A kind of satellite navigation anti-jamming array array antenna discordance update the system and method
Technical field
The invention belongs to self adaptation array antenna technical field, relate to a kind of satellite navigation anti-jamming array array antenna discordance update the system and method.
Background technology
On ground with aerial, satellite navigation signals is the faintest, and little same frequency electromagnetic radiation just can affect the receptivity of satellite navigation receiver.Therefore, satellite navigation receiver is highly prone to the impact of the malicious interference from enemy and other signal.In order to solve the interference problem of satellite navigation receiver, using Array Signal Processing to slacken interference signal is the Main Means used.In the design of the anti-interference array of common satellite navigation, antenna is individually designed, and with the range distribution close to half operation wavelength on a planar conductor.The aerial array of this mode, the directional diagram of its each array element is basically identical, need not too much consideration antenna radiation pattern figure problem of inconsistency during signal processing.But, along with the new change of application demand, the anti-interference array of satellite navigation and carrier close-coupled design, form conformal array.In this case, the direction placed due to antenna element is different, and the difference that each antenna is affected by carrier, causes the distortion of directional diagram, causes the directional diagram of antenna serious discordance occur.On hardware realizes, the discordance of antenna loses jamproof effect by causing anti-interference process algorithm to the interference signal that some angular domain is incident.Accordingly, it would be desirable to take certain measure to solve the adverse effect that antenna discordance is brought.
Summary of the invention
It is an object of the invention to the defect overcoming above-mentioned technology to exist, a kind of satellite navigation anti-jamming array array antenna discordance update the system and method are provided, this technical scheme can eliminate the adverse effect that anti-jamming array array antenna problem of inconsistency is brought to signal processing, improves anti-jamming effectiveness.
Its concrete technical scheme is:
A kind of satellite navigation anti-jamming array array antenna discordance update the system, including antenna 1, fixed gain radio-frequency channel, variable gain amplifier 8, wave filter 9, intermediate-freuqncy signal collection and digital signal processing module 10 and gain control module 13, described antenna 1, fixed gain radio-frequency channel, variable gain amplifier 8, wave filter 9, intermediate-freuqncy signal collection are sequentially connected with digital signal processing module 10 and gain control module 13.
Preferably, described fixed gain radio-frequency channel includes that preselection filter 2, fixed gain LNA 3, image-rejection filter 4, frequency mixer 5, channel selection filter 6, intermediate frequency amplifier 7, local oscillator 11 and power splitter 12, described preselection filter 2, fixed gain LNA 3, image-rejection filter 4, frequency mixer 5, channel selection filter 6, intermediate frequency amplifier 7, local oscillator 11 and power splitter 12 are sequentially connected with.
Further, described variable gain amplifier 8 is intermediate frequency variable gain amplifier.
Further, described variable gain amplifier 8 is RF variable gain amplifier.
A kind of satellite navigation anti-jamming array array antenna discordance modification method, comprises the following steps:
Step 1: select the a-road-through road that baseband signal amplitude is the strongest as reference channel;
Step 2: the baseband signal intensity of other passage is compared with reference channel signal intensity, and takes decibel value;
Step 3: above-mentioned decibel value is carried out discretization, it is thus achieved that the gain of the actual employing of each variable gain amplifier;
Step 4: changed the depositor of each variable gain amplifier by gain control module, completes the adjustment of each variable-gain amplifier gain.
Compared with prior art, the invention have the benefit that
The present invention can be modified each channel receiving signal amplitude caused due to antenna discordance is inconsistent, makes anti-interference array normally work.
A kind of satellite navigation anti-jamming array array antenna discordance correction technique of the present invention, can be used in the design of satellite navigation conformal array jamproof system, satellite navigation isomery battle array jamproof system etc., make to be generally not capable of normally playing the conformal array of anti-jamming effectiveness and isomery array obtains good anti-jamming effectiveness.
Accompanying drawing explanation
Fig. 1 is the schematic diagram of the present invention a kind of satellite navigation anti-jamming array array antenna discordance update the system;
Fig. 2 is one satellite navigation anti-jamming array array antenna discordance intermediate frequency correction theory diagram of the present invention;
Fig. 3 is one satellite navigation anti-jamming array array antenna discordance radio frequency correction theory diagram of the present invention;
Fig. 4 is ternary anti-interference array anti-interference output spectrum time jamming-to-signal ratio is 75dB when not being modified;
Anti-interference output spectrum when jamming-to-signal ratio is 75dB when Fig. 5 is the employing intermediate frequency correction of ternary anti-interference array;
Anti-interference output spectrum when jamming-to-signal ratio is 75dB when Fig. 6 is the employing radio frequency correction of ternary anti-interference array.
Detailed description of the invention
With specific embodiment, technical scheme is described in more detail below in conjunction with the accompanying drawings.
