WO2023273797A1

WO2023273797A1 - Optical millimeter wave receiving end and transmitting end, system, demodulation method, and modulation method

Info

Publication number: WO2023273797A1
Application number: PCT/CN2022/096987
Authority: WO
Inventors: 范忱
Original assignee: 中兴通讯股份有限公司
Priority date: 2021-06-30
Filing date: 2022-06-02
Publication date: 2023-01-05
Also published as: CN115549791A

Abstract

Embodiments of the present application relate to the technical field of optical communications, and in particular, to an optical millimeter wave receiving end and transmitting end, a system, a demodulation method, and a modulation method. The optical millimeter wave receiving end comprises: a first coupler used for dividing a received optical signal into a first optical signal, a second optical signal, and a third optical signal; and a demodulation module used for dividing the third optical signal into a fourth optical signal and a fifth optical signal after rotating the polarization state of local oscillator light in the third optical signal, and acquiring a first radio-frequency signal, a second radio-frequency signal, a third radio-frequency signal, and a fourth radio-frequency signal by respectively filtering away a lower sideband of the first optical signal, an upper sideband of the second optical signal, a lower sideband of the fourth optical signal, and an upper sideband of the fifth optical signal.

Description

Optical carrier millimeter wave receiving end, transmitting end, system, demodulation method and modulation method

Cross References to Related Applications

This application is based on the Chinese patent application with the application number "202110735797.X" and the filing date is June 30, 2021, and claims the priority of the Chinese patent application. The entire content of the Chinese patent application is incorporated herein by reference. into this application.

technical field

The embodiments of the present application relate to the technical field of optical communication, and in particular to an optical-carrying millimeter wave receiving end, transmitting end, system, demodulation method, and modulation method.

Background technique

With the gradual popularization of the 5th Generation Mobile Communication Technology (5G for short) and the rapid development of various Internet services, 5G technology is gradually developing towards millimeter wave, and the light-borne millimeter wave wireless system, that is, coherent optical communication Technology attracts more and more research interest. In coherent optical communication technology, there are frequency deviation and phase noise caused by the phase and frequency inconsistency between local oscillator light and signal light. The random birefringence of optical fiber will cause two orthogonal transmissions. Mixing of polarization states, dispersion in optical fibers can lead to problems such as inter-symbol interference, these problems will cause poor quality of coherent optical communication systems, the industry generally uses digital signal processing methods to restore signals, or configures polarization controllers at the receiving end , Adding lasers to modify the coherent optical communication system.

However, the method of using digital signal processing modules to restore the signal requires the introduction of a large number of digital signal processing modules, and the method of configuring polarization controllers and adding lasers at the receiving end will also introduce a large number of redundant modules, which lead to optical load mm Wave wireless system is too complicated and the input cost is too high.

Contents of the invention

An embodiment of the present application provides an optical-carrying millimeter-wave receiving end, including: a first coupler, configured to divide the received optical signal into a first optical signal, a second optical signal, and a third optical signal; wherein , each optical signal includes local oscillator light and signal light, the signal light includes first polarized signal light and second polarized signal light, and the upper sideband of the first polarized signal light is modulated with the first radio frequency signal, so The lower sideband of the first polarized signal light is modulated with a second radio frequency signal, the upper sideband of the second polarized signal light is modulated with a third radio frequency signal, and the lower sideband of the second polarized signal light is modulated with a fourth radio frequency signal radio frequency signal, the polarization state of the first polarized signal light is orthogonal to the polarization state of the second polarized signal light, and the polarization state of the local oscillator light is the same as that of the first polarized signal light; demodulation A module, configured to rotate the polarization state of the local oscillator light in the third optical signal, divide the rotated third optical signal into a fourth optical signal and a fifth optical signal, and pass respectively filtering out the lower sideband of the first optical signal, the upper sideband of the second optical signal, the lower sideband of the fourth optical signal, and the upper sideband of the fifth optical signal to obtain the The first radio frequency signal, the second radio frequency signal, the third radio frequency signal and the fourth radio frequency signal; wherein, the polarization state of the rotated local oscillator light is the same as that of the second polarization signal The polarization state of the light is the same.

The embodiment of the application also provides an optical-carrying millimeter-wave transmitter, including: a laser, a third coupler, a modulator, a polarization controller, and a fourth coupler; the laser is connected to the third coupler, and the first The three couplers are connected to the modulator and the polarization controller, and both the modulator and the polarization controller are connected to the fourth coupler; the laser is used to emit laser light; the third coupler is used to The laser light emitted by the laser is divided into a first path of light for carrying modulation signals and a second path of light as local oscillator light; the modulator is used for modulating the first path of radio frequency signals to the first path of light The upper sideband of the first polarization state optical carrier of the first path of light is adjusted to the lower sideband of the first polarization state optical carrier of the first path of light to obtain the first polarization signal light carrying the modulated signal; and the second path of radio frequency signal The three radio frequency signals are adjusted to the upper sideband of the second polarization state optical carrier of the first optical path, and the fourth radio frequency signal is adjusted to the lower sideband of the second polarization state optical carrier of the first optical path to obtain the carried The second polarized signal light of the modulated signal; wherein, the polarization state of the first polarized signal light is orthogonal to the polarization state of the second polarized signal light; the polarization controller is used to change the polarization state of the local oscillator light modulated to be the same as the polarization state of the first polarized signal light; the fourth coupler is used to combine the first polarized signal light, the second polarized signal light and the local oscillator light , enter the optical fiber link for transmission.

