Direct position determination of non-circular signals based on off-grid sparse reconstruction

Aiming at the problem that the estimation accuracy of the direct position determination (DPD) method based on subspace is not high under the condition of small number of snapshots and low signal-to-noise ratio (SNR), a noncircular signal DPD method based on off-grid sparse reconstruction is proposed. This method combines the non-circular characteristics of the signal to expand the received data and then expand the array aperture. Then, based on the spatial sparsity of the target location, an ultra-complete dictionary set is constructed by discretizing the location area grid, and the problem of target position estimation is transformed into the problem of spatial signal sparse reconstruction. At the same time, considering the signal model that the target is not on the grid point, the joint optimization problem is solved by the alternating iteration method to obtain the estimated value of the target position. Finally, the experimental simulation shows that the method has better positioning performance.