CN118138143A - Photon terahertz communication sensing system and method - Google Patents

Abstract

The present invention provides a photon terahertz communication sensing system and method, the photon terahertz communication sensing system comprises: a first high-speed photoelectric detector performs heterodyne beat frequency on a first coupled signal to obtain a terahertz synaesthesia signal; a second high-speed photoelectric detector performs heterodyne beat frequency on a second coupled signal to obtain a reference terahertz local oscillator signal, the terahertz synaesthesia signal and the reference terahertz local oscillator signal have the same frequency offset, the first coupled signal and the second coupled signal are both obtained based on an optical carrier signal and an optical local oscillator signal, and the first coupled signal and the second coupled signal are different; a user unit determines a first radar echo signal according to the terahertz synaesthesia signal; a terahertz mixing module determines a target radar echo signal according to the reference terahertz local oscillator signal and the first radar echo signal. The system can effectively eliminate the frequency deviation and phase noise caused by the heterodyne beat frequency, thereby improving the radar detection accuracy.

Description

Photonic terahertz communication sensing system and method

Technical Field

The present invention relates to the field of signal processing technology, and in particular to a photonic terahertz communication sensing system and method.

Background technique

As wireless communication and radar technologies develop towards higher frequency bands, the operating frequencies of communication transmission and radar perception overlap in the terahertz band. In the terahertz band, wider bandwidth and smaller antenna arrays make it possible to simultaneously achieve larger capacity communications and higher precision perception. At present, the rich spectrum resources in the terahertz band have not yet been allocated. The Integrated Sensing and Communication (ISAC) function can be verified in the terahertz band, so that communication and perception functions complement each other and serve the future terahertz era of the sixth generation wireless systems (6G). In addition, integrating communication and radar in the same system has the characteristics of simplifying the system structure, reducing hardware costs, and reducing electromagnetic interference between communication and radar. Photonics technology has the characteristics of high operating frequency, large instantaneous bandwidth, and strong anti-electromagnetic interference ability. Photonics technology is widely used in wireless communications and radar imaging.

The existing photonic terahertz communication perception method uses two free lasers to generate terahertz communication perception signals (abbreviated as terahertz synaesthesia signals). The frequency of the terahertz synaesthesia signals is flexibly adjustable and suitable for remote systems with separated optical carriers and optical local oscillators. However, this method will have relatively serious frequency offset (abbreviated as frequency deviation) and phase noise (abbreviated as phase noise), which will lead to low radar detection accuracy.

Summary of the invention

The present invention provides a photon terahertz communication sensing system and method, which are used to solve the defect that the existing photon terahertz communication sensing method has relatively serious frequency deviation and phase noise, thereby resulting in low radar detection accuracy. The terahertz synaesthesia signal and the reference terahertz local oscillator signal generated in the photon terahertz communication sensing system have the same frequency deviation. After the user unit determines the first radar echo signal according to the terahertz synaesthesia signal, the terahertz mixing module performs mixing correlation processing on the reference terahertz local oscillator signal and the first radar echo signal. The frequency deviations of the two signals will cancel each other, and the frequency deviation and phase noise caused by the heterodyne beat frequency can be effectively eliminated, thereby improving the radar detection accuracy.

In a first aspect, the present invention provides a photonic terahertz communication sensing system, comprising: a remote unit and a user unit, wherein the remote unit comprises: a first high-speed photodetector, a second high-speed photodetector and a terahertz mixing module, and the system comprises:

The first high-speed photodetector is used to perform heterodyne beat frequency on the first coupled signal to obtain a terahertz synaesthesia signal;

The second high-speed photodetector is used to perform heterodyne beat frequency on the second coupled signal to obtain a reference terahertz local oscillator signal, the terahertz synaesthesia signal and the reference terahertz local oscillator signal have the same frequency offset, the first coupled signal and the second coupled signal are both obtained based on the optical carrier signal and the optical local oscillator signal, and the first coupled signal and the second coupled signal are different;

The user unit is used to determine a first radar echo signal according to the terahertz synaesthesia signal;

The terahertz mixing module is used to determine the target radar echo signal according to the reference terahertz local oscillator signal and the first radar echo signal.

A photonic terahertz communication perception system provided by the present invention also includes a central unit, which includes a modulated light determination module; the remote unit also includes: a beam splitting module, a first laser, a first polarization-maintaining fiber coupler and a first coupling module; the beam splitting module is used to determine a downlink optical signal according to the modulated light signal generated by the modulated light determination module, and the modulated light signal is an asymmetric optical single-sideband signal containing an optical carrier; the first polarization-maintaining fiber coupler is used to determine a first sub-optical local oscillator signal according to the optical local oscillator signal generated by the first laser; the first coupling module is used to determine the first coupling signal according to the downlink optical signal and the first sub-optical local oscillator signal.

According to a photonic terahertz communication perception system provided by the present invention, the user unit includes: a terahertz envelope detection module and a communication signal processing module; the terahertz envelope detection module is used to determine a first intermediate frequency synaesthesia signal according to the terahertz synaesthesia signal; the communication signal processing module is used to determine communication information according to the first intermediate frequency synaesthesia signal.

According to a photonic terahertz communication perception system provided by the present invention, the first coupling module includes a second polarization-maintaining fiber coupler, a first erbium-doped fiber amplifier and a first variable optical attenuator; the second polarization-maintaining fiber coupler is used to determine the first signal according to the downlink optical signal and the first sub-optical local oscillator signal; the first erbium-doped fiber amplifier is used to amplify the optical power of the first signal to determine the second signal; the first variable optical attenuator is used to optimize the optical power of the second signal to obtain the first coupled signal.

A photonic terahertz communication perception system provided by the present invention also includes a central unit, which includes a modulated light determination module; the remote unit also includes: a beam splitting module, a first optical bandpass filter, a first laser, a first polarization-maintaining fiber coupler and a second coupling module; the beam splitting module is used to determine a first reference optical signal according to the modulated light signal generated by the modulated light determination module, and the modulated light signal is an asymmetric optical single-sideband signal containing an optical carrier; the first optical bandpass filter is used to filter the first reference optical signal to obtain a target optical carrier signal; the first polarization-maintaining fiber coupler is used to determine a second sub-optical local oscillator signal according to the optical local oscillator signal generated by the first laser; the second coupling module is used to determine the second coupling signal according to the target optical carrier signal and the second sub-optical local oscillator signal.

According to a photonic terahertz communication perception system provided by the present invention, the second coupling module includes a third polarization-maintaining fiber coupler, a second erbium-doped fiber amplifier and a second variable optical attenuator; the third polarization-maintaining fiber coupler is used to determine a third signal according to the target optical carrier signal and the second sub-optical local oscillator signal; the second erbium-doped fiber amplifier is used to amplify the optical power of the third signal to determine a fourth signal; the second variable optical attenuator is used to optimize the optical power of the fourth signal to obtain the second coupled signal.

According to a photonic terahertz communication perception system provided by the present invention, the modulated light determination module includes: a second laser, a transmitting end signal processing unit, a digital-to-analog converter, a first electro-optical modulator and a first circulator; the digital-to-analog converter is used to determine the second synaesthesia signal according to the first synaesthesia signal generated by the transmitting end signal processing unit; the first electro-optical modulator is used to determine the modulated light signal according to the second synaesthesia signal and the optical carrier signal generated by the second laser; the first circulator is used to transmit the modulated light signal to the beam splitting module.

According to a photonic terahertz communication perception system provided by the present invention, the beam splitting module includes: a second circulator, a third erbium-doped fiber amplifier, a polarization controller and a polarization-maintaining beam splitter; the second circulator is used to receive the modulated light signal transmitted by the modulated light determination module; the third erbium-doped fiber amplifier is used to amplify the optical power of the modulated light signal to determine the first modulated light signal; the polarization controller is used to perform polarization processing on the first modulated light signal to obtain a second modulated light signal; the polarization-maintaining beam splitter is used to perform beam splitting processing on the second modulated light signal to obtain the downlink light signal.

According to a photonic terahertz communication perception system provided by the present invention, the terahertz mixing module includes: a first terahertz low-noise power amplifier, a second terahertz low-noise power amplifier and a terahertz mixer; the first terahertz low-noise power amplifier is used to power amplify the reference terahertz local oscillator signal to obtain a target reference terahertz local oscillator signal; the second terahertz low-noise power amplifier is used to power amplify the first radar echo signal to obtain a second radar echo signal; the terahertz mixer is used to mix the target reference terahertz local oscillator signal and the second radar echo signal to obtain the target radar echo signal.