An embodiment of the present application also provides an optical millimeter wave wireless system, including the above optical optical millimeter wave receiving end and optical optical millimeter wave transmitting end.

An embodiment of the present application also provides an optical-carrying millimeter-wave demodulation method, the method comprising: dividing the received optical signal into a first optical signal, a second optical signal, and a third optical signal; wherein, each One optical signal includes local oscillator light and signal light, the signal light includes first polarized signal light and second polarized signal light, the upper sideband of the first polarized signal light is modulated with the first radio frequency signal, and the first polarized signal light The lower sideband of a polarized signal light is modulated with a second radio frequency signal, the upper sideband of the second polarized signal light is modulated with a third radio frequency signal, and the lower sideband of the second polarized signal light is modulated with a fourth radio frequency signal , the polarization state of the first polarized signal light is orthogonal to the polarization state of the second polarized signal light, and the polarization state of the local oscillator light is the same as that of the first polarized signal light; The polarization state of the local oscillator light in the three optical signals is rotated, and the rotated third optical signal is divided into a fourth optical signal and a fifth optical signal; wherein, the rotated local oscillator light The polarization state of the second polarized signal light is the same as that of the second polarized signal light; the lower sideband of the first optical signal, the upper sideband of the second optical signal, and the lower edge of the fourth optical signal are respectively filtered out and the upper sideband of the fifth optical signal, and acquire the first radio frequency signal, the second radio frequency signal, the third radio frequency signal and the fourth radio frequency signal.

The embodiment of the present application also provides an optical-carrying millimeter-wave modulation method, the method comprising: dividing the laser light emitted by the laser into a first path of light for carrying modulation signals and a second path of light as local oscillator light; The first radio frequency signal is modulated to the upper sideband of the first polarization state optical carrier of the first light, and the second radio frequency signal is modulated to the lower sideband of the first polarization state optical carrier of the first light, Obtain the first polarized signal light carrying the modulation signal; modulate the third radio frequency signal to the upper sideband of the second polarization state optical carrier of the first light, and modulate the fourth radio frequency signal to the first radio frequency signal The lower sideband of the second polarization state optical carrier of the light is obtained to carry the second polarized signal light of the modulated signal; the polarization state of the local oscillator light is adjusted to be the same as the polarization state of the first polarized signal light; the After the first polarized signal light, the second polarized signal light and the local oscillator light are combined, they are input into an optical fiber link for transmission.

Description of drawings

FIG. 1 is a schematic structural diagram of an optical-carrying millimeter-wave receiving end according to an embodiment of the present application;

FIG. 2 is a second structural diagram of an optical-carrying millimeter-wave receiving end according to an embodiment of the present application;

FIG. 3 is a schematic structural diagram of an optical-carrying millimeter wave receiving end according to an embodiment of the present application;

Fig. 4 is a structural schematic diagram 4 of an optical-carrying millimeter-wave receiving end according to an embodiment of the present application;

FIG. 5 is a schematic structural diagram of an optical-carrying millimeter-wave transmitting end according to another embodiment of the present application;

FIG. 6 is a schematic structural diagram of an optical-carrying millimeter-wave wireless system according to another embodiment of the present application;

FIG. 7 is a flow chart of an optical millimeter wave demodulation method according to another embodiment of the present application;

Fig. 8 is provided according to another embodiment of the present application to filter out the lower sideband of the first optical signal, the upper sideband of the second optical signal, the lower sideband of the fourth optical signal and the upper edge of the fifth optical signal Band, the flow chart of obtaining the first radio frequency signal, the second radio frequency signal, the third radio frequency signal and the fourth radio frequency signal;

Fig. 9 is a flowchart of an optical-borne millimeter-wave modulation method according to another embodiment of the present application.

detailed description

The main purpose of the embodiment of the present application is to propose an optical millimeter wave receiving end, transmitting end, system, demodulation method and modulation method, which can effectively reduce the complexity of the optical millimeter wave wireless system, thereby reducing the system input costs.

In order to make the purpose, technical solutions and advantages of the embodiments of the present application clearer, the embodiments of the present application will be described in detail below with reference to the accompanying drawings. However, those of ordinary skill in the art can understand that in each embodiment of the application, many technical details are provided for readers to better understand the application. However, even without these technical details and various changes and modifications based on the following embodiments, the technical solutions claimed in this application can also be realized. The division of the following embodiments is for the convenience of description, and should not constitute any limitation to the specific implementation of the present application, and the various embodiments can be combined and referred to each other on the premise of no contradiction.

