Research On Direction Of Arrival Estimation Algorithm Of Noncircular Signal

Direction of arrival(DOA)estimation is one of the key techniques in array signal processing.Noncircular signal is a common signal in modern wireless communications.With the noncircular feature,array aperture is extended.Consequently,the performance of parameter estimation is improved while more signal sources can be estimated.This paper mainly studies the DOA estimation of noncircular signal,which has practical values.The main work is summarized as follows:1)A DOA estimation algorithm of noncircular signal based on estimating signal parameters via rotational invariance techniques(ESPRIT)for uniform linear array is investigated.This algorithm can extend array aperture with the noncircular feature of signal sources.Consequently,the performance of parameter estimation of algorithm is better than ESPRIT algorithm.And a reduced-dimension DOA estimation algorithm of noncircular signal based on multiple signal classification(MUSIC)for linear array is proposed.The proposed algorithms avoid two-dimensional(2D)searching of spectral peak,with the angle estimation performance very close to two-dimensional MUSIC algorithm.2)Aiming at the two dimensional DOA estimation of noncircular signal for L-shape array,DOA estimation algorithms of noncircular signal based on ESPRIT via Euler transformation and Propogator Method(PM)via Euler transformation are investigated.The algorithms can effectively improve the performance of parameter estimation due to use of noncircular characteristics and greatly reduce the computational complexity of the algorithm due to Euler transformation.And aiming at the two-dimensional DOA estimation of noncircular signal for two parallel arrays,a DOA estimation algorithm of noncircular signal based on PM via Euler transformation is investigated.The algorithm can improve the performance of parameter estimation and reduce the computational complexity of the algorithm.3)Aiming at the DOA estimation of mixes signal(circular signal and noncircular signal coexisting)for linear array,DOA estimation algorithms based on Mixed-Capon and Mixed-MUSIC are investigated.The algorithms can effectively estimate DOA of mixed signal without estimating noncircular phase.Simulation results show that the estimation performances of the algorithms are better than the traditional Capon algorithm and MUSIC algorithm,respectively.