CN105515679B - Relevant ONU based on dual output EAM and its method for realizing single fiber bi-directional transmission - Google Patents
Relevant ONU based on dual output EAM and its method for realizing single fiber bi-directional transmission Download PDFInfo
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- CN105515679B CN105515679B CN201510870022.8A CN201510870022A CN105515679B CN 105515679 B CN105515679 B CN 105515679B CN 201510870022 A CN201510870022 A CN 201510870022A CN 105515679 B CN105515679 B CN 105515679B
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B10/00—Transmission systems employing electromagnetic waves other than radio-waves, e.g. infrared, visible or ultraviolet light, or employing corpuscular radiation, e.g. quantum communication
- H04B10/60—Receivers
- H04B10/61—Coherent receivers
- H04B10/64—Heterodyne, i.e. coherent receivers where, after the opto-electronic conversion, an electrical signal at an intermediate frequency [fIF] is obtained
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B10/00—Transmission systems employing electromagnetic waves other than radio-waves, e.g. infrared, visible or ultraviolet light, or employing corpuscular radiation, e.g. quantum communication
- H04B10/27—Arrangements for networking
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B10/00—Transmission systems employing electromagnetic waves other than radio-waves, e.g. infrared, visible or ultraviolet light, or employing corpuscular radiation, e.g. quantum communication
- H04B10/60—Receivers
- H04B10/61—Coherent receivers
- H04B10/615—Arrangements affecting the optical part of the receiver
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04Q—SELECTING
- H04Q11/00—Selecting arrangements for multiplex systems
- H04Q11/0001—Selecting arrangements for multiplex systems using optical switching
- H04Q11/0062—Network aspects
- H04Q11/0067—Provisions for optical access or distribution networks, e.g. Gigabit Ethernet Passive Optical Network (GE-PON), ATM-based Passive Optical Network (A-PON), PON-Ring
Abstract
The invention discloses a kind of relevant ONU based on dual output EAM and its method for realizing single fiber bi-directional transmission, this method to include：Upward signal carries out intensity modulated by dual output electroabsorption modulator, is exported through its first delivery outlet；The local concussion light source LO of second delivery outlet output；Downstream signal is transmitted to coherent receiver through optical fiber；Coherent receiver carries out relevant heterodyne detection to downstream signal using local concussion light source LO；Digital signal processing chip carries out numeral to the I roads signal obtained by relevant heterodyne detection and Q roads signal as coherent digital envelope detected algorithm and recovers processing processing.The present invention can meet up modulation and downlink reception simultaneously by dual output electroabsorption modulator, digital recovery processing is carried out by coherent digital envelope detected algorithm, it is larger with influence of the frequency jitter to signal quality greatly to overcome dual output electroabsorption modulator Light source line width, dual output electroabsorption modulator cost is cheap, size is small, low in energy consumption, reduces relevant EPON construction cost.
Description
Technical field
The present invention relates to relevant EPON field, and in particular to based on dual output EAM (Electro Absorption
Modulator, electroabsorption modulator) relevant ONU (Optical Network Unit, optical network unit) and its realize single fiber
The method of transmitted in both directions.
Background technology
Coherent light communication mainly utilizes coherent modulation and heterodyne Detection Technique, has high sensitivity, repeater span length, selection
Property good and message capacity it is big the advantages that, based on relevant detection (demodulation mechanism of signal, it is relevant to detect more compared with directly detecting
Be readily available big signal to noise ratio, recoverable signal kinds are more, and frequency selectivity is preferable) passive optical network be
Relevant passive optical network, has the advantages that power budget is big, access rate is high and passage is flexibly adjustable, and based on relevant
The i.e. relevant ONU of the ONU of detection, as the important component of relevant passive optical network, its cost is that influence is relevant passive
The key factor of optical network system.
