Millimeter wave WDM-ROF (Wavelength Division Multiplexing-Radio Over Fiber) system and method based on supercontinuum

03-11-2010 дата публикации
Номер:
CN0101877614A
Контакты:
Номер заявки: 20-10-20107965
Дата заявки: 24-06-2010

[1]

Technical Field

[2]

The present invention relates to communication technology, in particular relates to a millimeter wave super-continuous spectrum-based wavelength division multiplexing-light system and method for wireless composite (WDM-ROF).

[3]

Background Art

[4]

In recent years the construction of the optical fiber communications technology has been the large backbone network distributed in the world, a large capacity of information to realize long-distance transmission. In order to meet the mobility, flexibility, large capacity and the requirements of the low-loss signal transmission, a wireless access technology and optical fiber access technology combined with the model access technology-optical wireless composite (  Fiber   Over Radio, ROF) technology is proposed. Technology is ROF to optical fiber as a transmission medium, light wave as the carrier wave, modulation wave of microwave as a kind of technology of information transmission, that is transmitted on the optical fiber with information of the radio-frequency signal, and to integrate such a radio-frequency signal through the antenna radiation in the form of propagation of the technology to the user.

[5]

Based on existing ROF optical wireless communication system includes: central station (  Station Center, CS), the base station (  Station Base, BS) and links the two the optical fiber link. Wherein the optical fiber link includes a base station to the central station uplink optical link and the central station to the base station downlink optical link. The air channel as the radio signal frequency attenuation characteristic, in order to meet the needs of the coverage area, the system in each of the plurality of antennas BS need to be connected, this will increase the load of the system and base station maintenance cost; therefore, existing ground in ROF in the optical wireless communication system, a large concentration of CS data processing, control and management, wireless carrier and modulation function; BS only need to be provided with an optical/electric signal conversion, and a simple amplifying RF signal transmitting/receiving function of the wireless signal. Based on existing ROF in the optical wireless communication system, the optical fiber link a certain time only on an optic fiber to transmit a channel signal, the optical channel resource waste, limiting the amount of information transmitted; in addition, taking into account the radio frequency signal bandwidth and to bear the weight of the attenuation of the air channel, the millimeter-wave range should be selected radio frequency signal as a subcarrier, millimeter-wave range of the frequency range of the radio frequency signal 40GHz to 100GHz between, but because of the technological process, can be produced with lower costs 60GHz the above high-frequency radio frequency signal, also cannot be truly realize millimeter wave as of the wireless transmission mode of the sub-carriers.

[6]

In order to solve existing ROF-based optical wireless communication system the problem of channel resources wasted light, WDM-ROF system emerged. WDM-ROF system that is based on the existing optical ROF on the basis of a wireless communication system, the wavelength division multiplexing optical fiber link (  Multiplexing   Division Wavelength, WDM) technology, at the same time and CS BS formed between the plurality of channels, increase the capacity of the signal channel, the amount of information of the transmission is increased, based on existing ROF the optical wireless communication system the problem of channel resources wasted light.

[7]

Figure 1 is a structure diagram of the existing WDM-ROF system. This combination of Figure 1, the existing WDM-ROF a description of the structure of the system, as follows:

[8]

Existing WDM-ROF system comprises: a transmitting module 10, link module 11 and a receiving module 12.

[9]

Sending module 10 is used for producing the optical signal, the generated information-carrying high-speed data signal to the optical signals, and the high-speed data signal information-carrying optical signal of phase and intensity modulation, output the modulated light signal to link module 11. Wherein sending module 10 including M light source and with each a light source connected with the modulation unit M, wherein the laser light source 100, each of the modulation unit includes a phase modulator 101, a signal driver 102, intensity modulator 103 and radio source 104. Laser 100 for generating narrow-spectrum light signal, and each two laser 100 is greater than the interval of the center wavelength of a required is equal to the interval of the WDM; radio source 104 for generating high-frequency radio frequency signal; a signal driver 102 for generating high-speed data signal information-carrying; phase modulator 101 is realized by adjusting the bias voltage signal driver 102 carrying information generated by the high-speed data signal to the laser 100 the phase modulation of the optical signal produced; intensity modulator 103 using radio source 104 to output a high-frequency radio frequency signal, to the phase modulator 101 output modulation to the optical signal carrying information on the high-speed data signal to intensity modulation, the modulated to carry information after high-speed data signal which is output to the link module 11. Sending module 10 of each intensity modulator 103 output a modulated optical signal can be used as a light channel, carrying on the information needs to be transmitted. M is produced by the system the number of optical channels, M heating positive integer.

[10]

Link module 11 using WDM technology, the sending module 10 output signal M transmission through the optical fiber to a receiving module 12. Wherein the link module 11 comprises: multiplexer 110, optical fiber 111 reconciliation multiplexer 112. Multiplexer 110 using WDM technology, the intensity modulator 103 M one output of the multiplexed modulated optical signal in one optical link; connecting the multiplexer 110 reconciliation multiplexer 112 of the optical fiber 111 is used for transmitting the signal M for multiplexing; demultiplexer 112 the received optical signal is then demultiplexed to obtain independent M the optical signal, is output to the receiving module 12.

[11]

Receiving module 12 M independent of the received optical signal for filtering and demodulation, to obtain the high-speed data signal carrying information. Wherein receiving module 12 includes M of the plurality of processing elements, each processing unit comprises a series connection of the optical band-pass filter 120, the photoelectric detector 121 and demodulator 122. The optical band-pass filter 120 is used for removing the light it receives to the noise in the signal and interference; photoelectric detector 121 for optical band-pass filter 120 in the optical signal output by the demodulation to obtain the electrical signal; a demodulator 122 is used for the photoelectric detector 121 demodulates the electric signal output to the high-speed data signal carrying information.

