Direction of arrival (DOA) estimation method of virtual two-order array extension

The invention discloses a direction of arrival (DOA) estimation method of virtual two-order array extension, belonging to the processing category of receiving an antenna array signal of a wireless transmission signal. In particular, the method is a method that a steering vector is constructed to be a virtual Volterra filter structure and the beamforming technology and the Lagrange multiplier method technology are combined to carry out direction of arrival (DOA) estimation. The steering vector is constructed to be the virtual Volterra filter structure and the beamforming technology and the Lagrange multiplier method technology are combined to carry out direction of arrival (DOA) estimation. According to the algorithm, the DOA estimation under the condition of an unknown number of signal sources can be realized and does not rely on subspace decomposition. The influence of the wrong estimation of the number of the signal sources on the performance of DOA estimation is avoided, the DOA estimation resolution abili