Joint DOA and frequency estimation based on spatio-temporal co-prime sampling

The problem of joint frequency and direction of arrival (DOA) estimation for multiple narrowband signals is addressed here. Previous work has employed co-prime arrays and co-prime samplers to estimate the frequency and DOA individually. Though this can increase the degrees of freedom (DOFs) in the space or time domain, the drawback lies in that it requires an extra procedure to pair these two kinds of parameters. In this work, we extend the one dimensional co-prime spatial and temporal sampling into simultaneous two dimensional co-prime sampling. It enables us to do efficient joint estimation of both frequency and DOA and to get much higher DOFs with the produced spatial-temporal co-array. Meanwhile, to fully utilize the virtual aperture produced in the spatial-temporal co-array, a sparse representation model is considered. Numerical simulation results show its superior performance and verify the effectiveness of the proposed method.