Estimation Method of Direction of Arrival for Noncircular Signals Based on Nested Array

Abstract

The invention discloses a noncircular signal direction-of-arrival angle estimation method based on a nested array and mainly solves the problems of low utilization rate of array elements, small identified source number and low non-circular signal characteristic utilization rate in the prior art. The method is characterized by 1) obtaining an output signal of the nested array, calculating a covariance matrix and an elliptic covariance matrix according to the signal, constructing an equivalent covariance vector and an equivalent elliptic covariance vector and calculating dimensions of all elements in the two vectors; 2) calculating a virtual array covariance vector and a virtual array elliptic covariance vector, constructing a direction-of-arrival angle selection matrix and calculating a noise subspace thereof; 3) obtaining a first noise matrix and a second noise matrix according to the noise subspace, and constructing a polynomial equation according to the two noise matrixes; and 4) calculating the root of the polynomial equation to obtain a target direction-of-arrival angle value. The method improves the array- recognizable source number under a noncircular signal environment, and can be used for target reconnaissance and passive location.

Description

technical field [0001] The invention belongs to the technical field of signal processing, in particular to a method for estimating the direction of arrival angle of array signals of electromagnetic signals, which can be used for reconnaissance and passive positioning of moving targets of aircraft and ships. Background technique [0002] Signal DOA estimation is an important branch in the field of array signal processing. It refers to the use of antenna arrays to inductively receive spatial acoustic signals and electromagnetic signals, and then use modern signal processing methods to quickly and accurately estimate the direction of the signal source. , has important application value in radar, sonar, wireless communication and other fields. With the continuous advancement of science and technology, there are higher and higher requirements for the degree of freedom that the array can achieve when estimating the signal direction of arrival. [0003] In modern signal processing...

AI Technical Summary

Problems solved by technology

This method has the ability to estimate the number of signals that are more than the number of array elements, but there is still a shortcoming in this method. The discussion of nested arrays is focused on the condition that the received signal is a circular signal. How to use nested arrays The processing of non-circular signals has not yet been studied

[0005] In practical applications, for a non-circular signal environment, given a certain number of array elements, if these array elements and the non-circular characteristics of the signal cannot be reasonably utilized, enough signals cannot be estimated, resulting in a waste of reconnaissance and positioning resources

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