Photon-assisted annular distributed radar detection system and method

Abstract

The present invention provides a photon-assisted annular distributed radar detection system and method. The system includes: a central station, multiple transmitting stations and multiple receiving stations, wherein the central station, multiple transmitting stations and multiple receiving stations are sequentially connected by optical fibers to form an annular network; two multi-carrier optical radar signals are generated in the central station, and the first multi-carrier optical radar signal is sequentially transmitted along the first direction of the annular network; the second multi-carrier optical radar signal is sequentially transmitted along the second direction of the annular network, and a transmitting signal is obtained and transmitted based on the first multi-carrier optical radar signal in multiple transmitting stations; an echo signal consistent with the carrier frequency of the transmitting signal is received and sorted in multiple receiving stations, and the echo signal and the second multi-carrier optical radar signal are used together to generate an optical echo signal, and the optical echo signal is transmitted back to the central station along the second direction of the annular network.

Description

Technical Field

[0001] The present invention relates to the field of signal transmission, and in particular to a photon-assisted annular distributed radar detection system and method. Background Art

[0002] As military targets develop towards miniaturization, high mobility, intelligence and high concealment, the electromagnetic environment is becoming increasingly complex. The realization of accurate target detection and positioning has put forward higher requirements on the working bandwidth, distribution capability and flexible concealment of distributed radar.

[0003] Traditional electronic technology faces a "bandwidth bottleneck" and is unable to meet application requirements in terms of broadband signal generation, processing and long-distance transmission. In recent years, microwave photonic technology has become a "key technology to illuminate the future of radar" with its characteristics of large bandwidth, low loss, reusability and resistance to electromagnetic interference.

[0004] However, the photon-assisted distributed radar system in the prior art is generally distributed in a star structure, that is, the central station and each transceiver antenna unit are connected by an independent optical fiber link, and the signal distribution and return are performed in parallel. Although the links do not affect each other, each additional antenna unit requires the laying of optical fiber links from the central station, which limits the scalability and distribution capabilities of the system to a certain extent. In addition, each link is only used to send and receive one signal, resulting in a serious waste of optical fiber resources. Summary of the invention

[0005] The present invention provides a photon-assisted annular distributed radar detection system and method, aiming to overcome the problem of waste of transmission link resources and insufficient system scalability and distribution capability in the star-structured distributed radar detection system in the prior art, thereby improving the scalability of the radar network and the utilization rate of the optical fiber link, and reducing the complexity of the multi-path echo receiving link.

[0006] Specifically, the embodiment of the present invention provides the following technical solutions:

[0007] In a first aspect, an embodiment of the present invention provides a photon-assisted annular distributed radar detection system, comprising: a central station, a plurality of transmitting stations, and a plurality of receiving stations, wherein the central station, the plurality of transmitting stations, and the plurality of receiving stations are sequentially connected by optical fibers to form an annular network;

[0008] The central station is used to generate a multi-carrier optical radar signal, divide the multi-carrier optical radar signal into a first multi-carrier optical radar signal and a second multi-carrier optical radar signal, and transmit the first multi-carrier optical radar signal in sequence along the first direction of the ring network to transmitting station 1, transmitting station 2, ..., transmitting station N, respectively, introducing a first transmission delay τ t1 , τ t2 , ..., τ tNThe second multi-carrier optical radar signal is transmitted to receiving station N, ..., receiving station 2, and receiving station 1 in sequence along the second direction of the ring network, respectively introducing a second transmission delay τ rN , ..., τ r2 , τ r1 , the delay of each fiber segment in the ring network satisfies τ ri -τ ti ≠τ rj -τ tj (1≤i, j≤N and i≠j), and τ ri -τ ti Much greater than the sum of the transmission delays from the target to the antennas of the multiple transmitting stations and the multiple receiving stations; wherein N is an arbitrary positive integer;

[0009] The multiple transmitting stations are used to obtain a transmission signal based on the first multi-carrier optical radar signal, and transmit the transmission signal;

[0010] The multiple receiving stations are used to receive echo signals from the detected targets, select echo signals that are consistent with the carrier frequency of the transmitted signal, generate optical echo signals together with the second multi-carrier optical radar signal, and transmit the optical echo signals back to the central station along the second direction of the ring network.

[0011] Furthermore, the photon-assisted annular distributed radar detection system also includes:

[0012] The central station comprises:

[0013] The signal generating unit is used to generate the multi-carrier optical radar signal;

[0014] The first optical fiber circulator is used for coupling the multi-carrier optical radar signal into an optical coupler, and coupling the optical echo signal from the optical coupler into a signal processing unit;

[0015] The optical coupler is used to divide the multi-carrier optical radar signal from the first optical fiber circulator into the first multi-carrier optical radar signal and the second multi-carrier optical radar signal, and couple N optical echo signals from the second direction of the ring network into the first optical fiber circulator;

[0016] The signal processing unit is used to obtain a beam-combined de-skewed signal from N optical carrier echo signals, and to perform digital processing on the beam-combined de-skewed signal.