At present, the passive optical network that is concerned with requires single fiber bi-directional transmission, i.e., to be realized simultaneously in same root optical fiber up
With the transmission of downstream signal, and traditional relevant ONU is up is connected to central office, lower behavior personal user by GEPON ports
Or SOHO user provides 1 tunnel gigabit Etherenet network interfaces, it can not realize that single fiber bi-directional transmits, further, since narrow linewidth single longitudinal mode
Costly, for cost consideration, be concerned with the price of optical fiber laser (can ensure that laser has fabulous coherence) nothing
Source optical network system is difficult to receive expensive narrow linewidth laser and external modulation technology.
In view of this, it is necessary to carry out structure improvement to existing relevant ONU, meet the needs of single fiber bi-directional transmission, so as to
Reduce the construction cost of relevant EPON.
The content of the invention
The technical problems to be solved by the invention are the problem of existing relevant ONU can not realize single fiber bi-directional transmission.
In order to solve the above-mentioned technical problem, the technical solution adopted in the present invention is to provide a kind of based on dual output EAM's
Relevant ONU, including coherent receiver, dual output electroabsorption modulator and digital signal processing chip,
After upward signal carries out intensity modulated by the dual output electroabsorption modulator, exported through its first delivery outlet, together
When, its second delivery outlet exports the local concussion light source LO for the heterodyne detection that is concerned with；
Downstream signal is transmitted to the coherent receiver, and the coherent receiver is using the local light source LO that shakes to institute
State downstream signal and carry out relevant heterodyne detection；
The digital signal processing chip is believed the I roads obtained by heterodyne detection of being concerned with as coherent digital envelope detected algorithm
Number and Q roads signals carry out digital recovery processing.
In the above-mentioned technical solutions, the dual output electroabsorption modulator includes DBR active areas, Part I transmission DBR
Speculum, electro-absorption modulation area, electrode, the first lens, Part II transmission DBR speculums and the second lens,
The DBR active areas, which excite, produces continuous light wave, and a portion light wave reflects through Part II transmission DBR
Mirror and second lens focus, as the local concussion light source LO outputs；
Another part light wave is exported to the electro-absorption modulation area, modulation electricity through Part I transmission DBR speculums
Flow through the electrode to be loaded on light carrier, most exported afterwards through first lens focus as the upward signal.
In the above-mentioned technical solutions, the digital signal processing chip combines I roads signal and Q roads signal,
(I+j × Q) complex signal is formed, (I+j × Q) complex signal can be expressed as：I+j × Q=A (n) × exp (2 π j Δs fn
+θ(n))；Wherein, A (n) represents strength signal, and the A (n) can be by obtaining to (I+j × Q) the complex signal modulus, institute
Stating A (n) can be to recover transmission information after decision-making is adjudicated；Δ f represents the frequency-splitting of relevant heterodyne detection, and θ (n) is represented
Light source line width, j represent -1 square root, and n represents sampled point index.
In the above-mentioned technical solutions, the wavelength of the upward signal is equal with the wavelength of the local concussion light source LO.
In the above-mentioned technical solutions, the frequency-splitting between the local concussion light source LO and the downstream signal is more than letter
Number bandwidth.
Present invention also offers a kind of method that relevant ONU based on dual output EAM realizes single fiber bi-directional transmission, including with
Lower step：
After upward signal carries out intensity modulated by dual output electroabsorption modulator, through the dual output electroabsorption modulator
First delivery outlet exports；
Second delivery outlet of the dual output electroabsorption modulator exports the local concussion light source for the heterodyne detection that is concerned with
LO；
Downstream signal is transmitted to coherent receiver through optical fiber；
The coherent receiver carries out relevant heterodyne detection to the downstream signal using the local light source LO that shakes, and
By obtained I roads signal and Q roads signal output to digital signal processing chip；
The digital signal processing chip is believed I roads signal and the Q roads by coherent digital envelope detected algorithm
Number handled, recover the downstream signal.
In the above-mentioned technical solutions, the dual output electroabsorption modulator includes DBR active areas, Part I transmission DBR
Speculum, electro-absorption modulation area, electrode, the first lens, Part II transmission DBR speculums and the second lens,
The DBR active areas, which excite, produces continuous light wave, and a portion light wave reflects through Part II transmission DBR
Mirror and second lens focus, as the local concussion light source LO outputs；
Another part light wave is exported to the electro-absorption modulation area, modulation electricity through Part I transmission DBR speculums
Flow through the electrode to be loaded on light carrier, most exported afterwards through first lens focus as the upward signal.
