Adaptive Beamforming And Wireless Location Parameter Estimation Based On Correntropy

With the rapid development of radio technology,the monitoring capability of radio should keep pace with the times.The detection and location of radio signals have always been the focus in the field of radio monitoring.As a spatial filtering technique,adaptive beamforming can detect and extract signals well.Because most communication signals have cyclostationary characteristics,cyclostationarity-based adaptive beamforming algorithms have attracted widespread attention.However,most of the traditional cyclostationary based algorithms are sensitive to cyclic frequency error(CFE),which directly affects the actual application effect.In addition,as the important components of wireless passive location parameter estimation,direction of arrival(DOA)and time direction of arrival(TDOA)have attracted widespread attention.In DOA estimation,traditional algorithms were primarily proposed under the assumption of a known number of narrow-band sources.And in time delay estimation,most of the existing studies were based on the assumption of broadband signal and no amplitude attenuation.With the increasing popularity of modern signal processing technology,these assumptions become too restricting,and the limitations of the algorithm become increasingly prominent.In order to solve the above problems,the following innovative research work is carried out for DOA and TDOA estimations and cyclostationality-based adaptive beamforming algorithms:(1)Aiming at the problem that cyclostationarity-based eamforming algorithms is sensitive to CFE.a cyclic frequency estimation algorithm under compressed sampling is proposed based on compressed signal processing(CSP).Based on the relationship between the cyclic spectrum and the frequency shift autocorrelation matrix,the cyclic spectrum is reconstructed without the recovery of the original signal and the cyclic frequency is estimated.Furthermore,considering that it takes a lot of memory cells and computing advance,a robust adaptive beamforming algorithm in the presence of CFE is proposed.In this algorithm.the maximum correlation entropy criterion(MCC)is used to find the weight vector at a given cyclic frequency,and then the correntropy'based correlation(CRCO)function is used as the cost function to adjust the weight vector and cyclic frequency adaptively,and the optimization of the main beam is realized.The proposed algorithm has obvious advantages of beamforming in impulsive noise,especially in highly impulsive noise.(2)To solve the problem of DOA estimation with an unknown number of sources,an algorithm for estimating the number of signal sources based on Cx sparse regularization is proposed.This approximation is accomplished using the sparsity of eigenvalue sequence of signal covariance matrix.The algoritjhm can accurately estimate the number of signals with few snapshots and low SNR condition.Furthermore,in order to reduce the repetitive computation and storage space,a joint estimation algorithm for the number of sources and DOA is proposed.Based on the phase shift characteristic of cyclic correntropy.the linear prediction(LP)model with regularization parameters is established,and the analytical expression of regularization parameters is deduced by using MCC.The proposed algorithm solves the problem that the performance of super-resolution DOA estimation algorithm is limited by signal bandwidth.(3)As signal bandwidth and amplitude limits the accuracy of time delay estimation,the research is applied separately based on correntropy theory.In the application of narrowband signals,a time delay estimation based on correntropy Hilbert transform difference method is proposed.This algorithm can not only keep the value of the time delay estimation of the correntropy function,but also solve the problem that the adjacent pseudo peak points are very similar in amplitude.In the application of amplitude attenuation signal signals,a one-step time delay estimation algorithm is proposed based on FIR filter coefficients.The algorithm uses MCC criterion to estimate recursive solution in the closed form,proving the unbiasedness of the estimation.The algorithm performs well in complex electromagnetic environment with serious amplitude attenuation and high impulsive noise...