[0017] Furthermore, the photon-assisted annular distributed radar detection system also includes:

[0018] The plurality of transmitting stations include: a first wavelength division multiplexer, a second wavelength division multiplexer and a second optical fiber circulator, wherein the second optical fiber circulator is arranged between the first wavelength division multiplexer and the second wavelength division multiplexer;

[0019] The first wavelength division multiplexer is used to split the multi-carrier optical radar signal from the first direction of the ring network according to different carrier wavelengths, and the carrier wavelength is λ i+1 , ..., λ N The optical radar signal is coupled into the second wavelength division multiplexer, and the carrier wavelength corresponding to the transmitting station i is λ i The optical radar signal from the second wavelength division multiplexer and the carrier wavelength corresponding to the transmitting station i from the second optical fiber circulator are coupled into the second optical fiber circulator, and the ... are coupled into the second optical fiber circulator, and the carrier wavelength corresponding to the transmitting station i is coupled into the second optical fiber circulator, and the carrier wavelength corresponding to the transmitting station i is coupled into the second optical fiber circulator i The optically-carrying echo signals are combined into a beam and coupled into the ring network for transmission along a second direction;

[0020] The second wavelength division multiplexer is used to split the multi-carrier optical radar signal and the combined optical echo signal from the second direction of the ring network according to different carrier wavelengths, and the carrier wavelength corresponding to the transmitting station i is λ i The optical radar signal is coupled into the second optical fiber circulator; at the same time, the carrier wavelength λ from the first wavelength division multiplexer is coupled into the second optical fiber circulator; i+1 , ..., λ N The optical radar signals are beam-combined and coupled into the ring network to be transmitted along the first direction.

[0021] Furthermore, the photon-assisted annular distributed radar detection system also includes:

[0022] The plurality of transmitting stations also include:

[0023] The second photoelectric detector is used to detect the carrier wavelength λ corresponding to the transmitting station i. i The optical radar signal is photoelectrically converted, the comb tooth interval and the carrier frequency and bandwidth of the linear frequency modulation signal are set, and pre-transmitted signals of no less than N different frequency bands are obtained from the beat frequencies of different modulation sidebands of the optical frequency comb;

[0024] A first electrical filter, used for selecting a transmission signal from the pre-transmission signal and outputting it to the first antenna;

[0025] The first antenna is used to transmit the transmission signal to the detection target.

[0026] Furthermore, the photon-assisted annular distributed radar detection system also includes:

[0027] The plurality of receiving stations include:

[0028] The third wavelength division multiplexer is used to split the multi-carrier optical radar signal and the combined optical echo signal from the second direction of the ring network according to different carrier wavelengths, and at the same time split the carrier wavelength from the fourth wavelength division multiplexer into two different wavelengths. i+1 , ..., λ N The optical radar signal is combined into a beam and coupled into the ring network for transmission along a first direction;

[0029] The fourth wavelength division multiplexer is used to convert the carrier wavelength from the first direction of the ring network into i+1 , ..., λ N The optical radar signal is split into two beams, and the optical echo signal i corresponding to the receiving station i from the optical filter and the carrier wavelengths λ1, ..., λ from the third wavelength division multiplexer are split. i-1 The optical radar signal and the carrier wavelength are i+1 , ..., λ N The optically-carrying echo signals are combined into a beam and coupled into the ring network to be transmitted along the second direction.

[0030] Furthermore, the photon-assisted annular distributed radar detection system also includes:

[0031] The plurality of receiving stations also include:

[0032] a second antenna, for receiving an echo signal from a target;

[0033] a second electric filter, used for sorting the echo signal;

[0034] A modulator is used to modulate the echo signal to a carrier wave with a wavelength λ corresponding to the receiving station i. i on the optical radar signal to obtain an optical echo modulation signal;

[0035] The optical filter is used to select a desired modulation sideband from the light-carrying echo modulation signal to obtain the light-carrying echo signal i corresponding to the receiving station i.

[0036] Furthermore, the photon-assisted annular distributed radar detection system also includes:

[0037] The signal generating unit comprises:

[0038] The laser array is used to output N wavelengths of λ1, λ2, ..., λ N The combined optical carrier;

[0039] An optical comb generator, used to generate N optical frequency combs using the combined optical carrier, the teeth of each optical frequency comb having a consistent interval, and the wavelength ranges covered by each optical frequency comb do not overlap;

[0040] A signal source, used for generating a linear frequency modulation signal;

[0041] A modulator is used to modulate the linear frequency modulation signal onto each comb tooth of the N optical frequency combs to generate the multi-carrier optical radar signal.

[0042] Furthermore, the photon-assisted annular distributed radar detection system also includes:

[0043] The signal processing unit comprises:

[0044] a first photoelectric detector, configured to perform photoelectric conversion on the N optical echo signals to implement parallel de-skewing of the N optical echo signals and obtain the combined de-skewing signal corresponding to the multi-path echo signals;

[0045] an analog-to-digital converter, used for performing analog-to-digital conversion on the beam-combining de-skew signal;

[0046] A digital processor is used to perform digital domain processing on the beam-combined de-skewed signal after the analog-to-digital conversion.

[0047] In a second aspect, an embodiment of the present invention further provides a photon-assisted annular distributed radar detection method, comprising:

[0048] Target detection is performed using the photon-assisted annular distributed radar detection system described in any one of the first aspects above.

