Radar interference self-decoupling communication method based on Rydberg atomic heterodyne technology

Abstract

The invention relates to the technical field of quantum communication, in particular to a radar interference self-decoupling communication method based on the Rydberg atomic heterodyne technology, which comprises the following steps: establishing a theoretical model of a detection electric field based on the Rydberg atomic heterodyne technology to obtain a change relation of the light intensity of detection light at a receiver along with time; establishing a theoretical model of a detection light signal at the Rydberg heterodyne receiver under the combined action of communication and a radar transmitter according to the change relation of the light intensity of the detection light at the receiver along with time, and obtaining a corresponding relation between a communication modulation symbol and the light intensity of the detection light at the receiver; and establishing a network-detector composite adaptive decoupling model, and automatically switching a decoupling mode according to the monitored radar signal power to perform radar signal decoupling. According to the invention, accurate demodulation of communication signals is realized under the condition of radar interference of different powers, and the demodulation result is not limited by channel state estimation accuracy.

Description

Technical Field

[0001] The present invention relates to the field of quantum communication technology, and in particular to a radar interference self-decoupling communication method based on Rydberg atom heterodyne technology. Background Art

[0002] In communication applications, Rydberg atoms have replaced traditional antennas with their subwavelength size, wide operating frequency range, and excellent self-calibration performance. At present, receivers using Rydberg atom heterodyne technology have been verified to achieve excellent performance in wireless communications through various modulation schemes. In the context of communication and radar integration, S-band (2-4GHz) communication and radar spectrum sharing has become inevitable. When two systems occupy the same spectrum to transmit signals, the interference of radar signals will damage the quality of communication transmission.

[0003] How to accurately extract transmission information from signals containing radar interference is the core issue of communication applications based on Rydberg atom heterodyne technology in the context of spectrum sharing: the detection process of communication signals is converted into a multi-classification problem through the deep neural network method. This method does not require channel estimation and shows good performance under complex channel conditions, but in the case of high-power radar interference, the bit error rate will be significantly improved; through traditional signal detectors, by estimating the information of the radar interference signal and removing it from the received signal, this method has achieved good results in high-power radar interference estimation and elimination, but this method is highly dependent on channel state information, and the detection accuracy is affected by channel estimation. Summary of the invention

[0004] In view of the above-mentioned deficiencies in the prior art, the present invention provides a radar interference self-decoupling communication method based on Rydberg atomic heterodyne technology to ensure accurate demodulation of communication signals under conditions of radar interference of different powers, and the demodulation results are not limited by the accuracy of channel state estimation.

[0005] In order to achieve the above-mentioned object of the invention, the technical solution adopted by the present invention is:

[0006] A radar interference self-decoupling communication method based on Rydberg atomic heterodyne technology comprises the following steps:

[0007] A theoretical model for detecting electric fields based on Rydberg heterodyne technology was established to obtain the relationship between the intensity of the detection light at the receiver and time.

[0008] According to the relationship between the intensity of the detection light at the receiver and time, a theoretical model of the detection light signal at the Rydberg heterodyne receiver under the joint action of communication and radar transmitters is established, and the corresponding relationship between the communication modulation symbol and the intensity of the detection light at the receiver is obtained;

[0009] A network-detector composite adaptive decoupling model is established, and the decoupling mode is automatically switched according to the monitored radar signal power to perform radar signal decoupling.

[0010] Preferably, establishing a theoretical model for detecting electric field based on Rydberg heterodyne technology includes:

[0011] The detection laser and the coupling laser are transmitted in opposite directions along overlapping optical paths through the atomic gas chamber to stimulate the Rydberg atoms to transition to the Rydberg energy level;

[0012] Applying a radio frequency electric field stimulates the Rydberg atomic transition, causing the EIT peak to produce AT splitting;

[0013] The radio frequency electric field is used as the local oscillator field LO, and another weak radio frequency electric field that is slightly detuned from the local oscillator field LO is applied as the signal field SIG. The sum of the electric fields of the local oscillator field LO and the signal field SIG is used as the total electric field of the atomic gas chamber to determine the total electric field strength in the gas chamber.

[0014] Preferably, the total electric field strength in the air chamber is:

[0015]

[0016] Among them, |E sum | is the total electric field strength in the air chamber, E 1 is the electric field of the local oscillator field LO, E 2 is the electric field of the signal field SIG, E LO is the amplitude of the local oscillator field LO, E SIG is the amplitude of the signal field SIG, Δω is the frequency difference between the local oscillator field LO and the signal field SIG, t is the time, is the relative phase between the local oscillator field LO and the signal field SIG.

