Transmitting and receiving method of full-time electronic interference system

Abstract

The invention discloses a full-time electronic interference system transmitting and receiving method which comprises the following steps: S1, a jammer generates an interference signal with the period of N, and the interference signal is transmitted after being subjected to digital-to-analog conversion and up-conversion operation; s2, enabling the reconnaissance receiver to enter a training mode, carrying out down-conversion and analog-to-digital conversion operation on self-interference and reference signals, caching the self-interference and reference signals for the length of 2N, selecting N data, converting the N data into a frequency domain, and carrying out self-interference channel estimation; and S3, enabling the reconnaissance receiver to enter a reconnaissance mode, carrying out down-conversion and analog-to-digital conversion operation on the received and reference signals, caching the received and reference signals by the length of 2N, selecting N data, converting the N data into a frequency domain, reconstructing and cancelling a self-interference signal by using the reference signal and the channel estimation value, and inversely converting the self-interference signal back to a time domain to obtain a target signal. According to the invention, a mode of combining a training mode and a reconnaissance mode is adopted, and the self-interference problem of an interference detection and reception integrated system is solved.

Description

Technical Field

[0001] The present invention relates to a full-time electronic jamming system, in particular to a transceiver method of the full-time electronic jamming system. Background Art

[0002] For core combat platforms such as fighter jets, ships, and armored vehicles, it is crucial to accurately monitor battlefield situational information and possess the ability to transmit and receive electronic jamming and reconnaissance at all times. For example, during combat, advanced fighter jets rely on jammers to monitor enemy electronic signals at all times, providing strong support for operational decision-making. However, when jamming and reconnaissance functions operate simultaneously on the same platform, the high-power jamming signals emitted can cause severe self-interference on the reconnaissance receivers on the same platform, significantly interfering with or even blocking the reconnaissance aircraft's effective detection of target signals, posing a significant challenge to the smooth progress of combat operations. To avoid the self-interference problem of simultaneous transmission and reception, existing solutions often utilize a time-sharing system, but this cannot achieve full-time jamming and reconnaissance of target signals—that is, uninterrupted jamming and reconnaissance. For example, by dividing time into multiple time slots and scheduling reconnaissance and jamming operations in different time slots, jamming or important enemy signal interference or information cannot be detected during jamming time slots, while jamming and attacking the enemy during reconnaissance time slots are incapable of interfering and attacking, potentially posing a threat to the combat platform. Summary of the Invention

[0003] The purpose of the present invention is to overcome the shortcomings of the prior art and provide a full-time electronic jamming system transmission and reception method, which adopts a combination of training mode and reconnaissance mode. In the training mode, the frequency domain estimation of the self-interference channel is performed, and then in the reconnaissance mode, the frequency domain cancellation of the self-interference signal is performed to solve the self-interference problem of the interference detection and reception common platform.

[0004] The object of the present invention is achieved through the following technical solution: a full-time electronic jamming system transmission and reception method, the full-time electronic jamming system includes a jammer and a reconnaissance receiver, the method comprising the following steps:

[0005] S1. The jammer generates an interference signal with a period of N, performs digital-to-analog conversion and up-conversion operations, and then transmits it;

[0006] S2. The reconnaissance receiver enters training mode, down-converts the self-interference and reference signals, performs analog-to-digital conversion, and caches them in a 2N-length buffer. N of these data are then selected and converted to the frequency domain for self-interference channel estimation.

[0007] S3. The reconnaissance receiver enters reconnaissance mode, down-converts the received and reference signals, performs analog-to-digital conversion, and caches them in a 2N-length buffer. N of the data are selected and transformed into the frequency domain. The reference signal and channel estimate are used to reconstruct and cancel the self-interference signal. The receiver then inversely transforms the signal back into the time domain to obtain the target signal.

