DOA estimation by exploiting spatial and Doppler sparsity

The direction of arrival (DOA) estimation of narrowband signals is of great interest in array signal processing. In compressed sensing (CS) field, the DOA estimation can be modelled as a joint-sparse recovery problem. This paper presents a new method to estimate DOAs of narrowband signals with Doppler frequencies, via CS. Different from other CS based DOA estimation methods, most of which utilize spatial sparsity only, the proposed method exploits the source sparsity in both spatial and Doppler frequency domain to improve the performance of DOA estimation. This method preprocesses the received signal of each channel by transforming it to the frequency domain. Then, frequency bands with relatively large values are extracted, and further used to recover the sparse signals so as to estimation of DOAs of the sources. Compared with direct joint-sparse recovery in time domain, this method provides lower computation complexity and higher accuracy. Furthermore, if Doppler frequencies of sources can be distinguished, we can obtain better estimation resolution, with lower requirements for the number of elements.