[0017] Preferably, the relationship between the intensity of the detection light at the receiver and time is:

[0018] I(t)∝|E sum |≈E LO +E SIG cos(Δωt+Δφ)

[0019] Where I(t) is the intensity of the detection light at the receiver, |E sum | is the total electric field strength in the air chamber, ELO is the amplitude of the local oscillator field LO, and E SIG is the amplitude of the signal field SIG, Δω is the frequency difference between the local oscillator field LO and the signal field SIG, t is the time, is the relative phase between the local oscillator field LO and the signal field SIG.

[0020] Preferably, according to the relationship between the intensity of the detection light at the receiver and time, a theoretical model of the detection light signal at the Rydberg heterodyne receiver under the joint action of the communication and radar transmitters is established to obtain the corresponding relationship between the communication modulation symbol and the intensity of the detection light at the receiver, including:

[0021] The transmitter of Rydberg heterodyne technology is composed of local oscillator field and signal field microwave source, and the information transmission of communication transmitter and radar transmitter is carried out by modulating signal field;

[0022] The communication transmitter is digitally modulated using a frequency shift keying modulation method to transmit symbols, and a communication transmitter model is established;

[0023] Considering the interference of pulse linear frequency modulation radar signal, the radar transmitter model is established;

[0024] According to the communication transmitter model and the radar transmitter model, a theoretical model of the detection light signal at the Rydberg heterodyne receiver under the joint action of the communication and radar transmitters is established, and the corresponding relationship between the communication modulation symbol and the detection light intensity at the receiver is obtained.

[0025] Preferably, the correspondence between the communication modulation symbol and the intensity of the detection light at the receiver is:

[0026] I(t)∝|E sum |=|E com +E radar +E n |

[0027] ≈(E LO1 +E LO2 )+(E SIG1 cos(2πf k t+φ 1 )+E SIG2 cos(2πf IF2 t+πut 2 +φ 2 ))+E noise (t)

[0028] Where I(t) is the intensity of the detection light at the receiver, |E sum | is the total electric field strength in the air chamber, E com is the total electric field of the communication transmitter in the air chamber, E radar is the total electric field of the radar transmitter in the air chamber, E n is the electric field noise in the air chamber, E LO1 is the bias of the communication signal, E LO2 is the bias of the radar signal, E SIG1 is the amplitude of the communication signal, f k is the communication signal frequency corresponding to the kth symbol, t is the time, φ1 is the phase of the communication signal, E SIG2 is the amplitude of the radar signal, f IF2 is the intermediate frequency of the radar signal, u is the modulation frequency, φ 2 is the phase of the radar signal, E noise is additive white Gaussian noise.

[0029] Preferably, a network-detector composite adaptive decoupling model is established, and a decoupling mode is automatically switched according to the monitored radar signal power to perform radar signal decoupling, including:

[0030] Establish a network-detector composite adaptive decoupling model;

[0031] Monitor radar signal power and calculate SIR value of radar signal;

[0032] When the SIR value of the radar signal is greater than the set threshold, the network-detector composite adaptive decoupling model is switched to the weak radar interference decoupling mode at high SIR;

[0033] When the SIR value of the radar signal is less than or equal to the set threshold, the network-detector composite adaptive decoupling model is switched to the strong radar interference decoupling mode at low SIR.

[0034] Preferably, the weak radar interference decoupling mode at high SIR includes:

[0035] A deep learning network combining convolutional neural network and long short-term memory network is used as the detector of communication signals. The time-frequency characteristics of the receiver's time domain signal are extracted using short-time Fourier transform to obtain a time-frequency graph, which is then input into the deep learning network to extract the feature sequence.

[0036] The feature sequence is input into the long short-term memory layer to extract the timing features of the communication signal, and the timing features of the communication signal are mapped to multiple modulation categories to obtain the probability distribution of the frequency deviation of the communication signal.

[0037] Preferably, the strong radar interference decoupling mode at low SIR includes:

[0038] Initialize radar signal parameters and filter gain matrix;

[0039] Calculate error signal and gain vector;

[0040] The radar signal parameters and filter gain matrix are updated according to the error signal and the gain vector until the parameter estimation converges.

[0041] Preferably, establishing a network-detector composite adaptive decoupling model includes:

[0042] Collect the detection signals of the Rydberg heterodyne receiver under various radar interference powers and communication frequency modulation symbols, and establish a small sample model data set;

[0043] Data cleaning and data enhancement processing for small sample model datasets;

[0044] The processed small sample model dataset is used to optimize the network-detector composite adaptive decoupling model.