In the above-mentioned technical solutions, the coherent digital envelope detected algorithm concretely comprises the following steps：
The digital signal processing chip combines I roads signal and Q roads signal, forms (I+j × Q) plural number letter
Number, (I+j × Q) complex signal can be expressed as：I+j × Q=A (n) × exp (2 π j Δ fn+ θ (n))；Wherein, A (n) tables
Show strength signal, Δ f represents the frequency-splitting of relevant heterodyne detection, and θ (n) represents Light source line width, and j represents -1 square root, n tables
Show that sampled point indexes, the A (n) is obtained to (I+j × Q) the complex signal modulus, the A (n) is after decision-making is adjudicated
To recover transmission information.
In the above-mentioned technical solutions, the wavelength of the upward signal is equal with the wavelength of the local concussion light source LO.
In the above-mentioned technical solutions, the frequency-splitting between the local concussion light source LO and the downstream signal is more than letter
Number bandwidth.
Relevant ONU provided by the invention based on dual output EAM and its method for realizing single fiber bi-directional transmission, pass through lose-lose
Up modulation and downlink reception can be met simultaneously by going out electroabsorption modulator, meanwhile, by coherent digital envelope detected algorithm under
Row signal carries out digital recovery processing, and it is larger with frequency jitter pair greatly to overcome dual output electroabsorption modulator Light source line width
The influence of signal quality, the cost of dual output electroabsorption modulator is cheap, size is small, low in energy consumption, reduces relevant passive optical network
The construction cost of network.
Brief description of the drawings
Fig. 1 is the structured flowchart of the relevant ONU provided in an embodiment of the present invention based on dual output EAM；
Fig. 2 is the fundamental diagram of the relevant ONU provided in an embodiment of the present invention based on dual output EAM；
Fig. 3 is the schematic diagram of dual output electroabsorption modulator provided in an embodiment of the present invention；
Fig. 4 is for digital signal processing chip provided in an embodiment of the present invention by coherent digital envelope detected algorithm to descending
Signal carries out the flow chart of digital recovery；
Fig. 5 is the side that a kind of relevant ONU based on dual output EAM provided in an embodiment of the present invention realizes single fiber bi-directional transmission
Method flow chart.
Embodiment
The present invention is described in detail with reference to specification drawings and specific embodiments.
The embodiments of the invention provide a kind of relevant ONU based on dual output EAM, as shown in figure 1, being inhaled including dual output electricity
Modulator 10, coherent receiver 20 and digital signal processing chip 30 are received,
After upward signal carries out intensity modulated by dual output electroabsorption modulator 10, through dual output electroabsorption modulator 10
First delivery outlet exports, meanwhile, the second delivery outlet of dual output electroabsorption modulator 10 exports the sheet for the heterodyne detection that is concerned with
Ground concussion light source LO；
Downstream signal transmits to coherent receiver 20, coherent receiver 20 to enter downstream signal using local concussion light source LO
The relevant heterodyne detection of row；
Digital signal processing chip 30 is as coherent digital envelope detected algorithm to the I roads signal obtained by relevant heterodyne detection
Digital recovery processing is carried out with Q roads signal.
As shown in Fig. 2 it is the fundamental diagram of the relevant ONU based on dual output EAM, the wavelength of upward signal and this earthquake
Swing that light source LO wavelength is equal, the local frequency-splitting shaken between light source LO and downstream signal is more than signal bandwidth, therefore can
To be effectively prevented from upward signal and the downstream signal caused Ruili backscattering (Rayleigh in transmitting procedure
Backscattering) disturb.