[12]

The above-mentioned existing WDM-ROF of the WDM system can initially ROF transmission, however, have not been realized in a millimeter-wave radio transmission; the system is capable of realizing multi-wavelength-multi-channel transmission, the capacity of the signal channel is improved, but the provision of the light source of the optical signal is independent of the semiconductor laser, the price is expensive, increasing the cost of the system; in the high-speed data signal information-carrying modulation is carried out, the use of an expensive price M source of high frequency, to further increase the cost of the system; the existing WDM-ROF limited to the quantity of the light sources provided by the system, is limited to a large extent on the increase of the channel capacity.

[13]

Content of the invention

[14]

In view of this, the purpose of this invention is to provide a millimeter wave super-continuous spectrum-based WDM-ROF system, the system can reduce the system cost, to increase channel capacity, realize and utilize the millimeter-wave transmission information.

[15]

Another purpose of this invention is to provide a millimeter wave super-continuous spectrum-based WDM-ROF method, the method can reduce the cost, improve the channel capacity, realize and utilize the millimeter-wave transmission information.

[16]

In order to achieve the above-mentioned purpose, the technical scheme of the present invention in particular is realized like this:

[17]

A millimeter wave super-continuous spectrum-based wavelength division multiplexing-optical wireless composite WDM-ROF system, the system comprising: transmission device, link device and a receiving device;

[18]

The sending device comprises a light source module and N modulation module; said light source module using ultra-continuous spectrum light signal generating 2N-way independent optical signal, output N-way independent optical signal to the link apparatus, output N-way independent optical signal to the modulation module N; N the modulation module to modulate the optical signal path independent, output the modulated N path optical signal to the link apparatus; said 2N-way independent optical signal is the central wavelength is different and non-aliasing optical signal; said modulated N the Serial number of the optical signal the path 2i-1; said light source module of the device output to the link N path optical signal is not modulated, its Serial number as the 2i; the section 2i way the frequency of the optical signals with the subsection 2i-1 path difference of the frequency of the optical signals transmitted to the receiving device to carry information of the frequency of the millimeter wave radio frequency signal; N is bigger than or equal to 1 the positive integer; i is bigger than or equal to 1 and less than or equal to the integer of N;

[19]

The link device utilizes WDM N path of the modulated light signal and an unmodulated N path optical signal output to the receiving device;

[20]

N the receiving apparatus includes a processing unit, the processing unit N each processing element of the article received 2i-1 path optical signal and 2i path optical signal for processing, to obtain one millimeter wave radio frequency signal carrying information, transmitting the information carrying millimeter wave radio frequency signal.

[21]

In the above-mentioned device, the light source module comprises:

[22]

Laser, to connect through the optic fiber grating array, the generated pulse light coupled to the optical fiber;

[23]

Optical fiber, the pulse light into super-continuous spectrum light signal, output super-continuous spectrum light signal to the grating array;

[24]

Grating array, containing 2N a of the grating are connected in series, each of the grating to reflect the same as with the center wavelength of the optical signal, the stated 2N connected in series with respective grating of the received ultra-continuous spectrum light signal into 2N plurality of optical signals of different center wavelengths, and will contain 2N a path of the center wavelength of the optical signal which is output to the de-multiplexing device; section 2i with a center wavelength of the grating section 2i-1 of a difference of the center wavelength of the grating for the receiving device to carry information transmitted by the wavelength of the millimeter wave radio frequency signal;

[25]

Demultiplexer, containing received 2N a path of the center wavelength of the optical signal are divided, obtain 2N-way independent optical signal, for output Serial number 2i-1 N-way independent of the optical signal to the modulation module N, the output Serial number 2i N-way independent of the optical signal to the link apparatus.

[26]

In the above-mentioned device, the modulation module N each of the modulation module comprises: signal driver and the signal modulator;

[27]

The signal driver containing information for generating the high-speed data stream signal, output of the high-speed data stream containing information signal to the signal modulator;

[28]

The signal modulator receives the light source module output section 2i-1 path optical signal, the signal the high-speed data stream containing information of the signal modulation to the subsection 2i-1 path optical signal, outputs the modulated N-way independent optical signal to the link apparatus.

[29]

In the above-mentioned device, the link device comprises:

[30]

The multiplexer, the use of the modulated WDM N the optical signal path independent of and non-modulated way independent N multiplexing optical signals on one optical link;

[31]

Optical fiber, is connected with the multiplexer and the multiplexer, used for transmitting the optical signals on an optical link;

[32]

Demultiplexer, using WDM demultiplexing of the received optical signal to obtain the modulated N path optical signal and an unmodulated N path optical signal, output 2N-way independent optical signal to a receiving device.

[33]

In the above-mentioned device, the processing unit includes: 2 optical band-pass filter, a coupler, a photoelectric detector, a band-pass filter and an antenna;

[34]

Said 2 in optical band-pass filter of any optical band-pass filter is connected to one end of the link assembly, the other end is connected with one end of the coupler, for a received optical signal is band-pass filter, the output filter after the optical signal to the coupler; said 2 of optical band-pass filter in a receiving section 2i path optical signal, another receiving section 2i-1 path optical signal;

[35]

The other end of the coupler is connected with the one end of of the photoelectric detector, utilizes an optical heterodyne the received section 2i and-way light signal 2i-1 path optical signals are combined into a single light signal, output of the path of the combined optical signal to the photoelectric detector;

[36]

The photoelectric detector is connected with said another end of one end of the band-pass filter, is used for the path of the optical signal after the merger of the MOD, comprising direct current signal obtained, baseband signal and millimeter wave radio frequency signal carrying information of the electrical signal, the band-pass filter to output an electric signal;

[37]

The other end of the band-pass filter is connected with the antenna, the received electrical signal used for the band-pass filter, removes the DC signal and a baseband signal, output the information carrying millimeter wave radio frequency signal to said antenna;

[38]

The antenna is used for transmitting millimeter wave radio frequency signal carrying information.