According to a photonic terahertz communication perception system provided by the present invention, the terahertz envelope detection module includes: a third terahertz low-noise power amplifier and a terahertz envelope detector; the communication signal processing module includes: a first intermediate frequency low-noise power amplifier, an electrical bandpass filter, a first analog-to-digital converter and a communication signal processing unit; the third terahertz low-noise power amplifier is used to power amplify the terahertz synaesthesia signal to obtain a fifth signal; the terahertz envelope detector is used to perform envelope detection on the fifth signal to obtain the first intermediate frequency synaesthesia signal; the first intermediate frequency low-noise power amplifier is used to power amplify the first intermediate frequency synaesthesia signal to obtain a second intermediate frequency synaesthesia signal; the electrical bandpass filter is used to filter the second intermediate frequency synaesthesia signal to obtain a first communication signal; the first analog-to-digital converter is used to perform analog-to-digital conversion on the first communication signal to obtain a second communication signal; and the communication signal processing unit is used to process the second communication signal to obtain the communication information.

According to a photonic terahertz communication perception system provided by the present invention, the remote unit also includes: an electro-optical modulation module; the central unit also includes: a perception signal processing module; the electro-optical modulation module is used to determine the target echo electro-optical modulation signal according to the target radar echo signal; the perception signal processing module is used to determine the terminal-related information of the user unit according to the target echo electro-optical modulation signal.

According to a photonic terahertz communication perception system provided by the present invention, the electro-optical modulation module includes: a second intermediate frequency low noise power amplifier, a second electro-optical modulator, a fourth erbium-doped fiber amplifier and a second optical bandpass filter; the beam splitting module is also used to determine a second reference optical signal according to the modulated optical signal; the second intermediate frequency low noise power amplifier is used to amplify the power of the target radar echo signal to obtain a third radar echo signal; the second electro-optical modulator is used to determine a first echo electro-optical modulation signal according to the third radar echo signal and the second reference optical signal; the fourth erbium-doped fiber amplifier is used to amplify the optical power of the first echo electro-optical modulation signal to obtain a second echo electro-optical modulation signal; the second optical bandpass filter is used to filter the second echo electro-optical modulation signal to obtain the target echo electro-optical modulation signal.

According to a photonic terahertz communication perception system provided by the present invention, the perception signal processing module includes: a low-speed photodetector, a third intermediate frequency low-noise power amplifier, a second analog-to-digital converter and a perception signal processing unit; the low-speed photodetector is used to perform beat frequency de-chirping on the target echo electro-optical modulation signal to obtain an electrical intermediate frequency perception signal; the third intermediate frequency low-noise power amplifier is used to perform power amplification on the electrical intermediate frequency perception signal to obtain a first electrical intermediate frequency perception signal; the second analog-to-digital converter is used to perform analog-to-digital conversion on the first electrical intermediate frequency perception signal to obtain a second electrical intermediate frequency perception signal; the perception signal processing unit is used to process the second electrical intermediate frequency perception signal to obtain the terminal related information.

In a second aspect, the present invention provides a photon terahertz communication sensing method, which is applied to the photon terahertz communication sensing system according to any one of the first aspects, wherein the photon terahertz communication sensing system comprises a remote unit and a user unit, wherein the remote unit comprises: a first high-speed photodetector, a second high-speed photodetector and a terahertz mixing module, and the method comprises:

Using the first high-speed photodetector to perform heterodyne beat frequency on the first coupled signal to obtain a terahertz synaesthesia signal;

The second high-speed photodetector is used to perform heterodyne beat frequency on the second coupled signal to obtain a reference terahertz local oscillator signal, wherein the terahertz synaesthesia signal and the reference terahertz local oscillator signal have the same frequency offset, the first coupled signal and the second coupled signal are both obtained based on an optical carrier signal and an optical local oscillator signal, and the first coupled signal and the second coupled signal are different;

Determining a first radar echo signal using the user unit according to the terahertz synaesthesia signal;

The terahertz mixing module is used to determine the target radar echo signal according to the reference terahertz local oscillator signal and the first radar echo signal.

The present invention provides a photon terahertz communication sensing system and method. The photon terahertz communication sensing system comprises a remote unit and a user unit. The remote unit comprises: a first high-speed photodetector, a second high-speed photodetector and a terahertz mixing module. The system comprises: the first high-speed photodetector, which is used to perform heterodyne beat frequency on a first coupled signal to obtain a terahertz synaesthesia signal; the second high-speed photodetector, which is used to perform heterodyne beat frequency on a second coupled signal to obtain a reference terahertz local oscillator signal, the terahertz synaesthesia signal and the reference terahertz local oscillator signal have the same frequency offset, the first coupled signal and the second coupled signal are both obtained based on an optical carrier signal and an optical local oscillator signal, and the first coupled signal and the second coupled signal are different; the user unit, which is used to determine a first radar echo signal according to the terahertz synaesthesia signal; and the terahertz mixing module, which is used to determine a target radar echo signal according to the reference terahertz local oscillator signal and the first radar echo signal. The terahertz synaesthesia signal and the reference terahertz local oscillator signal generated in the photonic terahertz communication sensing system have the same frequency deviation. After the user unit determines the first radar echo signal according to the terahertz synaesthesia signal, the terahertz mixing module will perform mixing correlation processing on the reference terahertz local oscillator signal and the first radar echo signal. The frequency deviations of the two signals will cancel each other out, which can effectively eliminate the frequency deviation and phase noise caused by the heterodyne beat frequency, thereby improving the radar detection accuracy.

BRIEF DESCRIPTION OF THE DRAWINGS

In order to more clearly illustrate the technical solutions in the present invention or the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

FIG1 is a schematic diagram of a structure of a photonic terahertz communication sensing system provided by the present invention;

FIG2 is a schematic diagram of a structure of a remote unit provided by the present invention;

FIG3 is a second schematic diagram of the structure of the remote unit provided by the present invention;

FIG4 is a schematic diagram of a structure of a user unit provided by the present invention;

FIG5 is a schematic diagram of the structure of a terahertz mixing module provided by the present invention;

FIG6 is a second structural schematic diagram of the photonic terahertz communication sensing system provided by the present invention;

FIG7 is a schematic structural diagram of a first coupling module provided by the present invention;

FIG8 is a third structural schematic diagram of the photonic terahertz communication sensing system provided by the present invention;

FIG9 is a schematic structural diagram of a second coupling module provided by the present invention;

10 is a schematic diagram of the structure of a modulated light determination module provided by the present invention;

FIG11 is a schematic structural diagram of a beam splitting module provided by the present invention;

12 is a schematic diagram of the structure of the user unit provided by the present invention;

FIG13 is a schematic structural diagram of a terahertz envelope detection module provided by the present invention;

14 is a schematic diagram of the structure of a communication signal processing module provided by the present invention;

FIG15 is a third schematic diagram of the structure of the remote unit provided by the present invention;

FIG16 is a schematic structural diagram of a central unit provided by the present invention;

FIG17 is a schematic diagram of the structure of an electro-optical modulation module provided by the present invention;

FIG18 is a schematic diagram of the structure of a perception signal processing module provided by the present invention;

FIG19 is a fourth structural schematic diagram of the photonic terahertz communication sensing system provided by the present invention;

FIG20 is a schematic diagram of optical spectra and electrical spectra of different nodes of the photonic terahertz communication sensing system provided by the present invention;

FIG21 is a flow chart of the photonic terahertz communication sensing method provided by the present invention.

Detailed ways

In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the drawings of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

The embodiments of the present invention are further described below.

As shown in FIG1 , it is a schematic diagram of the structure of the photon terahertz communication sensing system provided by the present invention. The photon terahertz communication sensing system comprises: a remote unit 10 and a user unit 20, the remote unit 10 comprises: a first high-speed photodetector 101, a second high-speed photodetector 102 and a terahertz mixing module 103, and the system comprises:

A first high-speed photodetector 101, used for performing heterodyne beat frequency on the first coupled signal to obtain a terahertz synaesthesia signal;

A second high-speed photodetector 102 is used to perform heterodyne beat frequency on the second coupled signal to obtain a reference terahertz local oscillator signal, the terahertz synaesthesia signal and the reference terahertz local oscillator signal have the same frequency offset, the first coupled signal and the second coupled signal are both obtained based on the optical carrier signal and the optical local oscillator signal, and the first coupled signal and the second coupled signal are different;

The user unit 20 is used to determine the first radar echo signal according to the terahertz synaesthesia signal;

The terahertz mixing module 103 is used to determine the target radar echo signal according to the reference terahertz local oscillator signal and the first radar echo signal.

