Beamspace Spatial Smoothing MUSIC DOA Estimation Method Using Dynamic Metasurface Antenna

The Direction-of-Arrival (DOA) estimation method using traditional array antennas cannot dynamically adjust the observation angle range based on the Region of Interest (ROI), which leads to limited estimation accuracy and high computational complexity. To address the above issue, this paper proposes a Beamspace Spatial Smoothing MUltiple SIgnal Classification (BSS-MUSIC) DOA estimation method using a Dynamic Metasurface Antenna (DMA). Specifically, we propose a new DMA model with a single RF chain and exploit its flexibility to design a time-division data reception scheme. Based on this scheme, we dynamically select the ROI and increase the beam density in the ROI with an appropriate number of beam patterns. Next, a BSS algorithm is proposed to decohere the multipath signals in beamspace without reverting to the element space. Subsequently, we convert the 2D DOA estimation into two 1D beamspace MUSIC DOA estimations. After pairing the elevation and azimuth angles, the complex gains of each path are derived. Simulation results show that the proposed method can achieve higher estimation accuracy with lower computational complexity.