[39]

A millimeter wave super-continuous spectrum-based wavelength division multiplexing-optical wireless composite WDM-ROF method, the method comprises:

[40]

A, using ultra-continuous spectrum light signal generating 2N-way independent optical signal, the optical signal of path independent N the modulation, to obtain the modulated N path optical signal and an unmodulated N path optical signal; said 2N-way independent optical signal is the central wavelength is different and non-aliasing optical signal; said modulated N the Serial number of the optical signal the path 2i-1; N the unmodulated of the Serial number of the optical signal the path 2i; section 2i way the frequency of the optical signals with the subsection 2i-1 path difference of the frequency of the optical signals to carry information for transmission of the frequency of the millimeter wave radio frequency signal; N is bigger than or equal to 1 the positive integer; i is bigger than or equal to 1 and less than or equal to the integer of N;

[41]

B, using wavelength division multiplexing WDM and optical fiber transmission path independent N of modulated and non-modulated optical signal of the optical signal path independent N;

[42]

C, the received 2N section in the optical path independent of the 2i and-way light signal 2i-1 path optical signal for processing, access road N millimeter wave radio frequency signal carrying information and transmitting.

[43]

In the above-mentioned method, steps A the use of super-continuous spectrum light signal generating 2N-way independent optical signal includes:

[44]

A1, the pulse optical signal is coupled into the non-linear optical fiber to produce super-continuous spectrum light signal;

[45]

A2, the super-continuous spectrum light signal containing comb wave obtained 2N a path of the center wavelength of the optical signal;

[46]

A3, containing 2N a path of the center wavelength of the optical signal by dividing 2N-way independent optical signal.

[47]

In the above-mentioned method, the steps of the received C 2N section in the optical path independent of the 2i and-way light signal 2i-1 path optical signal processing method comprising:

[48]

C1, the received 2N optical path independent of the band-pass filter;

[49]

C2, utilizes an optical heterodyne the filtered section 2i and-way light signal 2i-1 path optical signals are combined into a single light signal, the optical signal after the merger of the expression for E (t) = A (t) exp (i2 π f2i-1 t) +exp (i2 π f2i t), wherein A (t) baseband information-carrying signal is, f2i in section 2i way the frequency of the optical signals, f2i-1 in subsection 2i-1 way the frequency of the optical signals;

[50]

C3, according to the steps C2 to the expression of the path of the optical signal after the merger of the modular, comprising a direct current signal obtained, baseband signals and the radio-frequency signal the path of the electrical signal;

[51]

C4, the step C3 states a group electric signal of the band-pass filter, to remove the electrical signal comprises a direct current signal and a baseband signal, transmission of millimeter wave radio frequency signal carrying information.

[52]

By the above-mentioned technical scheme, the invention provides a millimeter wave super-continuous spectrum-based system and method for WDM-ROF, sending device comprises a light source module using ultra-continuous spectrum light signal generating 2N-way independent optical signal, omitting the existing WDM-ROF M in the system as an independent light source of the laser, the structure of the system is simplified, the cost is reduced; sending apparatus includes of the module only modulation N 2N in the optical signal path independent N paths for modulation, to N M/2, the omitted in the system of the existing WDM-ROF M/2 signal driver 102, the phase modulator 101 and intensity modulator 103, the prior and omit WDM-ROF M in the system of a source of high frequency, the structure of the further simplifies the system, reducing the cost of the system. The receiving device in the system of the received 2N-way independent optical signal modulated in a way independent N and non-modulated optical signal of the optical signal path independent N for processing, obtained millimeter wave radio frequency signal carrying information, does not need to be in order to realize millimeter-wave wireless transmission and adopts a high-frequency optical modulator and a high-frequency optical detector, to use lower cost to realize the millimeter-wave wireless transmission.

[53]

Description of drawings

[54]

Figure 1 is a structure diagram of the existing WDM-ROF system.

[55]

Figure 2 is a structure diagram of the invention is based on the super-continuous spectrum of millimetric wave WDM-ROF system.

[56]

Figure 3 is a structure diagram of the system of the present invention grating array.

[57]

Figure 4 is flow chart of this invention is based on the super-continuous spectrum of millimetric wave WDM-ROF method.

[58]

Mode of execution

[59]

In order to make the the purpose of this invention, the technical scheme, and advantages of the more clearly understood, the following embodiment and with reference to the attached diagram, further details of the present invention.

[60]

The invention provides a millimeter wave super-continuous spectrum-based system and method for WDM-ROF, the system sending device comprises a light source module using ultra-continuous spectrum light signal generating 2N-way independent optical signal, the modulation module, only N 2N-way independent of the optical signal modulation paths for N; receiving device received 2N-way independent optical signal modulated in a way independent N and non-modulated optical signal of the optical signal path independent N for processing, obtained millimeter wave radio frequency signal carrying information, the millimeter-wave wireless transmission.

[61]

Figure 2 is a structure diagram of the invention is based on the super-continuous spectrum of millimetric wave WDM-ROF system; Figure 3 is a structure diagram of the system of the present invention grating array. Now combining Figure 2 and Figure 3, to the invention is based on the super-continuous spectrum of millimetric wave WDM-ROF a description of the structure of the system, as follows:

[62]

In order to clear, the invention is based on the millimeter wave super-continuous spectrum defined WDM-ROF system, of the present invention system can produce WDM-ROF 2N-way independent optical signal, wherein N path modulated optical signal carrying the information, can be used as the system is used for transmission channels of information, the range of values of the N is greater than or equal to 1 the positive integer; the invention Figure 3 is shown to having a grating array of 10 channels based on super-continuous spectrum of millimeter wave WDM-ROF design of the system, is used for the super-continuous spectrum of an optical signal divided into 20 optical signals of different center wavelength, the grating array may be based on the specific structure of the embodiments of the present invention needs to produce the number of the design of the channel.

