Communication signal recognition method of imitation whale's eye call based on linear frequency modulation signal modulation

Abstract

The invention discloses a communication signal identification method based on a chirp imitation cetacean call modulated by a linear frequency modulation signal, comprising the following steps: (1) denoising and signal extraction of received non-cooperative signals; (2) extracting time-frequency contours (3) Calculate the instantaneous frequency difference of adjacent sampling points, and calculate the mean u and standard deviation of all instantaneous frequency difference data, and set the data interval according to the 3σ criterion, and filter out the abnormal frequency difference located outside the data interval as the frequency The mutation points are sorted according to the time sequence of the occurrence of the frequency mutation points to obtain the total number of frequency mutation points M; (4) extract the instantaneous frequency curves between all adjacent frequency mutation points, and calculate the least squares correlation coefficient of the curve; (5) The time-width data of the chirp signal segment is counted by grouping; and the time interval between adjacent groups of time-width data distribution is calculated to realize the identification and decoding of the communication signal based on the imitation cetacean call modulated by the chirp signal.

Description

Communication signal identification method based on chirp modulation based on cetacean calls technical field The invention belongs to the technical field of communication, particularly a kind of communication based on the imitation cetacean call of chirp modulation. Signal recognition method. Background technique Biomimetic camouflage concealed underwater acoustic communication technology is based on the idea of ​​bionics, by imitating the sound signal of marine mammals. The concealed transmission of current communication information has many advantages such as high concealment and long transmission distance. It plays an increasingly important role in the concealment of transmission. In recent years, an imitation whale based on chirp modulation has been developed. The covert communication method of eye call camouflage has been proposed and widely studied [1], which is based on the vibrato phenomenon in cetacean call signals through The time-frequency profile of th...

AI Technical Summary

Problems solved by technology

This method constructs a communication signal by imitating the real cetacean call, which is very similar to the real cetacean call signal, and it is difficult to distinguish between the two using traditional communication signal recognition methods

If the enemy uses this imitation cetacean call camouflage concealed communication method to communicate, our side will identify the enemy's communication signal as a cetacean call signal and filter it out with a high probability, which makes our country's underwater military operations Security is threatened, so it is urgent to propose a new communication signal identification method to realize the identification of communication signals based on chirp-like cetacean calls modulated by linear frequency modulation signals

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