KR-20260063531-A - PARALLEL STRUCTURE LINEAR FEEDBACK SHIFT REGISTER DEVICE AND OPERATING METHOD THEREOF

Abstract

A method and apparatus for restoring a frequency hopping signal are disclosed. The method for restoring the frequency hopping signal includes the steps of: tracking a frequency hopping signal received from a transmitter in hop units and converting it into a baseband signal; removing muted intervals of the baseband signal to extract a section where a signal exists; performing FM demodulation on the extracted signal; determining a threshold value for detecting spike components from the FM demodulated signal; and generating a noise-removed signal from the FM demodulated signal based on the threshold value.

Inventors

• 최영익
• 김동호
• 최정우
• 이하늘

Assignees

• 엘아이지디펜스앤에어로스페이스 주식회사

Dates

Publication Date

20260507

Application Date

20241030

Claims (14)

1. A step of tracking a frequency hopping signal received from a transmitter in hop units and converting it into a frequency band signal; A step of extracting a section where a signal exists by removing the muted section of the above-mentioned base band signal; A step of performing FM demodulation on the above extracted signal; A step of determining a threshold value for detecting a spike component from the above FM demodulated signal; and A step of generating a noise-removed signal from the FM demodulated signal based on the above threshold A method for restoring a frequency hopping signal including
2. In claim 1, the step of determining the threshold value is, A method for restoring a frequency hopping signal, characterized by including the step of determining the threshold value based on the moving average filter value of the FM demodulated signal and the Root Mean Square (RMS) value of the data accumulated in sample units.
3. In paragraph 2, the threshold value is, ceremony ' A method for restoring a frequency hopping signal characterized by being determined by (Threshold(n): the threshold value, MF N (n): the moving average filter value of the FM demodulated signal, W rms (n): the RMS (Root Means Square) value of the data accumulated in sample units).
4. In paragraph 2, the step of determining the threshold value is, A step of determining the moving average filter value based on the index number of the current data sample, the total number of data samples, and the value obtained by replacing the restored signal with its absolute value. A method for restoring a frequency hopping signal characterized by including
5. In paragraph 4, the moving average filter value is, ceremony ' A method for restoring a frequency hopping signal characterized by being determined by (MF N (n): moving average filter value of the restored signal, n: index number of the current data sample, N: total number of data samples, x(k): value obtained by substituting the absolute value of the restored signal).
6. In paragraph 2, the step of determining the threshold value is, Step of determining the RMS value based on the index number of the current data sample and the value obtained by replacing the restored signal with its absolute value A method for restoring a frequency hopping signal characterized by including
7. In paragraph 6, the above RMS value is, ceremony ' A method for restoring a frequency hopping signal characterized by being determined by (n: index number of the current data sample, x(k): value obtained by substituting the absolute value of the restored signal).
8. A communication unit that receives a frequency hopping signal from a transmitter; The frequency hopping signal received by the above communication unit is tracked in hop units and converted into a baseband signal, and The muted section of the above-mentioned baseband signal is removed to extract the section where the signal exists, and FM demodulation is performed on the above extracted signal, and Determining a threshold value for detecting spike components from the above FM demodulated signal, and A processor that generates a noise-removed signal from the FM demodulated signal based on the above threshold A frequency hopping signal restoration device including
9. In paragraph 8, the above processor, A frequency hopping signal recovery device characterized by determining the threshold value based on the moving average filter value of the FM demodulated signal and the RMS (Root Mean Square) value of the data accumulated on a sample-by-sample basis.
10. In Clause 9, the above threshold value is, ceremony ' A frequency hopping signal recovery device characterized by being determined by (Threshold(n): the threshold value, MF N (n): the moving average filter value of the FM demodulated signal, W rms (n): the RMS (Root Means Square) value of the data accumulated in sample units).
11. In paragraph 9, the above processor, A frequency hopping signal recovery device characterized by determining the moving average filter value based on the index number of the current data sample, the total number of data samples, and the value obtained by substituting the absolute value of the recovered signal.
12. In Clause 11, the above moving average filter value is, ceremony ' A frequency hopping signal restoration device characterized by being determined by (MF N (n): moving average filter value of the restored signal, n: index number of the current data sample, N: total number of data samples, x(k): value obtained by substituting the restored signal with its absolute value).
13. In paragraph 9, the above processor, A frequency hopping signal recovery device characterized by determining the RMS value based on the index number of the current data sample and the value obtained by substituting the absolute value of the recovered signal.
14. In Clause 13, the above RMS value is, ceremony ' A frequency hopping signal recovery device characterized by being determined by (n: index number of the current data sample, x(k): value obtained by substituting the absolute value of the recovered signal).

