A Low-Complexity Reflection Design Method for RIS-aided MIMO Systems

In this paper, we propose a reflection design solution for a single-user reconfigurable intelligent surface aided mmWave MIMO communication system with multiple streams, by formulating it as a spectral efficiency maximization problem. A heuristic low-complexity reflection design (LCRD) method is proposed in the form of a non-iterative algorithm. It is then compared to benchmark methods and is found to demonstrate an extremely low complexity rendering it highly efficient for practical applications with only a slight trade-off in accuracy as compared to more computationally intensive methods.