Power-Saving Design for Holographic Metasurface Enabled NOMA Communications

In this work the downlink non-orthogonal multiple access (NOMA) communications conducted by a holographic metasurface (HMTS) based transmitter with a single RF chain is investigated. The required transmit power for the transmitter to maintain the quality of service (QoS) of all users is derived. And two holographic beamforming schemes aiming at minimizing the required transmit power are developed. The first design is based on the semi-definite relaxation (SDR) of the required transmit power minimization problem while the second design is based on the optimal partitioning of the HMTS. Numerical results are provided to show the superiority of our proposed schemes.