An embodiment of the present application relates to an optical-carrying millimeter-wave receiving end. The implementation details of the optical-carrying millimeter-wave receiving end of this embodiment are described in detail below, and the following content is only implementation details provided for easy understanding, and is not necessary for implementing this solution.

A schematic diagram of an optical-carrying millimeter-wave receiving end in this embodiment may be shown in FIG. 1 , including: a first coupler 11 and a demodulation module 12 , and the first coupler 11 is connected to the demodulation module 12 .

The first coupler 11 is used to divide the received optical signal into a first optical signal, a second optical signal and a third optical signal.

Specifically, each of the three optical signals of the first optical signal, the second optical signal, and the third optical signal includes local oscillator light and signal light, and the signal light includes the first polarized signal light and the second polarized signal light, the upper sideband of the first polarized signal light is modulated with the first radio frequency signal, the lower sideband of the first polarized signal light is modulated with the second radio frequency signal, and the upper sideband of the second polarized signal light is modulated with the second radio frequency signal Three radio frequency signals, the lower sideband of the second polarized signal light is modulated with a fourth radio frequency signal, the polarization state of the first polarized signal light is orthogonal to the polarization state of the second polarized signal light, and the polarization state of the local oscillator light is the same as that of the first polarized signal light The polarization states of the polarized signal lights are the same.

In a specific implementation, the transmitting end modulates four independent baseband signals into one optical signal, the first coupler 11 can receive the optical signal sent by the sending end in real time, and the first coupler 11 receives the optical signal sent by the sending end Finally, the received optical signal can be divided into the first optical signal, the second optical signal and the third optical signal, and the optical signal is split to facilitate subsequent demodulation.

In one example, the first coupler 11 divides the received optical signal into the first optical signal, the second optical signal and the third optical signal, which can multiplex the received optical signals and output the first The first optical signal, the second optical signal, and the third optical signal are the same as the optical signal received by the first coupler 11 .

The demodulation module 12 is used to rotate the polarization state of the local oscillator light in the third optical signal, divide the rotated third optical signal into a fourth optical signal and a fifth optical signal, and filter the Get the first radio frequency signal, the second radio frequency signal, The third radio frequency signal and the fourth radio frequency signal.

Specifically, the polarization state of the rotated local oscillator light is the same as that of the second polarized signal light.

In a specific implementation, after receiving the first signal light, the second signal light and the third signal light transmitted by the first coupler 11, the demodulation module 12 directly filters out the lower sideband of the first signal light and the upper sideband of the second signal light, after rotating the polarization state of the local oscillator light in the third signal light by 90°, the rotated third optical signal is divided into the fourth optical signal and the fifth optical signal signal, the polarization state of the local oscillator light rotated by 90° is the same as the polarization state of the second polarized signal light, and then filter the lower sideband of the fourth optical signal and the upper sideband of the fifth optical signal, according to the retained first The first radio frequency signal is obtained from the upper sideband of the signal light, the second radio frequency signal is obtained from the lower sideband of the second signal light, the third radio frequency signal is obtained from the upper sideband of the fourth optical signal, and the fifth radio frequency The lower sideband of the signal acquires the fourth radio frequency signal. The embodiments of the present application do not need to use any digital signal processing module, and only use existing hardware to realize the separation of four signals, which effectively reduces the complexity and cost of the optical millimeter wave wireless system.

In this embodiment, compared with the technical solution of using digital signal processing method to restore the signal, or configuring a polarization controller at the receiving end and adding a laser to modify the coherent optical communication system, the embodiment of the present application, in The receiving end does not need to use any digital signal processing module, nor does it need to configure a polarization controller or add a laser at the receiving end. Only existing hardware can be used to achieve signal separation, eliminating frequency offset and phase noise, polarization state aliasing and intersymbol interference and other issues, effectively reducing the complexity of the optical millimeter-wave wireless system, thereby reducing the input cost of the optical millimeter-wave wireless system.

In one embodiment, the structure schematic diagram of the light-borne millimeter-wave receiving end can be shown in FIG. The demodulation sub-module 124 and the fourth demodulation sub-module 125 .

The first coupler 11 is connected with the rotation branching module 121, the first demodulation submodule 122 and the second demodulation submodule 123 of the demodulation module 12, and the rotation branching module 121 is also connected with the third demodulation submodule 124 and the second demodulation submodule 124. Four regulation sub-modules 125 are connected.

The rotation splitting module 121 is configured to rotate the polarization state of the local oscillator light in the third optical signal, and split the rotated third optical signal into a fourth optical signal and a fifth optical signal.

In a specific implementation, after the polarization state of the local oscillator light in the third optical signal is rotated, the rotated third optical signal is divided into the fourth optical signal and the fifth optical signal by the rotation branching module 121 To achieve this, the first coupler 11 can input the split third optical signal into the rotary branching module 121, and the rotary branching module 121 rotates the polarization state of the local oscillator light in the third optical signal by 90°, and the The rotated third optical signal is divided into a fourth optical signal and a fifth optical signal. The polarization state of the local oscillator light of the rotated third optical signal is the same as the polarization state of the second polarized signal light.

