Communication signal identification method simulating whale sound based on linear frequency modulation signal modulation

Abstract

The invention discloses a communication signal identification method simulating whale sound based on linear frequency modulation signal modulation. The method comprises the following steps: (1) performing denoising and signal extraction on a received non-cooperative signal; (2) extracting a time-frequency contour; (3) calculating instantaneous frequency differences of adjacent sampling points, calculating an average value u and a standard deviation of all instantaneous frequency difference data, setting a data interval according to a 3 sigma criterion, screening out abnormal frequency difference points outside the data interval as frequency mutation points, and sorting according to a sequence of occurrence moments of the frequency mutation points to obtain a total number M of the frequency mutation points; (4) extracting an instantaneous frequency curve between all adjacent frequency mutation points, and calculating a least square correlation coefficient of the curve; (5) performing grouping statistics on the time width data of the chirp signal segments; and calculating a time interval between adjacent groups of time width data distribution, thereby realizing identification and decoding of the whale sound-imitating communication signal based on linear frequency modulation signal modulation.

Description

technical field [0001] The invention belongs to the technical field of communication, in particular to a communication signal identification method based on a whale-like cry modulated by a chirp signal. Background technique [0002] The bionic camouflage concealed underwater acoustic communication technology is based on the bionic idea. It realizes the concealed transmission of communication information by imitating the call signal of marine mammals. It has many advantages such as high concealment and long transmission distance. The concealed transmission of information between underwater military platforms etc. are playing an increasingly important role. In recent years, a method based on linear frequency modulation signal modulation to imitate cetacean call camouflage covert communication has been proposed and widely studied [1]. The signal segment modulates and encodes the time-frequency profile of cetacean call signals, so as to obtain a camouflaged covert communication...

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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