Wideband DOA estimation for uniform linear arrays based on the co-array concept

A novel design for wideband uniform linear arrays (ULAs) with the associated group-sparsity based direction-of-arrival (DOA) estimation method is proposed. This design allows the number of source signals to significantly exceed the number of sensors. Linear frequency modulated continuous wave (LFMCW) is used as the transmitted signal to ensure the required correlation property among different frequencies. The received echo signals from multiple targets are decomposed into different frequencies by discrete Fourier transform (DFT). Then these frequency bins are divided into several pairs to increase the degrees of freedom (DOFs) based on the co-array concept in the spatio-spectral domain. Group sparsity based signal reconstruction method is employed to jointly estimate the DOA results across multiple frequency pairs. Simulation results demonstrate a significantly improved performance achieved by the proposed method.