阅读说明：本技术 一种微波光子雷达通信一体化系统及方法 (Microwave photon radar communication integrated system and method ) 是由 郑小平 薛竹君 李尚远 薛晓晓 于 2021-06-16 设计创作，主要内容包括：本发明属于雷达通信一体化技术领域,尤其涉及一种微波光子雷达通信一体化系统及方法。本发明系统在一个具有选模、放大和光纤储能器件的传统OEO中插入光多维度调控模块,对光的频率、相位、幅度、偏振四个维度,进行灵活高速的控制和充分的复用,在射频频段实现雷达通信功能相对独立的并行融合。本发明方法利用OEO提供射频本振,优化了一体化信号的相位噪声,解决了对于高频外部源的依赖问题；通过在OEO环路中对光进行多维度调控和复用,解决了高速通信带来的雷达距离模糊问题。本发明方法可实现的雷达和通信性能为：最大探测距离通信容量距离分辨率可灵活改变M、N、τ的数值进行性能优化,更好地满足不同应用场景下对于雷达和通信性能的需求。(The invention belongs to the technical field of radar communication integration, and particularly relates to a microwave photon radar communication integration system and method. The system inserts the optical multi-dimensional regulation and control module into a traditional OEO with a mode selection device, an amplification device and an optical fiber energy storage device, flexibly and quickly controls four dimensions of optical frequency, phase, amplitude and polarization and fully multiplexes, and realizes the parallel integration of the radar communication function in a radio frequency band. The method provided by the invention utilizes OEO to provide the radio frequency local oscillator, optimizes the phase noise of the integrated signal and solves the problem of dependence on a high-frequency external source; by carrying out multi-dimensional regulation and multiplexing on light in the OEO loop, the problem of radar distance ambiguity caused by high-speed communication is solved. The radar and communication performance which can be realized by the method of the invention is as follows: maximum detection distance Communication capacity Distance resolution The values of M, N and tau can be flexibly changed to optimize performance, and the requirements on radar and communication performance under different application scenes can be better met.)

1. A microwave photon radar communication integrated system is characterized by comprising: the device comprises a laser source, an optical multi-dimensional modulator, an optical coupler, a polarization beam splitter, a balance detector, a long optical fiber, a photoelectric detector, an amplifier, a filter, an electric coupler, an orthogonal mixer, a transmitting antenna and a receiving antenna; wherein the laser, the optical multi-dimensional modulator, the long optical fiber, the photoelectric detector, the amplifier, the filter and the electric coupler form a photoelectric oscillator;

the output of the laser source is connected with an optical input port of an optical multi-dimensional regulator, the digital input port of the optical multi-dimensional regulator is connected with one two-path digital code source, a radio frequency input port of the optical multi-dimensional regulator is connected with a single-frequency oscillation signal of a photoelectric oscillator, the digital signal sent by the two-path digital code source and the single-frequency oscillation signal of the photoelectric oscillator are used for regulating and multiplexing the frequency, the amplitude, the phase and the polarization of laser sent by the laser source through the optical multi-dimensional regulator, and then are divided into two paths of signals by an optical coupler, one path of output signal of the optical coupler is connected with the input of the electric coupler after sequentially passing through a long optical fiber, a photoelectric detector, an amplifier and a filter, and one path of output signal of the electric coupler is connected with the radio frequency input port of the optical multi-dimensional regulator to form a closed photoelectric oscillator; the other path of output signal of the optical coupler passes through the polarization beam splitter and is input into the balance detector to obtain a radar communication integrated signal, the radar communication integrated signal is transmitted through the transmitting antenna, the receiving antenna receives the radar communication integrated signal, the radar communication integrated signal and the other path of output signal of the electric coupler in the photoelectric oscillator are transmitted to the orthogonal frequency mixer together, the frequency-mixed signal is transmitted to the digital signal processing module, the digital signal processing module processes and demodulates the frequency-mixed signal to obtain distance information and communication information of a radar, and radar communication integration is achieved.

