Adaptability of quantum annealing for 1-bit MIMO design to RIS phase-shift optimization

Determine whether the quantum annealing approach used for the b = 2 (1-bit) pre- and post-coding design in MIMO systems can be adapted to reconfigurable intelligent surface (RIS) phase-shift optimization, where the phase shifts are continuous and can be directly represented by rotation gates in a quantum circuit.

Background

The paper contrasts its QAOA-based framework, which handles higher-order terms and maps phase shifts to rotation gates, with earlier work that used quantum annealing for the special case b = 2. The authors argue their approach naturally extends to problems like RIS phase-shift optimization that involve continuous phase values.

They explicitly state that it is unclear whether the prior quantum annealing method can be adapted to RIS optimization, identifying a concrete unresolved question about method transferability between discrete and continuous phase settings.

References

Moreover, the proposed framework can naturally extend to other challenging wireless network applications, such as RIS phase shift optimization, whereas it is unclear whether the solution of [5],[6] could be adapted.

— Quantum Approximate Optimization Algorithm for MIMO with Quantized b-bit Beamforming (2510.15935 - Mitsiou et al., 7 Oct 2025) in Introduction, Motivation and Contribution subsection