[0008] The beneficial effects of the present invention are as follows: the frequency domain interference suppression method adopted by the present invention can estimate the self-interference channel without synchronizing the reference signal and the self-interference signal, solves the self-interference suppression problem of the interference detection and reception common platform, and reduces the complexity of the self-interference suppression of the interference detection and reception common platform. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 is a flow chart of the method of the present invention;

[0010] Figure 2 Schematic diagram of the training mode principle of the full-time electronic jamming system in the embodiment;

[0011] Figure 3 Schematic diagram of the reconnaissance mode principle of the full-time electronic jamming system in the embodiment;

[0012] Figure 4 4 is a frequency domain interference suppression performance diagram of the full-time electronic jamming system in the embodiment. DETAILED DESCRIPTION

[0013] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings, but the protection scope of the present invention is not limited to the following.

[0014] like Figure 1 As shown, a full-time electronic jamming system transmission and reception method, the full-time electronic jamming system includes a jammer and a reconnaissance receiver, the method comprising the following steps:

[0015] S1. The jammer generates an interference signal with a period of N, performs digital-to-analog conversion and up-conversion operations, and then transmits it;

[0016] S2. The reconnaissance receiver enters training mode, down-converts the self-interference and reference signals, performs analog-to-digital conversion, and caches them in a 2N-length buffer. N of these data are then selected and converted to the frequency domain for self-interference channel estimation.

[0017] S3. The reconnaissance receiver enters reconnaissance mode, down-converts the received and reference signals, performs analog-to-digital conversion, and caches them in a 2N-length buffer. N of the data are selected and transformed into the frequency domain. The reference signal and channel estimate are used to reconstruct and cancel the self-interference signal. The receiver then inversely transforms the signal back into the time domain to obtain the target signal.

[0018] Wherein, the step S1 includes the following sub-steps:

[0019] S101. The jammer generates a periodic sequence x(n) of length N, performs digital-to-analog conversion and up-conversion on it, and obtains the jamming signal s(t):

[0020]

[0021] Among them, f

[0032] , f ,

[0030] , si , s ,

[0028] , , s , si , si , ,

[0034] , r , , , s ,

[0031] , si , s ,

[0029] , r ,

[0033] , f , -j(2πΔf(n-D)+Δθ)+ω , , s , , , s , , θ s respectively represent the carrier frequency and the initial phase of the jammer.

[0022] S102. The jammer transmits a jamming signal as the self-jamming signal of the reconnaissance receiver under the same platform.

[0023] Among them, the step S2 includes the following sub-steps:

[0024] S201. The reconnaissance receiver enters the training mode, and the received self-jamming signal can be expressed as after down-conversion

[0025]

[0026] where h si represents the self-jamming channel gain, f r represents the operating frequency of the reconnaissance receiver, θ r represents the phase of the reconnaissance receiver, and ω(t) represents thermal noise.

[0027] S202. After the analog-to-digital conversion operation of the self-jamming signal r si (t), it can be expressed as

[0028] r si (n) = h si x(n - D)e -j(2πΔf(n-D)+Δθ)+ω (n)

[0029] where D = τ / T s represents the normalized propagation delay, T s represents the sampling period, Δf = (f r - f s )T s represents the normalized frequency offset, Δθ = (θ r - θ s )T s represents the normalized phase error, and ω(n) represents thermal noise.

[0030] The reference signal can be expressed as

[0031] r f (n) = x(n)

[0032] S203. The reconnaissance receiver respectively caches the self-jamming signal r si and the reference signal r f starting from the nth moment, n = 1, N, 2N,..., caches a length of 2N, and then selects a signal with a length of N starting from the a (a < N)th signal, which can be respectively expressed as

[0033]

[0034] Obtain a complete self-interference signal \(r\) with length \(N\). si And the reference signal \(r\). f Then, with a period of \(N\), perform a discrete-time Fourier transform to transform it into the frequency domain, which can be respectively expressed as

[0035]

[0036] where \(W(k)\) is the thermal noise.