2. The integrated microwave photonic radar and communication system as claimed in claim 1, wherein the optical multi-dimensional modulator comprises a 90-degree bridge and a dual-polarization dual-parallel modulator, the single-frequency oscillation signal of the optoelectronic oscillator loop is connected to the 90-degree bridge, two output signals of the 90-degree bridge are respectively applied to two parallel mach-zehnder modulators (MZMs) in the X-polarization direction, two digital code source inputs are applied to two parallel mach-zehnder modulators in the Y-polarization direction, and two lights in the X-polarization direction and the Y-polarization direction are combined into one light by a polarization beam combiner to serve as the output of the optical multi-dimensional modulator.

3. A microwave photon radar communication integration method is characterized by comprising the following steps:

(1) determining the center frequency of a filter in the photoelectric oscillator according to the working frequency band of radar communication integration; photoelectric oscillationThe radio frequency signal in the device passes through a 90-degree electric bridge to drive a double parallel modulator which works in a single-sideband modulation mode in the X polarization direction to generate a single-sideband spectrum E in the X polarization direction_xThe single side band spectrum E_xThe frequency interval between the optical carrier and the radio frequency modulation sideband in the medium is the oscillation frequency omega of the photoelectric oscillator_e；

(2) Setting bits of communication information to c_IAnd c_QDesigning a radar communication integrated signal: namely, two paths of bipolar coded pulse compression signals r are adopted_I(t) and r_Q(t) bipolar coding length M and N, bipolar coding symbol period τ, communication information bit c to be set_IAnd c_QModulated on a pulse-compressed signal r_I(t) and r_Q(t) obtaining two paths of radar communication integrated signals rc on the overall polarity_I(t) and rc_Q(t)；

(3) Rc according to step (2)_I(t) and rc_Q(t) driving a dual-parallel modulator operating in a suppressed carrier modulation mode in the Y polarization direction to produce a baseband spectrum E in the Y polarization direction_y；

(4) Using an optical coupler to input a part of signals of the optical multi-dimensional modulator into a polarization beam splitter, so that two output signals of the polarization beam splitter are respectively E_x+E_yAnd E_x-E_yThe two output signals are subjected to independent beat frequency subtraction in a balanced detector to generate a radio frequency radar communication integrated signal E without carrier leakage and image frequency interference_xE_y ^*The radar communication integrated signal E_xE_y ^*Transmitting through an antenna;

(5) radar communication integrated signal E of step (4)_xE_y ^*After being received by an antenna, the two signals are subjected to orthogonal frequency mixing and analog-to-digital conversion, and then pulse compression is carried out on the two signals in a digital signal processing module to obtain communication information and two paths of radar echo delay information delta tau_IAnd Δ τ_QThe digital signal processing module obtains real radar echo delay delta tau through data fusion, and the microwave photon radar is realizedAnd (4) communication integration.

Technical Field

The invention belongs to the technical field of radar communication integration, and particularly relates to a microwave photon radar communication integration system and method.

Background

With the rise of the intelligent transportation concept, the vehicle needs to perform instant information interaction with other cooperation platforms while performing high-precision detection on the environment. Under the promotion of the necessity of reducing system power consumption and hardware redundancy, under the feasible support that the working frequency and hardware structures of radar and communication tend to be consistent, the realization of the function integration and the collaborative coexistence of radar and communication on the same platform becomes a research hotspot. In recent years, a plurality of radar communication integrated system structures based on ideas such as time division, frequency division, space division, code division and the like are proposed, and the core is to allocate and multiplex different types of resources, so that interference is inevitably generated and the performance is influenced. The common waveform is subjected to software level fusion and decoupling through signal design and digital processing, mutual interference is avoided, and efficiency is maximized. The integrated common waveform needs to meet the requirements of high resolution of the radar and high speed and effectiveness of communication at the same time, but due to the limitation of an electronic bottleneck, signals generated by a digital-to-analog converter cannot cover high frequency and large bandwidth, and the resolution of the radar is influenced. Electronic frequency doubling can degrade phase noise and affect communication quality and receiver sensitivity. The high loss of cable transmission and electromagnetic interference are also challenges for the wide range coverage of smart urban networks. Microwave photonics introduces the advantages of high frequency, large bandwidth, electromagnetic interference immunity and the like of an optical domain into the electronic field, and provides support for high-quality integrated signal generation.