As shown in figure 3, being the schematic diagram of dual output electroabsorption modulator 10, dual output electroabsorption modulator 10 includes：DBR
Active area 101, Part I transmission DBR speculums 102, electro-absorption modulation area 103, electrode 104,105, second, the first lens
Divide transmission DBR speculums 106 and the second lens 107.DBR active areas 101, which excite, produces continuous light wave, a portion light wave
The continuous light wave for forming the second delivery outlet is focused on through Part II transmission DBR speculums 106, the second lens 107, is used as this earthquake
Swing light source LO outputs；Another part light wave transmits DBR speculums 102 through Part I and exported to electro-absorption modulation area 103, modulation
Electric current is loaded on light carrier through electrode 104, is most focused on the modulated light wave for forming the first delivery outlet through the first lens 105 afterwards, is made
Exported for upward signal.
As shown in figure 4, downstream signal is carried out by coherent digital envelope detected algorithm for digital signal processing chip 30
The flow chart that numeral is recovered, digital signal processing chip 30 combine I roads signal and Q roads signal, form (I+j × Q) plural number letter
Number, (I+j × Q) complex signal can be expressed as：I+j × Q=A (n) × exp (2 π j Δ fn+ θ (n))；Wherein, A (n) represents strong
Signal is spent, A (n) can be by being obtained to (I+j × Q) complex signal modulus, and A (n) can be sent after decision-making is adjudicated to recover
Information；Δ f represents the frequency-splitting of relevant heterodyne detection, and θ (n) represents Light source line width, and j represents -1 square root, and n represents sampling
Point index.By coherent digital envelope detected algorithm, frequency-splitting and line width information that (I+j × Q) complex signal is included
Remove during modulus, therefore this method has very strong robustness to frequency disturbance and high line width.
The embodiment of the present invention additionally provides a kind of method that relevant ONU based on dual output EAM realizes single fiber bi-directional transmission,
As shown in figure 5, comprise the following steps：
After step 101, upward signal carry out intensity modulated by dual output electroabsorption modulator, through dual output electro-absorption modulation
The first delivery outlet output of device.
Step 102, the second delivery outlet of dual output electroabsorption modulator export the local concussion for the heterodyne detection that is concerned with
Light source LO.
Step 103, downstream signal are transmitted to coherent receiver through optical fiber.
Step 104, coherent receiver carry out relevant heterodyne to downstream signal using local concussion light source LO and detected, and will
The I roads signal that arrives and Q roads signal output are to digital signal processing chip.
Step 105, digital signal processing chip are entered by coherent digital envelope detected algorithm to I roads signal and Q roads signal
Row processing, recovers downstream signal.
The present invention is not limited to above-mentioned preferred forms, and anyone should learn that the knot made under the enlightenment of the present invention
Structure changes, and the technical schemes that are same or similar to the present invention, each falls within protection scope of the present invention.
Claims (8)
1. the relevant ONU based on dual output EAM, including coherent receiver and digital signal processing chip, it is characterised in that also wrap
Dual output electroabsorption modulator is included,
After upward signal carries out intensity modulated by the dual output electroabsorption modulator, exported through its first delivery outlet, meanwhile, its
Second delivery outlet exports the local concussion light source LO for the heterodyne detection that is concerned with；
Downstream signal is transmitted to the coherent receiver, and the coherent receiver is using the local light source LO that shakes under described
Row signal carries out relevant heterodyne detection；
The digital signal processing chip as coherent digital envelope detected algorithm to be concerned with heterodyne detection gained I roads signal with
Q roads signal carries out digital recovery processing；
The dual output electroabsorption modulator includes DBR active areas, Part I transmission DBR speculums, electro-absorption modulation area, electricity
Pole, the first lens, Part II transmission DBR speculums and the second lens,
The DBR active areas, which excite, produces continuous light wave, a portion light wave through the Part II transmit DBR speculums and
Second lens focus forms the continuous light wave of the second delivery outlet, as the local concussion light source LO outputs；
Another part light wave is exported to the electro-absorption modulation area, modulation electric current warp through Part I transmission DBR speculums
The electrode is loaded on light carrier, the modulated light wave of the first delivery outlet is most formed through first lens focus afterwards, as institute
State upward signal output.
