CN101272214A - Transmission control method of wavelength division multiplexing system - Google Patents

Abstract

The invention relates to the transmission control of a wavelength division multiplexing system (WDM) in a fiber optic transmission system and proposes a transmission control method of a WDM transmission system. A channel is selected on an array wave-guide grating (AWG) at the transmitting end at intervals to carry out multi-channel signal transmission under the situation of not changing the current WDM system; the interval amount is an integer parameter m which is larger than zero, but less than one second of the amount of the channels; the channel of a receiving end AWG corresponding to the channel of the transmitting end AWG transmission signal receives the original signal transmitted by the AWG channel of the transmitting end, downloads and carries out transferring or continuously transmitting; the demodulating signal of the original signal is received in the neighboring channel of a receiving channel and the information is selected by filter or directly picked up. The transmission control method of a WDM system provided by the invention can simultaneously realize the demodulating and de-multiplexing of a nonreturn-to-zero phase position demodulating mode in the wavelength division multiplexing system without needing to carry out any alternation on the original system or adding any apparatus and is suitable for transmitting a nonreturn-to-zero (NRZ) signal and a nonreturn-to-zero differential phase shift keying(NRZ-DPSK) signal with different speeds.

Description

A kind of transfer control method of wavelength-division multiplex system

Technical field

The present invention relates to the high-speed high capacity fiber optic transmission system, relate in particular to the dense wavelength division multiplexing system of non-return-to-zero differential phase-shift keying (DPSK) modulation format in the fiber optic transmission system.

Background technology

The equation of light divides phase-shift keying (DPSK) form as a kind of Vector Modulation form, owing to can realize the transmission of constant envelope or approximately constant envelope, the nonlinear effect that can effectively suppress each type optical fiber, modulate as cross-phase, from phase modulated etc., be very suitable for the high-speed high capacity fiber optic transmission system, obtain extensive studies in recent years.Wherein, non-return-to-zero differential phase-shift keying (DPSK) modulation format (NRZ-DPSK) because the spectral width of its relative narrower is fit to be applied in the wavelength-division system (WDM) very much, has improved the transmission range and the capacity of optical fiber telecommunications system especially greatly.

In general, main transmission common non-return-to-zero modulation format (NRZ form) in the wdm system.The multichannel system of NRZ-DPSK form (wdm system) mainly is to transmit and receive end with the multichannel system difference of common format (NRZ form).Each road NRZ-DPSK signal of transmitting terminal can be realized that modulator is driven by the electric NRZ format signal through differential coding by phase-modulator (PM) or the Mach-Ze De modulator (MZM) that is operated under the push pull mode.In general, the receiving terminal of DPSK system is comparatively complicated, because its amplitude constant can not arrive its entrained information by direct detection, generally needs an asymmetric mach Zehnder interferometer (AMZI) and balance detection to demodulate primary signal and carry out balance to receive.The method is all very sensitive for ambient temperature, vibrations, polarization state etc., and is also very high to the two arm delay requirements of AMZI, also will select suitable amount of delay according to the signal rate of transmitting in the channel.Particularly in two-forty, to be accurate to several psecs especially, and need temperature control.If realize multi channel NRZ-DPSK system, receiving terminal will be quite complicated, and cost also can be very high.The method is conventional NRZ-DPSK wdm system, and its structure as shown in Figure 1.The N road flashlight of different wave length produces the multichannel dpsk signal through different dpsk signal generation modules respectively, (AWG) is multiplexed into together through multiplexer, transmit in optical fiber link through after the light amplification, at receiving terminal, demodulation multiplexer (AWG) through correspondence demultiplexes into N road signal, demodulates original data flow through different DPSK demodulation modules (AMZI) respectively again.The demodulation of each road signal of receiving terminal all will adopt AMZI and balance detector to realize in this scheme, the control of AMZI phase-shift phase also needs very accurate, the AMZI that determines can only be applicable to definite operating rate, through demodulation multiplexer and repeatedly shunt close after the road, power loss is also bigger.Generally speaking, this system is in the receiving terminal more complicated, and system cost is higher, also is difficult to control and adjusting.