In the existing microwave photon radar communication integrated system, communication functions are embedded in the traditional radar pulse waveform through cascade electro-optical modulation, so that the independence of the two functions is destroyed, and the compromise exists between radar and communication performance. Meanwhile, in order to meet the frequency band requirement of the existing automobile radar, an external microwave source is used as a local oscillator, and the up-conversion of the integrated signal is indispensable. However, this increases the cost and complexity of the system, and the additional phase noise causes the integration performance to deteriorate, and also causes the system not to be completely separated from the limitation of the electrical bottleneck. An Optoelectronic Oscillator (OEO for short) is a typical application of a photonic technology in the field of microwave oscillation signal generation, and an Optoelectronic hybrid resonant cavity provides characteristics of high Q value, low phase noise and Optoelectronic dual output, and can realize corresponding radio-frequency signal output through broadband high-speed multi-dimensional regulation of an optical domain. Therefore, the performance compromise between communication and radar and the dependence on high-quality external microwave sources exist in the prior integrated system technology, and the cost, the complexity and the combined working performance of the system are influenced.

Disclosure of Invention

The invention aims to provide a microwave photon radar communication integrated system and a method, which utilize OEO to provide radio frequency local oscillation, optimize the phase noise of integrated signals and solve the problem of dependence of the prior art on a high-frequency external source; by carrying out multi-dimensional regulation and multiplexing on light in an OEO loop, the problem of radar distance ambiguity brought by high-speed communication is solved.

The invention provides a microwave photon radar communication integrated system, which comprises: the device comprises a laser source, an optical multi-dimensional modulator, an optical coupler, a polarization beam splitter, a balance detector, a long optical fiber, a photoelectric detector, an amplifier, a filter, an electric coupler, an orthogonal mixer, a transmitting antenna and a receiving antenna; wherein the laser, the optical multi-dimensional modulator, the long optical fiber, the photoelectric detector, the amplifier, the filter and the electric coupler form a photoelectric oscillator;

the output of the laser source is connected with an optical input port of an optical multi-dimensional regulator, the digital input port of the optical multi-dimensional regulator is connected with one two-path digital code source, a radio frequency input port of the optical multi-dimensional regulator is connected with a single-frequency oscillation signal of a photoelectric oscillator, the digital signal sent by the two-path digital code source and the single-frequency oscillation signal of the photoelectric oscillator are used for regulating and multiplexing the frequency, the amplitude, the phase and the polarization of laser sent by the laser source through the optical multi-dimensional regulator, and then are divided into two paths of signals by an optical coupler, one path of output signal of the optical coupler is connected with the input of the electric coupler after sequentially passing through a long optical fiber, a photoelectric detector, an amplifier and a filter, and one path of output signal of the electric coupler is connected with the radio frequency input port of the optical multi-dimensional regulator to form a closed photoelectric oscillator; the other path of output signal of the optical coupler passes through the polarization beam splitter and is input into the balance detector to obtain a radar communication integrated signal, the radar communication integrated signal is transmitted through the transmitting antenna, the receiving antenna receives the radar communication integrated signal, the radar communication integrated signal and the other path of output signal of the electric coupler in the photoelectric oscillator are transmitted to the orthogonal frequency mixer together, the frequency-mixed signal is transmitted to the digital signal processing module, the digital signal processing module processes and demodulates the frequency-mixed signal to obtain distance information and communication information of a radar, and radar communication integration is achieved.