[0045] The present invention has the following beneficial effects:

[0046] 1. The present invention establishes a Rydberg heterodyne receiver signal model for communication applications under the background of radar interference, constructs a multi-parameter mapping function of the integrated communication signal, and provides a measurement and tracing method for large-scale radar power decoupling.

[0047] 2. The present invention establishes a network-traditional detector composite adaptive decoupling model, regularly monitors the channel and completes automatic mode switching, solving the problem that communication information cannot be detected in real time and with high performance in scenarios of unknown power radar interference.

[0048] 3. The present invention establishes a model database, provides feedback on the decoupling error under changing radar power, and completes the dynamic adjustment of the internal parameters of the decoupling model, thus having a stronger ability to adapt to environmental changes. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] Figure 1 A schematic diagram of a radar interference self-decoupling communication method based on Rydberg atomic heterodyne technology;

[0050] Figure 2 It is a schematic diagram of the integrated communication system based on Rydberg heterodyne technology;

[0051] Figure 3 Schematic diagram of radar interference self-decoupling process based on Rydberg heterodyne technology. DETAILED DESCRIPTION

[0052] The specific implementation modes of the present invention are described below so that those skilled in the art can understand the present invention. However, it should be clear that the present invention is not limited to the scope of the specific implementation modes. For those of ordinary skill in the art, as long as various changes are within the spirit and scope of the present invention as defined and determined by the attached claims, these changes are obvious, and all inventions and creations utilizing the concept of the present invention are protected.

[0053] The present invention aims at the problem of accurate demodulation of communication information under the background of integrated communication radar, and provides a radar interference self-decoupling communication method and system based on Rydberg atomic heterodyne technology. Based on the technical principle of Rydberg atomic heterodyne detection of microwave electric field, the signal at the Rydberg receiver under the background of radar interference is analyzed and processed. According to the situation of different power radar interference, the corresponding signal decoupling scheme is designed, and real-time and automatic mode switching can be realized. Thus, high-performance communication transmission of Rydberg atomic heterodyne technology under wide range of power radar interference is realized.

[0054] like Figure 1 As shown, a radar interference self-decoupling communication method based on Rydberg atomic heterodyne technology provided by an embodiment of the present invention includes the following steps S1 to S3:

[0055] S1. Establish a theoretical model for detecting electric fields based on Rydberg heterodyne technology, and obtain the relationship between the intensity of the detection light at the receiver and time.

[0056] In an optional embodiment of the present invention, the theoretical model for detecting electric field based on Rydberg heterodyne technology is established in this embodiment, including:

[0057] The detection laser and the coupling laser are transmitted in opposite directions along overlapping optical paths through the atomic gas chamber to stimulate the Rydberg atoms to transition to the Rydberg energy level;

[0058] Applying a radio frequency electric field stimulates the Rydberg atomic transition, causing the EIT peak to produce AT splitting;

[0059] The radio frequency electric field is used as the local oscillator field LO, and another weak radio frequency electric field that is slightly detuned from the local oscillator field LO is applied as the signal field SIG. The sum of the electric fields of the local oscillator field LO and the signal field SIG is used as the total electric field of the atomic gas chamber to determine the total electric field strength in the gas chamber.

[0060] like Figure 2 As shown, in this embodiment, the detection laser and the coupling laser are transmitted in the opposite direction along the overlapping optical path through the atomic gas chamber to excite the Rydberg atoms to transition to the Rydberg energy level. In one embodiment, the Rydberg atoms are selected as 133Cs atoms, and the detection laser is tuned to 852nm wavelength to convert the Cs atoms from the ground state 6S 1 / 2 Excited to the intermediate state 6P 3 / 2 ; Tune the coupled laser to 509nm wavelength to excite the Cs atoms to the Rydberg state 62D 5 / 2 , the transmittance of the probe laser through the atomic gas chamber increases, and an EIT signal appears in the photodetector. The power of the probe laser is 52μW, and the power of the coupled laser is 30mW.

[0061] At this time, applying a 2.911 GHz radio frequency electric field will cause Cs atoms to move from 62D 5 / 2 Jump to 63P 3 / 2, the EIT peak produces AT splitting. The RF electric field resonating with the Rydberg transition is used as the local oscillator field LO, and another weak RF electric field slightly detuned from LO is applied as the signal field SIG. At this time, the total electric field of the atomic gas chamber is the sum of the LO and SIG fields. Assuming the LO field is E 1 =E LO cos(ω LO t+φ LO ), SIG field is E 2 =E SIG cos(ω SIG t+φ SIG ), when the difference Δω between the two frequencies is much smaller than their average frequency When , the total electric field intensity in the air chamber can be expressed as:

[0062]

[0063] Among them, |E sum | is the total electric field strength in the air chamber, E 1 is the electric field of the local oscillator field LO, E 2 is the electric field of the signal field SIG, E LO is the amplitude of the local oscillator field LO, E SIG is the amplitude of the signal field SIG, Δσ is the frequency difference between the local oscillator field LO and the signal field SIG, t is the time, It is the relative phase between the local oscillator field LO and the signal field SIG.