[63]

The invention is based on the super-continuous spectrum of millimetric wave WDM-ROF system includes: transmission device 20, link device 21 and receiving device 22. Wherein transmission device 20 includes a light source module (Figure 2 not shown) and N modulation module (Figure 2 is not shown); the receiving device includes a N processing unit (Figure 2 not shown).

[64]

Transmitting device 20 using ultra-light source module in the continuous spectrum light signal generating 2N-way independent optical signal, output N-way independent optical signal to the link apparatus 21, output to the optical signal path independent N N modulation module. Transmitting device 20 of module to the modulation in the optical signal path independent N for modulation, output the modulated N path optical signal to the link apparatus 21.

[65]

2N-way independent optical signal is different center wavelengths of the light signal and not overlapping; the modulated N the Serial number of the optical signal the path 2i-1; light source module is output to the link device is not-way light signal N modulated optical signal, the Serial number as the 2i. 2N in the optical path independent of the, section 2i way the frequency of the optical signals f2i and 2i-1 way the frequency of the optical signals f2i-1 for the receiving device for the difference of the millimeter wave radio frequency signal carrying information of the frequency fc. N is bigger than or equal to 1 the positive integer; i is bigger than or equal to 1 and less than or equal to the integer of N.

[66]

Link device 21 the use of WDM N the modulated and non-modulated way light signal N path of the optical signal output to a receiving device 22.

[67]

Receiving device 22 of each processing unit in the received section 2i-1 path optical signal and 2i path optical signal for processing, to obtain one millimeter wave radio frequency signal carrying information, transmitting the information carrying millimeter wave radio frequency signal.

[68]

Wherein the light source module comprises a laser 200, grating array 201, demultiplexer 202 and the optical fiber (fig. 2 not shown in); N each of the plurality of modulation module in a modulation module comprises a signal driver 203 and the signal modulator 204.

[69]

Laser 200 to connect through the optic fiber grating array 201, laser 200 will produce pulsed light coupled to the optical fiber, in order to make the optical fiber to produce the super-continuous spectrum light signal which is output to the grating array 201. According to the light pulse propagation in the optical fiber of the numerical analysis of the non-linear maximal equation can be obtained: by controlling the size of the incoming optical power of the optical fiber and can control the parameters of the optical fiber output of the spectral width of the continuous spectrum light signal. According to the above-mentioned content, in order to produce the spectrum wide and flat ultra-continuous spectrum light signal, the system of the present invention adopts the pulse laser and having a high non-linear photonic crystal fiber (PCF); wherein the pulse frequency of the pulse laser 10GHz the above; the photonic crystal fiber to use its non-linear, the pulse light is converted into super-continuous spectrum light signal.

[70]

Grating array 201 includes 2N a of the grating are connected in series, each grating reflection and the center of the optical signal of the same wavelength, instead of filtering optical signals with different center wavelengths; 2N connected in series with respective grating of the received ultra-continuous spectrum light signal into 2N plurality of optical signals of different center wavelengths, and will contain 2N a path of the center wavelength of the optical signal which is output to the demultiplexer 202. Grating array 201 structure as shown in Figure 3. Input to the grating array 201 of the optical signal is super-continuous spectrum, can be obtained also from the input end by 2N of the grating reflection divided by the two 2N plurality of optical signals of different center wavelengths, the stated 2N plurality of optical signals of different center wavelengths of the aliasing together to form a single light signal. 2N connected in series in the grating a, section 2i with a center wavelength of the grating section 2i-1 of a difference of the center wavelength of the grating for the system to carry information of the center wavelength of a millimeter wave radio frequency signal.

[71]

Demultiplexer 202 containing received 2N a path of the center wavelength of the optical signal are divided, obtain 2N independent optical signal, for output Serial number 2i-1 N-way independent of the optical signal to the modulation module, the output Serial number 2i N-way independent of the optical signal to the link apparatus 21. Demultiplexer 202 can adopt the existing waveguide array grating (AWG), this simple-to-de-multiplexer 202 containing 2N a path of the center wavelength of the optical signal is divided to obtain 2N a description of the optical signal path independent: demultiplexer 202 can be made of 1 * 32 of the waveguide array grating (AWG), wherein the input end 1 a, the output end is 32 a, is here of only 20 output; AWG includes an input waveguide, two plane coupling waveguide, array waveguide and the output waveguide; when the containing 20 the center wavelength of the optical signal entering the input waveguide, the street light signal through the input waveguide into the 1st plane coupling waveguide, the path of the optical signal 20 with different center wavelengths of the optical signal in a 1st plane coupling waveguide in the array waveguide is coupled into the diffraction and; because the array waveguide is incremented sequentially by many length of the waveguide paths, the optical signal diffracted by the array waveguide in the waveguide path after the different phase delay, array waveguide output of the 2nd plane the coupling waveguide in the optical signal in a coherent superposition of the different center wavelength 20-way independent optical signal. The stated 2N-way independent optical signal and for different center wavelengths of the light signal without aliasing.

[72]

Signal driver modulation module 203 containing information for generating the high-speed data stream signal, output of the high-speed data stream containing information signal to the signal modulator 204. Each high-speed data stream signal are 2.5Gbit/s baseband signal. A signal driver 203 to the specific structure of the content of the prior art, in this do not repeat.