The first demodulation sub-module 122 is used to filter the lower sideband of the first optical signal, and capture the first radio frequency according to the local oscillator light and the first polarized signal light in the first optical signal after the lower sideband filtering Signal.

The second demodulation sub-module 123 is used to filter the upper sideband of the second optical signal, and capture the second radio frequency according to the local oscillator light and the first polarized signal light in the second optical signal after the upper sideband filtering Signal.

The third demodulation sub-module 124 is used to filter the lower sideband of the fourth optical signal, and capture the third radio frequency according to the local oscillator light and the second polarized signal light in the fourth optical signal after the lower sideband filtering Signal.

The fourth demodulation sub-module 125 is used to filter the upper sideband of the fifth optical signal, and capture the fourth radio frequency according to the local oscillator light and the second polarized signal light in the fifth optical signal after the upper sideband is filtered. Signal.

In a specific implementation, the four adjustment sub-modules of the adjustment module 12 can respectively process one radio frequency signal, since the optical signals processed by the third demodulation sub-module 124 and the fourth demodulation sub-module 125 are rotated For the optical signal obtained by splitting, the receiving end does not need to match the phase of the local oscillator light and the signal light, and is not easily affected by the phase change caused by the environment.

In one embodiment, the structural diagram of the optical-carrying millimeter-wave receiving end can be shown in FIG. mirror 1215, Faraday rotator mirror 1214 and second coupler 1216.

The first port of the optical circulator 1211 is connected to the first coupler 11, and the second port of the optical circulator 1211 is respectively connected to the first fiber mirror 1213, the second fiber mirror 1215 and the Faraday rotating mirror through the wavelength division multiplexer 1212. 1214, and the third port of the optical circulator 1211 is connected to the second coupler 1216.

In a specific implementation, after the first coupler 11 inputs the split third optical signal to the wavelength division multiplexer 1212 through the first port of the optical circulator 1211, the wavelength division multiplexer 1212 can combine the third optical signal The local oscillator light of the signal is separated from the signal light, the local oscillator light of the third optical signal is input to the Faraday rotating mirror 1214, and the signal light of the third optical signal is respectively input to the first optical fiber reflector 1213 and the second optical fiber reflector The mirror 1215 and the Faraday rotating mirror 1214 can rotate the polarization state of the local oscillator light of the third optical signal by 90°. The first optical fiber reflector 1213 and the second optical fiber reflective mirror 1215 do not have the rotation function and will not change the third optical signal. The polarization state of the signal light. When the local oscillator light of the third optical signal and the upper and lower sidebands of the signal light are wavelength division multiplexed and coupled again, the polarization state of the rotated local oscillator light is the same as that of the second polarized signal light, and is the same as that of the first polarized signal light. The polarization states of the polarized signal light are orthogonal. Using two fiber optic mirrors with a Faraday rotating mirror can accurately and quickly complete the task of rotating the shunt.

In one embodiment, a schematic structural diagram of an optical millimeter wave receiving end can be shown in FIG. 4 , the first sub-demodulation module 122 includes a first optical filter 1221 and a first photodetector connected to the first optical filter 1221 1222, the second sub-demodulation module 123 includes a second optical filter 1231 and a second photodetector 1232 connected to the second optical filter 1231, and the third sub-demodulation module 124 includes a third optical filter 1241 and a second photodetector 1232 connected to the second optical filter 1231. The third photodetector 1242 connected to the third optical filter 1241 , the fourth sub-demodulation module 125 includes a fourth optical filter 1251 and a fourth photodetector 1252 connected to the fourth optical filter 1251 .

The first optical filter 1221 is used to filter the lower sideband of the first optical signal.

The first photodetector 1222 is used to photograph the first radio frequency signal according to the local oscillator light and the first polarized signal light in the first optical signal after lower sideband filtering.

In a specific implementation, the first optical filter 1221 only allows the upper sideband of the signal light of the first optical signal and the local oscillator light to pass through, filters out the lower sideband of the signal light, and the upper sideband of the signal light of the first optical signal And the local oscillator light enters the first photodetector 1222, and the optical signal entering the photodetector 1222 at this time includes the local oscillator light, the upper sideband of the first polarized signal light and the upper sideband of the second polarized signal light, the local oscillator light and the first polarized signal light The first radio frequency signal can be photographed from the upper sideband of the first polarized signal light, but the radio frequency signal cannot be photographed because the polarization state of the local oscillator light is orthogonal to the polarization state of the upper sideband of the second polarized signal light.

The second optical filter 1231 is used to filter the upper sideband of the second optical signal.

The second photodetector 1232 is used to photograph the second radio frequency signal according to the local oscillator light and the first polarized signal light in the second optical signal after the upper sideband filtering.