The user unit 20 is also called a communication receiver (Communication Receiver, Com. Receiver).

Terahertz synaesthesia signal is also called downlink terahertz synaesthesia signal.

The first radar echo signal is also called the uplink terahertz synaesthesia signal.

An optical carrier signal is a signal that uses light waves as information carriers for transmission.

The optical local oscillator signal is a stable light source signal used to modulate the optical signal.

In the embodiment of the present invention, after receiving the first coupling signal, the first high-speed photodetector 101 performs heterodyne beat frequency on the first coupling signal to generate a terahertz synaesthesia signal; after receiving the second coupling signal, the second high-speed photodetector 102 performs heterodyne beat frequency on the second coupling signal to generate a reference terahertz local oscillator signal, and the frequency deviation of the reference terahertz local oscillator signal is the same as the frequency deviation of the terahertz synaesthesia signal; the user unit 20 can determine the first radar echo signal according to the terahertz synaesthesia signal; the terahertz mixing module 103 performs mixing correlation processing on the reference terahertz local oscillator signal and the first radar echo signal to obtain a target radar echo signal. During the whole process, since the frequency deviation of the reference terahertz local oscillator signal is the same as the frequency deviation of the terahertz synaesthesia signal, and the first radar echo signal is obtained based on the terahertz synaesthesia signal, in the process of mixing the reference terahertz local oscillator signal and the first radar echo signal, the frequency deviations of the reference terahertz local oscillator signal and the first radar echo signal can be offset each other, which can effectively eliminate the frequency deviation and phase noise caused by the heterodyne beat frequency, thereby improving the radar detection accuracy.

It should be noted that the timing of the first high-speed photodetector 101 determining the terahertz synaesthesia signal and the second high-speed photodetector 102 determining the reference terahertz local oscillation signal is not limited.

Optionally, as shown in FIG2 , it is a schematic diagram of the structure of the remote unit provided by the present invention. The remote unit 10 may further include a terahertz power amplifier 104 and a first antenna 105 .

After the first high-speed photodetector 101 determines the terahertz synaesthesia signal, the terahertz power amplifier 104 amplifies the power of the terahertz synaesthesia signal to effectively increase the signal energy of the terahertz synaesthesia signal. The amplified terahertz synaesthesia signal is suitable for long-distance transmission. The first antenna 105 then radiates the amplified terahertz synaesthesia signal into the air so that the user unit 20 can receive it.

Optionally, as shown in FIG3 , it is a schematic diagram of the structure of the remote unit provided by the present invention. The remote unit 10 may further include a third antenna 106 .

Optionally, as shown in FIG4 , it is a schematic diagram of the structure of a subscriber unit provided by the present invention. The subscriber unit 20 may include a second antenna 201 .

In conjunction with Figures 2, 3 and 4, the second antenna 201 receives the amplified terahertz synaesthesia signal sent by the first antenna 105 from the air, and reflects the amplified terahertz synaesthesia signal to the third antenna 106. At this time, the reflected signal received by the third antenna 106 is the uplink terahertz synaesthesia signal, that is, the first radar echo signal. The signal transmission between the first antenna 105 and the second antenna 201, and between the second antenna 201 and the third antenna 106 meets the wireless communication requirements between the remote unit 10 and the user unit 20.

Optionally, in the process of the user unit 20 reflecting the signal to the remote unit 10, the second antenna 201 in the user unit 20 may reflect the terahertz synaesthesia signal to the remote unit 10, or the terminal device body or other parts of the user unit 20 may reflect the terahertz synaesthesia signal to the remote unit 10.

In some embodiments, as shown in FIG5 , it is a schematic diagram of the structure of the terahertz mixing module provided by the present invention. The terahertz mixing module 103 includes: a first terahertz low noise power amplifier 1031, a second terahertz low noise power amplifier 1032 and a terahertz mixer 1033;

A first terahertz low-noise power amplifier 1031 is used to amplify the power of the reference terahertz local oscillator signal to obtain a target reference terahertz local oscillator signal;

A second terahertz low-noise power amplifier 1032 is used to amplify the power of the first radar echo signal to obtain a second radar echo signal;

The terahertz mixer 1033 is used to mix the target reference terahertz local oscillator signal and the second radar echo signal to obtain the target radar echo signal.

Optionally, the above-mentioned mixing method can be down conversion.

In an embodiment of the present invention, after receiving the first radar echo signal reflected by the second antenna 201, the third antenna 106 transmits the first radar echo signal to the second terahertz low-noise power amplifier 1032 for power amplification to obtain a second radar echo signal, the signal quality of the second radar echo signal is good and the fidelity is high, and the second terahertz low-noise power amplifier 1032 transmits the second radar echo signal to the terahertz mixer 1033; at the same time, the second high-speed photodetector 102 transmits the generated reference terahertz local oscillator signal to the first terahertz low-noise power amplifier 1031 for power amplification to obtain a target reference terahertz local oscillator signal, the signal quality of the target reference terahertz local oscillator signal is good and the fidelity is high, and the first terahertz low-noise power amplifier 1031 transmits the target reference terahertz local oscillator signal to the terahertz mixer 1033. Based on this, the terahertz mixer 1033 mixes the target reference terahertz local oscillator signal and the second radar echo signal, down-converts the second radar echo signal to an intermediate frequency, and obtains the target radar echo signal. In the whole process, since the frequency deviation of the reference terahertz local oscillator signal is the same as the frequency deviation of the terahertz synaesthesia signal, and the target reference terahertz local oscillator signal is obtained based on the reference terahertz local oscillator signal, and the second radar echo signal is obtained based on the terahertz synaesthesia signal, in the process of mixing the target reference terahertz local oscillator signal and the second radar echo signal, the frequency deviations of the target reference terahertz local oscillator signal and the second radar echo signal will cancel each other, which can effectively eliminate the frequency deviation and phase noise caused by the heterodyne beat frequency, and realize the low frequency deviation and low phase noise down-conversion of the multi-channel radar echo signal.

In some embodiments, as shown in FIG6 , it is a schematic diagram of the structure of the photon terahertz communication sensing system provided by the present invention. The photon terahertz communication sensing system further includes a central unit 30, the central unit 30 includes a modulated light determination module 301; the remote unit 10 further includes: a beam splitting module 107, a first laser 108, a first polarization-maintaining fiber coupler 109 and a first coupling module 110;

The beam splitting module 107 is used to determine the downlink optical signal according to the modulated optical signal generated by the modulated optical determination module 301, where the modulated optical signal is an asymmetric optical single sideband signal containing an optical carrier;

A first polarization-maintaining fiber coupler 109, configured to determine a first sub-optical local oscillator signal according to the optical local oscillator signal generated by the first laser 108;

The first coupling module 110 is configured to determine a first coupling signal according to the downlink optical signal and the first sub-optical local oscillator signal.

In the embodiment of the present invention, after generating the modulated optical signal, the modulated optical determination module 301 transmits the modulated optical signal to the beam splitting module 107 through the single-mode optical fiber to achieve the distance of the modulated optical signal. After receiving the modulated optical signal, the beam splitting module 107 performs beam splitting correlation processing on the modulated optical signal to obtain a downlink optical signal, and transmits the downlink optical signal to the first coupling module 110; at the same time, the first laser 108 generates an optical local oscillator signal, and transmits the optical local oscillator signal to the first polarization-maintaining fiber coupler 109; the optical local oscillator signal is divided into two signals by the first polarization-maintaining fiber coupler 109, one of which is the first sub-optical local oscillator signal, and the first sub-optical local oscillator signal is transmitted to the first coupling module 110. Based on this, the first coupling module 110 performs coupling correlation processing on the downlink optical signal and the first sub-optical local oscillator signal to obtain a first coupling signal, which carries the processed downlink optical signal and the first sub-optical local oscillator signal, and provides effective data information for generating a terahertz synaesthesia signal.

It should be noted that the wavelength of the optical local oscillator signal generated by the first laser 108 is adjustable, and the frequency of the terahertz synaesthesia signal generated by the first high-speed photodetector 101 is flexibly controllable.