Nearest 2 years, a kind of improved wdm system at the NRZ-DPSK form caused extensive interest.On the basis of conventional NRZ-DPSK wdm system, if in transmission line, add an optical circulator and periodicity fiber grating (FBG), utilize it to see through end and reflection end respectively, just can obtain being similar to two destructive interferences and the interference output port that rises mutually of AMZI, obtain the signal of two-way demodulation, and then the two paths of signals that demodulation obtains is chosen one the tunnel carry out direct detection, see accompanying drawing 2 (a); Perhaps deliver to two follow-up AWG respective channel respectively, carry out balance by the DPSK receiver module and receive, see accompanying drawing 2 (b).Because FBG is periodic, can be simultaneously the signal of each road WDM be carried out demodulation in this scheme, saved the used demodulating equipment of receiving terminal greatly, saved cost.But the shortcoming of this scheme also is significantly, need add an optical circulator and one-period FBG in the line, has increased system cost.To the scheme among Fig. 2 (a), the periodicity FBG channel spacing that is added need be selected according to the signal rate of transmitting in the circuit, has limited the flexibility of system.To the scheme among Fig. 2 (b), except having the problems referred to above, need two AWG at receiving terminal, and still need multichannel DPSK receiving system.In addition,, except will selecting, the bandwidth of its each passage is also needed special customization, generally should be taken as 60% of operating rate according to operating rate for the FBG that adds in the circuit.As the signal for 10Gb/s, the every bandwidth chahnel of FBG should be taken as 6GHz (0.048nm), and is very narrow, and processing and fabricating gets up very difficult.

The most important point is, this improvement project has been destroyed the structure of original wdm system, if introduce other device, not only improves on cost and complexity, and the NRZ-DPSK form of fixed rate can only be transmitted in the system after improving that makes, no longer is applicable to the transmission of NRZ form.

Summary of the invention

Technical problem to be solved by this invention is to overcome quite complexity of the existing receiving end signal demodulating system of NRZ-DPSK wdm system structure, the shortcoming that cost is very high, under situation about existing wdm system structure not being made any change, realize demultiplexing and demodulation to the NRZ-DPSK signal.

For solving the problems of the technologies described above, the present invention proposes a kind of transfer control method of WDM transmission system, it is characterized in that, under the situation that does not change original wdm system, multichannel signal transmission is carried out in the selector channel at interval on transmitting terminal AWG, space-number is integer parameter m, and m is greater than zero and less than 1/2nd port numbers; The passage of the receiving terminal AWG corresponding with the passage of transmitting terminal AWG transmission signals receives the primary signal that this transmitting terminal AWG channel transfer is come, download and transmit or continue and transmit, adjacent channel at this receive channel, receive the restituted signal of primary signal, choose or directly information extraction by filtering; Concrete grammar comprises:

When m=1, then,

At transmitting terminal, choose the odd chanel transmission signals of transmitting terminal AWG, the even-numbered channels free time;

At receiving terminal, the odd chanel of receiving terminal AWG is received the primary signal that the odd chanel by transmitting terminal AWG transmits, and downloads and transmit or select to continue transmission; Receive the restituted signal of its adjacent two odd-numbered channels at the even-numbered channels of receiving terminal AWG, choose a restituted signal by the receiving terminal filter in the restituted signal of these adjacent two odd-numbered channels, the filtering another one is used for follow-up direct detection and information extraction;

Perhaps;

At transmitting terminal, choose transmitting terminal AWG even-numbered channels transmission signals, the odd chanel free time;