[73]

Modulation module signal modulator 204 receiving light source module output section 2i-1 path optical signal, the signal the high-speed data stream containing information of the signal modulation to the subsection 2i-1 path optical signal, outputs the modulated N-way independent optical signal to the link apparatus 21. Signal modulator 204 can adopt the intensity modulation, phase modulation or frequency modulation of the high-speed data stream containing information of the signal modulation to the subsection 2i-1 path optical signal, the specific method for modulation of the content of the prior art. Prior SUMMARY statement signal modulator 204 method for modulation of the signal, in particular to: signal modulator 204 from the input port receiving section 2i-1-way light signal of the modulator is divided into two beams in the respectively two waveguide arms to spread the, using electro-optical effect and high-speed data stream signal change of the information contained in the two modulator inner wave guide arm of modulating voltage in order to change the refractive index of the waveguide, two waveguide arms so as to change the output of the phase difference between the two beams of light; wherein when the high-speed data stream signal contains the information of the 1 time, the two waveguide arms of the modulating voltage output of the phase difference of the two light beams is an integer multiple of 2 π, two beams of light strong [...] , the output and strengthen 2i-1 path optical signal; when the high-speed data stream signal contains the information of the 0 time, the two waveguide arms of the modulating voltage output of the phase difference of the two light beams is an integer multiple of π, coherent disappears two beams of light, there is no optical signal output. Signal modulator 204 can adopt the existing maze modulator, the structure of the content of the prior art, in this do not repeat.

[74]

Link device 21 comprises a multiplexer 210, optical fiber 211 reconciliation multiplexer 212. Wherein one end of the optical fiber is connected with the multiplexer 210, the other end is connected with a demultiplexer 212.

[75]

Multiplexer 210 by the modulated WDM N-way independent of and non-modulated optical signal of N-way independent of the multiplexing of the optical signals on one optical link, through the optical fiber 211 is transmitted to a demultiplexer 212. Demultiplexer 212 using WDM demultiplexing of the received optical signal to obtain the modulated N-way independent of and non-modulated optical signal of the optical signal path independent N, and output to a receiving device 22. Multiplexer 210 reconciliation multiplexer 212 can adopt the existing waveguide array grating, in this no longer to repeat its structure.

[76]

Receiving device 22 a included in the processing unit N each processing unit comprises: 2 optical band-pass filter 220, a coupler 221, a photoelectric detector 222, a band-pass filter 223, and an antenna 224.

[77]

2 optical band-pass filter 220 in each optical band-pass filter 220 is connected with one end of the link assembly 21 in the demultiplexer 212, the other end is connected with the coupler 221 one end of the, used for a received optical signal is band-pass filtered, removal of the received optical signal independent of the noise and interference, the output filter after the optical signal to coupler 221. 2 optical band-pass filter 220 receives one of 2i-way independent optical signal, the other receiving section 2i-1-way independent optical signal.

[78]

Coupler 221 is connected with one end of the other photoelectric detector 222 one end of, the received by optical heterodyne the post-filter section 2i-way independent optical signal and the filtered section 2i-1-way independent optical signal are combined into a single light signal, the path of the combined output of the light signal to photo-detector 222. If coupler 221 receives the two light signals are respectively section 2i-way independent optical signal and 2i-1-way independent optical signal, by coupler 221 output of the path of the optical signal after the merger of the expression is:

[79]

E (t) = A (t) exp (i2 π f2i-1 t) +exp (i2 π f2i t)

[80]

Wherein A (t) is the baseband signal carrying information, f2i in section 2i way the frequency of the optical signals, f2i-1 in subsection 2i-1 way the frequency of the optical signals.

[81]

Photoelectric detector 222 is connected with the other end of the band-pass filter 223 one end of, the combined optical signal used for the modular, comprising direct current signal obtained, baseband signal and millimeter wave radio frequency signal carrying information of the electrical signal, and output the electric signal to a band-pass filter 223. If a certain a photoelectric detector 222 receives the optical signal after the merger of the expression is:

[82]

E (t) = A (t) exp (i2 π f2i-1 t) +exp (i2 π f2i t)

[83]

Wherein A (t) is the baseband signal carrying information; the photoelectric detector 222 after the merger of the MOD the optical signal of the path of the electrical signal obtained is expressed as:

[84]

I (t) =μ|A (t) exp (i2 π f2i-1 t) +exp (i2 π f2i t) |2

[85]

= μ (1 +A2 (t) +A (t) exp (i2 π fc t) +A (t) exp (-i2 π fc t))

[86]

= μ (1 +A2 (t) + 2A (t) cos (2 π fc t))

[87]

fc = f2i-f2i-1

[88]

Wherein μ is a conversion coefficient; fc to receiving device 22 carrying information of the frequency of the millimeter wave radio frequency signal. The expression can be obtained in accordance with the electrical signal, the photoelectric detector 222 output electrical signal comprises a DC signal, baseband signal A2 (t) and radio frequency signal A (t) cos (2 π fc t). Photoelectric detector 222 to the specific structure of the content of the prior art, in this do not repeat.

[89]

Band-pass filter 223 is connected with one end of the other antenna 224, used for the received electrical signal to a band-pass filter, removes the DC signal and a baseband signal, output the information carrying millimeter wave radio frequency signal to the antenna 224, through the antenna 224 for wireless transmission. Preferably, in the system of the present invention each of the band-pass filter 223 with the emission of the center frequency of the millimeter wave radio frequency signal carrying information of the frequency fc the same.

