Direction Finding for Communication Signals with Cyclostationarity and Time-modulated Array

In this paper, a novel direction-finding method for communication signals with low modulation frequency based on time-modulated array is proposed. By utilizing the cyclostationarity of communication signals and introducing a second channel, harmonics are compressed to be several discreet cyclic frequency spectrum lines where information of harmonics can be extracted from the aliased frequency spectrum so that the direction can be successfully estimated when the modulation frequency is lower than the bandwidth of the incident signal. Numerical simulation results are given to demonstrate the feasibility of the proposed method.