At receiving terminal, the even-numbered channels of receiving terminal AWG is received the primary signal that the odd chanel by transmitting terminal AWG transmits, and downloads and transmit or select to continue transmission; At the odd-numbered channels of receiving terminal AWG, receive the restituted signal of its adjacent two even-numbered channels, in the restituted signal of these adjacent two even-numbered channels, choose a restituted signal by the receiving terminal filter, the filtering another one is used for follow-up direct detection and information extraction;

When m＞1, then,

At transmitting terminal, choose the channel transmission signal of the interval m of transmitting terminal AWG, the non-selected passage free time;

At receiving terminal, the passage of the receiving terminal AWG corresponding with the passage of transmitting terminal AWG transmission signals receives the primary signal that transmitting terminal AWG channel transfer is come, and downloads and transmit or select to continue transmission; In the adjacent channel that receives the primary signal channel, receive the restituted signal of primary signal, be used for follow-up direct detection and information extraction.

Theoretical foundation of the present invention is as follows:

This invention realizes the demodulation function of NRZ-DPSK signal for the filter that utilizes off resonance, but do not need to adopt other off resonance filter, but, just can utilize existing AWG to realize the function of demultiplexing and demodulation simultaneously by suitably selecting the transmission channel of existing AWG.Be equivalent to utilize the adjacency channel of AWG to realize the suitable off resonance of wavelength, and then the signal demodulation of multichannel phase modulated can be become the signal of amplitude modulation(PAM), direct detection.

For each road NRZ-DPSK signal, to be produced as example by the MZM that is operated in push pull mode, it satisfies

$E_{\mathrm{out}}\left(t\right)=E_{\mathrm{in}}\left(t\right)\·\cos (\frac{\mathrm{\π}}{V_{\mathrm{\π}}}\·\frac{V_1\left(t\right)-V_2\left(t\right)}{2})\·\exp (j\frac{\mathrm{\π}}{V_{\mathrm{\π}}}\·\frac{V_1\left(t\right)+V_2\left(t\right)}{2})---\left(1\right)$

Wherein, E _InAnd E _OutInput and output light field for modulator.V ₁And V ₂For driving the NRZ electricity NRZ signal of MZM two arms, V _πProduce π phase difference output intensity when working and become minimum needed switching voltage from maximum for half-wave voltage or for single armed.Work as V ₁And V ₂Peak value equal V _πThe time, produce the NRZ-DPSK signal.

Filter behind the NRZ-DPSK signal adopts the single order Gaussian filter, because its spectral envelope that sees through function and RZ signal is the most approaching.Its impulse response is:

$h\left(t\right)=\frac{{\mathrm{<figure-callout\; id="0"\; label="B"\; filenames="A20081004752800171.png,A20081004752800191.png"\; state="\{\{state\}\}">B</figure-callout>}}_0}{\sqrt{2\&CenterDot;\mathrm{\&pi;}}}\exp [-\frac{1}{2}{\left(B_{0}t\right)}^2]\exp \left({\mathrm{i\&omega;}}_{f}t\right)---\left(2\right)$

ω wherein _fBe the passband centre frequency of filter, ${\mathrm{<figure-callout\; id="0"\; label="B"\; filenames="A20081004752800171.png,A20081004752800191.png"\; state="\{\{state\}\}">B</figure-callout>}}_0=\mathrm{\&pi;}\&CenterDot;{\mathrm{<figure-callout\; id="3"\; label="B"\; filenames="A20081004752800141.png,A20081004752800191.png"\; state="\{\{state\}\}">B</figure-callout>}}_{3\mathrm{dB}}/\sqrt{\mathrm{<figure-callout\; id="2"\; label="ln"\; filenames="A20081004752800141.png,A20081004752800161.png"\; state="\{\{state\}\}">ln</figure-callout>}2},$ B _3dbBe filter three dB bandwidth.

