb/s or more High Data Rate is equal
Weighing apparatus, and Current protocols can only support highest 2.5Gb/s data transfer rate.
5th, in addition to light power equalization, the present invention can also improve the power budget of upward signal.
It should be understood by one skilled in the art that the various exemplary logics described with reference to embodiments herein
Block, module, circuit and algorithm steps can be implemented as electronic hardware, computer software or combination.In order to understand earth's surface
Show this interchangeability between hardware and software, various exemplary part, block, module, circuit and steps are enclosed above
General description has been carried out around its function.Hardware is implemented as this function and is also implemented as software, depending on specific
Using and apply design constraint over the whole system.Those skilled in the art can be directed to every kind of application-specific, to become
Logical mode realizes described function, still, this to realize that decision-making should not be interpreted as causing a departure from the scope of this disclosure.
The above description of the present invention is used to enable any those of ordinary skill of this area to realize or using the present invention.It is right
For those of ordinary skill in the art, various modifications of the invention will be apparent from, and generality defined herein
Principle can also be applied to other deformations in the case of without deviating from the spirit and scope of the disclosed invention.Therefore, the present invention simultaneously
Example as described herein and design are not limited to, but it is consistent with the widest scope of the principle of the present invention and novel features.
Claims (7)
1. one kind is used for the power equalizer for carrying out light power equalization to upward signal in optical line terminal (OLT), including：
Photo-coupler, it is configured as receiving the upward signal from optical network unit (ONU), and is Part I by its branch
And Part II；
Unit is monitored and controlled, is coupled with the photo-coupler, it is configured as receiving and monitors the first of the upward signal
Partial luminous power, and produce the control signal of the incident bias current for controlling semiconductor optical amplifier (SOA)；And
The SOA, with the photo-coupler and the monitoring and control unit coupling, it is configured as connecing from the photo-coupler
The Part II of the upward signal is received, and the control signal is received from the monitoring and control unit, according to the control
Its incident bias current of Signal Regulation processed, so as to which the power of the Part II of the upward signal is adjusted into firm power water
It is flat,
Wherein, the monitoring and control unit calculates the upward signal according to the luminous power of the Part I of the upward signal
Power, the gain coefficient of the SOA is determined according to the power of the upward signal and the constant power level, and according to
Corresponding relation between the gain coefficient of the SOA and incident bias current determines the incident bias current for the SOA
Size is to produce the control signal.
2. power equalizer as claimed in claim 1, wherein the Part I is far smaller than Part II.
3. power equalizer as claimed in claim 2, wherein the photo-coupler includes 5%：95% photo-coupler, for inciting somebody to action
The power of the upward signal is shunted to 5% Part I and 95% Part II.
4. power equalizer as claimed in claim 1, in addition to：
Wave filter, the SOA is couple to, in the upward signal with constant power level for suppressing the SOA outputs
Spontaneous radiation (ASE) noise.
5. power equalizer as claimed in claim 1, in addition to：
Optical delay line, be coupled between the photo-coupler and the SOA, by the delay of the Part II of the upward signal with
Corresponding time processing time that unit is monitored and controlled.
6. optical line terminal (OLT) of the one kind for EPON (TDM-PON) that be time-multiplexed, including：
Wavelength division multiplexer (WDM), it is configured as receiving the upward signal from multiple optical network units (ONU), wherein described
Multiple ONU have identical upstream wavelength；
Such as the power equalizer any one of claim 1-5, it is couple to the WDM, for by from the WDM's
Upward signal is adjusted to the constant power level；And
Receiver, it is couple to the power equalizer, has constant power level with receive power equalizer output
Upward signal.
7. one kind is used for the optical line terminal (OLT) of time-division Wave division multiplexing passive optical network (TWDM-PON), including：
Wavelength division multiplexer (WDM), it is configured as receiving the upward signal from multiple ONU, wherein the multiple ONU has not
Same upstream wavelength；
Multiple power equalizers as any one of claim 1-5, it is couple to the WDM, and each power is equal
Weighing apparatus is used to the upward signal with same upstream wavelength from the WDM being adjusted to corresponding constant power level；With
And
Multiple receivers, each receiver are couple to corresponding power equalizer, to receive the tool of the power equalizer output
There is the upward signal of the Same Wavelength of constant power level.
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| Publication number | Priority date | Publication date | Assignee | Title |
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| CN106550290B (en) * | 2015-09-21 | 2020-10-02 | 南京中兴软件有限责任公司 | Passive optical network power balancing method, device, terminal, unit and system |
| US10560200B2 (en) | 2016-06-30 | 2020-02-11 | Huawei Technologies Co., Ltd. | Optical module for dynamically adjusting optical power receiving range |
| CN107666354B (en) * | 2016-07-27 | 2020-02-14 | 中国电信股份有限公司 | Power control method and system, optical line terminal and optical network unit |
| CN108574532B (en) * | 2017-03-13 | 2022-11-08 | 中兴通讯股份有限公司 | Optical signal power control method and device and optical line terminal |
| CN109547871B (en) * | 2017-09-21 | 2022-07-15 | 中兴通讯股份有限公司 | Amplification method of passive optical network uplink light and network unit |
| US11101895B2 (en) * | 2018-08-02 | 2021-08-24 | Cable Television Laboratories, Inc. | System and methods for coherent burst reception |
| CN110854660A (en) * | 2019-12-13 | 2020-02-28 | 上海长江电气设备集团有限公司 | Optical fiber amplifier |
| CN115460481A (en) * | 2021-06-09 | 2022-12-09 | 上海诺基亚贝尔股份有限公司 | Optical line terminal, method, apparatus and computer-readable storage medium for communication |
| CN113644552B (en) * | 2021-10-13 | 2022-01-18 | 北京盛镭科技有限公司 | Laser emission device and control method thereof |
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| CN1186962A (en) * | 1996-12-31 | 1998-07-08 | 大宇通信株式会社 | Gain levelling optical fiber amplifier |
| CN103401141A (en) * | 2013-08-05 | 2013-11-20 | 中国人民解放军理工大学 | Direct modulation distributed feedback semiconductor laser-based photoelectric oscillator |
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| CN1186962A (en) * | 1996-12-31 | 1998-07-08 | 大宇通信株式会社 | Gain levelling optical fiber amplifier |
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