[90]

Figure 4 is flow chart of this invention is based on the super-continuous spectrum of millimetric wave WDM-ROF method. Now with Figure 4, the present invention is based on the super-continuous spectrum of millimetric wave WDM-ROF method to note, as follows:

[91]

Step 401: using ultra-continuous spectrum light signal generating 2N-way independent optical signal, the optical signal of path independent N the modulation, to obtain the modulated N path optical signal and an unmodulated N path optical signal; said 2N-way independent optical signal is the central wavelength is different and non-aliasing optical signal;

[92]

The modulated N the Serial number of the optical signal the path 2i-1; an unmodulated N-way light signal for the Serial numbers of the 2i; section 2i way the frequency of the optical signals with the subsection 2i-1 path difference of the frequency of the optical signals to carry information for transmission of the frequency of the millimeter wave radio frequency signal.

[93]

N is bigger than or equal to 1 the positive integer; i is bigger than or equal to 1 and less than or equal to the integer of N.

[94]

In this step, using ultra-continuous spectrum light signal generating 2N optical signal path independent of the method comprises:

[95]

Step 4011, pulsed light signal to be coupled into the non-linear optical fiber to produce super-continuous spectrum light signal;

[96]

Step 4012, the super-continuous spectrum light signal containing comb wave obtained 2N a path of the center wavelength of the optical signal;

[97]

Step 4013, containing 2N a path of the center wavelength of the optical signal by dividing 2N-way independent optical signal.

[98]

In step 4013 in, can be used by the demultiplexer of the existing 2N of different center wavelength optical signal aliasing a segmentation of the path of the optical signal, to obtain 2N paths of different independent of the center wavelength of the optical signal.

[99]

N path independent of the method for modulating optical signals in order to utilize the signal modulation containing the information of the high-speed data stream signal modulates the Serial number as the 2i-1 N-way independent of in the optical signal, the modulation method for the content of that of the prior art, in that only a simple explanation:

[100]

Step 4014, containing N information of the generated high-speed data stream signal;

[101]

Step 4015, the received section 2i-1-way independent optical signals are respectively the modulator is divided into two beams in the two waveguide arms of propagation;

[102]

Step 4016, to utilize electro-optic effect and high-speed data stream signal change of the information contained in the two modulator inner wave guide arm of modulating voltage in order to change the refractive index of the waveguide, changing the two waveguide arms output of the phase difference between the light beams, after the output signal is modulated 2i-1-way independent optical signal.

[103]

Step 402: wavelength division multiplexing WDM and optical fiber transmission path independent N of modulated and non-modulated optical signal of the optical signal path independent N;

[104]

Using wavelength division multiplexing of the modulated optical signal path independent N and non-modulated N-way independent of the multiplexing of the optical signals on one optical link, for transmission through the optical fiber. Use of existing demultiplexing device or other device, through the optical fiber to the received optical signal has demultiplexed way independent N of modulated and non-modulated optical signal of the optical signal path independent N.

[105]

The 2N multiplexing way independent optical signals on one optical link method, and the light received by the optical link for signal demultiplexing 2N path independent of the method of the optical signal to the content of the prior art, in this do not repeat.

[106]

Step 403: received 2N section in the optical path independent of the 2i and-way light signal 2i-1 path optical signal for processing, obtained carry information N path and millimeter wave radio frequency signal;

[107]

In this step, the received 2N section in the optical path independent of the 2i and-way light signal 2i-1 path optical signal processing method comprising:

[108]

Step 4031, the received 2N optical path independent of the band-pass filter;

[109]

Step 4032, utilizes an optical heterodyne the filtered section 2i and-way light signal 2i-1 path optical signals are combined into a single light signal, the optical signal after the merger of the expression is:

[110]

E (t) = A (t) exp (i2 π f2i-1 t) +exp (i2 π f2i t)

[111]

Wherein A (t) is the baseband signal carrying information, f2i in section 2i way the frequency of the optical signals, f2i-1 in subsection 2i-1 way the frequency of the optical signals;

[112]

Step 4033, according to step 4032 to the expression of the path of the optical signal after the merger of the modular, comprising a direct current signal obtained, baseband signals and the radio-frequency signal the path of the electrical signal;

[113]

Step 4034, in step 4033 states a group electric signal of the band-pass filter, to remove the electrical signal comprises a direct current signal and a baseband signal, transmission of millimeter wave radio frequency signal carrying information.

[114]

In step 403 in, first of all the received 2N optical path independent of the band-pass filter, in order to eliminate in each optical signal mixed with noise and interference.

[115]

presently only in order to form the 10 channel, for example, to the invention is based on the super-continuous spectrum of millimetric wave WDM-ROF system to note, as follows:

[116]

N as in the embodiment 10, section 2i-1 path optical signal is modulated, section 2i path optical signal is not modulated.

[117]

As shown in Figure 3, a transmitting device 20 of the grating array 201 including 20 a grating, the center wavelength are 1545.0 nm and 1545.32 nm, 1546.0 nm and 1546.32 nm, 1547.0 nm and 1547.32 nm, 1548.0 nm and 1548.32 nm, 1549.0 nm and 1549.32 nm, 1551.0 nm and 1551.32 nm, 1552.0 nm and 1552.32 nm, 1553.0 nm and 1553.32 nm, 1554.0 nm and 1554.32 nm, 1555.0 nm and 1555.32 nm. Subsection 2i-1 a grating and the section 2i a center wavelength of the grating interval is 0.32 nm in other words 40GHz, this is also for the wireless transmission of millimeter wave radio frequency signal frequency.

[118]

Grating array 201 containing output in 20 a path of the center wavelength of the incident optical signal to a demultiplexer 202 of the 1 × 32 in the waveguide array grating (AWG), at this moment, the only 20 output end, of the output produced by 20-way independent optical signal, these independent optical signal can be used as independent light source. This 20 path independent of the size of the center wavelength of the light source in accordance with the ordering sequentially 1545.0 nm and 1545.32 nm, 1546.0 nm and 1546.32 nm, 1547.0 nm and 1547.32 nm, 1548.0 nm and 1548.32 nm, 1549.0 nm and 1549.32 nm, 1551.0 nm and 1551.32 nm, 1552.0 nm and 1552.32 nm, 1553.0 nm and 1553.32 nm, 1554.0 nm and 1554.32 nm, 1555.0 nm and 1555.32 nm.