Formula (1) and (2) are done the restituted signal that convolution obtains exporting:

$E_{\mathrm{de}\mathrm{mod}\mathrm{ulation}}={\&Integral;}_{-\&infin;}^{+\&infin;}{E}_{\mathrm{out}}\left(\mathrm{\&tau;}\right)h(t-\mathrm{\&tau;})\mathrm{d\&tau;}---\left(3\right)$

To (3), we simulate as shown in Figure 4 its process based on formula (1).The left side of Fig. 4 is a spectrogram, and the right is corresponding oscillogram.The top component of Fig. 4 corresponds to original NRZ-DPSK signal, lower part two figure of Fig. 4 are the restituted signal that obtain of original NRZ-DPSK signal behind filter, as seen after passing through the filter of off resonance, the carrier wave in the original NRZ-DPSK signal is partly suppressed, and high fdrequency component is extracted.This has just caused the DC component of original NRZ-DPSK partly to be suppressed, and phase hit partly is extracted out, produces pulse, has also just reached the demodulating process of phase modulated to amplitude modulation(PAM).Need to prove that this method is very big to the tolerance of filter offsets, in very large range can both reach demodulation result.

Utilize the NRZ-DPSK signal demodulation of AWG to multichannel WDM signal, the demodulation of principle and one road signal is similar.Wherein every road signal can be regarded as and utilizes the filter of off resonance to come demodulation.Because each passage of AWG is the Gaussian filter shape, each passage has just in time played the demodulation effect to the NRZ-DPSK signal of its adjacent two channel transfer.Like this, select the transmission channel of transmitting terminal AWG, just can obtain different results in the corresponding place of the AWG of receiving terminal.As shown in Figure 5, " AWG1 " indicated seeing through of a top behavior transmitting terminal AWG1 composed among the figure, and " signal " indicated middle row is the spectrum of multichannel NRZ-DPSK signal, and seeing through of the following behavior receiving terminal AWG2 that " AWG2 " is indicated composed.As seen from the figure, at transmitting terminal, the NRZ-DPSK signal is aimed at the odd chanel of AWG1, by its odd chanel transmission; Obtain the primary signal of each road NRZ-DPSK signal at the odd chanel of receiving terminal AWG2, obtain the restituted signal of the NRZ-DPSK signal of its adjacent passage in the even-numbered channels of AWG2.Solid arrow corresponds to the passage that obtains primary signal among the figure, and dotted arrow corresponds to the passage that obtains restituted signal.

On the basis that above-mentioned theory is analyzed,, utilize commercial optical fiber communication software VPI to simulate to this novel NRZ-DPSK wdm system according to the experimental provision among Fig. 3.

Four road NRZ-DPSK signals are respectively 193.1THz, 193.3THz, and 193.5THz and 193.7THz, multiplexing by one 8 passage AWG.Through after the optical fiber link transmission, at receiving terminal, also use one 8 passage AWG demultiplexing and demodulation, obtain original each road NRZ-DPSK signal at its odd chanel, obtain the restituted signal of original each road NRZ-DPSK signal in its even-numbered channels.The AWG parameter all adopts commercial AWG parameters in the simulation, and the wavelength interval is 100GHz, and it is Gaussian function that every passage sees through function, and three dB bandwidth is 55GHz.

20Gb/s is an example with the transmission of every road signal, and analog result is as follows:

A) through behind the AWG of transmitting terminal, the spectrogram after four road dpsk signals are multiplexing, as shown in Figure 6, channel spacing is 200GHz;