2. the relevant ONU based on dual output EAM as claimed in claim 1, it is characterised in that the digital signal processing chip
I roads signal and Q roads signal are combined, form (I+j × Q) complex signal, (I+j × Q) complex signal can be with
It is expressed as：I+j × Q=A (n) × exp (2 π j Δ fn+ θ (n))；Wherein, A (n) represents strength signal, and the A (n) can be by right
(I+j × Q) the complex signal modulus obtains, and the A (n) can be to recover transmission information after decision-making is adjudicated；Δ f is represented
The frequency-splitting of relevant heterodyne detection, θ (n) represent Light source line width, and j represents -1 square root, and n represents sampled point index.
3. the relevant ONU based on dual output EAM as claimed in claim 1, it is characterised in that the wavelength of the upward signal with
The wavelength of the local concussion light source LO is equal.
4. the relevant ONU based on dual output EAM as claimed in claim 1, it is characterised in that the local concussion light source LO with
Frequency-splitting between the downstream signal is more than signal bandwidth.
5. a kind of method that relevant ONU based on dual output EAM realizes single fiber bi-directional transmission, it is characterised in that including following step
Suddenly：
After upward signal carries out intensity modulated by dual output electroabsorption modulator, first through the dual output electroabsorption modulator
Delivery outlet exports；
Second delivery outlet of the dual output electroabsorption modulator exports the local concussion light source LO for the heterodyne detection that is concerned with；
Downstream signal is transmitted to coherent receiver through optical fiber；
The coherent receiver carries out relevant heterodyne to the downstream signal using the local concussion light source LO and detected, and will
The I roads signal that arrives and Q roads signal output are to digital signal processing chip；
The digital signal processing chip is entered by coherent digital envelope detected algorithm to I roads signal and Q roads signal
Row processing, recovers the downstream signal；
The dual output electroabsorption modulator includes DBR active areas, Part I transmission DBR speculums, electro-absorption modulation area, electricity
Pole, the first lens, Part II transmission DBR speculums and the second lens,
The DBR active areas, which excite, produces continuous light wave, a portion light wave through the Part II transmit DBR speculums and
Second lens focus forms the continuous light wave of the second delivery outlet, as the local concussion light source LO outputs；
Another part light wave is exported to the electro-absorption modulation area, modulation electric current warp through Part I transmission DBR speculums
The electrode is loaded on light carrier, the modulated light wave of the first delivery outlet is most formed through first lens focus afterwards, as institute
State upward signal output.
6. method as claimed in claim 5, it is characterised in that the coherent digital envelope detected algorithm concretely comprises the following steps：
The digital signal processing chip combines I roads signal and Q roads signal, forms (I+j × Q) complex signal,
(I+j × Q) complex signal can be expressed as：I+j × Q=A (n) × exp (2 π j Δ fn+ θ (n))；Wherein, A (n) is represented
Strength signal, Δ f represent the frequency-splitting of relevant heterodyne detection, and θ (n) represents Light source line width, and j represents -1 square root, and n is represented
Sampled point indexes, and obtains the A (n) to (I+j × Q) the complex signal modulus, and the A (n) can be with after decision-making is adjudicated
Recover transmission information.
7. method as claimed in claim 5, it is characterised in that the wavelength of the upward signal and the local concussion light source LO
Wavelength it is equal.
8. method as claimed in claim 5, it is characterised in that between the local concussion light source LO and the downstream signal
Frequency-splitting is more than signal bandwidth.
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| CN201510870022.8A CN105515679B (en) | 2015-12-01 | 2015-12-01 | Relevant ONU based on dual output EAM and its method for realizing single fiber bi-directional transmission |
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| CN103095623B (en) * | 2011-10-27 | 2015-07-01 | 武汉邮电科学研究院 | Modulating device, modulating method, demodulating device and demodulating method |
| CN104010233B (en) * | 2014-05-15 | 2018-02-09 | 北京大学 | A kind of relevant detection EPON of palarization multiplexing based on RSOA |
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Address after: 430074, No. 88, postal academy road, Hongshan District, Hubei, Wuhan Patentee after: Wuhan post and Telecommunications Science Research Institute Co., Ltd. Address before: 430074, No. 88, postal academy road, Hongshan District, Hubei, Wuhan Patentee before: Wuhan Inst. of Post & Telecom Science |