In a specific implementation, the second optical filter 1231 only allows the lower sideband of the signal light of the second optical signal and the local oscillator light to pass through, filters out the upper sideband of the signal light, and the lower sideband of the signal light of the second optical signal And the local oscillator light enters the second photodetector 1232, and the optical signal entering the photodetector 1232 at this time includes the local oscillator light, the lower sideband of the first polarized signal light and the lower sideband of the second polarized signal light, the local oscillator light and the second polarized signal light The lower sideband of the first polarized signal light can capture the second radio frequency signal, but because the polarization state of the local oscillator light is orthogonal to the polarization state of the lower sideband of the second polarized signal light, the radio frequency signal cannot be captured.

The third optical filter 1241 is used to filter the lower sideband of the fourth optical signal.

The third photodetector 1242 is used to photograph the third radio frequency signal according to the local oscillator light and the second polarized signal light in the fourth optical signal after lower sideband filtering.

In a specific implementation, the third optical filter 1241 only allows the upper sideband of the signal light of the fourth optical signal and the local oscillator light to pass through, filters out the lower sideband of the signal light, and the upper sideband of the signal light of the fourth optical signal And the local oscillator light enters the third photodetector 1242, and the optical signal entering the photodetector 1242 at this time includes the local oscillator light, the upper sideband of the first polarized signal light and the upper sideband of the second polarized signal light, and the local oscillator light and the first polarized signal light The upper sideband of the two-polarized signal light can capture the third radio frequency signal. Since the polarization state of the local oscillator light is orthogonal to the polarization state of the upper sideband of the first polarized signal light, the radio frequency signal cannot be captured.

The fourth optical filter 1251 is used to filter the upper sideband of the fifth optical signal.

The fourth photodetector 1252 is used for photographing the fourth radio frequency signal according to the local oscillator light and the second polarized signal light in the fifth optical signal after upper sideband filtering.

In a specific implementation, the fourth optical filter 1251 only allows the lower sideband of the signal light of the fifth optical signal and the local oscillator light to pass through, filters out the upper sideband of the signal light, and the lower sideband of the signal light of the fifth optical signal And the local oscillator light enters the fourth photodetector 1252, and the optical signal entering the photodetector 1252 at this time includes the local oscillator light, the lower sideband of the first polarized signal light and the lower sideband of the second polarized signal light, the local oscillator light and the second polarized signal light The lower sideband of the two-polarized signal light can capture the fourth radio frequency signal. Since the polarization state of the local oscillator light is orthogonal to the polarization state of the lower sideband of the first polarized signal light, the radio frequency signal cannot be captured.

Another embodiment of the present application relates to an optical-carrying millimeter wave transmitting end. The implementation details of the optical-carrying millimeter-wave transmitting end of this embodiment are described in detail below, and the following content is only implementation details provided for easy understanding, and is not necessary for implementing this solution.

The schematic diagram of the light-borne millimeter wave transmitting end of this embodiment may be shown in FIG. 5 , including: a laser 13 , a third coupler 14 , a modulator 15 , a polarization controller 16 and a fourth coupler 17 .

The laser 13 is connected to the third coupler 14 , the third coupler 14 is connected to the modulator 15 and the polarization controller 16 , and both the modulator 15 and the polarization controller 16 are connected to the fourth coupler 17 .

The laser 13 is used to emit laser light.

The third coupler 14 is used to divide the laser light emitted by the laser 13 into a first path of light for carrying modulation signals and a second path of light as local oscillator light.

The modulator 15 is used to modulate the first radio frequency signal to the upper sideband of the first polarization state optical carrier of the first optical path, and modulate the second radio frequency signal to the lower sideband of the first polarization state optical carrier of the first optical path , to obtain the first polarized signal light carrying the modulated signal, and modulate the third radio frequency signal to the upper sideband of the second polarization state optical carrier of the first light, and modulate the fourth radio frequency signal to the second polarization state of the first light The lower sideband of the two-polarized optical carrier is used to obtain the second polarized signal light carrying the modulated signal.

In a specific implementation, the polarization state of the first polarized signal light is orthogonal to the polarization state of the second polarized signal light, and the modulator 15 completes the modulation of a total of four radio frequency signals, realizing the transmission of four independent signals on one optical carrier.

The polarization controller 16 is used to adjust the polarization state of the local oscillator light to be the same as that of the first polarized signal light.

The fourth coupler 17 is used to combine the first polarized signal light, the second polarized signal light and the local oscillator light, and input them into the optical fiber link for transmission.

Another embodiment of the present application relates to an optical millimeter wave wireless system. The implementation details of the optical-carrying millimeter-wave wireless system in this embodiment are described in detail below, and the following content is only the implementation details provided for the convenience of understanding, and is not necessary for the implementation of this solution. The schematic diagram of the optical-carrying millimeter-wave wireless system in this embodiment can be shown in FIG. modulation module 12 , the transmitting end includes a laser 13 , a third coupler 14 , a modulator 15 , a polarization controller 16 and a fourth coupler 17 .