B) original NRZ-DPSK1 signal eye diagram and the spectrum that receives at the different passages of receiving terminal AWG, as shown in Figure 7, owing to adopt the MZM that is operated in push pull mode to produce the NRZ-DPSK signal, so can have depression at its phase hit place, as adopting PM to obtain the NRZ-DPSK signal, the original NRZ-DPSK signal that then obtains does not have this depression.But this moment is through behind the AWG, because depression also can appear in the finite bandwidth of the every passage of AWG.But have or not depression, all have phase hit, so do not influence demodulation.The left-hand component of accompanying drawing 7 (a) is the eye pattern of the original NRZ-DPSK1 signal received from receiving terminal passage 1, and right-hand component is its spectrogram.Spectrogram in the contrast accompanying drawing 6 can be found, the spectral shape unanimity, and this shows that the passage 1 of receiving terminal obtains the consistent signal of original NRZ-DPSK signal that sends with transmitting terminal, receiving terminal can be used for downloading and transmit or select to continue transmission.The left-hand component of accompanying drawing 7 (b) obtains the eye pattern of signal after for process the filters demodulate of receiving from receiving terminal passage 2, and the original NRZ-DPSK signal of transmitting terminal transmission this moment has been demodulated to the signal for amplitude modulation(PAM) as can be seen; The right-hand component of accompanying drawing 7 (b) is the spectrogram after the demodulation, and the spectrogram in the contrast accompanying drawing 6 has tangible difference.

Other each passages also can obtain corresponding primary signal and restituted signal simultaneously.Analog result is 20Gb/s herein, for 10 and 40Gb/s can obtain desired result equally, repeat no more here.

The transfer control method of a kind of wdm system provided by the invention, the demodulation that can realize the non-return-to-zero phase modulation format in the wavelength-division multiplex system simultaneously is multiplexing, need not original system is made any change, also do not need to increase any device, saved cost greatly.

Because the present invention does not need to change original system, does not need to introduce the dpsk signal demodulating equipment yet, so adopt the wavelength-division multiplex system of this invention can be applicable to the transmission of NRZ signal and NRZ-DPSK signal simultaneously.

The present invention utilizes the different passages of receiving terminal AWG, can obtain simultaneously original NRZ-DPSK signal with and restituted signal.For the primary signal that obtains, can continue transmission or download to local the forwarding to wait other operations; For the restituted signal that obtains, can utilize common receiver to carry out direct detection, obtain its contained information.Improved the flexibility of wdm system.

The present invention can also be applicable to the transmission of the NRZ and the NRZ-DPSK signal of different rates simultaneously.

Description of drawings

Below in conjunction with accompanying drawing the technical solution of the utility model is further described in detail.

Fig. 1 is the NRZ-DPSK wdm system figure of existing conventional scheme.

Fig. 2 (a) is the implementation schematic diagram of existing improved a kind of NRZ-DPSK wdm system.

Fig. 2 (b) is the implementation schematic diagram of existing improved another kind of NRZ-DPSK wdm system.

The NRZ-DPSK wdm system that Figure 3 shows that the specific embodiment of the invention is realized the structural representation that signal transmits.

Figure 4 shows that principle of the invention basis: single off resonance filter is to the schematic diagram of single channel NRZ-DPSK signal demodulation.

Figure 5 shows that the NRZ-DPSK wdm system of the specific embodiment of the invention carries out the corresponding schematic diagram of spectrum of signal transmission, demodulation.

The NRZ-DPSK wdm system that Figure 6 shows that the specific embodiment of the invention carries out the transmitting terminal of signal transmission through the multiplexed optical spectrogram behind the AWG.

The receiving terminal AWG passage 1 that the NRZ-DPSK wdm system that Fig. 7 (a) is depicted as the specific embodiment of the invention carries out the signal transmission receives the eye pattern and the spectrum of signal.

The receiving terminal AWG passage 2 that the NRZ-DPSK wdm system that Fig. 7 (b) is depicted as the specific embodiment of the invention carries out the signal transmission receives the eye pattern and the spectrum of signal.

Embodiment

As shown in Figure 3, be emission, transmission and the reception schematic diagram of novel NRZ-DPSK wdm system.Describe operation principle, implementation condition and the step of each several part below in detail.

