An active radio frequency interference nulling method

Abstract

The present invention discloses an active radio frequency interference nulling method, comprising the following steps: S1. The interference node J1 transmits an interference signal to the target interference area; S2. The interference node J2 determines the interference transmission signal waveform, power, phase and relative delay according to the interference information of the interference node J1, generates the interference transmission signal of the interference node J2, and enables the target interference area to achieve radio frequency interference nulling; S3. The legal receiving node U1 in the target interference area receives the signal. The method provided by the present invention can achieve radio frequency interference nulling in the target nulling area while interfering with the enemy's electromagnetic equipment, and ensure that the legal receiving node is not affected by the interference, which has important guiding significance for the flexible engineering application of unmanned interference nodes.

Description

Technical Field

[0001] The invention relates to the field of interference countermeasure, and in particular to an active radio frequency interference nulling method. Background Art

[0002] In modern electronic warfare, manned or unmanned jamming nodes are often dispatched to jam target enemy areas, in order to control electromagnetic dominance in the combat area, clarify battlefield situation, and optimize combat strategies. However, due to the open nature of wireless channels, existing jamming strategies are difficult to distinguish between friend and foe when jamming the target area.

[0003] In order to ensure the signal reception quality of the legitimate receiving nodes of the party while interfering with the enemy's electromagnetic equipment, existing research has mainly proposed interference nulling schemes assisted by multiple antennas or intelligent metasurfaces, regional planning schemes, and active interference suppression schemes. However, in the interference nulling scheme assisted by multiple antennas or intelligent metasurfaces, the area of ​​the interference nulling beam is large. When the legitimate receiving node and the enemy electromagnetic equipment are both in the interference nulling beam, the enemy electromagnetic equipment cannot be effectively interfered. The regional planning method is only applicable to cooperative communication scenarios and has high complexity. The active interference suppression scheme consumes a lot of computing resources and requires the prediction of the interference reference signal. Therefore, it is difficult to apply to modern electronic warfare where the interference characteristics change dynamically.

[0004] In response to the above challenges, the present invention proposes an active RF interference nulling method, which coordinates the waveform, power, phase and relative delay of the signals transmitted by two unmanned interference nodes, and achieves RF interference nulling in the target area while interfering with the enemy's electromagnetic equipment, ensuring that the legitimate receiving nodes are not affected by the interference. This has important guiding significance for the flexible engineering application of unmanned interference nodes. Summary of the invention

[0005] The purpose of the present invention is to overcome the shortcomings of the prior art and propose a new active RF interference nulling method, which achieves RF interference nulling in the target area while interfering with the enemy's electromagnetic equipment by coordinating the waveform, power, phase and relative delay of the signals transmitted by two unmanned interference nodes, ensuring that the legitimate receiving nodes are not affected by the interference.

[0006] The object of the present invention is achieved by the following technical solution: An active radio frequency interference nulling method comprises the following steps:

[0007] S1. The interference node J1 transmits an interference signal to the target interference area;

[0008] S2. The interference node J2 determines the interference transmission signal waveform, power, phase and relative delay according to the interference information of the interference node J1, generates the interference transmission signal of the interference node J2, and realizes the RF interference null sink in the target interference area;

[0009] S3. The legitimate receiving node U1 in the target interference area receives the signal.

[0010] Furthermore, the step S1 includes the following sub-steps:

[0011] S101. Consider a 4-node scenario, including interference node J1, interference node J2, legal receiving node U1, and legal transmitting node U2. The active RF interference nulling strategy aims to set the receiving interference power at the legal receiving node U1 to zero by coordinating the interference transmission waveform, power, phase, and relative delay of the interference nodes J1 and J2 while interfering with the enemy's electromagnetic equipment, so that the legal receiving node U1 is not affected by the interference nodes J1 and J2 when receiving the signal from the legal transmitting node U2.

[0012] The interference node J1 transmits the interference signal J1(t) to the target interference area, which is expressed as

[0013]

[0014] Where P represents the interference transmission power, j(t) represents the baseband interference signal, and f c Indicates the carrier frequency.