The invention provides a microwave photon radar communication integration method, which comprises the following steps:

(1) determining the center frequency of a filter in the photoelectric oscillator according to the working frequency band of radar communication integration; the radio frequency signal in the photoelectric oscillator passes through a 90-degree bridge to drive a double-parallel modulator which works in a single-sideband modulation mode in the X polarization direction to generate a single-sideband spectrum E in the X polarization direction_xThe single side band spectrum E_xThe frequency interval between the optical carrier and the radio frequency modulation sideband in the medium is the oscillation frequency omega of the photoelectric oscillator_e；

(2) Setting bits of communication information to c_IAnd c_QDesigning a radar communication integrated signal: namely, two paths of bipolar coded pulse compression signals r are adopted_I(t) and r_Q(t) bipolar coding length M and N, bipolar coding symbol period τ, communication information bit c to be set_IAnd c_QModulated on a pulse-compressed signal r_I(t) and r_Q(t) obtaining two paths of radar communication integrated signals rc on the overall polarity_I(t) and rc_Q(t)；

(3) Rc according to step (2)_I(t) and rc_Q(t) driving a dual-parallel modulator operating in a suppressed carrier modulation mode in the Y polarization direction to produce a baseband spectrum E in the Y polarization direction_y；

(4) Using an optical coupler to input a part of signals of the optical multi-dimensional modulator into a polarization beam splitter, so that two output signals of the polarization beam splitter are respectively E_x+E_yAnd E_x-E_yThe two output signals are subjected to independent beat frequency subtraction in a balanced detector to generate a radio frequency radar communication integrated signal E without carrier leakage and image frequency interference_xE_y ^*The radar communication integrated signal E_xE_y ^*Transmitting through an antenna;

(5) radar communication integrated signal E of step (4)_xE_y ^*After being received by an antenna, the two signals are subjected to orthogonal frequency mixing and analog-to-digital conversion, and then pulse compression is carried out on the two signals in a digital signal processing module to obtain communication information and two paths of radar echo delay information delta tau_IAnd Δ τ_QAnd the digital signal processing module obtains the real radar echo delay delta tau through data fusion, and realizes the integration of microwave photon radar communication.

The invention provides a microwave photon radar communication integrated system and a method, which has the characteristics and advantages that:

according to the microwave photon radar communication integrated system, an optical multi-dimensional regulation and control module is inserted into a traditional OEO with a mode selection device, an amplification device and an optical fiber energy storage device, four dimensions of frequency, phase, amplitude and polarization of light are flexibly and quickly controlled and fully multiplexed, and the parallel integration of the radar communication function is realized in a radio frequency band relatively independently. According to the microwave photon radar communication integration method, the OEO is used for providing the radio frequency local oscillator, so that the phase noise of an integrated signal is optimized, and the problem of dependence on a high-frequency external source is solved; through multi-dimensional regulation and multiplexing of light in an OEO loop, the problem of radar distance ambiguity caused by high-speed communication is solved, and the traditional method I is brokenThe performance tradeoff that exists in the materialization approach is such that both functions can be designed and optimized independently; because the OEO has the characteristics of broadband tunability and independence of phase noise and frequency, the OEO breaks through the combination performance limitation by combining with a corresponding signal receiving and processing method, eliminates the radar distance ambiguity problem caused by high-speed communication, and finally realizes a high-quality and reconfigurable integrated system. The microwave photon radar communication integrated method can realize the radar and communication performances as follows: maximum detection distanceCommunication capacityDistance resolutionThe values of M, N and tau can be flexibly changed for performance optimization, so as to better meet the requirements on radar and communication performance in different application scenarios.

Drawings

Fig. 1 is a schematic structural diagram of a microwave photonic radar communication integrated system according to the present invention.

