KR101068103B1 - Active repeater for anti-jamming and method thereof - Google Patents

Abstract

An anti jamming active repeater is disclosed. An active repeater for anti-jamming, comprising: a jamming information receiver for receiving jamming frequency band information from a ground control station; and a hopping frequency excluding a jamming frequency band from all frequency bands of the active repeater using the received jamming frequency band information. The active repeater for anti-jamming comprises a hopping frequency reconstruction unit for extracting a band and reconstructing a hopping frequency of the active repeater in the extracted hopping frequency band. According to the active repeater and the method for the anti-jamming as described above, by reconfiguring the hopping frequency in the frequency band excluding the frequency of the jamming frequency band, there is an effect of avoiding the frequency hopping signal is subjected to jamming interference.

Anti-jamming, hopping frequency, full frequency, anti-jamming frequency, pseudo noise sequence

Description

ACTIVE REPEATER FOR ANTI-JAMMING AND METHOD THEREOF}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an active repeater for anti-jamming and a method thereof, and more particularly, to anti-jamming used in a frequency hopping-frequency division multiple access (FH-FDMA) scheme. active repeater for jamming and a method thereof.

In the conventional military satellite, frequency hopping communication is widely used to maintain data security and to make the signal less affected by noise.

Frequency hopping methods include frequency hopping-code division multiple access (FH-CDMA) and frequency hopping-frequency division multiplexing (FH-FDMA). Here, in the FH-CDMA method, a communication method is performed using a hopping frequency pattern determined for each user. In the FH-FDMA method, a group consisting of a plurality of users is specified in advance, and the hopping frequency pattern is designated for each group. It's a way of communicating.

Since both the FH-CDMA and FH-FDMA schemes change in frequency over time, they are only affected when the frequency band of the enemy's jamming signal matches the hopping frequency band of the active repeater. The effect is also very good.

However, the conventional FH-FDMA scheme is still affected by jamming when the frequency band and the hopping frequency of the jamming signal coincide with each other, so that the integrity of data is degraded. As such, the conventional FH-FDMA scheme does not actively avoid or disable the jamming signal, and therefore, an active complementary measure for anti-jamming is required.

Hereinafter, the problem will be described in more detail through the conventional frequency hopping active repeater.

1 is a block diagram showing a conventional frequency hopping active repeater.

Referring to FIG. 1, the conventional frequency hopping active repeater 100 includes a pseudo noise sequence generation unit 110, a frequency hopping unit 120, and a jammer eliminator 130. This shows the transmitting end of the active repeater 100, the receiving end also includes a corresponding configuration.

The pseudo noise sequence generator 110 generates a kind of code mapped to a predetermined hopping frequency according to the frequency hopping scheme. In the case of the FH-FDMA scheme, a plurality of groups consisting of a plurality of users are specified in advance, and different hopping frequencies are generated for each designated group. At this time, the users of the same group are all assigned the hopping frequencies of the same pattern.

The frequency hopping unit 120 generates a hopping frequency that is previously mapped according to a code generated by the pseudo noise sequence generator 110. Then, the jammer removal unit 130 is configured to remove the jamming signal from the received uplink signal, hop the data signal according to the generated hopping frequency, and then transmit it through the antenna.

In this case, when the hopping frequency generated by the frequency hopping unit 120 spans the frequency band of the jamming signal, the influence of the jamming is left as it is and distortion of the signal occurs.

An object of the present invention is to provide an active repeater for anti-jamming.

Another object of the present invention is to provide an active relay method of an active repeater for anti-jamming.

