Underwater sound signal denoising method based on combination of improved VMD and improved wavelet threshold method

Abstract

The invention discloses an underwater acoustic signal denoising method based on combination of an improved VMD model and an improved wavelet threshold method. The method comprises the following steps: firstly, determining a parameter k in a VMD model based on a kurtosis maximization principle, and determining a secondary penalty term alpha by adopting an improved whale optimization algorithm to obtain an improved VMD model; inputting a source signal into the improved VMD model to obtain a plurality of intrinsic mode functions; and then processing the IMFs by a wavelet threshold method to further remove residual noise, wherein an improved grey wolf optimization algorithm is adopted to optimize a threshold lambda, and finally, the IMFs are reconstructed to obtain a denoised signal. According to the method, signals in a noise environment can be effectively separated, complex ocean noise in an underwater acoustic communication system is suppressed, and the underwater acoustic signal receiving quality and the anti-noise performance are improved.

Description

technical field [0001] The invention belongs to the technical field of mixed acoustic signal denoising, and in particular relates to an underwater acoustic signal denoising method based on an improved VMD model based on a whale optimization algorithm and an improved wavelet threshold method based on a gray wolf optimization algorithm combined with a wavelet threshold method. Background technique [0002] The processing of underwater acoustic signal denoising has always been a research hotspot in the field of underwater acoustic engineering. Aiming at the problem that the transient signal of the sound of objects entering water is difficult to detect at a low signal-to-noise ratio, Li Guanfang and others proposed a detection and direction finding method for the sound of objects entering water based on Empirical Mode Decomposition (EMD). A more satisfactory result was obtained. However, the EMD model has the phenomenon of modal aliasing, and because the algorithm uses recursiv...

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Problems solved by technology

[0004] However, VMD cannot achieve the separation of non-stationary signals in one step

Generally speaking, the current underwater acoustic signal denoising method has made some progress, and is widely used in the fields of marine development and detection, but there are still problems such as incomplete denoising, high algorithm complexity, and easy distortion of the obtained target signal. question

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