See Fig. 1, a kind of satellite navigation anti-jamming array array antenna discordance update the system, including antenna 1, fixed gain radio-frequency channel, variable gain amplifier 8, wave filter 9, intermediate-freuqncy signal collection and digital signal processing module 10 and gain control module 13, described antenna 1, fixed gain radio-frequency channel, variable gain amplifier 8, wave filter 9, intermediate-freuqncy signal collection are sequentially connected with digital signal processing module 10 and gain control module 13.
Fig. 2, Fig. 3 are respectively satellite navigation anti-jamming array array antenna discordance intermediate frequency correction theory diagram of the present invention and radio frequency correction theory diagram.As anti-interference array signal processing system, the signal that the multiple performance of each freedom of Fig. 2 with Fig. 3 is identical receives passage and constitutes.Radio-frequency channel in two kinds of theory diagrams all have employed down coversion structure of superhet.In actual applications, it would however also be possible to employ the radio-frequency channel of other structure, such as superhet secondary down-conversion receiver, direct down-conversion receiver and image suppression receiver etc..In figs. 2 and 3, fixed gain radio-frequency channel is made up of preselection filter 2, fixed gain LNA 3, image-rejection filter 4, frequency mixer 5, channel selection filter 6, intermediate frequency amplifier 7, intermediate-frequency filter 9, local oscillator 11 and power splitter 12 etc..Variable gain amplifier 8 in Fig. 2 is intermediate frequency variable gain amplifier, is placed between fixed gain intermediate frequency amplifier 7 and intermediate-frequency filter 9.Variable gain amplifier 8 in Fig. 3 is RF variable gain amplifier, is placed between fixed gain LNA 3 and image-rejection filter 4.Gain control module 13 controls the gain of each variable gain amplifier, signal more weak for signal in each reception passage is carried out the amplification of bigger multiple, making to enter intermediate-freuqncy signal collection roughly the same with each road intermediate-freuqncy signal intensity of digital signal processing module 10, general and reference channel signal intensity difference controls at ± 1dB.
Technical scheme is with each channel baseband signal amplitude meansigma methods within certain sampling time as foundation, and on the basis of first passage signal amplitude meansigma methods, not processing higher than it, less than its gain then increasing this passage.Variable gain amplifier can be designed by two ways, one be this module is arranged on intermediate frequency fixed gain module after, one be this module is arranged on radiofrequency low-noise amplification module after.The gain dynamic range of variable gain amplifier determines according to antenna radiation pattern each in aerial array maximum difference in the scope of interested spatial domain.The amplitude average value of each channel baseband signal that described receiving intermediate frequency signal collection and digital signal processing module are calculated, and the gain of the variable gain amplifier of each passage is set according to described gain control strategies.
A kind of satellite navigation anti-jamming array array antenna discordance modification method, comprises the following steps:
Step 1: select the a-road-through road that baseband signal amplitude is the strongest as reference channel;
Step 2: the baseband signal intensity of other passage is compared with reference channel signal intensity, and takes decibel value;
Step 3: above-mentioned decibel value is carried out discretization, it is thus achieved that the gain of the actual employing of each variable gain amplifier;
Step 4: changed the depositor of each variable gain amplifier by gain control module, completes the adjustment of each variable-gain amplifier gain.
Use a kind of unit tilted-putted ternary anti-interference array that the present invention is verified.The direction placed due to three antenna elements is different, result in obvious antenna problem of inconsistency.Having separately verified discordance intermediate frequency correction and the effect of radio frequency correction, Anti-interference algorithm have employed Power-inversion algorithm, and interference signal is continuous wave CO_2 laser signal.Anti-interference output spectrum when jamming-to-signal ratio is 75dB when Fig. 4 is not for being modified.From fig. 4, it can be seen that owing to not carrying out discordance correcting process, there is no anti-jamming effectiveness after anti-interference process.Fig. 5 gives anti-interference output spectrum after employing intermediate frequency correction, it can be seen that interference signal has been suppressed to the level close to noise level.Fig. 6 gives anti-interference output spectrum after employing radio frequency correction, it can be seen that interference signal has also been suppressed to the level close to noise level.In the case of two kinds, interference signal is inhibited by about 50dB, and the signal after suppression can resolve location normally.
Comprehensive above analysis is visible, a kind of satellite navigation anti-jamming array array antenna discordance correction technique of the present invention, it is possible to be modified the discordance of antenna, meet the demand of the anti-interference Array Signal Processing of satellite navigation.It is demonstrated experimentally that technical scheme can reduce the amplitude difference of satellite navigation jamproof system each passage received signal, anti-interference process is made to obtain good anti-jamming effectiveness.
The above; it is only the present invention preferably detailed description of the invention; protection scope of the present invention is not limited to this; any those familiar with the art is in the technical scope of present disclosure, and the simple change of the technical scheme that can become apparent to or equivalence are replaced and each fallen within protection scope of the present invention.