Downlink Sum-Rate Maximization of 5G Networks With Metasurface-Based Reconfigurable Antennas

Due to their ability to manipulate electromagnetic (EM) fields with high flexibility and low-cost implementation, metasurfaces have emerged as a promising technology to enhance the performance of cellular networks. We propose a novel reconfigurable antenna using transmitting metasurfaces for cellular base stations. This antenna is formed by surrounding radiating elements with multiple metasurfaces that can be configured to be transparent or absorptive to electromagnetic waves. This increases the directionality of the resulting emitted signal, improves reception, and limits interference. We present a baseband equivalent channel model for downlink transmission that incorporates the reconfigurable antenna and describes the diffraction phenomena resulting from the metasurfaces' specific configuration. Next, we optimize the metasurface configuration, the transmit and receive beamformers, and the transmit power at multiple coordinated base stations to maximize the network sum-rate. Numerical results in a fifth generation (5G) networks confirm that the proposed structure considerably increases the sum-rate compared to traditional antenna arrays.