[0064] Using the magnetic susceptibility χ of the detection light medium, the transition coefficient T of the detection light passing through the vapor pool can be obtained. probe , further calculate the detection light intensity I detected by the photodetector:

[0065]

[0066] Among them, I 0 is the intensity of the detection light before entering the atomic gas cell, L is the length of the gas cell, and λ p is the wavelength of the detection light. In the resonance field, the detection light intensity I is proportional to the electric field strength. Since the SIG field strength is much smaller than the LO field strength (E SIG <<E LO ), the change of the detection light intensity over time can be expressed as follows:

[0067] I(t)∝|E sum |≈≈E LO +E SIG cos(Δωt+△φ)

[0068] Where I(t) is the intensity of the detection light at the receiver, |E sun | is the total electric field strength in the air chamber, ELO is the amplitude of the local oscillator field LO, and ESIG is the amplitude of the signal field SIG, Δω is the frequency difference between the local oscillator field LO and the signal field SIG, t is the time, It is the relative phase between the local oscillator field LO and the signal field SIG.

[0069] It can be concluded that under the combined effect of the LO and SIG fields, an intermediate frequency signal will be observed on the Rydberg heterodyne receiver. The frequency of the intermediate frequency signal corresponds to the frequency difference f between the local oscillator field LO and the signal field SIG. IF =Δω / 2π, the phase corresponds to the relative phase Δφ between the local oscillator field LO and the signal field SIG.

[0070] S2. According to the relationship between the intensity of the detection light at the receiver and time, a theoretical model of the detection light signal at the Rydberg heterodyne receiver under the joint action of the communication and radar transmitters is established to obtain the corresponding relationship between the communication modulation symbol and the intensity of the detection light at the receiver;

[0071] In an optional embodiment of the present invention, this embodiment establishes a theoretical model of the detection light signal at the Rydberg heterodyne receiver under the joint action of the communication and radar transmitters according to the relationship between the change of the detection light intensity at the receiver with time, and obtains the corresponding relationship between the communication modulation symbol and the detection light intensity at the receiver, including:

[0072] The transmitter of Rydberg heterodyne technology is composed of local oscillator field and signal field microwave source, and the information transmission of communication transmitter and radar transmitter is carried out by modulating signal field;

[0073] The communication transmitter is digitally modulated using a frequency shift keying modulation method to transmit symbols, and a communication transmitter model is established;

[0074] Considering the interference of pulse linear frequency modulation radar signal, the radar transmitter model is established;

[0075] According to the communication transmitter model and the radar transmitter model, a theoretical model of the detection light signal at the Rydberg heterodyne receiver under the joint action of the communication and radar transmitters is established, and the corresponding relationship between the communication modulation symbol and the detection light intensity at the receiver is obtained.

[0076] The transmitter of the Rydberg heterodyne technology is composed of a local oscillator field and a signal field microwave source. Both the communication and radar transmitters transmit information by modulating the signal field. In the embodiment, narrowband radar interference in a single-input single-output communication system is considered. For the communication transmitter, a frequency shift keying (FSK) modulation scheme is adopted, and the transmitted symbol is digitally modulated to represent K possibilities. The kth possible passband equivalent signal can be expressed as:

[0077] |e Com | k ≈E LO1 +E SIG1cos(2πf k t+φ 1 ), 0≤t≤T com

[0078] Among them, |E com | k is the total electric field strength of the communication transmitter in the air chamber, E LO1 is the bias of the communication signal, E SIG1 is the amplitude of the communication signal, f k is the communication signal frequency corresponding to the kth symbol, t is the time, φ 1 is the phase of the communication signal, T com is the communication duration. The communication signal offset E LO1 , amplitude E SIG1 and phase φ 1 are all constant. The communication signal frequency corresponding to the kth symbol can be expressed as f k =f IF1 +(k-4)f Offset , k = 1, 2, ..., K, where f IF1 is the intermediate frequency of the communication signal, f Offset The frequency offset value for each symbol.

