Fast Beamforming Power Minimization in NOMA Unicast and Multicast Systems With Rate Guarantees

We propose fast beamforming algorithms for minimizing the power consumption of wireless communications while assuring unicast and multicast data rates in NOMA wireless networks. Specifically, we put forward the greedy backward substitution algorithm for unicast beamforming design and the Gram-Schmidt rotation algorithm for multicast beamforming design. The proposed approach adopts zero-forcing techniques, orthogonalization and rotation but does not have to solve complicated convex optimization problems. In addition, we derive novel analytical results for the studied problem. Simulation results indicate that the proposed approach outperforms a number of alternative schemes in the literature in terms of beamforming power consumption and computational complexity.