[0049] Further, the central station, the plurality of transmitting stations and the plurality of receiving stations are sequentially connected by optical fibers to form a ring network;

[0050] A multi-carrier optical radar signal is generated in the central station, and the multi-carrier optical radar signal is divided into a first multi-carrier optical radar signal and a second multi-carrier optical radar signal. The first multi-carrier optical radar signal is transmitted in sequence along the first direction of the ring network to transmitting station 1, transmitting station 2, ..., transmitting station N, and a first transmission delay τ is introduced respectively. t1 , τ t2 , ..., τ tN The second multi-carrier optical radar signal is transmitted to receiving station N, ..., receiving station 2, and receiving station 1 in sequence along the second direction of the ring network, respectively introducing a second transmission delay τ rN , ..., τ r2 , τ r1 , the delay of each fiber segment in the ring network satisfies τ ri -τ ti ≠τ rj -τ tj , where 1≤i, j≤N and i≠j, and τ ri -τ tiMuch greater than the sum of the transmission delays from the target to the antennas of the multiple transmitting stations and the multiple receiving stations; wherein N is an arbitrary positive integer;

[0051] In the multiple transmitting stations, a transmission signal is obtained based on the first multi-carrier optical radar signal, and the transmission signal is transmitted;

[0052] The echo signals from the detected targets are received in the multiple receiving stations, and the echo signals consistent with the carrier frequency of the transmitted signal are selected, and the echo signals are used together with the second multi-carrier optical radar signal to generate an optical echo signal, and the optical echo signal is transmitted back to the central station along the second direction of the ring network.

[0053] It can be seen from the above technical solution that a photon-assisted annular distributed radar detection system and method provided by an embodiment of the present invention utilizes optical fiber to connect a central station, multiple transmitting stations, and multiple receiving stations, and distributes and receives radar signals through optical radio frequency transmission to construct an annular distributed radar system. Multi-band signals are generated based on multi-carrier optical frequency comb external modulation detection technology to achieve frequency diversity transmission. Time diversity reception is achieved based on optical delay links. The annular distributed structure of the present invention overcomes the resource waste problem and the problem of insufficient system scalability and distribution capabilities of the star-structured distributed radar detection system in the prior art, improves the scalability of the radar network and the utilization rate of the optical fiber link, and reduces the complexity of the multi-path echo receiving link. BRIEF DESCRIPTION OF THE DRAWINGS

[0054] 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.

[0055] Figure 1 A schematic diagram of the structure of a photon-assisted annular distributed radar detection system provided by an embodiment of the present invention;

[0056] Figure 2 A schematic diagram of the structure of a transmitting station in a photon-assisted annular distributed radar detection system provided by an embodiment of the present invention;

[0057] Figure 3 A schematic diagram of the structure of a receiving station in a photon-assisted annular distributed radar detection system provided by an embodiment of the present invention; and

[0058] Figure 4 A flowchart of the steps of a photon-assisted annular distributed radar detection method provided by one embodiment of the present invention. DETAILED DESCRIPTION

[0059] 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.

[0060] The various terms or phrases used in the present invention have the general meanings known to those of ordinary skill in the art. Even so, the present invention still hopes to provide a more detailed description and explanation of these terms or phrases. If the terms and phrases involved in this article are inconsistent with the commonly known meanings, the meanings expressed in the present invention shall prevail; and if not defined in this application, they have the meanings commonly understood by those of ordinary skill in the art.

[0061] The photon-assisted distributed radar system in the prior art is generally distributed in a star structure, that is, the central station and each transceiver antenna unit are connected by an independent optical fiber link, and the signal distribution and return are performed in parallel. Although the links do not affect each other, each additional antenna unit requires the laying of optical fiber links from the central station, which limits the scalability and distribution capabilities of the system to a certain extent. In addition, each link is only used to send and receive one signal, resulting in a serious waste of optical fiber resources.

[0062] To this end, in the first aspect, an embodiment of the present invention proposes a photon-assisted ring-shaped distributed radar detection system, which aims to overcome the resource waste problem and insufficient system scalability and distribution capability of the star-structured distributed radar detection system in the prior art, improve the scalability of the radar network and the utilization rate of the optical fiber link, and reduce the complexity of the multi-path echo receiving link.

[0063] Combine the following Figure 1 The photon-assisted annular distributed radar detection system of the present invention is described.

[0064] Figure 1 A schematic diagram of the structure of a photon-assisted annular distributed radar detection system provided in one embodiment of the present invention.

[0065] In this embodiment, it should be noted that the various modules in the system of the embodiment of the present invention can be integrated into one or deployed separately. The above units can be combined into one unit or further divided into multiple sub-units.

[0066] In this embodiment, it should be noted that the photon-assisted annular distributed radar detection system may include: a central station, multiple transmitting stations and multiple receiving stations, wherein the central station, multiple transmitting stations and multiple receiving stations are connected in sequence by optical fibers to form a ring network; the central station is used to generate a multi-carrier optical radar signal, and divide the multi-carrier optical radar signal into a first multi-carrier optical radar signal and a second multi-carrier optical radar signal. The first multi-carrier optical radar signal is transmitted in sequence along the first direction of the ring network to transmitting station 1, transmitting station 2, ..., transmitting station N, respectively, and a first transmission delay τ is introduced. t1 , τ t2 , ..., τ tN The second multi-carrier optical radar signal is transmitted to receiving station N, ..., receiving station 2, and receiving station 1 in sequence along the second direction of the ring network, respectively introducing a second transmission delay τ rN , ..., τ r2 , τ r1 , the delay of each fiber segment in the ring network satisfies τ ri -τ ti ≠τ rj -τ tj , where 1≤i, j≤N and i≠j, and τ ri -τ ti Much longer than the sum of the transmission delays from the target to the antennas of the multiple transmitting stations and the multiple receiving stations; wherein N is an arbitrary positive integer; the multiple transmitting stations are used to obtain a transmission signal based on the first multi-carrier optical radar signal, and transmit the transmission signal; the multiple receiving stations are used to receive the echo signal from the detected target, sort out the echo signal consistent with the carrier frequency of the transmission signal, generate the optical echo signal together with the second multi-carrier optical radar signal, and transmit the optical echo signal back to the central station along the second direction of the ring network.