[0079] For the radar transmitter, the interference of pulse linear frequency modulation (LFM) radar signal is mainly considered, and its model can be written in the form of a sine function as follows:

[0080] |E radar |≈E LO2 +E SIG2 cos(2πf IF2 t+πut 2 +φ 2 ),0≤t≤T radar

[0081] Among them, |E radar | is the total electric field strength of the radar transmitter in the air chamber, E LO2 is the bias of the radar signal, E SIG2 is the amplitude of the radar signal, f IF2 is the intermediate frequency of the radar signal, t is the time, u is the modulation frequency, φ 2 is the phase of the radar signal, T radar is the duration of the pulse. The offset E of the radar signal LO2 is constant, the amplitude E SIG2 and phase φ 2 is unknown, u is the modulation frequency, defined as Where B is the signal bandwidth, T radaris the duration of the pulse. Under the combined effect of the communication and radar transmitters, the signal at the Rydberg heterodyne receiver can be approximately expressed as:

[0082] I(t)∝|E sum |=|E om +E radar +E n |

[0083] ≈(E LO1 +E LO2 )+(E SIG1 cos(2πf k t+φ 1 )+E SIG2 cos(2πf IF2 t+πut 2 +φ 2 ))+E noise (t)

[0084] Where I(t) is the intensity of the detection light at the receiver, |E sum | is the total electric field strength in the air chamber, E com is the total electric field of the communication transmitter in the air chamber, E radar is the total electric field of the radar transmitter in the air chamber, E n is the electric field noise in the air chamber, E LO1 is the bias of the communication signal, E LO2 is the bias of the radar signal, E SIG1 is the amplitude of the communication signal, f k is the communication signal frequency corresponding to the kth symbol, t is the time, φ 1 is the phase of the communication signal, E SIG2 is the amplitude of the radar signal, f IF2 is the intermediate frequency of the radar signal, u is the modulation frequency, φ 2 is the phase of the radar signal, E noise (t) means the mean is zero and the variance is σ 2 Additive white Gaussian noise.

[0085] It can be concluded that the signal at the Rydberg heterodyne receiver can be approximately modeled as a combination of two cosine signals of different frequencies with a fixed offset and Gaussian noise.

[0086] S3. Establish a network-detector composite adaptive decoupling model, and automatically switch the decoupling mode to perform radar signal decoupling according to the monitored radar signal power.

[0087] In an optional embodiment of the present invention, this embodiment establishes a network-detector composite adaptive decoupling model, and automatically switches the decoupling mode according to the monitored radar signal power to perform radar signal decoupling, including:

[0088] Establish a network-detector composite adaptive decoupling model;

[0089] Monitor radar signal power and calculate SIR value of radar signal;

[0090] When the SIR value of the radar signal is greater than the set threshold, the network-detector composite adaptive decoupling model is switched to the weak radar interference decoupling mode at high SIR;

[0091] When the SIR value of the radar signal is less than or equal to the set threshold, the network-detector composite adaptive decoupling model is switched to the strong radar interference decoupling mode at low SIR.

[0092] Among them, the weak radar interference decoupling modes at high SIR include:

[0093] A deep learning network combining convolutional neural network and long short-term memory network is used as the detector of communication signals. The time-frequency characteristics of the receiver's time domain signal are extracted using short-time Fourier transform to obtain a time-frequency graph, which is then input into the deep learning network to extract the feature sequence.

[0094] The feature sequence is input into the long short-term memory layer to extract the timing features of the communication signal, and the timing features of the communication signal are mapped to multiple modulation categories to obtain the probability distribution of the frequency deviation of the communication signal.

[0095] Among them, the strong radar interference decoupling mode at low SIR includes:

[0096] Initialize radar signal parameters and filter gain matrix;

[0097] Calculate error signal and gain vector;

[0098] The radar signal parameters and filter gain matrix are updated according to the error signal and the gain vector until the parameter estimation converges.

[0099] In one embodiment, a radar transmitter is used to generate a radar signal with time-varying power, while a communication transmitter is used to transmit a binary-coded image signal. Because the parameters of the radar system change slowly, the amplitude of the radar signal can be roughly estimated by periodically monitoring the channel during the transmission of the communication signal. SIG2 , calculate the SIR value as the judgment condition for the classification processing of the adaptive decoupling model to switch the decoupling mode in real time and automatically. The SIR calculation formula is as follows:

[0100]

[0101] Among them, E SIG1 is the amplitude of the communication signal, E SIG2The amplitude of the radar signal is set to 15 dB, and the threshold for judging high and low SIR is set to 15 dB. Images are transmitted at different bit rates and the pixel error rate is calculated to achieve quantitative evaluation of the performance of the composite decoupling model.