In some embodiments, as shown in Fig. 7, it is a schematic diagram of the structure of the first coupling module provided by the present invention. The first coupling module 110 includes a second polarization-maintaining fiber coupler 1101, a first erbium-doped fiber amplifier 1102 and a first variable optical attenuator 1103;

The second polarization-maintaining fiber coupler 1101 is used to determine the first signal according to the downlink optical signal and the first sub-optical local oscillator signal;

A first erbium-doped fiber amplifier 1102, used to amplify the optical power of the first signal to determine the second signal;

The first variable optical attenuator 1103 is used to optimize the optical power of the second signal to obtain a first coupled signal.

In an embodiment of the present invention, after the second polarization-maintaining fiber coupler 1101 receives the downlink optical signal transmitted by the beam splitting module 107 and receives the first sub-optical local oscillator signal transmitted by the first polarization-maintaining fiber coupler 109, the second polarization-maintaining fiber coupler 1101 couples the downlink optical signal and the first sub-optical local oscillator signal to obtain a first signal, and transmits the first signal to the first erbium-doped fiber amplifier 1102 for optical power amplification to obtain a second signal, the second signal having good signal quality and high fidelity; the first erbium-doped fiber amplifier 1102 transmits the second signal to the first variable optical attenuator 1103 for optical power optimization to further improve the signal quality and fidelity of the second signal to obtain a first coupled signal, the first coupled signal carrying the processed downlink optical signal and the first sub-optical local oscillator signal, and providing effective data information for generating a terahertz synaesthesia signal.

In some embodiments, as shown in FIG8 , it is a schematic diagram of the structure of the photon terahertz communication sensing system provided by the present invention. The photon terahertz communication sensing system further includes a central unit 30, the central unit 30 includes a modulated light determination module 301; the remote unit 10 further includes: a beam splitting module 107, a first optical bandpass filter 111, a first laser 108, a first polarization-maintaining fiber coupler 109 and a second coupling module 112;

The beam splitting module 107 is used to determine the first reference optical signal according to the modulated optical signal generated by the modulated optical determination module 301, where the modulated optical signal is an asymmetric optical single sideband signal containing an optical carrier;

A first optical bandpass filter 111, configured to filter the first reference optical signal to obtain a target optical carrier signal;

A first polarization-maintaining fiber coupler 109, configured to determine a second sub-optical local oscillator signal according to the optical local oscillator signal generated by the first laser 108;

The second coupling module 112 is configured to determine a second coupling signal according to the target optical carrier signal and the second sub-optical local oscillator signal.

In the embodiment of the present invention, after generating the modulated optical signal, the modulated optical determination module 301 transmits the modulated optical signal to the beam splitting module 107 through the single-mode optical fiber to achieve the distance of the modulated optical signal. After receiving the modulated optical signal, the beam splitting module 107 performs beam splitting correlation processing on the modulated optical signal to obtain a first reference optical signal, and transmits the first reference optical signal to the first optical bandpass filter 111; the first optical bandpass filter 111 effectively filters out unnecessary frequency components from the first reference optical signal, and filters out the required optical carrier signal, that is, the target optical carrier signal, and transmits the target optical carrier signal to the second coupling module 112; at the same time, the first laser 108 generates an optical local oscillator signal, and transmits the optical local oscillator signal to the first polarization-maintaining fiber coupler 109; the optical local oscillator signal is divided into two signals by the first polarization-maintaining fiber coupler 109, one of which is the second sub-optical local oscillator signal, and the second sub-optical local oscillator signal is transmitted to the second coupling module 112. Based on this, the second coupling module 112 performs coupling correlation processing on the second sub-optical local oscillator signal and the target optical carrier signal to obtain a second coupled signal, which carries the processed second sub-optical local oscillator signal and the first reference optical signal, providing effective data information for generating a reference terahertz local oscillator signal.

In some embodiments, as shown in FIG9 , it is a schematic diagram of the structure of the second coupling module provided by the present invention. The second coupling module 112 includes a third polarization-maintaining fiber coupler 1121, a second erbium-doped fiber amplifier 1122, and a second variable optical attenuator 1123;

The third polarization-maintaining fiber coupler 1121 is used to determine the third signal according to the target optical carrier signal and the second sub-optical local oscillator signal;

The second erbium-doped fiber amplifier 1122 is used to amplify the optical power of the third signal to determine the fourth signal;

The second variable optical attenuator 1123 is used to optimize the optical power of the fourth signal to obtain a second coupled signal.

In the embodiment of the present invention, after the third polarization-maintaining fiber coupler 1121 receives the second sub-optical local oscillator signal transmitted by the first polarization-maintaining fiber coupler 109 and receives the target optical carrier signal transmitted by the first optical bandpass filter 111, the third polarization-maintaining fiber coupler 1121 couples the second sub-optical local oscillator signal and the target optical carrier signal to obtain a third signal, and transmits the third signal to the second erbium-doped fiber amplifier 1122 for optical power amplification to obtain a fourth signal, and the fourth signal has good signal quality and high fidelity; the second erbium-doped fiber amplifier 1122 transmits the fourth signal to the second variable optical attenuator 1123 for optical power optimization to further improve the signal quality and fidelity of the fourth signal, and obtains a second coupled signal, which carries the processed second sub-optical local oscillator signal and the first reference optical signal, and provides effective data information for generating a reference terahertz local oscillator signal.

In some embodiments, as shown in FIG10 , it is a schematic diagram of the structure of the modulated light determination module provided by the present invention. The modulated light determination module 301 includes: a second laser 3011, a transmitting end signal processing unit 3012, a digital-to-analog converter 3013, a first electro-optical modulator 3014 and a first circulator 3015;

The digital-to-analog converter 3013 is used to determine the second synaesthesia signal according to the first synaesthesia signal generated by the transmitting end signal processing unit 3012;

A first electro-optic modulator 3014, configured to determine a modulated optical signal according to the second synaesthesia signal and the optical carrier signal generated by the second laser 3011;

The first circulator 3015 is used to transmit the modulated optical signal to the beam splitting module 107 .

The first synaesthesia signal is a digital signal, and the second synaesthesia signal is an analog signal.

In the embodiment of the present invention, the signal processing unit 3012 at the transmitting end generates a first interaural signal containing communication and perception data, and transmits the first interaural signal to the digital-to-analog converter 3013 for digital-to-analog conversion to obtain a second interaural signal; the digital-to-analog converter 3013 transmits the second interaural signal to the first electro-optical modulator 3014, at which time, the first electro-optical modulator 3014 is driven by the second interaural signal; at the same time, the second laser 3011 generates an optical carrier signal, and transmits the optical carrier signal to the first electro-optical modulator 3014. Based on this, the first electro-optical modulator 3014 performs electro-optical modulation on the optical carrier signal based on the second interaural signal to generate an asymmetric optical single-sideband signal containing an optical carrier, that is, a modulated optical signal; the first electro-optical modulator 3014 transmits the modulated optical signal to port 1 of the first circulator 3015, and the first circulator 3015 outputs the modulated optical signal from port 2, and transmits it to the beam splitter module 107 through a single-mode optical fiber to achieve the distance of the modulated optical signal.

In some embodiments, as shown in FIG11 , it is a schematic diagram of the structure of a beam splitting module provided by the present invention. The beam splitting module 107 includes: a second circulator 1071, a third erbium-doped fiber amplifier 1072, a polarization controller 1073 and a polarization-maintaining beam splitter 1074;

The second circulator 1071 is used to receive the modulated light signal transmitted by the modulated light determination module 301;

The third erbium-doped fiber amplifier 1072 is used to amplify the optical power of the modulated optical signal to determine the first modulated optical signal;

A polarization controller 1073, configured to perform polarization processing on the first modulated optical signal to obtain a second modulated optical signal;

The polarization-maintaining beam splitter 1074 is used to perform beam splitting processing on the second modulated optical signal to obtain a downlink optical signal.

It should be noted that the polarization-maintaining beam splitter 1074 performs beam splitting processing on the second modulated optical signal to obtain a downlink optical signal and a first reference optical signal.