Active repeater for anti-jamming to achieve the above object of the present invention, a jamming information receiver for receiving jamming frequency band information from the ground control station, and the total frequency of the active repeater using the received jamming frequency band information And a hopping frequency reconstruction unit for extracting a hopping frequency band except for a jamming frequency band and reconstructing a hopping frequency of the active repeater within the extracted hopping frequency band. The active repeater may be configured to operate according to the FH-FDMA scheme. Here, the hopping frequency reconstruction unit may be configured when the collision of each user group is expected to have orthogonality between the hopping frequencies of each user group composed of a plurality of users according to the FH-FDMA scheme. And reconfigure by applying an offset value to the hopping frequency. In addition, the hopping frequency reconstruction unit extracts a hopping frequency band excluding a jamming frequency band from all frequency bands of the active repeater using the received jamming frequency band information, and merges the extracted hopping frequency bands in a continuous hopping frequency. The hopping frequency band mapping unit for mapping to one predetermined frequency band composed of a plurality of points; and the hopping frequency to have orthogonality between the hopping frequency in the one predetermined frequency band and the hopping frequency of an active repeater for another user group. It may be configured to include an offset applying unit for applying an offset value to the frequency band mapping unit for reconstructing the hopping frequency by mapping the hopping frequency to which the offset value is applied to the frequency on the entire frequency band of the active repeater. On the other hand, the offset applying unit may be configured to apply an offset value when the difference between the hopping frequency in the one predetermined frequency band and the hopping frequency of the active repeater for the other user group is less than a predetermined threshold.

An active relay method of an active repeater for anti-jamming to achieve the above object of the present invention includes the steps of receiving jamming frequency band information from a terrestrial control station, and using the received jamming frequency band information. And extracting a hopping frequency band excluding the jamming frequency band from all frequency bands of the signal and reconstructing the hopping frequency of the active repeater within the extracted hopping frequency band. Here, the active repeater may be configured to operate according to the FH-FDMA scheme. The reconstructing of the hopping frequency may include reconfiguring by applying an offset value to the hopping frequency so that the hopping frequency of each user group composed of a plurality of users is orthogonal to each other according to the FH-FDMA scheme. Can be. The reconstructing of the hopping frequency may include extracting a hopping frequency band excluding the jamming frequency band from all frequency bands of the active repeater using the received jamming frequency band information, and extracting the extracted hopping frequency band. By merging to map to one predetermined frequency band consisting of successive hopping frequencies and to have orthogonality between the hopping frequency within the one predetermined frequency band and the hopping frequency of an active repeater for the other group of users. Applying an offset value to the hopping frequency within the predetermined frequency band, and reconstructing the hopping frequency by mapping the hopping frequency to which the offset value is applied to a frequency on the entire frequency band of the active repeater. . In this case, the applying of the offset value may be configured to apply the offset value when the difference between the hopping frequency in the one predetermined frequency band and the hopping frequency of the active repeater for the other user group is less than or equal to a predetermined threshold.

According to the active repeater and the method for the anti-jamming as described above, by reconfiguring the hopping frequency in the frequency band excluding the frequency of the jamming frequency band, there is an effect of avoiding the frequency hopping signal is subjected to jamming interference.

While the invention is susceptible to various modifications and alternative forms, specific embodiments thereof are shown by way of example in the drawings and will herein be described in detail. However, this is not intended to limit the present invention to specific embodiments, it should be understood to include all modifications, equivalents, and substitutes included in the spirit and scope of the present invention. Like reference numerals are used for like elements in describing each drawing.

The terms first, second, A, B, etc. may be used to describe various components, but the components should not be limited by the terms. The terms are used only for the purpose of distinguishing one component from another. For example, without departing from the scope of the present invention, the first component may be referred to as the second component, and similarly, the second component may also be referred to as the first component. And / or < / RTI > includes any combination of a plurality of related listed items or any of a plurality of related listed items.

When a component is said to be "connected" or "connected" to another component, it may be directly connected to or connected to that other component, but it may be understood that another component may exist in between. Should be. On the other hand, when a component is said to be "directly connected" or "directly connected" to another component, it should be understood that there is no other component in between.

The terminology used herein is for the purpose of describing particular example embodiments only and is not intended to be limiting of the present invention. Singular expressions include plural expressions unless the context clearly indicates otherwise. In this application, the terms "comprise" or "have" are intended to indicate that there is a feature, number, step, operation, component, part, or combination thereof described in the specification, and one or more other features. It is to be understood that the present invention does not exclude the possibility of the presence or the addition of numbers, steps, operations, components, components, or a combination thereof.