[0102] like Figure 3 As shown, in order to achieve high-performance elimination of wide-range power radar interference signals, this embodiment establishes a network-traditional detector composite adaptive decoupling model. The solver modeling is divided into the following two cases: weak radar interference at high SIR and strong radar interference at low SIR.

[0103] In response to weak radar interference at high SIR, the receiver signal is dominated by the communication signal. This embodiment designs a deep learning network that combines a convolutional neural network and a long short-term memory network as a detector of the communication signal. The short-time Fourier transform is used to extract the time-frequency characteristics of the receiver time domain signal I(t) to obtain the time-frequency graph S(t, f), which is input into the deep learning network. First, it passes through a convolutional neural network layer consisting of convolution layer 1-pooling layer-convolution layer to extract low- and high-level time-frequency features and reduce the signal data dimension. The formula is:

[0104]

[0105] Wherein, σ(·) is an activation function, and the Rectified Linear Unit function is used in this embodiment. 1 (t, f) is the feature sequence output by convolutional layer 1, W 1 (i, j) and b 1 is the convolution kernel and bias term of convolution layer 1; h p1 (t, f) is the feature sequence output by the pooling layer; h 2 (t, f) is the feature sequence output by convolutional layer 2, W 2 (i, j) and b 2 are the convolution kernel and bias term of convolution layer 2. In this embodiment, the convolution kernel size of the two convolution layers is 3×3, and the maximum pooling is 2×2.

[0106] The feature sequence h output by the convolutional layer 2 (t, f) is input to the long short-term memory layer to capture the timing characteristics of the signal and is mapped to K modulation categories through the fully connected layer. The formula is:

[0107]

[0108] Among them, h T is the output of the last time step of LSTM, z 1 is the output of the fully connected layer 1, W 3 and b 3 are the weights and biases of the fully connected layer 1; z 2is the output of the fully connected layer 2, W 4 and b 4 are the weights and biases of the fully connected layer 2. The high-dimensional features are compressed into the score space of K categories. Finally, the output of the fully connected layer is converted into K-category frequency deviation f through the Softmax activation function. k The probability distribution of the signal I(t) belongs to the kth frequency deviation. The calculation formula is:

[0109]

[0110] Among them, z 2，k is the score of the kth class. During the network training process, the best performance of the neural network is obtained by finding the optimal value of the network weight parameter. The cross entropy loss function L is used to evaluate the classification performance of the model:

[0111]

[0112] Among them I i is the actual label of sample i, is the predicted value of the model, and N is the number of time windows.

[0113] Then, the Adam optimizer is used to update the network parameters, and the optimization goal is to minimize the loss function:

[0114]

[0115] where ω t is the current network weight, and η is the learning rate.

[0116] For strong radar interference at low SIR, E SIG1 <<E SIG2 When the communication signal is almost submerged by the radar interference signal, the performance of the network method is greatly reduced. In this case, this embodiment uses the self-recursive least squares algorithm in the adaptive filtering method to calculate the parameters of the radar interference signal and remove it from the original signal. The self-recursive least squares filter minimizes the prediction error by updating the weight vector w[n] of the filter. The filter output and the radar signal prediction value are expressed as Where x[n] is the input signal vector. First, set the initial value of the filter weight vector w[0] and the initial value of the filter gain matrix P[0] = I. Then calculate the error signal e[n] and the gain vector k[n]:

[0117]

[0118]

[0119] Where I[n] is the receiver signal sample, E LO1and E LO2 are the biases of communication and radar signals respectively, is the predicted value of the radar interference signal, x[n] is the input signal vector, P[n] is the inverse covariance matrix, and λ is the forgetting factor, which ranges from 0 to 1.

[0120] According to the results of dynamic calculation, the filter weight vector w[n] and the gain matrix P[n] are updated. The update process is expressed as:

[0121] w[n]=w[n-1]+k[n]e[n]

[0122]

[0123] Repeat this step until the parameter estimation converges, and the estimated radar signal can be output through the filter.

[0124] In an optional embodiment of the present invention, this embodiment establishes a small sample model data set and iterates the internal parameters of the model to improve the solution performance.

[0125] This embodiment establishes a network-detector composite adaptive decoupling model including:

[0126] Collect the detection signals of the Rydberg heterodyne receiver under various radar interference powers and communication frequency modulation symbols, and establish a small sample model data set;

[0127] Data cleaning and data enhancement processing for small sample model datasets;

[0128] The processed small sample model dataset is used to optimize the network-detector composite adaptive decoupling model.