Because key of the present invention is the passage of ingenious selection transmitting terminal and receiving terminal AWG, realizes multiple function.So at first the channel selecting principle to transmitting terminal and receiving terminal AWG is explained and illustrated:

According to the different interval (being channel spacing) of the wavelength (perhaps frequency) of adjacent channel institute transmitting optical signal, International Telecommunication Union has carried out detailed regulation to wavelength-division multiplex system (WDM) system.Wdm system is divided into dense wavelength division multiplexing system (DWDM) and coarse wavelength division multiplexing systems (CWDM).

Wherein the channel spacing of dwdm system can be 12.5GHz, 25GHz, 50GHz, 100GHz, 200GHz, 300GHz, 400GHz or the like; And the channel spacing of CWDM system is 2500GHz.Need to prove that ITU just stipulates channel spacing, and to the signal rate transmitted in each channel regulation not.People need decide according to the signal rate of required transmission and choose which kind of DWDM channel spacing, and the signal rate of transmitting in each channel is high more, and then channel spacing will be big more.In general, if want the signal of transmission 40Gb/s in each channel, then channel spacing must be greater than 40*2=80GHz.So for the signal of 40Gb/s, can select the 100GHz of DWDM, 200GHz, channel spacings such as 300GHz, and CWDM channel spacing.And can be applicable to 40Gb/s signal channel transmitted at interval, can the down compatible more transmission of low-rate signal, promptly be applicable to the channel spacing of 40Gb/s signal, also be applicable to 20Gb/s, 10Gb/s or the like.

In the concrete real-time mode of the present invention, 10Gb/s is an example to the high speed signal of 40Gb/s with transmission, and therefore following the discussion meets 100GHz that ITU stipulates and above channel spacing (comprising CWDM).

For how realizing different channel spacings, be example with the commercial AWG of a 100GHz channel spacing, can realize with the following method:

1) when each passage of this AWG all during transmission signals, this moment, channel spacing was 100GHz; 2) when this AWG has only odd number or even-numbered channels transmission signals, other passage free time, this moment, channel spacing was 200GHz; 3) when 1,4,7,10 channel transmission signals such as grade of this AWG, other passage free time, this moment, channel spacing was 300GHz.Other channel spacing by that analogy.

The present invention utilizes certain idle channel of AWG, and the signal in its two adjacent passages is carried out demodulation, comprises following several situation:

A) if adjacent two passages of a certain passage all have the signal transmission, then can obtain the restituted signal of these two signals simultaneously, but the filter in the follow-up receiver can well separate these two restituted signals, chooses one of them at this passage.Situation 1 below this kind situation correspondence).

B) if adjacent two passages of a certain passage have only a passage that the signal transmission is arranged, another passage free time, then obtain the restituted signal of this signal, the situation 2 below this kind situation correspondence) at this passage.

C) if AWG does not have idle channel, promptly its each passage all has signal transmission, then can utilize other ways, produces some idle channels, the situation 3 below this kind situation correspondence).

The passage of supposing the AWG (being called AWG1) of transmitting terminal 100GHz channel spacing is followed successively by I1, I2, and I3, I4 etc., when

1) channel spacing is 200GHz (annotate: the signal rate of every channel transfer can be 10Gb/s, and 20Gb/s and 40Gb/s are together following)

At this moment, choose the I1 of AWG1, I3, odd chanel transmission signals such as I5, the even-numbered channels free time (otherwise, also can choose I2, I4, the transmission of even-numbered channels such as I6, odd chanel free time).Like this, locate at the AWG (being called AWG2) of the same specification of receiving terminal, I1, I3, odd chanels such as I5 just can obtain the I1 by AWG1, I3, the primary signal that channel transfer such as I5 are come.And at the I2 of AWG2, I4, even-numbered channels such as I6 do not transmit though have signal in AWG1 place respective channel, can obtain the restituted signal (principle later analysis) of its adjacent channel.For example, at the I2 of AWG2 passage, can obtain the restituted signal of I1 passage and I3 channel simultaneously; At the I4 of AWG passage, can obtain the restituted signal of I3 passage and I5 passage simultaneously.It should be noted that the restituted signal that can obtain its adjacent two odd chanels in each even-numbered channels, but the general filter in receiver can be chosen one of them restituted signal, the filtering another one.