Unless defined otherwise, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art. Terms such as those defined in the commonly used dictionaries should be construed as having meanings consistent with the meanings in the context of the related art and shall not be construed in ideal or excessively formal meanings unless expressly defined in this application. Do not.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

2 is a block diagram illustrating an active repeater for anti-jamming according to an embodiment of the present invention.

The active repeater 200 is applied to the active repeater 200 performing communication according to the frequency hopping method. Both the FH-CDMA scheme or the FH-FDMA scheme may be applied. Hereinafter, a description will be given according to the FH-FDMA method, and the FH-FDMA method may be applied mutatis mutandis as it is in the FH-CDMA method.

For reference, although FIG. 2 mainly illustrates a transmitting end of the active repeater 200, the receiving end also includes components corresponding to the transmitting end. Therefore, the same applies to the uplink as the method applied to the downlink signal as shown in FIG.

As shown in Figure 2, the active repeater 200 for the anti-jamming of the present invention is a main component, the pseudo noise sequence generator 210, jamming information receiver 220, hopping frequency reconstruction unit 230, The frequency hopping part 240 and the jammer removing part 250 may be configured to be included. Here, the hopping frequency reconstruction unit 230 may include a hopping frequency band mapping unit 231, an offset applying unit 232, and an entire frequency band mapping unit 233. Hereinafter, each configuration will be described in detail.

The pseudo noise sequence generator 210 is a component for generating a pseudo noise sequence for generating a hopping frequency according to the FH-FDMA frequency hopping method. The pseudo noise sequence is a kind of code previously promised between the mobile terminal (not shown) or the ground control station (not shown) and the active repeater 200, and thus a hopping frequency may be generated and output.

The jamming information receiver 220 is a component for receiving jamming frequency band information from the ground control station. Here, the jamming frequency band information means information about a frequency band of the jamming signal intentionally generated. This jamming frequency band information may be configured to be sensed and received from the terrestrial control station.

The hopping frequency reconstruction unit 230 is configured to extract and reconstruct only hopping frequencies which are not interfered by the jamming signal among predetermined hopping frequencies according to a pseudo noise sequence. That is, it is a structure for preventing the frequency hopping to jamming frequency band.

The hopping frequency reconstruction unit 230 first extracts the hopping frequency band excluding the jamming frequency band from all frequency bands of the active repeater 200 by using the jamming frequency band information received from the jamming information receiver 220. And reconstruct the hopping frequencies in the extracted hopping frequency band.

In this case, when the active repeater 200 communicates according to the FH-FDMA scheme, a hopping frequency is assigned to each user group composed of several users. More precisely, a hopping frequency band is allocated and within each hopping frequency band, a hopping frequency is assigned to each user. Therefore, it can be easily seen that each user's hopping frequency has the same hopping pattern.

As described above, in the case of the FH-FDMA scheme, the hopping frequency reconstruction unit 230 operates to have orthogonality between the hopping frequencies of each user group. More precisely, it operates to have orthogonality between group frequency bands. At this time, each user group has a respective hopping frequency pattern. Each user group may be configured to be assigned a separate active repeater, respectively.

In this case, the orthogonal signal means a signal having strong auto-correlation in the frequency hopping method. In order for the auto correlation to be strong, there should be no interference between the group frequency bands.

Thus, the hopping frequency reconstruction unit 230 may be configured to apply an offset value to the hopping frequency such that between the group frequency bands have orthogonality to each other. This will be described in detail with reference to FIG. 4 to be described later.

Meanwhile, the hopping frequency reconstruction unit 230 may be divided into a hopping frequency band mapping unit 231, an offset applying unit 232, and an entire frequency band mapping unit 233.

Hereinafter, the operation of each component of the hopping frequency reconstruction unit 230 will be described with reference to FIGS. 3 to 5.

The hopping frequency band mapping unit 231 is configured to extract a frequency band without interference of the jamming signal and map a predetermined frequency band.

First, a hopping frequency band excluding the jamming frequency band is extracted from all frequency bands of the active repeater using the jamming frequency band information received from the jamming information receiver 220. Then, the extracted hopping frequency bands are merged to map to one predetermined frequency band composed of successive hopping frequencies.