Fig. 2 is a schematic diagram of an optical multi-dimensional modulator in the system shown in fig. 1.

Fig. 3 is a schematic diagram of the spectral transformation in the integrated signal generation process.

Figure 4 is a graph of the phase noise curve of an OEO.

Fig. 5 is a diagram illustrating the results of a radar range profile implemented in an embodiment of the present invention.

Fig. 6 is a schematic diagram of a communication EVM curve implemented by an embodiment of the present invention.

Detailed Description

The microwave photon radar communication integrated system provided by the invention has the structure shown in figure 1, and comprises: the device comprises a laser source, an optical multi-dimensional modulator, an optical coupler, a polarization beam splitter, a balance detector, a long optical fiber, a photoelectric detector, an amplifier, a filter, an electric coupler, an orthogonal mixer, a transmitting antenna and a receiving antenna; wherein the laser, the optical multi-dimensional modulator, the long optical fiber, the photoelectric detector, the amplifier, the filter and the electric coupler form a photoelectric oscillator;

wherein, the output of the laser source is connected with the optical input port of the optical multi-dimensional controller, the digital input port of the optical multi-dimensional controller is connected with a two-way digital code source, the radio frequency input port of the optical multi-dimensional controller is connected with the single-frequency oscillation signal of the photoelectric oscillator loop, the digital signal sent by the two-way digital code source and the single-frequency oscillation signal of the photoelectric oscillator loop are used for regulating and multiplexing the frequency, the amplitude, the phase and the polarization of the laser sent by the laser source through the optical multi-dimensional controller, and then are divided into two signals by the optical coupler, one output signal of the optical coupler is connected with the input of the electric coupler after sequentially passing through the long optical fiber, the photoelectric detector, the amplifier and the filter, one output signal of the electric coupler is connected with the radio frequency input port of the optical multi-dimensional controller to form a closed photoelectric oscillator, namely OEO; the other path of output signals of the optical coupler are input into the balance detector through the polarization beam splitter to obtain radar communication integrated signals, a schematic diagram of spectrum transformation in the signal generation process is shown in fig. 3, the radar communication integrated signals are transmitted through the transmitting antenna, the receiving antenna receives the radar communication integrated signals, the radar communication integrated signals and the other path of output signals of the electric coupler in the photoelectric oscillator are transmitted to the orthogonal frequency mixer together, the frequency-mixed signals are transmitted to the digital signal processing module, and the digital signal processing module processes and demodulates the frequency-mixed signals to obtain distance information and communication information of a radar, so that radar communication integration is achieved.

In the above microwave photonic radar communication integrated system, the optical multi-dimensional controller has a specific structure as shown in fig. 2, and includes a 90-degree bridge and a dual-polarization dual-parallel modulator, a single-frequency oscillation signal of the optoelectronic oscillator loop is connected to the 90-degree bridge, two output signals of the 90-degree bridge are respectively loaded on two parallel mach-zehnder modulators (MZM) in the X-polarization direction, two paths of digital code sources are loaded on the two parallel mach-zehnder modulators in the Y-polarization direction, and two paths of light in the X-polarization direction and two paths of light in the Y-polarization direction are combined into one path by a polarization beam combiner and are used as the output of the optical multi-dimensional controller.

The invention provides a microwave photon radar communication integration method, which comprises the following steps:

(1) determining the center frequency of a filter in the photoelectric oscillator according to the working frequency band of radar communication integration; the radio frequency signal in the photoelectric oscillator passes through a 90-degree bridge to drive a double-parallel modulator which works in a single-sideband modulation mode in the X polarization direction to generate a single-sideband spectrum E in the X polarization direction_xThe single side band spectrum E_xThe frequency interval between the optical carrier and the radio frequency modulation sideband in the medium is the oscillation frequency omega of the photoelectric oscillator_e；