2) channel spacing is more than 300GHz reaches

With the 300GHz channel spacing is example, chooses I1, I4, channel transmission signals such as I7, other channel idle.Like this, can obtain the restituted signal of I1 passage at the I2 of AWG2 passage; I3 and I5 passage can obtain the restituted signal of I4 passage.And corresponding passage is had to the restituted signal of an adjacent passage, can be as 1) in obtain two restituted signals.In such cases, image intensifer in the receiver and filter can further be saved, and this system can also be used in the WDM EPON (PON).

400GHz, 500GHz, 600GHz etc. comprise CWDM, situation all 300GHz is similar, repeats no more.

3) channel spacing is 100GHz

This moment the situation more complicated.Each passage of AWG1 is transmission signals all, but at first utilizes an interleaver (interleaver) that all channels are divided into two groups at receiving terminal, one group of odd-numbered channels, one group of even-numbered channels.Then, respectively to the situation of odd number group and even number set, with situation 1) identical.

Below again in conjunction with Fig. 3, the situation of the 200GHz of last surface analysis is specifically described

(1) transmitting terminal

Transmitting terminal is the same with traditional wdm system, does not need to make any change.Each the road NRZ-DPSK signal that meets ITU WDM provision wavelengths is by AWG multiplexing (perhaps the continuous light of each road different wave length is after AWG1 is multiplexing, again by a MZM or PM modulation).But be with the conventional system difference, pass one road signal every a channel herein, promptly meet the 100GHz AWG at interval of ITU regulation, transmission 200GHz signal at interval.As shown in FIG., the transmission of the odd chanel of AWG1 meets the wavelength of ITU regulation, the even-numbered channels free time, also can be used for other purposes.It should be noted that the flexibility that has kept wdm system herein, the signal rate of transmitting on every paths is variable, as 10Gb/s, and 20Gb/s or 40Gb/s or the like.And owing to do not introduce other devices, this invention also is applicable to the wdm system of NRZ form.

(2) receiving terminal

Receiving terminal is also without any need for change.The AWG of receiving terminal is the same with the parameter of transmitting terminal, but its each passage all uses.Shown in AWG2 among the figure, the wavelength and the AWG1 of its each passage are in full accord, meet the regulation of ITU.The odd chanel of AWG2 can receive the NRZ-DPSK signal of original each passage, can be used for downloading primary signal and transmit or select to continue transmission, can obtain the signal after first passage (I1) transmission of AWG1 as the first passage (I1) of AWG2; Meanwhile, the even-numbered channels of AWG2 can obtain the restituted signal of the dpsk signal of its adjacent two odd chanels, second channel (I2) as AWG2 can obtain the first passage (I1) of AWG1 and the restituted signal of the middle NRZ-DPSK signal that transmits of third channel (I3), is used for follow-up direct detection and information extraction.

But need to prove that each even-numbered channels of AWG2 can obtain the restituted signal of original two paths of signals, must extract wherein and one the tunnel survey, and eliminate crosstalking of another road as far as possible.Utilize the follow-up receiver of this passage to reach this purpose this moment, and do not need other processing.General receiver (receiver) is all by preamplifier (EDFA), and filter (filter) and photodetector (PD) are formed, shown in dashed rectangle among Fig. 3.The effect of its median filter is the noise that filtering is introduced by EDFA, and its centre wavelength is the wavelength of optical signal that is received.Simultaneously, this filter also can be used for choosing in the two-way wavelength one road wavelength of required reception and surveys.As second channel (I2), though there is the restituted signal (λ of two wavelength in it for AWG2 ₁And λ ₂), but the filter center wavelength in the receiver is λ herein ₁, just can filtering λ ₂, make PD receive by λ ₁The information that demodulation obtains.