It is worth mentioning that all the modules involved in the above embodiments are logical modules. In practical applications, a logical unit can be a physical unit, or a part of a physical unit, or multiple Composition of physical units. In addition, in order to highlight the innovative part of the present application, the above embodiments do not introduce units that are not closely related to solving the technical problems raised by the present application, but this does not mean that there are no other units in this embodiment.

Another embodiment of the present application relates to a method for demodulating optical-borne millimeter waves. The implementation details of the optical-borne millimeter-wave demodulation method in this embodiment are described in detail below, and the following content is only implementation details provided for easy understanding, and is not necessary for implementing this solution. The flow chart of the optical-borne millimeter-wave demodulation method in this embodiment may be shown in FIG. 7, including:

In step 201, the received optical signal is divided into a first optical signal, a second optical signal and a third optical signal.

In a specific implementation, each optical signal includes local oscillator light and signal light, the signal light includes first polarized signal light and second polarized signal light, the upper sideband of the first polarized signal light is modulated with the first radio frequency signal, and the second polarized signal light The lower sideband of a polarized signal light is modulated with a second radio frequency signal, the upper sideband of the second polarized signal light is modulated with a third radio frequency signal, the lower sideband of the second polarized signal light is modulated with a fourth radio frequency signal, and the first polarized signal light is modulated with a fourth radio frequency signal. The polarization state of the signal light is orthogonal to the polarization state of the second polarized signal light, and the polarization state of the local oscillator light is the same as that of the first polarized signal light.

Step 202: Rotate the polarization state of the local oscillator light in the third optical signal, and divide the rotated third optical signal into a fourth optical signal and a fifth optical signal.

Step 203, respectively filter out the lower sideband of the first optical signal, the upper sideband of the second optical signal, the lower sideband of the fourth optical signal, and the upper sideband of the fifth optical signal to obtain the first radio frequency signal, the second The second radio frequency signal, the third radio frequency signal and the fourth radio frequency signal.

It is not difficult to find that this embodiment is a method embodiment corresponding to the above embodiment of the optical-carrying millimeter-wave receiving end, and this embodiment can be implemented in cooperation with the above-mentioned optical-carrying millimeter-wave receiving end embodiment. The relevant technical details and technical effects mentioned in the above embodiments of the optical-carrier millimeter-wave receiving end are still valid in this embodiment, and will not be repeated here to reduce repetition. Correspondingly, the relevant technical details mentioned in this embodiment can also be applied to the above-mentioned embodiment of the optical-carrying millimeter-wave receiving end.

In one embodiment, the lower sideband of the first optical signal, the upper sideband of the second optical signal, the lower sideband of the fourth optical signal, and the upper sideband of the fifth optical signal are respectively filtered to obtain the first radio frequency The signal, the second radio frequency signal, the third radio frequency signal and the fourth radio frequency signal can be implemented by the steps shown in Figure 8, specifically including:

Step 301: Filter out the lower sideband of the first optical signal, and capture the first radio frequency signal according to the local oscillator light and the first polarized signal light in the first optical signal after the lower sideband filtering.

Step 302: Filter out the upper sideband of the second optical signal, and capture a second radio frequency signal according to the local oscillator light and the first polarized signal light in the second optical signal after the upper sideband filtering.

Step 303: Filter out the lower sideband of the fourth optical signal, and capture a third radio frequency signal according to the local oscillator light and the second polarized signal light in the fourth optical signal after the lower sideband filtering.

Step 304: Filter out the upper sideband of the fifth optical signal, and capture a fourth radio frequency signal according to the local oscillator light and the second polarized signal light in the fifth optical signal after the upper sideband filtering.

Another embodiment of the present application relates to an optical-carrying millimeter-wave modulation method. The implementation details of the optical-borne millimeter-wave modulation method in this embodiment will be described in detail below, and the following content is only implementation details provided for easy understanding, and is not necessary for implementing this solution. The flow chart of the optical-borne millimeter-wave modulation method in this embodiment may be shown in FIG. 9, including:

Step 401, divide the laser light emitted by the laser into a first path of light for carrying a modulation signal and a second path of light as local oscillator light.

Step 402, modulating the first radio frequency signal to the upper sideband of the first polarization state optical carrier of the first optical path, and modulating the second radio frequency signal to the lower sideband of the first polarization state optical carrier of the first optical path, The first polarized signal light carrying the modulated signal is obtained.

Step 403, modulating the third radio frequency signal to the upper sideband of the second polarization state optical carrier of the first optical path, and modulating the fourth radio frequency signal to the lower sideband of the second polarization state optical carrier of the first optical path, The second polarized signal light carrying the modulated signal is obtained.

Step 404, adjusting the polarization state of the local oscillator light to be the same as that of the first polarized signal light.

Step 405, after combining the first polarized signal light, the second polarized signal light and the local oscillator light, input them into the optical fiber link for transmission.