[119]

The modulation module of the embodiment of the Serial number as the 2i-1 N the optical signal path independent of signal modulation, in particular signal modulation method and Figure 2 the same, in this do not repeat. The embodiment of the light source module for the unmodulated the Serial numbers of the 2i N-way independent of the optical signal is directly output to the link device 21 as a multiplexer in 211 of the 32 × 1 in the waveguide array grating, modulation module as the Serial number of the modulated 2i-1 N-way independent of the optical signal output device to the link 21 as the multiplexer 211 of the 32 × 1 in the waveguide array grating, 32 × 1 wavelength division multiplexing the waveguide grating array of the received 20 multiplexed way independent optical signals on one optical link, the optical fiber for transmission. Preferably, after the optical signal of wavelength division multiplexing in optical fiber for the transmission distance of 5 km.

[120]

The link device 21 as a demultiplexer 212 received the waveguide grating array of the optical signal is then demultiplexed, dividing the resulting 10 path independent information-carrying optical signal and the 10 way not with information of the independent optical signal.

[121]

At the receiving device 22 in, N in a processing unit in the processing unit and coupler 221 utilizes an optical heterodyne the article after filtering 2i-1 path optical signal and the filtered section 2i path optical signals are combined into a single light signal, the path of the combined output of the light signal to photo-detector 222 MOD in operation, containing a DC signal obtained, baseband signal and information-carrying signal of the radio frequency signal. Receiving device 22 using the central frequency is 40GHz, bandwidth of 5GHz the band-pass filter 223 to the electrical signal to a band-pass filter, for filtering out the direct current signal and a baseband signal, obtained millimeter wave radio frequency signal carrying information, its specific process and Figure 2 the same, in this do not repeat. Receiving device 22 will carry the information of the millimeter-wave radio-frequency signal through the antenna 224 for wireless transmission.

[122]

The invention of the above-mentioned embodiment, the sending device comprises a light source module using ultra-continuous spectrum light signal generating 2N-way independent optical signal, omitting the existing WDM-ROF M in the system as an independent light source of the laser, the structure of the system is simplified, the cost is reduced; sending apparatus includes of the module only modulation N 2N in the optical signal path independent N paths for modulation, to N M/2, the omitted in the system of the existing WDM-ROF M/2 signal driver 102, the phase modulator 101 and intensity modulator 103, the prior and omit WDM-ROF M in the system of a source of high frequency, the structure of the further simplifies the system, reducing the cost of the system. The receiving device in the system of the received 2N-way independent optical signal modulated in a way independent N and non-modulated optical signal of the optical signal path independent N for processing, obtained millimeter wave radio frequency signal carrying information, does not need to be in order to realize millimeter-wave wireless transmission and adopts a high-frequency optical modulator and a high-frequency optical detector, to use lower cost to realize the millimeter-wave wireless transmission.

[123]

For this invention the stated above the better practical example , is not used to limit the invention, where in the present invention within the spirit and principle of the, any modification of the, equivalent replacement, improved, and the like, shall be included in this invention within the scope of protection.



[1]

The invention provides millimeter wave WDM-ROF (Wavelength Division Multiplexing-Radio Over Fiber) system and method based on a supercontinuum. A light source module contained in a transmitting device in the system generates 2N paths of independent optical signals by utilizing a supercontinuum optical signal, and N modulating modules only modulate N paths in the 2N paths of independent optical signals; a link device is used for transmitting N paths of independent modulated optical signals and N paths of independent unmodulated optical signals by utilizing WDM through an optical link; and a receiving device is used for processing the N paths of independent modulated optical signals and the N paths of independent unmodulated optical signals in 2N paths of independent received optical signals to obtain a millimeter wave radio-frequency signal carrying information so that millimeter wave wireless transmission is realized. By adopting the method and the system, the cost can be lowered, the channel capacity is improved and information is transmitted by utilizing a millimeter wave.



1. A millimeter wave super-continuous spectrum-based wavelength division multiplexing-optical wireless composite WDM-ROF system, characterized in that the system includes: transmission device, link device and a receiving device;

The sending device comprises a light source module and N modulation module; said light source module using ultra-continuous spectrum light signal generating 2N-way independent optical signal, output N-way independent optical signal to the link apparatus, output N-way independent optical signal to the modulation module N; N the modulation module to modulate the optical signal path independent, output the modulated N path optical signal to the link apparatus; said 2N-way independent optical signal is the central wavelength is different and non-aliasing optical signal; said modulated N the Serial number of the optical signal the path 2i-1; said light source module of the device output to the link N path optical signal is not modulated, its Serial number as the 2i; the section 2i way the frequency of the optical signals with the subsection 2i-1 path difference of the frequency of the optical signals transmitted to the receiving device to carry information of the frequency of the millimeter wave radio frequency signal; N is bigger than or equal to 1 the positive integer; i is bigger than or equal to 1 and less than or equal to the integer of N;

The link device utilizes WDM N path of the modulated light signal and an unmodulated N path optical signal output to the receiving device;

N the receiving apparatus includes a processing unit, the processing unit N each processing element of the article received 2i-1 path optical signal and 2i path optical signal for processing, to obtain one millimeter wave radio frequency signal carrying information, transmitting the information carrying millimeter wave radio frequency signal.

