This code provides the source files and generation codes of all the figure in this paper:

• J. An et al., "Two-Dimensional Direction-of-Arrival Estimation Using Stacked Intelligent Metasurfaces," in IEEE Journal on Selected Areas in Communications, vol. 42, no. 10, pp. 2786-2802, Oct. 2024.
  

Bib

@ARTICLE{JSAC_2024_An_Two,
author={An, Jiancheng and Yuen, Chau and Guan, Yong Liang and Renzo, Marco Di and Debbah, Mérouane and Poor, H. Vincent and Hanzo, Lajos},
journal={IEEE J. Sel. Areas Commun.},
title={Two-Dimensional Direction-of-Arrival Estimation Using Stacked Intelligent Metasurfaces},
year={2024},
month={Oct.},
volume={42},
number={10},
pages={2786-2802},
doi={10.1109/JSAC.2024.3414613}}

Figure List

• Fig. 1. Photographs of some existing SIMs. (a) A three-layer SIM; (b) A five-layer SIM.
• Fig. 2. The considered SIM-aided array system.
• Fig. 3. Top and front views of the considered SIM-based systems.
• Fig. 4. The proposed SIM-based DOA estimation protocol, where different colors refer to non-overlapping spatial frequency bins associated with different snapshots. This is achieved by adjusting the phase shifts of the input metasurface layer. The vertical and horizontal lines correspond to $\psi_x$ and $\psi_y$, respectively.
• Tab. I. Normalized loss function (in dB) based on a (2, 2) grid points
• Tab. II. Normalized loss function (in dB) based on a (4, 4) grid points
• Fig. 5 Convergence behavior of the proposed gradient descent algorithm based on a (2, 2) grid points
  • Fig. 5(a) Normalized loss function $\mathcal{L}$ versus the number of iterations
  • Fig. 5(b) Normalized loss function $\mathcal{L}$ versus the decay parameter $\zeta$
• Fig. 6 Convergence behavior of the proposed gradient descent algorithm based on a (4, 4) grid points
  • Fig. 6(a) Normalized loss function $\mathcal{L}$ versus the number of iterations
  • Fig. 6(b) Normalized loss function $\mathcal{L}$ versus the decay parameter $\zeta$