It is not difficult to find that this embodiment is a method embodiment corresponding to the above-mentioned embodiment of the optical-carrying millimeter-wave transmitting end, and this embodiment can be implemented in cooperation with the above-mentioned embodiment of the optical-carrying millimeter-wave transmitting end. The relevant technical details and technical effects mentioned in the above embodiments of the optical-carrier millimeter-wave transmitting end are still valid in this embodiment, and will not be repeated here to reduce repetition. Correspondingly, the relevant technical details mentioned in this embodiment can also be applied to the above-mentioned embodiment of the millimeter wave transmitting end over optical.

Those of ordinary skill in the art can understand that the above-mentioned embodiments are specific embodiments for realizing the present application, and in practical applications, various changes can be made to it in form and details without departing from the spirit and spirit of the present application. scope.

Claims

An optical carrier millimeter wave receiving end, comprising:

The first coupler is used to divide the received optical signal into the first optical signal, the second optical signal and the third optical signal; wherein, each optical signal includes local oscillator light and signal light, and the signal The light includes first polarized signal light and second polarized signal light, the upper sideband of the first polarized signal light is modulated with a first radio frequency signal, and the lower sideband of the first polarized signal light is modulated with a second radio frequency signal, The upper sideband of the second polarized signal light is modulated with a third radio frequency signal, the lower sideband of the second polarized signal light is modulated with a fourth radio frequency signal, and the polarization state of the first polarized signal light is the same as that of the first polarized signal light. The polarization states of the two polarized signal lights are orthogonal, and the polarization state of the local oscillator light is the same as the polarization state of the first polarized signal light;

a demodulation module, configured to rotate the polarization state of the local oscillator light in the third optical signal, and divide the rotated third optical signal into a fourth optical signal and a fifth optical signal, and by filtering out the lower sideband of the first optical signal, the upper sideband of the second optical signal, the lower sideband of the fourth optical signal, and the upper sideband of the fifth optical signal, to obtain The first radio frequency signal, the second radio frequency signal, the third radio frequency signal, and the fourth radio frequency signal; wherein, the polarization state of the local oscillator light after rotation is the same as that of the second radio frequency signal The polarization states of the polarized signal lights are the same.
The optical-carrying millimeter-wave receiving terminal according to claim 1, wherein the demodulation module includes:

A rotation splitting module, configured to rotate the polarization state of the local oscillator light in the third optical signal, and split the rotated third optical signal into a fourth optical signal and a fifth optical signal .
The optical-carrying millimeter-wave receiving end according to claim 2, wherein the demodulation module further comprises:

The first demodulation sub-module is configured to filter out the lower sideband of the first optical signal, and shoot out the local oscillator light and the first polarized signal light in the first optical signal after filtering out the lower sideband The first radio frequency signal;

The second demodulation sub-module is configured to filter out the upper sideband of the second optical signal, and shoot out the local oscillator light and the first polarized signal light in the second optical signal after filtering out the upper sideband The second radio frequency signal;

The third demodulation sub-module is configured to filter out the lower sideband of the fourth optical signal, and shoot out the local oscillator light and the second polarized signal light in the fourth optical signal after filtering out the lower sideband The third radio frequency signal;

The fourth demodulation sub-module is configured to filter out the upper sideband of the fifth optical signal, and shoot out the local oscillator light and the second polarized signal light in the fifth optical signal after filtering out the upper sideband The fourth radio frequency signal.
The optical-carrying millimeter-wave receiving end according to any one of claims 2 to 3, wherein the rotary branching module includes: an optical circulator, a wavelength division multiplexer, a first fiber optic reflector, a second fiber reflector mirror, Faraday rotating mirror, second coupler;

The first port of the optical circulator is connected to the first coupler, and the second port of the optical circulator is respectively connected to the first optical fiber mirror and the second optical fiber through the wavelength division multiplexer. The reflection mirror is connected to the Faraday rotating mirror, and the third port of the optical circulator is connected to the second coupler.
The optical-carrying millimeter-wave receiving terminal according to any one of claims 3 to 4, wherein the first demodulation sub-module includes: a first optical filter and a first optical filter connected to the first optical filter Photodetector;

The first optical filter is used to filter out the lower sideband of the first optical signal;

The first photodetector is used to capture the first radio frequency signal according to the local oscillator light and the first polarized signal light in the first optical signal after lower sideband filtering;

The second demodulation submodule includes: a second optical filter and a second photodetector connected to the second optical filter;

The second optical filter is used to filter out the upper sideband of the second optical signal;

The second photodetector is used to capture the second radio frequency signal according to the local oscillator light and the first polarized signal light in the second optical signal after upper sideband filtering;

The third demodulation submodule includes: a third optical filter and a third photodetector connected to the third optical filter;

The third optical filter is used to filter out the lower sideband of the fourth optical signal;

The third photodetector is used to capture the third radio frequency signal according to the local oscillator light and the second polarized signal light in the fourth optical signal after lower sideband filtering;

The fourth demodulation submodule includes: a fourth optical filter and a fourth photodetector connected to the fourth optical filter;