[0015] Furthermore, the step S2 comprises:

[0016] S201. The interference node J2 sets its own interference transmission signal waveform as the baseband interference signal j(t) of the interference node J1;

[0017] S202. The interference node J2 determines the interference transmission power P of the interference node J1 and the fading of the propagation channel between the interference node J1 and the legitimate receiving node U1. The fading of the propagation channel between the interference node J2 and the legitimate receiving node U1 Determine the transmission power of the interfering node J2 as

[0018] S203. The interference node J2 determines the carrier frequency f of the interference node J1. c , the delay of the propagation channel between the interference node J1 and the legitimate receiving node U1 The delay of the propagation channel between the interference node J2 and the legitimate receiving node U1 Determine the phase compensation amount of the interference node J2 as The relative delay is

[0019] S204. The interference node J2 generates an interference transmission signal according to the interference transmission signal waveform, transmission power, phase compensation amount, and relative delay amount:

[0020]

[0021] When the interference transmission signal is transmitted to the target interference area, the target interference area can achieve radio frequency interference nulling (that is, the legitimate receiving node U1 in the target interference area is not affected by the interference node J1 and the interference node J2 when receiving the signal).

[0022] Furthermore, the step S3 comprises:

[0023] S301. At the legal receiving node U1, the RF receiving signal can be expressed as

[0024]

[0025] Among them, U2(t) represents the radio frequency communication signal sent by the legal transmitting node U2 to U1. It represents the thermal noise at the legal receiving node U1. It can be found that the legal receiving node U1 is not affected by the interference nodes J1 and J2.

[0026] The beneficial effects of the present invention are as follows: the present invention proposes a new active radio frequency interference nulling method, which can achieve radio frequency interference nulling in the target nulling area while interfering with enemy electromagnetic equipment, ensuring that legitimate receiving nodes are not affected by interference, and has important guiding significance for the flexible engineering application of unmanned interference nodes. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 is a flow chart of the method of the present invention;

[0028] Figure 2 It is the power spectrum and constellation diagram of the received signal at the legal receiving node. DETAILED DESCRIPTION

[0029] The technical solution of the present invention is further described in detail below in conjunction with the accompanying drawings, but the protection scope of the present invention is not limited to the following.

[0030] like Figure 1 As shown, an active radio frequency interference nulling method includes the following steps:

[0031] S1. The interference node J1 transmits an interference signal to the target interference area;

[0032] S101. Consider a 4-node scenario, including interference node J1, interference node J2, legal receiving node U1, and legal transmitting node U2. The active RF interference nulling strategy aims to set the receiving interference power at the legal receiving node U1 to zero by coordinating the interference transmission waveform, power, phase, and relative delay of the interference nodes J1 and J2 while interfering with the enemy's electromagnetic equipment, so that the legal receiving node U1 is not affected by the interference nodes J1 and J2 when receiving the signal from the legal transmitting node U2.

[0033] The interference node J1 transmits the interference signal J1(t) to the target interference area, which is expressed as

[0034]

[0035] Where P represents the interference transmission power, j(t) represents the baseband interference signal, and f c Indicates the carrier frequency.

[0036] S2. The interference node J2 determines the interference transmission signal waveform, power, phase and relative delay according to the interference information of the interference node J1, generates the interference transmission signal of the interference node J2, and makes the target interference area achieve radio frequency interference null (that is, the legitimate receiving node U1 in the target interference area is not affected by the interference node J1 and the interference node J2 when receiving the signal);

[0037] S201. The interference node J2 sets its own interference transmission signal waveform as the baseband interference signal j(t) of the interference node J1;

[0038] S202. The interference node J2 determines the interference transmission power P of the interference node J1 and the fading of the propagation channel between the interference node J1 and the legitimate receiving node U1. The fading of the propagation channel between the interference node J2 and the legitimate receiving node U1 Determine the transmission power of the interfering node J2 as

[0039] S203. The interference node J2 determines the carrier frequency f of the interference node J1. c , the delay of the propagation channel between the interference node J1 and the legitimate receiving node U1 The delay of the propagation channel between the interference node J2 and the legitimate receiving node U1 Determine the phase compensation amount of the interference node J2 as The relative delay is

[0040] S204. The interference node J2 generates an interference transmission signal according to the interference transmission signal waveform, transmission power, phase compensation amount, and relative delay amount:

[0041]

[0042] S3. The legitimate receiving node U1 in the target interference area receives the signal.

[0043] S301. At the legal receiving node U1, the RF receiving signal can be expressed as

[0044]

[0045] Among them, U2(t) represents the radio frequency communication signal sent by the legal transmitting node U2 to U1. It represents the thermal noise at the legal receiving node U1. It can be found that the legal receiving node U1 is not affected by the interference nodes J1 and J2.

