Research On DOA Estimation And Beamforming Algorithm Of Radar Array Signal Based On Component Separation Theory

Compared with a single receiver,the receiver array,which was formed by multiple units according to certain rules,could help the radar system obtain higher spatial resolution.Therefore,the array signal processing technology based on radar system has developed rapidly in recent years and has become a hot research direction.But it ignores the influence of array errors when target detection under ideal assumptions.So it is easy to cause the dilemma that performance of the algorithm was greatly degraded or even invalid in practicahel applications.Aiming at the above problems,based on the linear uniform array,this paper integrates the signal component separation theory with the array signal processing,and explores the realization of radar array signal anti-error processing.Aiming at the performance of traditional estimation algorithms is degraded or even invalid when lack of signal prior knowledge or existence array error,a method based on blind source separation technique is proposed.Blind source separation could estimate the array shape and source signal based on the statistical characteristics of the received signal,avoiding the influence of the array error.So the algorithm is robust.Simulation experiments show that the proposed algorithm can accurately estimate the number of signal sources and direction of arrival under the condition of unknown array shape.Furthermore,the algorithm has high estimation accuracy and stable performance when there exists array error.Aiming at the problem that the shape of array cannot be accurately estimated,a blind beamforming method is proposed which used the components signal time-frequency distribution.The method uses fractional Fourier transform to estimate the parameters of the received signal,and then separates the target components through the Intrinsic Chirp Component Decomposition algorithm to reduce the loss of information in the separation process.Finally,the steering vector is estimated according to the time-frequency distribution of the component signal to complete blind beamforming.Simulation experiments show that the proposed algorithm gets a large gain in the main lobe of the beam response in low signal-to-noise ratio environment or there are errors in the array,indicating that the algorithm has a strong ability to suppress noise.