Range-Dependent Beamforming Using Space-Frequency Virtual Difference Coarray
Tianheng Ni, Shengheng Liu, Zihuan Mao, Yongming Huang
Abstract
Frequency diverse array (FDA) combines frequency and spatial diversities and, thereby, generates a time-range-angle-dependent beampattern, which is attractive in many application scenarios. Incorporating coprimality in designing the array geometry and the frequency offset yields coprime FDA, whose spatial resolution and degrees of freedom are enhanced. In this paper, we further leverage the second-order statistics to construct the location and frequency of the coprime difference sets of coprime FDA in the virtual domain. The proposed scheme can obtain a decoupled receive beampattern with an enlarged array aperture and a reduced radio-frequency circuit complexity. The advantages of the proposed method is confirmed by the simulation results.