Method for estimating direction of arrival and information source number of strong and weak signals

Abstract

The invention discloses a method for estimating a direction of arrival and an information source number of strong and weak signals, which mainly solves the problem that the conventional method cannot accurately estimate the direction of arrival of the strong and weak signals when the information source number is unknown. The method comprises the following implementing processes: estimating a covariance matrix according to array receiving data; performing characteristic decomposition on the covariance matrix to acquire characteristic values arranged in a descending order and corresponding characteristic vectors; calculating spatial spectrums of characteristic beams in turn from the first characteristic vector; and estimating the direction of arrival and the information source number of each signal by comparing the difference between a maximum value of the spatial spectrums and an average value outside a main lobe beam width with a set threshold value. The method is simple and practical, can accurately estimate the direction of arrival and the information source number of the strong and weak signals when a plurality of strong and weak signals are coexistent, and can be used for extracting information or suppressing interference in numerous fields of radar, communication, navigation, measurement and control and electronic reconnaissance.

Description

technical field [0001] The invention belongs to the technical field of signal processing and relates to spatial spectrum estimation, which can be used to simultaneously estimate the direction of arrival and the number of signal sources of strong and weak signals when there are multiple strong and weak signals, so as to further extract other signal information or suppress interference. Background technique [0002] Direction of arrival estimation is an important branch of array signal processing, and its applications involve many fields such as radar, communication, navigation, measurement and control, and electronic reconnaissance. Direction of arrival estimation methods based on spatial spectrum, such as maximum likelihood (ML: Maximum likelihood), multiple signal classification (MUSIC: Multiple Signal Classification), rotation invariant signal parameter estimation technique (ESPRIT: Estimation of Signal parameters Via RotationalInvariance Technique) And weighted subspace f...

AI Technical Summary

Problems solved by technology

[0004] 1.J.Li et al. published the article "Angle and Waveform Estimation Via RELAX" on IEEE Transaction on Aerospace and Electronic Systems in 1997, and proposed to estimate the angle of arrival and waveform of the signal by iterative method. In this method, repeated iterations are required. Therefore, the amount of calculation is quite large

[0005] 2. Chen Hui, the JJM method proposed by Su Haijun in "A New Method for DOA Estimation under Strong Interference / Signal Background" published in the Journal of Electronics in 2006, uses the blocking matrix to suppress the strong signal, and then estimates the weak signal, but This method requires that the direction of arrival of the strong signal be known accurately, which is difficult to meet in practice; and when the angle of the strong and weak signals is very close, the weak signal will be affected while the strong signal is suppressed

However, this method needs to pay an additional calculation of eigendecomposition and searching for the maximum value of each channel, and the direction finding performance is affected by the fluctuation of the maximum value of the data segment.

[0007] The above three methods are all proposed under the assumption that the number of signal sources is known, but when strong and weak signals exist at the same time, the number of signal sources is also difficult to estimate. If the estimation is not accurate, it will directly lead to the omission of the direction of arrival. and overestimation, affecting the correct extraction of other information

Images