In the embodiment of the present invention, the first circulator 3015 in the modulated light determination module 301 outputs a modulated light signal from port 2, and transmits it to port 1 of the second circulator 1071 in the beam splitting module 107 through a single-mode optical fiber. After the modulated light signal is received at port 1 of the second circulator 1071, the second circulator 1071 outputs the modulated light signal from port 2, and transmits the modulated light signal to the third erbium-doped fiber amplifier 1072 for optical power amplification to compensate for the loss caused by electro-optical modulation and optical fiber telescopic transmission, thereby obtaining a first modulated light signal; the third erbium-doped fiber amplifier 1072 transmits the first modulated light signal to the polarization controller 1073 for polarization processing, thereby controlling the polarization state of the first modulated light signal, thereby obtaining a second modulated light signal; the polarization controller 1073 transmits the second modulated light signal to the polarization-maintaining beam splitter 1074 for beam splitting processing, thereby obtaining a downlink light signal and a first reference light signal, wherein the downlink light signal provides effective data information for generating a terahertz synaesthesia signal, and the first reference light signal provides effective data information for generating a reference terahertz local oscillator signal.

In some embodiments, as shown in Fig. 12, it is a schematic diagram of the structure of a user unit provided by the present invention. The user unit 20 includes: a terahertz envelope detection module 202 and a communication signal processing module 203;

The terahertz envelope detection module 202 is used to determine a first intermediate frequency synaesthesia signal according to the terahertz synaesthesia signal;

The communication signal processing module 203 is used to determine the communication information according to the first intermediate frequency synaesthesia signal.

The first intermediate frequency synaesthesia signal is also called a downlink first intermediate frequency synaesthesia signal.

The communication information is downlink communication information.

In the embodiment of the present invention, after receiving the terahertz synaesthesia signal sent by the first antenna 105, the second antenna 201 transmits the terahertz synaesthesia signal to the terahertz envelope detection module 202; the terahertz envelope detection module 202 performs envelope detection correlation processing on the terahertz synaesthesia signal to obtain a first intermediate frequency synaesthesia signal, and transmits the first intermediate frequency synaesthesia signal to the communication signal processing module 203; the communication signal processing module 203 performs signal processing on the first intermediate frequency synaesthesia signal to effectively restore downlink communication information.

In some embodiments, as shown in FIG13 , which is a schematic diagram of the structure of the terahertz envelope detection module provided by the present invention, the terahertz envelope detection module 202 includes: a third terahertz low-noise power amplifier 2021 and a terahertz envelope detector 2022; as shown in FIG14 , which is a schematic diagram of the structure of the communication signal processing module provided by the present invention, the communication signal processing module 203 includes: a first intermediate frequency low-noise power amplifier 2031, an electrical bandpass filter 2032, a first analog-to-digital converter 2033 and a communication signal processing unit 2034;

A third terahertz low-noise power amplifier 2021 is used to amplify the power of the terahertz synaesthesia signal to obtain a fifth signal;

A terahertz envelope detector 2022, configured to perform envelope detection on the fifth signal to obtain a first intermediate frequency synaesthesia signal;

A first intermediate frequency low noise power amplifier 2031 is used to amplify the power of the first intermediate frequency synaesthesia signal to obtain a second intermediate frequency synaesthesia signal;

An electrical bandpass filter 2032, configured to filter the second intermediate frequency communication signal to obtain a first communication signal;

A first analog-to-digital converter 2033 is used to perform analog-to-digital conversion on the first communication signal to obtain a second communication signal;

The communication signal processing unit 2034 is used to process the second communication signal to obtain communication information.

In the embodiment of the present invention, during the process of the user unit 20 determining the communication information, after receiving the terahertz synaesthesia signal sent by the first antenna 105, the second antenna 201 transmits the terahertz synaesthesia signal to the third terahertz low-noise power amplifier 2021 for power amplification to obtain a fifth signal; the third terahertz low-noise power amplifier 2021 transmits the fifth signal to the terahertz envelope detector 2022 for envelope detection. During the envelope detection process, the terahertz envelope detector 2022 can effectively eliminate the frequency deviation and phase noise caused by the heterodyne beat frequency to obtain the first intermediate frequency synaesthesia signal. The terahertz envelope detector 2022 The first intermediate frequency synaesthesia signal is transmitted to the first intermediate frequency low noise power amplifier 2031 for power amplification to obtain a second intermediate frequency synaesthesia signal; the first intermediate frequency low noise power amplifier 2031 transmits the second intermediate frequency synaesthesia signal to the electric band pass filter 2032 for filtering, filtering out the first communication signal containing downlink communication information; the electric band pass filter 2032 transmits the first communication signal to the first analog-to-digital converter 2033 for analog-to-digital conversion to obtain the second communication signal; the first analog-to-digital converter 2033 transmits the second communication signal to the communication signal processing unit 2034 for signal processing, which can effectively restore the downlink communication information. In the whole process, low frequency deviation and low phase noise reception of the communication signal are realized, thereby reducing the complexity and power consumption of the communication-related algorithm.

In some embodiments, as shown in FIG15 , which is a schematic diagram of the structure of the remote unit provided by the present invention, the remote unit 10 further includes: an electro-optical modulation module 113; as shown in FIG16 , which is a schematic diagram of the structure of the central unit provided by the present invention, the central unit 30 further includes: a sensing signal processing module 302;

The electro-optical modulation module 113 is used to determine the target echo electro-optical modulation signal according to the target radar echo signal;

The sensing signal processing module 302 is used to determine the terminal-related information of the user unit according to the target echo electro-optical modulation signal.

Optionally, the terminal related information may include information such as the location and speed of the user terminal.

In an embodiment of the present invention, in the process of the central unit 30 determining terminal-related information, after the terahertz mixer 1033 transmits the target radar echo signal to the electro-optical modulation module 113, the electro-optical modulation module 113 processes the target radar echo signal to obtain a target echo electro-optical modulation signal, and transmits the target echo electro-optical modulation signal to the perception signal processing module 302 in sequence through port 3 of the second circulator 1071, port 1 of the second circulator 1071, the single-mode optical fiber, port 2 of the first circulator 3015, and port 3 of the first circulator 3015; the perception signal processing module 302 performs signal processing on the target echo electro-optical modulation signal, and can effectively obtain terminal-related information such as the position and speed of the user terminal.

In some embodiments, as shown in FIG17 , it is a schematic diagram of the structure of the electro-optic modulation module provided by the present invention. The electro-optic modulation module 113 includes: a second intermediate frequency low noise power amplifier 1131, a second electro-optic modulator 1132, a fourth erbium-doped fiber amplifier 1133 and a second optical bandpass filter 1134;

The beam splitting module 107 is further used to determine a second reference optical signal according to the modulated optical signal;

The second intermediate frequency low noise power amplifier 1131 is used to amplify the power of the target radar echo signal to obtain a third radar echo signal;

The second electro-optical modulator 1132 is used to determine the first echo electro-optical modulation signal according to the third radar echo signal and the second reference optical signal;

The fourth erbium-doped fiber amplifier 1133 is used to amplify the optical power of the first echo electro-optical modulation signal to obtain a second echo electro-optical modulation signal;

The second optical bandpass filter 1134 is used to filter the second echo electro-optical modulation signal to obtain a target echo electro-optical modulation signal.

It should be noted that the polarization-maintaining beam splitter 1074 in the beam splitting module 107 performs beam splitting processing on the second modulated optical signal, and in addition to obtaining the downlink optical signal and the first reference optical signal, can also obtain the second reference optical signal.

In an embodiment of the present invention, after the terahertz mixer 1033 transmits the target radar echo signal to the second intermediate frequency low noise power amplifier 1131, the second intermediate frequency low noise power amplifier 1131 performs power amplification on the target radar echo signal to obtain a third radar echo signal, and transmits the third radar echo signal to the second electro-optical modulator 1132; at the same time, the polarization-maintaining beam splitter 1074 in the beam splitting module 107 transmits the obtained second reference light signal to the second electro-optical modulator 1132. Based on this, the second electro-optical modulator 1132 electro-optically modulates the second reference optical signal based on the third radar echo signal, that is, modulates the third radar echo signal on the second reference optical signal to obtain a first echo electro-optical modulated signal; the second electro-optical modulator 1132 transmits the first echo electro-optical modulated signal to the fourth erbium-doped fiber amplifier 1133 for optical power amplification to compensate for the loss caused by the electro-optical modulation to obtain a second echo electro-optical modulated signal; the fourth erbium-doped fiber amplifier 1133 transmits the second echo electro-optical modulated signal to the second optical bandpass filter 1134 for filtering, effectively reducing the influence of noise and other interference signals, filtering out the perception sideband, that is, the target echo electro-optical modulated signal, the signal quality of the target echo electro-optical modulated signal is good, and can ensure that effective information is not lost during the optical fiber telemetry transmission process.