[0067] Specifically, the first multi-carrier optical radar signal is transmitted along the first direction of the ring network to transmitting station 1, transmitting station 2, ..., transmitting station N in sequence, which can mean: the first multi-carrier optical radar signal is first transmitted to transmitting station 1 along the first direction of the ring network (i.e., counterclockwise direction), then transmitted to transmitting station 2 via transmitting station 1, ..., and then transmitted to transmitting station N.

[0068] Similarly, the second multi-carrier optical radar signal is transmitted along the second direction of the ring network to receiving station N, ..., receiving station 2, and receiving station 1 in sequence. This can mean that the second multi-carrier optical radar signal is first transmitted to receiving station N along the second direction of the ring network (clockwise direction), then transmitted to receiving station N-1, ..., via receiving station N, and then transmitted to receiving station 2, and then transmitted to receiving station 1.

[0069] Specifically, the multiple transmitting stations may be N transmitting stations, namely, transmitting station 1, transmitting station 2, ..., transmitting station N, where N is any positive integer.

[0070] Similarly, the multiple receiving stations may be N receiving stations, namely, receiving station 1, receiving station 2, ..., receiving station N, where N is any positive integer.

[0071] Specifically, the central station is used to generate carrier wavelengths of λ1, λ2, ..., λ N (When 1≤i, j≤N and i≠j, λ i ≠λ j ) and is divided into two paths by an optical coupler, namely, a first path of multi-carrier optical radar signal and a second path of multi-carrier optical radar signal. Wherein, i and j are any positive integers.

[0072] More specifically, the first multi-carrier optical radar signal is transmitted in a counterclockwise direction along the ring network to transmitting station 1, transmitting station 2, ..., transmitting station N, respectively, introducing a first transmission delay τ t1 , τ t2 , ..., τ tN For example, along the first direction, at each transmitting station, an optical signal of one wavelength is taken out, and the remaining wavelength continues to be transmitted to the next transmitting station; while along the second direction, the transmitting station does not affect signal transmission.

[0073] More specifically, the second multi-carrier optical radar signal is transmitted in the clockwise direction of the ring network to receiving stations N, ..., receiving station 2, and receiving station 1, respectively, and a second transmission delay τ is introduced. rN , ..., τ r2 , τ r1 .

[0074] Furthermore, the delay of each fiber segment in the ring network satisfies τ ri -τ ti ≠τ rj -τ tj (1≤i, j≤N and i≠j), and τ ri -τ ti It is much larger than the sum of the transmission delays from the target to the transmitting station and the receiving station antennas.

[0075] Specifically, a beam-combined de-skewed signal is generated from the beam-combined light-carrying echo signal from the ring network in the clockwise direction and is digitally processed.

[0076] Specifically, the transmitting station i (i=1, 2, ..., N) can be used to obtain the carrier frequency f from the first multi-carrier optical radar signal from the ring network. ci The transmission signal is transmitted and sent out.

[0077] Specifically, receiving station i (i=1, 2, ..., N) can be used to receive the echo signal from the target and sort out the echo signal with a carrier frequency of f ci The echo signal is combined with the second multi-carrier optical radar signal from the ring network to generate an optical echo signal i, which is transmitted back to the central station in the clockwise direction of the ring network.

[0078] Combine the following Figure 1 A central station in the photon-assisted ring-shaped distributed radar detection system is further described.

[0079] In this embodiment, it should be noted that the photon-assisted annular distributed radar detection system may include: a signal generating unit, used to generate a multi-carrier optical radar signal; a first optical fiber circulator, used to couple the multi-carrier optical radar signal into an optical coupler, and couple the optical echo signal from the optical coupler into a signal processing unit; an optical coupler, used to divide the multi-carrier optical radar signal from the first optical fiber circulator into a first multi-carrier optical radar signal and a second multi-carrier optical radar signal, and couple N optical echo signals from the second direction of the annular network into the first optical fiber circulator; a signal processing unit, used to obtain a combined de-skew signal from the N optical echo signals, and digitally process the combined de-skew signal.

[0080] For example, the central station may include, but is not limited to, a signal generating unit, a first optical fiber circulator, an optical coupler, and a signal processing unit.

[0081] Specifically, the signal generating unit is used to generate a multi-carrier optical radar signal.

[0082] Specifically, the first optical fiber circulator is used to couple the multi-carrier optical radar signal from port 1 into the optical coupler corresponding to port 2, and couple the N-channel optical echo signals from the optical coupler from port 2 into the signal processing unit corresponding to port 3;

[0083] Specifically, the optical coupler is used to split the multi-carrier optical radar signal from port 2 of the optical fiber circulator into two paths, and couple the N paths of optical echo signals from the ring network in the clockwise direction into port 2 of the optical fiber circulator;

[0084] Specifically, the signal processing unit is used to obtain a beam-combined de-skewed signal from N optical carrier echo signals and perform digital processing on the signal.

[0085] Further, in this embodiment, it should be noted that the photon-assisted annular distributed radar detection system may include: a signal generating unit including: a laser array for outputting N wavelengths of λ1, λ2, ..., λ NA combined optical carrier; an optical comb generator, used to generate N optical frequency combs using the combined optical carrier, the comb teeth of each optical frequency comb are uniformly spaced, and the wavelength range covered by each optical frequency comb does not overlap; a signal source, used to generate a linear frequency modulation signal; a modulator, used to modulate the linear frequency modulation signal onto each comb tooth of the N optical frequency combs to generate a multi-carrier optical radar signal.

