Optimal Design of RDARS-aided Multi-user Systems with Low-resolution DACs

Recently, a flexible reconfigurable architecture called reconfigurable distributed antenna and reflecting surface (RDARS), which maintains the advantages of distributed antennas while reducing hardware costs, has been proposed. In this paper, we investigate the appealing benefits of the RDARS’s architecture by considering an RDARS-aided downlink communication system under the limited resolution of digital-to-analog converters (DACs) and phase shifts. The dynamic selection of the reflection/connection modes at the RDARS and the reflective phase coefficients are optimized to maximize the communication rate. To tackle the mix-integer optimization problem, an inexact block coordinate descent (BCD) algorithm is then proposed. Numerical simulations demonstrate great superiority for the proposed RDARS-aided architecture as compared to the conventional benchmarks and show potential benefits in compensating for the limited resolution of hardware.