In some embodiments, as shown in FIG18 , it is a schematic diagram of the structure of the perception signal processing module provided by the present invention. The perception signal processing module 302 includes: a low-speed photodetector 3021, a third intermediate frequency low-noise power amplifier 3022, a second analog-to-digital converter 3023 and a perception signal processing unit 3024;

The low-speed photoelectric detector 3021 is used to perform beat frequency de-chirping on the target echo electro-optical modulation signal to obtain an electrical intermediate frequency sensing signal;

The third intermediate frequency low noise power amplifier 3022 is used to amplify the power of the electrical intermediate frequency perception signal to obtain a first electrical intermediate frequency perception signal;

The second analog-to-digital converter 3023 is used to perform analog-to-digital conversion on the first electrical intermediate frequency perception signal to obtain a second electrical intermediate frequency perception signal;

The perception signal processing unit 3024 is configured to process the second electrical intermediate frequency perception signal to obtain terminal related information.

In an embodiment of the present invention, after the target echo electro-optical modulation signal is transmitted from port 3 of the first circulator 3015 to the low-speed photodetector 3021, the low-speed photodetector 3021 performs beat frequency demodulation on the target echo electro-optical modulation signal to generate an electrical intermediate frequency perception signal related to information such as the position and speed of the user terminal; the low-speed photodetector 3021 transmits the electrical intermediate frequency perception signal to the third intermediate frequency low noise power amplifier 3022 for power amplification to obtain a first electrical intermediate frequency perception signal; the third intermediate frequency low noise power amplifier 3022 transmits the first electrical intermediate frequency perception signal to the second analog-to-digital converter 3023 for analog-to-digital conversion to obtain a second electrical intermediate frequency perception signal; the second analog-to-digital converter 3023 transmits the second electrical intermediate frequency perception signal to the perception signal processing unit 3024 for signal processing, which can effectively obtain terminal-related information such as the position and speed of the user terminal.

The embodiments of the present invention are further described with reference to the following examples:

For example, as shown in FIG19 , it is a schematic diagram of the structure of the photonic terahertz communication sensing system provided by the present invention. In FIG19 , CU (Center Unit) 30 represents the central unit 30, RU (Remote Unit) 10 represents the remote unit 10, UE (User Element) 20 represents the user element 20, Sen.Receiver (Sensitivity Receiver) represents the radar receiving end, and Com.Receiver (Communication Receiver) represents the communication receiving end;

In CU30: LD (Laser Diode) 2 represents the second laser 3011; Tx.DSP (Transmit Digital Signal Processing) represents the transmitter signal processing unit 3012; DAC (Digital to Analog Convertor) represents the digital-to-analog converter 3013; Mod (Modulator).1 represents the first electro-optical modulator 3014; CIR (Circulator) 1 represents the first circulator 3015; LS-PD (Low Speed Photodetector) represents the low-speed photodetector 3021; IF-LNA (Intermediate Frequency-Low Noise power Amplifier) 3 represents the third intermediate frequency low-noise power amplifier 3022; ADC (Analog to Digital Converter) 2 represents the second analog-to-digital converter 3023; Sen.DSP (Sensitivity Digital Signal Processing) represents the sensing signal processing unit 3024;

SMF (Single-Mode optical Fiber) means single-mode optical fiber;

In RU10, CIR2 represents the second circulator 1071; EDFA (Erbium Doped Fiber Amplifier) 3 represents the third erbium-doped fiber amplifier 1072; PC (Polarization Controller) represents the polarization controller 1073; PM-OS (Polarization Maintaining-fiber Optic Splitting) represents the polarization-maintaining optical beam splitter 1074; LD1 represents the first laser 108; PM-OC (Polarization Maintaining-fiber Optic Coupler) 1 represents the first polarization-maintaining fiber coupler 109; PM-OC2 represents the second polarization-maintaining fiber coupler 1101; EDFA1 represents the first erbium-doped fiber amplifier 1102; VOA (Variable Optical Attenuator) 1 represents the first variable optical attenuator 1103; HS-PD (High Speed-Photodetectors) 1 represents the first high-speed photodetector 101; PA (Power Amplifier) represents the terahertz power amplifier 104; Ant (Antenna) 1 represents the first antenna 105; OBPF (Optical Bandpass Filter)1 represents the first optical bandpass filter 111; PM-OC3 represents the third polarization-maintaining fiber coupler 1121; EDFA2 represents the second erbium-doped fiber amplifier 1122; VOA2 represents the second variable optical attenuator 1123; HS-PD2 represents the second high-speed photodetector 102; LNA (LowNoise power Amplifier)1 represents the first terahertz low-noise power amplifier 1031; Mixer represents the terahertz mixer 1033; LNA2 represents the second terahertz low-noise power amplifier 1032; Ant3 represents the third antenna 106; Mod.2 represents the second electro-optical modulator 1132; IF-LNA2 represents the second intermediate frequency low-noise power amplifier 1131; OBPF2 represents the second optical bandpass filter 1134; EDFA4 represents the fourth erbium-doped fiber amplifier 1133;

In UE20: Ant2 represents the second antenna 201; LNA3 represents the third terahertz low noise power amplifier 2021; ED (Envelope Detector) represents the terahertz envelope detector 2022; IF-LNA1 represents the first intermediate frequency low noise power amplifier 2031; EBPF (Electric Bandpass Filter) represents the electric bandpass filter 2032; ADC1 represents the first analog-to-digital converter 2033; Com.DSP (Communication Digital Signal Processing) represents the communication signal processing unit 2034.

In conjunction with FIG19, as shown in FIG20, it is a schematic diagram of the optical spectrum and electric spectrum of different nodes of the photonic terahertz communication perception system provided by the present invention. It should be noted that the frequency interval between the communication signal sideband and the optical carrier signal is _f1 , the frequency interval between the perception signal sideband and the optical carrier signal is _f2 , the frequency interval between the optical local oscillator signal and the optical carrier signal is _fTHZ , and the center carrier frequency of the terahertz synaesthesia signal is _fTHZ . FIG20(a) is a schematic diagram of the modulated optical signal at point (a) in FIG19. FIG20(b) is a schematic diagram of the first signal at point (b) in FIG19. FIG20(c) is a schematic diagram of the third signal at point (c) in FIG19. FIG20(d) is a schematic diagram of the terahertz synaesthesia signal at point (d) in FIG19. FIG20(e) is a schematic diagram of the first echo electro-optical modulation signal at point (e) in FIG19. FIG20(f) is a schematic diagram of the target echo electro-optical modulation signal at point (f) in FIG19. FIG20(g) is a schematic diagram of the first intermediate frequency synaesthesia signal at point (g) in FIG19. Since asymmetric single sideband modulation is used in the central unit 30, the frequency of the signal-signal beat frequency interference (SSBI) generated by the interaction between the communication signal and the perception signal is much higher than the frequency of the communication signal; only the SSBI generated by the self-beat frequency of the communication signal is distributed near the direct current (DC), which can reduce the frequency protection interval set to eliminate the SSBI. In order to ensure that the communication signal and the perception signal do not overlap in frequency, it is necessary to satisfy _f1 + _BWCom /2＜ _f2 - _BWSen /2, where _BWCom and _BWSen represent the communication signal bandwidth and the perception signal bandwidth, respectively.

The photonic terahertz communication sensing method provided in an embodiment of the present application is described below. The photonic terahertz communication sensing method described below and the photonic terahertz communication sensing system described above can refer to each other.

As shown in FIG. 21 , it is a flow chart of the photon terahertz communication sensing method provided by the present invention, which is applied to the photon terahertz communication sensing system described above. The photon terahertz communication sensing system includes a remote unit and a user unit. The remote unit includes: a first high-speed photodetector, a second high-speed photodetector and a terahertz mixing module. The method includes:

2101. Perform heterodyne beat frequency analysis on the first coupled signal using a first high-speed photodetector to obtain a terahertz synaesthesia signal;

2102. Perform heterodyne beat frequency on the second coupled signal using a second high-speed photodetector to obtain a reference terahertz local oscillator signal, wherein the terahertz synaesthesia signal and the reference terahertz local oscillator signal have the same frequency offset, the first coupled signal and the second coupled signal are both obtained based on the optical carrier signal and the optical local oscillator signal, and the first coupled signal and the second coupled signal are different;

2103. Determine a first radar echo signal using a user unit according to the terahertz synaesthesia signal;

2104. Determine the target radar echo signal according to the reference terahertz local oscillator signal and the first radar echo signal using a terahertz mixing module.

