A Simple Ship Radiated Noise Model and Its Application in Weak Signal Detection Based on Higher Order Cumulant In this paper, a simple model of ship radiated noise is designed. Firstly, the characteristics of ship radiated noise are analyzed. Then, according to the characteristics of ship radiated noise, the calculation model of sound field, the line spectrum component and the continuous spectrum component of radiated noise are established respectively, Simple model has the advantages of high calculation efficiency and more practicability. At the same time, we use the simple ship radiated noise model to carry out the application of highorder cumulant in weak signal detection. Experiments and simulation results show that the simple ship radiated noise model established in this paper is in line with the characteristics of ship radiated noise, and has very good reference and application value. Simultaneously, the simulation results show that the slice spectrum of highorder cumulant has obvious advantages over the power spectrum (secondorder spectrum). Highorder spectrum can effectively extract the harmonic components of radiated noise, and can also be used for the detection of quadratic phase coupling.

CumulantBased DOA Estimation of Noncircular Signals against Unknown Mutual Coupling To effectively find the direction of noncircular signals received by a uniform linear array (ULA) in the presence of nonnegligible perturbations between array elements, i.e., mutual coupling, in colored noise, a direction of arrival (DOA) estimation approach in the context of high order statistics is proposed in this correspondence. Exploiting the noncircularity hidden behind a certain class of wireless communication signals to build up an augmented cumulant matrix, and carrying out a reformulation of the distorted steering vector to extract the angular information from the unknown mutual coupling, by exploiting the characteristic of mutual coupling, i.e., a limited operating range and an inverse relation of coupling effects to interspace, we develop a MUSIClike estimator based on the rankreduction (RARE) technique to directly determine directions of incident signals without mutual coupling compensation. Besides, we provide a solution to the problem of coherency between signals and mutual coupling between sensors coexisting, by selecting a middle subarray to mitigate the undesirable effects and exploiting the rotationinvariant property to blindly separate the coherent signals into different groups to enhance the degrees of freedom. Compared with the existing robust DOA methods to the unknown mutual coupling under the framework of fourthorder cumulants (FOC), our work takes advantage of the larger virtual array and is able to resolve more signals due to greater degrees of freedom. Additionally, as the effective aperture is virtually extended, the developed estimator can achieve better performance under scenarios with high degree of mutual coupling between two sensors. Simulation results demonstrate the validity and efficiency of the proposed method.