[0129] The detection signals of the Rydberg heterodyne receiver under various radar interference powers and communication frequency modulation symbols are collected to establish a small sample model data set {k, I(t)}, where k is the modulation frequency deviation category label of the communication signal and sample I(t) contains radar interference and Gaussian noise. In order to improve the generalization ability of the model, enhance data diversity and reduce the impact of noise, the small sample data set is preprocessed.

[0130] First, we use statistical methods based on mean and standard deviation to identify and remove possible outliers caused by vibration, electromagnetic interference, etc. The condition for determining outliers is: |x-μ|>3σ. Then we use a bandpass filter to remove laser noise, optical device thermal noise, shot noise, etc. from the data. The process can be expressed as I band (f) = I(f)H(f), where H(f) is the transfer function of the filter. This can reduce the interference of irrelevant information on the model and improve the quality of the model data.

[0131] Next, data enhancement is performed to convert the sample I(t) into I(t+Δt) with a slight time offset to simulate the receiver signal under different time offsets, thereby increasing the diversity of samples. For small sample data sets, the data may be sparse and incomplete. 1 (t), I 2 (t) Perform weighted average synthesis of new samples I new (t), the process can be expressed as:

[0132] I new (t) = αI 1 (t)+(1-α)I 2 (t)

[0133] Among them, α∈[0, 1] is a weighting function. By taking different values ​​of α, richer signal variants can be generated, which can improve the robustness and generalization ability of the model.

[0134] The present invention is described with reference to flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to embodiments of the present invention. It should be understood that each process and / or block in the flowchart and / or block diagram, as well as the combination of processes and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0135] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0136] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 A step that specifies a function in one or more boxes.

[0137] The present invention uses specific embodiments to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the method of the present invention and its core idea. At the same time, for those skilled in the art, according to the idea of ​​the present invention, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as a limitation on the present invention.

[0138] Those skilled in the art will appreciate that the embodiments described herein are intended to help readers understand the principles of the present invention, and should be understood that the protection scope of the present invention is not limited to such specific statements and embodiments. Those skilled in the art can make various other specific variations and combinations that do not deviate from the essence of the present invention based on the technical revelations disclosed by the present invention, and these variations and combinations are still within the protection scope of the present invention.

Claims

1. A radar interference self-decoupling communication method based on Rydberg atom heterodyne technology, characterized in that: The following steps are involved: A theoretical model for detecting electric fields based on Rydberg heterodyne technology was established to obtain the relationship between the intensity of the detection light at the receiver and time. According to the relationship between the intensity of the detection light at the receiver and time, a theoretical model of the detection light signal at the Rydberg heterodyne receiver under the joint action of communication and radar transmitters is established, and the corresponding relationship between the communication modulation symbol and the intensity of the detection light at the receiver is obtained; A network-detector composite adaptive decoupling model is established, and the decoupling mode is automatically switched according to the monitored radar signal power to perform radar signal decoupling.

2. The radar interference self-decoupling communication method based on Rydberg atom heterodyne technology according to claim 1, characterized in that: The theoretical model for detecting electric field based on Rydberg heterodyne technology includes: The detection laser and the coupling laser are transmitted in opposite directions along overlapping optical paths through the atomic gas chamber to excite the Rydberg atoms to transition to the Rydberg energy level; Applying a radio frequency electric field stimulates the Rydberg atomic transition, causing the EIT peak to produce AT splitting; The radio frequency electric field is used as the local oscillator field LO, and another weak radio frequency electric field that is slightly detuned from the local oscillator field LO is applied as the signal field SIG. The sum of the electric fields of the local oscillator field LO and the signal field SIG is used as the total electric field of the atomic gas chamber to determine the total electric field strength in the gas chamber.

3. The radar interference self-decoupling communication method based on Rydberg atomic heterodyne technology according to claim 2 is characterized in that: The total electric field strength in the air chamber is: Among them, |E sum | is the total electric field strength in the air chamber, E1 is the electric field of the local oscillator field LO, E2 is the electric field of the signal field SIG, and E LO is the amplitude of the local oscillator field LO, E SIG is the amplitude of the signal field SIG, Δω is the frequency difference between the local oscillator field LO and the signal field SIG, t is the time, is the relative phase between the local oscillator field LO and the signal field SIG.

4. The radar interference self-decoupling communication method based on Rydberg atom heterodyne technology according to claim 1, characterized in that: The relationship between the intensity of the detection light at the receiver and time is: I(t)∝|E sum |≈E LO +E SIG cos(Δωt+Δφ) Where I(t) is the intensity of the detection light at the receiver, |E sum | is the total electric field strength in the air chamber, E LO is the amplitude of the local oscillator field LO, E SIG is the amplitude of the signal field SIG, Δω is the frequency difference between the local oscillator field LO and the signal field SIG, t is the time, and Δφ is the relative phase between the local oscillator field LO and the signal field SIG.

