Monostatic expansion co-prime array MIMO radar DOA estimation method based on non-circular signals

Abstract

The invention relates to the technical field of radar, and in particular relates to a monostatic expansion co-prime array MIMO radar DOA estimation method based on non-circular signals. The method comprises the steps of sampling data after matched filtering of the receiving array elements to obtain receiving data of an equivalent virtual array; then carrying out conjugate processing and combiningthe receiving data into new expansion receiving data; carrying out spatial covariance matrix and eigenvalue decomposition; constructing a calculation expression of a spatial spectrum according to orthogonality of a noise subspace and a steering vector; and searching positions of K spectral peaks by the spectral peaks to obtain arrival direction estimation of K incoming waves. According to the method, an expansion co-prime array is used as a transmitting array and a receiving array of a MIMO radar; the array space of the transceiving array is greatly expanded; meanwhile, the non-circular signals are used as the transmitting signals of the transmitting array of the MIMO radar; and the DOA estimation performance is greatly improved by combining the non-circular characteristics of the non-circular signals, the excellent spatial resolution and parameter identifiability of the MIMO radar and the triple advantages of expanding the array aperture expanded by the co-prime array.

Description

technical field [0001] The invention relates to the technical field of radar, in particular to a method for estimating the DOA of a monostatic coprime array MIMO radar based on a non-circular signal. Background technique [0002] In recent years, the multiple input multiple output (Multiple Input Multiple Output, MIMO) technical idea in the communication field has been introduced into the radar field, and the proposed MIMO radar system has attracted widespread attention. MIMO radar makes full use of signal diversity and airspace diversity gain to obtain a higher degree of freedom than traditional radar, and its target detection ability and parameter estimation ability have been widely recognized. Due to the many potential advantages of MIMO radars, the research on MIMO radars develops rapidly, and the direction of arrival (Direction Of Arrival, referred to as DOA) estimation of MIMO radars is one of the key research topics. [0003] Most of the current research on MIMO rada...

AI Technical Summary

Problems solved by technology

However, the existing methods treat the coprime array as two sparse uniform arrays separately, so there are the following problems: first, the degree of freedom is limited by the number of subarray elements, which is reduced by at least half compared with the uniform array; second, Further operations are required to remove the ambiguity problem

For DOA estimation based on MIMO radar, the general method is to transplant traditional methods, such as applying the subspace MUSIC method to the two-dimensional MUSIC method and dimensionality reduction MUSIC method of MIMO radar, etc. Large, and not suitable for the method of direction finding using non-circular signals, the performance deteriorates sharply when there are coherent sources, the DOA estimation performance is low or it is difficult to achieve DOA estimation

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