If the AWG1 place, incoming signal is not 200GHz at interval, but bigger, as 300GHz, does not just have this cross-interference issue.This moment, the incident port of AWG1 was 1,4,7,10 etc.First passage (I1) signal with AWG1 is an example, this moment, the first passage at AWG2 still obtained original incident NRZ-DPSK signal, its second channel can obtain the restituted signal of this NRZ-DPSK signal, can not obtain the restituted signal of the I4 of AWG1, does not just have cross-interference issue.

AWG2 just can play double action among the present invention: 1. demultiplexing.Each road signal after can be with AWG1 multiplexing is demultiplexed on the corresponding ITU passage, continues transmission or transmits the flexibility that has kept wdm system; 2. demodulation.Cooperate follow-up regular tenacity modulated signal receiver (not needing DPSK receiver or particular device), just can be demodulated to corresponding strength modulation signal and direct detection by multiplexing each next road NRZ-DPSK signal of AWG1.These two kinds of functions that it is emphasized that AWG2 exist simultaneously, realize simultaneously, are realized by its odd chanel and even-numbered channels respectively.This just makes AWG2 can not only be used in receiving terminal, equally also can use in the circuit transmission or on the network node, has promoted the flexibility of this NRZ-DPSK wdm system greatly.

It should be noted last that, above embodiment is only unrestricted in order to technical scheme of the present invention to be described, although the present invention is had been described in detail with reference to preferred embodiment, those of ordinary skill in the art is to be understood that, can make amendment or be equal to replacement technical scheme of the present invention, and not breaking away from the spirit and scope of technical solution of the present invention, it all should be encompassed in the middle of the claim scope of the present invention.

Claims (1)

1, a kind of transfer control method of wavelength-division multiplex system, it is characterized in that under the situation that does not change original wdm system, multichannel signal transmission is carried out in the selector channel at interval on transmitting terminal AWG, space-number is integer parameter m, and m is greater than zero and less than 1/2nd port numbers; The passage of the receiving terminal AWG corresponding with the passage of transmitting terminal AWG transmission signals receives the primary signal that this transmitting terminal AWG channel transfer is come, download and transmit or continue and transmit, adjacent channel at this receive channel, receive the restituted signal of primary signal, choose or directly information extraction by filtering; Concrete grammar comprises:

When m=1, then,

At transmitting terminal, choose the odd chanel transmission signals of transmitting terminal AWG, the even-numbered channels free time;

At receiving terminal, the odd chanel of receiving terminal AWG is received the primary signal that the odd chanel by transmitting terminal AWG transmits, and downloads and transmit or select to continue transmission; Receive the restituted signal of its adjacent two odd-numbered channels at the even-numbered channels of receiving terminal AWG, choose a restituted signal by the receiving terminal filter in the restituted signal of these adjacent two odd-numbered channels, the filtering another one is used for follow-up direct detection and information extraction;

Perhaps;

At transmitting terminal, choose transmitting terminal AWG even-numbered channels transmission signals, the odd chanel free time;

At receiving terminal, the even-numbered channels of receiving terminal AWG is received the primary signal that the odd chanel by transmitting terminal AWG transmits, and downloads and transmit or select to continue transmission; At the odd-numbered channels of receiving terminal AWG, receive the restituted signal of its adjacent two even-numbered channels, in the restituted signal of these adjacent two even-numbered channels, choose a restituted signal by the receiving terminal filter, the filtering another one is used for follow-up direct detection and information extraction;

When m＞1, then,

At transmitting terminal, choose the channel transmission signal of the interval m of transmitting terminal AWG, the non-selected passage free time;

At receiving terminal, the passage of the receiving terminal AWG corresponding with the passage of transmitting terminal AWG transmission signals receives the primary signal that transmitting terminal AWG channel transfer is come, and downloads and transmit or select to continue transmission; In the adjacent channel that receives the primary signal channel, receive the restituted signal of primary signal, be used for follow-up direct detection and information extraction.

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