Abstract: The angle of arrival (DOA) estimation of millimeter-wave signal source varies with frequency, which leads to large estimation error. A DOA estimation algorithm for millimeter-wave signal conversion to narrowband signal is proposed in this study. By establishing a millimeter wave signal reception model in the frequency domain, the proposed algorithm treats receiving signals as multiple unrelated narrowband signals and “focuses” them on a reference frequency in order to reduce the impact of the beam due to frequency changes, and then uses the ESPRIT algorithm to make millimeter wave DOA estimation. The simulation results show that the proposed algorithm may effectively reduce the DOA estimation error under moderate signal-to-noise ratio. When the number of array elements reaches 70, a relatively stable DOA estimation can be achieved, which can improve the link quality for directional transmission of millimeter-wave systems.

Key words: millimeter wave, DOA, narrow band model, focus, ESPRIT algorithm