[0037] S204. Use the reference signal to perform self-interference channel estimation on the received self-interference signal, and the channel estimation value can be obtained

[0038]

[0039] where \(W′(k)=W(k) / R\). f (k). Assume that the actual self-interference channel estimation value is \(H\), then the self-interference channel estimation error is

[0040] where the step S3 includes the following sub-steps:

[0041] S301. The reconnaissance receiver enters the reconnaissance mode and simultaneously receives the self-interference signal and the target signal, which can be expressed as

[0042] r(t)=r si (t)+r d (t)+ω(t)

[0043] where \(r d (t) represents the target signal.

[0044] S302. After the analog-to-digital conversion operation of the received signal \(r(t)\), it can be expressed as

[0045] r(n)=r si (n)+r d (n)+ω(n)

[0046] where \(r d (n) represents the target signal.

[0047] S303. The reconnaissance receiver respectively caches the received signal \(r\) and the reference signal \(r f Starting from the \(n\)th moment, cache a length of \(2N\), and then select a signal with a length of \(N\) starting from the \(a\)th (\(a < N\)) signal, which can be respectively expressed as

[0048] r=r si +r d =[r(n + a + 1)r(n + a + N)]

[0049] rf =[x(n+a+1)x(n+a+N)]

[0050] Then the received signal r and the reference signal r are respectively f With N as the period, discrete time Fourier transform is performed to transform it into the frequency domain. The received signal can be expressed as

[0051] R(k)=R si (k)+R d (k)

[0052] Among them, R d (k) is the frequency domain form of the target signal.

[0053] S304. Channel estimation value obtained using training mode Reconstruct the reference signal to obtain the reconstructed self-interference signal

[0054]

[0055] S305. Subtract the reconstructed self-interference signal from the received signal to obtain a residual signal

[0056]

[0057] Therefore, the residual signal contains the target signal R d (k) and the residual interference signal ΔHR f .

[0058] S306. Perform inverse Fourier transform on the residual signal and transform it into the time domain, which can be expressed as

[0059] Δr(n)=r d (n)+ΔHr f

[0060] Ideally, the residual interference signal ΔHR f Can be ignored, so the target signal r can be obtained from the residual signal Δr(n) d (n) All information.

[0061] In the embodiment of the present application, the reconnaissance receiver may perform subsequent reconnaissance signal processing on the residual signal Δr(n) to obtain required information.

[0062] In the embodiment of the present application, the full-time electronic jamming system includes a training mode and a reconnaissance mode. The training mode obtains the self-interference channel estimation value, such as Figure 2 As shown. The reconnaissance mode reconstructs and cancels the self-interference signal, and then obtains the target signal, as shown Figure 3 shown.

[0063] In the embodiment of the present application, according to the method of the present invention, an interference detection platform model is constructed, and the principle is as follows: Figure 2 Figure 3 As shown. The transmitter transmits an interference signal, and the propagation environment is a multipath channel. Simulation verification was carried out on the MATLAB tool, and the simulation parameters are shown in the following table:

[0064]

[0065] Figure 4 The interference suppression performance under different interference-to-noise ratios is shown in the figure. It can be seen from the figure that as the interference-to-noise ratio increases, the interference suppression performance component increases. When the interference-to-noise ratio is 0dB, the self-interference signal power is equal to the noise power, and the interference suppression performance is about 3dB. When the interference-to-noise ratio is 30dB, the self-interference signal power is 10 times the noise power. 3 times, and the interference suppression performance is about 30dB. This shows that this method can suppress the self-interference signal to near low noise.

[0066] The present invention has been described and illustrated in detail so that those skilled in the art can understand and apply the present invention. Those skilled in the art will appreciate that various modifications and variations based on the above description may be made. Such modifications and variations, provided they do not depart from the spirit and scope of the present invention, are intended to be within the scope of the appended claims.

Claims

1. A method for transmitting and receiving a full-time electronic jamming system, wherein the full-time electronic jamming system comprises a jammer and a reconnaissance receiver, characterized in that: The method comprises the following steps: S1. The jammer generates an interference signal with a period of N, performs digital-to-analog conversion and up-conversion operations, and then transmits it; S2. The reconnaissance receiver enters training mode, down-converts the self-interference and reference signals, performs analog-to-digital conversion, and caches them in a 2N-length buffer. N of these data are then selected and converted to the frequency domain for self-interference channel estimation. S3. The reconnaissance receiver enters reconnaissance mode, down-converts the received and reference signals, performs analog-to-digital conversion, and caches them in a 2N-length buffer. N of the data are selected and transformed into the frequency domain. The reference signal and channel estimate are used to reconstruct and cancel the self-interference signal. The receiver then inversely transforms the signal back into the time domain to obtain the target signal.