[0086] For example, the signal generating unit may further include, but is not limited to: a laser array, a light comb generator, a signal source, and a modulator.

[0087] Specifically, the laser array is used to output N channels with wavelengths of λ1, λ2, ..., λ N The combined optical carrier.

[0088] Specifically, the optical comb generator is used to generate N optical frequency combs using a combined optical carrier, the teeth of each optical frequency comb are spaced uniformly, and the wavelength ranges covered by each optical frequency comb do not overlap.

[0089] Specifically, the signal source is used to generate a linear frequency modulation signal.

[0090] Specifically, the modulator is used to modulate the linear frequency modulation signal onto each comb tooth of N optical frequency combs to generate a multi-carrier optical radar signal.

[0091] Furthermore, in the present embodiment, it should be noted that the photon-assisted annular distributed radar detection system may include: a signal processing unit, including: a first photodetector, used to perform photoelectric conversion on N optical echo signals to realize parallel de-skew processing of the N optical echo signals, and obtain a combined de-skewed signal corresponding to multiple echo signals; an analog-to-digital converter, used to perform analog-to-digital conversion on the combined de-skewed signal; and a digital processor, used to perform digital domain processing on the combined de-skewed signal after the analog-to-digital conversion.

[0092] For example, the signal processing unit may further include, but is not limited to, a first photodetector and an analog-to-digital converter.

[0093] Specifically, the first photodetector is used to perform photoelectric conversion on the N-channel light-carrying echo signal, and implement parallel de-skewing processing on the N-channel light-carrying echo signal to obtain the signal corresponding to the carrier frequency f. c1 、f c2 ,……,f cN The combined and de-skewed signal of the echo signal.

[0094] Specifically, the analog-to-digital converter is used to perform analog-to-digital conversion on the beam-combining and de-skewed signal; and the digital processor is used to perform digital domain processing on the beam-combining and de-skewed signal after the analog-to-digital conversion.

[0095] Combine the following Figure 1 and Figure 2Multiple transmitting stations in the photon-assisted ring-shaped distributed radar detection system are described together.

[0096] Figure 2 A schematic diagram of the structure of a transmitting station in a photon-assisted annular distributed radar detection system provided in one embodiment of the present invention.

[0097] In this embodiment, it should be noted that the photon-assisted annular distributed radar detection system may include: a plurality of transmitting stations, including: a first wavelength division multiplexer, a second wavelength division multiplexer and a second optical fiber circulator, wherein the second optical fiber circulator is arranged between the first wavelength division multiplexer and the second wavelength division multiplexer; the first wavelength division multiplexer is used to split the multi-carrier optical radar signal from the first direction of the annular network according to different carrier wavelengths, and the carrier wavelength is λ i+1 , ..., λ N The optical radar signal is coupled into the second wavelength division multiplexer, and the carrier wavelength corresponding to the transmitting station i is λ i The optical radar signal is coupled into the second optical fiber circulator, and the optical radar signal from the second wavelength division multiplexer and the carrier wavelength corresponding to the transmitting station i from the second optical fiber circulator are coupled into the second optical fiber circulator, and the optical radar signal from the second wavelength division multiplexer and the carrier wavelength corresponding to the transmitting station i ... i The optical echo signal of is combined and coupled into the ring network for transmission in the second direction; the second wavelength division multiplexer is used to split the multi-carrier optical radar signal and the combined optical echo signal from the second direction of the ring network according to different carrier wavelengths, and the carrier wavelength corresponding to the transmitting station i is λ i The optical radar signal is coupled into the second optical fiber circulator; at the same time, the carrier wavelength λ from the first wavelength division multiplexer is coupled into the second optical fiber circulator; i+1 , ..., λ N The optical radar signals are combined and coupled into the ring network to be transmitted along the first direction.

[0098] In addition, in this embodiment, it is also necessary to explain that the photon-assisted annular distributed radar detection system may include: a plurality of transmitting stations, and also include: a second photoelectric detector for detecting a carrier wave length λ corresponding to the transmitting station i. i The optical radar signal is photoelectrically converted, the comb tooth interval and the carrier frequency and bandwidth of the linear frequency modulation signal are set, and no less than N pre-transmission signals of different frequency bands are obtained from the beat frequencies of different modulation sidebands of the optical frequency comb; the first electrical filter is used to select the transmission signal from the pre-transmission signal and output it to the first antenna; the first antenna is used to transmit the transmission signal to the detection target.

[0099] For example, the plurality of transmitting stations may include, but are not limited to: wavelength division multiplexer 1, wavelength division multiplexer 2, a second optical fiber circulator, a second photodetector, a first electrical filter, and a first antenna.

[0100] Specifically, the wavelength division multiplexer 1 is used to convert the multi-carrier optical radar signal (corresponding to the carrier wavelength λ) from the ring network in the counterclockwise direction to i , i+1 , ..., λ N ) according to the different carrier wavelengths, where the carrier wavelength is λ i+1 , ..., λ N The optical radar signal is coupled into the wavelength division multiplexer 2, and the carrier wavelength is λ i The optical radar signal is coupled into the 2 port of the circulator; at the same time, the carrier wavelengths of λ1, ..., λ i-1 , i+1 , ..., λ N The wavelength of the optical radar signal and the carrier from port 2 of the circulator is λ i The optical echo signal i is combined into a beam, coupled into the ring network and transmitted in a clockwise direction.