[0046] In the embodiment of the present application, from the simulation perspective, the MATLAB tool is used to simulate and verify the performance of the active RF interference nulling method proposed in the present invention, and the simulation parameters are set as follows:

[0047]

[0048] Under the traditional interference strategy and the proposed interference spectrum hole strategy, the power spectrum and constellation diagram of the received signal at the legitimate receiving node are as follows: Figure 2 As shown, the signal reception quality at the legitimate receiving node is characterized. Sub-figures (a) and (b) show that under the traditional interference strategy, the useful signal at the legitimate receiving node is submerged in the interference, and the communication link is blocked by the interference node; sub-figures (a) and (c) show that under the interference spectrum hole strategy proposed in the present invention, the interference signal at the legitimate receiving node is effectively suppressed, verifying the effectiveness of the proposed active RF interference nulling method.

[0049] In summary, in order to solve the practical problem that interference nodes do not distinguish between friend and foe, this paper proposes a new active RF interference nulling method, which can achieve RF interference nulling in the target area while interfering with the enemy's electromagnetic equipment, and ensure that the legitimate receiving nodes are not affected by interference. The simulation results preliminarily verify the effectiveness and feasibility of this method.

[0050] The present invention has been described in detail herein by way of specific embodiments, and the description of the above embodiments is provided to enable those skilled in the art to make or apply the present invention, and various modifications of these embodiments will be readily understood by those skilled in the art. The present invention is not limited to these examples, or certain aspects thereof. The scope of the present invention is described in detail by the appended claims.

[0051] The above description shows and describes a preferred embodiment of the present invention, but as mentioned above, it should be understood that the present invention is not limited to the form disclosed herein, and should not be regarded as excluding other embodiments, but can be used in various other combinations, modifications and environments, and can be modified within the scope of the invention concept described herein through the above teachings or the technology or knowledge of the relevant field. And the changes and modifications made by those skilled in the art do not depart from the spirit and scope of the present invention, and should be within the scope of protection of the claims attached to the present invention.

Claims

1. An active radio frequency interference nulling method, characterized in that: The following steps are involved: S1. The interference node J1 transmits an interference signal to the target interference area; S2. The interference node J2 determines the interference transmission signal waveform, power, phase and relative delay according to the interference information of the interference node J1, generates the interference transmission signal of the interference node J2, and realizes the RF interference null sink in the target interference area; The step S2 comprises: S201. The interference node J2 sets its own interference transmission signal waveform as the baseband interference signal j(t) of the interference node J1; S202. The interference node J2 determines the interference transmission power P of the interference node J1 and the fading of the propagation channel between the interference node J1 and the legitimate receiving node U1. The fading of the propagation channel between the interference node J2 and the legitimate receiving node U1 Determine the transmission power of the interfering node J2 as S203. The interference node J2 determines the carrier frequency f of the interference node J1. c , the delay of the propagation channel between the interference node J1 and the legitimate receiving node U1 The delay of the propagation channel between the interference node J2 and the legitimate receiving node U1 Determine the phase compensation amount of the interference node J2 as The relative delay is S204. The interference node J2 generates an interference transmission signal according to the interference transmission signal waveform, transmission power, phase compensation amount, and relative delay amount: S3. The legitimate receiving node U1 in the target interference area receives the signal.

2. The active radio frequency interference nulling method according to claim 1, characterized in that: The step S1 comprises the following sub-steps: S101. Consider a communication system comprising 4 nodes, including an interfering node J1, an interfering node J2, a legitimate receiving node U1, and a legitimate transmitting node U2; The active RF interference nulling strategy aims to set the receiving interference power at the legitimate receiving node U1 to zero by coordinating the interference emission waveform, power, phase and relative delay of the interference nodes J1 and J2 while interfering with the enemy's electromagnetic equipment, so that the legitimate receiving node U1 is not affected by the interference nodes J1 and J2 when receiving the signal from the legitimate transmitting node U2. The interference node J1 transmits the interference signal J1(t) to the target interference area, which is expressed as Where P represents the interference transmission power, j(t) represents the baseband interference signal, and f c Indicates the carrier frequency.

3. The active radio frequency interference nulling method according to claim 1, characterized in that: The step S3 comprises: At the legal receiving node U1, the RF receiving signal is expressed as Among them, U2(t) represents the radio frequency communication signal sent by the legal transmitting node U2 to U1. represents the thermal noise at the legitimate receiving node U1; therefore, the legitimate receiving node U1 is not affected by the interfering nodes J1 and J2.

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