2. A full-time electronic jamming system transmitting and receiving method according to claim 1, characterized in that: The step S1 includes the following sub-steps: S101. The jammer generates a periodic sequence x(n) of length N, performs digital-to-analog conversion and up-conversion on it, and obtains the jamming signal s(t): Among them, f s ,θ s Respectively represent the carrier frequency and initial phase of the jammer; S102. The jammer transmits a jamming signal, which serves as a self-jamming signal for the reconnaissance receiver on the same platform.

3. A full-time electronic jamming system transmitting and receiving method according to claim 1, characterized in that: The step S2 includes the following sub-steps: S201. The reconnaissance receiver enters training mode and receives a self-interference signal, which is expressed as: Among them, h si represents the self-interference channel gain, f r represents the operating frequency of the reconnaissance receiver, θ r represents the phase of the reconnaissance receiver, ω(t) represents the thermal noise; S202. Self-interference signal r si (t) After analog-to-digital conversion, it is expressed as: Where D = τ / T s represents the normalized propagation delay, T s represents the sampling period, Δf=(f r -f s )T s represents the normalized frequency deviation, Δθ=(θ r -θ s )T s represents the normalized phase error, ω(n) represents the thermal noise; The reference signal is expressed as: r f (n)=x(n) S203. The reconnaissance receiver respectively transmits the self-interference signal r si With the reference signal r f Starting from the nth moment, n = 1, N, 2N, ..., cache length 2N, and then select signals of length N starting from the ath signal, which can be expressed as: Among them, a <N; Get the complete self-interference signal r of length N si With the reference signal r f , and then perform discrete-time Fourier transform with N as the period, transforming it into the frequency domain, which can be expressed as: Where W(k) is thermal noise; S204. Use the reference signal to perform self-interference channel estimation on the received self-interference signal to obtain a channel estimation value where W′(k)=W(k) / R f (k), assuming that the actual self-interference channel estimation value is H, the self-interference channel estimation error is:

4. A full-time electronic jamming system transmitting and receiving method according to claim 1, characterized in that: The step S3 includes the following sub-steps: S301. The reconnaissance receiver enters the reconnaissance mode and receives the self-interference signal and the target signal at the same time, which is expressed as: r(t)=r si (t)+r d (t)+ω(t) Among them, r d (t) represents the target signal; S302. After analog-to-digital conversion of the received signal r(t), it is expressed as: r(n)=r si (n)+r d (n)+ω(n) Among them, r d (n) represents the target signal; S303. The reconnaissance receiver respectively receives the received signal r and the reference signal r f Starting from the nth moment, cache the length of 2N, and then select the signal of length N starting from the ath signal, which can be expressed as: r=r si +r d =[r(n+a+1)r(n+a+N)] r f =[x(n+a+1)x(n+a+N)] Among them, a <N; Then the received signal r and the reference signal r are respectively f With N as the period, discrete-time Fourier transform is performed to transform it into the frequency domain. The received signal is expressed as: R(k)=R si (k)+R d (k) Among them, R d (k) is the frequency domain form of the target signal; S304. Channel estimation value obtained using training mode Reconstruct the reference signal to obtain the reconstructed self-interference signal: S305. Subtract the reconstructed self-interference signal from the received signal to obtain a residual signal: Therefore, the residual signal contains the target signal R d (k) and the residual interference signal ΔHR f ; S306. Perform inverse Fourier transform on the residual signal and transform it into the time domain, which is expressed as: Δr(n)=r d (n)+ΔHr f Ideally, the residual interference signal ΔHR f Ignore, so the target signal r is obtained from the residual signal Δr(n) d (n) All information.

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