[0101] Specifically, the wavelength division multiplexer 2 is used to convert the multi-carrier optical radar signals (corresponding to the carrier wavelengths λ1, . . . , λ i ) and the combined beam carrying echo signal (corresponding to the carrier wavelength λ i+1 , ..., λ N ) according to the different carrier wavelengths, where the carrier wavelength is λ i The optical radar signal is coupled into port 1 of the circulator; at the same time, the carrier wavelength λ from wavelength division multiplexer 1 is coupled into port 1 of the circulator; i+1 , ..., λ N The optical radar signals are combined, coupled into the ring network and transmitted in a counterclockwise direction.

[0102] Specifically, the second optical fiber circulator is used to convert the carrier wavelength λ from the wavelength division multiplexer 1 to i The optical radar signal is coupled into the second photodetector corresponding to port 3, and at the same time, the carrier wavelength λ from wavelength division multiplexer 2 is coupled from port 1. i The optical radar signal is coupled into the wavelength division multiplexer 1 corresponding to port 2.

[0103] Specifically, the second photodetector is used to detect the carrier wavelength λ i The optical radar signal is photoelectrically converted, the comb tooth interval and the carrier frequency and bandwidth of the linear frequency modulation signal are reasonably set, and no less than N pre-transmitted signals of different frequency bands can be obtained from the different modulation sideband beat frequencies of the optical frequency comb. The spectrum of each band does not overlap, and the carrier frequencies are f c1 、f c2 ,……,f cN , the bandwidth is an integer multiple of the linear frequency modulation signal bandwidth.

[0104] Specifically, the first electric filter is used to select a carrier frequency f from the pre-transmitted signal. ci The transmitted signal is output to the antenna.

[0105] Specifically, the first antenna is used to transmit the carrier frequency f ci The transmission signal is transmitted to the target.

[0106] Combine the following Figure 1 and Figure 3 A plurality of receiving stations in the photon-assisted ring-shaped distributed radar detection system are described together.

[0107] Figure 3 A schematic diagram of the structure of a receiving station in a photon-assisted ring-shaped distributed radar detection system provided by an embodiment of the present invention.

[0108] In this embodiment, it should be noted that the photon-assisted annular distributed radar detection system may include: a plurality of receiving stations, including: a third wavelength division multiplexer, for splitting the multi-carrier optical radar signal and the combined optical echo signal from the second direction of the annular network according to different carrier wavelengths, and at the same time splitting the carrier wavelength from the fourth wavelength division multiplexer into ... i+1 , ..., λ N The optical radar signal is combined and coupled into the ring network for transmission in the first direction; a fourth wavelength division multiplexer is used to combine the carrier wavelength λ from the first direction of the ring network i+1 , ..., λ N The optical radar signal is split into two beams, and the optical echo signal i corresponding to the receiving station i from the optical filter and the carrier wavelengths λ1, ..., λ from the third wavelength division multiplexer are split into two beams. i-1 The optical radar signal and the carrier wavelength are i+1 , ..., λ N The optically-carrying echo signals are combined into a beam and coupled into the ring network for transmission in the second direction.

[0109] In addition, in this embodiment, it should be noted that the photon-assisted annular distributed radar detection system may include: a plurality of receiving stations, and also include: a second antenna for receiving an echo signal from a target; a second electrical filter for sorting the echo signal; a modulator for modulating the echo signal to a carrier wavelength λ corresponding to the receiving station i. i The optical radar signal is applied to obtain an optical echo modulation signal; and the optical filter is used to select a desired modulation sideband from the optical echo modulation signal to obtain an optical echo signal i corresponding to the receiving station i.

[0110] For example, the receiving station may include, but is not limited to, a second antenna, a second electrical filter, a wavelength division multiplexer 3, a modulator, an optical filter, and a wavelength division multiplexer 4.

[0111] Specifically, the second antenna is used to receive an echo signal from the target.

[0112] Specifically, the second electric filter is used to select the carrier frequency f from the target echo signal. ci echo signal.

[0113] Specifically, the wavelength division multiplexer 3 is used to convert the multi-carrier optical radar signals (corresponding to the carrier wavelengths λ1, . . . , λ i ) and the combined beam carrying echo signal (corresponding to the carrier wavelength λ i+1 , ..., λ N ) according to the different splitting of the carrier wavelength; at the same time, the carrier wavelength from the wavelength division multiplexer 4 is λ i+1 , ..., λ N The optical radar signals are combined, coupled into the ring network and transmitted in a counterclockwise direction.

[0114] Specifically, the modulator is used to convert the carrier frequency f ci The echo signal is modulated to a carrier wavelength of λ i The optical radar signal is then applied to obtain the optical echo modulation signal i.

[0115] Specifically, the optical filter is used to select a desired modulation sideband from the light-carrying echo modulation signal i to obtain the light-carrying echo signal i.

[0116] Specifically, the wavelength division multiplexer 4 is used to convert the carrier wavelength λ from the counterclockwise direction of the ring network into i+1 , ..., λ N At the same time, the optical echo signal i from the optical filter and the carrier wavelength from the wavelength division multiplexer 3 are λ1, ..., λ i-1 The optical radar signal and carrier wavelength are i+1 , ..., λ N The optical echo signals are combined into a beam, coupled into the ring network and transmitted in a clockwise direction.

[0117] Combine the following Figure 4 The photon-assisted annular distributed radar detection method provided by the present invention is described. The photon-assisted annular distributed radar detection method described below and the photon-assisted annular distributed radar detection system described above can be referred to each other.

[0118] Figure 4 A flowchart of the steps of a photon-assisted annular distributed radar detection method provided by one embodiment of the present invention.