Referring to FIG. 3A, the entire frequency band is represented by 0 to 65,535 as a code. This is because assuming that the number of output bits of the pseudo noise sequence generator 210 is 16 bits, the frequency value corresponding thereto is 16 powers of 2, that is, 65536.

Referring to FIG. 3B, it can be seen that the entire frequency band is converted into a predetermined frequency code. Here, the frequency code may be represented by a total of 13 bits, it is possible to represent a frequency code from 0 to 8000. In addition, it is assumed that the jamming frequency bands on the frequency code are 0 to 500 bands and 2500 to 3334 bands. Removing this jamming frequency band leaves a hopping frequency band consisting of uninterrupted hopping frequencies of the jamming signal.

In FIG. 3C, the hopping frequency bands are merged and continuously arranged from 0 Hz to represent one predetermined frequency band. Thus, in the hopping frequency band in which the frequency code 2500 is merged, it is represented as 2000. Similarly, frequency code 8000 is converted to frequency code 6665.

Then, the corresponding hop frequency is calculated using the converted frequency code. The reason for collecting these hop frequencies to form a single merged frequency band is to check the orthogonality of each hopping frequency from the calculated hopping frequency and add orthogonality.

Table 1, below, logically illustrates this sequence of processes.

Internal_mapped_code_1 = int [PNGcode_1 / 2 ^ 16) * (HB-FBW1-FBW2)]
Internal_mapped_code_2 = int [PNGcode_2 / 2 ^ 16) * (HB-FBW1-FBW2)]

Here, HB (Hopping bandwidth) is the bandwidth of the hopping frequency, FBLL1 (1st forbidden band lower limit) means the lower limit of the first forbidden band, that is, the lower limit of the jamming frequency band, FBW1 (1st forbidden band width) is the first forbidden bandwidth, , Bandwidth of jamming frequency, 2nd forbidden band lower limit (FBLL2) means the lower limit of the second forbidden band, that is, the lower limit of the jamming frequency band, FBW2 (2nd forbidden band width) represents the second forbidden bandwidth, that is, the bandwidth of the jamming frequency .

In addition, PNGcode_1 and PNGcode_2 mean frequency code values, and (HB-FBW1-FBW2) is a size of a bandwidth obtained by merging hopping frequency bands excluding jamming frequency bands among all frequency bands of the active repeater 200.

Therefore, Internal_mapped_code_1 and Internal_mapped_code_2 mean the frequencies of each active repeater, that is, each user group, and become actual frequency values that can be corresponded on the bar graph shown in FIG.

Next, the offset applying unit 232 applies an offset value to the hopping frequency in order to have orthogonality between the hopping frequency in the one predetermined frequency band and the hopping frequency of the active repeater for the other user group.

Referring to FIG. 4, each user group corresponding to each active repeater represents a frequency at which the user jumps over time. In this case, orthogonality may be maintained by maintaining a predetermined interval without interfering with each other between frequencies of a user group, more precisely, between group frequency bands.

However, since the frequency band that can actually jump due to the interference of the jamming signal is reduced, the orthogonality is often affected.

The offset applying unit 232 may be configured to apply an offset value when the difference between the hopping frequency in the one predetermined frequency band and the hopping frequency of the other user group is less than or equal to a predetermined threshold. In other words, the offset value is not applied when it is over the threshold.

At this time, considering the group bandwidth of the active repeater 200 and the characteristics of the SAW filter included in the active repeater 200, the code value of the threshold may be set to 600, the offset value is also 600 desirable.

Table 2 below shows a logical operation of the serial operation of the offset applying unit 232.