5. The radar interference self-decoupling communication method based on Rydberg atomic heterodyne technology according to claim 1, characterized in that: According to the relationship between the intensity of the detection light at the receiver and time, a theoretical model of the detection light signal at the Rydberg heterodyne receiver under the joint action of communication and radar transmitters is established, and the corresponding relationship between the communication modulation symbol and the intensity of the detection light at the receiver is obtained, including: The transmitter of Rydberg heterodyne technology is composed of local oscillator field and signal field microwave source, and the information transmission of communication transmitter and radar transmitter is carried out by modulating signal field; The communication transmitter is digitally modulated using a frequency shift keying modulation method to transmit symbols, and a communication transmitter model is established; Considering the interference of pulse linear frequency modulation radar signal, the radar transmitter model is established; According to the communication transmitter model and the radar transmitter model, a theoretical model of the detection light signal at the Rydberg heterodyne receiver under the joint action of the communication and radar transmitters is established, and the corresponding relationship between the communication modulation symbol and the detection light intensity at the receiver is obtained.

6. The radar interference self-decoupling communication method based on Rydberg atomic heterodyne technology according to claim 5 is characterized in that: The corresponding relationship between the communication modulation symbol and the detection light intensity at the receiver is: I(t)∝|E sum |=|And com +E radar +E n | ≈(E LO1 +E LO2 )+(E SIG1 cos(2πf k t+φ1)+E SIG2 cos(2πf IF2 t+πut 2 +φ2))+E noise (t) Where I(t) is the intensity of the detection light at the receiver, |E sum | is the total electric field strength in the air chamber, E com is the total electric field of the communication transmitter in the air chamber, E radar is the total electric field of the radar transmitter in the air chamber, E n is the electric field noise in the air chamber, E LO1 is the bias of the communication signal, E LO2 is the bias of the radar signal, E SIG1 is the amplitude of the communication signal, f k is the communication signal frequency corresponding to the kth symbol, t is the time, φ1 is the phase of the communication signal, E SIG2 is the amplitude of the radar signal, f IF2 is the intermediate frequency of the radar signal, u is the modulation frequency, φ2 is the phase of the radar signal, E noise is additive white Gaussian noise.

7. The radar interference self-decoupling communication method based on Rydberg atomic heterodyne technology according to claim 1, characterized in that: A network-detector composite adaptive decoupling model is established, and the decoupling mode is automatically switched according to the monitored radar signal power to perform radar signal decoupling, including: Establish a network-detector composite adaptive decoupling model; Monitor radar signal power and calculate SIR value of radar signal; When the SIR value of the radar signal is greater than the set threshold, the network-detector composite adaptive decoupling model is switched to the weak radar interference decoupling mode at high SIR; When the SIR value of the radar signal is less than or equal to the set threshold, the network-detector composite adaptive decoupling model is switched to the strong radar interference decoupling mode at low SIR.

8. The radar interference self-decoupling communication method based on Rydberg atomic heterodyne technology according to claim 7, characterized in that: Weak radar jammer decoupling modes at high SIR include: A deep learning network combining convolutional neural network and long short-term memory network is used as the detector of communication signals. The short-time Fourier transform is used to extract the time-frequency characteristics of the receiver's time domain signal to obtain a time-frequency graph, which is then input into the deep learning network to extract the feature sequence. The feature sequence is input into the long short-term memory layer to extract the timing features of the communication signal, and the timing features of the communication signal are mapped to multiple modulation categories to obtain the probability distribution of the frequency deviation of the communication signal.

9. The radar interference self-decoupling communication method based on Rydberg atom heterodyne technology according to claim 7, characterized in that: Strong radar jammer decoupling modes at low SIR include: Initialize radar signal parameters and filter gain matrix; Calculate error signal and gain vector; The radar signal parameters and filter gain matrix are updated according to the error signal and the gain vector until the parameter estimation converges.

10. The radar interference self-decoupling communication method based on Rydberg atom heterodyne technology according to claim 1, characterized in that: Establishing a network-detector composite adaptive decoupling model includes: Collect the detection signals of the Rydberg heterodyne receiver under various radar interference powers and communication frequency modulation symbols, and establish a small sample model data set; Data cleaning and data enhancement processing for small sample model datasets; The processed small sample model dataset is used to optimize the network-detector composite adaptive decoupling model.

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