Multi-Hop STAR-RIS using Quantum Approximate Optimization Algorithm for Path Selection
Nadhira Azizah Suwanda, Soo Young Shin · 2025
In a reconfigurable intelligent surface (RIS), signals can be reflected more than once, a process known as multihop. Previously, the coverage of RIS multiple hops was limited to 180 •. Simultaneously transmitting and reflecting (STAR)-RIS enables 360 • beam coverage, allowing user positioning anywhere. Moreover, this study utilizes a quantum approximate optimization algorithm (QAOA) that encode the graph information in the routing problem to cost and mixer Hamiltonian. The proposed system is compared with the classical algorithm, which are optimal and myopic routing algorithm. The simulation results demonstrate that multi-hop STAR-RIS using QAOA has comparable effective channel power with relatively low computational complexity compared to the conventional multi-hop (CRIS) and classical algorithm, respectively.