The fourth optical filter is used to filter out the upper sideband of the fifth optical signal;

The fourth photodetector is used to capture the fourth radio frequency signal according to the local oscillator light and the second polarized signal light in the fifth optical signal after upper sideband filtering.
An optical carrier millimeter wave transmitting end, comprising: a laser, a third coupler, a modulator, a polarization controller, and a fourth coupler; the laser is connected to the third coupler, and the third coupler is connected to the The modulator is connected to the polarization controller, and both the modulator and the polarization controller are connected to the fourth coupler;

The laser is used to emit laser light;

The third coupler is used to divide the laser light emitted by the laser into a first path of light for carrying a modulation signal and a second path of light as local oscillator light;

The modulator is used to modulate the first radio frequency signal to the upper sideband of the first polarization state of the first light carrier, and modulate the second radio frequency signal to the first polarization state of the first light the lower sideband of the carrier to obtain the first polarized signal light carrying the modulated signal; and modulate the third radio frequency signal to the upper sideband of the second polarization state optical carrier of the first light, and modulate the fourth radio frequency signal to The lower sideband of the second polarization state optical carrier of the first path of light obtains the second polarized signal light carrying the modulation signal; wherein, the polarization state of the first polarized signal light is different from the polarization of the second polarized signal light Orthogonal state;

The polarization controller is used to adjust the polarization state of the local oscillator light to be the same as the polarization state of the first polarized signal light;

The fourth coupler is configured to combine the first polarized signal light, the second polarized signal light and the local oscillator light, and input them into an optical fiber link for transmission.
An optical-carrying millimeter-wave wireless system, comprising the optical-carrying millimeter-wave receiving end as claimed in any one of claims 1 to 5, and the optical-carrying millimeter-wave transmitting end as claimed in claim 6.
A method for demodulating light-borne millimeter waves, comprising:

Dividing the received optical signal into a first optical signal, a second optical signal and a third optical signal; wherein each optical signal includes local oscillator light and signal light, and the signal light includes first polarized signal light and the second polarized signal light, the upper sideband of the first polarized signal light is modulated with a first radio frequency signal, the lower sideband of the first polarized signal light is modulated with a second radio frequency signal, and the second polarized signal light The upper sideband of the second polarized signal light is modulated with a third radio frequency signal, the lower sideband of the second polarized signal light is modulated with a fourth radio frequency signal, the polarization state of the first polarized signal light is different from the polarization state of the second polarized signal light Orthogonal, the polarization state of the local oscillator light is the same as the polarization state of the first polarized signal light;

Rotating the polarization state of the local oscillator light in the third optical signal, and dividing the rotated third optical signal into a fourth optical signal and a fifth optical signal; wherein, the rotated The polarization state of the local oscillator light is the same as the polarization state of the second polarized signal light;

respectively filtering out the lower sideband of the first optical signal, the upper sideband of the second optical signal, the lower sideband of the fourth optical signal, and the upper sideband of the fifth optical signal to obtain the The first radio frequency signal, the second radio frequency signal, the third radio frequency signal, and the fourth radio frequency signal.
The optical carrier millimeter wave demodulation method according to claim 8, wherein said respectively filtering out the lower sideband of the first optical signal, the upper sideband of the second optical signal, and the fourth optical signal the lower sideband of the signal and the upper sideband of the fifth optical signal, and obtain the first radio frequency signal, the second radio frequency signal, the third radio frequency signal and the fourth radio frequency signal, including :

filtering the lower sideband of the first optical signal, and photographing the first radio frequency signal according to the local oscillator light and the first polarized signal light in the first optical signal after the lower sideband filtering;

filtering the upper sideband of the second optical signal, and photographing the second radio frequency signal according to the local oscillator light and the first polarized signal light in the second optical signal after the upper sideband filtering;

filtering the lower sideband of the fourth optical signal, and photographing the third radio frequency signal according to the local oscillator light and the second polarized signal light in the fourth optical signal after the lower sideband filtering;

The upper sideband of the fifth optical signal is filtered, and the fourth radio frequency signal is captured according to the local oscillator light and the second polarized signal light in the fifth optical signal after the upper sideband is filtered.
An optical carrier millimeter wave modulation method, comprising:

Divide the laser light emitted by the laser into the first path of light used to carry the modulation signal and the second path of light as the local oscillator light;

modulating the first radio frequency signal to the upper sideband of the first polarization state optical carrier of the first light, and modulating the second radio frequency signal to the lower sideband of the first polarization state optical carrier of the first light , to obtain the first polarized signal light carrying the modulation signal;

modulating the third radio frequency signal to the upper sideband of the second polarization state optical carrier of the first optical path, and modulating the fourth radio frequency signal to the lower sideband of the second polarization state optical carrier of the first optical path , to obtain the second polarized signal light carrying the modulation signal;

adjusting the polarization state of the local oscillator light to be the same as the polarization state of the first polarized signal light;

After combining the first polarized signal light, the second polarized signal light and the local oscillator light, they are input into an optical fiber link for transmission.