2. Device according to Claim 1, characterized in that the light source module comprises:

Laser, to connect through the optic fiber grating array, the generated pulse light coupled to the optical fiber;

Optical fiber, the pulse light into super-continuous spectrum light signal, output super-continuous spectrum light signal to the grating array;

Grating array, containing 2N a of the grating are connected in series, each of the grating to reflect the same as with the center wavelength of the optical signal, the stated 2N connected in series with respective grating of the received ultra-continuous spectrum light signal into 2N plurality of optical signals of different center wavelengths, and will contain 2N a path of the center wavelength of the optical signal which is output to the de-multiplexing device; section 2i with a center wavelength of the grating section 2i-1 of a difference of the center wavelength of the grating for the receiving device to carry information transmitted by the wavelength of the millimeter wave radio frequency signal;

Demultiplexer, containing received 2N a path of the center wavelength of the optical signal are divided, obtain 2N-way independent optical signal, for output Serial number 2i-1 N-way independent of the optical signal to the modulation module N, the output Serial number 2i N-way independent of the optical signal to the link apparatus.

3. System according to Claim 1, characterized in that the modulation module N each of the modulation module comprises: signal driver and the signal modulator;

The signal driver containing information for generating the high-speed data stream signal, output of the high-speed data stream containing information signal to the signal modulator;

The signal modulator receives the light source module output section 2i-1 path optical signal, the signal the high-speed data stream containing information of the signal modulation to the subsection 2i-1 path optical signal, outputs the modulated N-way independent optical signal to the link apparatus.

4. System according to Claim 1, characterized in that the link device comprises:

The multiplexer, the use of the modulated WDM N the optical signal path independent of and non-modulated way independent N multiplexing optical signals on one optical link;

Optical fiber, is connected with the multiplexer and the multiplexer, used for transmitting the optical signals on an optical link;

Demultiplexer, using WDM demultiplexing of the received optical signal to obtain the modulated N path optical signal and an unmodulated N path optical signal, output 2N-way independent optical signal to a receiving device.

5. System according to Claim 1, characterized in that said processing unit comprises: 2 optical band-pass filter, a coupler, a photoelectric detector, a band-pass filter and an antenna;

Said 2 in optical band-pass filter of any optical band-pass filter is connected to one end of the link assembly, the other end is connected with one end of the coupler, for a received optical signal is band-pass filter, the output filter after the optical signal to the coupler; said 2 of optical band-pass filter in a receiving section 2i path optical signal, another receiving section 2i-1 path optical signal;

The other end of the coupler is connected with the one end of of the photoelectric detector, utilizes an optical heterodyne the received section 2i and-way light signal 2i-1 path optical signals are combined into a single light signal, output of the path of the combined optical signal to the photoelectric detector;

The photoelectric detector is connected with said another end of one end of the band-pass filter, is used for the path of the optical signal after the merger of the MOD, comprising direct current signal obtained, baseband signal and millimeter wave radio frequency signal carrying information of the electrical signal, the band-pass filter to output an electric signal;

The other end of the band-pass filter is connected with the antenna, the received electrical signal used for the band-pass filter, removes the DC signal and a baseband signal, output the information carrying millimeter wave radio frequency signal to said antenna;

The antenna is used for transmitting millimeter wave radio frequency signal carrying information.

6. A millimeter wave super-continuous spectrum-based wavelength division multiplexing-optical wireless composite WDM-ROF method, characterized in that the method comprises:

A, using ultra-continuous spectrum light signal generating 2N-way independent optical signal, the optical signal of path independent N the modulation, to obtain the modulated N path optical signal and an unmodulated N path optical signal; said 2N-way independent optical signal is the central wavelength is different and non-aliasing optical signal; said modulated N the Serial number of the optical signal the path 2i-1; N the unmodulated of the Serial number of the optical signal the path 2i; section 2i way the frequency of the optical signals with the subsection 2i-1 path difference of the frequency of the optical signals to carry information for transmission of the frequency of the millimeter wave radio frequency signal; N is bigger than or equal to 1 the positive integer; i is bigger than or equal to 1 and less than or equal to the integer of N;

B, using wavelength division multiplexing WDM and optical fiber transmission path independent N of modulated and non-modulated optical signal of the optical signal path independent N;

C, the received 2N section in the optical path independent of the 2i and-way light signal 2i-1 path optical signal for processing, access road N millimeter wave radio frequency signal carrying information and transmitting.

7. Method according to Claim 6, characterized in that steps the A using ultra-continuous spectrum light signal generating 2N-way independent optical signal includes:

A1, the pulse optical signal is coupled into the non-linear optical fiber to produce super-continuous spectrum light signal;

A2, the super-continuous spectrum light signal containing comb wave obtained 2N a path of the center wavelength of the optical signal;

A3, containing 2N a path of the center wavelength of the optical signal by dividing 2N-way independent optical signal.

8. Method according to Claim 1, characterized in that step of the received C 2N section in the optical path independent of the 2i and-way light signal 2i-1 path optical signal processing method comprising:

C1, the received 2N optical path independent of the band-pass filter;

C2, utilizes an optical heterodyne the filtered section 2i and-way light signal 2i-1 path optical signals are combined into a single light signal, the optical signal after the merger of the expression for E (t) = A (t) exp (i2 π f2i-1 t) +exp (i2 π f2i t), wherein A (t) baseband information-carrying signal is, f2i in section 2i way the frequency of the optical signals, f2i-1 in subsection 2i-1 way the frequency of the optical signals;

C3, according to the steps C2 to the expression of the path of the optical signal after the merger of the modular, comprising a direct current signal obtained, baseband signals and the radio-frequency signal the path of the electrical signal;

C4, the step C3 states a group electric signal of the band-pass filter, to remove the electrical signal comprises a direct current signal and a baseband signal, transmission of millimeter wave radio frequency signal carrying information.