[0119] Since the photon-assisted annular distributed radar detection system provided in the embodiment of the present invention can be used to execute the photon-assisted annular distributed radar detection method of the following embodiments, its working principle and beneficial effects are similar, so they will not be described in detail here. For specific contents, please refer to the introduction of the above embodiments.

[0120] In this embodiment, it should also be noted that the photon-assisted annular distributed radar detection method may include: using the above-mentioned photon-assisted annular distributed radar detection system to perform radar detection.

[0121] In this embodiment, it should also be noted that the photon-assisted annular distributed radar detection method may include:

[0122] S1: A central station, multiple transmitting stations, and multiple receiving stations are connected in sequence by optical fibers to form a ring network; a multi-carrier optical radar signal is generated in the central station, and the multi-carrier optical radar signal is divided into a first multi-carrier optical radar signal and a second multi-carrier optical radar signal; the first multi-carrier optical radar signal is transmitted in sequence along a first direction of the ring network to transmitting station 1, transmitting station 2, ..., transmitting station N, and a first transmission delay τ is introduced respectively. t1 , τ t2 , ..., τ tN ; The second multi-carrier optical radar signal is transmitted to receiving station N, ..., receiving station 2, and receiving station 1 in sequence along the second direction of the ring network, respectively introducing a second transmission delay τ rN , ..., τ r2 , τ r1 , the delay of each fiber segment in the ring network satisfies τ ri -τ ti ≠τ rj -τ tj , where 1≤i, j≤N and i≠j, and τ ri -τ ti Much larger than the sum of the transmission delays from the target to the antennas of multiple transmitting stations and multiple receiving stations; where N is an arbitrary positive integer;

[0123] S2: obtaining a transmission signal based on the first multi-carrier optical radar signal in multiple transmission stations, and transmitting the transmission signal;

[0124] S3: Receive the echo signal from the detected target, select the echo signal that is consistent with the carrier frequency of the transmitted signal, generate an optical echo signal together with the second multi-carrier optical radar signal, and transmit the optical echo signal back to the central station along the second direction of the ring network.

[0125] In addition, in the present invention, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the statement "comprise a ..." do not exclude the presence of other identical elements in the process, method, article or device including the elements.

[0126] In addition, in the present invention, the description with reference to the terms "embodiment", "present embodiment", "another embodiment", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine different embodiments or examples described in this specification and the features of different embodiments or examples, unless they are contradictory.

[0127] 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

1. A photon-assisted annular distributed radar detection system, characterized in that: include: A central station, a plurality of transmitting stations and a plurality of receiving stations, wherein the central station, the plurality of transmitting stations and the plurality of receiving stations are sequentially connected by optical fibers to form a ring network; The central station is used to generate a multi-carrier optical radar signal, divide the multi-carrier optical radar signal into a first multi-carrier optical radar signal and a second multi-carrier optical radar signal, and transmit the first multi-carrier optical radar signal in sequence along the first direction of the ring network to transmitting station 1, transmitting station 2, ..., transmitting station N, respectively, introducing a first transmission delay τ t1 , τ t2 , ..., τ tN The second multi-carrier optical radar signal is transmitted to receiving station N, ..., receiving station 2, and receiving station 1 in sequence along the second direction of the ring network, respectively introducing a second transmission delay τ rN , ..., τ r2 , τ r1 , the delay of each fiber segment in the ring network satisfies τ ri -τ ti ≠τ rj -τ tj , where 1≤i, j≤N and i≠j, and τ ri -τ ti Much greater than the sum of the transmission delays from the target to the antennas of the multiple transmitting stations and the multiple receiving stations; wherein N is an arbitrary positive integer; The multiple transmitting stations are used to obtain a transmission signal based on the first multi-carrier optical radar signal, and transmit the transmission signal; The multiple receiving stations are used to receive echo signals from the detection target, select the echo signals that are consistent with the carrier frequency of the transmission signal, generate optical echo signals together with the second multi-carrier optical radar signal, and transmit the optical echo signals back to the central station along the second direction of the ring network. The central station comprises: The signal generating unit is used to generate the multi-carrier optical radar signal; The first optical fiber circulator is used for coupling the multi-carrier optical radar signal into an optical coupler, and coupling the optical echo signal from the optical coupler into a signal processing unit; The optical coupler is used to divide the multi-carrier optical radar signal from the first optical fiber circulator into the first multi-carrier optical radar signal and the second multi-carrier optical radar signal, and couple N optical echo signals from the second direction of the ring network into the first optical fiber circulator; The signal processing unit is used to obtain a beam-combined de-skew signal from N optical carrier echo signals, and digitally process the beam-combined de-skew signal. The plurality of transmitting stations include: a first wavelength division multiplexer, a second wavelength division multiplexer and a second optical fiber circulator, wherein the second optical fiber circulator is arranged between the first wavelength division multiplexer and the second wavelength division multiplexer; The first wavelength division multiplexer is used to split the multi-carrier optical radar signal from the first direction of the ring network according to different carrier wavelengths, and the carrier wavelength is λ i+1 , ..., λ N The optical radar signal is coupled into the second wavelength division multiplexer, and the carrier wavelength corresponding to the transmitting station i is λ i The optical radar signal from the second wavelength division multiplexer and the carrier wavelength corresponding to the transmitting station i from the second optical fiber circulator are coupled into the second optical fiber circulator, and the ... are coupled into the second optical fiber circulator, and the carrier wavelength corresponding to the transmitting station i is coupled into the second optical fiber circulator, and the carrier wavelength corresponding to the transmitting station i is coupled into the second optical fiber circulator i The optically-carrying echo signals are combined into a beam and coupled into the ring network for transmission along a second direction; The second wavelength division multiplexer is used to split the multi-carrier optical radar signal and the combined optical echo signal from the second direction of the ring network according to different carrier wavelengths, and the carrier wavelength corresponding to the transmitting station i is λ i The optical radar signal is coupled into the second optical fiber circulator; at the same time, the carrier wavelength λ from the first wavelength division multiplexer is coupled into the second optical fiber circulator; i+1 , ..., λ N The optical radar signals are beam-combined and coupled into the ring network to be transmitted along the first direction.

