Line spectrum detection method by coherent accumulation of frequency domains

Abstract

The invention provides a line spectrum detection method by coherent accumulation of frequency domains. According to the invention, the method comprises the following steps that: step one, on the basis of time correlation characteristics of a signal field and a noise field, segment processing is carried out on a receiving signal, so that there are time delays between all segments of the signal and a time delay amount is greater than a correlation radius of the noise and is less than a correlation radius of the signal; step two, each the signal segment is internally divided into a plurality of sub data segments and it is allowed that there are overlapping parts of data of all the segments; step three, time delay compensation is carried out on the signal; step four, signals of all the segments are accumulated to obtain an output signal of coherent accumulation; step five, power equalization is carried out on outputs of all correlation accumulations, so that a power spectrum estimated by the method provided in the invention is obtained. According to the invention, coherence of signals is utilized; and phase compensation is carried out on signals, wherein there are time delay differences between all the signals; therefore, same phase addition of the signals is formed; however, because the phase of the noise is random, there is no formed same phase addition for the noise, so that a detection capability on a weak signal can be improved.

Description

technical field [0001] The invention relates to an underwater acoustic signal processing method, in particular to a line spectrum signal detection method. Background technique [0002] Passive sonar detects the target and distinguishes the type of the target based on the radiation noise emitted by the target when it is sailing. High-quality spectral estimation of line spectra will provide an important basis for target recognition. The detection and extraction of line spectrum has always been the focus of research at home and abroad. Currently, line spectrum detection is usually performed based on the calculated spectral values ​​of the periodogram. Line spectrum detection methods are divided into two categories: real-time detection methods using spectral values ​​at a single time point and decision-making methods using multiple time point data to delay decision-making. [0003] The most classic method of line spectrum detection is to directly process the signal received i...

AI Technical Summary

Problems solved by technology

This algorithm solves the problems in line spectrum detection such as breakpoints in the middle of spectral lines and random noise point interference, and improves the ability of line spectrum detection and extraction under low signal-to-noise ratio. However, the initial state of spectral lines affects the algorithm performance. Greater impact

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