Active Repeater 1
If abs (internal_mapped_code_1-internal_mapped_code_2) <600
Then If internal_mapped_code_1> internal_mapped_code_2
Then mapped_code_1 = (internal_mapped_code_1 + 600) mod (HB-FBW1-FBW2)
Else mapped_code_1 = internal_mapped_code_1
End
End

Active repeater 2
If abs (internal_mapped_code_1-internal_mapped_code_2) <600
Then If internal_mapped_code_2> internal_mapped_code_1
Then mapped_code_2 = (internal_mapped_code_1 + 600) mod (HB-FBW1-FBW2)
Else mapped_code_2 = internal_mapped_code_2
End
End

Referring to Table 2 above, in terms of the active relay 1, when the operating frequency internal_mapped_code_1 of the user group 1 shown in (c) of FIG. 3 is greater than the operating frequency internal_mapped_code_2 of the user group 2, the difference is smaller than the predetermined threshold 600 In order to reduce the interference between each other by adding an offset value of 600 to the large frequency inter_mapped_code_1. If it is less than a predetermined threshold, no offset value is applied. In terms of active repeater 2, it works in accordance with the above.

Next, the full frequency band mapping unit 233 reconstructs the hopping frequency by mapping the hopping frequency to which the offset value is applied to a frequency on the entire frequency band of the active repeater.

That is, in order to maintain orthogonality of the hopping frequencies, the hopping frequencies are merged and re-imagined as shown in FIG. 3 (c).

Referring to FIG. 5, the jamming frequency band removed by the hopping frequency mapping unit 231 is inserted into the merged hopping frequency band shown in FIG. 5A. That is, the original full frequency band is generated.

Thus, the hop frequency reconstructed in the pseudo noise sequence generator 210 may be used as it is according to the pseudo noise sequence. In addition, the frequency does not jump to the jamming frequency band. The offset value is applied to the hopping frequency mapped according to the pseudo noise sequence, thereby maintaining orthogonality, so that interference does not occur between hopping frequencies of each user group.

The frequency hopping unit 240 outputs the hopping frequency reconstructed by the hopping frequency reconstruction unit 230 according to the pseudo noise sequence generated by the pseudo noise sequence generation unit 210. If the jamming information is not received at the jamming government receiver 220, the jamming information receiver 220 may operate according to the conventional active repeater.

The jammer remover 250 removes the jammer as the data signal hops by the hopping frequency output from the frequency hop unit 240. The downlink is then transmitted to the ground control station or the like.

Hereinafter, an active relay method of an active repeater for anti-jamming according to an embodiment of the present invention.

6 is a flowchart illustrating an active relay method of an active repeater for anti-jamming according to an embodiment of the present invention.

Referring to FIG. 6, first, the jamming information receiver 210 receives jamming frequency band information from a ground control station. (S100) If not, the pseudo noise sequence generated by the pseudo noise sequence generator 210 is received. Generate and output the hopping frequency already set according to (S700).

Next, the hopping frequency band mapping unit 231 extracts the hopping frequency band excluding the jamming frequency band from all frequency bands of the active repeater 200 by using the received jamming frequency band information.

The hopping frequency band mapping unit 231 merges the extracted hopping frequency bands into one predetermined frequency band composed of successive hopping frequencies (S300).

Next, the offset applying unit 232 provides an offset value to the hopping frequency in the predetermined frequency band to have orthogonality between the hopping frequency in the one predetermined frequency band and the hopping frequency of the active repeater for the other user group. (S400)

Here, the offset value may be configured to be applied when the difference between the hopping frequency in the one predetermined frequency band and the hopping frequency of the active repeater for the other user group is less than or equal to a predetermined threshold.

On the other hand, the full frequency band mapping unit 233 reconstructs the hopping frequency by mapping the hopping frequency output from the offset applying unit 232 to the frequency on the entire frequency band of the active repeater 200 (S500).

The logical operation is shown in Table 3 below.

If it drops interval [(FBLL1, FBLL2-FBW1) it is added FBW1;
if it is> = than (FBLL2-FBW1) it is added (FBW1 + FBW2)

As described above, the entire frequency band mapping unit 233 may be mapped to the entire frequency band by adding FBW1 or FBW1 + FBW2 according to the frequency.

Finally, the frequency hop unit 240 generates and outputs the reconstructed hopping frequency according to the pseudo noise sequence generated by the pseudo noise sequence generator 210. (S600)

Of course, next, the jammer eliminator 250 removes the jammer as it hops by the output hop frequency and transmits a signal to the downlink.