2. The photon-assisted annular distributed radar detection system according to claim 1, characterized in that: The plurality of transmitting stations also include: The second photoelectric detector is used to detect the carrier wavelength λ corresponding to the transmitting station i. i The optical radar signal is photoelectrically converted, the comb tooth interval and the carrier frequency and bandwidth of the linear frequency modulation signal are set, and pre-transmitted signals of no less than N different frequency bands are obtained from the beat frequencies of different modulation sidebands of the optical frequency comb; A first electrical filter, used for selecting a transmission signal from the pre-transmission signal and outputting it to the first antenna; The first antenna is used to transmit the transmission signal to the detection target.

3. The photon-assisted annular distributed radar detection system according to claim 1, characterized in that: The plurality of receiving stations include: The third wavelength division multiplexer is used to split the multi-carrier optical radar signal and the combined optical echo signal from the second direction of the ring network according to different carrier wavelengths, and at the same time split the carrier wavelength from the fourth wavelength division multiplexer into two different wavelengths. i+1 , ..., λ N The optical radar signal is combined into a beam and coupled into the ring network for transmission along a first direction; The fourth wavelength division multiplexer is used to convert the carrier wavelength from the first direction of the ring network into i+1 , ..., λ N The optical radar signal is split into two beams, and the optical echo signal i corresponding to the receiving station i from the optical filter and the carrier wavelengths λ1, ..., λ from the third wavelength division multiplexer are split. i-1 The optical radar signal and the carrier wavelength are i+1 , ..., λ N The optically-carrying echo signals are combined into a beam and coupled into the ring network to be transmitted along the second direction.

4. The photon-assisted annular distributed radar detection system according to claim 3, characterized in that: The plurality of receiving stations further comprises: a second antenna, for receiving an echo signal from a target; a second electric filter, used for sorting the echo signal; A modulator is used to modulate the echo signal to a carrier wave with a wavelength λ corresponding to the receiving station i. i on the optical radar signal to obtain an optical echo modulation signal; The optical filter is used to select a desired modulation sideband from the light-carrying echo modulation signal to obtain the light-carrying echo signal i corresponding to the receiving station i.

5. The photon-assisted annular distributed radar detection system according to claim 1, characterized in that: The signal generating unit comprises: The laser array is used to output N wavelengths of λ1, λ2, ..., λ N The combined optical carrier; An optical comb generator, used to generate N optical frequency combs using the combined optical carrier, the teeth of each optical frequency comb having a consistent interval, and the wavelength ranges covered by each optical frequency comb do not overlap; A signal source, used for generating a linear frequency modulation signal; A modulator is used to modulate the linear frequency modulation signal onto each comb tooth of the N optical frequency combs to generate the multi-carrier optical radar signal.

6. The photon-assisted annular distributed radar detection system according to claim 1, characterized in that: The signal processing unit comprises: a first photoelectric detector, configured to perform photoelectric conversion on the N optical echo signals to implement parallel de-skewing of the N optical echo signals and obtain the combined de-skewing signal corresponding to the multi-path echo signals; an analog-to-digital converter, used for performing analog-to-digital conversion on the beam-combining de-skew signal; A digital processor is used to perform digital domain processing on the beam-combined de-skewed signal after the analog-to-digital conversion.

7. A photon-assisted annular distributed radar detection method, characterized in that: include: The photon-assisted annular distributed radar detection system described in any one of claims 1 to 6 is used to perform target detection.

8. The photon-assisted annular distributed radar detection method according to claim 7, characterized in that: include: The central station, multiple transmitting stations and multiple receiving stations are connected in sequence by optical fibers to form a ring network; A multi-carrier optical radar signal is generated in the central station, and the multi-carrier optical radar signal is divided into a first multi-carrier optical radar signal and a second multi-carrier optical radar signal. The first multi-carrier optical radar signal is transmitted in sequence along the first direction of the ring network to transmitting station 1, transmitting station 2, ..., transmitting station N, and a first transmission delay τ is introduced respectively. t1 , τ t2 , ..., τ tN The second multi-carrier optical radar signal is transmitted to receiving station N, ..., receiving station 2, and receiving station 1 in sequence along the second direction of the ring network, respectively introducing a second transmission delay τ rN , ..., τ r2 , τ r1 , the delay of each fiber segment in the ring network satisfies τ ri -τ ti ≠τ rj -τ tj , where 1≤i, j≤N and i≠j, and τ ri -τ ti Much greater than the sum of the transmission delays from the target to the antennas of the multiple transmitting stations and the multiple receiving stations; wherein N is an arbitrary positive integer; In the multiple transmitting stations, a transmission signal is obtained based on the first multi-carrier optical radar signal, and the transmission signal is transmitted; The echo signals from the detected targets are received in the multiple receiving stations, and the echo signals consistent with the carrier frequency of the transmitted signal are selected, and the echo signals are used together with the second multi-carrier optical radar signal to generate an optical echo signal, and the optical echo signal is transmitted back to the central station along the second direction of the ring network.

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