  The DOA estimation method of coherent signals based on periodical coding
metasurface is proposed. After periodical coding, the DOA information of
incident signals in the time domain is represented as the amplitude and phase
information at different frequency points in the frequency domain. Finite time
Fourier transform (FTFT) is performed on the received signal and appropriate
frequency points are selected to reconstruct the frequency domain snapshot,
then pattern smoothing (PS) technique is applied to execute DOA estimation.
Compared with conventional DOA estimation methods, the proposed method has two
main advantages: one is that only a single receiving channel is needed to avoid
the appearance of channel mismatch errors, the other is that it can process
with multiple coherent signals. The performance curves of the proposed method
are analyzed under different conditions and compared with existing methods.
Simulation results show the effectiveness of the proposed method.
