A Frequency Domain Direction of Arrival Estimation Algorithm for UAV Remote-control Signal

Abstract

With the popularity of unmanned aerial vehicles (UAVs), security accidents, criminal activities and terrorist incidents related to “black flight” have emerged ceaselessly in the world. However, the “black flight pilot” who caused the incidents is hard to be traced because remote-control signals of the UAV are typically frequency hopping (FH) signals with extremely short hopping intervals. Traditional direction of arrival (DOA) estimation algorithms are mainly based on features in the time domain, which are not suitable for FH signals. In this paper, we propose a new frequency domain DOA estimation algorithm for frequency hopping signals. The proposed algorithm firstly transforms the received signals into frequency domain by fast Fourier transform (FFT), then constructs the covariance matrix based on the characteristic of Toeplitz matrix. Finally, the low complexity root-MUSIC algorithm is utilized to obtain precise DOA estimates. Compared with the other traditional methods, the proposed algorithm can obtain superior performance with fewer number of snapshots and requires fewer number of antennas, which reduces the costs of the equipment and computational burden. Simulation results and real-data tests verify the effectiveness of the proposed algorithm.