Optionally, the photonic terahertz communication perception system also includes a central unit, which includes a modulated light determination module; the remote unit also includes: a beam splitting module, a first laser, a first polarization-maintaining fiber coupler and a first coupling module; including: using the beam splitting module to determine a downlink optical signal according to a modulated light signal generated by the modulated light determination module, wherein the modulated light signal is an asymmetric optical single-sideband signal containing an optical carrier; using the first polarization-maintaining fiber coupler to determine a first sub-optical local oscillator signal according to the optical local oscillator signal generated by the first laser; and using the first coupling module to determine the first coupling signal according to the downlink optical signal and the first sub-optical local oscillator signal.

Optionally, the user unit includes: a terahertz envelope detection module and a communication signal processing module; including: using the terahertz envelope detection module to determine a first intermediate frequency synaesthesia signal according to the terahertz synaesthesia signal; using the communication signal processing module to determine communication information according to the first intermediate frequency synaesthesia signal.

Optionally, the first coupling module includes a second polarization-maintaining fiber coupler, a first erbium-doped fiber amplifier and a first variable optical attenuator; including: using the second polarization-maintaining fiber coupler to determine the first signal according to the downlink optical signal and the first sub-optical local oscillator signal; using the first erbium-doped fiber amplifier to amplify the optical power of the first signal to determine the second signal; using the first variable optical attenuator to optimize the optical power of the second signal to obtain the first coupled signal.

Optionally, the photonic terahertz communication perception system also includes a central unit, which includes a modulated light determination module; the remote unit also includes: a beam splitting module, a first optical bandpass filter, a first laser, a first polarization-maintaining fiber coupler and a second coupling module; including: using the beam splitting module to determine a first reference optical signal according to the modulated light signal generated by the modulated light determination module, wherein the modulated light signal is an asymmetric optical single-sideband signal containing an optical carrier; using the first optical bandpass filter to filter the first reference optical signal to obtain a target optical carrier signal; using the first polarization-maintaining fiber coupler to determine a second sub-optical local oscillator signal according to the optical local oscillator signal generated by the first laser; and using the second coupling module to determine the second coupling signal according to the target optical carrier signal and the second sub-optical local oscillator signal.

Optionally, the second coupling module includes a third polarization-maintaining fiber coupler, a second erbium-doped fiber amplifier and a second variable optical attenuator; including: using the third polarization-maintaining fiber coupler to determine a third signal according to the target optical carrier signal and the second sub-optical local oscillator signal; using the second erbium-doped fiber amplifier to amplify the optical power of the third signal to determine a fourth signal; and using the second variable optical attenuator to optimize the optical power of the fourth signal to obtain the second coupled signal.

Optionally, the modulated light determination module includes: a second laser, a transmitting end signal processing unit, a digital-to-analog converter, a first electro-optical modulator and a first circulator; including: using the digital-to-analog converter to determine the second synaesthesia signal according to the first synaesthesia signal generated by the transmitting end signal processing unit; using the first electro-optical modulator to determine the modulated light signal according to the second synaesthesia signal and the optical carrier signal generated by the second laser; and using the first circulator to transmit the modulated light signal to the beam splitting module.

Optionally, the beam splitting module includes: a second circulator, a third erbium-doped fiber amplifier, a polarization controller and a polarization-maintaining beam splitter; including: using the second circulator to receive the modulated light signal transmitted by the modulated light determination module; using the third erbium-doped fiber amplifier to amplify the optical power of the modulated light signal to determine the first modulated light signal; using the polarization controller to perform polarization processing on the first modulated light signal to obtain a second modulated light signal; using the polarization-maintaining beam splitter to perform beam splitting processing on the second modulated light signal to obtain the downlink light signal.

Optionally, the terahertz mixing module includes: a first terahertz low-noise power amplifier, a second terahertz low-noise power amplifier and a terahertz mixer; including: using the first terahertz low-noise power amplifier to power amplify the reference terahertz local oscillator signal to obtain a target reference terahertz local oscillator signal; using the second terahertz low-noise power amplifier to power amplify the first radar echo signal to obtain a second radar echo signal; using the terahertz mixer to mix the target reference terahertz local oscillator signal and the second radar echo signal to obtain the target radar echo signal.

Optionally, the terahertz envelope detection module includes: a third terahertz low-noise power amplifier and a terahertz envelope detector; the communication signal processing module includes: a first intermediate frequency low-noise power amplifier, an electrical bandpass filter, a first analog-to-digital converter and a communication signal processing unit; including: using the third terahertz low-noise power amplifier to power amplify the terahertz synaesthesia signal to obtain a fifth signal; using the terahertz envelope detector to envelope detect the fifth signal to obtain the first intermediate frequency synaesthesia signal; using the first intermediate frequency low-noise power amplifier to power amplify the first intermediate frequency synaesthesia signal to obtain a second intermediate frequency synaesthesia signal; using the electrical bandpass filter to filter the second intermediate frequency synaesthesia signal to obtain a first communication signal; using the first analog-to-digital converter to perform analog-to-digital conversion on the first communication signal to obtain a second communication signal; using the communication signal processing unit to process the second communication signal to obtain the communication information.

Optionally, the remote unit also includes: an electro-optical modulation module; the central unit also includes: a perception signal processing module; including: using the electro-optical modulation module to determine the target echo electro-optical modulation signal according to the target radar echo signal; using the perception signal processing module to determine the terminal-related information of the user unit according to the target echo electro-optical modulation signal.

Optionally, the electro-optical modulation module includes: a second intermediate frequency low noise power amplifier, a second electro-optical modulator, a fourth erbium-doped fiber amplifier and a second optical bandpass filter; including: using the beam splitting module to determine a second reference optical signal according to the modulated optical signal; using the second intermediate frequency low noise power amplifier to power amplify the target radar echo signal to obtain a third radar echo signal; using the second electro-optical modulator to determine a first echo electro-optical modulation signal according to the third radar echo signal and the second reference optical signal; using the fourth erbium-doped fiber amplifier to perform optical power amplification on the first echo electro-optical modulation signal to obtain a second echo electro-optical modulation signal; using the second optical bandpass filter to filter the second echo electro-optical modulation signal to obtain the target echo electro-optical modulation signal.

Optionally, the perception signal processing module includes: a low-speed photodetector, a third intermediate frequency low-noise power amplifier, a second analog-to-digital converter and a perception signal processing unit; including: using the low-speed photodetector to perform beat frequency demodulation on the target echo electro-optical modulation signal to obtain an electrical intermediate frequency perception signal; using the third intermediate frequency low-noise power amplifier to power amplify the electrical intermediate frequency perception signal to obtain a first electrical intermediate frequency perception signal; using the second analog-to-digital converter to perform analog-to-digital conversion on the first electrical intermediate frequency perception signal to obtain a second electrical intermediate frequency perception signal; using the perception signal processing unit to process the second electrical intermediate frequency perception signal to obtain terminal related information.

The system embodiment described above is merely illustrative, wherein the units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, and may be located in one place, or may be distributed on multiple network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the solution of this embodiment. Those of ordinary skill in the art can understand and implement it without creative effort.

Through the description of the above implementation methods, those skilled in the art can clearly understand that each implementation method can be implemented by means of software plus a necessary general hardware platform, and of course, it can also be implemented by hardware. Based on this understanding, the above technical solution is essentially or the part that contributes to the prior art can be embodied in the form of a software product, and the computer software product can be stored in a computer-readable storage medium, such as ROM/RAM, a disk, an optical disk, etc., including a number of instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to execute the methods described in each embodiment or some parts of the embodiments.

Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims (14)

1. A photonic terahertz communication sensing system, characterized in that it comprises: a remote unit and a user unit, the remote unit comprises: a first high-speed photodetector, a second high-speed photodetector and a terahertz mixing module, the system comprises: The first high-speed photodetector is used to perform heterodyne beat frequency on the first coupled signal to obtain a terahertz synaesthesia signal; The second high-speed photodetector is used to perform heterodyne beat frequency on the second coupled signal to obtain a reference terahertz local oscillator signal, the terahertz synaesthesia signal and the reference terahertz local oscillator signal have the same frequency offset, the first coupled signal and the second coupled signal are both obtained based on the optical carrier signal and the optical local oscillator signal, and the first coupled signal and the second coupled signal are different; The user unit is used to determine a first radar echo signal according to the terahertz synaesthesia signal; The terahertz mixing module is used to determine the target radar echo signal according to the reference terahertz local oscillator signal and the first radar echo signal. 2. The system according to claim 1, further comprising a central unit, wherein the central unit comprises a modulated light determination module; the remote unit further comprises: a beam splitting module, a first laser, a first polarization-maintaining fiber coupler and a first coupling module; The beam splitting module is used to determine the downlink optical signal according to the modulated optical signal generated by the modulated optical determination module, wherein the modulated optical signal is an asymmetric optical single sideband signal containing an optical carrier; The first polarization-maintaining fiber coupler is used to determine a first sub-optical local oscillator signal according to the optical local oscillator signal generated by the first laser; The first coupling module is used to determine the first coupling signal according to the downlink optical signal and the first sub-optical local oscillator signal. 3. The system according to claim 1, characterized in that the user unit comprises: a terahertz envelope detection module and a communication signal processing module; The terahertz envelope detection module is used to determine a first intermediate frequency synaesthesia signal according to the terahertz synaesthesia signal; The communication signal processing module is used to determine communication information according to the first intermediate frequency synaesthesia signal. 4. The system according to claim 2, wherein the first coupling module comprises a second polarization-maintaining fiber coupler, a first erbium-doped fiber amplifier and a first variable optical attenuator; The second polarization-maintaining optical fiber coupler is used to determine the first signal according to the downlink optical signal and the first sub-optical local oscillator signal; The first erbium-doped fiber amplifier is used to amplify the optical power of the first signal to determine a second signal; The first variable optical attenuator is used to optimize the optical power of the second signal to obtain the first coupled signal. 5. The system according to claim 1, further comprising a central unit, wherein the central unit comprises a modulated light determination module; the remote unit further comprises: a beam splitting module, a first optical bandpass filter, a first laser, a first polarization-maintaining fiber coupler, and a second coupling module; The beam splitting module is used to determine a first reference optical signal according to the modulated optical signal generated by the modulated optical determination module, wherein the modulated optical signal is an asymmetric optical single sideband signal containing an optical carrier; The first optical bandpass filter is used to filter the first reference optical signal to obtain a target optical carrier signal; The first polarization-maintaining fiber coupler is used to determine a second sub-optical local oscillator signal according to the optical local oscillator signal generated by the first laser; The second coupling module is used to determine the second coupling signal according to the target optical carrier signal and the second sub-optical local oscillator signal. 6. The system according to claim 5, characterized in that the second coupling module comprises a third polarization-maintaining fiber coupler, a second erbium-doped fiber amplifier and a second variable optical attenuator; The third polarization-maintaining fiber coupler is used to determine a third signal according to the target optical carrier signal and the second sub-optical local oscillator signal; The second erbium-doped fiber amplifier is used to amplify the optical power of the third signal to determine a fourth signal; The second variable optical attenuator is used to optimize the optical power of the fourth signal to obtain the second coupled signal. 7. The system according to claim 2 or 5, characterized in that the modulated light determination module comprises: a second laser, a transmitting end signal processing unit, a digital-to-analog converter, a first electro-optical modulator and a first circulator; The digital-to-analog converter is used to determine a second synaesthesia signal according to the first synaesthesia signal generated by the transmitting-end signal processing unit; The first electro-optic modulator is used to determine the modulated optical signal according to the second synaesthesia signal and the optical carrier signal generated by the second laser; The first circulator is used to transmit the modulated optical signal to the beam splitting module. 8. The system according to claim 2 or 4, characterized in that the beam splitting module comprises: a second circulator, a third erbium-doped fiber amplifier, a polarization controller and a polarization-maintaining beam splitter; The second circulator is used to receive the modulated light signal transmitted by the modulated light determination module; The third erbium-doped fiber amplifier is used to amplify the optical power of the modulated optical signal to determine the first modulated optical signal; The polarization controller is used to perform polarization processing on the first modulated optical signal to obtain a second modulated optical signal; The polarization-maintaining beam splitter is used to perform beam splitting processing on the second modulated optical signal to obtain the downlink optical signal. 9. The system according to claim 1, characterized in that the terahertz mixing module comprises: a first terahertz low noise power amplifier, a second terahertz low noise power amplifier and a terahertz mixer; The first terahertz low-noise power amplifier is used to amplify the power of the reference terahertz local oscillator signal to obtain a target reference terahertz local oscillator signal; The second terahertz low-noise power amplifier is used to amplify the power of the first radar echo signal to obtain a second radar echo signal; The terahertz mixer is used to mix the target reference terahertz local oscillator signal and the second radar echo signal to obtain the target radar echo signal. 10. The system according to claim 3, characterized in that the terahertz envelope detection module comprises: a third terahertz low-noise power amplifier and a terahertz envelope detector; the communication signal processing module comprises: a first intermediate frequency low-noise power amplifier, an electrical bandpass filter, a first analog-to-digital converter and a communication signal processing unit; The third terahertz low-noise power amplifier is used to amplify the power of the terahertz synaesthesia signal to obtain a fifth signal; The terahertz envelope detector is used to perform envelope detection on the fifth signal to obtain the first intermediate frequency synaesthesia signal; The first intermediate frequency low noise power amplifier is used to amplify the power of the first intermediate frequency synaesthesia signal to obtain a second intermediate frequency synaesthesia signal; The electric bandpass filter is used to filter the second intermediate frequency communication signal to obtain a first communication signal; The first analog-to-digital converter is used to perform analog-to-digital conversion on the first communication signal to obtain a second communication signal; The communication signal processing unit is used to process the second communication signal to obtain the communication information. 11. The system according to claim 2 or 5, characterized in that the remote unit further comprises: an electro-optical modulation module; the central unit further comprises: a sensing signal processing module; The electro-optical modulation module is used to determine the target echo electro-optical modulation signal according to the target radar echo signal; The perception signal processing module is used to determine the terminal-related information of the user unit according to the target echo electro-optical modulation signal. 12. The system according to claim 11, characterized in that the electro-optical modulation module comprises: a second intermediate frequency low noise power amplifier, a second electro-optical modulator, a fourth erbium-doped fiber amplifier and a second optical bandpass filter; The beam splitting module is further used to determine a second reference optical signal according to the modulated optical signal; The second intermediate frequency low noise power amplifier is used to amplify the power of the target radar echo signal to obtain a third radar echo signal; The second electro-optical modulator is used to determine a first echo electro-optical modulation signal according to the third radar echo signal and the second reference optical signal; The fourth erbium-doped fiber amplifier is used to amplify the optical power of the first echo electro-optical modulation signal to obtain a second echo electro-optical modulation signal; The second optical bandpass filter is used to filter the second echo electro-optical modulation signal to obtain the target echo electro-optical modulation signal. 13. The system according to claim 11, characterized in that the perception signal processing module comprises: a low-speed photodetector, a third intermediate frequency low-noise power amplifier, a second analog-to-digital converter and a perception signal processing unit; The low-speed photoelectric detector is used to perform beat frequency de-chirping on the target echo electro-optical modulation signal to obtain an electrical intermediate frequency sensing signal; The third intermediate frequency low noise power amplifier is used to amplify the power of the electrical intermediate frequency perception signal to obtain a first electrical intermediate frequency perception signal; The second analog-to-digital converter is used to perform analog-to-digital conversion on the first electrical intermediate frequency perception signal to obtain a second electrical intermediate frequency perception signal; The perception signal processing unit is used to process the second electrical intermediate frequency perception signal to obtain the terminal related information. 14. A photonic terahertz communication sensing method, characterized in that it is applied to the photonic terahertz communication sensing system according to any one of claims 1 to 13, the photonic terahertz communication sensing system comprising a remote unit and a user unit, the remote unit comprising: a first high-speed photodetector, a second high-speed photodetector and a terahertz mixing module, the method comprising: Using the first high-speed photodetector to perform heterodyne beat frequency on the first coupled signal to obtain a terahertz synaesthesia signal; The second high-speed photodetector is used to perform heterodyne beat frequency on the second coupled signal to obtain a reference terahertz local oscillator signal, wherein the terahertz synaesthesia signal and the reference terahertz local oscillator signal have the same frequency offset, the first coupled signal and the second coupled signal are both obtained based on an optical carrier signal and an optical local oscillator signal, and the first coupled signal and the second coupled signal are different; Determining a first radar echo signal using the user unit according to the terahertz synaesthesia signal; The terahertz mixing module is used to determine the target radar echo signal according to the reference terahertz local oscillator signal and the first radar echo signal.