Although described with reference to the embodiments above, those skilled in the art will understand that the present invention can be variously modified and changed without departing from the spirit and scope of the invention as set forth in the claims below. Could be.

1 is a block diagram illustrating an active repeater according to a frequency hopping scheme according to the prior art.

2 is a block diagram illustrating an active repeater for anti-jamming according to an embodiment of the present invention.

3 is a conceptual diagram illustrating a hopping frequency band mapping operation of an active repeater for anti-jamming according to an embodiment of the present invention.

4 is a conceptual diagram for applying an offset of an active repeater for anti-jamming according to an embodiment of the present invention.

5 is a conceptual diagram illustrating an entire frequency band mapping operation of an active repeater for anti-jamming according to an embodiment of the present invention.

6 is a flowchart illustrating an active relay method of an active repeater for anti-jamming according to an embodiment of the present invention.

<Explanation of symbols for the main parts of the drawings>

110: pseudo noise sequence generator 120: frequency hopping

130: jammer remover 210: pseudo noise sequence generator

220: jamming information receiver 230: hopping frequency reconstruction unit

231: hopping frequency band mapping unit 232: offset applying unit

233: all frequency band mapping unit 240: frequency hopping unit

250: jammer removal unit

Claims (10)

delete delete In an active repeater for anti-jamming, A jamming information receiver for receiving jamming frequency band information from a ground control station; The hopping frequency reconstruction unit extracts a hopping frequency band excluding the jamming frequency band from all frequency bands of the active repeater using the received jamming frequency band information, and reconstructs the hopping frequency of the active repeater within the extracted hopping frequency band. Including, The active repeater operates according to the FH-FDMA scheme, The hopping frequency reconstruction unit reconfigures by applying an offset value to the hopping frequency so that the hopping frequencies of each user group composed of a plurality of users have orthogonality with each other according to the FH-FDMA scheme. Active repeater for anti jamming. The method of claim 3, The hopping frequency reconstruction unit, One predetermined frequency consisting of consecutive hopping frequencies by extracting a hopping frequency band excluding a jamming frequency band from all frequency bands of the active repeater using the received jamming frequency band information, and merging the extracted hopping frequency bands. A hopping frequency band mapping unit for mapping to bands; An offset applying unit for applying an offset value to the hopping frequency to have orthogonality between the hopping frequency in the one predetermined frequency band and the hopping frequency of an active repeater for another user group; And And an entire frequency band mapping unit configured to reconstruct the hopping frequency by mapping the hopping frequency to which the offset value is applied to a frequency on the entire frequency band of the active repeater. 5. The method of claim 4, And the offset applying unit applies an offset value when the difference between the hopping frequency in the one predetermined frequency band and the hopping frequency of the active repeater for the other user group is less than or equal to a predetermined threshold. delete delete In the active relay method of the active repeater for anti-jamming, Receiving jamming frequency band information from a ground control station; Extracting a hopping frequency band excluding a jamming frequency band from all frequency bands of the active repeater using the received jamming frequency band information; Reconstructing the hopping frequency of the active repeater within the extracted hopping frequency band, The active repeater operates according to the FH-FDMA scheme, The reconfiguring of the hopping frequency may include reconfiguring by applying an offset value to the hopping frequency so that the hopping frequencies of each user group composed of a plurality of users are orthogonal to each other according to the FH-FDMA scheme. Active relay method. The method of claim 8, Reconstructing the hopping frequency, Extracting a hopping frequency band excluding a jamming frequency band from all frequency bands of the active repeater using the received jamming frequency band information; Mapping the extracted hopping frequency bands into one predetermined frequency band consisting of successive hopping frequencies; Applying an offset value to the hopping frequency within the predetermined frequency band to have orthogonality between the hopping frequency within the one predetermined frequency band and the hopping frequency of an active repeater for the other user group; And reconstructing the hopping frequency by mapping the hopping frequency to which the offset value is applied to a frequency on the entire frequency band of the active repeater. 10. The method of claim 9, The applying of the offset value may include applying an offset value when the difference between the hopping frequency in the one predetermined frequency band and the hopping frequency of the active repeater for the other user group is less than or equal to a predetermined threshold.

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