(2) Setting bits of communication information to c_IAnd c_QDesigning a radar communication integrated signal: namely, two paths of bipolar coded pulse compression signals r are adopted_I(t) and r_Q(t) bipolar coding length M and N, bipolar coding symbol period τ, communication information bit c to be set_IAnd c_QModulated on a pulse-compressed signal r_I(t) and r_Q(t) obtaining two paths of radar communication integrated signals rc on the overall polarity_I(t) and rc_Q(t)；

(3) Rc according to step (2)_I(t) and rc_Q(t) driving a dual-parallel modulator operating in a suppressed carrier modulation mode in the Y polarization direction to produce a baseband spectrum E in the Y polarization direction_y；

(4) Using an optical coupler to input a part of signals of the optical multi-dimensional modulator into a polarization beam splitter, so that two output signals of the polarization beam splitter are respectively E_x+E_yAnd E_x-E_yThe two output signals are subjected to independent beat frequency subtraction in a balanced detector to generate a radio frequency radar communication integrated signal E without carrier leakage and image frequency interference_xE_y ^*The radar communication integrated signal E_xE_y ^*Transmitting through an antenna;

(5) radar communication integrated signal E of step (4)_xE_y ^*After being received by an antenna, the two signals are subjected to orthogonal frequency mixing and analog-to-digital conversion, and then pulse compression is carried out on the two signals in a digital signal processing module to obtain communication information and two paths of radar echo delay information delta tau_IAnd Δ τ_QThe digital signal processing module performs data fusion when the delta tau is equal to the delta tau_I+i·Mτ＝△τ_QWhen + j.Ntau (i and j are any positive integers) is satisfied, the real radar echo delay delta tau is obtained, and the microwave photon radar communication integration is realized.

The microwave photon radar communication integrated method can realize the radar and communication performances as follows: maximum detection distanceCommunication capacityDistance resolutionThe values of M, N and tau can be flexibly changed for performance optimization, so as to better meet the requirements on radar and communication performance in different application scenarios.

The following is a more detailed description of specific embodiments with reference to the drawings.

The invention provides a microwave photon radar communication integrated system, wherein each part is realized as follows:

the response rates of the 90-degree electric bridge, the dual-polarization dual-parallel modulator, the balance detector, the amplifier, the electric coupler, the photoelectric detector and the IQ mixer are greater than the working frequency of the target integrated signal;

the central frequency of the filter is equal to the working frequency of the target integrated signal;

the code rate of the digital code source is larger than the bandwidth of the target integrated signal;

the dual-polarization dual-parallel modulator is biased to be a single-sideband modulation working point in the X direction and biased to be a carrier suppression modulation working point in the Y direction.

In one embodiment of the present invention, the quadrature modulator used is manufactured by Sichuan Hengwei, Inc. under the product number HWIQ 60265-18; the used electric coupler is manufactured by A-INFO company, and the product model is GF-T8-10-26.5; the dual polarization dual parallel modulator used was manufactured by Fuji corporation under the product number FTM 7977.

An embodiment of the method of the invention is described below:

in this embodiment, taking a radar communication integrated system operating at 24GHz frequency and having a bandwidth of 2GHz as an example, where M is 11 and N is 13, an OEO-based microwave photonic radar communication integrated system device is implemented, and experimental verification is performed. The phase noise of the carrier frequency generated in OEO reaches-123 dBc/Hz at 10kHz frequency offset as shown in fig. 4, demonstrating that the generated integrated signal has less phase jitter. The two paths of signals are respectively subjected to pulse compression demodulation at the receiving end, the signals are changed, and a one-dimensional distance image is shown in fig. 5(a) (b), and a one-dimensional distance image after data fusion is shown in fig. 5(c), so that the maximum detection range is greatly expanded under the condition of unchanged resolution, and the problem of distance ambiguity caused by high-speed communication is solved. Meanwhile, a communication capacity of 335.6Mbps was obtained, and a curve (EVM) of the error vector magnitude with the received power was shown in fig. 6.