Description

Method and apparatus for recovering frequency hopping signals {PARALLEL STRUCTURE LINEAR FEEDBACK SHIFT REGISTER DEVICE AND OPERATING METHOD THEREOF} The present invention relates to communication technology, and more specifically, to a method and apparatus for restoring a frequency hopping signal. Current military communication systems utilize Frequency Hopping (FH) transmission, which transmits baseband signals using different carriers across a wide frequency band at very short intervals, as part of Electronic Counter-Counter Measure (ECCM) to enhance Low Probability Intercept (LPI) and Anti-Jammer (AJ) performance. Generally, receiving frequency-hopping signals requires essential synchronized information; however, for the specific purpose of recovering unknown signals, it is necessary to detect the frequency-hopping signal without prior information and perform blind demodulation using the received signal. In this case, when a frequency hopping signal is detected without prior information and FM demodulation is performed on the received hop signal, noise with high power in short intervals exists in the restored speech due to hop-mute intervals caused by the maintenance and pause of the signal, and as the hopping rate of the target signal increases, the proportion of such noise in the entire speech interval increases, causing further degradation of the signal quality. Therefore, in this technical field, there is a need for technology that can effectively remove voice noise components caused by hop-mute intervals in a blind environment. Figure 1 schematically shows the structure of a frequency hopping signal recovery device according to an embodiment of the present invention. FIG. 2 shows an example of the amplitude component of a signal converted into a baseband signal by tracking a received frequency hopping signal in hop units to which the present invention can be applied. Figure 3 shows a signal obtained by extracting only the interval where the signal exists from the signal of Figure 2. Figure 4 shows an example of a voice signal restored by FM demodulating the signal of Figure 3. Figure 5 shows an example of comparing the voice signal restored by FM demodulation of Figure 4 with a threshold value according to an embodiment of the present invention. FIG. 6 is a flowchart illustrating an example of a frequency hopping signal recovery method according to an embodiment of the present invention. Figure 7 shows an example of a voice result obtained by FM restoring a typical blind hopping signal. FIG. 8 shows an example of a voice result of FM reconstructing a blind hopping signal according to an embodiment of the present invention. Hereinafter, embodiments disclosed in this specification will be described in detail with reference to the attached drawings. Identical or similar components regardless of drawing symbols will be assigned the same reference number, and redundant descriptions thereof will be omitted. The suffixes "module" and "part" used for components in the following description are assigned or used interchangeably solely for the ease of drafting the specification and do not inherently possess distinct meanings or roles. Furthermore, in describing embodiments disclosed in this specification, if it is determined that a detailed description of related prior art could obscure the essence of the embodiments disclosed in this specification, such detailed description will be omitted. Additionally, the attached drawings are intended only to facilitate understanding of the embodiments disclosed in this specification; the technical concept disclosed in this specification is not limited by the attached drawings, and it should be understood that they include all modifications, equivalents, and substitutions that fall within the spirit and technical scope of the present invention. Terms including ordinal numbers, such as first, second, etc., may be used to describe various components, but said components are not limited by said terms. These terms are used solely for the purpose of distinguishing one component from another. When it is stated that one component is "connected" or "connected" to another component, it should be understood that while it may be directly connected or connected to that other component, there may also be other components in between. On the other hand, when it is stated that one component is "directly connected" or "directly connected" to another component, it should be understood that there are no other components in between. A singular expression includes a plural expression unless the context clearly indicates otherwise. In this specification, terms such as “comprising” or “having” are intended to indicate the existence of the features, numbers, steps, actions, components, parts, or combinations thereof described in the specification, and should be understood as not excluding in advance the existence or addition of one or more other features, numbers, steps, actions, components, pa